JPH05306696A - Aeration structure of pump - Google Patents

Abstract

PURPOSE:To effectively restrain oscillation of a pump generated at the time of pumping cutoff or low output drive execution. CONSTITUTION:A hollow opposed member 11 with a hollow part 11A of a roughly cut head conical section opposing to an impeller boss 8A of a pump P is arranged, and an air supply passage 13 directing an air supply outlet 13A in the tangential direction of the hollow part 11A is provided so as to swirl the air or the air mixed water in the hollow part 11A. The air discharged from the air supply outlet l3A is split into small bubbles 17, 17... from an outlet 11 of the hollow opposed member 11 and flown in between blades 8B, 8B... of an impeller 8 while the small bubbles 17, 17... are dispersed uniformly in petals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aeration structure of a pump suitable for a preceding standby operation, a low output operation, etc., which is installed in an intake well of a drainage pump station installed in a water channel or rainwater pump equipment.

[0002]

2. Description of the Related Art Conventionally, a casing 2 of a vertical pump P installed in an intake well 1 of a drainage pump station shown in FIG. 5 is connected to an intake pipe 3 open to the atmosphere, and a water level gauge 4 is connected to the intake pipe 3. An intake valve 5 that is controlled to open and close based on a water level detection signal from the engine is provided. When the intake valve 5 is opened, air is sent to the casing 2 to shut off pumped water (drainage) and perform a preceding standby operation. The aeration structure of such a pump is known. However, in this type of conventional pump air mixing structure, the intake pipe 3
3a is set on the inner surface of the casing 2 away from the axis C of the main shaft 7 and the impeller 8, so that the opening of the intake valve 5 causes large air bubbles to be unevenly introduced into the impeller 8. Then, due to the uneven flow of the large bubbles, the vertical pump P
It has a drawback that vibration is generated.

[0003]

A problem to be solved is that air is unevenly introduced into the impeller of the pump, which causes vibration.

[0004]

The invention according to claim 1 is a case
The distal end surface of the impeller boss rotating with the main shaft in the shing and the distal end surface of the hollow facing member are arranged to face each other with a gap, and the outlet is open to the distal end surface of the hollow facing member, An air supply passage having an air supply outlet opening in a direction in which a swirl flow is generated in the hollow portion of the hollow facing member is provided, and pump vibration during pumping interruption or low output operation is effective. Achieved the purpose of suppressing.

According to a second aspect of the present invention, the tip end surface of the impeller boss rotating with the main shaft in the casing and the tip end surface of the hollow facing member are arranged to face each other with a gap, and the outlet is of the hollow shape. A swirl vane is opened in the front end surface of the facing member, a swirl vane is rotatably inserted in the hollow part of the hollow facing member, and an air supply passage having an air supply outlet is provided in the hollow part. The pump vibration is effectively suppressed when pumping is cut off or low-power operation is executed.

[0006]

According to the present invention, when air or aerated water is discharged from the air supply outlet of the air supply passage into the hollow portion of the hollow facing member in the swirling flow generating direction, the discharged air or The air in the aerated water swirls in the hollow part, has a large tangential velocity, splits into small bubbles from the outlet of the hollow opposing member, and flows into the impeller while being dispersed evenly in a petal shape, which causes Execute pumping cutoff or low power operation.

According to the second aspect of the present invention, the air discharged from the air supply outlet of the air supply passage into the hollow portion of the hollow opposed member or the air in the aerated water is given a rotational force by the swirl vanes to be hollow. It swirls in the section, has a high tangential velocity, splits into small bubbles from the outlet of the hollow opposed member, flows into the impeller while being evenly dispersed in a petal shape, and shuts off pumping or performs low-power operation of the pump. ..

