can't get 100% reflux

[Royalwulf]

I have a 50L keg stainless steel modular still. I bought parts over a period of time. I started thinking I wanted 2" diameter then changed to a 3" diameter, but I had already bought a 2" dephlegmator.
So my current setup is, a 3" bubble plate with 4 plates, and optionally a 3" packed column, a reducer then a 2" dephlegmator. The rest is 2".
My keg has two elements, 3.4kw and a 2.4kw. I heat up on both then turn off the 3.4kw and run on 2.4kw. I have a power controller.
Although I am on tank water i have good pressure.

I can't get 100% reflux runniing on the 2.4kw, with needle valve fully open. If I go down to around 70% power then i can achieve it. I also can't achieve 2.0 - 2.5 L per hour that some say to run the hearts at.

Would buying a 3" dephlegmator give me what I need or is it a water issue?
If it is a water issue, what sort of flow do I need?

[The Stig]

To go faster you will need to go 4”
What’s the ID of your cooling water lines ?

[Royalwulf]

hose is 8mm id 12 mm od
Are you saying i wont get full reflux with 3" and 2.4kw?

[The Stig]

Probably not .
I couldn’t hold full reflux with braided hose because of the 6mm ID of the hose , switched to 11mm and that fixed the problem.
But , with a 3”-2” still you’ll never achieve the speed of a 4” still being 2.5-3lt/h

[B-Man]

I struggled getting full reflux with my 4" bubbler... it only has a short RC.
I upped my pump to 65w and put 19mm hose all the way through now I can run 2 stills off the same pump no issues....