Air in cooling lines

[Sonofodin]

Hi there, so I'm having issues with air in my cooling lines. I have a 5 plate set up 50l keg and use a 2500l/h 40w pump for recirculating from a 200 litre barrel. Before my still starts producing I prime all the lines so open up both needle valves on the 2 inch dephleg and the 2 inch shotgun, nice steady water flow with no air locks or bubbles leaving the lines, I then shut off the needle to the dephleg as for strips I obviously don't need the reflux option. as soon as I turn up the temp, more so for stripping runs, I encounter a problem where it seems the temp at the top of the shotgun begins to create bubbles and then a large air lock from the hot out (located at the top of the shotgun). This obviously then results in intermittent broken water flow (very much reduced) then periods of a few seconds with no water out at all resulting in the shotgun doing next to nothing. I have a y shape configuration providing cooling to both dephleg and shotgun with use of needle valves. I also see that air begins to collect in the dephleg hot out too. As soon as I knock the heat or input down the air begins to purge. This is fine for the slow type spirit runs but for stripping I like to drive it a little faster. I've tried mounting my lines above and below point of entry and exit but to no real avail. Am I looking at needing a higher powered pump or is there something I'm doing wrong? Oh I run 2 x 2000w elements. If I can miraculously purge most of the air by god knows what techniques then running full 4000w purely for stripping seems to be no major issues for the shotgun but damn it's frustrating trying to maintain an air free system! I am still pretty new at all this so pls be gentle! As always thanks in advance!

[subbrew]

the air is coming out of solution as the water heats up. Using the same cooling water a second time should see less of a problem as the air is already out of solution. Are you hard piped or soft? I have soft hose to/from the shotgun and when bubbles start to form I can just lift the hose up above the exit and perhaps wiggle it to get the bubble started moving and then it usually is pushed the rest of the way out. I have to do this several times with fresh water.

The air will form a surface tension to the walls of the pipe/hose so sometimes a bit of tapping can break the tension and get the bubble moving.

[Sonofodin]

That's what I thought bud, guessed it was in essence boiling the water creating a bubble, my pump is placed at the bottom of the barrel where its cold and there is a distinct layer (obviously) between the hot water being kicked out at the top and the cold water at the bottom, maybe a little stir of the water in the barrel with increase the overall temp going into the condensers but not so much that it still cools. I do use soft lines and have def seen tension form on the walls, have tried smacking, whacking and wiggling and lifting often to no avail but will continue to experiment!!

[kimbodious]

If I get bubbles in the water leaving my shotgun condenser I pressurise the condenser by slightly pinching off the exit hose. You could swap the needle valve to the output side of the shotgun condenser. The bubbles you are seeing are more likely from turbulence after the needle valve than from boiling water.

4000W stripping runs and only using a 200 litre reservoir of cooling water? Wow!

[Saltbush Bill]

I'd agree with that......try the needle valve on the output side......this is one reason many recommend running that way.

[subbrew]

I was not suggesting the water was boiling. It is just heating up. Water will hold less gas in solution as it gets warmer. Think of the difference when you open a warm coke vs a cold coke. The warm fizzes much more because the liquid can not hold the CO2 in solution. So as the water heats, air dissolved in the water comes out of solution.

What size is your hose? (sounds like a rather personal question doesn't it). Perhaps go to a larger output hose. Some say to go to the needle valve on the outlet but I don't like it as it pressurizes the condenser. Guess I don't trust all my solder that much. Last resort is to put a valved vent at the top of the condenser where you can vent out the air.

[NZChris]

If you want to maximize the useful length of any condenser, the cooling water should exit from the highest point in the jacket, not from the usual right angled hose tail you see pictured all over the net.

[Sonofodin]

1F0E5CB4-2CB1-411B-8211-5B0F6707DC8E.jpeg (44.02 KiB) Viewed 680 times

Here is a photo of my set up. I'm thinking separate line for hot out for both pc and rc. Any advice welcome.

[Yummyrum]

Any advice welcome.

Well it’s not the advise you probably wanted to here …. and certainly not related to the topic , but, plastic looking hose on end of product condenser and those blue silicone gaskets in the column have got to be dealt with .

Check this out
https://homedistiller.org/forum/app.php/rules
Particularly Rule I

[Sonofodin]

Yummyrum, I couldn't agree more, I bought the still as is. As always any advice is much appreciated. I just thought being an all in one column it would be fit for purpose, I guess not. Would a ptfe wrap be of any use or do I need to replace all gaskets? Any links would be great for where to buy them.