The rotary evaporator is extracted and concentrated under a negative pressure, and a vacuum device is required.The vacuum equipment we generally recommend to our customers is a circulating water vacuum pump.The circulating water vacuum pump is simple and convenient to use, and it is very suitable for the vacuum distillation with a rotary evaporator, and there are few faults.Not long ago, a customer who bought a 10 liter rotary evaporator said that，In use, the vacuum tube connected to the circulating water vacuum pump flows back.
When the rotary evaporator is in use, the vacuumed pipe is reversed, which has a great relationship with the degree of vacuum.Vacuum is the most important process parameter for rotary evaporators.The degree of vacuum is often related to the solvent used. Generally, the biochemical pharmaceutical industry is used as an example. They use water, ethanol, acetone, ether, etc. as a solvent. The occurrence of backflow water has little to do with the solvent used.At this time, it is necessary to detect whether there is air leakage in the rotary evaporator, especially the seal ring on each sealing joint and the rotating shaft, and to observe the vacuum gauge on the rotary evaporator, whether it can maintain the pressure for five minutes.The above is a solution to the reverse flow of the vacuum tube when the rotary evaporator is in use.