Continuous STRIPPING still... again

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spencer321
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Continuous STRIPPING still... again

Post by spencer321 »

Alright my design is almost identical to others I have seen and tried to copy/simplify. 2x60 packed column, 2" 180 degree U bend, 2" to 3/4 reduction, from there 2 inline liebigs, both 1" over 3/4" both 24" long. Obviously the lengths and diameters of anything can be changed to make a better final product. The wash will enter the bottom of the top liebig, exit to a needle valve and dump into the packed collumn. A separate product condenser with water will be used encase the wash has to be slowed down to preheat more.

from my readings I understand this, the overflow on the boiler (not shown) should be very close to 212 degrees, the bottom of the column should also be very close to 212 degrees as well because no alcohol vapor should make it that close to the boiler. The U bend should be 173 degrees, the boiling point of ethanol.

Theoretical operation, I use a propane burner, seeing how this is for stripping I would probably have it cranked pretty high. Opening the wash valve too much should cause the spent wash and the bottom of the column to drop below 210 degrees, not enough wash flow and the U bend should read over 173, fine tuning the wash input should allow equilibrium assuming constant flow and constant heat.

I know this is very simple and generic but if anyone could give me any other ideas or pointers or criticism i would greatly appreciate it.
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manu de hanoi
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Re: Continuous STRIPPING still... again

Post by manu de hanoi »

the u bend will have the temp of boiling wash ideally, which is hotter than pure ethanol, the bottom must be maintained at the boiling point of water. Cant comment on Fahrenheit temps, get real and go centigrade. :)

If this is a welded assembly (and if not too), put the valve before the pre heating condenser, because if you put it were it is on the diagram that will require you to align perfectly the threaded tubes and on top of that you wont be able to screw it (or unscrew it) on both threads at once. Besides the proximity of the pipes would make it easy for the operator to get burned while adjusting the valve.

The output seems too close to the boiler top to be convenient.

If you need extra heat for pre heating , use a spent wash heat exchanger between the liebig pre heat and the wash feed to the main column (because the spent wash is hotter than the distillate you want to use it last). And if you do so keep in mind you often get Co2 released when preheating and that may mess up siphons if you make some.
spencer321
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Re: Continuous STRIPPING still... again

Post by spencer321 »

Bringing this back to life... I know I've been absent for 5 years but I was finishing school. The design hasn't changed much except I plan to route the boiler runoff through a condenser to utilize the thermal energy. The mash will be routed from holding tank, to first product condenser (1st pre heater), to boiler runoff condenser (2nd pre heater) and then injected above the packing.

The biggest fear is having good alcohol running out of your spent wash...

that being said, my major question is this... as long and my bottom thermometer directly above my boiling water reads 212... I shouldn't be be losing any mash correct?
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Re: Continuous STRIPPING still... again

Post by LWTCS »

Yes basically.
If you have solids your reboiler temps may be higher. That's a good thing.

The goal being to keep any alcohol that makes it to the reboiler will be flashed quickly.
Hopefully you'll be able to recover enough heat to get your beer feed hot enough?
Are you also planning on recovering heat from your re-boiler discharge?

EDIT: Ah I see your diagram. I think your going to struggle a bit
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Re: Continuous STRIPPING still... again

Post by spencer321 »

Diagram is 5 years old lol but yes I'm going to run the discharge through the usual cooling ports on a 2 inch shotgun and after my mash passes through the first product condenser it will then pass through the usual vapor path of the shotgun condenser heated by the discharge before being injected into the still
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Re: Continuous STRIPPING still... again

Post by spencer321 »

I usually ferment in a 55 gallon drum and it takes 3 stripping runs before I can do a product run. The goal is to be able to strip 40 gallons in 7-8 hours. That's 315 ml/min. Not exactly high output. I've done alot in 5 years, I hold 4 STEM degrees and make enough that my dream of going "pro" might be q reality, like to build something with some scalability in mind.
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Re: Continuous STRIPPING still... again

Post by spencer321 »

