Building a world class stripper ...

[Maritimer]

Maybe I should explain the operation of my continuous pot still. http://homedistiller.org/forum/viewtopi ... 16&t=33101

The idea is to have a small boiler, about 4 liters of liquid and 4 liters of vapour space, divided into 4 quadrants.

Wash is introduced into the first quadrant where it is boiled by a 1000 watt teakettle element. As more wash comes in, the liquid in the first quadrant overflows through a pipe into the second quadrant, where it is boiled again by a 1000 watt element.

This passing of the more-and-more ethanol-depleted liquid continues until it gets to the fourth quadrant where it overflow to the waste pipe.

The waste is about 0.5%ABV.

There is a pipe connecting each quadrant to the following one. The pipe passes through the quadrant wall, starting at the bottom of the sending quadrant and going through the wall into the receiving quadrant. There is enough quadrant wall above the pipe so that each section cannot boil over into its neighbours.

The vapour is about 30%ABV for a 10%ABV wash, which is exactly what you would get from batch stripping.

It is necessary to have some kind of separation and flow of the depleting liquid. If you just add more wash to the boiler, you would always be operating at about 0.5%ABV, assuming you want to have a waste overflow.

Maintaining the correct wash flow rate is not difficult, and once determined can be slightly adjusted for varying wash %ABV.

M

[Odin]

Thanks for sharing, Grey!

Maritimer, I am not very much into continuous distilling. Not saying because it is bad. Not at all. Just, my approach has always been to speed things up, so they can be done in a working day. Might be explained by my focus on pro distillers ...

Odin.

[Maritimer]

Odin,

Continuous pot stripping is faster than batch stripping. The boiling takes place at the same power level as in batch stripping, but there is no time and power wasted in heating up the batch. That can be a lot of time and power.

Let's say you have a 25-liter batch of 10%ABV wash (which is what I would use in my 30-liter boiler). At 4000 watts, that takes:

Power = watts = joules/sec = 4000 joules/sec.

The specific heat of 10%ABV = 8.0%ABW

Specific heat of water = 4.186 joule/(gram °C)

Specific heat of ethanol = 2.46 J/(g °C)

Specific heat of 8%ABW = 0.92x4.186 + 0.08x2.46 = 4.048 J/(g °C)

Boiling point of 10%ABV is 93°C, so the rise in temperature would be 93°C-ambient = 73°C.

Energy to raise the temperature of liquid = 25000 g x 4.048J/(g °C) = 101200 J/°C

Now multiply this by 73°C:

101200 J/°C x 73°C = 7,387,600 J.

Now how much energy is 7 million joules?

One joule is the energy required to move 1 newton 1 meter.

Newton is force, so in terms of weight, one newton would weigh 102 g = (1⁄9.81 kg).
So 7.387 million joules = 7.387 million n m = (7.387 million n m) x (0.102 kg/n) = 783,086 kg m

That is an incredible amount of energy to waste.

Now 4000 watts heating 25000 grams of 10%ABV would take:

power = watts = 4000 joules/sec

time = (7.387 million joules)/(4000 joules/sec) = 1846.75 sec = 30.8 min

So for every 25 liters, you save 30 minutes at 4000 watts = 2 kw hr.

55 gal = 208 liters. So (208 liters)/(25 liters) x 30 min = 250 min = 4.16 hours

That is assuming no loss to the environment.

So stripping 55 gallons would take about 5 hours less on a continuous still.

M

[DAD300]

"DAD, why do you feel continuous stripping and "on the grain" are not compatible?"

Most of the continuous strip designs rely on metered flow of the ferment/wash, and the remaining waste dropping out the bottom as water. Injecting solids into the column would foul the packing or trays.

I've spent a lot of time trying to separate the grain from the ferment to make the boiler charge compatible with internal electric heat elements or direct heat and I am convinced it is more effective to distill on the grain and deal with the solids left in the pot after distillation.

The problem there is that indirect fired boilers are expensive.

[Windy City]

Interesting thought! Maybe persue it and let us know how it works!

Another idea, closer to the umbrella, may be to put a cone under the umbrella to more gently brake up gasses rising up ..

Odin.

Excellent idea
The bottom of the cone could be piped right out the side into a exterior trap for your take off.
Then you would not need the 4" to protrude up into the 6".

Windy City

Ok again sorry for the drawing quality
But I think the idea itself is pretty good. The 4" expands to 6" at the funnel and condenser area. With the shape of the funnel and increase in diameter at the expansion the vapor should flow smoothly. The corugated stainless condenser is twisted up with a drip leg to center the condensate into the funnel. The outlet would need a vented trap to stop siphoning.
Tell me what you think guys.

