Maintenance of vacuum pump of freeze dryer

Daily maintenance of the vacuum pump of the freeze dryer: 

Before turning on the vacuum pump, check the oil level of the vacuum pump, which is generally 1/2 of the oil sight glass.

1. Before turning on the vacuum pump and butterfly valve, if the whole box is evacuated, pay attention to closing the box door and valve; Pay attention to personnel safety.

2. Before the vacuum pump starts to vacuum the box, make sure that the back box is dry. If there is water vapor, the temperature of the condenser should be lower than -45℃.

3. If the equipped vacuum pump needs water cooling, it must be ensured that the cooling water is in place before the vacuum pump is turned on, and the temperature of the pump body can be touched by hand during operation.

4. Check whether the pump can draw the ultimate vacuum in a normal time; observe whether the vacuum pump produces a noise when it is running; whether the vacuum pump oil and the connection parts on the pump head are loose, etc.

5. Let the vacuum pump open the gas vibration valve every week and run it for about 2 hours under no-load conditions; check whether the pump body leaks oil and whether there is any noise during operation.

6. If the pump oil appears milky white, black, or other colors, it means that the oil has deteriorated and emulsified, and the vacuum pump oil needs to be replaced; if the upper part of the oil appears white turbidity composed of small white droplets during operation, it means that there is water vapor or organic solvent entering the vacuum pump, please open the gas vibration valve for a period of time (depending on the actual situation, generally about 1 hour);

Matters needing attention: Generally speaking, in the process of drug sublimation, when the powder enters the vacuum pump, it will have a great impact on the pump oil and the rotary vane of the vacuum pump. Therefore, pay attention to the effect of these conditions on the pump.