crazy? or possible.. 3 x bubble plates side by side

[Silk City Distillers]

One technique to keep up your sleeve is to use your 12 plate to clean up heads in a third distillation, but you need a clean clean still to do it.

What I mean by that is, load your kettle with your semi-finished vodka.  Run as high reflux ratio is possible.  Take a slow finishing heads cut, then stop.  Drain your plates (or not) and let your kettle cool.  Drain your finished product from the kettle.  Ideally, through a heat exchanger to cool it down.  I’ve played around with this approach to clean up neutral without the time and energy of putting it all through, it does work, and the approach is similar to some of the continuous gns redistillation rigs you see on the market.

[Alex_Sor]

Do you have a lot of extra time?
for the third and fourth slow distillation?
Can it be easier to do just one run under vacuum?
I do not understand such advice - "do everything slowly and for a long time".

[Silk City Distillers]

Don’t pull vacuum on any still not specifically designed for vacuum operation.

 

 

[needmorstuff]

18 hours ago, Silk City Distillers said:

One technique to keep up your sleeve is to use your 12 plate to clean up heads in a third distillation, but you need a clean clean still to do it.

What I mean by that is, load your kettle with your semi-finished vodka.  Run as high reflux ratio is possible.  Take a slow finishing heads cut, then stop.  Drain your plates (or not) and let your kettle cool.  Drain your finished product from the kettle.  Ideally, through a heat exchanger to cool it down.  I’ve played around with this approach to clean up neutral without the time and energy of putting it all through, it does work, and the approach is similar to some of the continuous gns redistillation rigs you see on the market.

so, what I actually have is a 4 plate bubble column, i was debating the idea of trying to get dye to retrofit it out to 12 plates across 3 columns, that will be 14,000 USD and likely not even ideal. I am thinking the way to go is just leave that still alone, use it for stripping runs, either pot still mode or with the 4 plates. (and of course to make my other spirits gin/rum)

Then take the output of that to the 100l still and run it through a column full of SPP, maybe with a bubble plate or a torpedo at the bottom of the column.

This sounds to me the easiest, least expensive option with a good chance of a success. (maybe 5k usd)

My question is - 4" or 3" column for a 100l still and roughly 2m of room about the boiler, and with that choice how much power.

I am leaning toward the 4" and 5kw.. but as always there are smarter people than myself in the room so would love feedback.

13 hours ago, Silk City Distillers said:

Don’t pull vacuum on any still not specifically designed for vacuum operation.

 

 

lol I know right 😉

[adamOVD]

@alex_sor So you're telling us you like vacuum stills?

I have 80" of reflux with a 4" column, and staying above 190 is a balancing act. I have not tried SPP though. If it was me id try 3" first. At that size you could always sell it. If you build it yourself, even come out ahead.  

[needmorstuff]

30 minutes ago, adamOVD said:

@alex_sor So you're telling us you like vacuum stills?

I have 80" of reflux with a 4" column, and staying above 190 is a balancing act. I have not tried SPP though. If it was me id try 3" first. At that size you could always sell it. If you build it yourself, even come out ahead.  

the magic is in the SPP. what you using?

[adamOVD]

copper mesh.

[needmorstuff]

12 hours ago, adamOVD said:

copper mesh.

copper mesh is still decent.

[Alex_Sor]

Quote

I have 80" of reflux with a 4" column, and staying above 190 is a balancing act. I have not tried SPP though. If it was me id try 3" first. At that size you could always sell it. If you build it yourself, even come out ahead. 

Quote

My question is - 4" or 3" column for a 100l still and roughly 2m of room about the boiler, and with that choice how much power.
I am leaning toward the 4" and 5kw.. but as always there are smarter people than myself in the room so would love feedback.

I do not always follow this forum, so if you have any questions for me, I ask you to write a "personal letter". (private message) or write me a reminder so that I can reply to everyone in the topic that interests you. Thanks.

