Sizing Lebig Condenser?

[Pamulli]

Are there any good guidelines for sizing a lebig type condenser? I've seen some that are 1 1/4" with 1/2" and other that are 3/4" with 1/2". In general is it better to have a larger volume of cooling water or does it not matter if your water flow is good? Also how much does the size of the condenser affect how fast you can run it and are there any good guidelines on how long the condenser should be?

Thanks,

[rad14701]

Less space between liebig walls provides more efficient thermal transfer... There is a calculator on the parent site that you might find useful...

Most here run 1/2" inside 3/4" with lengths ranging from 24" to 48" although there are a few that use shorter and a few longer... The majority probably fall in the 24" to 36" range...

Perhaps some of the members running propane fired kegs will chime in with their sizing specifications...

[olddog]

I am running with propane, I have a leibig 1/2" inside 3/4" and 36" long, it knocks down everything I can throw at it.

[Pamulli]

Thanks for the info. I'll go with 1/2" inside 3/4" and 36" long.

[astrangebrew]

3/4 over 1/2 is a great fit. 3/4, 1/2, 1/2 Tees are easy to got and modify
Treat the calculator as a minimum.
Go as large as you have room for and you distillate will come out cool.

SB

[myerfire]

I have a 1/2" inside a 1" and it is 33" long. The distillate comes out cool with a minimal amout of water flowing through it.
myerfire

[Coyote]

I run mine 1" over 1/2" 48" long
The 1/2" is wrapped with 10 gauge cooper wire
about 1/2" seperation between wraps
1/2" water feed from a 128 GPH pond pump
lifting from the bottom of a 55 gallon drum

Can't seem to overload it

[HookLine]

I use 1/2" inside 3/4", with the cooling jacket section about 20" long. Works very well.

[xx7777xx]

I went with 1/2" inside and 1" outside because I had the 1" hardware easily available that made construction real easy:

x7

[astrangebrew]

Sorry,

I forgot, the other really important thing is to mix up the vapour flow. Some folks use structured packing in the pipe (like in a column) others a bent up 12 Ga wire (see "turbulator"). I used 12mm twisted (3-4 twists per foot) copper ribbon. It kicks the vapour to the cooled skin and increases the efficiency.

SB

[kingearwig]

mine is 3/4 inside 1.5 outside and like 20 inches. does the job for me but it cost way too much.

[Hack]

I went with 1/2" inside and 1" outside because I had the 1" hardware easily available that made construction real easy:

LeibigCondenserPicture.jpg

x7

What's the valve for? That can be a bad idea. Closing off the end of the condenser on a pot still turns it into a bomb.

[xx7777xx]

What's the valve for? That can be a bad idea. Closing off the end of the condenser on a pot still turns it into a bomb.

My still is a a VM/Pot still combo so I of course need a valve to operate in VM reflux mode. As for safety my VM head is open to the atmosphere on the top as the reflux condenser knocks down any upcoming vapors. My pot still head has a hole with a cork plug to ensure there is a pressure release in case the valve would ever get left in the closed position.


x7

[Pamulli]

Sorry,

I forgot, the other really important thing is to mix up the vapour flow. Some folks use structured packing in the pipe (like in a column) others a bent up 12 Ga wire (see "turbulator"). I used 12mm twisted (3-4 twists per foot) copper ribbon. It kicks the vapour to the cooled skin and increases the efficiency.

SB

Seems like if you were going to go this route it may be better to have 3/4" inside 1" to get ample packing in or is that overkill?

[kingearwig]

mine has a piece of stainless scrubber material in the 3/4 pipe.

[Hawke]

I have both a 1/2 in 3/4 and a 3/4 in 1 with the jackets being 32 inches long. (Length was set to fit my stilling rack)
I use a twisted ribbon at the head and just a bit of copper scrubber at the output.
The addition of the twisted ribbon 'turbulator' reduced my water consumption by about 30%.

[xx7777xx]

I use a twisted ribbon at the head and just a bit of copper scrubber at the output.
The addition of the twisted ribbon 'turbulator' reduced my water consumption by about 30%.

How did you go about adding the ribbon into your condesnsor? Is it permenant, or removeable for cleaning?

