Liebig warm in the middle, and general Liebig questions.

[muscashine]

I've only run worms up until today. I did my first cleaning run with water in the boiler and the Liebig running coolant. The base of the condenser was pretty cool, down by the water inlet. The top near the water outlet was warm-ish but not too bad to touch. The center portion was pretty warm to the touch, warmer than the top.
Is this the normal way they feel when running? I was sort of expecting a gradual warming from bottom to top.
I was running the 4500 watt element full on at first and was getting a good stream out, but it was "surging" a bit. I cut back to about 13 amps and the surging almost went away, and the middle of the Liebig cooled off some.
Not sure how warm the distillate should be coming out, do I care as long as there's no vapor? Somewhere around 100 degrees?

[der wo]

That's not normal. How warm was the water coming from the liebig? As hot as in the middle or only warm as at the top of the liebig? Everything is copper?

[muscashine]

That's not normal. How warm was the water coming from the liebig? As hot as in the middle or only warm as at the top of the liebig? Everything is copper?

Everything is copper except the brass connections for my water Inlet and outlet. 1/2 inner pipe and 1" outter jacket. The water was pretty hot coming out at first but I increased the flow rate and cut the power back to the boiler. The water coming out the Liebig was probably as hot as the top, not as hot as the middle.
Not sure why there would be a hot spot in the center, unless that's where the vapor drops to liquid and gives up most of its heat...

[muscashine]

Oh and I'm running the Liebig close to horizontal, maybe 15 or 20 degrees below horizontal. Is it better to run it more towards the vertical?

[cranky]

Oh and I'm running the Liebig close to horizontal, maybe 15 or 20 degrees below horizontal. Is it better to run it more towards the vertical?

There has been a debate on that but my belief is a 45 degree angle is best. Do you have some scrubby or a copper spiral inside the 1/2"

[der wo]

Is it possible, that the liebig was not filled completely with water? Perhaps the hot area was unfilled? But normally the air would move up. Do you have turbulators between the pipes, which perhaps hinder the air to go up? Is the liebig almost horizontally?

[der wo]

Ok I'm too slow with posting, you wrote now, it's almost horizontally. My belief is, that 45 degree or more is identical, but you should not go well below 45.

[Danespirit]

Well, there is something wrong there..
It shouldn't behave that way...are you sure there are no airpockets inside your Liebig and nothing that causes a blockage?
I have mine set to 20 -30 degrees or so and it works just fine...no issues keeping a temperature gradient as expected (cold at the bottom, warm at the top).
Edit: The 1/2" pipe ain't by any chance touching the outershell i.e. it's describing a bow?

[muscashine]

It's possible the inner pipe is close to the outer shell on on side in the middle. I made very small crimps in the pipe every two inches at 90 degree angles for turbulence. The pipe had a sight bow in the middle. It was touching at first but I corrected it, I thought. That's probably it, less water flow in the center where it's hot.

[muscashine]

Oh and I'm running the Liebig close to horizontal, maybe 15 or 20 degrees below horizontal. Is it better to run it more towards the vertical?

There has been a debate on that but my belief is a 45 degree angle is best. Do you have some scrubby or a copper spiral inside the 1/2"

No there's no spiral inside the water or the vapor tube, and no scrubbie. That's why I added the crimps instead. i read a lot on here and it seemed there's a debate on whether the spirals in the water chamber do anything at all, so I didn't add that.

[shadylane]

I bet if you lower the end of the liebig so it's at a 30-45% angle the problem will go away.
Things will also be different when you run alcohol vapor through it.
One other thought, and I hate to say it. Crimping the inner tube on a liebig might not be a good idea.
It would make it more likely to get plugged up. The little bit possibly gained in efficiency is easier to get by going bigger.
My preference is to always use a water jacket that's only 1 size bigger than the inner tube.
An oversized water jacket weighs more and probably is less efficient.
Editing while show was posting

[skow69]

I used the crimped path design also. I think it is very effective.

Try running it vertically. It should be cold at the bottom, then abruptly turn hot where the phase change happens and stay hot to the top. At least that's how mine runs. I have never had a smooth gradient through it.

