The high power and overload of centrifugal pumps seriously affect their service life. Centrifugal pumps work by using the rotation of impellers to cause centrifugal motion of water. Before starting the water pump, it is necessary to fill the pump casing and suction pipe with water, and then start the motor to drive the impeller and water to rotate at high speed. The water undergoes centrifugal motion and is thrown towards the outer edge of the impeller, flowing into the pressure water pipeline of the water pump through the flow channel of the snail shaped pump casing. The basic structure of a centrifugal pump consists of six parts: impeller, pump body, pump shaft, bearings, sealing ring, and packing box.
Analysis of the reasons for the increase in power consumption of centrifugal pumps:
1. The pump matching is unreasonable. The pressure and displacement of the modified or replaced pump have increased compared to the original pump, while the power of the electric motor is too small;
2. The outlet valve of the pump is opened too wide, the pump pressure is too low, the pump displacement exceeds the specified value on the nameplate too much, and deviates too much from the working point;
3. The packing is pressed too tightly;
4. The power supply voltage is too low and the current exceeds the rated value;
5. The motor or pump is severely misaligned and vibrates severely;
6. Severe friction between the rotor and stator components inside the pump;
7. The rotor of the electric motor moves and is not in the correct position, causing the journal step to rub against the end face of the bearing or the coupling to rub against the oil seal cover;
8. The buffer and shock-absorbing rubber ring of the coupling is too tight, causing the motor coupling to rub against the bearing cover due to the forward movement of the pump;
9. The pump balance plate did not open, resulting in severe grinding and overheating of the balance return pipe;
10. The radial clearance of the pressure relief sleeve or balance plate is too small, the deflection is too large, and it wears out during operation;
11. When the pump is started, serious internal faults occur, such as the detachment of the mouth ring and liner, or insufficient clearance in the fit;
12. The pump shaft has poor rigidity and is bent and deformed.
Most centrifugal pumps have a service life, but manufacturers rarely inform customers when purchasing. During use, the water pump equipment constantly operates, causing friction between the impeller and water, resulting in cavitation phenomena that constantly apply pressure and erosion to the overcurrent part of the pump body. The vibration of the motor and the long-term impact of audio, as well as the influence of the atmosphere
The rust on the iron surface increases with the increase of assembly clearance and motor power consumption, so we can consider purchasing a new water pump.
1. The service life of a centrifugal pump is generally five to seven years, and the mechanical seal can be replaced every one or two years. Depending on the frequency of use, it is recommended to replace the impeller of a pipeline pump every five years. If you hear a strong friction sound in the motor, you can replace the bearing, disassemble the pump, take out the bearing, and purchase the model on it.
2. Clean the centrifugal pump, which has a lifespan of four to five years. The pump components are more affected by cavitation, and the rubber seals inside need to be replaced as the pressure decreases. The lifespan of the hard plastic pump is three to five months, the connecting rod shaft is one year, and the motor is five years.
3. A multi-stage centrifugal pump is a type of water pump with a flow rate ranging from small to large and multiple models. The head ranges from more than 20 meters to more than 300 meters, and the motor ranges from 1.1 kilowatts to 160 kilowatts. The service life of a multi-stage pump is 5-8 years, and the main vulnerable parts are the plum blossom gasket and mechanical seal. Damaged plum blossom gaskets can be seen, and mechanical seal wear will cause water to flow out. In addition, some multi-stage centrifugal pumps are sealed with packing, and the water flow can be controlled with screw caps. It is best to seal with 6 drops of water per minute.
