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#42283 From: "Dan" <imaginationstours@...>
Date: Fri Apr 27, 2012 2:03 pm
Subject: Re: Stopping and restorting a run
imaginationsfun
Send Email Send Email
 
Do you draw off and discord some as foreshots when re starting?

--- In new_distillers@yahoogroups.com, "Ed Barcik" <edbar44@...> wrote:
>
> I've done it many times, no problems, just keep the cooling water going
> until it cools down a little and you can restart it any time.
>

#42284 From: "gavinflett" <gavin_flett@...>
Date: Sat Apr 28, 2012 11:35 pm
Subject: My reflux column
gavinflett
Send Email Send Email
 
Ok guys, I need to get some reflux column experts to weigh in on this one. I
built an offset reflux head. It's about 6' tall and 2" thick. I'm using an
electric hotplate that puts out up to 1600W. I'm also doing this outside and
it'a bit chilly at 11C, but I have the whole thing insulated including the
column.

Now.... i'm only getting about 90% out this thing right now. It's been going for
8 hours now and have only collected about 3 or 4L. The most I got out this thing
was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this
thing? Why is it coming out so slow, and why isn't it more potent?

#42285 From: Bob Glicksman <bobg542492@...>
Date: Sun Apr 29, 2012 12:39 am
Subject: Re: My reflux column
robertglicksman
Send Email Send Email
 
This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?


#42286 From: Gavin Flett <gavin_flett@...>
Date: Sun Apr 29, 2012 1:30 am
Subject: RE: My reflux column
gavinflett
Send Email Send Email
 
You definitely talk good sense mister.

Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?

I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit. 


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 20:39:43 -0400
Subject: Re: [new_distillers] My reflux column

 

This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?



#42287 From: "gavinflett" <gavin_flett@...>
Date: Sun Apr 29, 2012 2:40 am
Subject: Sodium Bicarbonate
gavinflett
Send Email Send Email
 
How long does it take for sodium bicarbonate to turn the acetic acid back into
ethanol? If I added some in the afternoon, will it be ready by morning?

#42288 From: Bob Glicksman <bobg542492@...>
Date: Sun Apr 29, 2012 3:20 am
Subject: Re: My reflux column
robertglicksman
Send Email Send Email
 
Please let us know how turning down the heat turned out.  As to your question about reflux, the answer depends upon what type of reflux management system you use.  Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant).  Cooling the water will help, but you will achieve greater results by upping the flow rate.  Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux.  So you take less product to increase the reflux ratio. 
 
I suggest that you get a copy of Nixon and McCaw from The Amphora Society website.  The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.


-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 6:30 pm
Subject: RE: [new_distillers] My reflux column

 
You definitely talk good sense mister.

Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?

I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit. 


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 20:39:43 -0400
Subject: Re: [new_distillers] My reflux column

 

This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?



#42289 From: Gavin Flett <gavin_flett@...>
Date: Sun Apr 29, 2012 3:39 am
Subject: RE: My reflux column
gavinflett
Send Email Send Email
 
Lowering the power did not seem to make a difference. I am now collecting the distillate at about 87%. Maybe it's just near the end of the run, but the temp still reads 79C.


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 23:20:24 -0400
Subject: Re: [new_distillers] My reflux column

 

Please let us know how turning down the heat turned out.  As to your question about reflux, the answer depends upon what type of reflux management system you use.  Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant).  Cooling the water will help, but you will achieve greater results by upping the flow rate.  Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux.  So you take less product to increase the reflux ratio. 
 
I suggest that you get a copy of Nixon and McCaw from The Amphora Society website.  The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.


-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 6:30 pm
Subject: RE: [new_distillers] My reflux column

 
You definitely talk good sense mister.

Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?

I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit. 


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 20:39:43 -0400
Subject: Re: [new_distillers] My reflux column

 

This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?




#42290 From: "gavinflett" <gavin_flett@...>
Date: Mon Apr 30, 2012 5:04 am
Subject: Higher Alcohols
gavinflett
Send Email Send Email
 
What do you guys do with your Propanol portions as they come off the still. Are
these supposed to be drinkable? Or do they get used as weed killer?

I have mine separated and they don'e smell quite like the ethanol that came off.
I'm wondering if I should be filtering these along with the ethanol or not.

#42291 From: Bob Glicksman <bobg542492@...>
Date: Mon Apr 30, 2012 6:02 am
Subject: Re: My reflux column
robertglicksman
Send Email Send Email
 
Here are a few suggestions, Gavin:
 
1.  Check that everything is as it should be.  Is your column well insulated?  Is the packing clean and the vors running freely through it?  Is the still running at atmospheric pressure (no pressure buildup, e.g. due to clogged packing)?
 
2.  Make sure that your temperature probe is measuring only vapor and only above the packing.
 
3.  Is temperature your sole detemrination of proof or have you checked this with a hydrometer?  If the latter, do you compenate the hydometer reading for the temperature?
 
4.  Have you checked to make sure that your temperature probe is reading accurately?  Try testing it in boiling water and make sure to adjust the boiling point for altitude if you are not near sea level. 
 
5.  Make sure (as best that you can determine) that the vapors ascend through the packing evenly and that reflux runs down the center of the column and not down th walls of the column.
 
6.  After clearing the above, do what Nixon and McCaw recommend and run at 100% reflux ratio (all product gets poured back down the center of the column).  Wait for the column to reestablish equilibrium and see what your proof/temperature is.  If the proof is not at azeotrope, then you either (a) have too much heat going in and the vapors are ascending through the packing too fast, reducing its real HETP, or (c) you do not have enough cooling capacity in your condensors and you can't get get the heat back out even with your reduced heat input, or (c) your packing HETP is too low.  If you get to this step without a resolution, please post the details of your still and lets run through some numbers:
 
- boiler heat (what you are running at).
- proof of the beer (and how did you determine this?).
- column height and packing material.
- column diameter.
- still head configuration and reflux configuration (CM, LM, VM)
- how many condensers and where are they located
- what are you running through the condensors (water, beer, other) and at what temperature.  Do you have a way to measure coolant flow rate through the condensors and what is it?
 
There isn't a whole lot more to this.  A basic batch reflux column still that is well insulated from heat loss only has a few relevant variables to work with:
- proof of the beer
- heat input, which in conjunction with column diameter determines the vapor flow rate up the column (which can't be too fast or your HETP will be a lot lower than you think it is).
- heat output, which MUST balnace heat input and if you can't remove enough heat via the condensors, will limit the proof that you can get.
- column height and HETP of the packing, which, in conjunction with reflux ratio and heat removal, determines the proof of the product.
- measurement technique (which, if in error, will mislead you).
 
KR,
Bob
 


 
-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 8:46 pm
Subject: RE: [new_distillers] My reflux column

 
Lowering the power did not seem to make a difference. I am now collecting the distillate at about 87%. Maybe it's just near the end of the run, but the temp still reads 79C.


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 23:20:24 -0400
Subject: Re: [new_distillers] My reflux column

 

Please let us know how turning down the heat turned out.  As to your question about reflux, the answer depends upon what type of reflux management system you use.  Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant).  Cooling the water will help, but you will achieve greater results by upping the flow rate.  Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux.  So you take less product to increase the reflux ratio. 
 
I suggest that you get a copy of Nixon and McCaw from The Amphora Society website.  The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.


-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 6:30 pm
Subject: RE: [new_distillers] My reflux column

 
You definitely talk good sense mister.

Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?

I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit. 


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 20:39:43 -0400
Subject: Re: [new_distillers] My reflux column

 

This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?




#42292 From: Gavin Flett <gavin_flett@...>
Date: Mon Apr 30, 2012 6:24 am
Subject: RE: My reflux column
gavinflett
Send Email Send Email
 
Hi Bob, thanks for the attention on this. Answers are below each question in red


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Mon, 30 Apr 2012 02:02:10 -0400
Subject: Re: [new_distillers] My reflux column

 

Here are a few suggestions, Gavin:
 
1.  Check that everything is as it should be.  Is your column well insulated?  Is the packing clean and the vors running freely through it?  Is the still running at atmospheric pressure (no pressure buildup, e.g. due to clogged packing)? Yes the column is well insulated. But I got my 93% when it wasn't insulated. After I put up the insulation, the reflux seems to stop and the ABV drops into the 80's.
 
2.  Make sure that your temperature probe is measuring only vapor and only above the packing. Yes
 
3.  Is temperature your sole detemrination of proof or have you checked this with a hydrometer? Yes  If the latter, do you compenate the hydometer reading for the temperature? It's read at the correct temp of 20C
 
4.  Have you checked to make sure that your temperature probe is reading accurately?  No Try testing it in boiling water and make sure to adjust the boiling point for altitude if you are not near sea level. I'm at sea level
 
5.  Make sure (as best that you can determine) that the vapors ascend through the packing evenly and that reflux runs down the center of the column and not down th walls of the column. How am I supposed to do that? I can't see inside the still. I have the column packed with copper mesh, I have no idea if it's allowing the vapours to travel through evenly. I can breath through the column, which I read was a way to determine the packing density.
 
6.  After clearing the above, do what Nixon and McCaw recommend and run at 100% reflux ratio (all product gets poured back down the center of the column).  Wait for the column to reestablish equilibrium and see what your proof/temperature is.  If the proof is not at azeotrope, then you either (a) have too much heat going in and the vapors are ascending through the packing too fast, reducing its real HETP, or (c) you do not have enough cooling capacity in your condensors and you can't get get the heat back out even with your reduced heat input, or (c) your packing HETP is too low.  If you get to this step without a resolution, please post the details of your still and lets run through some numbers: I managed to get at the most 93% ABV, but only for a short while, after that I had to increase the power to the still just so it wouldn't take 3 days to distill everything. My still charge was about 20L at 40%. So far it's been going for 15 hours and it's still reading 80.5-82C (which I think is slightly inaccurate as the still ran steady at about 77C for about 8 hours).
 
- boiler heat (what you are running at).
- proof of the beer (and how did you determine this?).
- column height and packing material.
- column diameter.
- still head configuration and reflux configuration (CM, LM, VM)
- how many condensers and where are they located
- what are you running through the condensors (water, beer, other) and at what temperature.  Do you have a way to measure coolant flow rate through the condensors and what is it?
 
There isn't a whole lot more to this.  A basic batch reflux column still that is well insulated from heat loss only has a few relevant variables to work with:
- proof of the beer
- heat input, which in conjunction with column diameter determines the vapor flow rate up the column (which can't be too fast or your HETP will be a lot lower than you think it is).
- heat output, which MUST balnace heat input and if you can't remove enough heat via the condensors, will limit the proof that you can get.
- column height and HETP of the packing, which, in conjunction with reflux ratio and heat removal, determines the proof of the product.
- measurement technique (which, if in error, will mislead you).
 
KR,
Bob
 


 
-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 8:46 pm
Subject: RE: [new_distillers] My reflux column

 
Lowering the power did not seem to make a difference. I am now collecting the distillate at about 87%. Maybe it's just near the end of the run, but the temp still reads 79C.


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 23:20:24 -0400
Subject: Re: [new_distillers] My reflux column

 

Please let us know how turning down the heat turned out.  As to your question about reflux, the answer depends upon what type of reflux management system you use.  Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant).  Cooling the water will help, but you will achieve greater results by upping the flow rate.  Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux.  So you take less product to increase the reflux ratio. 
 
I suggest that you get a copy of Nixon and McCaw from The Amphora Society website.  The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.


-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 6:30 pm
Subject: RE: [new_distillers] My reflux column

 
You definitely talk good sense mister.

Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?

I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit. 


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 20:39:43 -0400
Subject: Re: [new_distillers] My reflux column

 

This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?





#42293 From: White Bear <sha_man_1@...>
Date: Mon Apr 30, 2012 10:01 am
Subject: Re: Higher Alcohols
sha_man_1
Send Email Send Email
 
Gavin-
  These "Higher Alcohols" or Fore-shots, are poisonous.  They contain acetone, phenols, methanol and other nasties in proportion to the type and amount of mash made.  They are found in grain and fruit based mashes and are best cut from any of the alcohol collected for re-distillation or use.
 
  A good use for the fore-shots is to start camp fires, inside a lighter, weed killer etc.  By all means do not drink them.  Be well
White Bear

--- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:

From: gavinflett <gavin_flett@...>
Subject: [new_distillers] Higher Alcohols
To: new_distillers@yahoogroups.com
Date: Monday, April 30, 2012, 12:04 AM

 
What do you guys do with your Propanol portions as they come off the still. Are these supposed to be drinkable? Or do they get used as weed killer?

I have mine separated and they don'e smell quite like the ethanol that came off. I'm wondering if I should be filtering these along with the ethanol or not.


