CN108603507B

CN108603507B - Suction housing for multi-stage submersible pump, and multi-stage submersible pump

Info

Publication number: CN108603507B
Application number: CN201780010440.7A
Authority: CN
Inventors: 平本和也; 前田毅
Original assignee: Co-Op Yuanyuan Manufacturing Workshop
Current assignee: Co-Op Yuanyuan Manufacturing Workshop
Priority date: 2016-02-10
Filing date: 2017-02-06
Publication date: 2020-02-07
Anticipated expiration: 2037-02-06
Also published as: JP2017141735A; BR112018016288A2; TWI710704B; JP6624962B2; TW201730436A; BR112018016288B1; CN108603507A; WO2017138472A1

Abstract

The invention provides a suction shell for a multi-stage submersible pump and the multi-stage submersible pump. In a multi-stage submersible pump, inflow water to the pump can be pre-rotated without adding a special component. A suction housing for a multistage submersible pump for treating a liquid includes a plurality of housing main bodies extending along an axis and arranged at intervals in a circumferential direction around the axis. A plurality of suction ports are formed along the circumferential direction by gaps between the plurality of casing bodies. The plurality of suction ports are formed such that, in a cross section orthogonal to the axis, the inflow direction of the liquid to each of the plurality of suction ports is in a direction different from the direction toward the axis, and the inflow direction of the liquid to each of the plurality of suction ports is formed such that the inflow direction of the liquid to one of the plurality of suction ports is in a direction rotated by a predetermined angle about the axis.

Description

Suction housing for multi-stage submersible pump, and multi-stage submersible pump

Technical Field

The present invention relates to a suction housing for a multi-stage submersible pump.

Background

Multi-stage submersible pumps for treating liquids are known (e.g. for deep wells). Such a multistage submersible pump is configured by coupling a plurality of casings each containing an impeller therein in the axial direction. For example, patent document 1 described below discloses a liquid crystal display device including: the submersible pump includes a suction casing fixed to the underwater motor, a plurality of intermediate casings having guide vanes and stacked in a multi-stage manner on the upper portion of the suction casing, and a discharge casing attached to the uppermost intermediate casing. In the multistage submersible pump, water sucked from the suction casing flows linearly in the axial direction into the intermediate casing.

Patent document 1: japanese laid-open patent publication No. 6-323291

Patent document 2: japanese patent laid-open publication No. 2005-320869

Patent document 3: japanese Kokai Utility model Showa 54-24103

In the multi-stage submersible pump as described above, it is generally a problem how to suppress the loss and improve the pump efficiency. In order to suppress the loss, it is desirable that the water flowing into the impeller flows linearly in the axial direction (the direction in which the pump shaft extends). On the other hand, one of the causes of the loss is the peeling of water inside the intermediate casing having the guide vanes. In order to suppress the peeling, it is preferable to avoid an extreme change in the water flow direction. In the multistage submersible pump, water to which a rotational component is applied by the impeller of the 1 st stage flows into the intermediate casing after the 2 nd stage. In order to approach the ideal state, the inflow water having the rotational component is changed to a linear flow, but this causes an extreme change in the flow direction of the water, and as a result, peeling is likely to occur. That is, there is a trade-off relationship between suppressing the loss by setting the flow of water flowing into the impeller to a linear flow in the axial direction and suppressing the loss by avoiding an extreme change in the flow direction of water.

In the multi-stage submersible pump in which the flow direction of the water flowing into the intermediate casing of the 1 st stage is linear and the flow of the water flowing into the 2 nd and subsequent stages has a rotational component, in recent years, the impeller of the multi-stage submersible pump may be designed so that the impeller can exhibit the highest performance in the inflow flow having a predetermined rotational component, considering that the flow of the water having the rotational component dominates the entire multi-stage submersible pump. Such a designed impeller is also referred to as a rotary designed impeller. In a multistage submersible pump provided with a rotationally designed impeller, a certain degree of good efficiency can be ensured as the entire pump.

