The continuous Stripper (pimp my still)

[Master-Peter]

As I got more and more convinced to do a stripping run first and then a spirit run I wondered if there might be some way to improve that process. Thinking that for the stripping run batches are usually bigger, than for a spirit run I squeezed my brain how to make it in a relatively small pot. Here is what came out.


The wash will go thrugh a coil in boiling water, the vapor should go up into the column/head, the hot backset will leave on the other side and could be again shugered up to be reused.

The idea is to allow stripping runs for every size of batch on a more or less continuous basis. The setup will allow no cuts and no takeoff of methanol. This must be done in the second run with a normal setup. My idea is to make a connector at the head, so I can use the head from my normal setup or even the column (all to be interchangeable). The cooling water outlet will be connected to the boiler to fill up evaporated water. The outcome from the stripping run could go directly into a boiler for the spirit run. Probably some thermometers should be added. Maybe a low volume pump could be fit from the first tank ...

At least that way the stripping run could be done in pure copper, to enhance taste. The setup does not need a big boiler to process a bigger wash occasionally.

This is just a raw idea, on a very theoretical basis, so far ... that I'd like to discuss with the more experienced fellows.

[absinthe]

the coil wont work as the bubbles from it boiling will push the wash out before it can lose all the alco.. your better off injecting the wash into the tower about 1/3 to 1/2 up from the bottom so as it runs down through the packing it has the hot vapour running past it to strip it

http://homedistiller.org/forum/viewtopi ... ing+flange

[Master-Peter]

By the way .... in at least 1 european country the legality of a distillation apparatus is determined by the size of the boiler. That has to be below 0.5ltr. As the size of the boiler in above setup is represented by the lower coil, it should be possible to make a legal apparatus with a nice output.
Than of corse the spirit run has to be made in a 0.5ltr setup too, but this seems at least more reasonable as the low wines are more concentrated.

Maybe I'm wrong wih this. Would not be first time.

[Master-Peter]

Thanks Absinthe. Did not see that threat yet. Than this should work. Tried to input all the information from that posting



This way I could just juse a household hotwater maker, have about 0.5ltr in the boiler and run ist continuous as the 0.5ltr will be exchanged quite fast.
The good thing is ... you could start and go to bed (even this is not advised) for:

1.) Wash supply ends => Water boils => Switch off
2.) Cooling water ends => Water boils => Shut off
3.) Electric bill exeeds limt => money ends

The boiler might be just a 20cm piece of 3" copper and the column maybe 1.5" copper ... With a lets say 1500W power input and a output of 0.5ltr per hour ... it should run happy for 30 hours.

What do you think?

[The Chemist]

Gosh...wouldn't she run out of clothes eventually???

[Master-Peter]

Gosh...wouldn't she run out of clothes eventually???

If that happens I'll know what all these Viagra Spam mails where for

[Master-Peter]

Hey folks,

is there nothing to complain? No ideas to be taken into consideration?
If the engine is that perfect I'll make it over the weekend and give it a try. Otherwise, please ... those who know it better ... give as much shame and shit on me as possible, so I can revise it again.

Will it work? Can it be improved? Is it that perfect? Any ideas?

All the idea is theoretical based, from what I found or whas put on in this forum. So in case it's perfect, it's perfect because of the forum, because of great people here answering dumb questions, from a newbie like me, again and again.

Thanks
Peter

[violentblue]

check out my stripping still design


and yes you could build the boiler to be less than 1/2 litre

[Hawke]

I see one liebig working to preheat the wash and another to cool it back down?
I think you want the wash to be as close to temps as you can get it, and keep it mostly liquid, before going into the column.

[Master-Peter]

Thanks Violentblue,

haven't read that thret yet. Seems to be somehow similar, but I think mine might be easier to make. But ... on the other hand less effective, for coils transfer heat better than a jacketed condensor.
But anyway really interesting to be on about the same way ....

Did you get your design working? How does it perform?

Cheers
Peter

[Master-Peter]

Hey Hawke,

great to see you are still with me.

Nope... the idea is that the wasted wash does the first step of preheating (probably to about 40-50C) the second step shall be done from the cooling water of the condensor to about 60-70C) .... so its meant to be a 2 step preheating design.

OK?