#42294 From: "Tom" <tomhawk412@...>
Date: Mon Apr 30, 2012 12:07 pm
Subject: Re: My reflux column
tomhawk412
Send Email Send Email
 
Bob,

Thank you for the detailed explanations.  There is one point that you discuss
that, although I do it, I do not understand the principle.  I am somewhat
confused about column insulation.

I have a 2" copper column, 60" long, topped of with a slant plate reflux
off-take section followed by a shotgun condenser section sitting on top of it. 
I have a 1" vapor management off-take above the slant plate and below the
condenser, taking off at 90 degrees to the column and feeding the vapor through
a 1" gate valve and then to a lieberg condenser for my primary out-put.

My column is insulated from the boiler to just below the shotgun condenser.  The
1" vapor management off-take is insulated from the take off point at the column
to the Lieberg condenser section, including the 1" gate valve.

Why is it necessary to insulate the column?  It seems to me, a relative newbee,
that as the column insulation value increases, the HETP would decrease.  There
has to be one heating-cooling-heating cycle for each theoretical plate section. 
It seems to me that too much insulation (ideal insulation) would reduce the HETP
to an effective value of 1.  Can you or anyone help me understand the need for
insulation along the column length.

Thank you,

Tom

--- In new_distillers@yahoogroups.com, Bob Glicksman <bobg542492@...> wrote:
>
>
> Here are a few suggestions, Gavin:
>
> 1.  Check that everything is as it should be.  Is your column well insulated? 
Is the packing clean and the vors running freely through it?  Is the still
running at atmospheric pressure (no pressure buildup, e.g. due to clogged
packing)?
>
> 2.  Make sure that your temperature probe is measuring only vapor and only
above the packing.
>
> 3.  Is temperature your sole detemrination of proof or have you checked this
with a hydrometer?  If the latter, do you compenate the hydometer reading for
the temperature?
>
> 4.  Have you checked to make sure that your temperature probe is reading
accurately?  Try testing it in boiling water and make sure to adjust the boiling
point for altitude if you are not near sea level.
>
> 5.  Make sure (as best that you can determine) that the vapors ascend through
the packing evenly and that reflux runs down the center of the column and not
down th walls of the column.
>
> 6.  After clearing the above, do what Nixon and McCaw recommend and run at
100% reflux ratio (all product gets poured back down the center of the column). 
Wait for the column to reestablish equilibrium and see what your
proof/temperature is.  If the proof is not at azeotrope, then you either (a)
have too much heat going in and the vapors are ascending through the packing too
fast, reducing its real HETP, or (c) you do not have enough cooling capacity in
your condensors and you can't get get the heat back out even with your reduced
heat input, or (c) your packing HETP is too low.  If you get to this step
without a resolution, please post the details of your still and lets run through
some numbers:
>
> - boiler heat (what you are running at).
> - proof of the beer (and how did you determine this?).
> - column height and packing material.
> - column diameter.
> - still head configuration and reflux configuration (CM, LM, VM)
> - how many condensers and where are they located
> - what are you running through the condensors (water, beer, other) and at what
temperature.  Do you have a way to measure coolant flow rate through the
condensors and what is it?
>
> There isn't a whole lot more to this.  A basic batch reflux column still that
is well insulated from heat loss only has a few relevant variables to work with:
> - proof of the beer
> - heat input, which in conjunction with column diameter determines the vapor
flow rate up the column (which can't be too fast or your HETP will be a lot
lower than you think it is).
> - heat output, which MUST balnace heat input and if you can't remove enough
heat via the condensors, will limit the proof that you can get.
> - column height and HETP of the packing, which, in conjunction with reflux
ratio and heat removal, determines the proof of the product.
> - measurement technique (which, if in error, will mislead you).
>
> KR,
> Bob
>
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 8:46 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> Lowering the power did not seem to make a difference. I am now collecting the
distillate at about 87%. Maybe it's just near the end of the run, but the temp
still reads 79C.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 23:20:24 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> Please let us know how turning down the heat turned out.  As to your question
about reflux, the answer depends upon what type of reflux management system you
use.  Collant management (CM) systems generally require a greater flow rate of
cooling water (or whatever you use for coolant).  Cooling the water will help,
but you will achieve greater results by upping the flow rate.  Liquid Management
(LM) and Vapor Management(VM) systems have a value that controls how much liquid
or vapor is taken off as product; the restis reflux.  So you take less product
to increase the reflux ratio.
>
> I suggest that you get a copy of Nixon and McCaw from The Amphora Society
website.  The book is excellent and after you read and digest it all, it will
save you countless hours of experimentation and wrong turns.
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 6:30 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> You definitely talk good sense mister.
>
>
> Yes, I did think that more heat would equal more product coming out. And I did
know that it has to be counteracted with more reflux, I was just unsure of how
that could be done (do I pump more water through, thus making the water colder).
I am still unsure of why insulating the column is better, wouldn't more reflux
happen if the column is air cooled all the way up (vapours are cooling,
condensing and revapourizing more times)?
>
>
> I turned down the heat to the point where the output is around a KW, hopefully
this will produce a purer spirit.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 20:39:43 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> This is just a guess, Gavin, but I'd say that you are puting in too much heat,
and/or not providing enough reflux and/or enough heat removal in your condenser.
Distillation is driven by basic physics -- whatever heat you put in must be
taken out.  Follow this analysis along, if you will:
>
> The latent heat of vaporization (LHV) is the heat energy that you must put
into a liquid at its boiling pint in order to vaporize it.  Conversely, in order
to liquify a vapor at the dew point, you need to remove the LHV.  When you have
a mixture of two substances in a liquid, each substance retains its individual
physical and chemical characteristics, including its LHV.  The LHV is an
intrinsic physical property of any substance and it turns out that the LHV of
ethanol, on a volume basis (not on a mole basis) is considerably lower than the
LHV for a similar volume of water.  Thus, if you boil off a beer that is 10%
ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water
(a point on the co-called "VLE" curve that you see all over the place when
discussing distillation).
>
> Now, your packed column performs some fractionating "magic" such that the
vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol
and 4% water.  But given the information above, it should be obvious that if you
vaporize off a quart of beer and want to get out a quart of azeotropic ethanol,
the energy that you remove will be less than the energy that you put in.  Since
the still column does not otherwise lose energy (it is well insulated) and does
not have a means to store energy, then this can't work - conservation of energy
says it can't work.  So what will happen if you try and remove all of the vapor
at the top of the column as product is that the proof MUST go down to the same
55% ethanol 45% water that you put in (for this example).  This is why you MUST
HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a
significant amount of condensed product back down the column so that it is
recycled enough times to remove all of the heat that physics says must be
removed.
>
> This is all covered well in Nixon and McCaw "The Compleat Distiller".  The
more heat that you put into your still, the more heat that your condensor must
remove, so if the condensor design is inadequate, you can't get high proof even
with 100% reflux ratio.  If you have enough heat removal capacity in your
condensor, you must still set your reflux ratio high enough remove the LHV using
the azeotrope.  You require a minimum reflux ratio if you have enough packing,
but your HETP may be too low, in which case you can compensate, but only by
increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the
proof up high enough (as indicated by the temperature of the vapors at the top
of the column) than you either must reduce the heat input to the still or
increase the heat removal (bigger or faster condensor).
>
> Lastly, Nixon and McCaw also make that point that too much heat can cause the
vapor to travel up the column too fast, negating the fractionating "magic" that
happens in the column packing.
>
> A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is
much more than you need.  Too much heat is BAD -- it does not make distillation
faster, as you might intuitively assume.  It only requires you to have more
packing HETP, higher reflux ratio, and more condenser capacity or else the proof
will go down, as you have already found out the hard way.
>
> Bob
>
>
>
> -----Original Message-----
> From: gavinflett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 4:35 pm
> Subject: [new_distillers] My reflux column
>
>
>
>
>
> Ok guys, I need to get some reflux column experts to weigh in on this one. I
built an offset reflux head. It's about 6' tall and 2" thick. I'm using an
electric hotplate that puts out up to 1600W. I'm also doing this outside and
it'a bit chilly at 11C, but I have the whole thing insulated including the
column.
>
> Now.... i'm only getting about 90% out this thing right now. It's been going
for 8 hours now and have only collected about 3 or 4L. The most I got out this
thing was 93%.
>
> My question is, why can't I get 96% (or whatever the maximum is) out of this
thing? Why is it coming out so slow, and why isn't it more potent?
>

#42295 From: "gavinflett" <gavin_flett@...>
Date: Mon Apr 30, 2012 3:39 pm
Subject: Re: Higher Alcohols
gavinflett
Send Email Send Email
 
Ok, again there is a mix up in terminology. Forget what I said about higher
alcohols, I want to know about the Propanols 1&2, the part that comes of after
the ethanol.

--- In new_distillers@yahoogroups.com, White Bear <sha_man_1@...> wrote:
>
> Gavin-
>   These "Higher Alcohols" or Fore-shots, are poisonous.  They contain
acetone, phenols, methanol and other nasties in proportion to the type and
amount of mash made.  They are found in grain and fruit based mashes and are
best cut from any of the alcohol collected for re-distillation or use.
>  
>   A good use for the fore-shots is to start camp fires, inside a lighter,
weed killer etc.  By all means do not drink them.  Be well
> White Bear
>
> --- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
> From: gavinflett <gavin_flett@...>
> Subject: [new_distillers] Higher Alcohols
> To: new_distillers@yahoogroups.com
> Date: Monday, April 30, 2012, 12:04 AM
>
>
>
>  
>
>
>
> What do you guys do with your Propanol portions as they come off the still.
Are these supposed to be drinkable? Or do they get used as weed killer?
>
> I have mine separated and they don'e smell quite like the ethanol that came
off. I'm wondering if I should be filtering these along with the ethanol or not.
>

#42296 From: "gavinflett" <gavin_flett@...>
Date: Mon Apr 30, 2012 3:43 pm
Subject: Re: My reflux column
gavinflett
Send Email Send Email
 
Yes! That is my question/understanding as well. Insulating the column never made
any sense to me either.

