The balance plate is used to balance the axial force of the horizontal pressurized multi-stage pump. The working fluid is liquid. The function of the balance plate of the D-type horizontal pressurized multi-stage pump is mainly to automatically balance the axial thrust.
Seven methods to reduce the wear and tear of the balance plate of a multi-stage pump:
1. Adopt a balance drum and balance plate combined device
There is no axial gap in the balance drum. The labyrinth seal/comb seal and the radial groove of the balance drum form a radial gap, which can play a better decompression effect. The high-pressure gas flows through the radial gap of the balance drum and enters the balance. The cavity then enters the balance pipe connected with the inlet, so that the pressure in the cavity is always equal to or slightly higher than the inlet pressure to achieve the purpose of balancing the axial force.
2. Choose wear-resistant materials
The multi-stage pump has a large number of stages, a relatively slender shaft, and a large static deflection. It is easy to collide between the rotor and the fixed parts, resulting in unstable operation, increased vibration and noise, and premature damage to vulnerable parts. In order to overcome this defect, we require manufacturers to increase the design size of the spindle on the basis of the original design, so that the rigidity of the spindle is greatly strengthened and the operation is more stable.
3. Reduce the impurities in the conveying medium
Frequently clean the sedimentation tank or sump and filter screen to minimize the content of impurities in the conveying medium. According to the characteristics of the conveyed medium, wear-resistant, corrosion-resistant and friction-reducing coatings are adopted for the bonding surface of the balance disc and the balance ring of the multi-stage pump, and measures to reduce the balance return water resistance are adopted to effectively reduce the chamber. Pressure greatly improves the reliability of the shaft seal and reduces leakage.
4. Balance the water pipe
The D-type horizontal pressurizing multi-stage pump balances the axial force by the balance mechanism in the pump, and the balance liquid flows out from the balance device. The balance liquid is connected to the suction section by the balance water pipe, or a short pipe is designed outside the balance. The pipe flows out of the pump. To ensure the normal operation of the pump, the balance water pipe must never be blocked.
5. Avoid cavitation
During the operation of the pump, it is necessary to ensure a sufficiently high water level to avoid excessive water absorption, which can not only avoid cavitation, but also improve the efficiency of the pump.
6. The method of pre-tightening assembly
In view of the long-term unsolved problem of the guide vane sleeve being out of stock rotation or micro-swing in the middle section of the D-type horizontal pressurized multi-stage pump, we adopted the pre-tightening assembly method to completely solve it, reducing the vibration and noise of the pump, and making The pump runs more smoothly and quietly.
7. Strengthen the management of operation and maintenance, and strictly implement the operation
Procedure start: Before the pump is started, the pump rotor should be rotated to check whether the rotor is flexible; open the pump suction valve, close the pump outlet pipeline gate valve and pressure gauge cock, make the pump full of liquid, or use a vacuum system to remove the suction pipe and the air in the pump; Start the motor. After the pump runs normally, open the pressure gauge cock and slowly open the pump outlet gate valve until the pressure gauge pointer points to the required pressure.
Operation: During the operation, you must pay attention to the observation of the meter readings, whether the bearing heating, filling water leakage and heating, and the vibration and sound of the pump are normal. If abnormal conditions are found, they should be dealt with in time; the change in bearing temperature reflects the assembly quality of the pump. The temperature rise of the bearing should not be higher than the ambient temperature of 35℃, and the maximum temperature of the bearing should not be higher than 75℃; there is a certain axial movement of the pump rotor during operation, and the axial movement should be within the allowable range. It should be ensured that the motor and the pump are both The clearance value of the coupling end face; the impeller, sealing ring, guide vane sleeve, shaft sleeve, flat surface should be checked regularly during the operation of the pump.
The wear and tear of parts such as the weighing plate should be replaced in time when the wear is too large
Stop: Before stopping, close the pressure gauge cock, slowly close the outlet gate valve, and stop the motor after the outlet network is closed, and then close the suction network of the pump after the pump has stopped.
The reason why the balance plate of the D-type horizontal booster multistage pump can balance the axial thrust depends on the pressure difference between the two sides of the centrifugal pump balance plate, and can automatically maintain the gap between the balance plate and the balance seat. This pressure difference produces a balance between the balance force and the axial thrust, which is also the common principle of balancing the axial force of the balance disc of the domestic multi-stage centrifugal pump.
