QHZP series self-priming pump

QHZP series self-priming pumpIt belongs to self-priming centrifugal pump, which has the advantages of compact structure, easy operation, stable operation, easy maintenance, high efficiency, long service life, and strong self-priming ability. There is no need to install a bottom valve in the pipeline. Before operation, it is only necessary to ensure that a certain amount of liquid is stored in the pump body. Different liquids can use self-priming pumps made of different materials.

The working principle of a self-priming pump is to fill the pump casing with water (or the pump casing itself with water) before starting the pump. After starting, the high-speed rotation of the impeller causes the water flow in the impeller channel to flow towards the vortex shell. At this time, a vacuum is formed at the inlet, causing the inlet check valve to open, and the air in the suction pipe to enter the pump and reach the outer edge through the impeller channel.

QHZP series self-priming pumpstructure

The structure of a self-priming pump flows in the direction of rotation. Then it merges with the water flowing from the right return hole and flows along the snail shell. Due to the continuous impact of the liquid on the blades inside the snail shell, it is constantly shattered by the impeller and strongly mixed with the air, generating a mixture of gas and water that flows continuously and cannot be separated. The mixture is stripped off by the tongue at the outlet of the snail shell and enters the separation chamber along the short tube. The air in the separation chamber is separated and discharged through the outlet pipe, while the water still flows towards the outer edge of the impeller through the left and right return holes and mixes with the air in the suction pipe. Repeat this process repeatedly, gradually exhausting the air in the suction pipeline and allowing water to enter the pump, completing the self-priming process.

The self-priming height of a self-priming pump is related to factors such as the sealing gap in front of the impeller, the pump speed, and the liquid level in the separation chamber. The smaller the sealing gap in front of the impeller, the greater the self-priming height, generally taken as 0.3~0.5 millimeters; When the gap increases, except for the decrease in self-priming height, the pump's head and efficiency also decrease. The self-priming height of the pump increases with the increase of the circumferential velocity u2 of the impeller, but when it reaches the self-priming height, the number of revolutions increases and the self-priming height no longer increases. At this point, only the self-priming time is shortened; When the rotation speed decreases, the self-priming height decreases accordingly. Under other constant conditions, the self-priming height also increases with the increase of water storage height (but cannot exceed the water storage height of the separation chamber). In order to better mix air and water in a self-priming pump, the number of blades on the impeller should be reduced to increase the pitch of the blade array; It is also advisable to use semi open impellers (or impellers with wider impeller channels), which makes it easier for the return water to penetrate deeply into the impeller cascade.