--- In new_distillers@yahoogroups.com, "Tom" <tomhawk412@...> wrote:
>
> Bob,
>
> Thank you for the detailed explanations.  There is one point that you discuss
that, although I do it, I do not understand the principle.  I am somewhat
confused about column insulation.
>
> I have a 2" copper column, 60" long, topped of with a slant plate reflux
off-take section followed by a shotgun condenser section sitting on top of it. 
I have a 1" vapor management off-take above the slant plate and below the
condenser, taking off at 90 degrees to the column and feeding the vapor through
a 1" gate valve and then to a lieberg condenser for my primary out-put.
>
> My column is insulated from the boiler to just below the shotgun condenser. 
The 1" vapor management off-take is insulated from the take off point at the
column to the Lieberg condenser section, including the 1" gate valve.
>
> Why is it necessary to insulate the column?  It seems to me, a relative
newbee, that as the column insulation value increases, the HETP would decrease. 
There has to be one heating-cooling-heating cycle for each theoretical plate
section.  It seems to me that too much insulation (ideal insulation) would
reduce the HETP to an effective value of 1.  Can you or anyone help me
understand the need for insulation along the column length.
>
> Thank you,
>
> Tom
>
> --- In new_distillers@yahoogroups.com, Bob Glicksman <bobg542492@> wrote:
> >
> >
> > Here are a few suggestions, Gavin:
> >
> > 1.  Check that everything is as it should be.  Is your column well
insulated?  Is the packing clean and the vors running freely through it?  Is the
still running at atmospheric pressure (no pressure buildup, e.g. due to clogged
packing)?
> >
> > 2.  Make sure that your temperature probe is measuring only vapor and only
above the packing.
> >
> > 3.  Is temperature your sole detemrination of proof or have you checked this
with a hydrometer?  If the latter, do you compenate the hydometer reading for
the temperature?
> >
> > 4.  Have you checked to make sure that your temperature probe is reading
accurately?  Try testing it in boiling water and make sure to adjust the boiling
point for altitude if you are not near sea level.
> >
> > 5.  Make sure (as best that you can determine) that the vapors ascend
through the packing evenly and that reflux runs down the center of the column
and not down th walls of the column.
> >
> > 6.  After clearing the above, do what Nixon and McCaw recommend and run at
100% reflux ratio (all product gets poured back down the center of the column). 
Wait for the column to reestablish equilibrium and see what your
proof/temperature is.  If the proof is not at azeotrope, then you either (a)
have too much heat going in and the vapors are ascending through the packing too
fast, reducing its real HETP, or (c) you do not have enough cooling capacity in
your condensors and you can't get get the heat back out even with your reduced
heat input, or (c) your packing HETP is too low.  If you get to this step
without a resolution, please post the details of your still and lets run through
some numbers:
> >
> > - boiler heat (what you are running at).
> > - proof of the beer (and how did you determine this?).
> > - column height and packing material.
> > - column diameter.
> > - still head configuration and reflux configuration (CM, LM, VM)
> > - how many condensers and where are they located
> > - what are you running through the condensors (water, beer, other) and at
what temperature.  Do you have a way to measure coolant flow rate through the
condensors and what is it?
> >
> > There isn't a whole lot more to this.  A basic batch reflux column still
that is well insulated from heat loss only has a few relevant variables to work
with:
> > - proof of the beer
> > - heat input, which in conjunction with column diameter determines the vapor
flow rate up the column (which can't be too fast or your HETP will be a lot
lower than you think it is).
> > - heat output, which MUST balnace heat input and if you can't remove enough
heat via the condensors, will limit the proof that you can get.
> > - column height and HETP of the packing, which, in conjunction with reflux
ratio and heat removal, determines the proof of the product.
> > - measurement technique (which, if in error, will mislead you).
> >
> > KR,
> > Bob
> >
> >
> >
> >
> > -----Original Message-----
> > From: Gavin Flett <gavin_flett@>
> > To: new_distillers <new_distillers@yahoogroups.com>
> > Sent: Sat, Apr 28, 2012 8:46 pm
> > Subject: RE: [new_distillers] My reflux column
> >
> >
> >
> >
> >
> > Lowering the power did not seem to make a difference. I am now collecting
the distillate at about 87%. Maybe it's just near the end of the run, but the
temp still reads 79C.
> >
> >
> >
> > To: new_distillers@yahoogroups.com
> > From: bobg542492@
> > Date: Sat, 28 Apr 2012 23:20:24 -0400
> > Subject: Re: [new_distillers] My reflux column
> >
> >
> >
> >
> >
> > Please let us know how turning down the heat turned out.  As to your
question about reflux, the answer depends upon what type of reflux management
system you use.  Collant management (CM) systems generally require a greater
flow rate of cooling water (or whatever you use for coolant).  Cooling the water
will help, but you will achieve greater results by upping the flow rate.  Liquid
Management (LM) and Vapor Management(VM) systems have a value that controls how
much liquid or vapor is taken off as product; the restis reflux.  So you take
less product to increase the reflux ratio.
> >
> > I suggest that you get a copy of Nixon and McCaw from The Amphora Society
website.  The book is excellent and after you read and digest it all, it will
save you countless hours of experimentation and wrong turns.
> >
> >
> >
> > -----Original Message-----
> > From: Gavin Flett <gavin_flett@>
> > To: new_distillers <new_distillers@yahoogroups.com>
> > Sent: Sat, Apr 28, 2012 6:30 pm
> > Subject: RE: [new_distillers] My reflux column
> >
> >
> >
> >
> >
> > You definitely talk good sense mister.
> >
> >
> > Yes, I did think that more heat would equal more product coming out. And I
did know that it has to be counteracted with more reflux, I was just unsure of
how that could be done (do I pump more water through, thus making the water
colder). I am still unsure of why insulating the column is better, wouldn't more
reflux happen if the column is air cooled all the way up (vapours are cooling,
condensing and revapourizing more times)?
> >
> >
> > I turned down the heat to the point where the output is around a KW,
hopefully this will produce a purer spirit.
> >
> >
> >
> > To: new_distillers@yahoogroups.com
> > From: bobg542492@
> > Date: Sat, 28 Apr 2012 20:39:43 -0400
> > Subject: Re: [new_distillers] My reflux column
> >
> >
> >
> >
> >
> > This is just a guess, Gavin, but I'd say that you are puting in too much
heat, and/or not providing enough reflux and/or enough heat removal in your
condenser.  Distillation is driven by basic physics -- whatever heat you put in
must be taken out.  Follow this analysis along, if you will:
> >
> > The latent heat of vaporization (LHV) is the heat energy that you must put
into a liquid at its boiling pint in order to vaporize it.  Conversely, in order
to liquify a vapor at the dew point, you need to remove the LHV.  When you have
a mixture of two substances in a liquid, each substance retains its individual
physical and chemical characteristics, including its LHV.  The LHV is an
intrinsic physical property of any substance and it turns out that the LHV of
ethanol, on a volume basis (not on a mole basis) is considerably lower than the
LHV for a similar volume of water.  Thus, if you boil off a beer that is 10%
ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water
(a point on the co-called "VLE" curve that you see all over the place when
discussing distillation).
> >
> > Now, your packed column performs some fractionating "magic" such that the
vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol
and 4% water.  But given the information above, it should be obvious that if you
vaporize off a quart of beer and want to get out a quart of azeotropic ethanol,
the energy that you remove will be less than the energy that you put in.  Since
the still column does not otherwise lose energy (it is well insulated) and does
not have a means to store energy, then this can't work - conservation of energy
says it can't work.  So what will happen if you try and remove all of the vapor
at the top of the column as product is that the proof MUST go down to the same
55% ethanol 45% water that you put in (for this example).  This is why you MUST
HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a
significant amount of condensed product back down the column so that it is
recycled enough times to remove all of the heat that physics says must be
removed.
> >
> > This is all covered well in Nixon and McCaw "The Compleat Distiller".  The
more heat that you put into your still, the more heat that your condensor must
remove, so if the condensor design is inadequate, you can't get high proof even
with 100% reflux ratio.  If you have enough heat removal capacity in your
condensor, you must still set your reflux ratio high enough remove the LHV using
the azeotrope.  You require a minimum reflux ratio if you have enough packing,
but your HETP may be too low, in which case you can compensate, but only by
increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the
proof up high enough (as indicated by the temperature of the vapors at the top
of the column) than you either must reduce the heat input to the still or
increase the heat removal (bigger or faster condensor).
> >
> > Lastly, Nixon and McCaw also make that point that too much heat can cause
the vapor to travel up the column too fast, negating the fractionating "magic"
that happens in the column packing.
> >
> > A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is
much more than you need.  Too much heat is BAD -- it does not make distillation
faster, as you might intuitively assume.  It only requires you to have more
packing HETP, higher reflux ratio, and more condenser capacity or else the proof
will go down, as you have already found out the hard way.
> >
> > Bob
> >
> >
> >
> > -----Original Message-----
> > From: gavinflett <gavin_flett@>
> > To: new_distillers <new_distillers@yahoogroups.com>
> > Sent: Sat, Apr 28, 2012 4:35 pm
> > Subject: [new_distillers] My reflux column
> >
> >
> >
> >
> >
> > Ok guys, I need to get some reflux column experts to weigh in on this one. I
built an offset reflux head. It's about 6' tall and 2" thick. I'm using an
electric hotplate that puts out up to 1600W. I'm also doing this outside and
it'a bit chilly at 11C, but I have the whole thing insulated including the
column.
> >
> > Now.... i'm only getting about 90% out this thing right now. It's been going
for 8 hours now and have only collected about 3 or 4L. The most I got out this
thing was 93%.
> >
> > My question is, why can't I get 96% (or whatever the maximum is) out of this
thing? Why is it coming out so slow, and why isn't it more potent?
> >
>

#42297 From: White Bear <sha_man_1@...>
Date: Mon Apr 30, 2012 7:34 pm
Subject: Re: Re: Higher Alcohols
sha_man_1
Send Email Send Email
 
Gavin-
  attached is the description of Propanols 1 & 2 from Wikipedia.  I had to look it up myself to be sure the proper identification.
White Bear

--- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:

From: gavinflett <gavin_flett@...>
Subject: [new_distillers] Re: Higher Alcohols
To: new_distillers@yahoogroups.com
Date: Monday, April 30, 2012, 10:39 AM

 
Ok, again there is a mix up in terminology. Forget what I said about higher alcohols, I want to know about the Propanols 1&2, the part that comes of after the ethanol.

--- In new_distillers@yahoogroups.com, White Bear <sha_man_1@...> wrote:
>
> Gavin-
>   These "Higher Alcohols" or Fore-shots, are poisonous.  They contain acetone, phenols, methanol and other nasties in proportion to the type and amount of mash made.  They are found in grain and fruit based mashes and are best cut from any of the alcohol collected for re-distillation or use.
>  
>   A good use for the fore-shots is to start camp fires, inside a lighter, weed killer etc.  By all means do not drink them.  Be well
> White Bear
>
> --- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
> From: gavinflett <gavin_flett@...>
> Subject: [new_distillers] Higher Alcohols
> To: new_distillers@yahoogroups.com
> Date: Monday, April 30, 2012, 12:04 AM
>
>
>
>  
>
>
>
> What do you guys do with your Propanol portions as they come off the still. Are these supposed to be drinkable? Or do they get used as weed killer?
>
> I have mine separated and they don'e smell quite like the ethanol that came off. I'm wondering if I should be filtering these along with the ethanol or not.
>


1 of 1 File(s)


#42298 From: "gavinflett" <gavin_flett@...>
Date: Mon Apr 30, 2012 8:42 pm
Subject: Re: Higher Alcohols
gavinflett
Send Email Send Email
 
Thanks White bear.

I looked it up myself and specifically I meant Propanol-2 with a boiling point
of 82.5C. So I understand from Wikipedia that this gets separated from the
ethanol by adding basically some form of salt. How do I know which layer is the
Propanol-2 and which is the Ethanol.

If some Propanol gets in with my ethanol, should I get it out? Can I get it out?
How do I do that?

--- In new_distillers@yahoogroups.com, White Bear <sha_man_1@...> wrote:
>
> Gavin-
>   attached is the description of Propanols 1 & 2 from Wikipedia.  I had to
look it up myself to be sure the proper identification.
> White Bear
>
> --- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
> From: gavinflett <gavin_flett@...>
> Subject: [new_distillers] Re: Higher Alcohols
> To: new_distillers@yahoogroups.com
> Date: Monday, April 30, 2012, 10:39 AM
>
>
>
>  
>
>
>
> Ok, again there is a mix up in terminology. Forget what I said about higher
alcohols, I want to know about the Propanols 1&2, the part that comes of after
the ethanol.
>
> --- In new_distillers@yahoogroups.com, White Bear <sha_man_1@> wrote:
> >
> > Gavin-
> >   These "Higher Alcohols" or Fore-shots, are poisonous.  They contain
acetone, phenols, methanol and other nasties in proportion to the type and
amount of mash made.  They are found in grain and fruit based mashes and are
best cut from any of the alcohol collected for re-distillation or use.
> >  
> >   A good use for the fore-shots is to start camp fires, inside a lighter,
weed killer etc.  By all means do not drink them.  Be well
> > White Bear
> >
> > --- On Mon, 4/30/12, gavinflett <gavin_flett@> wrote:
> >
> >
> > From: gavinflett <gavin_flett@>
> > Subject: [new_distillers] Higher Alcohols
> > To: new_distillers@yahoogroups.com
> > Date: Monday, April 30, 2012, 12:04 AM
> >
> >
> >
> >  
> >
> >
> >
> > What do you guys do with your Propanol portions as they come off the still.
Are these supposed to be drinkable? Or do they get used as weed killer?
> >
> > I have mine separated and they don'e smell quite like the ethanol that came
off. I'm wondering if I should be filtering these along with the ethanol or not.
> >
>

#42299 From: Bob Glicksman <bobg542492@...>
Date: Tue May 1, 2012 12:35 am
Subject: Re: My reflux column
robertglicksman
Send Email Send Email
 
Hi Gavin,
 
If you got higher proof when your column was uninsulated, then I would say that this is a clear indication that you don't have enough heat removal capacity in your condenser(s).  Remember conservation of energy -- the energy that goes into the still must all come out of the still.  However, you can't just radiate heat arbitrarily out the column wall because the fractionating "magic" that causes the ethanol and water to separate requires a very specific temperature gradient to exist up the length of the packing.  If the temperature gradient is not maintained exactly throughout the run, your column will fall out of equilibrium and the proof will go down (or the product rate will go down).  I never fully answered your question about taking heat off of the column walls, so I will do so below.  But the bottom line is that your condensor(s) is probably undersized for the heat that you are puting in. 
 
Figuring out the right size for a condensor is a little tough.  I forget the metric units, but in English units, 1 BTU raises one pound of water one degree F.  Recall that heat transfer can only take place from a higher temperature to a lower temperature.  To get azeotrope, the vapor temperature from which you are removing heat in the condenser(s) is the boiling point of the azeotrope which is something like 173 deg F.  If you are using cooling water at 73 degrees F to remove heat in the condenser, then at MOST you will be able to raise the water temperature 100 degress F (below boiling), therefore absorb 100 BTU of heat for every pound of water that flows through the condenser.  Convert pounds of water to liquid volume and you will know the minimum flow rate needed.  If you measure the input and output coolant temperature from your condenser(s) and the coolant flow rate, you can calculate the anount of heat energy that you are removing and compare this with the heat energy that you are puting into the column.  I'll bet that you don't have enough removal and need a larger condenser(s).
 