Windy City

[Odin]

Looks good! I would advice you to dry test it. I mean prior to assembling it, run water thru the shotgun and see if it works as it should. No reflux should be able to bypass the funnel, otherwise it will directy diminish effectivity.

Odin.

[Odin]

I will limit my posting in this thread to a minimum. Mods have brought it to my attention that there are complaints about me selling my equipment all over the forum. And the name of my equipment has been used in this thread. No such thing is actually happening, of me trying to sell my products to you. Why? Well, easy, we don't target homedistillers.

Please know, that it has never been the intention of this or any other of my posts to promote my stuff. Only to share and give something back.

So ... please take this thread ahead and make me proud. Only thing I will still contribute on, in this thread, is in helping Windy build an awesome stripper. And I'll make sure not to mention my products any more.

Regards, Odin.

[DAD300]

So is there a continuous stripper design that handles solids of all grain?

[Windy City]

Hey Odin
I know this discussion started at my house, then continued on PM's and then landed here. For everybody else (for some background) I had picked up all the parts to make a 4" stripper pot still with 4" from the Boiler all the way to and including the shotgun, I was going to name her Bambi (don't judge she's just trying to put herself through nursing school ). When I showed Odin the parts and explained what I was going to do, you were able to tell his gears started turning and started thinking of better ways to do it, all the while sharing those ideas with us. After he got home he sent me a PM with more ideas and later another PM explaining he was going to share these ideas on the forums. Now after being at my home and meeting us and probably figuring out I could afford one of his rigs, what the man did was never once NOT ONCE suggest purchasing one of his stills. Instead he only helped me try and build something better and for that I say thank You Odin.


Now back to the design of a new stripper
The first drawing (yes I know the drawings sucked) I was using a dephlag But then on Odin's suggestion and everything Dad has posted and I have read about, I switched to the stainless corrugated (we get it in 500' rolls under the brands Wardflex or Gastite). My dumbass drawing program would not let me draw the condenser properly so I just typed it out where it will be. In the second drawing I also changed from the umbrella diverting condensate to a gap between the 4" and the 6" to a funnel with outlet tube. Now I just have to twist up the condenser real nice so that it is close but does not touch or transfer condensate to the copper walls and directs all condensate to the center and into the funnel.
What do you guys think? How do you think it will work compared to traditional designs? Personally I am pretty excited about trying it and would really appreciate everybody's input

Thanks
Windy City

[Hound Dog]

I will limit my posting in this thread to a minimum. Mods have brought it to my attention that there are complaints about me selling my equipment all over the forum. And the name of my equipment has been used in this thread. No such thing is actually happening, of me trying to sell my products to you. Why? Well, easy, we don't target homedistillers.

Please know, that it has never been the intention of this or any other of my posts to promote my stuff. Only to share and give something back.

So ... please take this thread ahead and make me proud. Only thing I will still contribute on, in this thread, is in helping Windy build an awesome stripper. And I'll make sure not to mention my products any more.

Regards, Odin.

Hmmm. Just like the other thread. I have enjoyed your sharing of knowledge and friendly banter. I have not felt the pressures of marketing.

Just voicing my opinion.

[Grey_Meadow]

I spent 30 minutes posting a reply earlier and it obviously went somewhere else ????
Odin, Nudging and suggesting will be missed. Don't go far. I do believe we are all big boys and girls here and can make our own buying decisions without Big Brothers guidance. I am well aware that you have a business in this business but I haven't seen any of you so called "advertising" enough said

Windy, I personally like my idea better, but then I am some what partial to my own opinions

No sweat on the drawings, this is chalk board talk and its the ideas not the pretty drawings.
From your sketch I am assuming the center funnel is about 4" diameter. Can the convoluted SS tube be wrapped in a spiral with a total diameter less than the diameter of the funnel? If so I think this would work well. Only suggest at the moment is that you include some kind of centering stays or supports on the condenser to make sure it stays centered. Once this is closed up you won't be able to see what is happening. You can sure include the "Drip Leg" but the convoluted tubing will have a lot of condensation coalescing spots and I would expect the condensate to fall from its entire periphery.

Grey

[Grey_Meadow]

Windy,

what does the trap on the outlet do for you ? I would assume that there is an open vent at the top of the column to make sure you don't build up pressure. And with that I don't see any vapor locks or blocks in the system.

Grey

[Windy City]

Windy,

what does the trap on the outlet do for you ? I would assume that there is an open vent at the top of the column to make sure you don't build up pressure. And with that I don't see any vapor locks or blocks in the system.