Cheers
Peter

[Master-Peter]

Dear Violentblue ....

after thinking about your design, you could enhance wash heat through using the temperature of your "water out" as far as I can see. On the other hand don't you risk to water down the product when you introduce steam, that does not come from boiling the wash?

This is just from my novice understandeing ...

Cheers Peter

[violentblue]

I've been putting some thought into how to recoupe the heat from the spent wash, But currently the wash is preheated by the hot distillate, which would be the first stage of cooling, second stage of cooling would be with water, the water would then feed the steam boiler.

your design would probably be easier to build, buy mine is an evolving excersize in efficiency. and no I haven't built it. its based on my experince with a stripping colum I made and ran once and gave away. it worked well but had some distinct drawbacks, which I've adressed and improved upon in this design.
as with any design, guarenteed there will be something I never though of, problems or design faults that will crop up, but its a work in progress, that I may build one day.

[violentblue]

On the other hand don't you risk to water down the product when you introduce steam, that does not come from boiling the wash?

by the time the wash reached the bottom of the column (theoretically) all the alcohol will be removed.
steam will condence out as the alcohol robs the heat away, since it has a lower boiling point.
the only thing you risk "watering down" is the flavors.

thats the idea behind the 3 way valve. you can choose to load the boiler with water or spent wash.
that way if you are stripping a run for vodka or neutral, you would use water, but a rum or whisky or other flavored product you'd use the spent wash.

for a flavored product I'd reccomend mixing 50/50 stripped distillate with unprocessed wash for your spirit run.

[Hack]

I see what I think might be two problems with the current continuous stripper design. I'm not sure you'd have all the alcohol out of the wash you'd want by the time it exited through the waste tube. Also I think your vapor may have a tendency to want to push out through the waste tube as well. This last could be solved by having the waste tube end below the surface of the liquid creating some resistance for the vapor. The vapor will then follow the path of the least resistance and go up the column, maybe. To solve the possible problem of not having all the alcohol you want from the wash maybe redesign this as a small pot with a reflux head with the twist of instead of letting the condensed water drip back into the pot it is caught and sent to the waste tube.

[carlos castenada]

Hi all,

The main problem i see with any design like the above, is that the heat input would have to be matched
to the folw rate of the wash entering to be heated. you don't want wash to exit with alcohol in it.
you may get it balanced correctly for one wash, but how much would you lose setting the rates up.
and since each wash won't be the same exactly, would it have to be set up again.

Thanks for the drawing, i really enjoy having to think aboout stuff like this it really sharpens your theory.

cheers

[glassman]

been wondering if you could set the column temp with input flow and heat input to around 95deg and be constantly pulling ~ 20% low wines. don't think it would take too long to dial in. gman

[violentblue]

my current design (not pictured) retains some wash in the bottom of the column, the plan is to have a tempurature monitor there which will be the input for a thermostatically controlled valve. said valve will control the input of the wash. as long as the wash reaching the bottom of the column is a certian tempurature you can be sure that all the alcohol has been driven off.
the higher the tempurature of the wash at the bottom the lower proof the distillate will be.

again, depending on how much flavor you want, if you want more flavor to come through- then run at a higher tempurature and spent wash in the boiler, less flavor- narrow the window down and run water in the boiler.

[Nykter]

I see four issues with your drawing:

- the order of the preheaters. The cooling water from the condensor will be somewere between 30 and maybe 40 C, and the spent wash exiting will be 100 C. Switch it, somehow, and you will gain in efficiency.

- You will need an air vent at the top of the spent wash heat exchanger, or it will empty the boiler by syphoning it...

- If its a stripper with no reflux you wont need the slanted plate head. It will be much easier to build by just using a Liebig condenser.

- You need a way to control he wash input, otherwise you might loose ethanol.

[seravitae]

Just a suggestion, if you are working with small stills for legality purposes, the easiest way to 'extend' it into a large still is simply with some glass tubing and 2 peristaltic pumps, and a small control system. One pump for draining and one pump for filling, and you just need a small program on your computer and a computer relay controller kit or whatever. It's not *continuous* but it would be small, quick, automated stripping runs. Since it would be automated, it's essentially continuous as long as you keep the input container filled up I'm not sure if that will help you but yeah.