Here is why you must insulate your column.  The fractional distallation process upon which your still column works requires a constant heat exchange at various plates running up the column of the still.  You don't have actual plates with a packed column, but the principle is the same (you have 'theoretical plates" and the number of theoretical plates that you have depends upon the HETP of the packing material and the packing height).  Each plate in the column represents a mixture of ethanol and water that corresponds to a liquid/vapor equilibrium at some specific concentration of ethanol/water in the mixture.  The specifics are not arbitrary.  They are absolutely dictated by physics and depend only upon the initial concentration of ethanol/water in your beer.  If your beer is, say, 10% ethanol and 90% water (by volume), then physics dictates that the vapors resulting from boiling this mixture will contain 55% ethanol/45% water, by volume when condensed back to liquid.  You can't change this -- it is required by the laws of physics.  So your boiler, which is the first "plate" will be the the boiling point of a 10% ethanol/90% water mixture, your first theoretical plate in your column must be at the boiling point of a 55% ethanol/45% water liquid mixture, the next plate up must be at whatever the concentration ratio phsycis dictates , etc.  You can compute what physics dictates from the LHV of water and ethanol and the molar concentration at each step, or simply find it in a table or graph in a book (sorry, my copy of Nixon and McCaw is loaned out right now so I can't cite you the page and figure number, but it is there for sure).  In any event, each plate (real or theoretical) in your column must be maintained at the specific temperature that is the boiling point of the mixture at that plate, as required by the physics of liquid/vapor equilibrium (LVE).  If the column is not held precisely in this state of equilibirum, your production and proof will change.  So however you do it, you are required, by the laws of physics, to keep the column in exact equilibrium.
 
Now you can see why simply removing insulation won't work.  You have no way of precisely controlling the heat transfer out of the walls of the column.  Yes, you will lose heat (which in your case is necessary) but you can't lose it in precisely the way to maintain the temperature gradient up the packing that is required to maintain equilibirum.  The temperature and degree of airflow past the column will change and the heat removed will at best be even up the column and more generally be determined by air currents and imprefections in the column wall and will in no way represent what is needed to maintain equilibrium.
 
Now, it is not impossible to do what you were thinking.  You could insulate the column really well and put a computer controlled heat exchanger on each plate (if you had real plates) and control the heat removal on each plate to keep that plate at the precise temperature that equilibrium requires.  This, in fact, is exactly what the petrochemical industry does.  An oil refinery is just a large fractionating column where it is desired to take off product from each plate -- gasoline has the lowest boiling point, followed by diesel fuel, kerosine, light lubricating oil, bunker oil, heavy lubricating oil, etc.  The technology to do this on a small ethanol still is not beyond the reach of an individual distiller, but the question is:  why would you want to go to all of this troube if you are only interested in separating ethanol from water?  Some smart person figured out, a long time ago, that you can maintain still colimn equilibrium via only one measurement and one control -- by sending some condensed product back down the still column (reflux).  This is a whole lot easier and cheaper than physically controlling the temperature of each plate and it works with continuous packing as well as with discrete plates.  So this is why reflux is required.
 
Bob
 
 
 

 
-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sun, Apr 29, 2012 11:24 pm
Subject: RE: [new_distillers] My reflux column

 
Hi Bob, thanks for the attention on this. Answers are below each question in red


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Mon, 30 Apr 2012 02:02:10 -0400
Subject: Re: [new_distillers] My reflux column

 

Here are a few suggestions, Gavin:
 
1.  Check that everything is as it should be.  Is your column well insulated?  Is the packing clean and the vors running freely through it?  Is the still running at atmospheric pressure (no pressure buildup, e.g. due to clogged packing)? Yes the column is well insulated. But I got my 93% when it wasn't insulated. After I put up the insulation, the reflux seems to stop and the ABV drops into the 80's.
 
2.  Make sure that your temperature probe is measuring only vapor and only above the packing. Yes
 
3.  Is temperature your sole detemrination of proof or have you checked this with a hydrometer? Yes  If the latter, do you compenate the hydometer reading for the temperature? It's read at the correct temp of 20C
 
4.  Have you checked to make sure that your temperature probe is reading accurately?  No Try testing it in boiling water and make sure to adjust the boiling point for altitude if you are not near sea level. I'm at sea level
 
5.  Make sure (as best that you can determine) that the vapors ascend through the packing evenly and that reflux runs down the center of the column and not down th walls of the column. How am I supposed to do that? I can't see inside the still. I have the column packed with copper mesh, I have no idea if it's allowing the vapours to travel through evenly. I can breath through the column, which I read was a way to determine the packing density.
 
6.  After clearing the above, do what Nixon and McCaw recommend and run at 100% reflux ratio (all product gets poured back down the center of the column).  Wait for the column to reestablish equilibrium and see what your proof/temperature is.  If the proof is not at azeotrope, then you either (a) have too much heat going in and the vapors are ascending through the packing too fast, reducing its real HETP, or (c) you do not have enough cooling capacity in your condensors and you can't get get the heat back out even with your reduced heat input, or (c) your packing HETP is too low.  If you get to this step without a resolution, please post the details of your still and lets run through some numbers: I managed to get at the most 93% ABV, but only for a short while, after that I had to increase the power to the still just so it wouldn't take 3 days to distill everything. My still charge was about 20 L at 40%. So far it's been going for 15 hours and it's still reading 80.5-82C (which I think is slightly inaccurate as the still ran steady at about 77C for about 8 hours).
 
- boiler heat (what you are running at).
- proof of the beer (and how did you determine this?).
- column height and packing material.
- column diameter.
- still head configuration and reflux configuration (CM, LM, VM)
- how many condensers and where are they located
- what are you running through the condensors (water, beer, other) and at what temperature.  Do you have a way to measure coolant flow rate through the condensors and what is it?
 
There isn't a whole lot more to this.  A basic batch reflux column still that is well insulated from heat loss only has a few relevant variables to work with:
- proof of the beer
- heat input, which in conjunction with column diameter determines the vapor flow rate up the column (which can't be too fast or your HETP will be a lot lower than you think it is).
- heat output, which MUST balnace heat input and if you can't remove enough heat via the condensors, will limit the proof that you can get.
- column height and HETP of the packing, which, in conjunction with reflux ratio and heat removal, determines the proof of the product.
- measurement technique (which, if in error, will mislead you).
 
KR,
Bob
 


 
-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 8:46 pm
Subject: RE: [new_distillers] My reflux column

 
Lowering the power did not seem to make a difference. I am now collecting the distillate at about 87%. Maybe it's just near the end of the run, but the temp still reads 79C.


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 23:20:24 -0400
Subject: Re: [new_distillers] My reflux column

 

Please let us know how turning down the heat turned out.  As to your question about reflux, the answer depends upon what type of reflux management system you use.  Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant).  Cooling the water will help, but you will achieve greater results by upping the flow rate.  Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux.  So you take less product to increase the reflux ratio. 
 
I suggest that you get a copy of Nixon and McCaw from The Amphora Society website.  The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.


-----Original Message-----
From: Gavin Flett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 6:30 pm
Subject: RE: [new_distillers] My reflux column

 
You definitely talk good sense mister.

Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?

I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit. 


To: new_distillers@yahoogroups.com
From: bobg542492@...
Date: Sat, 28 Apr 2012 20:39:43 -0400
Subject: Re: [new_distillers] My reflux column

 

This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser.  Distillation is driven by basic physics -- whatever heat you put in must be taken out.  Follow this analysis along, if you will:
 
The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it.  Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV.  When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV.  The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water.  Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
 
Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water.  But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in.  Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work.  So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example).  This is why you MUST HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remove all of the heat that physics says must be removed. 
This is all covered well in Nixon and McCaw "The Compleat Distiller".  The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio.  If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope.  You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor). 
 
Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
 
A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is much more than you need.  Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume.  It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
 
Bob
 
 
 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Sat, Apr 28, 2012 4:35 pm
Subject: [new_distillers] My reflux column

 
Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.

Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.

My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?





#42300 From: Bob Glicksman <bobg542492@...>
Date: Tue May 1, 2012 12:45 am
Subject: Re: Re: My reflux column
robertglicksman
Send Email Send Email
 
Tom,
 
 
Please see my reply to Gavin, which crossed your inquiry in time.  I believe that it answers your question.  You are most correct that heat must be removed from the still column, to balance the heat that enters via the vapor off of the boiler.  Removal of the proper amount of heat to keep the column at equilibrium is the job of reflux.  You must ensure that you have enough reflux to remove all of the heat.  Reflux is a clever and simple way to remove the heat in just the right way so that the column remains in equilibrium with the proper temperature gradient up the packing.  My reply to Gavin included another, more direct but a lot more expensive and complicated, way to do this.  But the bottom line is that just blowing air across an uninsulated column will not remove the correct amount of heat from each "plate" in the column and the column will therefore fall out of equilibrium.
 
Bob


-----Original Message-----
From: Tom <tomhawk412@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Mon, Apr 30, 2012 5:07 am
Subject: [new_distillers] Re: My reflux column

 
Bob,

Thank you for the detailed explanations. There is one point that you discuss that, although I do it, I do not understand the principle. I am somewhat confused about column insulation.

I have a 2" copper column, 60" long, topped of with a slant plate reflux off-take section followed by a shotgun condenser section sitting on top of it. I have a 1" vapor management off-take above the slant plate and below the condenser, taking off at 90 degrees to the column and feeding the vapor through a 1" gate valve and then to a lieberg condenser for my primary out-put.

My column is insulated from the boiler to just below the shotgun condenser. The 1" vapor management off-take is insulated from the take off point at the column to the Lieberg condenser section, including the 1" gate valve.

Why is it necessary to insulate the column? It seems to me, a relative newbee, that as the column insulation value increases, the HETP would decrease. There has to be one heating-cooling-heating cycle for each theoretical plate section. It seems to me that too much insulation (ideal insulation) would reduce the HETP to an effective value of 1. Can you or anyone help me understand the need for insulation along the column length.

Thank you,

Tom

--- In new_distillers@yahoogroups.com, Bob Glicksman <bobg542492@...> wrote:
>
>
> Here are a few suggestions, Gavin:
>
> 1. Check that everything is as it should be. Is your column well insulated? Is the packing clean and the vors running freely through it? Is the still running at atmospheric pressure (no pressure buildup, e.g. due to clogged packing)?
>
> 2. Make sure that your temperature probe is measuring only vapor and only above the packing.
>
> 3. Is temperature your sole detemrination of proof or have you checked this with a hydrometer? If the latter, do you compenate the hydometer reading for the temperature?
>
> 4. Have you checked to make sure that your temperature probe is reading accurately? Try testing it in boiling water and make sure to adjust the boiling point for altitude if you are not near sea level.
>
> 5. Make sure (as best that you can determine) that the vapors ascend through the packing evenly and that reflux runs down the center of the column and not down th walls of the column.
>
> 6. After clearing the above, do what Nixon and McCaw recommend and run at 100% reflux ratio (all product gets poured back down the center of the column). Wait for the column to reestablish equilibrium and see what your proof/temperature is. If the proof is not at azeotrope, then you either (a) have too much heat going in and the vapors are ascending through the packing too fast, reducing its real HETP, or (c) you do not have enough cooling capacity in your condensors and you can't get get the heat back out even with your reduced heat input, or (c) your packing HETP is too low. If you get to this step without a resolution, please post the details of your still and lets run through some numbers:
>
> - boiler heat (what you are running at).
> - proof of the beer (and how did you determine this?).
> - column height and packing material.
> - column diameter.
> - still head configuration and reflux configuration (CM, LM, VM)
> - how many condensers and where are they located
> - what are you running through the condensors (water, beer, other) and at what temperature. Do you have a way to measure coolant flow rate through the condensors and what is it?
>
> There isn't a whole lot more to this. A basic batch reflux column still that is well insulated from heat loss only has a few relevant variables to work with:
> - proof of the beer
> - heat input, which in conjunction with column diameter determines the vapor flow rate up the column (which can't be too fast or your HETP will be a lot lower than you think it is).
> - heat output, which MUST balnace heat input and if you can't remove enough heat via the condensors, will limit the proof that you can get.
> - column height and HETP of the packing, which, in conjunction with reflux ratio and heat removal, determines the proof of the product.
> - measurement technique (which, if in error, will mislead you).
>
> KR,
> Bob
>
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 8:46 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> Lowering the power did not seem to make a difference. I am now collecting the distillate at about 87%. Maybe it's just near the end of the run, but the temp still reads 79C.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 23:20:24 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> Please let us know how turning down the heat turned out. As to your question about reflux, the answer depends upon what type of reflux management system you use. Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant). Cooling the water will help, but you will achieve greater results by upping the flow rate. Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux. So you take less product to increase the reflux ratio.
>
> I suggest that you get a copy of Nixon and McCaw from The Amphora Society website. The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 6:30 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> You definitely talk good sense mister.
>
>
> Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?
>
>
> I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 20:39:43 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser. Distillation is driven by basic physics -- whatever heat you put in must be taken out. Follow this analysis along, if you will:
>
> The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it. Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV. When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV. The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water. Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
>
> Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water. But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in. Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work. So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example). This is why you MUST HAVE REFLUX. The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remov e all of the heat that physics says must be removed.
>
> This is all covered well in Nixon and McCaw "The Compleat Distiller". The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio. If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope. You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio. If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor).
>
> Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
>
> A 2" diameter column will be driven quite well by a 1 KW heater. 1.6 KW is much more than you need. Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume. It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
>
> Bob
>
>
>
> -----Original Message-----
> From: gavinflett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 4:35 pm
> Subject: [new_distillers] My reflux column
>
>
>
>
>
> Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.
>
> Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.
>
> My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?
>


#42301 From: "Tom" <tomhawk412@...>
Date: Tue May 1, 2012 1:05 am
Subject: Re: My reflux column
tomhawk412
Send Email Send Email
 
Bob,

I read your reply to Gavin.  Your explanation was very concise and to the point!
I now understand the need for insulating the column.  My system has been working
well with the insulation but I just did not understand the principle.  I do now.

