Your dephlegmator acts as being a partial reflux condenser. It’s essentially a warmth exchanger that condenses a proportion of vapor and sends the alcohol-enriched liquid back for the plates to further enrich forthcoming vapor. The method explained stabilizes the ABV of the solution collected compared to primary pot stilling. Idea: https://felixiuckq.aboutyoublog.com/27367312/top-guidelines-of-reflus-stills