Measures to improve the self-priming performance of high-suction self-priming pumps:
(1) Increase the maximum circumferential speed of the impeller outlet and the outlet width of the impeller blades. The maximum circumferential speed of the impeller outlet can be realized by increasing the impeller speed directly by increasing the impeller speed. However, it is too large to ensure that increasing the maximum circumferential speed of the impeller outlet and the width of the impeller blade outlet will change the basic performance parameters of the pump such as flow rate and head. Therefore, the maximum circumferential speed of the impeller outlet and the outlet width of the impeller blades should be appropriately increased on the premise that the flow rate and head of the pump meet the requirements of use.
(2) Relationship between water storage capacity and self-priming performance: When the water storage capacity increases, the self-priming height of the pump is significantly increased, but when the water output is too large, the process of gas discharge is slowed down, that is, the self-priming time is increased. Therefore, when the self-priming height requirement is high but the self-priming time requirement is not too strict, the pump water storage capacity can be increased, and the high-suction self-priming pump increases the liquid storage chamber volume, but when the self-priming time is stricter. The size of the liquid storage chamber should be reasonably determined.
(3) Relationship between the area of the return hole and the self-priming time and the self-priming height: within the critical return hole area, when the area of the return hole increases, the self-priming time decreases, and the self-priming height decreases. Therefore, when the self-priming time is strict and the self-suction height is not high, the area of the return hole can be appropriately increased. Otherwise, the area of the return hole should be appropriately reduced.
(4) Setting the gas-liquid separation accelerating device can accelerate the gas-liquid separation, that is, the self-priming time can be shortened, and the simplest gas-liquid separation accelerating device is to add a baffle in the gas-liquid separation chamber. The addition of a baffle in the gas-liquid separation chamber has little effect on the self-priming height. Therefore, as long as the structure of the high-suction self-priming pump is allowed, a baffle should be provided in the gas-liquid separation chamber to accelerate the separation of gas and liquid and shorten the self-priming time.