Thank you for taking the time and effort to lay out a careful and methodical
explaination.

Regards,

Tom

--- In new_distillers@yahoogroups.com, Bob Glicksman <bobg542492@...> wrote:
>
>
> Tom,
>
>
> Please see my reply to Gavin, which crossed your inquiry in time.  I believe
that it answers your question.  You are most correct that heat must be removed
from the still column, to balance the heat that enters via the vapor off of the
boiler.  Removal of the proper amount of heat to keep the column at equilibrium
is the job of reflux.  You must ensure that you have enough reflux to remove all
of the heat.  Reflux is a clever and simple way to remove the heat in just the
right way so that the column remains in equilibrium with the proper temperature
gradient up the packing.  My reply to Gavin included another, more direct but a
lot more expensive and complicated, way to do this.  But the bottom line is that
just blowing air across an uninsulated column will not remove the correct amount
of heat from each "plate" in the column and the column will therefore fall out
of equilibrium.
>
> Bob
>
>SNIP

#42302 From: "lhill0349" <lhill0349@...>
Date: Tue May 1, 2012 3:29 am
Subject: vodka wash cuts
lhill0349
Send Email Send Email
 
I've had great success in whiskey production by carfully watching the cuts. I'm
trying a vodka wash run this time but haven't seen much info on the cuts. I'm
using a pot still and have already run the first distillation. Question is what
are the cut points for sugar wash vodka during the second distillation? I'm
running it all through a charcoal colume afterward. Is a third distillation of
any real value?

#42303 From: White Bear <sha_man_1@...>
Date: Tue May 1, 2012 9:41 am
Subject: Re: Re: Higher Alcohols
sha_man_1
Send Email Send Email
 
  It depends on what type of still you are using.  With a pot still, you will NOT be able to remove the Propanol's totally it's just not that efficient.  With much experience it is relatively easy to remove most of them by making cuts by nose and tossing the first 50ml - 100ml per 5gallons.  Things get easier with a reflux still and LM (liquid management) under total reflux.
  As to knowing which layer is Propanol and which is Ethanol - I go by volume and taste.  Through experience, you will develop a "Taste" for the cuts and a nose for the scent of ethanol.  Here I must remind you not to be greedy, if your cuts run into each other so-be-it, it's going to happen.  This will ensure you are getting the finest product that your still will allow.
White Bear

--- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:

From: gavinflett <gavin_flett@...>
Subject: [new_distillers] Re: Higher Alcohols
To: new_distillers@yahoogroups.com
Date: Monday, April 30, 2012, 3:42 PM

 
Thanks White bear.

I looked it up myself and specifically I meant Propanol-2 with a boiling point of 82.5C. So I understand from Wikipedia that this gets separated from the ethanol by adding basically some form of salt. How do I know which layer is the Propanol-2 and which is the Ethanol.

If some Propanol gets in with my ethanol, should I get it out? Can I get it out? How do I do that?

--- In new_distillers@yahoogroups.com, White Bear <sha_man_1@...> wrote:
>
> Gavin-
>   attached is the description of Propanols 1 & 2 from Wikipedia.  I had to look it up myself to be sure the proper identification.
> White Bear
>
> --- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
> From: gavinflett <gavin_flett@...>
> Subject: [new_distillers] Re: Higher Alcohols
> To: new_distillers@yahoogroups.com
> Date: Monday, April 30, 2012, 10:39 AM
>
>
>
>  
>
>
>
> Ok, again there is a mix up in terminology. Forget what I said about higher alcohols, I want to know about the Propanols 1&2, the part that comes of after the ethanol.
>
> --- In new_distillers@yahoogroups.com, White Bear <sha_man_1@> wrote:
> >
> > Gavin-
> >   These "Higher Alcohols" or Fore-shots, are poisonous.  They contain acetone, phenols, methanol and other nasties in proportion to the type and amount of mash made.  They are found in grain and fruit based mashes and are best cut from any of the alcohol collected for re-distillation or use.
> >  
> >   A good use for the fore-shots is to start camp fires, inside a lighter, weed killer etc.  By all means do not drink them.  Be well
> > White Bear
> >
> > --- On Mon, 4/30/12, gavinflett <gavin_flett@> wrote:
> >
> >
> > From: gavinflett <gavin_flett@>
> > Subject: [new_distillers] Higher Alcohols
> > To: new_distillers@yahoogroups.com
> > Date: Monday, April 30, 2012, 12:04 AM
> >
> >
> >
> >  
> >
> >
> >
> > What do you guys do with your Propanol portions as they come off the still. Are these supposed to be drinkable? Or do they get used as weed killer?
> >
> > I have mine separated and they don'e smell quite like the ethanol that came off. I'm wondering if I should be filtering these along with the ethanol or not.
> >
>


#42304 From: Bob Glicksman <bobg542492@...>
Date: Tue May 1, 2012 4:56 pm
Subject: Re: Re: Higher Alcohols
robertglicksman
Send Email Send Email
 
It does not matter how your reflux is controlled -- LM, VM or CM.  What matters is that you have some means - any means - to control the reflux ratio.  I agree that starting at 100% reflux you bring the column into equilibrium and then the most volitile component will comprise the vapor at the still head.  You can slowly bleed off the foreshots and heads, if you wish, and then monitor the ethanol run until you decide that there is too much lower volitility stuff coming off and stop.

-----Original Message-----
From: White Bear <sha_man_1@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Tue, May 1, 2012 2:41 am
Subject: Re: [new_distillers] Re: Higher Alcohols

 
  It depends on what type of still you are using.  With a pot still, you will NOT be able to remove the Propanol's totally it's just not that efficient.  With much experience it is relatively easy to remove most of them by making cuts by nose and tossing the first 50ml - 100ml per 5gallons.  Things get easier with a reflux still and LM (liquid management) under total reflux.
  As to knowing which layer is Propanol and which is Ethanol - I go by volume and taste.  Through experience, you will develop a "Taste" for the cuts and a nose for the scent of ethanol.  Here I must remind you not to be greedy, if your cuts run into each other so-be-it, it's going to happen.  This will ensure you are getting the finest product that your still will allow.
White Bear

--- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:

From: gavinflett <gavin_flett@...>
Subject: [new_distillers] Re: Higher Alcohols
To: new_distillers@yahoogroups.com
Date: Monday, April 30, 2012, 3:42 PM

 
Thanks White bear.

I looked it up myself and specifically I meant Propanol-2 with a boiling point of 82.5C. So I understand from Wikipedia that this gets separated from the ethanol by adding basically some form of salt. How do I know which layer is the Propanol-2 and which is the Ethanol.

If some Propanol gets in with my ethanol, should I get it out? Can I get it out? How do I do that?

--- In new_distillers@yahoogroups.com, White Bear <sha_man_1@...> wrote:
>
> Gavin-
>   attached is the description of Propanols 1 & 2 from Wikipedia.  I had to look it up myself to be sure the proper identification.
> White Bear
>
> --- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
> From: gavinflett <gavin_flett@...>
> Subject: [new_distillers] Re: Higher Alcohols
> To: new_distillers@yahoogroups.com
> Date: Monday, April 30, 2012, 10:39 AM
>
>
>
>  
>
>
>
> Ok, again there is a mix up in terminology. Forget what I said about higher alcohols, I want to know about the Propanols 1&2, the part that comes of after the ethanol.
>
> --- In new_distillers@yahoogroups.com, White Bear <sha_man_1@> wrote:
> >
> > Gavin-
> >   These "Higher Alcohols" or Fore-shots, are poisonous.  They contain acetone, phenols, methanol and other nasties in proportion to the type and amount of mash made.  They are found in grain and fruit based mashes and are best cut from any of the alcohol collected for re-distillation or use.
> >  
> >   A good use for the fore-shots is to start camp fires, inside a lighter, weed killer etc.  By all means do not drink them.  Be well
> > White Bear
> >
> > --- On Mon, 4/30/12, gavinflett <gavin_flett@> wrote:
> >
> >
> > From: gavinflett <gavin_flett@>
> > Subject: [new_distillers] Higher Alcohols
> > To: new_distillers@yahoogroups.com
> > Date: Monday, April 30, 2012, 12:04 AM
> >
> >
> >
> >  
> >
> >
> >
> > What do you guys do with your Propanol portions as they come off the still. Are these supposed to be drinkable? Or do they get used as weed killer?
> >
> > I have mine separated and they don'e smell quite like the ethanol that came off. I'm wondering if I should be filtering these along with the ethanol or not.
> >
>


#42305 From: "gavinflett" <gavin_flett@...>
Date: Tue May 1, 2012 5:02 pm
Subject: Re: My reflux column
gavinflett
Send Email Send Email
 
Thanks for the great explanation

So you figure it's my condenser huh? How will I know how much bigger to go? I
have used a 1/4" soft copper coil (about 10' worth) and coiled it into a 1.5" X
13" coil. Should I be using 3/8 soft copper coil then? Or can I get a way with
just turning the water up? It make sense in theory what you are saying about the
input of heat energy. But does having a colder condenser really produce more
distillate? The water coming out of the condenser I have now is not warm, it's
fairly cool to the touch (maybe about 10C).

