Maintenance method of packing seal of explosion-proof multi-stage pump for mine
The maintenance method of the packing seal of the explosion-proof multi-stage pump for mining:
1. Clean the stuffing box of the explosion-proof multi-stage pump for mining, and check the shaft surface for scratches, burrs, etc. The stuffing box should be cleaned and the shaft surface should be smooth.
2. Check the shaft runout. The unbalance of the rotor runout should be within the allowable range to avoid excessive vibration, which is unfavorable to the packing.
3. Apply sealant or lubricant suitable for the medium in the stuffing box and the surface of the shaft.
4. For the packing packed in rolls, first take a wooden rod with the same size as the journal, wrap the packing on it, and then cut it with a knife. The edge of the knife is preferably 45° bevel.
5. The packing should be filled one by one, not several at a time. The method is to take a piece of packing, apply lubricant, hold one end of the packing interface with both hands, pull it apart in the axial direction to make it spiral, and then cover the journal through the incision. Do not pull apart in the radial direction to avoid uneven interfaces.
6. Take a metal bushing with the same size and material as the stuffing box or with a lower hardness than the shaft, push the packing into the deep part of the box, and apply a certain pressure to the bushing with the gland to pre-compress the packing. The pre-compression amount is 5%~10%, and the maximum is 20%. Rotate the shaft one more time and take out the shaft sleeve.
7. In the same way, fill the second and third roots. Note that when the number of packing is 4~8, the interfaces should be staggered by 90°; two packings should be staggered by 180°; 3-6 pieces should be staggered by 120° to prevent leakage through the interface.
8. After the last filler is filled, the gland should be used for compression, but the compression force should not be too large. At the same time, rotate the shaft by hand to make the assembly compression force tend to be distributed parabolic. Then slightly loosen the gland.
9. Carry out a running test. If it cannot be sealed, press some packing; if the heat is too great, relax it. It can be put into use only after it is adjusted to the point of dripping leakage and low heat generation (the temperature of the filling part can only be 30-40°C higher than the ambient temperature).
The installation of the packing seals of explosion-proof multi-stage pumps for mining shall meet the requirements of technical documents. If there is no regulation, the following requirements shall be met:
1, check the radial runout of the shaft at the sealing part, the allowable radial runout of the shaft is within the range of 0.03~0.08mm;
2. The diameter gap between the liquid seal ring and the shaft sleeve is generally 1.00~1.50mm, and the diameter gap between the liquid seal ring and the stuffing box is generally 0.15~0.20mm;
3. The diameter gap between the packing gland and the shaft sleeve is generally 0.75~1.00mm, and the surrounding gap should be uniform;
4, the diameter gap between the packing gland and the stuffing box is generally 0.10~0.30mm;
5. When there is a filler bottom ring, the diameter gap between the bottom ring and the shaft sleeve is generally 0.70~1.00mm;
6. After the packing is compressed, the liquid sealing ring inlet hole should be aligned with the liquid sealing tube, or the liquid sealing ring should be slightly to the outside;
7. For packing in rolls, first take a wooden stick with the same size as the shaft, wrap the packing on it, and then cut it with a knife. The incision is preferably 45° inclined.
