Horizontal water pump heating method
When the pump transports medium above 200℃, the pump must be warmed up before driving, otherwise the medium entering the pump will cause the temperature in the horizontal water pump to increase instantaneously, the rotor parts will expand rapidly, and the static parts will be heated relatively lagging behind, resulting in the difference between the dynamic and static parts The gap between them is reduced, and mutual contact, friction or seizure may occur. In severe cases, the dynamic balance accuracy of the rotor will be destroyed, and the rotor may jam, which is often referred to as shaft holding. When transporting the medium that is easy to solidify, a heating pump must be used, otherwise the inlet and outlet pipes are easy to be blocked by the solidified medium, causing cavitation and vibration failure.
D-type multistage pump (6)
1. High temperature horizontal water pump heating method
(1) When the heating pump unit is started after trial or overhaul, the pump should be warmed up, that is, the pump inlet valve is slightly opened, and the medium flows from the pump suction port through the pump body and drains from the pump outlet pipeline to the designated collection. The device can also be called an intermittent heating pump (public number: pump housekeeper).
(2) Precautions The precautions for the high-temperature pump start-up heating pump are as follows:
1) The temperature rise rate of the heat pump is 15-30 ℃/h.
2) When the difference between the temperature of the pump body and the temperature of the conveying medium is ≤20℃, the warming pump can end.
3) After the warm-up period is over, close the heat pump pilot valve and start again when other driving conditions are met.
2. Spare horizontal water pump
(1) The OH2 structure standby pump heating pump causes a small amount of material to be drawn from the discharge pipe through the operating pump, flow through the pump body of the standby pump, and then return to the pump inlet, so that the standby pump is in a hot standby state, preventing the standby pump and suction and discharge pipes The internal medium is solidified to ensure that the heat pump is easy to start, which requires the use of reverse heating. That is to say, from the pump outlet pipeline shut off the valve after the heating pump line to the outlet check valve, a gate valve and orifice plate are set on the heating pump line, so that a small amount of material is led from the heating pump line through the main pump, and slowly flows through the pump body of the standby pump. Return to the pump inlet to achieve the purpose of continuous heating of the pump.
(2) BB2 structure standby pump heating pump BB2 structure pump, the way to warm the standby pump is to lead the pipeline from the pump outlet stop valve to the heating pump pipeline parallel to the pump discharge pipeline, the medium slowly flows back to the pump inlet, warm A gate valve and an orifice plate are set on the pump pipeline.
(3) Precautions The precautions for the standby pump heating pump are as follows:
1) The flow of the heating pump should not be too large, preferably 3% to 5% of the rated flow, to ensure that the standby pump will not reverse.
2) The heating pump valve must be closed after the standby pump is started.
3) The temperature rise rate of the heat pump ≤20℃/h.
4) The temperature difference between upper and lower pump body is ≤35℃.
5) When the temperature difference between the upper part of the pump body and the temperature of the conveying medium is ≤25℃, the standby pump can be started.
6) During the whole heating process, the standby pump is cranked once every half an hour, and the rotor rotates 180° and parked. If cranking is difficult, stop cranking and wait until the temperature continues to rise for a certain period of time.
7) According to the size of the pump outlet pressure, and according to the calculation of the medium characteristics, select the appropriate orifice plate. If a single-stage orifice plate cannot meet the requirements, a multi-stage orifice plate should be selected to prevent cavitation and cavitation.
8) When the operating pump is switched to the standby pump, the appeal step adjustment is also carried out on it, and it is adjusted until it is ready to be turned on again.
3. Other
If the temperature is lower than the freezing point of the material, a heating pump bypass is also required to prevent the material from solidifying in the pump body. In addition, an anti-condensation bypass is required between the pump inlet and outlet, connecting the pump outlet shut-off valve after the pump inlet shut-off valve When the standby pump is overhauled, close the shut-off valve at the inlet and outlet of the standby pump and open the anti-condensation line valve. A small amount of liquid flows slowly in the pump inlet pipe section to ensure that the fluid in the pipeline does not condense.