--- In new_distillers@yahoogroups.com, Bob Glicksman <bobg542492@...> wrote:
>
>
>
> Hi Gavin,
>
> If you got higher proof when your column was uninsulated, then I would say
that this is a clear indication that you don't have enough heat removal capacity
in your condenser(s).  Remember conservation of energy -- the energy that goes
into the still must all come out of the still.  However, you can't just radiate
heat arbitrarily out the column wall because the fractionating "magic" that
causes the ethanol and water to separate requires a very specific temperature
gradient to exist up the length of the packing.  If the temperature gradient is
not maintained exactly throughout the run, your column will fall out of
equilibrium and the proof will go down (or the product rate will go down).  I
never fully answered your question about taking heat off of the column walls, so
I will do so below.  But the bottom line is that your condensor(s) is probably
undersized for the heat that you are puting in.
>
> Figuring out the right size for a condensor is a little tough.  I forget the
metric units, but in English units, 1 BTU raises one pound of water one degree
F.  Recall that heat transfer can only take place from a higher temperature to a
lower temperature.  To get azeotrope, the vapor temperature from which you are
removing heat in the condenser(s) is the boiling point of the azeotrope which is
something like 173 deg F.  If you are using cooling water at 73 degrees F to
remove heat in the condenser, then at MOST you will be able to raise the water
temperature 100 degress F (below boiling), therefore absorb 100 BTU of heat for
every pound of water that flows through the condenser.  Convert pounds of water
to liquid volume and you will know the minimum flow rate needed.  If you measure
the input and output coolant temperature from your condenser(s) and the coolant
flow rate, you can calculate the anount of heat energy that you are removing and
compare this with the heat energy that you are puting into the column.  I'll bet
that you don't have enough removal and need a larger condenser(s).
>
> Here is why you must insulate your column.  The fractional distallation
process upon which your still column works requires a constant heat exchange at
various plates running up the column of the still.  You don't have actual plates
with a packed column, but the principle is the same (you have 'theoretical
plates" and the number of theoretical plates that you have depends upon the HETP
of the packing material and the packing height).  Each plate in the column
represents a mixture of ethanol and water that corresponds to a liquid/vapor
equilibrium at some specific concentration of ethanol/water in the mixture.  The
specifics are not arbitrary.  They are absolutely dictated by physics and depend
only upon the initial concentration of ethanol/water in your beer.  If your beer
is, say, 10% ethanol and 90% water (by volume), then physics dictates that the
vapors resulting from boiling this mixture will contain 55% ethanol/45% water,
by volume when condensed back to liquid.  You can't change this -- it is
required by the laws of physics.  So your boiler, which is the first "plate"
will be the the boiling point of a 10% ethanol/90% water mixture, your first
theoretical plate in your column must be at the boiling point of a 55%
ethanol/45% water liquid mixture, the next plate up must be at whatever the
concentration ratio phsycis dictates , etc.  You can compute what physics
dictates from the LHV of water and ethanol and the molar concentration at each
step, or simply find it in a table or graph in a book (sorry, my copy of Nixon
and McCaw is loaned out right now so I can't cite you the page and figure
number, but it is there for sure).  In any event, each plate (real or
theoretical) in your column must be maintained at the specific temperature that
is the boiling point of the mixture at that plate, as required by the physics of
liquid/vapor equilibrium (LVE).  If the column is not held precisely in this
state of equilibirum, your production and proof will change.  So however you do
it, you are required, by the laws of physics, to keep the column in exact
equilibrium.
>
> Now you can see why simply removing insulation won't work.  You have no way of
precisely controlling the heat transfer out of the walls of the column.  Yes,
you will lose heat (which in your case is necessary) but you can't lose it in
precisely the way to maintain the temperature gradient up the packing that is
required to maintain equilibirum.  The temperature and degree of airflow past
the column will change and the heat removed will at best be even up the column
and more generally be determined by air currents and imprefections in the column
wall and will in no way represent what is needed to maintain equilibrium.
>
> Now, it is not impossible to do what you were thinking.  You could insulate
the column really well and put a computer controlled heat exchanger on each
plate (if you had real plates) and control the heat removal on each plate to
keep that plate at the precise temperature that equilibrium requires.  This, in
fact, is exactly what the petrochemical industry does.  An oil refinery is just
a large fractionating column where it is desired to take off product from each
plate -- gasoline has the lowest boiling point, followed by diesel fuel,
kerosine, light lubricating oil, bunker oil, heavy lubricating oil, etc.  The
technology to do this on a small ethanol still is not beyond the reach of an
individual distiller, but the question is:  why would you want to go to all of
this troube if you are only interested in separating ethanol from water?  Some
smart person figured out, a long time ago, that you can maintain still colimn
equilibrium via only one measurement and one control -- by sending some
condensed product back down the still column (reflux).  This is a whole lot
easier and cheaper than physically controlling the temperature of each plate and
it works with continuous packing as well as with discrete plates.  So this is
why reflux is required.
>
> Bob
>
>
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sun, Apr 29, 2012 11:24 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> Hi Bob, thanks for the attention on this. Answers are below each question in
red
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Mon, 30 Apr 2012 02:02:10 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> Here are a few suggestions, Gavin:
>
> 1.  Check that everything is as it should be.  Is your column well insulated? 
Is the packing clean and the vors running freely through it?  Is the still
running at atmospheric pressure (no pressure buildup, e.g. due to clogged
packing)? Yes the column is well insulated. But I got my 93% when it wasn't
insulated. After I put up the insulation, the reflux seems to stop and the ABV
drops into the 80's.
>
> 2.  Make sure that your temperature probe is measuring only vapor and only
above the packing. Yes
>
> 3.  Is temperature your sole detemrination of proof or have you checked this
with a hydrometer? Yes  If the latter, do you compenate the hydometer reading
for the temperature? It's read at the correct temp of 20C
>
> 4.  Have you checked to make sure that your temperature probe is reading
accurately?  No Try testing it in boiling water and make sure to adjust the
boiling point for altitude if you are not near sea level. I'm at sea level
>
> 5.  Make sure (as best that you can determine) that the vapors ascend through
the packing evenly and that reflux runs down the center of the column and not
down th walls of the column. How am I supposed to do that? I can't see inside
the still. I have the column packed with copper mesh, I have no idea if it's
allowing the vapours to travel through evenly. I can breath through the column,
which I read was a way to determine the packing density.
>
> 6.  After clearing the above, do what Nixon and McCaw recommend and run at
100% reflux ratio (all product gets poured back down the center of the column). 
Wait for the column to reestablish equilibrium and see what your
proof/temperature is.  If the proof is not at azeotrope, then you either (a)
have too much heat going in and the vapors are ascending through the packing too
fast, reducing its real HETP, or (c) you do not have enough cooling capacity in
your condensors and you can't get get the heat back out even with your reduced
heat input, or (c) your packing HETP is too low.  If you get to this step
without a resolution, please post the details of your still and lets run through
some numbers: I managed to get at the most 93% ABV, but only for a short while,
after that I had to increase the power to the still just so it wouldn't take 3
days to distill everything. My still charge was about 20 L at 40%. So far it's
been going for 15 hours and it's still reading 80.5-82C (which I think is
slightly inaccurate as the still ran steady at about 77C for about 8 hours).
>
> - boiler heat (what you are running at).
> - proof of the beer (and how did you determine this?).
> - column height and packing material.
> - column diameter.
> - still head configuration and reflux configuration (CM, LM, VM)
> - how many condensers and where are they located
> - what are you running through the condensors (water, beer, other) and at what
temperature.  Do you have a way to measure coolant flow rate through the
condensors and what is it?
>
> There isn't a whole lot more to this.  A basic batch reflux column still that
is well insulated from heat loss only has a few relevant variables to work with:
> - proof of the beer
> - heat input, which in conjunction with column diameter determines the vapor
flow rate up the column (which can't be too fast or your HETP will be a lot
lower than you think it is).
> - heat output, which MUST balnace heat input and if you can't remove enough
heat via the condensors, will limit the proof that you can get.
> - column height and HETP of the packing, which, in conjunction with reflux
ratio and heat removal, determines the proof of the product.
> - measurement technique (which, if in error, will mislead you).
>
> KR,
> Bob
>
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 8:46 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> Lowering the power did not seem to make a difference. I am now collecting the
distillate at about 87%. Maybe it's just near the end of the run, but the temp
still reads 79C.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 23:20:24 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> Please let us know how turning down the heat turned out.  As to your question
about reflux, the answer depends upon what type of reflux management system you
use.  Collant management (CM) systems generally require a greater flow rate of
cooling water (or whatever you use for coolant).  Cooling the water will help,
but you will achieve greater results by upping the flow rate.  Liquid Management
(LM) and Vapor Management(VM) systems have a value that controls how much liquid
or vapor is taken off as product; the restis reflux.  So you take less product
to increase the reflux ratio.
>
> I suggest that you get a copy of Nixon and McCaw from The Amphora Society
website.  The book is excellent and after you read and digest it all, it will
save you countless hours of experimentation and wrong turns.
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 6:30 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> You definitely talk good sense mister.
>
>
> Yes, I did think that more heat would equal more product coming out. And I did
know that it has to be counteracted with more reflux, I was just unsure of how
that could be done (do I pump more water through, thus making the water colder).
I am still unsure of why insulating the column is better, wouldn't more reflux
happen if the column is air cooled all the way up (vapours are cooling,
condensing and revapourizing more times)?
>
>
> I turned down the heat to the point where the output is around a KW, hopefully
this will produce a purer spirit.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 20:39:43 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> This is just a guess, Gavin, but I'd say that you are puting in too much heat,
and/or not providing enough reflux and/or enough heat removal in your condenser.
Distillation is driven by basic physics -- whatever heat you put in must be
taken out.  Follow this analysis along, if you will:
>
> The latent heat of vaporization (LHV) is the heat energy that you must put
into a liquid at its boiling pint in order to vaporize it.  Conversely, in order
to liquify a vapor at the dew point, you need to remove the LHV.  When you have
a mixture of two substances in a liquid, each substance retains its individual
physical and chemical characteristics, including its LHV.  The LHV is an
intrinsic physical property of any substance and it turns out that the LHV of
ethanol, on a volume basis (not on a mole basis) is considerably lower than the
LHV for a similar volume of water.  Thus, if you boil off a beer that is 10%
ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water
(a point on the co-called "VLE" curve that you see all over the place when
discussing distillation).
>
> Now, your packed column performs some fractionating "magic" such that the
vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol
and 4% water.  But given the information above, it should be obvious that if you
vaporize off a quart of beer and want to get out a quart of azeotropic ethanol,
the energy that you remove will be less than the energy that you put in.  Since
the still column does not otherwise lose energy (it is well insulated) and does
not have a means to store energy, then this can't work - conservation of energy
says it can't work.  So what will happen if you try and remove all of the vapor
at the top of the column as product is that the proof MUST go down to the same
55% ethanol 45% water that you put in (for this example).  This is why you MUST
HAVE REFLUX.  The only way to get a product at or near azeotrope is to send a
significant amount of condensed product back down the column so that it is
recycled enough times to remove all of the heat that physics says must be
removed.
>
> This is all covered well in Nixon and McCaw "The Compleat Distiller".  The
more heat that you put into your still, the more heat that your condensor must
remove, so if the condensor design is inadequate, you can't get high proof even
with 100% reflux ratio.  If you have enough heat removal capacity in your
condensor, you must still set your reflux ratio high enough remove the LHV using
the azeotrope.  You require a minimum reflux ratio if you have enough packing,
but your HETP may be too low, in which case you can compensate, but only by
increasing the reflux ratio.  If 100% reflux (no product takeoff) won't get the
proof up high enough (as indicated by the temperature of the vapors at the top
of the column) than you either must reduce the heat input to the still or
increase the heat removal (bigger or faster condensor).
>
> Lastly, Nixon and McCaw also make that point that too much heat can cause the
vapor to travel up the column too fast, negating the fractionating "magic" that
happens in the column packing.
>
> A 2" diameter column will be driven quite well by a 1 KW heater.  1.6 KW is
much more than you need.  Too much heat is BAD -- it does not make distillation
faster, as you might intuitively assume.  It only requires you to have more
packing HETP, higher reflux ratio, and more condenser capacity or else the proof
will go down, as you have already found out the hard way.
>
> Bob
>
>
>
> -----Original Message-----
> From: gavinflett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 4:35 pm
> Subject: [new_distillers] My reflux column
>
>
>
>
>
> Ok guys, I need to get some reflux column experts to weigh in on this one. I
built an offset reflux head. It's about 6' tall and 2" thick. I'm using an
electric hotplate that puts out up to 1600W. I'm also doing this outside and
it'a bit chilly at 11C, but I have the whole thing insulated including the
column.
>
> Now.... i'm only getting about 90% out this thing right now. It's been going
for 8 hours now and have only collected about 3 or 4L. The most I got out this
thing was 93%.
>
> My question is, why can't I get 96% (or whatever the maximum is) out of this
thing? Why is it coming out so slow, and why isn't it more potent?
>

#42306 From: Bob Glicksman <bobg542492@...>
Date: Tue May 1, 2012 6:03 pm
Subject: Re: Re: My reflux column
robertglicksman
Send Email Send Email
 
Gavin,
 
What matters is how much heat your condenser is absorbing.  A low output coolant temperature may simply mean that there isn't enough heat exchange in the condenser to heat up the cooling water; it does not have to mean that there is more than enough heat exchange (but I could mean this as well).  As discussed previously, you must remove the LHV from the column - physics demands this.  If you don't remove it via reflux and its associated heat exchange, the column will continue to heat up until the product is the same proof as the vapors that came off of your boiler, thus guaranteeing that the product removes the LHV, as conservation of energy demands.  If you have some heat removal from your condenser but not enough, you will get some intermediate proof product.  Its all about conservation of energy.
 
This being said, it is rather complicated to try and compute the design of a condenser system.  You have to know a lot more than I do about the heat conductivity of the tubing and of the heat transfer capacity of the cooling medium.  But you already have a condenser, so you can measure what it is doing, as follows:
 
1.  Take the temperature of the cooling water before it enters the condenser.
2.  Take the temperature of the cooling water after it leaves the condenser.
3.  Measure the coolent flow rate through the condenser (just collect some of the output for a few, carefully timed minutes, and measure how much that is, e.g. in liters, to determine the flow rate of liters/minute).
 
Now you know the temperature change and the mass flow rate.  You can look up the definition of a unit of heat energy on the Internet, e.g. a Calorie or BTU, defined as a certain
number of degrees of temperature change over a certain mass.  You can look up the weight (mass) of your coolent (water, I assume) to convert your volume measurement to weight (mass) measurement.  Doing this will ultimately give you the amount of energy that your condenser is actually transferring out per unit of time.  Whatever units you use (joules per minute, BTUs per hour, etc.) can be converted to electrical power units of KW.  You then compare this calculated value of heat transfer (power) of the condenser with your input power and see if the latter exceeds the former.  If it does, you need a bigger condenser, which likely means more tubing - either in length or in diameter, or tubing with a better thermal conduction.  Knowing what your current condeser actually does will at least tell you how much more of the same you need.
 
