New Liebeg condenser

[corene1]

Well I know i always say keep it simple but I was tinkering at work and thought of building a new liebeg condenser that would be a bit more efficient and use less water to cool with during a run. This is a practice piece I came up with. Basically a 1/2 inch tube with rings attached to create separate water cavities and a cross flow tube to move water from one chamber to the next to create a gradual temp increase to the top. The cross tubes would also act to create a bit of turbulence in the tube as well as additional cooling surface to condense the vapor. This is only a test section I made with some scrap to see if I could do it . I will go to a bit larger cross tube when I make the full unit to test. Probably use 1/4 inch tube instead of 3/16 bu it was all I had in the scrap box. I will make the rings about .001 tight and freeze the inner section and heat the outer tube to make a slip fit then when everything comes to temperature they will be a sealed fit.Has anyone tried this and what do you think?

[30xs]

Awesome looking work. How long are you planning to make it? I can’t really answer anything from experience, but thinking about it here would be my concerns....

1) A typical Liebig using a wire wrap can be overly efficient if coolant flow is too high. I would wonder how hard regulating the coolant flow would be?

2) Having all the corners inside where the cross tubes travel through how difficult would it be to keep droplets from hanging up somewhere along the line causing a little extra smearing?

3) I don’t know how to exactly calculate the area of the 1/2” tube that will be taken up by cutting 1/4” out of the center. Seems it would either have quite a bit of velocity, or cause a choke point making the vapor collapse and causing huffing? A 1/2” circle has and area of 0.196”, a cross section of 1/4” that is 1/2” long, I realize it isn’t rectangle but for simplicity, is 0.125”. That only leaves 0.071 square inches for the vapor to travel past. A puke on grains could plug that off fairly easily, I would think?

Remember, I am a rookie so I am only guessing at this.

Your work is always top notch. I would like the have about half of your abilities. Maybe someone with a little more understanding than me will chime in.

Edited to add the crude math, and puke risk.

[cob]

looks good, with your skills should be a piece of cake.
pm coming.

[still_stirrin]

The rings are similar to the baffles in a shotgun. And with the (well-aimed) crosstubes, the coolant is set up in a swirling motion around the jacket. Only thing is your prototype has a single vapor tube instead of a tube bank, like a shotgun has.

Again, the key design factors are 1) vapor velocity and the corresponding “dwell time” the vapor has in contact with the vapor tube walls, and 2) the surface area of the vapor tube(s) in contact with vapor and the coolant.

Looking at the mockup, I see that you will very likely have distinct zones where the temperature of the water will “step” up instead of a continuous gradient. This is because of the defined chambers between the rings hold more water than the crosstubes carry at any given moment. But the crosstubes will help carry heat back into the larger chambers, similar to the way a cold finger works.

An interesting concept, Corene. But it isn’t really more efficient, just different.
ss

[Twisted Brick]

I love the way you think outside the box, Corene. You always get my vote when it comes to advanced design because of your understanding of metal (copper) properties and your superior building skills.

If I interpret your photos correctly, you have taken a tab out of the shotgun book and added baffles to retard the coolant inside the shell, with the intent of reducing laminar flow while collecting more heat prior to moving through a 'transfer tube' into the next baffled segment. With this design, I feel the coolant throughput between baffled segments would have to be significant, since the hot vapor velocity would remain constant (albeit slowed slightly by the added turbulence), but the heated coolant would begin to lose efficiency as the temperature variance between vapor and coolant starts to diminish. The coolant would conduct additional heat as it transferred through the vapor tube, increasing the difficulty in conducting heat.

I'm not an engineer, but I feel a shell and tube condenser relies on a temperature gradient the same way a worm does in a flake stand. Your design may alter this gradient, resulting in a net loss of efficiency.

An example of your design, without the baffles, is shown below. Because of the constant coolant flow, this condenser proved very efficient, but too difficult for the masses to build. Here is the thread.
.

.
Posted at the same time as still_stirrin...

