Modifying the cooling on a pure distilling reflux

[Gavhancox]

I have a pure distilling reflux with the 600ml extension, and a needle valve instead of the little restriction valve at the output.

The output is very slow, I have stuffed around with the boiler temperature, I have now 22000 litres of cooling, but as the run gets on in time ( couple of hours) the output at best is a fast drip. I don't mind that with the heads, but would like a steady stream when in the hearts.

My guess is the top of the column and the output copper pipe heats up over time reducing or restricting the evaporation rate

I was wondering whether a leibig condenser added to the needle valve will help the output flow as I feel the standard condenser doesn't seem to be doing the job

Am I on the right track or is there another factor I don't know about

[scythe]

Im unfamiliar with that still coul you post a photo of the internals?

At a guess, if the output was angled down a bit instead of being nearly horizintal it would flow out a bit easier instead of pooling.
You might have quite a bit falling back down the column to the boiler.

Also ditch that chromed brass ball valve, seems a bit silly to have 2 valves doing the same thing.

[hillzabilly]

Try rotateing the needle valve 180' and see if ya flow improves,and I donot think haveing the other valve there is needed or helping ,and :text-+1: a little downwood angle would help but you may need a 45'degree fitting in that situation.If ya running it on a 50lt keg a product cooler would be a good idear,your fairly maxed out with the small coil in those units.cheers hillzabilly :handgestures-thumbupleft:

[Gavhancox]

Ok, I'll change the angle and get rid of the other valve (I only used that one to put the still into full reflux at the start). Hills what to do you mean by a product cooler?

[hillzabilly]

Ta me a leiberg after the needle valve is a product cooler not a condencer in the true sense ,as ya would not want to rely on it to condence vapour, but to cool the rather hot output that most LM stills give.cheers hillzabilly :handgestures-thumbupleft:

[hillzabilly]

If ya have vapour exiting your valve then haveing an extra condencer will not stop vapour loss from the top of the still,and in full reflux it will not help the stills efficency.cheers hillzabilly ;-)

[Gavhancox]

The strange thing is once I was well and truly in hearts the flow improved to a steady small stream and it stayed that way until the end. It's got me stuffed why the change