[muscashine]

I bet if you lower the end of the liebig so it's at a 30-45% angle the problem will go away.
Things will also be different when you run alcohol vapor through it.
One other thought, and I hate to say it. Crimping the inner tube on a liebig might not be a good idea.
It would make it more likely to get plugged up. The little bit possibly gained in efficiency is easier to get by going bigger.
My preference is to always use a water jacket that's only 1 size bigger than the inner tube.
An oversized water jacket weighs more and probably is less efficient.
Editing while show was posting

The crimps are very shallow, I based it on what I read here. I'm going to do a sacrificial run next week, I'll try it with the Liebig more vertical. I'm not sure it would be easy to fix without cutting the reduction ends off the Liebig. I can't hit both ends with propane at the same time, which is what it would take to snatch the inner core out. If it doesn't work I'll resort to a redo.

[shadylane]

If "The crimps are very shallow" I wouldn't worry about it.
I'll bet when you do the sacrificial run, the liebig will work fine.

[shadylane]

How long is your liebig?

[skow69]

If "The crimps are very shallow" I wouldn't worry about it.
I'll bet when you do the sacrificial run, the liebig will work fine.

+1. If it is not getting plugged, I don't see any advantage to making it round again.

[muscashine]

How long is your liebig?

53 inches of vapor tube from the elbow to the output. 47 inches of water jacket.

[Truckinbutch]

That should be more than enough cooling . More angle to eliminate an air bubble .

[der wo]

4500W through a 1/2" tube? I would not like such huge pressure and vapor speed.
There is a calculator for condenser size on the parent site. 4500W through 1/2" should have 108 inches to cool it down to room temp without problems. But that would not change the pressure. With 3/4" it should have 70 inches.
If you really want to use 4500W, you should build a liebig with an inner tube of 3/4" or more. Stuffing with scrubbies helps much, so probably you can use less length than the calc advises.

[muscashine]

That should be more than enough cooling . More angle to eliminate an air bubble .

Thanks, that's what I'm thinking, I might just replace that inner tube anyway...I know it's not completely straight, it does have a sight bow but I thought that wouldn't make a difference.

[muscashine]

4500W through a 1/2" tube? I would not like such huge pressure and vapor speed.
There is a calculator for condenser size on the parent site. 4500W through 1/2" should have 108 inches to cool it down to room temp without problems. But that would not change the pressure. With 3/4" it should have 70 inches.
If you really want to use 4500W, you should build a liebig with an inner tube of 3/4" or more. Stuffing with scrubbies helps much, so probably you can use less length than the calc advises.

It seemed to do fine knocking down all the steam on full boil. Once it got going I cut the power back to about 2/3 full, so really I'm running 3000 watts through it.

[der wo]

Ok, 3000W is different. But if you have to replace the inner tube anyway, it would be cheap and easy to replace it with 3/4".
-colder distillate
-smoother distilling
-less water
-less pressure. What means higher resistance against leaks. But if this could be an issue, depends on the details of your build.

Edit: But you could do a little sacrifical run first, to evaluate better your situation. Perhaps something of what I wrote is also right for you.

[Danespirit]

It's possible the inner pipe is close to the outer shell on on side in the middle. I made very small crimps in the pipe every two inches at 90 degree angles for turbulence. The pipe had a sight bow in the middle. It was touching at first but I corrected it, I thought. That's probably it, less water flow in the center where it's hot.

That's what i thought...
Copper is a excellent heatconductor so if it touches or is even to close to the outershell, this problem will occur.

Edit: I am affraid, unsoldering is the only solution to solve this problem.
Maybe you can get away with just unsoldering one side of it (the side that causes the trouble).

[muscashine]

It's possible the inner pipe is close to the outer shell on on side in the middle. I made very small crimps in the pipe every two inches at 90 degree angles for turbulence. The pipe had a sight bow in the middle. It was touching at first but I corrected it, I thought. That's probably it, less water flow in the center where it's hot.

That's what i thought...
Copper is a excellent heatconductor so if it touches or is even to close to the outershell, this problem will occur.

Edit: I am affraid, unsoldering is the only solution to solve this problem.
Maybe you can get away with just unsoldering one side of it (the side that causes the trouble).