[corene1]

Not quite for sure how long it will be ,probably a 42 inch chamber with the rings at 4 inch intervals. The cross tubes should increase cooling surface contact area for the condenser as well as cause a turbulence in the vapor flow. My thought on the turbulence would be to increase vapor contact time. On a smooth straight tube I believe the center of the vapor moving down the tube doesn't cool until it is very far down the tube itself. The turbulence should break this smooth flow up pushing the center of the flow towards the sides of the tube itself. I say this because the bigger diameter liebeg I built was not efficient at all. It was a 1-1/4 over 3/4 with a spiral wrap . It took a lot of water to make it work well. I picture the vapor going down the tube with the contact area condensing and slowing down while the center keeps moving down the tube working it's way to the outside of the tube until it finally condenses. I may build the first one with the 3/16th tube to keep the tube area larger. Or I could use a larger tube and ovalize it to make it have less frontal area but more contact area. My runs have always been cleared mashes or washes , no solids in the pot to cause a solid blockage of any sort.I have puked a couple of rum washes but it has only been liquid plus there is a pressure relief on the pot itself just in case. My thought came from the old cross tubes in the vapor columns in a pot still. These would cause a small amount of reflux in the column with out a reflux condenser. My thought of making it more efficient is in terms of water flow used to dissipate heat while condensing the same amount of product. As far as the temperature gradient goes I can see how the little cross tubes may mot have the same temperatures as the chambers but the water is constantly moving up and around so in time I think it would actually develop a gradient. In truth the best condenser I have ever used was my old Graham condenser on my original 8 gallon pot still. I could do a full 6 gallon charge and only use a few gallons of cooling water for the run. I have all the parts to make a new Graham with a 1/2 inch id by 10 foot coil. That would be very efficient and cool just about anything i threw at it. Like I said a long time ago, I am no scientist just a tinkerer and my mind tends to wander from time to time. Mostly learn from trial and error. Plus I haven't built anything in a long time.

[NZChris]

Are you thinking of running vertical, or at an angle?

Most of my experiments only worked well at high flow rates because at low flow rates specific gravity took charge and I could feel the interface between hot and cold moving up and down the condensers almost the same as if there was nothing in the jacket.

With your design and method, there is little, to no, clearance for leakage between sections and I reckon it's worth a try.

[Royco]

Now I’m confused. Again. Just busy building first Liebig and elsewhere on the forum was told “make the Liebig longer”. SB Bill maybe?
Here 30xs says OP’s condenser may be “too efficient” with wire wrap? Just made drawings for a 48” Liebig in SS, this due to ease of availability of materials in our remote town. May use half inch copper for inner vapour tube and add wire wrap.
Is 48” way too long, considering the pot is 35L?

[corene1]

Now I’m confused. Again. Just busy building first Liebig and elsewhere on the forum was told “make the Liebig longer”. SB Bill maybe?
Here 30xs says OP’s condenser may be “too efficient” with wire wrap? Just made drawings for a 48” Liebig in SS, this due to ease of availability of materials in our remote town. May use half inch copper for inner vapour tube and add wire wrap.
Is 48” way too long, considering the pot is 35L?

I currently run a 42 inch long 1/2 inside of 1 inch liebeg on my 20 gallon boiler. The wraps are very tight inside the tube making a good swirl effect with very little bypass. The outer wraps on the 1/2 inch tube are at 1-1/2 inch centers for spacing. This works quite well , I was just trying to make a condenser that was even more cooling water efficient. If your liebeg is over sized it will just allow you to slow down the water flow going into the condenser and this will set up the proper temperature gradient in the condenser. You will always want to adjust your water flow depending on what you are running. On a strip run where you are running hard and fast it will take a higher flow to keep the gradient. Running a spirit run at a slower pace will require you to slow the coolant flow down to maintain your temp gradient. In essence you are adjusting the coolant to compensate for the higher or lower BTU's you are putting into the boiler.
A far as stainless over copper, you need to consider the different expansion rates of the 2 types of material and the stress it will cause at the joint where the 2 come together. I have done a couple of these and the longer the tubes the more difference there s in expansion lengths of the 2 pieces. My reflux condenser is 6 inches long and is copper tubes inside a stainless shell all silver brazed. No problems so far and it is 3 years old. I built a 42 inch stainless over copper liebeg and I had a joint failure where the copper comes through the stainless with only about 25 runs on it and it was silver brazed as well.

