JPH0925896A - Downsized shape of pump delivery volute casing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the width required for the installation of a pump and to downsize a casing by arranging one delivery passage from one tongue end and the other delivery passage from the other tongue end in a state of being overlapped in a parallel direction to the axis of the pump. SOLUTION: A first delivery passage 1 from a tongue end A1, and a second discharge passage 2 from a tongue end B1 are overlapped in a parallel direction to the axis (a) of a pump and disposed with a small offset quantity so that the passage 1 is placed on top of the passage 2. In comparison to the conventional parallel layout in an orthogonal direction to the pump axis, the whole delivery passage width W, that is, the width W4 required for the installation of the pump, is reduced by the width approximately equal to the width of one passage, and civil engineering works cost for installation can be reduced. The first delivery passage 1 can be also divided and arranged in a plurality of stages. The width of an outlet in two-stage layout is thereby reduced by the overlap width of the passages 1, 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compact shape of a pump discharge volute casing.

[0002]

2. Description of the Related Art In recent years, pump stations, which are planned as urban flood countermeasures, tend to have a large capacity and a high head year by year, and in order to reduce the cost increase accompanying the enlargement of the stations, the pumps should be made compact. It is important to. Therefore, it is desired to reduce the installation width of the pump by making the pump compact and to reduce the cost in terms of civil engineering costs.

In order to make the pump compact, it is necessary to reduce the cross-sectional area of the suction passage, that is, to speed up the flow. However, although there is a concern that vortices will be generated as the flow speed increases, the applicant of the present invention has proposed a technique for preventing the generation of vortices in Japanese Patent Application No. 6-231005, which aims to increase the suction flow velocity, that is, the suction passage. Made possible to be compact.

Therefore, even if the suction passage can be made compact, if the entire width of the discharge passage is not reduced, the required pump installation width for the pump installation becomes large, and the civil engineering cost and other costs are reduced. Since it is the same as the conventional one, it is desired to reduce the width of the discharge flow channel.

A conventional discharge double volute casing 1
0, as shown in FIGS. 4 and 5, the winding start tongue positions, that is, the tongue ends A1 and B1 are set to 45 ° and 22 ° from the cross section I perpendicular to the flow direction F indicated by the arrow.
The first discharge flow path 11 from the tongue end A1 is positioned near 5 °.
In order to direct the flow in the volute nozzle direction, that is, in the discharge port direction, while ensuring each cross-sectional area between the tongue end B1 and the second discharge flow path 12, the flow paths 11 and 12 are orthogonal to the axis a of the pump. It was necessary to arrange them in parallel so that the discharge passage overall width W1 was large.

Further, the total width W1 of the discharge flow path is equal to the total width W of the suction flow path.
Therefore, the required pump installation width W2 was also increased.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a compact pump discharge volute casing shape which reduces the required pump installation width.

[0008]

According to the present invention, in a discharge double volute casing, one discharge flow passage from one tongue end and the other discharge flow passage from the other tongue end are connected to the pump axis. They are arranged in a parallel direction.

In the compact form of the pump discharge volute casing constructed as described above, both discharge flow passages from both tongue ends are arranged in a direction parallel to the pump axis, so that the conventional discharge discharge volute casing is formed. As compared with the pumps arranged in parallel in the direction orthogonal to the pump axis, the entire width of the discharge passage, that is, the required pump installation width is reduced by a width substantially equal to the width of one of the passages.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

1 and 2, the first discharge flow passage 1 from the tongue end A1 and the second discharge flow passage 2 from the tongue end B1 at the same position as in FIG. 4 are in the direction parallel to the axis a of the pump. At
They are arranged so as to overlap with each other, that is, in the illustrated example, the flow path 1 is on the upper side and with a small offset amount b. The first discharge channels 1 and 11 and the second discharge channels 2 and 12 are formed to have the same channel cross-sectional area.

FIG. 3 shows an example in which the first discharge passage 1 is further divided into upper and lower parts. In the example of FIG. 2, they are arranged in two stages, but in FIG. 3, they are arranged in three stages.

Next, the operation will be described. The width w1 of the outlet portion in FIG. 2 is significantly reduced by the overlapping width of the flow paths 1 and 2 with respect to the width w2 shown in FIG.

For this reason, the total width W3 of the discharge passage is significantly reduced as compared with the total width W1 of the discharge passage shown in FIG. Therefore, it becomes smaller than the entire width W of the suction passage. As a result, the required pump installation width W4 becomes the same as the suction passage overall width W, which is significantly reduced compared to the conventional case.

[0015]

EFFECTS OF THE INVENTION Since the present invention is configured as described above, it is possible to reduce the entire discharge flow passage width, that is, the required pump installation width, and to reduce installation civil engineering costs.

[Brief description of drawings]

FIG. 1 is a top view showing one embodiment of the present invention.

FIG. 2 is a view as viewed in the direction of the arrow X in FIG. 1;

FIG. 3 is a diagram showing an example in which a first discharge flow path is further divided into upper and lower parts and arranged in three stages.

FIG. 4 is a top view showing a conventional shape.

5 is a view on arrow X in FIG.

[Explanation of symbols]

 A1, B1 ... Tongue end a ... Pump axis F ... Flow direction W ... Suction passage full width W1, W3 ... Discharge passage full width W2, W4 ... Pump installation required width w1 , W2 ... Width of outlet part θ ... Tongue angle 10 ... Discharge double volute casing 1, 11 ... First discharge flow path 2, 12 ... Second discharge flow path

Claims (1)

[Claims] 1. In a discharge double volute casing, one discharge flow path from one tongue end and the other discharge flow path from the other tongue end are arranged in a direction parallel to the pump axis. The compact shape of the pump discharge volute casing, which is characterized by this.