How to find air leakage of rotary evaporator

The rotary evaporator is a conventional equipment in the laboratory. Air leakage often occurs in use and will slow down the normal vacuum distillation speed and reduce the efficiency during the test. If a large air leak occurs, the location can be quickly found and solved quickly. However, under normal circumstances, many air leaks are difficult to find. Here is a simple and practical method.

Connect the lab rotary evaporator and the vacuum pump, connect the rotating bottle and the collection bottle, then close all valves, open the vacuum pump and make the rotary evaporator run. At this time, if the vacuum degree occurs and can be pumped to the position of 0.08-0.09, but not above 0.09, it means that there are subtle leaks in the entire system. In this case, connect the pipe to the water source on the air release valve, open the valve, and use negative pressure to suck water into the rotary evaporator, so that each glass space in the rotary evaporator is filled with water. (When the water fills the condenser and collection bottle, rotating bottle and rotating shaft dynamic sealing system, the water will produce a certain weight. In order to avoid damaging the instrument, personnel must cooperate to hold each component firmly with the hands.) Then, observe where bubbles appear in the entire vacuum system, which means that there is a problem of loose sealing in this place, and then find the problem for further sealing treatment.

The vacuum rotary evaporator has a small size, compact structure and high efficiency, works intuitively, and has no metal ion pollution. It is suitable for laboratories, production pilots and extraction of precious materials.