I ran my new (home made) still again last night and have an issue with it that I'd like to run past you guys with my plan of attack for fixing this problem.
First things first; it is a 1m tall, 70mm ID tower packed with stainless scrubbers to about 800mm with a 180mm long 3/8th copper cooling coil above that. The take off tube is a 580mm long 12mm tube with a 320mm long 25mm condensing sleeve around it. This all sits on top of a 50L keg with a 2200w stainless rod type element. The whole lot (bar the tower cooling coil) is stainless. I had the cooling coil and the condensor sleeve running from two seperate taps to adjust seperately.
Problem:
With anything more than a moderate trickle of water flowing through the cooling coil it goes into total reflux. With no water running through it, it bleeds steam from the offtake pipe. Controlling the water flow was rediculously hard; the bathroom taps wouldn't provide enough control to find the happy medium needed to find the balance between total reflux and bleeding steam. Even if someone flushed the toilet it wreaked havoc with it.
My Planned Solutions:
1. More heating power. I think with more power the cooling coil would have to work harder and therefore be less temperamental with water flow. Alternative to this maybe insulating the keg and column (would that make enough difference?)
2. Manufacture a cooling water supply manifold to provide constant flow to the cooling coil and condensor via an adjustable valve on each line. This would be good because it would only require small adjustments throughout the distillation as opposed to constantly readjusting the flow.
3. At the moment I am only churning out neutral but in the near(ish) future when I want to pump out some rum or whisky I will have to run some form of voltage controller on the element to cut the steam back abit to avoid the bleeding issue.
In my head these solutions sound viable but I just wanted to bounce them off some more experienced people here to see if I am missing something. Many thanks in advanced for your help guys
Cheers, Heffers