However, in the rotary design impeller, the flow direction of the water flowing into the 1 st stage is a linear flow different from the optimum design condition, and therefore the performance of the impeller of the 1 st stage is inferior to that of the impellers of the 2 nd and subsequent stages. Therefore, the multistage submersible pump including the rotary design impeller has room for improvement in efficiency.

As one of the methods for improving the efficiency of the multistage submersible pump including the rotationally designed impeller, it is considered to design the impeller of the 1 st stage separately from the impellers of the 2 nd and subsequent stages so as to be able to exhibit the highest performance with respect to the linear water flow having no rotational component. However, in this case, the same impeller shape cannot be used for each stage, and the number of types of parts increases. As a result, the number of manufacturing steps increases, the cost increases, and the maintenance manageability decreases.

As another method of improving the efficiency of a multistage submersible pump having a rotary design impeller, it is considered to improve a suction casing so that the water flowing into the 1 st stage contains a rotational component in the water flow direction. As a technique for imparting a rotating component to inflow water of a pump, for example, patent documents 2 and 3 are known. In patent documents 2 and 3, an arc-shaped flow regulating plate (water guide plate) is provided in the suction flow path, and thereby a rotational component (also referred to as prerotation) is given to the inflow water. However, the addition of such a rectifying plate leads to complication of the apparatus, high cost, complication of maintenance, and the like.

In view of the above, a technology is desired for a multistage submersible pump that can pre-rotate inflow water to the pump without adding any special component.

Disclosure of Invention

The present invention has been made to solve at least part of the above problems, and can be realized, for example, as the following aspects.

According to a first aspect of the present invention, there is provided a suction casing for a multistage submersible pump for treating a liquid. The suction housing includes a plurality of housing main bodies extending along an axis and arranged at intervals in a circumferential direction around the axis. A plurality of suction ports are formed in the circumferential direction by gaps between the plurality of casing bodies. The plurality of suction ports are formed such that, in a cross section orthogonal to the axis, the inflow direction of the liquid to each of the plurality of suction ports is in a direction different from the direction toward the axis, and the inflow direction of the liquid to each of the plurality of suction ports is formed such that the inflow direction of the liquid to one of the plurality of suction ports is in a direction rotated by a predetermined angle about the axis.

According to the suction housing, the liquid flowing from the plurality of suction ports can form a swirling flow. That is, the liquid flowing into the 1 st stage of the multistage submersible pump can be pre-rotated. Further, it is not necessary to add a member such as a rectifying plate.

According to a second aspect of the present invention, there is provided a suction casing for a multistage submersible pump for treating a liquid. The suction housing includes a plurality of housing main bodies extending along an axis and arranged at intervals in a circumferential direction around the axis. A plurality of suction ports are formed along the circumferential direction by gaps between the plurality of casing bodies. The plurality of suction ports are formed such that the liquid flowing in from the plurality of suction ports flows in a direction different from a direction toward the axis in a cross section orthogonal to the axis, and generates a swirling flow. According to the suction housing, the same effects as those of the first embodiment are achieved.

According to a third aspect of the present invention, in the first or second aspect, the plurality of suction ports are formed such that the inflow direction of the liquid to each of the plurality of suction ports is rotationally symmetrical about the axis. According to the above aspect, more uniform pre-rotation can be generated.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the suction housing further includes a flange portion that connects the plurality of housing main bodies to each other in a circumferential direction at one end or both ends in an axial direction of the plurality of housing main bodies. According to the above aspect, the suction casing, the intermediate casing, and the motor can be easily coupled by the flange portion, and therefore, the assembly of the multistage submersible pump is facilitated.

