The analysis of the cause of the vibration of the pump causes many vibrations in the building and the pump house. There are some factors that are related and interact with each other. There are four main reasons for the summary.
1, electrical aspects
The motor is the main equipment of the unit, the internal magnetic imbalance of the motor and the misalignment of other electrical systems often cause submersible pumps.
Vibration and noise. For example, if the asynchronous motor is in operation, the radial alternating magnetic tension between the stator and rotor generated by the interaction of the stator and rotor harmonic flux, or the large synchronous motor is in operation, the stator and rotor magnetic forces are inconsistent or the air gap difference exceeds in all directions. Allowable deviation values, etc., may cause the motor to periodically vibrate and make noise.
2, mechanical aspects
Motor and water pump rotating parts are unbalanced, rough, poorly installed, the unit axis is asymmetrical, the pendulum exceeds the allowable value, the mechanical strength and rigidity of the parts are poor, the bearing and sealing parts are worn and damaged, and the critical speed of the pump appears with the unit. Resonances such as the natural frequency always cause strong vibration and noise.
3. Hydraulic aspects
Pump inlet flow rate and pressure distribution are uneven, pressure pulsation, liquid flow, bias flow and de-flow of pump inlet and outlet working fluids, non-fixed working conditions and pump cavitation caused by various reasons are common causes of pump unit vibration. s reason. Pumps and units generate vibrations due to sudden changes in pressure in the water pipeline and water hammer caused by dynamic transitions such as pump start-up and shutdown, valve opening and closing, operating conditions, and emergency shutdown.
4. Hydraulics and other aspects
The design of the inlet flow passage of the unit is unreasonable or not compatible with the unit, the pump is not deeply submerged, and the unit starts the pump control valve.
And the unscheduled sequence of shutdown will deteriorate the influent conditions, create vortices, induce cavitation or aggravate the vibration of the unit and pump room. When the unit that destroys the siphon vacuum cut-off is started, if the air in the hump section is difficult, the siphoning time is too long; the design of the unit flapping the door is unreasonable, and when the door is opened, the door is closed, and the door is constantly struck; The base of the pump and the motor is unevenly subsided or the rigidity of the foundation is poor, which also causes the unit to vibrate.