Abstract: 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.