实驗室用管状薄膜式蒸发器

研究植物化学成分,在实验室中常采用沙氏(Soxhlet)回流提取装置提取植物成分。这种装置对于采用低沸点的溶媒提取,颇为方便。汤腾汉等曾设计将沙氏回流提取装置置于减压系统中,可以应用较高沸点的溶媒在低温进行回流提取,克服了沙氏提取器不便应用于较高沸点溶媒的缺点。但是提取液仍需较长时间貯存于受热器中,这是沙氏回流提取装置本身的特点。在研究植物化学成分的工作中,为了避免有些化学成分可因长时间受热分解破坏,常采用溶剂在室温渗漉,这种方法所得的浸液体积较大,需要在减压

A LABORATORY TABULAR FILM-TYPE EVAPORATOR

A laboratory tabular film-type evaporator is designed as shown in figure 1 (See Chinese Text). The steam is passed through the jacket D from E. The liquid extract to be concentrated is passed through the inner surface of tube B, consisting of a tabular thin layer (1 mm) liquid with the inner tube C where the liquid is heated, and evaporates into film in the inner surface of tube A under vacuum system. Its vapor is condensed in K, the concentrated liquid drip into tube C along the inner surface and is received in J. The time of heating for the liquid (70% alcoholic percolate) is 0.27 second, at temperature 45°±2°, 4.5—5 mm Hg, for one liter liquid per 4 1/2 minutes. The speed of evaporation is about 1000 ml of solvent removed from an alcoholic percolate in one hour, at 45°±2°, 4.5—5 mm Hg, and 2272 ml of solvent, at 55°±2°, 4.5—5 mm Hg.