Grey

My thought on the trap was so vapor would not travel out the outlet tube and the outlet of the trap would have to have a vent so as not to siphon the trap. I would also think the trap would have to be primed before you start so the vapor doesn't escape before you had enough condensate to fill the trap. And yes the top of the column would be open vented for safety.
I need to start looking up some threads on the best way to twist up the stainless condenser to try and get it to center the condensate.
Another idea I had was to reduce back to 4" after the expansion/funnel section so the condenser would match diameter of the funnel
What do you think
Thanks
Windy City

[Lester]

Hello all. here is what I have been using to strip my washes (the continuous still project is temporarily on hold). So far I have stripped 240 liters on this set up. Posting this here cuz it seems consistent with what is being discussed.

condenser tube is 3" SS while the riser is 1.5". There's a roof at the end of the riser to prevent the condensate from making its way back to the boiler. The condensate outlet tube is 1/4" copper and it is enough. No vapor lock is needed.

Maximum Output rate is 6 liters per hour and I think it is being limited by the bottom area of the boiler and also the SS material of the boiler. If i want more output I need to increase the area in contact with the flames and also improve heat conduction by using copper material for the boiler.

You will notice that on my liebig, the water jacket is SS while the inner tube is copper. I am aware that the coefficients of thermal expansion are different but it is not a problem. I would like to point out that in a liebig, the inner and outer tubes are not subjected to identical temperatures and so the resulting expansion will not be the same even when using the same material for both inner and outer tubes.

I am using a double helix coil condenser wound from 12' of 3/8" copper tube, plus a 3/4" cold finger.

The cap just sits on top and is not soldered in place.

All joints were soldered using regular lead-free solder. No welds cuz I don't have a TIG welder.

[Grey_Meadow]

"Another idea I had was to reduce back to 4" after the expansion/funnel section so the condenser would match diameter of the funnel"

If you do this, you will need to extend the 4" section a fraction below the 4"-6" transition. If that transition is smooth any condensate on the walls would "stick" to the wall and slide past your funnel.

"I need to start looking up some threads on the best way to twist up the stainless condenser to try and get it to center the condensate."

Having never done this before.... I would run one line straight down and wind the return side around it back to the top. I'll see if I can't conger up a sketch if that does make sense.

I'll have to review some of the previous discussion, but is convoluted SS that much better than double coil copper? Copper has a MUCH better heat transfer (by about 25X). The gain would be in the extra area of the convolutions.

Grey

[Maritimer]

DAD,

If you are willing to accept continuous pot stilling, here is an adaptation of the original that should be able to handle a slurry instead of a liquid.

[/attachment]

The input is the lower pipe. The first quadrant gets filled until it start overflowing into the second quadrant through the space between the walls.

As more slurry is added, it moves through the quadrants until it comes to the fourth, where it exits through the higher pipe. The pipes are 1/2 inch ID, but they could be bigger.

Metering the slurry is another problem, but that's only a problem to be solved. As is pre-heating it.

I'm assuming that the boiling will agitate the slurry enough so that it flows like a liquid.

Here is another view.

M

[Odin]

Windy, I am not sure you need that trap. But maybe I am wrong. Here's my thinking:
- Your design is column based, so it should have an outlet to the air, at the very top;
- You strip, so throw up a lot of gasses, that are all (LM style) cooled down;
- This reflux, or actually stripped spirit, is collected in a "spoon" or funnel like contraption;
- That leads to a tube, where the spirit leaves the column.

Now, given an open route from column (horizontal) to that tube (horizontal) exists, you can even see your build as a sort of VM. In a VM gasses would split. Most (certainly in your case!) gasses will go vertical. But will gasses go "horizontal" and blow out of your collection tube? I don't think so, because at a true VM this only happens with abv above 84/85%. Now, since you have no packing, do not return reflux down the column, you will never get close to those kind of abv's. Ergo: not chance of vapours escaping through the outlet tube. And therefore, I think, no trap is needed.

Odin.

[DAD300]

Odin, so you think ethanol vapors, would not move toward the upper spent distillate tube? Hmmm

Maritimer...I like the divided boiler as a stripper.

And the AG boiler charge will agitate it's self at some point. In fact some boilers with agitators turn them off after reaching temp.

I however see spent grain solids building up in the first chamber and not making it to the second. That sounds bad at first and may be useful on a second glance. So, you have made me think about an old direct fire solution I have seen.

In very old designs the used a chainmail scavenger (agitator) to keep solids from burning on the bottom of direct fired pot stills.

What if the first chamber wasn't direct fired and it scavenged the solids, where they could be removed without disturbing the function of the other chambers?

Kind of like dumping and refilling the first chamber, while the others functioned.

Let me mull this for a while...

[Odin]

Hi Dad, not sure what you mean by the upper spend tube ... you mean on Maritimer's design? I was refering to Windy's approach ...

