Under normal circumstances, the self priming pump can completely self-prime normally, and the effect is very good. However, the self-priming ability may be reduced during the specific operation. It is not necessarily the failure of the self priming pump. Other factors are also Can cause the pump body to reduce its self-priming ability. This article will introduce in detail the factors affecting the self-priming performance of self-priming pumps.
1. The influence of ribs in the gas-water separation chamber on the self-priming time
Under the conditions of selecting the position of the return hole, the height of the liquid storage and the water storage tongue, the self-priming height can reach 7.5 meters without the ribs, but once the effective time of self-priming is exceeded or the self-priming time is lengthened, Then after adding the ribs, the self-priming time becomes 170 seconds, and the effect of the ribs directly improves the effect of air-water separation, thereby affecting the self-priming performance of the self priming pump.
2. The influence of the position of the return hole on the self-priming capacity
When the water storage height inside the self priming pump increases to 80 mm, the position of the return hole will be changed. At this time, the position of the return hole has a different maximum vacuum. When the distance of the return hole is 300, the self-priming height It is about 7.5 meters of water column, the self-priming height of 7.1 meters from the tongue 1200, the self-priming height of 6.8 meters of water column at 2100. Therefore, at 30 degrees of the backflow hole, the retention speed in the pump body is the fastest and the pressure is the smallest. The open backflow hole is closely connected with the outlet, which is most conducive to high-pressure water backflow, and the radial backflow impacts the blades. The gas and water are mixed.
3. The influence of water storage capacity and water storage height on self-priming performance
In the case of other conditions that affect the self-priming capacity of the self-priming pump, if the water storage height is too high, the self-priming height will also increase to about 6.8 meters, so the water storage height greatly affects the self-priming pump performance Self-priming ability.
4. Turning of the rear cover of the self priming pump impeller
For the external mixing centrifugal self-priming pump, when the speed of the outer circle of the impeller is less than that, the self-priming effect is poor. The method of turning the back cover of the impeller can be used to improve the self-priming ability. The reason is that it is easy to mix liquid and gas in the self-priming process. . The turning amount should not be too large, otherwise the lift and efficiency of the pump will be significantly reduced. At that time, the diameter of the rear cover of the impeller was cut; at that time, the upper septum was reinforced to prevent the liquid with bubbles from circulating at the cut back cover and affect the self-priming effect.