伞板型布膜器对降膜蒸发性能的影响

引　言降膜蒸发器是一种高效、节能的蒸发设备 ,具有传热系数高、温差损失小、汽化表面大、物料停留时间短等特点 ,适于热敏性物料蒸发 ,易于实现多效操作 ,广泛应用于化工、轻工、食品加工、海水淡化等领域1].由降膜蒸发器的工作原理可知 ,降膜蒸发器能否高效运行主要取决于料液在换热管间的均布及其在换热管内壁成膜的均匀程度 .在降膜蒸发器换热管上端安装布膜器是一种有效的方法 .溢流型布膜器结构简单 ,但加工、安装精度要求高 ;目前常用的插件型布膜器成膜较好 ,但结构复杂 ,安装和检修都不方便 ,而且阻力相对来说比较大 .针对这一情…

UMBRELLA DISTRIBUTOR IN FALLING FILM EVAPORATOR

Falling film evaporator(FFE)is a kind of effective,energy-saving evaporating equipment,while the calculation of the heat transfer coefficient is not as accurate as is expected,which is partially due to neglecting the impact of distributor on heat transfer in FFE.For this purpose,a coefficient named Distributor Influence Coefficient is introduced which enable us to get the heat transfer coefficient form a new point of view.It is carried out with a new-type distributor--Umbrella Distributor,and furthermore,the influence of various factors is analyzed,which provides new thoughts for the calculation of heat transfer coefficient in the practical design.