As for your question, for a tank of 100 liters, a 4-inch column, this will be a lot. For a 500 liter vacuum distillation tank with a full cycle of 4-5 hours, I design (consider it sufficient) a 150mm column. (see the picture). In my picture there is a 500 (1000) liter tank with 14 kilowatt heaters (water jacket).

 

[Windy City]

Can you remove the plates or the bubble caps? I had a 4" with 3 side columns before. It unfortunatly had a common drain and as in your pic it had three dephlegs, (it was a pain to dial in) If you could take out the plates or at least all the bubble caps and then have pumps on column 2 and 3 just use the dephleg on column 3. Fill all 3 columns with 15 mm Siporax (these are not rashing rings) or large format SPP (Odin sells this) and you will not have a problem making azeo at speed. 

[Southernhighlander]

1 hour ago, Windy City said:

Can you remove the plates or the bubble caps? I had a 4" with 3 side columns before. It unfortunatly had a common drain and as in your pic it had three dephlegs, (it was a pain to dial in) If you could take out the plates or at least all the bubble caps and then have pumps on column 2 and 3 just use the dephleg on column 3. Fill all 3 columns with 15 mm Siporax (these are not rashing rings) or large format SPP (Odin sells this) and you will not have a problem making azeo at speed. 

Windy City, your method would certainly work as described.  We generally add a thermostatic valve to stills that have more than 2 columns.  The thermostatic valve maintains the coolant temp for the dephlegs which is typically around 120 degrees F when it enters dephleg 3 in a 3 column still.  When the coolant comes out of dephlegmator 3 and enters dephleg 2 it is over 120 F and it is even hotter still when it enters the dephlegmator on column 1.  The coolant is plumbed in to the final condenser, out of the final condenser to dephleg 3 and from dephleg 3 to dephleg 2 and from dephleg 2 to dephleg 1.  In this way the coolant increases in temp with every dephlgmator it passes through and this helps the system to self balance.  No packing is needed to make azeo and vodka runs can be completed in as little as 7 hrs.  The thermostatic valve is place at the coolant input of the final condenser and the probe for the valve is in a special thermowell at the output of the final condenser.

[needmorstuff]

both are options, i think the latest thought on my side is to leave the 300l alone.. it's built and paid for an adding more columns not cost effective. 

we are a small gin producer, I do have a 100l and vodka is a new line for me so initial demand will be low.

I plan to use the 100l for vodka and rum with 2 different columns. the 300l will be for gin.

rum will have 4 bubble plates

vodka will have 1 bubble plate and a packed section, probably 4" diameter 1.5m tall with SPP, i should have 2m above the boiler so enough space.. not sure yet if i'll run CM or VM, probably CM using a danfoss valve to control the PC and Dephleg.

 

[Alex_Sor]

11 hours ago, needmorstuff said:

vodka will have 1 bubble plate and a packed section, probably 4" diameter 1.5m tall with SPP, i should have 2m above the boiler so enough space.. not sure yet if i'll run CM or VM, probably CM using a danfoss valve to control the PC and Dephleg.

For your data:

- column diameter 4 inches,

- the height of the column is 1.2 meters (the part where rings or washcloths are filled up).

- reflux ratio 1.5

- input power = 2 kW.

The results of calculating the theoretical efficiency of the packed column:

1) Equivalent Height of Theoretical Dish (HTD): 0.091m,

2) The number of theoretical plates: 14.2 = (height / HTD) + 1TD for a cube

3) Approximate result of separation efficiency: 95.1%

For the correct calculation of theoretical plates (transfer units), the composition of the raw alcohol in the cube should not be lower than 40%. Theoretical calculations have a number of disadvantages and more accurate calculation parameters lead to high errors. The number of theoretical plates can be rounded to the nearest exact unit and the efficiency to minus 1%.

 

[needmorstuff]

3 hours ago, Alex_Sor said:

For your data:

- column diameter 4 inches,

- the height of the column is 1.2 meters (the part where rings or washcloths are filled up).

- reflux ratio 1.5

- input power = 2 kW.