Regards, Odin.

[Maritimer]

DAD,

I've never done an AG mash, and I don't think I ever will, so I'm not really sure what it is. Can you describe the consistency? Is it quite dense, how big are the particles, etc?

Each of the quadrants only holds a liter, and with a 1000 watt element (could be 1500 watts, or a flame under the whole shebang, or a bain Marie), the agitation would be quite violent. If the particles stay suspended, they will probably flow though the system.

M

[DAD300]

Odin, Maritimer shows to side pipes below the column (one low in chamber one and one high on chamber four), sticking from the side of the boiler.

Maritimer, The solids are pieces of grain as large as a third of a grain of corn, wheat, rolled oats, cracked rice,...

[Maritimer]

DAD,

What about the consistency? Is this stuff like pea soup, or a broth with a few rice grains? Can you compare it to something common?

M

[Grey_Meadow]

What about the consistency?

Think cream corn or thin chunky oatmeal. I don't think there is anyway you will move the grains through your system, mainly do to the size. If you had a couple of gallons per chamber and 2" pipe in between you might be able to transfer the grain / wash slurry. At this scale I think you will stop the whole think up on the second liter.

JMHO, Grey

[DAD300]

Grey_Meadow has described it...loose oatmeal.

[Maritimer]

Think cream corn or thin chunky oatmeal. I don't think there is anyway you will move the grains through your system, mainly do to the size. If you had a couple of gallons per chamber and 2" pipe in between you might be able to transfer the grain / wash slurry. At this scale I think you will stop the whole think up on the second liter.

Well, how about 1" between the walls and only a small overlap, vertically?

I've changed the output pipe so that it overflows outside the pot. It is also 1" ID now.

With at least 4000 watts of power, the contents are going to be boiling so turbulently that it is hard to imagine that anything is going to get stuck. As more mash is put into the first quadrant, it will create a pressure to move the rest of the mash through the system.

The whole set of quadrants must be filled before the power is turned on, so imagine the whole pot boiling furiously.

M

[Grey_Meadow]

And now back to our regularly scheduled program...

Windy, attached are two sketches of the Condenser ideas you postulated. The corrugated tubing is 1/2 nominal (0.715 actual) The outer coil has an ID approx 1.5" (2 diameters) and the OD is approximately 3.0" and a total height of about 12". The total length is about 100 inches (8.4ft) (or 2540 mm for the others ! ) There should be enough surface area and turbulence to knock down the heat from a blast furnace.

The 6" version will need some form of standoff on the bottom of the coil. The 6" - 4" won't need the stand offs, but there does appear to be a restriction of flow as it passes the funnel and then quickly constricts and "I think" the 4" tube must extend below the transition to 6".

JMHO, Grey

Corrugated_.pdf

(69.14 KiB) Downloaded 137 times

[Odin]

Nice, very nice, Grey! But why not do the corrugated tube 6 inch wide? That way we don't have to close off part of the (6 inch) column and create extra pressure build up and so unwanted reflux. If Windy uses a 4 inch riser, I propose a 4 inch dephlag, like the picture on the right. The combination of 6 inch riser and a 4 inch dephlag I do not feel is necesairy. The width of the riser is not a big issue. Much, much less important than an unhindred vapour rise. Well in my experience.

Windy, I'd go for 4 inch riser and the 4 inch dephlag Grey describes (again: beautiful pics!). Four inches will suit you fine for your 10 kw power input. Easily!

Odin.

[DAD300]

Grey_Meadow...I like the 6" to 4" reduced top...I have put my 3" CC VM Head on a 4" column with no problems, but Odin is right, using larger CSST tubing is easier to build.

I have used the CSST all the way to 3/4" with hose clamped to the open ends for water supply.

[Odin]

DAD, if I remember correctly, you also "just" put a corrugated tube in the big outlet of your 3 inch VM as a product cooler and it worked fine, right?

This corrugated stuff if off the charts when it comes to cooling.

Odin.

[Grey_Meadow]

Odin / DAD,

I am just the instrument of sketching. I was putting on paper what Windy had proposed.

Having said that... If the cooling coil is wider than the funnel you will lose a large portion of the condensate around the outside of the funnel. Assuming the condensate is falling uniformly from the coil; A(6) = 28 in2; A(funnel) = pi D ^2 / 4 = 12.5in2; A(passing) = 28 - 12.5 = 15.5 in2. So with a 6" coil (dephlag) and a 4" funnel 55% will pass the funnel, ie REFLUX.

or am I missing something ?

This is a quick mod

Corrugated_b.pdf

(67.92 KiB) Downloaded 132 times