In the process of use, improper operation will increase the working intensity of the vacuum pump current, which will cause motor overload after a long time. There are many factors affecting the current and various solutions. This paper discusses the causes and preventive measures for several common phenomena.
From the perspective of technology, there are several reasons:
It is recommended to eliminate the external causes carefully first, because the disassembly of the vacuum pump is rather cumbersome. If it is the problem of vacuum pump itself, it is recommended to find the manufacturer for specific communication.
1. Vacuum pump sealing liquid density is large.
2. The sealing liquid temperature of positive air pump is high, and part of it is vaporized.
3. The suction load of vacuum pump is high and the exhaust pressure is too high.
4. The shaft seal of the vacuum pump is broken and has great friction.
5. There is a problem with the motor itself.
6. The suction medium contains high viscosity material, which increases the friction between impeller and liquid ring.
In the ordinary enterprise production, the power required by the vacuum pump to compress the gas is directly proportional to the pressure difference. Once the gas pressure difference is too high, the vacuum pump may be overloaded, causing the motor winding burning. How can we prevent the overload of vacuum pump?
1. Adopt mechanical automatic pressure regulating bypass valve:
The bypass valve is installed on the bypass pipe between its outlet and inlet. This valve controls the pressure difference between the inlet and outlet of the vacuum pump not to exceed the rated value. When the pressure difference reaches the rated value, the valve automatically opens by the action of the pressure difference, so that the outlet and inlet of the vacuum pump are connected, so that the pressure difference between the inlet and the outlet is rapidly reduced, at this time, the pump works under almost no pressure difference load. When the pressure difference is lower than the rated value, the valve will close automatically, and the gas will be pumped out by the front stage pump through the vacuum pump. The bypass overflow valve can be started at the same time with the front pump, which makes the operation of the unit simple and convenient.
2. Adopt hydraulic coupling:
The use of hydraulic coupling can also prevent the overload of the pump, so that the vacuum pump can work under high pressure difference. The hydraulic coupling is installed between the vacuum pump and the motor. Under normal working condition, the hydraulic coupling transmits rated torque from the motor end to the pump. The maximum pressure difference of vacuum pump is determined by the maximum torque transmitted by the hydraulic coupling, and the maximum torque transmitted by the hydraulic coupling is regulated by the amount of liquid in it. When the pump works under high pressure difference or starts at the same time with the front pump, there is a speed difference in the liquid coupling, i.e. sliding, which only transmits a certain moment to slow down the pump. With the progress of air extraction, the gas load is reduced and gradually accelerated to the rated speed.
3. Vacuum electrical elements are used to control the pump inlet pressure:
Install pressure sensitive elements such as vacuum capsule relay or electric contact vacuum pressure gauge at the inlet pipeline of vacuum pump. After the vacuum system is started, when the pressure at the pump inlet is lower than the given value, the pressure sensitive element sends a signal to start the pump through the electrical control system. If the pressure at the pump inlet is higher than the specified value, the pump will be shut down automatically, thus ensuring the reliable operation of the pump.
For the above vacuum pump overload prevention measures, I believe that you will reduce the loss in the future use, and more conducive to our use. Prolong the service life of vacuum pump.