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic vertical sectional view of a vertical shaft mixed flow pump to which the first invention is applied. In the figure, a vertical mixed-flow pump P includes a main shaft 7, an impeller 8 fixed to the main shaft 7, a casing 2 in which the impeller 8 is rotatably mounted, and a casing.
A discharge pipe 9 and a suction bell mouth 10 which are connected to communicate with the upper and lower sides of the single 2 are provided. The upper end of the main shaft 7 is connected to a prime mover (not shown), and the main shaft 7 and the impeller 8 are rotated by the prime mover. The impeller 8 is composed of an impeller boss 8A and a plurality of blades 8B, 8B which are integrally attached to the impeller boss 8A. The impeller boss 8A is provided with a main shaft 7 via a key (not shown). It is mounted so that it can rotate at the same time. Further, a hollow facing member 11 is arranged so as to face the lower side of the impeller boss 8A. The hollow facing member 11 is made of concrete erected at the bottom of the water intake well 1, and as shown in FIG. 2, has a hollow portion 11A having a substantially frustoconical cross section, and its upper end surface 11B is horizontal. Is formed flat in the direction, the outlet 11C is opened in the upper end surface 11B, and the upper end surface 11B and the lower end surface 8a of the impeller boss 8A formed flat in the horizontal direction face each other with a gap 12 therebetween. There is. On the other hand, on the bottom side of the hollow portion 11A, the air supply passage 1 in which the air supply outlet 13A is tangentially oriented.
3 is provided, and the inlet of the air supply passage 13 is connected to the air supply means 14 of FIG. On the other hand, a valve body 5 formed of an electromagnetic valve or an electric valve is provided in the air supply passage 13, and the valve body 5
Is controlled to be opened and closed by a control signal output from the controller 16 based on the water level signal detected by the water level gauge 15, for example.

In the above configuration, it is assumed that the water level of the suction well 1 is lowered to, for example, the pumping cutoff water level by continuing the pumping operation (draining operation) by rotating the impeller 8. This water level is detected by the water level gauge 15, and the water level detection signal is sent to the controller 16
Entered in. As a result, a valve opening signal is output from the controller 16 to the valve body 5 to fully open the valve body 5. Therefore, air is sent from the air supply means 14 to the air supply passage 13, and the sent air is tangentially discharged from the air supply outlet 13A of the air supply passage 13 to the hollow portion 11A of the hollow facing member 11. The air discharged in the tangential direction is the outlet 1 of the hollow portion 11A.
As it goes to 1C, it is squeezed on the inner surface of the hollow portion 11A and reaches a large tangential velocity. Therefore, from the outlet 11C of the hollow facing member 11, small bubbles 17, 17
Impeller 8 while splitting into ... and evenly distributed like petals
Between the blades 8B, 8B ... of the pump, and the pump P is cut off to start the preceding standby operation. In this way, the small bubbles 17, 17 ...
Since the flow is made to flow between B, 8B, ..., It is possible to effectively suppress the vibration of the pump P that has conventionally been generated at the time of inflow of air.

FIG. 3 is a longitudinal sectional view showing a main part of a vertical mixed flow pump to which the second invention is applied. The same or corresponding parts as those of the first invention are designated by the same reference numerals, and detailed description thereof will be omitted. In this figure, a swirl vane 18 is attached to an impeller boss 8A so as to be rotatable at the same time, and the swirl vane 18 is pivotally inserted into an intermediate hollow portion 11A through an outlet 11C of a hollow facing member 11, and An air supply passage 13 having an air supply outlet 13A opened upward is provided below the swirl vane 18 inside the hollow portion 11A.

With such a structure, the air supply outlet 13A of the air supply passage 13 to the hollow portion 11A of the hollow facing member 11 are connected.
The air discharged to the air is given a rotational force by the swirl vane 18 and is squeezed in the hollow portion 11A while being squeezed by the inner surface of the hollow portion 11A toward the outlet 11C, and has a large tangential velocity. That is, the air discharged into the hollow portion 11A is provided with the rotational force by the swirl vane 18 and the hollow portion 11A.
The synergistic effect of the throttling action by the inner surface of A leads to possessing a large tangential velocity. Therefore, the outlet 11C of the hollow facing member 11, more specifically, the inner circumference of the outlet 11C and the outer circumference of the blade axis of the swirl vane 18 are divided into small bubbles 17, 17 ... While flowing into the blades 8B, 8B of the impeller 8 ... Between the blades 8B, 8B. In this way, small air bubbles 17, which are evenly dispersed in a petal shape,
.. is made to flow between the blades 8B, 8B of the impeller 8. Therefore, it is possible to effectively suppress the vibration of the pump P that has conventionally been generated when the air was introduced. Note that, as shown in FIG. 4, the swirl vane 18 may be separated from the impeller boss 8A and driven by another prime mover 19.

