Pot Still Leibig Condenser Question

[BaxtersDad]

OK, the question is, can you have TOO much cooling water flow on a Liebig condenser on a pot still? MH pot still, condenser is 13.5" long, half inch inner pipe inside a 1" jacket - not much resistance there. The pump is the $40 Harbor Freight 620 GPH / 11.5' head lift, which has no way to throttle it back unless I can get an inline valve to put on the supply side. I have not measured the flow rate but it is really fast. A problem or not? Thanks!

[Kegg_jam]

So you have a 13.5 inch Liebig?

Your gonna need all the water flow you can get.

Most Liebig's are more like 36 inch or longer. How much power are you needing to knock down?

[StillLearning1]

I agree with kegjam you might need a little longer Liebig. But to answer your question yes you can have too much water flow. Look into "shock cooling" I think its called. Basically you want a temp gradient along your liebig from the water in to out. So it should be warm where the vapor enters it and cool where the product exits it.

[BaxtersDad]

The Liebig is integral to the MH potstill. It is this guy. Unless of course you tell me this is not a Liebig, but as far as I know that is the basic Liebig condenser configuration.

[ranger_ric]

Buy first ....
Research Later.....

It's all good, AND purchasers are on the list !!! Yep they keep a list of everyone that BUYs a Still..

Welcome aboard.. Check out the link in my signature line. It has a lot of nifty info that changes your life IF you read it before you start distilling....

[midwest shinner]

I don't believe you can have too much cooling water on a pot still,as long as all the vapor is getting knocked down you're all good. The only downside is if you aren't using a cooling barrel of some sort and all that water is just going down the drain(being wasted) instead of recycling it, then I'd use as little as I possibly could so as to not be wasteful.

[BaxtersDad]

Buy first ....
Research Later.....

It's all good, AND purchasers are on the list !!! Yep they keep a list of everyone that BUYs a Still..

Welcome aboard.. Check out the link in my signature line. It has a lot of nifty info that changes your life IF you read it before you start distilling....

PM sent!

[ranger_ric]

That is a pretty small Liebig.. But as some folks have said size isnt everything... I use my pool as a cooling reservoir. perhaps you can move enough water through it to produce some quality distillation. Let us know how it works out.
LieBigs are awesome!! sometimes the Law doesnt even know what they are..

[Truckinbutch]

As has been stated :cool water in warm wate out . Shock cooling can be a real problem . A pot still needs to be driven , not pointed and shot .

[GrassHopper]

I have read all I could find on HD about "shock cooling" and I think it is a misunderstood term. I have come to the conclusion after much research on every thread on it, that it can mean different things to different distillers. Many have complained about huffing from their liebigs under certain circumstances. I had this same issue with my 36" liebig and with a 15.5 boiler and 2" column pot still. Solved it simply by wrapping a #10 copper spiral around an arrow and stuffed it up into the output about 24" and problem solved...no more huffing at any heat input. Once into tails I run full blast with a double ring burner and it knocks down every thing.
As far as shock cooling....I look at it the same way some do. I / we, could be wrong, but I see it this way.....the vapor that is in the product condensor cannot be changed into something different than what it is. Whether it is warm, hot or cold as long as it is being knocked down. The only factor that could change it is huffing, which may, and I say may with reservation, potentially draw other unwanted vapor into the path. Open to other thoughts on this. By the way I have a smaller 18" liebig on a 5 gal pot and it works fine too, but will not handle the higher heat all that well.

[GrassHopper]

Oh, I got sidetracked and forgot to mention my final point: No, I don't think you can have too much flow once your liebig has the spiral in it.

[ranger_ric]

OK Now Listne up guys... I just now reeread the thread titel...
I am sertain that your "consenser" is never too small as long as you beleeve that...

Carry On
RR

[BaxtersDad]

Damn typos! Well, we shall see what happens with the small "consenser" (condenser) and a flow like Niagra Falls from the pump...

OK Now Listne up guys... I just now reeread the thread titel...
I am sertain that your "consenser" is never too small as long as you beleeve that...

Carry On
RR

[still_stirrin]

There have been comments here before regarding the undersized condenser on that still head. The limitation is the contact surface area of the Liebig to the vapor path considering the vapor flow velocity. And simply forcing more cooling water through the condenser doesn't solve the problem.

Heat transfer is a function of mass flow (gpm) and temperature differential. If you pass the water so fast that it doesn't heat up during the flow, it actually becomes much less effective at carrying the heat away. So, to answer your original question....YES, you can have too much water flow.

Now, as I said, there have been many questions regarding that still head. A simple "repair" would be to add another Liebig on the outlet of the existing Liebig. Make a 14"-16" copper Liebig and connect (in series) the vapor tubes together with a compression coupling. Daisy chain the water jackets together...with the outlet from your extension Liebig to the inlet of the Mile-Hi condenser. Remember...cold in at the bottom and warm out at the top.

With the addition, you'll be able to run your potstill wide open for stripping runs without worry that you'll push vapors through.
ss

[BaxtersDad]

The still performed just fine as far as I can tell, undersized condenser and all, although I have nothing to compare it against.

I soaked the milk can and still head in PBW for 30 minutes and rinsed well. I had previously decanted some VERY old homemade wine, a 1989 cab and a 1995 blackberry. The corks were all intact and the bottles were full, and although the wine was certainly around the bend, it was not vinegary or moldy. I had one gallon of each that I ran separately.

The setup was fired by a 30K BTU propane ring burner, and cooled by a big reservoir with the HF pump. I had to add two gallon jugs of ice midway through the second run to get the cooling water cool again. I discarded the first 100 ml from each run. I ran the cab first, and probably ran it too fast. I let it go from drops to a steady slight trickle. I was just trying to get a handle on how things reacted to adjustments to the burner. I got 24 oz. of product at a temperature corrected 60%. After the still had cooled down, I emptied the milkcan, rinsed it out, put in the blackberry wine and the product from the cab run. This I ran very slowly, never exceeded 2 drops per second. I got a fair feel for adjusting the burner to control the output rate. I ended up with 16 ounces at 80% and 16 ounces at 70%. I thought this might be sacrificial alcohol, but based on tasting it, I see no reason to discard it. It is technically brandy I suppose but it is pretty much odorless and tasteless. Guess I have to study up on finishing and aging now.

I continually smelled and tasted a drop on my tongue as I went along, I guess I don't know what tails or fusel oils smell or taste like, it all seemed fairly constant. I just shut 'er down because the thermometer was at 200 degrees F.

So, I guess I now will have to ferment something!