The results of calculating the theoretical efficiency of the packed column:

1) Equivalent Height of Theoretical Dish (HTD): 0.091m,

2) The number of theoretical plates: 14.2 = (height / HTD) + 1TD for a cube

3) Approximate result of separation efficiency: 95.1%

For the correct calculation of theoretical plates (transfer units), the composition of the raw alcohol in the cube should not be lower than 40%. Theoretical calculations have a number of disadvantages and more accurate calculation parameters lead to high errors. The number of theoretical plates can be rounded to the nearest exact unit and the efficiency to minus 1%.

 

Hi Alex,

Thanks for the considerations. I will have 6kw of power and will be using SPP, the exact SPP I will use is yet to be determined.

 

 

[Alex_Sor]

2 hours ago, needmorstuff said:

Thanks for the considerations. I will have 6kw of power and will be using SPP, the exact SPP I will use is yet to be determined.

I am an Engineer, and I really do not like guessing where you can count on a calculator

For your data:

- column diameter 4 inches,

- the height of the column is 1.2 meters (the part where rings or washcloths are filled up).

- reflux ratio 1.5

- input power = 6 kW.

The results of calculating the theoretical efficiency of the packed column:

1) Equivalent Height of Theoretical Dish (HTD): 0.110m,

2) The number of theoretical plates: 11.9 = (height / HTD) + 1TD for a cube

3) Approximate result of separation efficiency: 94.9%
 

...parameters have become a little worse.

[needmorstuff]

24 minutes ago, Alex_Sor said:

I am an Engineer, and I really do not like guessing where you can count on a calculator

For your data:

- column diameter 4 inches,

- the height of the column is 1.2 meters (the part where rings or washcloths are filled up).

- reflux ratio 1.5

- input power = 6 kW.

The results of calculating the theoretical efficiency of the packed column:

1) Equivalent Height of Theoretical Dish (HTD): 0.110m,

2) The number of theoretical plates: 11.9 = (height / HTD) + 1TD for a cube

3) Approximate result of separation efficiency: 94.9%
 

...parameters have become a little worse.

sorry, I wasnt suggesting i use all 6kw.. just that I had that available, plus SPP will have a better HTD (HETP) than rings, and I think I will have 1.5m

What calculator are you using btw?

[Alex_Sor]

I spent a lot of time writing my "Excel spreadsheet" and collecting various books on thermodynamic calculations and calculations (design) equipment for the production of alcohol and simply the separation of binary and multiphase mixtures.

Fortunately or unfortunately these books are in Russian or Ukrainian.

In Ukraine, the industry for the production of alcohol on an industrial scale (millions of liters per month) is very developed, there are several Universities in which many scientists have worked on these topics.

But that was all during the USSR. Now these directions are abandoned ...

I am picking up the "old Knowledge" ...

[needmorstuff]

4 minutes ago, Alex_Sor said:

I spent a lot of time writing my "Excel spreadsheet" and collecting various books on thermodynamic calculations and calculations (design) equipment for the production of alcohol and simply the separation of binary and multiphase mixtures.

Fortunately or unfortunately these books are in Russian or Ukrainian.

In Ukraine, the industry for the production of alcohol on an industrial scale (millions of liters per month) is very developed, there are several Universities in which many scientists have worked on these topics.

But that was all during the USSR. Now these directions are abandoned ...

I am picking up the "old Knowledge" ...

glad to hear it!

[Windy City]

28 minutes ago, needmorstuff said:

sorry, I wasnt suggesting i use all 6kw.. just that I had that available, plus SPP will have a better HTD (HETP) than rings, and I think I will have 1.5m

What calculator are you using btw?

I don't think 6 Kw will be enough. For a 4" column you need to use large format SPP ie; 10mm x 15mm and it requires a lot of power to run it properly. I am using 15mm Siporax (not the same as rashing rings) and am using 34 amps (34amps x 240 volts = 8160 Kw. This is giving me 2 gallons per hour of 95.4 % abv from 40 % low wines 

Hope this helps

[Alex_Sor]

As for the technology, the use of scrubbers (stainless steel wool) inside the columns is the best solution.

They have a "surface area" of 800 m2/m3, which is 20 times better than "Raschig rings".

