JPS6017292A - Self-priming centrifugal pump - Google Patents

Abstract

PURPOSE:To reduce the dimension of a gas-water separating chamber and improve the pumping efficiency by installing a rectifying wall which suspends onto the upper wall of the returned-water passage of the gas-water separating chamber and preventing the reduction of the self-priming efficiency in the case when the dimension of the gas-water separating chamber is reduced. CONSTITUTION:The flow of gas foams is cut-off by a rectifying wall 14 installed so as to suspend onto a part of the upper wall 13 of a return-water passage 7 installed in a gas-water separating chamber 9. The returned water from which gas foams are removed is introduced into an annular flow hole 8, passing through the lower part of the rectifying wall 14. Therefore, the rectifying wall 14 serves for separating gas from water during the selt-priming operation by the use of priming, and said rectifying wall 14 serves as the resistance in the returned- water passage 7 when the normal pumping operation is performed, and thus a self-priming centrifugal pump having a high pumping efficiency which does not require the returned water can be obtained. Since the reduction of the self-priming effieciency in the case when the dimension of the gas-water separating chamber is reduced is prevented, the dimension of the gas-water separating chamber can be reduced, and the pumping efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a self-priming centrifugal pump having a steam/water separation chamber.

Conventional structure and its problems In general, a self-priming centrifugal pump consists of a pump case 1, a casing 2, and a casing cover 3, as shown in Figs. An impeller 4 is provided, a nozzle 6 is interposed between the casing 2 and the casing cover 3, and a volute chamber 6 and a return water passage T are formed together with the casing 2 and a part of the casing cover 3. A circulation hole 8 leading from the passage 7 to the volute chamber 6 is provided. In the figure, 9 is a steam/water separation chamber, 1o is a suction port, and 11 is a discharge port.

In the above configuration, when the inside of the pump case 1 is filled with water by priming and the impeller 4 rotates, the pump performs a self-priming action. At this time, the steam and water mixed water discharged from the volute chamber 6 is separated in the steam and water separation chamber 9, and the returned water is
The water flows through the return water passage 7 and returns to the volute chamber 6 through the circulation hole 8 provided on the front side of the impeller in the volute chamber 60. If the steam/water separation chamber 9 is made smaller here, the return water containing many bubbles will return to the volute chamber 6 through the above-mentioned path with insufficient steam/water separation, resulting in a decrease in self-priming efficiency. On the other hand, if the air-water separation chamber 9 is made smaller, the overall size of the device becomes larger, which causes a problem that the water pumping efficiency after self-priming is significantly reduced.

OBJECTS OF THE INVENTION The present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a self-priming centrifugal pump that is small in size and has high pumping efficiency.

Structure of the Invention In order to achieve the above object, the present invention includes a volute chamber and a steam/water separation chamber located above the volute chamber and communicated with the volute chamber, and the steam/water separation chamber has a discharge port and a return water. A self-priming centrifugal pump is constructed in which a passageway is provided, and a rectifying wall hanging from an earthen wall is provided in the return water passage. During self-priming operation, the rectifying wall plays the role of separating air and water, and during normal pumping operation, the rectifying wall acts as resistance in the return water passage, making it possible to create a self-priming centrifugal pump with high pumping efficiency. It is possible.

DESCRIPTION OF EMBODIMENTS FIG. 4 shows a return water passage section of a self-priming centrifugal pump according to an embodiment of the present invention, which is characterized by a rectifying wall hanging down from the upper wall 13 of a part of the return water passage 7. The configuration includes 14. Note that the other configurations are the same as those shown in FIGS. 1 to 3 above.

According to this configuration, the flow of air bubbles is blocked by the rectifying wall 14 provided so as to hang down from the upper wall 13 of a part of the return water passage 7, and the return water from which air bubbles have been removed is passed through the lower part of the rectifying wall 14. , can be led to the circulation hole 8. During self-priming, since the water inside the impeller 4 is a mixture of air and water, the pumping capacity is also reduced. It is convenient to cut off the flow at 14. Furthermore, if the air bubbles stopped by the rectifying wall 14 accumulate, the buoyancy will become stronger.
The water is discharged from the discharge port in the direction of the arrow 16 against the flow of the return water, and there is no problem with the self-priming action. Further, when transitioning to normal water pumping operation, the rectifying wall 14 acts as a resistance to the return water passage 7, which is advantageous even during normal water pumping operation that does not require return water.

Effects of the Invention As described above, according to the present invention, the rectifying wall provided hanging from the earthen wall of the return water passage can prevent the self-priming efficiency from decreasing when the air-water separation chamber is downsized. Therefore, the air-water separation chamber is made smaller, and there is no reduction in pumping efficiency that would otherwise occur due to a large air-water separation chamber, making it possible to provide a pump with high pumping efficiency.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional self-priming centrifugal pump, Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1, Fig. 3 is a cross-sectional view taken along line B-B in Fig. 1, and Fig. 4 is a cross-sectional view taken along line A-A in Fig. 1. FIG. 2 is a sectional view of a return water passage of a self-priming centrifugal pump according to an embodiment of the present invention. 1... Pump case, 2... Casing, 3... Casing cover, 4...
Impeller, 6... Volute chamber, 7...
Return water passage, 8... Circulation hole, 9... Air-water separation chamber, 14... Rectification wall.

Claims (1)

[Claims] A volute chamber and a steam/water separation chamber located above the volute chamber and communicating with the volute chamber, the steam/water separation chamber having a discharge port and a return water passage through which the return water flows to a circulation hole, A self-priming centrifugal pump with a rectifying wall hanging from the earthen wall of the water passage.