Abstract: A device of a volute channel of a pump is contained in a circular casing and cooperates a rotational impeller for pumping and delivering fluid. The device comprises a volute channel structure and a throat partition. The volute channel structure is a spiral volute channel and surrounds an impeller exit side. A leading edge of the volute channel is a water-cut angle. A sectional area of the volute channel is wider and deeper from the water-cut angle. An outer diameter of the volute channel is a concentric arrangement. The throat partition connects to a rear edge of the volute channel and extends toward an exit of the casing so as to that the throat partition is at least and mainly an extension of the volute channel; the extension of the volute channel overlaps the leading edge of the volute channel to have the total length of the volute channel, the total length is able to surround the impeller exit side over 360 degrees.

Abstract: A device of a volute channel of a pump is contained in a circular casing and cooperates a rotational impeller for pumping and delivering fluid. The device comprises a volute channel structure and a throat partition. The volute channel structure is a spiral volute channel and surrounds an impeller exit side. A leading edge of the volute channel is a water-cut angle. A sectional area of the volute channel is wider and deeper from the water-cut angle. An outer diameter of the volute channel is a concentric arrangement. The throat partition connects to a rear edge of the volute channel and extends toward an exit of the casing so as to that the throat partition is at least and mainly an extension of the volute channel; the extension of the volute channel overlaps the leading edge of the volute channel to have the total length of the volute channel, the total length is able to surround the impeller exit side over 360 degrees.

Abstract: The present invention is an improved structure for an oxygen adding and aeration device includes a pump; a two-layer impeller, which is installed on a top of the pump; a pump case, which covers on outside of the two-layer impeller; an air tube, which is installed in impeller inlets of a lower-layer impeller of the two-layer impeller, a top end of the air tube protrudes out of a water level; when starting the pump, the two-layer impeller is then driven to deliver air from the air tube into the lower-layer impeller, partial water is sucked from filter holes into air tube to mix with air becoming an air-water flow, continuously, the air-water injection flow is injected by the lower-layer impeller and the lower-layer outlet of the pump case to form an air-water injection flow, other partial water is sucked from the impeller inlet of the upper-layer impeller into the air tube, continuously, the water passes through the impeller outlet of the upper-layer and the upper-layer outlet of the pump case to form a water i