For your 6kW of power, it will be better to use an 8 '' (220mm) column:

- column diameter 8 inches,

- the height of the column is 1.2 meters (the part where rings or washcloths are filled up).

- reflux ratio 1.5

- input power = 6 kW.

The results of calculating the theoretical efficiency of the packed column:

1) Equivalent Height of Theoretical Dish (HTD): 0.084m,

2) The number of theoretical plates: 15.3 = (height / HTD) + 1TD for a cube

3) Approximate result of separation efficiency: 95.2%

 

... this is the practical limit for "simple hardware"...

[Silk City Distillers]

What’s your rationale around the reflux ratio of 1.5?

[needmorstuff]

I only have a 100l boiler under this.. so a 6 to 8 hour run is fine.. 8" column is crazy.

From a 40% charge of 100l, I get 38l of 95% product, so only need a gallon or so an hour.

I can get more or less power.. but I thought that 6kw with the ability to control that down would be plenty.

[Alex_Sor]

5 minutes ago, Windy City said:

I don't think 6 Kw will be enough. For a 4" column you need to use large format SPP ie; 10mm x 15mm and it requires a lot of power to run it properly. I am using 15mm Siporax (not the same as rashing rings) and am using 34 amps (34amps x 240 volts = 8160 Kw. This is giving me 2 gallons per hour of 95.4 % abv from 40 % low wines

For your 4" column, you can get 2.84 gallons per hour. With a reflux ratio of 1.8, it turns out that the column is "underloaded by steam".

The steam speed can be increased by 20-30%. Your steam velocity is below 0.6m/s, and the vapor velocity is considered normal if it is within 0.5-1.2m/s.

You have a lot to strive for

2.84 gph can be achieved at a reflux ratio of 1.8, using 7489.2W (25,571.4 BTU).

[Alex_Sor]

6 minutes ago, Silk City Distillers said:

What’s your rationale around the reflux ratio of 1.5?

Reflux ratio is calculated automatically for me. (but I can change it at will)

The question here is that you are working on obtaining commercial alcohol (for sale), which means that you need to look for a balance "time - productivity - power".

For purer alcohol, a higher reflux ratio is needed, usually 1.8 if you do not want to build a tall column with 60 plates

Usually all calculations tell us that 12-16 plates are enough for 95+% alcohol. Finer cleaning requires more effort.

The "game of numbers" allows you to optimize dimensions and "power-time". I am glad that I spent several months reading special literature and creating a detailed step-by-step calculation of the distillation column and different options for reflux condensers and the installation as a whole.

[Alex_Sor]

With regard to the reflux ratio of the column.

Let's calculate for 6 kilowatts

Power input 6000 watts. Distillate sampling 300 ml/min. at a distillate concentration of 96%.

The theoretical distillate flow rate in the column is = 496.5 ml/min. if the selection of alcohol has not yet begun, and if it has already begun, the reflux ratio is 1.7 ...

Suppose we have a current power of 1 kW, -10% losses, then the current consumption (evaporation) is 0.9/920*3600*1000 = 3522 grams/hour.

If the current selection of alcohol is 300 ml/hour, at 96%, then it turns out 0.3*769.3(density) = 230.79 grams/hour.

So we can assume that the current reflux ratio is 3522/230.79 = 15.26 ...

This is just an example

 

Recommended column parameters.

The recommended maximum parameters are correct only for columns equipped with the best and most popular wire packing (scrubbing pads, scrubbers, etc.)

(column diameter in mm - power)

25-27mm - 800 Watt

31-35mm - 1250 Watt

38-41mm - 1800 Watt

44-47mm - 2450 Watt

50-53mm - 3200 Watt

57-60mm - 4050 Watt

63-65mm - 5000 Watt

These parameters are oriented to a packing height of 1meter, with an average porosity of 70%, a critical surface tension of 0.075 N/m, but they are not ideal, since they strongly depend on the packing density of the packing in the drawer, carried out manually and chaotically.

With an increase in the height of the packing and a decrease in the density of the packing, a large input power is possible without flooding the column.