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Trouble shooting of abnormal sound of stainless steel multis
Source:未知|Popularity:0|release date:2020-04-20 16:27:08
Stainless steel multistage centrifugal pumps are machines for transporting or supercharging liquids. Now multistage centrifugal pumps represented by self-balancing structures have been widely used in industrial sectors such as mine drainage, chemical industry, petroleum, metallurgy, light industry, environmental protection, seawater desalination, and offshore oil production.
The safe and reliable operation of the water pump is closely related to the normal production activities of the enterprise and the development of the enterprise, so the maintenance and maintenance of the water pump are also crucial.
1. Failure of the stainless steel multistage centrifugal pump and the basic principles of troubleshooting
Common faults of water pumps are divided into mechanical faults and hydraulic faults. The pump is not running, the bearing is overheated is a mechanical failure; insufficient flow, cavitation, etc. are hydraulic failures.
When there is a fault, it should be eliminated in time, and the equipment must not be "sick" to work. The troubleshooting should follow the following principles: clarify the performance-analyze the cause-and eliminate it. The cause of the fault should be analyzed in various ways according to various situations, and strive to determine accurately.
2. Trouble shooting of abnormal sound of stainless steel multistage pump
The noise of the stainless steel multistage centrifugal pump during operation is abnormal or the operating noise is significantly increased. It has clearly reflected that a part of the equipment has failed, and it should be shut down for maintenance immediately to avoid serious accidents. The stainless steel multistage centrifugal pump will analyze the abnormal sound of the pump from two aspects, mechanical failure and hydraulic failure.
1) Mechanical failure
Most mechanical failures can cause abnormal sounds of stainless steel multistage centrifugal pumps. The following are common reasons: abnormal sounds caused by bearing wear, abnormal sounds caused by friction between the rotor parts of the pump and the casing, increased vibration caused by loose pump foundations, The sound of the pump shaft and the motor shaft are not concentric, and the sound of the pump parts is loose or falls off.
1.1 Bearing wear: Stainless steel multistage centrifugal pumps generally use a rolling bearing grease or thin oil lubrication structure. The water pump belongs to high-speed rotating equipment, and the bearing as the only support component has a very large amount of wear. It’s a common wearing part of stainless steel multistage centrifugal pumps. Therefore, in use, you should always pay attention to the temperature change of the bearing and add or replace lubricating grease in time to ensure a good working environment for the bearing.
1.2 The friction between the rotor parts of the water pump and the casing: the stainless steel multistage centrifugal pump does not contact between the casing and the rotor during normal operation. The casing and the rotor are only possible when the main shaft of the pump is bent, the rotor is unbalanced, and the amount of axial movement becomes large friction occurs. During shutdown maintenance, you can check whether the rotor and the casing are unevenly rotating or obviously scratched by means of barring. If necessary, the stainless steel multistage centrifugal pump needs to be disassembled and checked.
1.3 Vibration caused by loose pump foundation: During the long-term operation of the pump, due to the stress deformation of the pump base and the weak cement foundation, the problem of loose pump foundation will still occur, causing the sound of the pump to be abnormal and accompanied by There is severe shaking, and the tightening of the foundation bolts of the pump should be checked frequently during the daily maintenance of the pump.
1.4 The sound of the pump shaft and the motor shaft is abnormal: the high-speed rotating equipment has very high requirements on the concentricity of the prime mover and the follower. During installation, commissioning and maintenance, the concentricity check is a very important part through the dial gauge adjustment, control the run-out error within 10 wires.
1.5 Abnormal sound caused by loose or falling water pump parts: The common cause of this failure is that the positioning pin of the rotor is damaged due to too much torque. In addition, the shaft nut is loose due to the reverse rotation of the water pump or other reasons, and the axial size cannot Positioning.
2) Hydraulic failure:
The common reasons for the abnormal hydraulic failure of the stainless steel multistage centrifugal pump are the following two aspects: the cavitation of the pump and the gap in the pump are too large.
2.1 Water pump cavitation: When the flow rate of the liquid at the inlet of the impeller increases, and the pressure is lower than the corresponding saturation pressure of the working water temperature, it will cause a part of the liquid to evaporate. When the vaporized bubbles enter the area with higher pressure, the pressure suddenly condenses, so the surrounding liquid is replenished here, causing a hydraulic shock. The sound of cavitation is chaotic and irregular, with irregular sounds.
When the pump is running, close the pump outlet valve to determine whether the sound of the pump disappears. If the sound disappears after closing the valve, the pump cavitation can be basically determined. Generally, the way to increase the pressure at the inlet of the water pump is to solve the problem of cavitation, such as: reducing the installation height of the water pump, installing the front pump for the water pump, installing the induction wheel, and reducing the flow rate of the outlet when the pressure is insufficient Recirculation system, etc.
2.2 The gap in the pump is too large: the rotor parts of stainless steel multistage centrifugal pumps are vulnerable parts, especially when the inter-stage sealing unit is seriously worn due to long-term operation or long-term scouring of solid particles contained in the fluid medium, the gap increases, and the fluid medium moves from the high-pressure area to the low-pressure area serious leakage, increased fluid disturbance, and abnormal sound of the pump.
