Abstract: An experimental study for fluid hydrodynamic characteristics in thin water films falling down the outside of a vertical tube was performed with the analysis of several factors about the uniformity and stability of the film. Experimental data suggested that there is an optimum value of the annular distance in the range 0.5—2.0 mm and of the spray density in the range 250—700 kg/(m•h) for the falling-film device. Single-tube rotated 270°along the tube wall was used in the falling-film device in order to make the liquid flow tangentially. Several suggestions for the device design of outside tube falling film were proposed.

摘要： 在实验的基础上探讨了液体在垂直管外降膜的流动特性，分析了影响液体管外成膜均匀性和润湿性的影响因素，提出了布膜装置的环隙在0.5～2.0 mm有一最佳值，喷淋密度在250～700 kg/(m·h)之间有一最佳值，布膜装置的进液采用单管沿壁面旋转270°切向流的进液方式，并对液体管外降膜装置的设计提出了建议。