Internal recycle thermosyphon evaporator - in which the recycle tube has an annular sleeve taking the feed

摘要

Thermosyphon type recycle evaporator has a central recycle tube with vertical tube calandria between the tube plates. The recycle tube has an outer pipe forming an annular space into which a feed pipe discharges and which is blocked off from upper an separation space. There should be a single recycle tube with its coaxial jacket. The jacket is sealed at both ends into the tube plates. The recycle tube discharges into the jacket tube at a short distance above the latter's opening into the lower evaporator space. The arrangement combines the advantage of the external recycle by shielding the recycle tube from the heating medium and at the same time preheating the feed without any loss of thermal efficiency.