According to a fifth aspect of the present invention, there is provided a multistage submersible pump for treating a liquid. The multistage submersible pump includes a suction housing in any one of first to fourth modes; a motor disposed on one side of the suction casing in the axial direction; and an intermediate casing which is arranged in a plurality of stages on the other side of the suction casing and accommodates an impeller rotationally driven by the motor in each stage. According to the multistage submersible pump, the same effects as those of any of the first to fourth embodiments are achieved.

Drawings

Fig. 1 is a sectional view showing a schematic structure of a multistage submersible pump according to an embodiment of the present invention.

Fig. 2 is a perspective view of the suction housing.

Fig. 3 is a sectional view of the suction housing taken along line a-a of fig. 1.

Fig. 4 is a cross-sectional view of a suction housing as a comparative example corresponding to fig. 3.

Detailed Description

A. Example (b):

fig. 1 is a sectional view showing a schematic structure of a multistage submersible pump 20 according to an embodiment of the present invention. The multistage submersible pump 20 (hereinafter, also simply referred to as the pump 20) is, in the present embodiment, a deep well submersible pump provided so that the whole is submerged in well water. However, the purpose of the pump 20 is not limited and the pump 20 may be any multi-stage submersible pump that handles liquids. The number of stages can be any number of 2 or more.

As shown in the drawing, the pump 20 includes a motor 30, a shaft 40, a suction casing 100, and

intermediate casings

50, 60, and 70 connected in multiple stages. The shaft 40 extends lengthwise inside the pump 20 and has an axis AL. The shaft 40 is coupled to the motor 30 via a coupling 41.

The suction housing 100 is configured to be coaxial with the axis AL. The suction casing 100 includes a suction casing main body 110 and

flange portions

120 and 130. The suction casing 100 has a suction port 111 (in the present embodiment, 4 suction ports 111a to 111d are formed as described later, but these are collectively referred to as the suction port 111). The suction casing 100 is fixed to the motor 30 by a bolt 125 at one end side in the axis AL direction and fixed to the intermediate casing 50 by a bolt 135 at the other end side.

The

intermediate cases

50, 60, 70 are connected in this order along the axis AL in a plurality of stages as viewed from the motor 30 side.

Impellers

51, 61, 71 are housed in the

intermediate casings

50, 60, 70, respectively. The

impellers

51, 61, 71 are fixed around the shaft 40.

Guide vanes

52, 62, and 72 are provided inside the

intermediate casings

50, 60, and 70 so as to be connected to the

impellers

51, 61, and 71, respectively.

In the pump 20, when the motor 30 is driven, the shaft 40 rotates together with the

impellers

51, 61, and 71. Accordingly, water flows into the suction housing 100 from the suction port 111 as indicated by an arrow a1, and flows toward the intermediate housing 50 along the axis AL. The water flowing into the intermediate casing 50 of the 1 st stage is sent to the guide vanes 52 by the impeller 51, is pressurized by the guide vanes 52, and flows into the intermediate casing 60 of the 2 nd stage. Similarly, the water flowing into the intermediate casing 60 of the 2 nd stage is sent to the guide vanes 62 by the impeller 61, is pressurized by the guide vanes 62, and flows into the intermediate casing 70 of the 3 rd stage. In this way, the water flowing in from the suction port 111 is sequentially pressurized in each stage, sent to the subsequent stage, and discharged from the discharge casing (not shown) connected to the subsequent stage of the last intermediate casing (not shown).

Fig. 2 is a perspective view of the suction housing 100. Figure 3 is a cross-sectional view of the suction housing 100 taken along line a-a of figure 1 orthogonal to axis AL. As shown in fig. 3, the suction casing 100 in this embodiment includes 4 suction casing main bodies 110a to 110 d. As shown in fig. 2, the suction housing main bodies 110a to 110d extend along an axis AL. As shown in fig. 3, the suction casing main bodies 110a to 110d are arranged at intervals in the circumferential direction around the axis AL. In the present embodiment, the suction casing main bodies 110a to 110d have the same shape and have an L-shaped cross section. However, the shapes of the suction casing main bodies 110a to 110d can be set arbitrarily. In the present embodiment, the suction casing main bodies 110a to 110d are arranged so as to be rotationally symmetrical about the axis AL.

