How to maintain and service slurry pump？

The maintenance of slurry pumps is a matter that must be paid attention to in the application of slurry pumps. In order to ensure the safe and reliable operation of slurry pumps and give full play to the efficiency of equipment, it is very important to carry out daily maintenance and adopt correct maintenance and disassembly methods. Therefore, according to the characteristics of slurry pumps, we put forward the following maintenance and maintenance suggestions.

 

 

• Daily care and maintenance

 

 

1. Keep the equipment clean, dry, oil-free and leak-free.

2. Check the oil level in the bracket every day. The correct oil level is near the oil level line and should not exceed ±2mm.

3. Check the pump frequently to see if there are any abnormal sounds, vibrations or leaks during operation. If any problems are found, deal with them promptly.

4. It is strictly forbidden to operate the pump in an evacuated state, because the pump will not only vibrate violently when it is evacuated, but will also affect the life of the pump. Special attention must be paid.

5. It is strictly forbidden to enter metal objects and large solids that exceed the allowable passage of the pump, and it is strictly forbidden to enter flexible materials such as rubber, cotton, and plastic cloth, so as not to damage the flow components and block the impeller flow channel, causing the pump to fail to work normally.

6. Check the pressure and flow of the shaft seal water and cooling water frequently to see if they are appropriate. You can check the opening degree of the shaft seal water pipe valve or detect the temperature of the stuffing box. When the temperature is high, it means that the water supply is insufficient. For pumps that use grease to lubricate the stuffing, oil should be added regularly once or twice a day to ensure that the stuffing is in a good lubrication state.

7. Check the leakage of the shaft seal water regularly. When the leakage increases, adjust the bolts of the packing gland. If the packing needs to be replaced, do so in time.

 

 

8. It is recommended to use carbon fiber impregnated with polytetrafluoroethylene or cotton thread boiled in butter. When the working pressure is not greater than 0.5 MPa, asbestos packing can be used.

The packing filling method should be filled in strict accordance with the following requirements:

(1) The packing length is determined by the circumferential length of the sleeve. When filling each ring, the cuts should be staggered by 1200.

(2) After filling, it is necessary to conduct a water test run. During operation, adjust the gland bolts in detail to achieve the best state of leakage in points and not in lines. Packing filling is very important. It is not only related to the sealing state, but also affects the performance of the pump. It should be paid enough attention.

9. In order to ensure the efficient operation of the pump, it is necessary to regularly adjust the gap between the impeller and the front guard plate (after a period of use, when the operating conditions remain unchanged and the current slowly decreases) to keep it between 0.75-1.00mm.

The adjustment steps are as follows:

(1) For pumps with split brackets

The gap between the impeller and the front guard is 0.75-1.00mm, which is usually adjusted before leaving the factory. If it is found that this gap does not meet the requirements, it should be adjusted. If problems are found during operation, the machine should be stopped for adjustment.

The pump with split brackets should be adjusted as follows:

① Loosen the bracket cover clamping nut;

② Loosen the bearing box adjustment screw;

③ Evenly tighten the bearing box clamping nut to move the rotor assembly toward the pump head, and turn the wheel while tightening until it stops. Note that the wheel should be in accordance with the pump's working direction.

④ Use a feeler gauge to measure the gap δ=a between the bearing box flange and the bracket end face; at this time, the gap between the impeller and the front guard is 0.

⑤ Loosen the bearing box clamping nut;

⑥ Tighten the bearing box adjustment screws evenly to move the rotor assembly toward the motor, and use a feeler gauge to check the gap until δ = a + (0.75-1.00) mm (the larger value is used for large pumps). Note that the gap should be uniform;

⑦ Tighten the bearing box clamping nut to completely fix the axial position of the rotor.

(2) For pumps with a barrel bracket (see 16b in Figure 1)

The gap between the impeller and the front guard should be 0.75-1.00 mm, which is generally adjusted before leaving the factory. If it is found that this gap does not meet the requirements, it should be adjusted as follows:

① Loosen the bracket pressure plate nut;

② Adjust the screw to move the rotor forward, while adjusting and turning the wheel until it stops, and pay attention to the direction of turning the wheel is consistent with the direction of the pump;

③ Use a stylus to mark a straight line at the joint of the bracket and the cylinder as a mark;

④ Adjust the screw nut to move the rotor backward 0.75-1.00mm after assembly (the larger value is used for large pumps), and lock the adjustment nut to fix the axial position of the rotor;

⑤ Tighten the bracket pressure plate nut.

10. Frequently check that the maximum bearing temperature shall not exceed 75℃.

11. The lubricating oil should be completely replaced once the pump has been running continuously for 800 hours.

12. The standby pump should be rotated 1/4 turn per week to allow the shaft to evenly bear the static load and local vibration.

13. If the downtime is long, the sediment in the pump should be flushed with backwash water before restarting.

14. Check the looseness of the supporting mechanism of the inlet and outlet pipe system frequently to ensure that the support is firm and the pump body is not subject to support force.

15. Check the fastening of the pump on the foundation frequently, and the connection should be firm and reliable.

16. Special attention: For newly installed pumps after overhaul, be sure to test the direction of the motor before putting on the coupling pin. Use belt drive, that is, after testing the direction, install the drive belt, and never drive the pump to reverse. However, it is allowed that when the motor is powered off, the liquid in the pipe flows back to reverse the pump. However, it should be noted that when the height difference is particularly large (≥80m), the backflow of backwater should also be prevented to control the sudden reversal of the pump.

17. Before starting the pump, the shaft seal water and cooling water should be turned on first, and then the pump; after stopping the pump, the shaft seal water and cooling water can be turned off after 15 minutes.