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 the small butterfly valve, if the whole box is vacuumed, make sure that the box door and valve are closed. If only the rear box is vacuumed, make sure that the opening of the front box door is greater than 90 degrees, and pay attention to personnel safety.
2. Before the vacuum pump starts to vacuum the box, make sure that the rear box is dry. If there is water vapor, the condenser temperature must be lower than -45℃.
3. If the vacuum pump needs to be water-cooled, make sure that the cooling water is in place before the vacuum pump is turned on. During operation, you can touch the temperature of the pump body with your hand.
4. Check whether the pump can reach the limit vacuum within a normal time? Observe whether the vacuum pump produces noise when it is running? Whether the vacuum pump oil and the various connecting parts on the pump head are loose, etc.
5. Open the air vibration valve of the vacuum pump every week and run it for about 2 hours under no-load conditions; check whether the pump body leaks oil and whether there is 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 white turbidity composed of small white droplets appears on the upper part of the oil during operation, it means that water vapor or organic solvent has entered the vacuum pump. Please open the air vibration valve for a period of time (depending on the actual situation, generally about 1 hour);
Note: Generally speaking, the entry of drug powder into the vacuum pump during the sublimation process of drugs will have a great impact on the pump oil and the rotor of the vacuum pump. This can also happen when the vacuum pump is working with water or pollution. Therefore, pay attention to the impact of these situations on the pump.