As shown in fig. 3, 4 suction ports 111a to 111d are formed along the circumferential direction by the gaps between the adjacent suction casing main bodies among the suction casing main bodies 110a to 110 d. In the present embodiment, since the suction housing main bodies 110a to 110d having the same shape are arranged to be rotationally symmetrical about the axis AL, the suction ports 111a to 111d are also arranged to be rotationally symmetrical about the axis AL.

As shown in fig. 3, the suction ports 111a to 111d are formed such that the inflow directions a2 to a5 of water in the suction ports 111a to 111d are different from the directions toward the axis AL. Since the suction ports 111a to 111d are arranged to be rotationally symmetric about the axis AL, the inflow directions a2 to a5 of water are also rotationally symmetric about the axis AL (in the present embodiment, 90-degree rotational symmetry).

As shown in fig. 3, the rotational flow indicated by arrow a6 can be generated by the water flowing from the suction ports 111a to 111d according to the inflow directions a2 to a5 of the suction ports 111a to 111 d. That is, the water flowing in from the suction ports 111a to 111d flows along the axis AL while rotating around the axis AL, and flows into the intermediate casing 50 of the 1 st stage. Therefore, the water flowing into the intermediate casing 50 of the 1 st stage can be pre-rotated without adding a rectifying plate or the like. As a result, the flow of the inflowing water can be made into a swirling flow in all the stages including the 1 st stage. Therefore, the efficiency of the multistage submersible pump including the rotationally designed impeller can be improved. In the present embodiment, the inflow directions a2 to a5 of the suction ports 111a to 111d are formed to be rotationally symmetric about the axis AL, and therefore, more uniform pre-rotation can be generated.

The inflow directions a2 to a5 may be arbitrarily set so that the inflow direction of water at one of the suction ports 111a to 111d is rotated by a predetermined angle about the axis AL. That is, the inflow direction of each suction port can be arbitrarily set so that the flow direction of the water flowing from the suction port does not become a direction for canceling the swirling flow. The number of the suction ports is not limited to 4, and may be any number of 2 or more. In other words, the number of the suction casing main bodies can be set to any number of 3 or more. The inner surface of the suction casing main body (the inner surface forming the flow path) may have any shape, and may be formed into an arc shape (e.g., a shape of a part of a circle centered on the axis AL) in order to suppress a rapid change in the flow direction of water as much as possible.

As shown in fig. 2, the suction casing 100 includes

flange portions

120 and 130. The

flange portions

120 and 130 are formed at both ends of the suction casing main bodies 110a to 110d in the axis AL direction, and connect the suction casing main bodies 110a to 110d in the circumferential direction. The flange portion 120 is formed at the end of the suction casing main bodies 110a to 110d on the motor 30 side. A plurality of bolt holes 121 are formed in the flange portion 120 in the circumferential direction. As described above, the motor 30 and the suction housing 100 can be fixed to each other by the bolt 125 through the bolt hole 121.

The flange portion 130 is formed at the end of the suction housing main bodies 110a to 110d on the side of the intermediate housing 50. The flange portion 130 includes a first large diameter portion 131 adjacent to the suction casing main bodies 110a to 110d, a second large diameter portion 133 adjacent to the intermediate casing 50, and a small diameter portion 132 between the first large diameter portion 131 and the second large diameter portion 133. A plurality of bolt holes 134 are formed in the second large diameter portion 133 in the circumferential direction. The bolt hole 134 is formed radially outward of the outer peripheral surface of the small diameter portion 132. As described above, the suction casing 100 and the intermediate casing 50 can be fixed to each other by the bolt 135 using the bolt hole 134. Further, since the small diameter portion 132 is formed, the insertion and movable region of the bolt tightening tool are satisfactorily secured, and therefore, the bolt 135 can be easily tightened even at the formation position of the suction housing main bodies 110a to 110d on the plane orthogonal to the axis AL.

