Too late for data analysis I'm of to bed. Gut feel is twin versus single column results in no significant difference in overall run time. There was however a LOT of differences in the operation of the VM still in dual column mode. Basically the gate valve is redundant, all you need is on/off control here.
In single column I ran the gate valve at ~20% open. In dual column mode I had to fully open the gate valve AND lift the reflux condenses 90mm or 50% out :scared-eek: .
I tried lifting the condensers and restricting coolant flow, nothing I tried would increase my volumetric output.
Run details on the morrow, time for sleep now.
PS I should add that the heating element used in my previous run was 2.4kW and the borrowed element was 2.2kW so another variable to throw in to the mix.
Cheers,
Mech.