Sealing system for a rotary evaporator

摘要

A rotary evaporator has a flask (23) which is rotated about its axis by a drive apparatus (25). A vapour passage pipe (15) conducts the vapour from the rotating flask (23) through the drive apparatus (25) to the fixed condenser (3). A shaft seal (6) is arranged between the fixed and movable vapour-conducting parts. This shaft seal is held by an intermediate piece (5) which is arranged on the condenser-side end (24) of the vapour-conduction tube. For additional protection of the shaft seal from the medium, the end (24) of the vapour passage tube moves in an annular-shaped channel (10) in the intermediate piece (5). As a result, in reflux distillation, damming of the distillate flowing back is simultaneously avoided. The sealing system is simple in construction and the shaft seal is readily accessible from the condenser side. Teflon coating of metal parts of the drive apparatus (25) is not necessary. <IMAGE>