I agree...
I don't think the inner tube is touching the wall, but I do think it's really close and maybe the water isn't flowing well on that side, its restricted, so the water is flowing faster along the bottom side.
I figured out if I can unsolder the reducer on one end and slide it off, then I can unsolder just the core tube from the reducer on the other end and push it through. That's a lot simpler than cutting anything. I'll have to boil some water through the whole thing again, and do my vinegar run, but I'll feel better fixing it now than waiting until my sacrificial run is done and having the same issue.
While I'm at it I'm going to shorten the arm coming off the side of my column. Originally it was there for the take-off point for the worm and it needed to stick out. Now I have this 4 foot liebig on the end of it and the whole thing looks a little off balance. Even if I run the Liebig at a 45* angle, there's plenty of room for it to be right by the column before it hits the still.

[cranky]

4500W through a 1/2" tube? I would not like such huge pressure and vapor speed.
There is a calculator for condenser size on the parent site. 4500W through 1/2" should have 108 inches to cool it down to room temp without problems. But that would not change the pressure. With 3/4" it should have 70 inches.
If you really want to use 4500W, you should build a liebig with an inner tube of 3/4" or more. Stuffing with scrubbies helps much, so probably you can use less length than the calc advises.

Damn! Really??? Myself and many other members run liebigs that are 3/4" over 1/2" and have no problems cooling with no more length than 36". mine is 36" long and can knock down everything my 5500W element can throw at it. On stripping runs I collect cold distillate at a quart every 4.5 minutes. I do have a spiral of wire inside but either your figures or that calculator are wrong about how long a liebig needs to be.

Edit:I don't mean to sound like an ass but those figures are simply not accurate in real life. I went and looked at the calculator and it is not accurate when it comes to liebigs.

[der wo]

As I mentioned in another thread, I copy & paste from http://homedistiller.org/forum/viewtopi ... 87&t=58447
"Yes I know, most use 1/2 + 3/4. And I wonder every day. I first had the inner tube OD 18mm and after that 22mm. It's such a huge difference better operation. But yes, most use it and they are happy, so perhaps I'm wrong, but I cannot explain it.

For me, the calculator worked always perfectly. With a scrubbie you can go shorter."

"I simply found out (I have build three potstill-liebigs in my career), if I use the calculator with the preset settings (water input 15°C, output 50°C, vap temp 82°C and 850W/m²C) and use a smaller liebig than calculated, huffing will start.
I started my journey with a small potstill and upgraded size and power step by step. And before building a new condenser, I tried the higher power with the old liebig first. That did not function very well, but I had success, to fix the problems with a turbulator.
The data (I always used hotplates):
- First I had 1500W. 70cm, 16mm ID inner tube, worked without problems.
-The same condenser with 2000W was huffing strongly, but no vapour escaped. I could fix it with a scrubbie.
-The new liebig: 81cm 20mm ID had no problems with 2000W without scrubbie. But now with 2600W I have a little huffing, but can fix it with the scrubbie."

My boiler is insulated. The very short riser is 54mm, the pipe to the side is 28mm, the angle of the liebig is about 55 degrees.

I don't mean, a liebig can not knock down more than the calculator says. But there will start problems like huffing with my still.

[cranky]

While I don't know why a simple spiral of wire or a bit of scrubbie would make it possible to run a third of the length called for I know myself and many others who run 36 inches have no problems knocking down everything they can throw at it, in my case 5500W. There is no way most of us would run 11 foot long condensers and though plenty are running shotguns more are running liebigs and doing just fine with 3/4 over 1/2 and 30-36" long. Some say the 3/4 over 1/2 works better than the 1" over 3/4" and weighs a lot less. I actually have a 24" extension that could be added to mine in case I ever needed it but I have never had to use it as an extension.

[shadylane]

JMHO
The liebig calculator in Parent site is very conservative. Condensers as much as 60 or 70% smaller work.
I'm going to agree with Der wo, 3/4 inside 1" is much better than 1/2 X 3/4

[shadylane]

Muscashine, what are you using to solder with? By chance is it a torch?
The reason I'm asking is, large copper fittings are expensive.
There's simple ways to avoid using them.

[skow69]

Looks like my liebig is undersized by 32%, if I did this right: I used default temps, 13 mm tube, and 1313 watts. [2 internal elements, A) 1500 w and B) 4500/240 on 120, so 1125 w for total 2625 watts. VM equal vapor path, RR 1:1, so 1313 watts can get to the liebig.

The calc says I need 31".

I've got 1" over 1/2" crimped path, hangs vertical, 21" wet length, no scrubbie. I turn the water down to a trickle most of the time. Cold well water run to waste.

Font colors are cool.

EDIT spelling