Original title: Difference between thin film evaporator and molecular distillation apparatus Molecular distillation (MD) is a special liquid-liquid separation technology. In vacuum state, the mean free path of vapor molecules is greater than the distance between the evaporation surface and the condensation surface, so that the liquid mixture can be separated by using the difference of evaporation rate of each component in the feed liquid. Difference between thin film evaporator and molecular distillation apparatus: Conventional distillation technology is generally carried out at boiling temperature, but molecular distillation does not have such conditions, as long as there is enough temperature difference between the hot and cold sides. This is borne out by the fact that molecular distillation operates at temperatures well below the boiling point of the material. Moreover, if the conventional distillation is not careful, it is easy to appear bubbling, boiling and other undesirable phenomena, which of course will not occur in the molecular distillation process, because it is the free evaporation of the liquid film surface, the operating pressure is generally very low, thin film distillation ,rotovap distillation, and the heating time is relatively short. Generally speaking, evaporation and condensation in conventional distillation are reversible processes, and there is a dynamic phase equilibrium between the liquid and gas phases. Molecules escaping from the heated surface fly directly to the condensing surface, so there is no restriction on it. Although thin film evaporator and short-range molecular distillation instrument are both chemical production equipment and separation devices, there is a big difference between thin film evaporator and short-range molecular distillation instrument. On this point, we only need to compare the structure and performance of the two devices. First of all, the structural difference between the two is that the gas phase outlet of the thin film evaporator is at the top of the evaporator to meet the bottom-up flow law of the light component vapor, while the short-range molecular distillation instrument is just the opposite. Its gas phase outlet is at the bottom of the evaporator, mainly because the light components in the equipment are fully condensed on the built-in condenser. The second is the performance of the equipment, which is also caused by the difference in structure. For example, the low operating pressure of the thin film evaporator can reach 1mbar, while the short-range molecular distillation instrument is even lower, which can reach 0.001mbar. However, the molecular distillation instrument also has certain limitations. Due to the built-in condenser,thin film distillation, there is no way to add a bottom bearing to the scraped film rotor, which will produce a large vibration during operation, thus affecting the effect of the scraped film. Return to Sohu to see more Responsible Editor:. toptiontech.com
Difference between thin film evaporator and molecular distillation apparatus _ condensation
