1、Impeller and front guard gap inspection and adjustment, generally between 0.75-1mm.
2、Adjustment of motor steering
The motor steering should ensure that the pump steering and the specified direction, not reverse rotation, otherwise cause impeller decoupling or damage to other parts.
Motor steering adjustment, should be in slurry pumps completely disconnected state (that is, not on the coupling pin or belt), in confirming the motor steering requirements before connecting with the pump, never allow blind start motor.
1、Starting of single-stage pump
① open the shaft seal water and cooling water.
② open the inlet valve completely.
③ open the water injection valve to the pump injection (backflow pump does not need water injection).
④Adjust the outlet valve opening to 1/4.
⑤ Start the unit. After the speed is normal, turn on the outlet pressure gauge, if the pressure temperature is normal, you can slowly open the outlet valve until it is fully opened or meet the working condition requirements.
Note: Starting the pump in the state of fully open the outlet valve will cause motor overload; using a small inlet valve to control the flow will cause pump cavitation, should be avoided.
2、Starting of tandem pump
Industrial sludge pump start when the pipeline is not full of slurry, if the valve is fully open, the pipeline head is very low, the instantaneous flow of the pump is biased towards the large flow, resulting in motor overload, or cause cavitation vibration of the pump, causing failure. Therefore, it is appropriate to start according to the following steps.
① close the export valve, fully open the import valve.
② open the shaft seal water and cooling water, the pressure will be adjusted to the specified value.
③ open the water injection valve to the pump injection (backflow pump open the inlet valve)
④ Start the first stage pump and gradually open the outlet valve to 1/i (i is the number of stages in series).
⑤ when it is estimated that the slurry is filled to 1/i pipeline, start the second stage pump and gradually open the outlet valve to 2/i.
⑥ When it is estimated that the slurry is filled to 2/i pipeline turn on the third stage pump and gradually open the outlet valve to 3/i.
⑦ the rest in turn, until the slurry is full of the entire pipeline operation is normal.
3、Matters that should be noted when starting Slurry pumps.
① Because the packing is pressed too tightly, when the pump starts, the packing is hot and smoking, the packing gland nut should be loosened to make the shaft seal water leak, and then slowly tighten until the drip seepage.
②Pump with water-injected mechanical seal, if there is no shaft seal water, static and dynamic ring dry friction, will instantly burn the mechanical seal, before starting should ensure that the shaft seal water supply is normal.
③After normal operation, the following items should be observed.
Is the shaft seal water supplied to the mechanical seal normal, mechanical seal temperature rise ≤ 35℃, the maximum temperature ≤ 75℃.
Whether the flow head (outlet and inlet pressure) of slurry pumps is stable and meets the process requirements; whether the current is stable; whether the unit has abnormal sound, whether the noise and vibration are too large, and whether the packing seal is suitable for the dripping without becoming a line.
4、Pump stopping precautions
①Pumping should be pumped for 30 minutes before stopping the pump to clean the pump and the slurry in the pipe.
②Close the export valve of the last stage pump.
③Stop the pump from the last pump to the first pump step by step, and close the corresponding shaft seal water and cooling water.
④Close the inlet valve of the first-stage pump.
Note: Never allow the export valve fully open state at the same time to stop all levels of the pump, otherwise it is easy to form water hammer, resulting in damage to the pump or pipe fittings.
5、Maintenance of Slurry pumps
(1) keep the equipment clean, dry, no oil, no leakage.
(2) daily checkpoint bracket oil level is appropriate, the correct oil level is near the oil level line position, not more than ± 2mm.
(3) often check whether the pump operation sound abnormal, vibration and leakage, and find the problem in time to deal with.
(4) Forbid the pump to run in the pumping state, because the pump running in the pumping state is not only violent vibration, but also affect the life of the pump, must pay special attention.
(5) The pump is strictly prohibited to enter metal objects and more than the pump allowed to pass the large solids, and strictly prohibited to enter the rubber, cotton, plastic cloth and other flexible objects, so as not to damage the overflow parts and block the impeller flow channel, so that the pump can not work properly.
(6) Check whether the pressure and flow of shaft seal water and cooling water are suitable, which can be done by checking the valve opening degree of shaft seal water pipe or detecting the temperature of stuffing box. For the pump with grease packing, it should be regularly refueled once or twice a day to ensure that the packing is in good lubrication condition.
(7) Regularly detect the leakage of shaft seal water, when the leakage increases, the bolts of packing gland should be adjusted, and the packing should be changed in time when needed.