[Truckinbutch]

Now I’m confused. Again. Just busy building first Liebig and elsewhere on the forum was told “make the Liebig longer”. SB Bill maybe?
Here 30xs says OP’s condenser may be “too efficient” with wire wrap? Just made drawings for a 48” Liebig in SS, this due to ease of availability of materials in our remote town. May use half inch copper for inner vapour tube and add wire wrap.
Is 48” way too long, considering the pot is 35L?

I currently run a 42 inch long 1/2 inside of 1 inch liebeg on my 20 gallon boiler. The wraps are very tight inside the tube making a good swirl effect with very little bypass. The outer wraps on the 1/2 inch tube are at 1-1/2 inch centers for spacing. This works quite well , I was just trying to make a condenser that was even more cooling water efficient. If your liebeg is over sized it will just allow you to slow down the water flow going into the condenser and this will set up the proper temperature gradient in the condenser. You will always want to adjust your water flow depending on what you are running. On a strip run where you are running hard and fast it will take a higher flow to keep the gradient. Running a spirit run at a slower pace will require you to slow the coolant flow down to maintain your temp gradient. In essence you are adjusting the coolant to compensate for the higher or lower BTU's you are putting into the boiler.
A far as stainless over copper, you need to consider the different expansion rates of the 2 types of material and the stress it will cause at the joint where the 2 come together. I have done a couple of these and the longer the tubes the more difference there s in expansion lengths of the 2 pieces. My reflux condenser is 6 inches long and is copper tubes inside a stainless shell all silver brazed. No problems so far and it is 3 years old. I built a 42 inch stainless over copper liebeg and I had a joint failure where the copper comes through the stainless with only about 25 runs on it and it was silver brazed as well.

And there ya have it from a pro .
you have to know what you have and drive what you have . There is no 'fire and forget' in this hobby . It is all hands on .

[Royco]

READ MORE:

Thanks Corene1 this is comprehensive advice (and it sounds like you have done at least half a dozen runs before!).
Never gave expansion differentials a thought. Copper it is. Am fitting to a tea urn as 50L kegs are unavailable here (everyone starting brewing/distilling).
May fit a ss dog bowl as a dome and will connect a voltage controller.
What great info on this group. I would have made so many mistakes without it.

Just done this drawing ......
Don’t know why it is blurred but basically 50mm riser into 1” —> 1/2” Liebig, 1200mm long

[Royco]

Can a mod please tell me what I am doing wrong? Always get duplicate images

[Saltbush Bill]

Can a mod please tell me what I am doing wrong? Always get duplicate images

Fixed that for you, Royco.

Ive done that my self on this forum. when you select a file to down load it automatically puts it into the post, it also comes up beneath where you can say " add file or Image to post" if you click it as well you end up with the double photo. I havnt done a good job of explaining that hope your not to confused.
Most forums don't auto add the file to the post , you need to do that manually. I think that's why its happening.
Check the post to make sure there are not double attachments before you hit submit.

In my opinion a liebig cant be to efficient, you just adjust water flow or boiler heat input to get the result that you want. Longer = more efficient = less water flow needed.

[Royco]

Thanks Saltbush Bill for the explanation. And now I will sally forth and build my 1200mm Liebig, starting tomorrow!

[Royco]

Well, my rig is working beautifully, but i think the 48" Liebig is overkill. Have to control the garden hose tap to a mere trickle, not much more than the pencil trickle of the distillate. Going to fit a ball valve at the inflow nipple to get fine control.

So even at a trickle the outer tube is hot for about 1 inch unless I crank up the power. It could be half the length (2 feet) and still condense completely.
This is not an issue, besides moving the kit around.

[Saltbush Bill]

Better to have a Liebig with more cooling capacity than needed , than to have one with not enough.
In time you will appreciate the extra

[v-child]

Corene, I always like innovation and invention. Looks like this liebig may have some promise as adding more surface area and turbulence will always have a positive effect. I can always tell a machinist is at work, most of us couldn't get anywhere near the tolerances to "sweat fit" connections like you suggest. IMHO, I would go with the larger tubing for more cooling surface and less resistance. BTW, the acetylene regulator and control valve on the propane bottle is pure genius, thanks again.

[Truckinbutch]

Better to have a Liebig with more cooling capacity than needed , than to have one with not enough.
In time you will appreciate the extra

I couldn't agree more . Hard to put toothpaste back in the tube ,