3"continuous stripper build

[pipes+hose]

So I've decided to try a continuous stripper. I figured I'd make a build thread and also see if anyone points out any glaring flaws or better ways to do things.

My design goal is to strip a 200L barrel of sugar wash in 1 day (about 10 or 12 hours max), so 20L per hour or better. I also want to do it without getting too much expensive, difficult to manufacture stuff, or significant modifications to my existing still/column. So far I've only ordered the stainless fitting to see if i can get it welded to the keg, i should be able to try that next week.

I currently have a 58L keg boiler with 2 x 1350 W elements and 1 wrap of bubble sheet insulation around it and on top. 59 x 3 inch column with 50 inches packed SPP and 3 wraps of bubble sheet all the way up. Homemade 2 to 3 inch reducer that is about 2.75 inches tall to attach the column to the keg using tri clamps. Boka head, 3/8 inch "double helix" condenser (17 turns, 10 inches long, made from 16+ feet of tube). Recirculated water with a radiator with fans. I have less than 0.5 inch clearance to the ceiling. As an aside i plan up upgrade the rad and add an extra burner to bring me close to 4100 watts in the near future (i hope I'll get around to that, my spirit runs could really use it).

The waste water (ww) will exit the keg from a hole in the side, a couple inches above the top of the elements, go through a U bend/trap, and go through a heat exchanger to preheat the incoming wash. Theoretically the ww should have a little more energy than the incoming wash needs to preheat, but i know the transfer won't be close to perfect so i am going to build it, measure how much more preheat energy i need then do something about getting more wash preheating from the top of the column. The ww preheater will be the second stage (due to the higher available temperature) and the top of the column preheater will be the first stage. The ww preheater will be a very long single wound coil (1/4 inch tube) in a 1.5 inch pipe as a shell. I think I'll run the ww through the shell and the wash through the inside coiled tube. I'll likely put a 3/4 inch sealed pipe down the middle to stop the water in the shell from just going down the middle and not engaging with the coil.

The first stage preheater may be a small coil in the boka section sitting just under the boka plates, because i don't have any height between the main product condenser (pc) and the top of the boka. Maybe 12 inches of 1/4 inch coil that intrudes down into the column, then back up to exit through the boka section. All of the heat transfer here will be stuck as reflux, so i don't want too much, but i do want some in the hopes i can run with my needle valve fully open and not have to regulate output speed vs additional reflux.

I originally planned to bring the preheated wash in through a hole in the boka section so i can avoid drilling a hole in my column and needing to plug it in spirit runs. Then run the wash injection down a tube in the middle of the column to the correct injection height. But now I'm thinking of bringing it in through the 2 to 3 inch coupler between the column and the keg. Not sure yet. I think with either config i will try injecting it with around 25 inches of packing below it. I can change the injection height by cutting the tube or connecting more.



Problems/things that could be better:

1) the boiler is too big, I'll have to put 20+L to get it started, that's more preheating and start time than ideal. But a new small keg with burners and cords would cost around 200 dollars.

2) this all assumes i can weld a stainless coupler to the wall of my key without melting a hole in it. This is yet to be seen but I've ordered a few parts to try.

3) the wash injection going down from the top of the column might lead to the wash getting cooled down by the vapors at that level being only around 78c. I guess it would be better to run up from the bottom. Maybe i could put the injection hole in my 2 to 3 inch adapter and run a pipe up. The 92 degree (best case) wash injection pipe might cause some condensation of the rising water vapour... but I'll have to hope it's not significant. On the plus side this would also help bring the injected wash up to temp before it's free to mix. I'll have to think about all that.

4) i don't have a power controller, so i have to hope 2700w or 4000w works, or i have to make a controller.

I'll get some more pictures once i have anything to show for it.