In each of the above embodiments, the valve body 5 is fully opened,
Although the operation of sending a large amount of air from the outlet 13A of the air supply passage 13 to interrupt the pumping has been described, by adjusting the opening degree of the valve body 5 to reduce the amount of sending of the air, a low output that limits the pumping amount to a small amount. The operation can be performed while suppressing vibration. Also, by changing to air and discharging the aerated water from the outlet 13A of the air supply passage 13,
Vibration can be suppressed and low output operation can be performed. Furthermore, it goes without saying that the present invention can be applied not only to the vertical shaft mixed flow pump described in the above embodiment but also to other pumps capable of preceding standby operation. In addition, the air supply passage 13 of FIG.
Water supply means (pump) is branched and connected to the inlet side of the pump, and only water is sent from the air supply passage 13, so that it can be used as a whirling generator for a vertical mixed flow pump or other pump capable of preceding standby operation. Can also

[0013]

As described above, according to the invention of claim 1, the air discharged in the swirling flow generating direction into the hollow portion of the hollow facing member is divided into small bubbles from the outlet of the hollow facing member. Then, the air bubbles can be dispersed evenly in a petal shape, and the small air bubbles evenly dispersed in a petal shape can be made to flow into the impeller, so that pump vibration can be effectively suppressed and pumping cutoff or low output operation can be performed. it can.

According to the first aspect of the present invention, the air discharged into the hollow portion of the hollow facing member is rotated by the swirl vanes to be divided into small bubbles from the outlet of the hollow facing member and dispersed evenly in a petal shape. As a result, the small air bubbles that are evenly dispersed in a petal shape can flow into the impeller, so that vibration of the pump can be effectively suppressed and pumping cutoff or low output operation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic vertical cross-sectional view of a vertical mixed flow pump to which the first invention is applied.

FIG. 2 is an enlarged cross-sectional view of a main part.

FIG. 3 is a vertical sectional view showing a main part of a vertical mixed flow pump to which the second invention is applied.

FIG. 4 is a vertical sectional view showing a modified example of the second invention.

FIG. 5 is a partial vertical cross-sectional view of a vertical mixed flow pump to which a conventional structure is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Absorption well 2 Casing 7 Main shaft 8 Impeller 8A Impeller boss 8a Lower end surface of impeller boss (tip surface of impeller boss) 11 Hollow facing member 11A Hollow part upper end surface of facing member (end surface of facing member) ) 11B Upper end surface of facing member (front end surface of facing member) 11CA Outlet 12 Gap 13 Air supply passage 13A Air supply outlet 18 Swirling vane C axis P Vertical shaft mixed flow pump (pump)

Claims (2)

[Claims] 1. A tip end surface of an impeller boss rotating with a main shaft in a casing and a tip end surface of a hollow facing member are arranged to face each other with a gap, and an outlet is a tip end surface of the hollow facing member. The air mixing structure for a pump, wherein an air supply passage is provided, which is opened to the air supply port and has an air supply outlet opened in a direction in which a swirl flow is generated in the hollow portion of the hollow facing member. 2. A tip end surface of an impeller boss that rotates with a main shaft in a casing and a tip end surface of a hollow facing member are arranged to face each other with a gap, and an outlet is a tip end surface of the hollow facing member. And a swirl vane is rotatably inserted into a hollow portion of the hollow facing member, and an air supply passage having an air supply outlet opened is provided in the hollow portion. Aerated structure.