The increase of the internal gap of the pump will greatly change the flow head parameters, and the current parameters of the supporting motor will also change greatly. If such a fault occurs, the stainless steel multistage centrifugal pump should be disassembled and repaired, and the seal ring and guide vane sleeve should be replaced Sealed unit parts between grades.
The safe and reliable operation of the water pump is closely related to the normal production activities of the enterprise and the development of the enterprise, so the maintenance and maintenance of the water pump are also crucial.
1. Failure of the stainless steel multistage centrifugal pump and the basic principles of troubleshooting
Common faults of water pumps are divided into mechanical faults and hydraulic faults. The pump is not running, the bearing is overheated is a mechanical failure; insufficient flow, cavitation, etc. are hydraulic failures.
When there is a fault, it should be eliminated in time, and the equipment must not be "sick" to work. The troubleshooting should follow the following principles: clarify the performance-analyze the cause-and eliminate it. The cause of the fault should be analyzed in various ways according to various situations, and strive to determine accurately.
2. Trouble shooting of abnormal sound of stainless steel multistage pump
The noise of the stainless steel multistage centrifugal pump during operation is abnormal or the operating noise is significantly increased. It has clearly reflected that a part of the equipment has failed, and it should be shut down for maintenance immediately to avoid serious accidents. The stainless steel multistage centrifugal pump will analyze the abnormal sound of the pump from two aspects, mechanical failure and hydraulic failure.
1) Mechanical failure
Most mechanical failures can cause abnormal sounds of stainless steel multistage centrifugal pumps. The following are common reasons: abnormal sounds caused by bearing wear, abnormal sounds caused by friction between the rotor parts of the pump and the casing, increased vibration caused by loose pump foundations, The sound of the pump shaft and the motor shaft are not concentric, and the sound of the pump parts is loose or falls off.
1.1 Bearing wear: Stainless steel multistage centrifugal pumps generally use a rolling bearing grease or thin oil lubrication structure. The water pump belongs to high-speed rotating equipment, and the bearing as the only support component has a very large amount of wear. It’s a common wearing part of stainless steel multistage centrifugal pumps. Therefore, in use, you should always pay attention to the temperature change of the bearing and add or replace lubricating grease in time to ensure a good working environment for the bearing.
1.2 The friction between the rotor parts of the water pump and the casing: the stainless steel multistage centrifugal pump does not contact between the casing and the rotor during normal operation. The casing and the rotor are only possible when the main shaft of the pump is bent, the rotor is unbalanced, and the amount of axial movement becomes large friction occurs. During shutdown maintenance, you can check whether the rotor and the casing are unevenly rotating or obviously scratched by means of barring. If necessary, the stainless steel multistage centrifugal pump needs to be disassembled and checked.
1.3 Vibration caused by loose pump foundation: During the long-term operation of the pump, due to the stress deformation of the pump base and the weak cement foundation, the problem of loose pump foundation will still occur, causing the sound of the pump to be abnormal and accompanied by There is severe shaking, and the tightening of the foundation bolts of the pump should be checked frequently during the daily maintenance of the pump.
1.4 The sound of the pump shaft and the motor shaft is abnormal: the high-speed rotating equipment has very high requirements on the concentricity of the prime mover and the follower. During installation, commissioning and maintenance, the concentricity check is a very important part through the dial gauge adjustment, control the run-out error within 10 wires.
1.5 Abnormal sound caused by loose or falling water pump parts: The common cause of this failure is that the positioning pin of the rotor is damaged due to too much torque. In addition, the shaft nut is loose due to the reverse rotation of the water pump or other reasons, and the axial size cannot Positioning.
2) Hydraulic failure:
The common reasons for the abnormal hydraulic failure of the stainless steel multistage centrifugal pump are the following two aspects: the cavitation of the pump and the gap in the pump are too large.
2.1 Water pump cavitation: When the flow rate of the liquid at the inlet of the impeller increases, and the pressure is lower than the corresponding saturation pressure of the working water temperature, it will cause a part of the liquid to evaporate. When the vaporized bubbles enter the area with higher pressure, the pressure suddenly condenses, so the surrounding liquid is replenished here, causing a hydraulic shock. The sound of cavitation is chaotic and irregular, with irregular sounds.
When the pump is running, close the pump outlet valve to determine whether the sound of the pump disappears. If the sound disappears after closing the valve, the pump cavitation can be basically determined. Generally, the way to increase the pressure at the inlet of the water pump is to solve the problem of cavitation, such as: reducing the installation height of the water pump, installing the front pump for the water pump, installing the induction wheel, and reducing the flow rate of the outlet when the pressure is insufficient Recirculation system, etc.
2.2 The gap in the pump is too large: the rotor parts of stainless steel multistage centrifugal pumps are vulnerable parts, especially when the inter-stage sealing unit is seriously worn due to long-term operation or long-term scouring of solid particles contained in the fluid medium, the gap increases, and the fluid medium moves from the high-pressure area to the low-pressure area serious leakage, increased fluid disturbance, and abnormal sound of the pump.
The increase of the internal gap of the pump will greatly change the flow head parameters, and the current parameters of the supporting motor will also change greatly. If such a fault occurs, the stainless steel multistage centrifugal pump should be disassembled and repaired, and the seal ring and guide vane sleeve should be replaced Sealed unit parts between grades.