1. Working principle of centrifugal pump
Before the water pump starts, fill the pump and the inlet pipe with water. After the water pump runs, under the action of centrifugal force generated by the high-speed rotation of the impeller, the water in the impeller channel is thrown around and pressed into the volute, the impeller inlet forms a vacuum, and the water in the pool is sucked along the suction pipe under the external atmospheric pressure to supplement this space. Then the inhaled water is thrown out by the impeller and enters the outlet pipe through the volute. It can be seen that if the centrifugal pump impeller rotates continuously, it can absorb and press water continuously, and the water can be continuously raised from low to high or far away. To sum up, centrifugal pump is called centrifugal pump because it lifts water to a high place under the action of centrifugal force generated by the high-speed rotation of impeller.
2. General characteristics of centrifugal pump
(1) The flow direction of water along the centrifugal pump is to suck in along the axial direction of the impeller and flow out perpendicular to the axial direction, that is, the inlet and outlet flow directions form 90 ° to each other.
(2) Since the centrifugal pump forms vacuum water absorption by the inlet of the impeller, it must be filled with water in the pump and the suction pipe before starting, or pumped with a vacuum pump to exhaust the air to form a vacuum. Moreover, the pump shell and the suction pipe must be strictly sealed without air leakage, otherwise there will be no vacuum and no water will be absorbed.
(3) Since it is impossible to form an absolute vacuum at the impeller inlet, the suction height of the centrifugal pump cannot exceed 10m. In addition, the actual allowable installation height (the height between the pump axis and the suction water surface) is far less than 10m due to the loss along the way caused by the water flow through the suction pipeline. If the installation is too high, it will not absorb water; In addition, since the atmospheric pressure in mountainous areas is lower than that in plain areas, when the same water pump is installed in mountainous areas, especially in mountainous areas, its installation height should be reduced, otherwise it can not suck water.
