（1） Correction of vacuum pump
In order to avoid any doubt during the operation of vacuum pump, this paper introduces how to modify the vacuum pump: the corrosion shape of vacuum pump can be divided into full (uniform) corrosion and partial corrosion. The former occurs evenly on the surface of vacuum pump, while the latter only occurs in the parts, such as hole corrosion, crevice corrosion, intergranular corrosion, stress corrosion, etc. It is one of the most effective anticorrosive methods to choose polymer composite materials for the external organic coating of vacuum pump. It has outstanding chemical resistance function, excellent mechanical function and bonding function. Compared with the traditional pressure vessel welding and repairing, it has the characteristics of simple construction, low cost, safety function and good correction function.
（2） Scaling and cleaning of vacuum pump
During the operation of vacuum pump, scaling will occur due to technical water, calcium and magnesium hardness, pH value, conductivity, total alkalinity, temperature and other factors, and then constitute the following damage:
1. Increase the consumption and pollution load of chemicals;
2. Constitute production event and reduce equipment life;
3. Increase the number of unscheduled shutdowns to form continuous production and affect the production power of the equipment. Shut down the machine for cleaning, increase the repair cost and rated working load;
4. Increase energy loss. The traditional methods include chemical cleaning, high-pressure water cleaning, scale inhibitor adding, mechanical cleaning, disassembly and replacement, but they are time-consuming and laborious, and the effect of correction is not ideal.
Vacuum pump maintenance guide:
1. Check whether the vacuum pump pipeline and joint are loose. Turn the vacuum pump by hand to see if it is flexible.
2. Add bearing lubricating oil into the bearing body, observe that the oil level should be at the center line of the oil mark, and the lubricating oil should be replaced or supplemented in time.
3. Screw out the water plug of the vacuum pump body, and fill the water or slurry.
4. Close the gate valve, outlet pressure gauge and inlet vacuum gauge of the outlet pipe.
5. Jog the motor, and try to see if the rotation direction of the motor is correct.
6. Start the motor. When the vacuum pump is in normal operation, open the outlet pressure gauge and the inlet vacuum pump. Gradually open the gate valve and check the motor load after the appropriate pressure is displayed.
7. Try to control the flow and head of the vacuum pump within the range indicated on the label to ensure that the vacuum pump operates at the highest efficiency point, so as to achieve the maximum energy saving effect.
8. During the operation of vacuum pump, the bearing temperature shall not exceed the ambient temperature by 35 ℃, and the maximum temperature shall not exceed 80 ℃.
9. If any abnormal sound is found in the oil vacuum pump, stop the pump immediately to check the cause.
10. To stop using the vacuum pump, first close the gate valve and pressure gauge, and then stop the motor.
11. The lubricating oil of the vacuum pump shall be changed within 100 hours in the first month of operation, and then every 500 hours.
12. The packing gland shall be adjusted frequently to ensure the normal leakage in the packing chamber, and it is better to leak out in drops.
13. Regularly check the wear condition of the shaft sleeve, and replace it in time when the wear is large.
14. When the vacuum pump is used in the cold winter season, it is necessary to unscrew the drain plug at the lower part of the pump body to drain the medium after the pump is stopped. Prevent frost cracking.
15. When the vacuum pump is out of service for a long time, it is necessary to disassemble the pump completely, dry the water, coat the rotating parts and joints with grease, and properly store them.