Making a compound column for perfect separation of fractions

[Tropic]

I’m still considering my first build and will be for the next few weeks so please excuse my way out ides for a bit. It seems like stills are like pancakes - the first one is always not quite right, but I’d like to get close. So if you’re inclined, please let me know if this would work and if not, the physics of why not.

Anyway, what I’m considering is running a still with a condenser in the middle of two lots of packing. I’d run the coolant in the central condenser at 79 degrees C. This is pretty achievable with a high temperature pump circulating the coolant from the condenser and using a solenoid adding small amounts of cool water based on a temperature controlled thermostat. What I’m thinking is that this will run like two stills. The bottom half will reflux the heavier fractions and mostly pass up vapours that condense below 79 degrees. The top will then run like a normal still (I’ll be using a LM head) but the source vapours will be much more pure than coming straight from the boiler. In effect, I’m trying to force perfect separation of fractions.

The other thing I’m considering is making it in parts so I can remove and swap bits around if it doesn’t work or I want to run only the head as a pot still. The head, top packing, central condenser and lower packing will all be able to be separated. I plan to take each section pipe to a muffler man to have 120mm ends turned down so they can slide into the next section below (with Teflon tape to seal it). Is this viable?