Molecular distillation is a distillation process operating under high vacuum, where the mean free path of the vapor molecules is greater than the distance between the evaporation surface and the condensing surface, so that the difference in evaporation rate of the components in the feed liquid can be utilized. Separate.
(1) Feeding system, high vacuum of the system, the material to be separated should be degassed first, and the large-scale industrial production should be separately set up with vacuum degassing system. The liquid storage tank should be provided with a heating and stirring device so that the liquid can be preheated in the storage tank before the feed liquid is sent to the distiller to increase the distillation efficiency.
(2) The distiller, the retort is internally in a high vacuum state, and in the mass transfer and heat transfer studies of molecular distillation, the temperature and pressure distribution data inside the distiller are required, and the current ordinary molecular distillation device can measure The temperature of the evaporation surface heating medium and the pressure at the vacuum pump interface. Therefore, for a small molecular distiller mainly used for experimental research, a temperature and pressure detecting probe can be set at an appropriate position in the distiller to obtain temperature and pressure distribution data between the evaporation surface and the condensing surface.
(3) The fraction collection system, the fraction may be in a solid state at normal temperature. Therefore, the fraction collection system should be provided with a heat preservation or heating device to prevent the distillate or the residual liquid from being cooled to a solid and clogging the pipeline during the outflow process. For small molecular distillers mainly used in experimental research, the structure of the receiver should adopt a multi-stage receiving form, so that the fractions under different operating conditions can be collected without stopping by adjusting the valve or the turntable, thereby giving experimental research bands. Convenient.
(4) Cooling system, the constant temperature water bath that controls the temperature of the cooling system should have both heating and cooling functions. If there is a heating function, if the temperature is high and the distillation temperature is low, the condensation may be poor due to the temperature difference being too small, resulting in a decrease in the yield. In severe cases, the condensation temperature may be unstable, causing an increase in measurement error. The experimental results are not parallel.