I'm getting ready to do a stripping run with my pot still head and am thinking about adding a turbulator. I haven't really felt the need running in VM mode because it uses so little water.

x7

[Hawke]

All my liebegs have a union for attatchment.
The ribbon was made by cutting a strip same width as pipe ID and a little over 4 inches long.
Used the vise and a cresent wrench to give it a 180* twist.
Slides in with a snug fit.

[myles]

If you are still in the planning phase it is well worth having a look at the triple wall leibig designs. There are a couple of posts out there about them.

You can either have 1 vapour path between two cold surfaces or two vapour paths around a cold wall. If you go any further you are into xflow / shotgun condenser teritory.

The triple wall liebigs are well worth considering. The build is a little bit more complicated, but if you can build a normal liebig, then you can build a triple walled one.

You do get a massive increase in surface area to vapour contact with a very small increase in physical size. With liebigs as final product condensers, the vapour and condensate are both flowing in the same direction (not what you have in reflux condensers!!) so you can get away with small gaps between the surfaces.

[astrangebrew]

Hawk,

That's the first time I saw in writing your tubulator ribbon is 4". Mine is about 30" - NO - I'm not overcompensating...
I just assumed that is was best to go the full length. Actually I have a union above and below to allow adjustment and disassembly.
OK, maybe that helps to explain why it is always running ice cold (the liebig is overlong @ 27" - but I had the room and materials).
The heat source is 1500W but dialed back to 750 (a VM unit)
Maybe I should try some temperature experiments in the new year to see exactly what this ribbon adds to the liebig efficiency.
I have a slick digital thermometer on order http://www.dealextreme.com/details.dx/sku.7286 that will help. I also have a mess of condenser designs and calculations I need to pretty up and post. Maybe I should do a nice package in the new year.

SB

[Hawke]

Most of the phase change is going to happen in the first 1/2 of the condenser, unless you are pushing it to hard. Mine are used on a potstill at about a 20* angle.
For a vertical unit, the full length ribbon doesn't hurt anything. I think with a more horizontal one, much more than a 180* twist, might trap product.

[booger68]

Ok Hawke so the turbinator goes in the vapor path where the leibig connects to the column?Here a few weeks ago when you sugested it i thought that it went into the water jacket.My dumb ass took mine apart and put a small diameter copperline crushed it then wrapped it around the 1/2 in then put the 3/4 back on. I will have to try putting some up top where my union is and see how that works.
The tip about putting some copper mesh inthe bottom of the lyne arm did help some though.

booger

[Barney Fife]

Mine's 1" inside 1-1/2", about 5' long. I found it while scrounging; it was used as a domestic water heater heat exchanger, off a boiler system. Sweet! Way overkill, but hey, it was free...

I used to run it at an angle, something like 20-30 degrees, but with the recent changes to the still(the Barney Plate deal), I now have it completely vertical, and wow, what a difference in efficiency. I never really measured my water flow before, but it has to be near half now, with no other change other than having it vertical instead of angled. Seems counter-intuitive, but it sure works. I'm going to shorten this liebig soon, so I can have room for a parrot, and also just to take some weight off the column, and I'm pretty sure I can cut it in half and still have plenty of capacity. Oh, no twisty deals in it, but I do have some copper mesh loosely fitted inside, to give the vapor more surface area to condense on; not certain it's necessary, but it doesn't hurt. Right now, I use about 20 gallons cooling water for a 5 gallon strip run(roughly 2 hours' running time). I have a recirculating system and had to move the tank(old water heater), so I re-filled it during a run. Damn thing still wasn't full when I was done with the run....

[rad14701]

Ok Hawke so the turbinator goes in the vapor path where the leibig connects to the column?Here a few weeks ago when you sugested it i thought that it went into the water jacket.

Actually, both methods increase liebig efficiency... Turbulence in the water jacket results in a lower water flow rate requirement... Turbulence or structured packing in the vapor path improves thermal transfer which increases condensation capability...

[tykenfitz]

I went with a 5' long, 1/2" inside 3/4" because I had all the stuff free. It's WAY over kill for my small stock pot still, but I figure I can use it if I move up to a bigger boiler.