Plan on running 5500w variable power in a tiny 3"x30" tube for about .9 gallon boiler. Idea was to fill with water, turn on power until bottom thermo registers 212 then very slowly add mash until top thermo reads 180-190 then turn up mash volume to desired 315 ml/min, if bottom thermo doesnt budge I would increase flow rate until it drops below 212 then dial back 5% to maintain 212 at bottom thermo
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Re: Continuous STRIPPING still... again

Post by Swedish Pride »

Have a look at this design by swestill. Capable of 50l per hour.
stillplan.jpg
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manu de hanoi
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Re: Continuous STRIPPING still... again

Post by manu de hanoi »

@swedish , it's more energy efficient to have the mash go through the condenser first (<100C) then to the spent wash heat exchanger (100c)
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Re: Continuous STRIPPING still... again

Post by manu de hanoi »

spencer321 wrote:my dream of going "pro" might be q reality, like to build something with some scalability in mind.
the trouble in being a "pro" is more about sales, taxes, paperwork, inspections, fees than distilling.
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Re: Continuous STRIPPING still... again

Post by StillerBoy »

manu de hanoi wrote:the trouble in being a "pro" is more about sales, taxes, paperwork, inspections, fees than distilling.
+1 No truer words stated for any business startup.. then comes product distribution, and returning customers..

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spencer321
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Re: Continuous STRIPPING still... again

Post by spencer321 »

manu de hanoi wrote:@swedish , it's more energy efficient to have the mash go through the condenser first (<100C) then to the spent wash heat exchanger (100c)
This was my plan as the cooler mash going through the product condenser first makes more sense.
Swedish Pride wrote:Have a look at this design by swestill. Capable of 50l per hour.
stillplan.jpg
50l of mash per hour? It doesnt include any sizes or power, is that a 3inch column or 4 bbn or 6, what kind of power?
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Re: Continuous STRIPPING still... again

Post by LWTCS »

Watts per liter per hour manu?
About 6000 watts or no?
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Re: Continuous STRIPPING still... again

Post by Yummyrum »

LWTCS wrote:Watts per liter per hour manu?
About 6000 watts or no?
That seems pretty high Larry
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Re: Continuous STRIPPING still... again

Post by Swedish Pride »

spencer321 wrote:
manu de hanoi wrote:@swedish , it's more energy efficient to have the mash go through the condenser first (<100C) then to the spent wash heat exchanger (100c)
This was my plan as the cooler mash going through the product condenser first makes more sense.
Swedish Pride wrote:Have a look at this design by swestill. Capable of 50l per hour.
stillplan.jpg
50l of mash per hour? It doesnt include any sizes or power, is that a 3inch column or 4 bbn or 6, what kind of power?
4" column , 6kw element

Again not mine, just a plan i picked up on an other forum
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LWTCS
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Re: Continuous STRIPPING still... again

Post by LWTCS »

Yummyrum wrote:
LWTCS wrote:Watts per liter per hour manu?
About 6000 watts or no?
That seems pretty high Larry
Maybe?
When we were spitballing calcs on the other thread I ended up with about 408 watts per gallon, per hour. And was it HDNB that came up with just a bit more?
So 408 watts per gallon X 15 gallon per hour feed rate is 6120 watts.

Just hoping Manu could dial that approximation in closer for the group.

Edit: Ah Manu said 50 liters so 5389 watts per gallon for that feed rate
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Re: Continuous STRIPPING still... again

Post by manu de hanoi »

LWTCS wrote: Edit: Ah Manu said 50 liters so 5389 watts per gallon for that feed rate
I didnt put numbers in this thread, u prolly meant to address "swedish pride".

I forgot to mention that after pre heating the yeast dies and forms a nasty goo layer on the packing where it meets the rising vapour.
So it's imporant to let the wash rest and remove the bottom layer of yeast before distilling, but it's not enough, some kind of filter or sedimentation recipient (after pre heating) would help if you want to distill a lot. The big pros use inline centrifuges.
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Re: Continuous STRIPPING still... again

Post by LWTCS »

Green= Beer feed
Baby Blue= Low wines
Royal Blue= PHX
Purple= BHX
Brass= Bottoms Discharge
Red= PRV
Teal= AAV
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