As shown in fig. 3,

notches

122 and 123 are formed in the flange 120. The

notches

122 and 123 can be used as a space for accommodating a power cable connected to the motor 30.

Fig. 4 is a cross-sectional view of a suction housing 200 as a comparative example, corresponding to fig. 3. As shown in the drawing, the suction casing 200 includes 4 suction casing main bodies 210a to 210d having a substantially U-shape, and suction ports 211a to 211d are formed by gaps therebetween. The inflow directions a7 to a10 of water at the suction ports 211a to 211d are directed toward the axis AL. In the suction housing 200, the swirling flow indicated by the arrow a6 in fig. 3 does not occur, and the water flowing in from the suction ports 211a to 211d is directed linearly toward the intermediate housing 50 along the axis AL. Therefore, when the suction housing 200 is used in the multistage submersible pump including the rotary design impeller, the efficiency of the stage 1 is lower than that in the case of using the suction housing 100 of the present embodiment.

Although the embodiments of the present invention have been described above, the embodiments of the present invention are not intended to limit the present invention, but are for easy understanding of the present invention. The present invention can be modified and improved without departing from the gist thereof, and it goes without saying that the present invention includes equivalents thereof. In addition, the respective components described in the technical means and the description may be combined or omitted within a range in which at least a part of the above-described problems can be solved or within a range in which at least a part of the effects can be achieved.

Description of reference numerals

20 … multi-section submersible pump

30 … motor

40 … axle

41 … shaft coupling

50. 60, 70 … middle shell

51. 61, 71 … impeller

52. 62, 72 … guide vane

100 … suction casing

110. 110a, 110b, 110c, 110d … are drawn into the housing body

111. 111a, 111b, 111c, 111d … inlet

120. 130 … flange portion

121. 134 … bolt hole

122. 123 … incision

125. 135 … bolt

131 … first large diameter part

132 … minor diameter portion

133 … second major diameter

AL … axis

Claims

1. A suction housing for a multistage submersible pump for treating liquids, wherein,

the device comprises a plurality of shell bodies extending along an axis and arranged at intervals in the circumferential direction with the axis as the center,

a plurality of suction ports are formed along the circumferential direction by utilizing the gaps between the plurality of casing bodies,

the plurality of suction ports are provided, in a cross section orthogonal to the axis,

the inflow direction of the liquid to each of the plurality of suction ports is in a direction different from the direction toward the axis,

the liquid inflow direction of each of the plurality of suction ports is formed such that the liquid inflow direction of one of the plurality of suction ports is rotated by a predetermined angle about the axis with respect to the liquid inflow direction of the other suction port adjacent to the one suction port.

2. A suction housing for a multistage submersible pump for treating liquids, wherein,

the plurality of suction ports are formed such that the liquid flowing in from the plurality of suction ports flows in a direction different from a direction toward the axis in a cross section orthogonal to the axis, and generates a swirling flow.

3. An inhalation housing according to claim 1 or 2, wherein,

the plurality of suction ports are formed such that the inflow direction of the liquid to each of the plurality of suction ports is rotationally symmetrical about the axis.

4. An inhalation housing according to claim 1 or 2, wherein,

the housing further includes a flange portion that connects the plurality of housing main bodies to each other in the circumferential direction at one end or both ends of the plurality of housing main bodies in the axial direction.

5. The suction housing of claim 3,

6. A multistage submersible pump for processing liquid, comprising:

an inhalation housing according to any one of claims 1 to 5;

a motor disposed on one side of the suction housing in the axial direction; and

and an intermediate casing which is arranged in a plurality of stages on the other side of the suction casing and accommodates an impeller rotated and driven by the motor in each stage.