This analysis is only approximate, as heat transfer is temperature dependent and the definition of a calorie or BTU is at some specific temperature.  But it ought to be good enough to figure out if the problem is in the condenser or somewhere else.  Note that there is no harm whatsoever in having too much heat transfer capability in your condenser.  If it removes more than the LHV, then it will also remove "sensible heat" of the resulting liquid product/reflux meaning that the condensed liquid will be cooler than its dew point.  That's OK, as you are adjusting the reflux ratio to keep the column in equilibrium anyway, so this only impacts the actual setting of your reflux ratio adjustment.
 
There are other reasons for low proof of product -- inadequate reflux, too low a HETP, too much vapor volume into the column (vapors ascent too fast reducing the real HETP of the packing), heat loss from the column walls that distorts the necessary temperature gradient up the column, reflux condensing on the column walls and not flowing down through the center of the column and evenly over the packing, clogs in the packing so that vapor/liquid interaction is contrained (reducing HETP), inaccurate temperature reading,... and probably a whole lot more.  So here is a more complete (I'm sure not comprehensive) checklist:
 
- is your heat input matched to your column diameter so that vapors flow up the column at the recommended rate?
- is your heat removal (condenser) adequate to remove the LHV that you put into the column at the product proof that you desire?
- is the hetp of the packing and height of the packed part of the column sufficient for the proof that you are trying to achieve?
- is your column well insulated, so that heat loss from the walls does not alter the temperature gradient necessary to achieve the desired distillation?
- is the vapor flow through the packing even and is the liquid reflux flow equally even so that vapor and liquid exchange heat efficiently?  This isn't easy to observe unless you have a glass still, but the packing must be clean and free of clogging material and scrubbers must NOT be compressed.
- is your product thermometer measuring the temperature of the vapor only and not of liquid reflux?  (Recall from above that the reflux can be cooler than the dew point; thus you may think that you are getting azeotrope from a thermometer reading and not actually get that proof in the product). 
- is your thermometer losing heat and giving an incorrect rewading?
- is your thermometer well calibrated and accurate enough for you to use it to control the reflux?  (This is not a trival question.  You said that your product vapors were at 79 degrees C indicating 87%; azeotrope, 95.6%, is 78.1 degrees C -- less than one degree C difference.  Take care not to confuse the resolution of a digital thermometer with the accuracy of the thermometer.  A cheap digital thermometer may read out on 0.1 degree C increments but may only be accurate to +/- 2 degrees C).
 
The first two items are what we have been talking about here.  The other items should be reviewed as well.  The point here is that once you understand how the reflux column still works, there are only a limited number of factors that impact the still's ability to provide the desired proof product.
 
Bob

 
-----Original Message-----
From: gavinflett <gavin_flett@...>
To: new_distillers <new_distillers@yahoogroups.com>
Sent: Tue, May 1, 2012 10:02 am
Subject: [new_distillers] Re: My reflux column

 
Thanks for the great explanation

So you figure it's my condenser huh? How will I know how much bigger to go? I have used a 1/4" soft copper coil (about 10' worth) and coiled it into a 1.5" X 13" coil. Should I be using 3/8 soft copper coil then? Or can I get a way with just turning the water up? It make sense in theory what you are saying about the input of heat energy. But does having a colder condenser really produce more distillate? The water coming out of the condenser I have now is not warm, it's fairly cool to the touch (maybe about 10C).

--- In new_distillers@yahoogroups.com, Bob Glicksman <bobg542492@...> wrote:
>
>
>
> Hi Gavin,
>
> If you got higher proof when your column was uninsulated, then I would say that this is a clear indication that you don't have enough heat removal capacity in your condenser(s). Remember conservation of energy -- the energy that goes into the still must all come out of the still. However, you can't just radiate heat arbitrarily out the column wall because the fractionating "magic" that causes the ethanol and water to separate requires a very specific temperature gradient to exist up the length of the packing. If the temperature gradient is not maintained exactly throughout the run, your column will fall out of equilibrium and the proof will go down (or the product rate will go down). I never fully answered your question about taking heat off of the column walls, so I will do so below. But the bottom line is that your condensor(s) is probably undersized for the heat that you are puting in.
>
> Figuring out the right size for a condensor is a little tough. I forget the metric units, but in English units, 1 BTU raises one pound of water one degree F. Recall that heat transfer can only take place from a higher temperature to a lower temperature. To get azeotrope, the vapor temperature from which you are removing heat in the condenser(s) is the boiling point of the azeotrope which is something like 173 deg F. If you are using cooling water at 73 degrees F to remove heat in the condenser, then at MOST you will be able to raise the water temperature 100 degress F (below boiling), therefore absorb 100 BTU of heat for every pound of water that flows through the condenser. Convert pounds of water to liquid volume and you will know the minimum flow rate needed. If you measure the input and output coolant temperature from your condenser(s) and the coolant flow rate, you can calculate the anount of heat energy that you are removing and compare this with the heat ene rgy that you are puting into the column. I'll bet that you don't have enough removal and need a larger condenser(s).
>
> Here is why you must insulate your column. The fractional distallation process upon which your still column works requires a constant heat exchange at various plates running up the column of the still. You don't have actual plates with a packed column, but the principle is the same (you have 'theoretical plates" and the number of theoretical plates that you have depends upon the HETP of the packing material and the packing height). Each plate in the column represents a mixture of ethanol and water that corresponds to a liquid/vapor equilibrium at some specific concentration of ethanol/water in the mixture. The specifics are not arbitrary. They are absolutely dictated by physics and depend only upon the initial concentration of ethanol/water in your beer. If your beer is, say, 10% ethanol and 90% water (by volume), then physics dictates that the vapors resulting from boiling this mixture will contain 55% ethanol/45% water, by volume when condensed back to liqui d. You can't change this -- it is required by the laws of physics. So your boiler, which is the first "plate" will be the the boiling point of a 10% ethanol/90% water mixture, your first theoretical plate in your column must be at the boiling point of a 55% ethanol/45% water liquid mixture, the next plate up must be at whatever the concentration ratio phsycis dictates , etc. You can compute what physics dictates from the LHV of water and ethanol and the molar concentration at each step, or simply find it in a table or graph in a book (sorry, my copy of Nixon and McCaw is loaned out right now so I can't cite you the page and figure number, but it is there for sure). In any event, each plate (real or theoretical) in your column must be maintained at the specific temperature that is the boiling point of the mixture at that plate, as required by the physics of liquid/vapor equilibrium (LVE). If the column is not held precisely in this state of equilibirum, your pr oduction and proof will change. So however you do it, you are required, by the laws of physics, to keep the column in exact equilibrium.
>
> Now you can see why simply removing insulation won't work. You have no way of precisely controlling the heat transfer out of the walls of the column. Yes, you will lose heat (which in your case is necessary) but you can't lose it in precisely the way to maintain the temperature gradient up the packing that is required to maintain equilibirum. The temperature and degree of airflow past the column will change and the heat removed will at best be even up the column and more generally be determined by air currents and imprefections in the column wall and will in no way represent what is needed to maintain equilibrium.
>
> Now, it is not impossible to do what you were thinking. You could insulate the column really well and put a computer controlled heat exchanger on each plate (if you had real plates) and control the heat removal on each plate to keep that plate at the precise temperature that equilibrium requires. This, in fact, is exactly what the petrochemical industry does. An oil refinery is just a large fractionating column where it is desired to take off product from each plate -- gasoline has the lowest boiling point, followed by diesel fuel, kerosine, light lubricating oil, bunker oil, heavy lubricating oil, etc. The technology to do this on a small ethanol still is not beyond the reach of an individual distiller, but the question is: why would you want to go to all of this troube if you are only interested in separating ethanol from water? Some smart person figured out, a long time ago, that you can maintain still colimn equilibrium via only one measurement and one control -- by sending some condensed product back down the still column (reflux). This is a whole lot easier and cheaper than physically controlling the temperature of each plate and it works with continuous packing as well as with discrete plates. So this is why reflux is required.
>
> Bob
>
>
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sun, Apr 29, 2012 11:24 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> Hi Bob, thanks for the attention on this. Answers are below each question in red
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Mon, 30 Apr 2012 02:02:10 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> Here are a few suggestions, Gavin:
>
> 1. Check that everything is as it should be. Is your column well insulated? Is the packing clean and the vors running freely through it? Is the still running at atmospheric pressure (no pressure buildup, e.g. due to clogged packing)? Yes the column is well insulated. But I got my 93% when it wasn't insulated. After I put up the insulation, the reflux seems to stop and the ABV drops into the 80's.
>
> 2. Make sure that your temperature probe is measuring only vapor and only above the packing. Yes
>
> 3. Is temperature your sole detemrination of proof or have you checked this with a hydrometer? Yes If the latter, do you compenate the hydometer reading for the temperature? It's read at the correct temp of 20C
>
> 4. Have you checked to make sure that your temperature probe is reading accurately? No Try testing it in boiling water and make sure to adjust the boiling point for altitude if you are not near sea level. I'm at sea level
>
> 5. Make sure (as best that you can determine) that the vapors ascend through the packing evenly and that reflux runs down the center of the column and not down th walls of the column. How am I supposed to do that? I can't see inside the still. I have the column packed with copper mesh, I have no idea if it's allowing the vapours to travel through evenly. I can breath through the column, which I read was a way to determine the packing density.
>
> 6. After clearing the above, do what Nixon and McCaw recommend and run at 100% reflux ratio (all product gets poured back down the center of the column). Wait for the column to reestablish equilibrium and see what your proof/temperature is. If the proof is not at azeotrope, then you either (a) have too much heat going in and the vapors are ascending through the packing too fast, reducing its real HETP, or (c) you do not have enough cooling capacity in your condensors and you can't get get the heat back out even with your reduced heat input, or (c) your packing HETP is too low. If you get to this step without a resolution, please post the details of your still and lets run through some numbers: I managed to get at the most 93% ABV, but only for a short while, after that I had to increase the power to the still just so it wouldn't take 3 days to distill everything. My still charge was about 20 L at 40%. So far it's been going for 15 hours and it's still reading 80.5-82 C (which I think is slightly inaccurate as the still ran steady at about 77C for about 8 hours).
>
> - boiler heat (what you are running at).
> - proof of the beer (and how did you determine this?).
> - column height and packing material.
> - column diameter.
> - still head configuration and reflux configuration (CM, LM, VM)
> - how many condensers and where are they located
> - what are you running through the condensors (water, beer, other) and at what temperature. Do you have a way to measure coolant flow rate through the condensors and what is it?
>
> There isn't a whole lot more to this. A basic batch reflux column still that is well insulated from heat loss only has a few relevant variables to work with:
> - proof of the beer
> - heat input, which in conjunction with column diameter determines the vapor flow rate up the column (which can't be too fast or your HETP will be a lot lower than you think it is).
> - heat output, which MUST balnace heat input and if you can't remove enough heat via the condensors, will limit the proof that you can get.
> - column height and HETP of the packing, which, in conjunction with reflux ratio and heat removal, determines the proof of the product.
> - measurement technique (which, if in error, will mislead you).
>
> KR,
> Bob
>
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 8:46 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> Lowering the power did not seem to make a difference. I am now collecting the distillate at about 87%. Maybe it's just near the end of the run, but the temp still reads 79C.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 23:20:24 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> Please let us know how turning down the heat turned out. As to your question about reflux, the answer depends upon what type of reflux management system you use. Collant management (CM) systems generally require a greater flow rate of cooling water (or whatever you use for coolant). Cooling the water will help, but you will achieve greater results by upping the flow rate. Liquid Management (LM) and Vapor Management(VM) systems have a value that controls how much liquid or vapor is taken off as product; the restis reflux. So you take less product to increase the reflux ratio.
>
> I suggest that you get a copy of Nixon and McCaw from The Amphora Society website. The book is excellent and after you read and digest it all, it will save you countless hours of experimentation and wrong turns.
>
>
>
> -----Original Message-----
> From: Gavin Flett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 6:30 pm
> Subject: RE: [new_distillers] My reflux column
>
>
>
>
>
> You definitely talk good sense mister.
>
>
> Yes, I did think that more heat would equal more product coming out. And I did know that it has to be counteracted with more reflux, I was just unsure of how that could be done (do I pump more water through, thus making the water colder). I am still unsure of why insulating the column is better, wouldn't more reflux happen if the column is air cooled all the way up (vapours are cooling, condensing and revapourizing more times)?
>
>
> I turned down the heat to the point where the output is around a KW, hopefully this will produce a purer spirit.
>
>
>
> To: new_distillers@yahoogroups.com
> From: bobg542492@...
> Date: Sat, 28 Apr 2012 20:39:43 -0400
> Subject: Re: [new_distillers] My reflux column
>
>
>
>
>
> This is just a guess, Gavin, but I'd say that you are puting in too much heat, and/or not providing enough reflux and/or enough heat removal in your condenser. Distillation is driven by basic physics -- whatever heat you put in must be taken out. Follow this analysis along, if you will:
>
> The latent heat of vaporization (LHV) is the heat energy that you must put into a liquid at its boiling pint in order to vaporize it. Conversely, in order to liquify a vapor at the dew point, you need to remove the LHV. When you have a mixture of two substances in a liquid, each substance retains its individual physical and chemical characteristics, including its LHV. The LHV is an intrinsic physical property of any substance and it turns out that the LHV of ethanol, on a volume basis (not on a mole basis) is considerably lower than the LHV for a similar volume of water. Thus, if you boil off a beer that is 10% ethanol and 90% water, you get a vapor that is about 55% ethanol and 45% water (a point on the co-called "VLE" curve that you see all over the place when discussing distillation).
>
> Now, your packed column performs some fractionating "magic" such that the vapor at the top of the column should be azepropic ethanol - i.e. 96% ethanol and 4% water. But given the information above, it should be obvious that if you vaporize off a quart of beer and want to get out a quart of azeotropic ethanol, the energy that you remove will be less than the energy that you put in. Since the still column does not otherwise lose energy (it is well insulated) and does not have a means to store energy, then this can't work - conservation of energy says it can't work. So what will happen if you try and remove all of the vapor at the top of the column as product is that the proof MUST go down to the same 55% ethanol 45% water that you put in (for this example). This is why you MUST HAVE REFLUX. The only way to get a product at or near azeotrope is to send a significant amount of condensed product back down the column so that it is recycled enough times to remov e all of the heat that physics says must be removed.
>
> This is all covered well in Nixon and McCaw "The Compleat Distiller". The more heat that you put into your still, the more heat that your condensor must remove, so if the condensor design is inadequate, you can't get high proof even with 100% reflux ratio. If you have enough heat removal capacity in your condensor, you must still set your reflux ratio high enough remove the LHV using the azeotrope. You require a minimum reflux ratio if you have enough packing, but your HETP may be too low, in which case you can compensate, but only by increasing the reflux ratio. If 100% reflux (no product takeoff) won't get the proof up high enough (as indicated by the temperature of the vapors at the top of the column) than you either must reduce the heat input to the still or increase the heat removal (bigger or faster condensor).
>
> Lastly, Nixon and McCaw also make that point that too much heat can cause the vapor to travel up the column too fast, negating the fractionating "magic" that happens in the column packing.
>
> A 2" diameter column will be driven quite well by a 1 KW heater. 1.6 KW is much more than you need. Too much heat is BAD -- it does not make distillation faster, as you might intuitively assume. It only requires you to have more packing HETP, higher reflux ratio, and more condenser capacity or else the proof will go down, as you have already found out the hard way.
>
> Bob
>
>
>
> -----Original Message-----
> From: gavinflett <gavin_flett@...>
> To: new_distillers <new_distillers@yahoogroups.com>
> Sent: Sat, Apr 28, 2012 4:35 pm
> Subject: [new_distillers] My reflux column
>
>
>
>
>
> Ok guys, I need to get some reflux column experts to weigh in on this one. I built an offset reflux head. It's about 6' tall and 2" thick. I'm using an electric hotplate that puts out up to 1600W. I'm also doing this outside and it'a bit chilly at 11C, but I have the whole thing insulated including the column.
>
> Now.... i'm only getting about 90% out this thing right now. It's been going for 8 hours now and have only collected about 3 or 4L. The most I got out this thing was 93%.
>
> My question is, why can't I get 96% (or whatever the maximum is) out of this thing? Why is it coming out so slow, and why isn't it more potent?
>


