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2, completely open the outlet valve, pressure gauge, drain the pump air, a flexible disk drive coupling.
3, in accordance with the original rules, open the inlet valve, circulating valve , the pump starts to open the outlet valve. This method of start-up has a major drawback. First, the balance disc and balance ring of the pump are designed to the rated outlet pressure of the pump (lift of 550 m). When the open cycle valve, the pump outlet pressure of 3-4MPa, due to the axial force, the rotor to the inlet section of the export section of the series, increasing the balance disc wear. In fact, if the outlet pressure of the pump exceeds the rated value, it can also push the balance disc and the balance ring. The liquid flows into the pump inlet through the balance pipe. The balance disc and the balance ring establish a new balance. Therefore, you can not open the recirculation valve when starting the pump.
4, the pump starts juxtaposed, check the vibration, abnormal noise, pressure, seal, current value, bearing temperature, non-pump at high flow and low lift parameters of the operation.
5, stop the pump, close the inlet pressure gauge, outlet pressure gauge, slowly shut down the outlet valve to stop the pump, off the inlet valve.
Second, the use of pump inspection and inspection 1, check the pump vibration, vertical must ≤ μm, horizontal ≤ μm.
2, packing seal leaking 20-30 drops / minute is appropriate to maintain the normal lubrication and cooling sleeve and packing. Check especially pay attention to the water leakage can not exceed 20-30 drops / minute, because the wind direction of the motor is blown from the water inlet to the water end, although the shaft has a retaining ring, but also can not avoid water along the axial Bearing chamber, affecting bearing life.
3, bearing temperature not higher than 70 ℃.
4, abnormal sound check. Abnormal sound mainly from the impeller and the friction ring mouth, when the balance of the air disk and the balance ring friction, bearing damage to the deregulation of the coupling deformation, elastic ring damage, hear a continuous sound to stop pumping immediately check.
5, the pressure and current checks. Pressure and current swing, which means the flow changes, or mechanical and electrical failure (pressure 5.3-5.5MPa, current 170-180A, when the current is greater than 190A, the mechanical and electrical failures may occur)
6, coupling clearance check. Coupling to maintain 5-7mm gap, when the gap is small or not, the axial force will make the motor bearing temperature rise, burn the motor bearings, this time should stop the pump check the balance disc.
Third, the pump maintenance 1, pumps and motors at the same time the anchor bolts and pouring, non-secondary grouting. ,
2, the pump body in addition to withstand the preload flange bolts, do not bear any external stress.
3, pump disassembly and assembly. The disassembly sequence is the pump outlet to the inlet.
4, parts cleaning kerosene.
5, parts inspection in strict accordance with the standards:
Beats both ends less than 0.02mm, the middle beat less than 0.05mm.
The impeller and the mouth ring gap of 0.3-0.4mm, the gap exceeds the maximum half (ie 0.6mm), the non-use.
Impeller inlet external beating less than 0.06mm-0.08mm.
Balance disc outer beat less than 0.06mm, Balance disc end beat less than 0.04mm
The radial clearance between the balance disc and the balance ring is between 0.4-0.8mm.
6, the adjustment of the amount of string The adjustment of the amount of water pump repair is the most critical part of the author that the theoretical amount of the pump assembly is not installed after the balance plate, the rotor into the suction side, the impeller ring close to the ring seal , Then the center of the impeller and guide vane should be aligned, the distance from the impeller suction side to the guide vane. If the guide vane center and the impeller can completely coincide, the highest efficiency, head loss minimum.
In the actual maintenance, it is inevitable to replace all or part of the impeller, the mouth ring and the guide vane. Due to the manufacturing error, the original string movement can not be guaranteed and needs to be readjusted. The method is to first measure the impeller at the inlet and the middle of the first stage, and use it as a benchmark to measure the maximum quantity of each impeller one by one. If the value is slightly larger than the water inlet, it can be regarded as Qualified, less than the water section must be adjusted. Under normal circumstances, is to take the middle of the pad or adjust the middle section of the export to be adjusted.
Use and maintenance of boiler feed pumps
First, the water pump to start 1, DG-type pump in our plant using the medium temperature of 102 ℃ -104 ℃, before starting the pump body temperature should be noted that the temperature should be maintained at or near the medium temperature, and only when the temperature rose to the same or similar medium temperature When it can start to pump into operation.