Problem with a VM using a 'gas line condenser'

[UKbiker]

I am in the process of building a VM/Boka combo still and goofed up my first condenser attempt. So in the meantime I figured I would get a gas line and coiled it to use as a condenser. It is a 2" column with 48" of copper scrubber packing. I have a 2"x2"x1" tee with the gas line above the tee. I haven't added the plates yet so the boka reference was just where I am heading.

I hooked it up to do a cleaning run with water and vinegar using a 15.5 gal keg which was about a third full. I heated it with propane on a fish fryer and felt it get hot and rise up the column until steam started coming out the top. At this point I turned on the cooling water and turned the heat down a little. With the water wide open it wouldn't knock all the steam down and there was a little coming out the top. The cooling water wasn't very warm so the gas line must not be very efficient since it wouldn't knock it all down.

The take off goes thru a 1" gate valve into a 90' to a liebig condenser and the valve was open and the gas line ended about 1.5" above the take off. I let it run for about 15 more min with a little steam escaping from the top though much less than with the water flow off. I never got anything coming out of the liebig. I shut it down and stuffed my last 3 copper scrubbers around the gas line to try and slow the steam and increase the cooling surface area but a little bit of steam still escaped and still nothing from the take off. Out of curiosity I took off the entire take off so it was just the tee going to atmosphere. And no steam came out the take off? I could turn the cooling water off and steam flew out the end and turned it on to a small amount and I could see quite a bit of water dripping off the gas line but no steam came out the tee.

Does this sound weird? If I knocked all the steam down would that change anything? I don't see how this could possibly work if I switched to alcohol? Does anyone have any suggestions on what to change or do different? Do I just need to let it run longer? I'm at a loss at the moment. Should I just finish the still like I planned and make a good coil condenser and add the boka plates and try again? I could see where it would have worked if I had the slant plates but would still like to have the VM option available and wondering how you get steam to divert out the tee?

Any thoughts or suggestions would be greatly appreciated!

[DAD300]

Condensers work a lot dif with etoh than water... water requires more power to vaporize and more power to condense than alcohol.

There are lots of posts here about, "EH, my still vents steam during the cleaning runs!" and then it works fine for alcohol.

First to tell if there was a real problem, we'd have to know more about the reflux coil and the amount of water you were running.

Second, the reflux coil could be keeping vapor from getting to the takeoff if it is too close. Also, reflux can cool the top of the packing and cause water to pool on top. You should only need a little mesh around the reflux coil.

I'm betting you're fine and the dif between water and alcohol will be the fix. You will use less power and less cooling water with etoh in the boiler. All the temps will be 20-30 degrees F (10-20c) lower.

[thatguy1313]

I also turn on my cooling water when I fire up. Helps get the line cool before vapor hits it. I recirculate the water though.
What size tubing (diameter and length) gas line are you using?

[shadylane]

Just a thought
If the reflux condenser is not very efficient, you can always turn down the heat.
Personally, I'd try doing a sacrificial run and see how it works.
You might want to look at the posts by dad300

[humbledore]

I have a similar setup. A 48" x 1/2" coiled gas line works fine, I do have a scrubby in the top. The main difference between this and my old dual coil copper is that because it has more water in it it is slightly slower to register changes in coolant temp. But it knocks down more power than my coil did.

[DAD300]

Very easy...Corrugated Stainless Steel Tube will not transfer as much heat as Copper. But the CSST has twice as much surface are as the smooth copper tube. The corrugation also puts it ahead in the turbulence department.

[Hound Dog]

CSST is hell and gone thinner than copper. I think this allows for a decent heat transfer. My coil knocks down everything my propane burner can throw at it. When I convert to two electric burners, we will see. I can always take 15 minutes and wind another one with more coils using more tube. I bought a roll knowing I would have use for it in the future.....

[UKbiker]

I guess I just don't understand why if there is a ton of steam coming up, none of it goes out the tee even when there is nothing connected to it to provide resistance and/or a longer distance to travel? I guess I can just dump vinegar in the take off tubing/valve/liebig and plug the ends and slosh it back and forth to clean it. I just can't imagine alcohol vapor magically directing out the tee when water vapor doesn't.

[Kegg_jam]

I guess I just don't understand why if there is a ton of steam coming up, none of it goes out the tee even when there is nothing connected to it to provide resistance and/or a longer distance to travel? I guess I can just dump vinegar in the take off tubing/valve/liebig and plug the ends and slosh it back and forth to clean it. I just can't imagine alcohol vapor magically directing out the tee when water vapor doesn't.

Funny, I thought the same thing when I was cleaning my ccvm. I even PM'd DAD and he reassured me that water vapor doesn't act the same as alcohol.

I had to cap the top of my column to get steam out of the Liebig.