#42307 From: "David Eastham" <planetgong0@...>
Date: Tue May 1, 2012 6:19 pm
Subject: Re: My reflux column
planetgong0
Send Email Send Email
 
I had a similar problem with purity, turning the heat down and down to see what
happened, till eventually nothing came out the column. I found that increasing
the heat actually gave me a purer product. I think what was happening at a
certain temperature the column was acting only as a fractionating column not a
reflux. All or most of the distillate at the top of the column was being taken
off before any reflux was taking place. The cooling water was only tepid. When I
increased the heat I then got the reflux I was after and the purity went up. The
temperature of the cooling water also went up to 50-60c. It is a fine balancing
act, but as your cooling water is not warm the condenser may not be getting the
hot vapours?
Regards
Dave E



--- In new_distillers@yahoogroups.com, "gavinflett" <gavin_flett@...> wrote:
>
> Thanks for the great explanation
>
> So you figure it's my condenser huh? How will I know how much bigger to go? I
have used a 1/4" soft copper coil (about 10' worth) and coiled it into a 1.5" X
13" coil. Should I be using 3/8 soft copper coil then? Or can I get a way with
just turning the water up? It make sense in theory what you are saying about the
input of heat energy. But does having a colder condenser really produce more
distillate? The water coming out of the condenser I have now is not warm, it's
fairly cool to the touch (maybe about 10C).
>
> ---
> >
>

#42308 From: Gavin Flett <gavin_flett@...>
Date: Tue May 1, 2012 6:25 pm
Subject: RE: Re: My reflux column
gavinflett
Send Email Send Email
 
Good guess, but the condenser is getting the vapours, I can feel the heat around the pipe containing the condenser near the bottom, and near the top it gets cooler to the touch. I'll try a couple of things then see what the issue was


To: new_distillers@yahoogroups.com
From: planetgong0@...
Date: Tue, 1 May 2012 18:19:05 +0000
Subject: [new_distillers] Re: My reflux column

 
I had a similar problem with purity, turning the heat down and down to see what happened, till eventually nothing came out the column. I found that increasing the heat actually gave me a purer product. I think what was happening at a certain temperature the column was acting only as a fractionating column not a reflux. All or most of the distillate at the top of the column was being taken off before any reflux was taking place. The cooling water was only tepid. When I increased the heat I then got the reflux I was after and the purity went up. The temperature of the cooling water also went up to 50-60c. It is a fine balancing act, but as your cooling water is not warm the condenser may not be getting the hot vapours?
Regards
Dave E

--- In new_distillers@yahoogroups.com, "gavinflett" <gavin_flett@...> wrote:
>
> Thanks for the great explanation
>
> So you figure it's my condenser huh? How will I know how much bigger to go? I have used a 1/4" soft copper coil (about 10' worth) and coiled it into a 1.5" X 13" coil. Should I be using 3/8 soft copper coil then? Or can I get a way with just turning the water up? It make sense in theory what you are saying about the input of heat energy. But does having a colder condenser really produce more distillate? The water coming out of the condenser I have now is not warm, it's fairly cool to the touch (maybe about 10C).
>
> ---
> >
>



#42309 From: "David Eastham" <planetgong0@...>
Date: Tue May 1, 2012 7:20 pm
Subject: Re: My reflux column
planetgong0
Send Email Send Email
 
I'd definitely try turning the heat up a bit, get more product refluxing, my
condenser is too hot to touch half way up, and only gets bearable to touch about
an inch from the top. I check no vapours are coming out the top by smell and a
cold water glass bottle placed at the vent now and then (check for condensate).
I run at 1100-1300 watts (15l wash)and my condenser is only 6 inch, and my
column 4ft packed with copper mesh. I let run 100% reflux for 1hr then take off
at 600ml per hour, 94-95% every time. No vapours come out the top of the column.
Good luck whatever you decide, I am no expert just telling you what worked for
me.
Regards
Dave E

--- In new_distillers@yahoogroups.com, Gavin Flett <gavin_flett@...> wrote:
>
>
> Good guess, but the condenser is getting the vapours, I can feel the heat
around the pipe containing the condenser near the bottom, and near the top it
gets cooler to the touch. I'll try a couple of things then see what the issue
was
>
> To: new_distillers@yahoogroups.com
> From: planetgong0@...
> Date: Tue, 1 May 2012 18:19:05 +0000
> Subject: [new_distillers] Re: My reflux column
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>       I had a similar problem with purity, turning the heat down and down to
see what happened, till eventually nothing came out the column. I found that
increasing the heat actually gave me a purer product. I think what was happening
at a certain temperature the column was acting only as a fractionating column
not a reflux. All or most of the distillate at the top of the column was being
taken off before any reflux was taking place. The cooling water was only tepid.
When I increased the heat I then got the reflux I was after and the purity went
up. The temperature of the cooling water also went up to 50-60c. It is a fine
balancing act, but as your cooling water is not warm the condenser may not be
getting the hot vapours?
>
> Regards
>
> Dave E
>
>
>
> --- In new_distillers@yahoogroups.com, "gavinflett" <gavin_flett@> wrote:
>
> >
>
> > Thanks for the great explanation
>
> >
>
> > So you figure it's my condenser huh? How will I know how much bigger to go?
I have used a 1/4" soft copper coil (about 10' worth) and coiled it into a 1.5"
X 13" coil. Should I be using 3/8 soft copper coil then? Or can I get a way with
just turning the water up? It make sense in theory what you are saying about the
input of heat energy. But does having a colder condenser really produce more
distillate? The water coming out of the condenser I have now is not warm, it's
fairly cool to the touch (maybe about 10C).
>
> >
>
> > ---
>
> > >
>
> >
>

#42310 From: Jason Schnapp <spdjnky_42@...>
Date: Mon Apr 30, 2012 5:14 pm
Subject: Re: Higher Alcohols
spdjnky_42
Send Email Send Email
 
+1 use them for anything you would use acetone or white gas for

Sent via my Samsung Galaxy Prevail from Boost Mobile

White Bear <sha_man_1@...> wrote:

>Gavin-
>  These "Higher Alcohols" or Fore-shots, are poisonous.  They contain
acetone, phenols, methanol and other nasties in proportion to the type and
amount of mash made.  They are found in grain and fruit based mashes and are
best cut from any of the alcohol collected for re-distillation or use.
> 
>  A good use for the fore-shots is to start camp fires, inside a lighter, weed
killer etc.  By all means do not drink them.  Be well
>White Bear
>
>--- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
>From: gavinflett <gavin_flett@...>
>Subject: [new_distillers] Higher Alcohols
>To: new_distillers@yahoogroups.com
>Date: Monday, April 30, 2012, 12:04 AM
>
>
>
> 
>
>
>
>What do you guys do with your Propanol portions as they come off the still. Are
these supposed to be drinkable? Or do they get used as weed killer?
>
>I have mine separated and they don'e smell quite like the ethanol that came
off. I'm wondering if I should be filtering these along with the ethanol or not.
>
>
>
>
>
>

#42311 From: Jason Schnapp <spdjnky_42@...>
Date: Mon Apr 30, 2012 7:01 pm
Subject: Re: Re: Higher Alcohols
spdjnky_42
Send Email Send Email
 
Anything after hearts is tails. You can collect on a reflux run to about 40%. these will have bad odor and taste. You can recycle these into the next wash or toss them in the trash.


From: gavinflett <gavin_flett@...>
To: new_distillers@yahoogroups.com
Sent: Monday, April 30, 2012 10:39 AM
Subject: [new_distillers] Re: Higher Alcohols

 
Ok, again there is a mix up in terminology. Forget what I said about higher alcohols, I want to know about the Propanols 1&2, the part that comes of after the ethanol.

--- In new_distillers@yahoogroups.com, White Bear <sha_man_1@...> wrote:
>
> Gavin-
>   These "Higher Alcohols" or Fore-shots, are poisonous.  They contain acetone, phenols, methanol and other nasties in proportion to the type and amount of mash made.  They are found in grain and fruit based mashes and are best cut from any of the alcohol collected for re-distillation or use.
>  
>   A good use for the fore-shots is to start camp fires, inside a lighter, weed killer etc.  By all means do not drink them.  Be well
> White Bear
>
> --- On Mon, 4/30/12, gavinflett <gavin_flett@...> wrote:
>
>
> From: gavinflett <gavin_flett@...>
> Subject: [new_distillers] Higher Alcohols
> To: new_distillers@yahoogroups.com
> Date: Monday, April 30, 2012, 12:04 AM
>
>
>
>  
>
>
>
> What do you guys do with your Propanol portions as they come off the still. Are these supposed to be drinkable? Or do they get used as weed killer?
>
> I have mine separated and they don'e smell quite like the ethanol that came off. I'm wondering if I should be filtering these along with the ethanol or not.
>




#42312 From: "tim.2ndamendment" <tim.2ndamendment@...>
Date: Mon Apr 30, 2012 7:46 pm
Subject: i'm looking for suggestions
tim.2ndamend...
Send Email Send Email
 
I have recently decided that I am going to follow in my grandfather's footsteps
and start distilling at home, the only problem is that he passed away last year
and he never told me how to make what I consider the best Irish whiskey I've
ever tasted, or how to build a still for that matter. The research i've done
seems to make it look very complicated and expensive to get started. Does anyone
have any suggestions on how I can begin to try and duplicate that old family
recipe?

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