[Master-Peter]

Still revising

thanks for all reply and advise. Lets talk about this:


http://img244.imageshack.us/my.php?imag ... visxw6.jpg

In this drawing you'll miss the cooling water, for I think cooling the distillate only with the wash in a "oversized" Liebig can work. But I'm not sure. If that works we could even save water cost.
I cut the plates and coils - because ... its just a "stripper"

Any "complains"?

Peter

(Shit ... soehow the image does not show up anymore...)

[seravitae]

if you're worried about water consumption use a fish tank pump with a small radiator for your condensor. I've been using the same 4 liters of water for my still since day one

[absinthe]

Still revising

thanks for all reply and advise. Lets talk about this:


http://img244.imageshack.us/my.php?imag ... visxw6.jpg" onclick="window.open(this.href);return false;" rel="nofollow

In this drawing you'll miss the cooling water, for I think cooling the distillate only with the wash in a "oversized" Liebig can work. But I'm not sure. If that works we could even save water cost.
I cut the plates and coils - because ... its just a "stripper"

Any "complains"?

Peter

(Shit ... soehow the image does not show up anymore...)

no good.. your loseing all the heat from the boiler.... you will get much more out of that than in the condencer...

the hotter to mash on the way in the faster you can run it

[Master-Peter]

no good.. your loseing all the heat from the boiler.... you will get much more out of that than in the condencer...

I do not understand
Could you please descibe this fool prove -for me ?!

the hotter to mash on the way in the faster you can run it

Yes exactly what I hope ...

[Nykter]

I'm still missing the air vent on the spent wash exit...
Otherwise OK

[Master-Peter]

I'm still missing the air vent on the spent wash exit...

Will be introduced in the next drawing ....

Anything else fine ?

I still try to figure out the satement of Absinthe ...

[absinthe]

all the boiling spent wash in the last posted pic is going "to ground" (waisted) all the energy in the boiling spent wash is wasted it should be recovered

[Master-Peter]

all the boiling spent wash in the last posted pic is going "to ground" (waisted) all the energy in the boiling spent wash is wasted it should be recovered

Now I got it Thanks.

Well the intention with the spent wash is to use it hot for adding shugar and recycling. I did not plan to convert the heat for this would mean to introduce a pump or something like this. My idea was - what is not there can not fail.

[snuffy]

think about it this way: your mash is (say) 8% abv. Where's the heat going? 92% water must be heated to just below 100C. That's all specific heat. Then the 8% ETOH has to heated above boiling - over 80C. That's specific heat up to boiling and then latent heat of vaporization to get to vapor.

Roughly 80% of the energy is going into the water and 20% is going into ETOH vapor. And no more than that can come back out.

For safety and control reasons, sacrifice the condenser waste water. Your heat recovery will come mostly from the water. A temp controlled valve sensing the boiler and controlling the mash inlet is one design possiblity. There's a lot of headroom on the boiler temp (if you are not driving steam up the column). There's very little ETOH in 95C water.

[Nykter]

think about it this way: your mash is (say) 8% abv. Where's the heat going? 92% water must be heated to just below 100C. That's all specific heat. Then the 8% ETOH has to heated above boiling - over 80C. That's specific heat up to boiling and then latent heat of vaporization to get to vapor.

Not really true, the part that has to be boiled is everything you condense as low wines. In a stripper, thats some 50% water and 50% ethanol. In a refluxing system, you will have to count the amount of heat removed from the system in the reflux condenser, some 5-10 times what you condense as product.

Roughly 80% of the energy is going into the water and 20% is going into ETOH vapor.

I won't argue with that, haven't done the math. It might as well be true.

For safety and control reasons, sacrifice the condenser waste water. Your heat recovery will come mostly from the water. A temp controlled valve sensing the boiler and controlling the mash inlet is one design possiblity. There's a lot of headroom on the boiler temp (if you are not driving steam up the column). There's very little ETOH in 95C water.

According to this diagram, it is 7% ethanol left in a mash with a boiling point of 95C.

It shouldnt be difficult to control the feed by temperature if you place the temp sensor some 100 mm up in the column, giving the headroom you need. This is the same strategy you should use in a batch reflux system with temperature controller, placing the sensor somewhere in the middle of the column length. And, you should indeed be driving steam up the (bottom of the) column, if its ethanol in the vapours leaving the boiler, it has to be alcohol in the liquid thats in the boiler as well. Liquid which will exit through the spent wash exit.