Molecular distillation on the basis of the scraper evaporator internally mounted a condenser. After the feed mixture is heated with a light matter molecular motion to a certain distance condenser is condense into liquid jacketed glass reactor separation, heavy material and down along the wall. Because light physical vapor phase in internal condensation, namely vacuum pressure drop is very small coke to keep equipment in a high vacuum degree, not only can effectively remove liquid low molecular substances, such as organic solvents, smell, etc, and selectively steamed out the objective product, remove other impurities, so is seen as a protector of natural qualities, and regression. In the process of molecular distillation, escape from the heating surface molecules fly directly to the condensing surface, did not return to the heating the possibility in theory, so there was no molecular distillation is not easy to separate material. But in actual operation there are still shortcomings, so some places needs to be improved.
In order to ensure the high vacuum nutsche filter dryer system, separation materials should be degassed, large-scale industrial production should be a separate set of vacuum degassing system. Material liquid storage tank should be set heating and stirring device, so before the material liquid is sent into distiller, can first preheating in storage tank, in order to improve the efficiency of distillation. In the process of molecular distillation, feed speed is a very important operation parameter, so feed should be installed on the pipeline flow measurement and control instrument.
Fractions are solid at room temperature may state, thus fraction collection system should be set insulation or heating device, to avoid the distillate or residual liquid in the process of outflow may be cooling to solid and pipeline. On is mainly used for experimental study of small molecular distiller, receiver structure appropriate USES multiple receiving form, this can be achieved by adjusting valves or rotary table in the case of without a stop collecting fractions under different operating conditions, so as to bring convenience to experimental research. Constant temperature water bath temperature 50l rotovap control cooling system must have the heating and cooling two functions. If only the heating function, then the temperature under the condition of higher and lower distillation temperature, may be due to the temperature difference is too small and make the condensation effect is not obvious, resulting in a decline in output, serious when still can cause condensation temperature is not stable, increase the measurement error, lead to the result of the experiment is not parallel.
