JaCh, to answer your last questions, continuous distillation was patented by Cellier Blumenthal in 1813 and I think that none of your ideas are new. I do not think that this is a good design and I do not recommend anyone to build it. I understand that this is a rather disappointing start of my message. I am sorry for that and what I can do is walk you through your design and direct you to the right direction.
Starting with your wash you use the heat from your product to preheat the wash. Actually you can do much better then that, you can use your wash to condensate all of your vapor as well. This is one of the advantages of continuous distillation, you do not need any cooling water. In the book
A Complete Treatise on the Art of Distillation published in 1830 a comparison is made between a discontinuous still and a continuous still on page 451. For the same quantity of wine distilled the discontinuous still consumed more then four times the amount of coal and it took twice the time. The continuous still did not use one drop of cooling water.
It seem to me that you are running your boiler dry. This is not a good idea as any solids will build up on the bottom of your boiler. In a continuous still your was will enter the top of the stripper, a column with at least 6 plates to strip the ethanol from the wash. The stripped wash, with the solids, leaves the boiler at the bottom.
The vapor form the stripper will enter the rectifier, a second column with 20 or more plates. The three plates in your design will not do the job. Not only do you need more plates, you also need a very good contact between the liquid and the vapor by forcing the vapor through the liquid. Baglioni tried in the same period as Blumenthal a double Archimedian screw in which the liquid flowed downwards and the vapor upwards with poor results as the vapor was forced over the liquid. (from
A Short History of the Art of Distillation by R.J. Forbes, no link here, you got to buy this book)
One of the peculiarities of the some of the alcohols you want to separate is that their volatility compared to ethanol depends on the strength of the ethanol water mixture. Isoamyl alcohol, propanol and butanol are less volatile then ethanol at higher ABV's, so these alcohols are trapped in the rectifier column and must be removed with a side stream in the lower part of the column. I find it interesting to read that Barney Five write in his topic
Simple, yet effective 2" plate column: Interesting notes: I took samples off the old Bok output at 5-10 minutes intervals, now a drain, and all were well below 20% ABV, and all were very oily and tasted like late tails. So oily my hands felt greasy..
I think that this is a good indication that fusel oils concentrate in the lower part of the column.
Besides the rectifier you need a third column to separate the more volatile components then ethanol.
Please note while you can't make cuts you can separate all the different alcohols. Google for “Bunker Stills” for a small continuous still for more information.
Some old but good books about about distilling that are worthwhile reading:
Power Alcohol published in 1922 and
Distillation principles and processes also published in 1922.
I appreciate your passion. Keep studying!
The only difficult thing a see is a constant feed. Reciprocal pumps are expensive but I think a small pump with a volume counter and a simple control loop can do the job (I did that once with a proportional valve and a volume counter, worked like a charm).
