On the other hand, by separating gas and water into the impeller chamber and the water flow by about hole to return to the outer edge of the impeller. Backwater hole left back at the water pressure difference and gravity, fired channel impeller, the impeller was shattered, and inhalation of air pipes to a mixture, shuaixiang scroll to the rotation direction of flow. And then right to water in the backwater hole converging flow along the spiral flow. Due to the constant impact of the liquid in the case of the blade cascade, and constantly being crushed by the impeller, with the strong mixing of the air, the formation of a mixture of water and gas, and constantly flow so that the gas can not be separated from the water. The mixture was separated at the volute tongue export stripping along the short tube into the separation chamber. Isolated in the separation of indoor air discharged by an outlet pipe, and the water still flow by about backwater hole to the outer edge of the impeller, and mixed with the air suction pipe.
Since the height of self suction suction pump, and the impeller clearance before sealing, pump rpm, separation chamber liquid height and other factors. The smaller the impeller seal clearance, the greater the self suction height, generally take 0.3~0.5 mm; in the gap increases, in addition to the self suction height, the pump head and efficiency are reduced. The self suction height increases with impeller circumferential speed of U2 increases, but the maximum self suction height, the number increased to a high degree of self suction is no longer increased, but at this time to shorten the self-priming time; when the rotation decline, self-priming height decrease. In the case of other conditions unchanged, the height of the self absorption is also increased with the increase of the height of the water storage (but can not be more than the best reservoir water storage height). In order to better self-priming pump so that gas water mixture, the impeller blades to be less, so that the pitch of the cascade increases; and should adopt the semi open impeller (or impeller impeller channel wide), which is more convenient in depth into the backwater cascade of impeller.
