Vacuum pump refers to the device or equipment that uses mechanical, physical, chemical or physicochemical methods to extract air from the container to obtain vacuum. Generally speaking, vacuum pump is a device to improve, generate and maintain vacuum in a certain closed space by various methods.

一、 Check the preparation before starting

1. According to the working condition of vacuum pump, high quality calcium base grease and engine oil are used for lubrication respectively. If grease lubrication is used for vacuum pump, grease shall be added to bearing box regularly. If oil level is insufficient for pump with oil lubrication, sufficient oil shall be added.

2. Check whether the storage liquid in the vacuum pump shell is higher than the upper edge of the impeller. If not, the storage liquid can be directly injected into the pump body from the liquid filling port on the vacuum pump shell, and the operation should not be started when the liquid storage is insufficient, otherwise it can not work normally and the mechanical seal is easy to be damaged.

3. Check whether the rotating parts of the vacuum pump are jammed and bumped.

4. Check whether the nuts at the foot of the vacuum pump body and the joints are loose.

5. Check the coaxiality and parallelism of vacuum pump shaft and motor spindle.

6. Check whether there is air leakage in the inlet pipeline. If there is air leakage, try to eliminate it.

7. Open the valve of the suction line and slightly open the outlet control valve.

二、 Start up and operation

1. Inching the self-priming vacuum pump, pay attention to whether the rotation direction of the pump shaft is correct.

2. Pay attention to abnormal sound and vibration when rotating.

3. Pay attention to the readings of the pressure gauge and vacuum gauge. After starting, when the readings of the pressure gauge and vacuum gauge fluctuate for a period of time and the indication is stable, it indicates that the pump has been filled with liquid and enters into normal infusion operation.

4. Before the vacuum pump enters the normal infusion operation, that is, during the self-priming process, special attention should be paid to the water temperature rise in the vacuum pump. If the process is too long and the water temperature in the pump is too high, stop the pump and check the cause.

5. If the temperature of the liquid in the vacuum pump is too high to cause self-priming difficulty, the pump can be stopped temporarily, and the liquid in the discharge pipeline can be used to flow back into the pump or add a liquid storage port on the pump body to directly replenish liquid into the pump, so that the liquid in the pump can be cooled, and then start.

6. If there is strong vibration and noise in the working process of vacuum pump, it may be caused by cavitation of the pump. There are two reasons for cavitation: one is that the flow rate of inlet pipe is too high; the other is that the suction head is too high. When the flow rate is too high, the outlet control valve can be adjusted to increase the reading of the pressure gauge. If the inlet pipeline is blocked, it should be removed in time; if the suction head is too high, the installation height of the pump can be appropriately reduced.

7. When the vacuum pump stops for some reason during the working process and needs to be started again, the outlet control valve should be slightly opened (not fully closed), which is conducive to the discharge of gas from the outlet during the self-priming process, and can ensure that the tip can be started under a lighter responsibility.

8. Pay attention to check the pipeline system for leakage.

三、 Stop the pump

1. First, the gate valve on the discharge line must be closed.

2. Stop the vacuum pump.

3. In the cold season, the storage liquid in the slurry pump body and the water in the cooling chamber of the bearing body should be emptied to prevent the parts from cracking.