CN108603507A - The sucking shell and multistage immersible pump of multistage immersible pump - Google Patents

Abstract

The present invention provides a kind of the sucking shell and multistage immersible pump of multistage immersible pump.In multistage immersible pump, not adding special component just can make to generate pre-rotation to the inflow water of pump.The sucking shell of the multistage immersible pump for the treatment of liquid have along axis extend and centered on axis in the circumferential interval configuration multiple housing main bodies.Using the mutual gap of multiple housing main bodies, multiple suction inlets are circumferentially formed.For multiple suction inlets, in the section with axis vertical take-off, the inflow direction of multiple suction inlets liquid of each is in the direction different from the direction towards axis, the inflow direction of multiple suction inlets liquid of each is formed as, and the inflow direction of the liquid of in multiple suction inlets suction inlet is made to be in the direction for having rotated predetermined angular centered on axis.

Description

Suction casings for multi-stage submersible pumps, and multi-stage submersible pumps

technical field

This invention relates to suction casings for multi-section submersible pumps.

Background technique

Multi-stage submersible pumps for handling liquids (for example, submersible pumps for deep wells) are known. Such a multi-stage submersible pump is configured by connecting a plurality of housings in which impellers are housed in the axial direction. For example, the following Patent Document 1 discloses a suction housing fixed to an underwater motor, a plurality of intermediate housings having guide vanes stacked in multiple stages on the upper portion of the suction housing, and a discharge housing attached to the uppermost intermediate housing. Multi-section submersible pump. In this multi-stage submersible pump, the water sucked in from the suction casing linearly flows into the intermediate casing along the axial direction.

Patent Document 1: Japanese Patent Application Laid-Open No. 6-323291

Patent Document 2: Japanese Patent Laid-Open No. 2005-320869

Patent Document 3: Japanese Utility Model Publication No. Showa 54-24103

In the above-mentioned multi-stage submersible pump, generally, how to suppress loss and improve pump efficiency is an issue. In order to suppress loss, it is desirable that the water flowing into the impeller flows linearly in the axial direction (the direction in which the shaft of the pump extends). On the other hand, one of the causes of losses is the stripping of water in the intermediate housing with guide vanes. In order to suppress this peeling, it is preferable to avoid extreme changes in the water flow direction of the water. In the multi-stage submersible pump, the water to which the rotation component is given by the impeller of the first stage flows into the intermediate housing of the second stage and later. In order to approach the above ideal state, the inflow water having this swirling component is changed into a straight water flow, but this brings about an extreme change in the flow direction of the water, and as a result, peeling tends to occur. That is, there is a trade-off relationship between suppressing losses by making the flow of water flowing into the impeller a linear flow in the axial direction, and suppressing losses by avoiding extreme changes in the flow direction of water.

In this way, in the multi-stage submersible pump in which the flow direction of the water flowing into the intermediate casing of the first stage is a straight line but the flow of water flowing into the second stage and later has a rotating component, in recent years, considering the multi-stage submersible pump as a whole, While the flow of water having a rotational component dominates, the impeller of a multistage submersible pump may be designed so that the impeller can exhibit the highest performance in an inflow water flow having a predetermined rotational component. Such designed impellers are also referred to as rotary design impellers. In a multi-stage submersible pump with a rotating design impeller, a certain degree of good efficiency can be secured as a whole of the pump.

However, in the rotary design impeller, the flow direction of the water flowing into the first stage is a straight flow different from the design optimum condition, so the performance of the first stage impeller is inferior to that of the second and subsequent impellers. Therefore, there is room for improvement in the efficiency of multi-section submersible pumps with impellers of rotating design.

As one of the methods to improve the efficiency of multi-stage submersible pumps with rotating design impellers, it is considered to design the first-stage impeller separately from the second-stage and subsequent impellers, so as to be able to exert the highest performance for linear water flow without rotating components . However, in this case, impellers of the same shape cannot be used in each stage, and the types of components increase. As a result, an increase in manufacturing man-hours, an increase in cost, a decrease in maintenance and management properties, and the like are caused.

As another method of improving the efficiency of a multi-stage submersible pump with a rotating design impeller, it is conceivable to modify the suction casing so that the flow direction of the water flowing into the first stage includes a rotating component. As a technique for imparting a swirl component to inflow water of a pump, for example, the aforementioned Patent Documents 2 and 3 are known. In Patent Documents 2 and 3, a swirl component (also referred to as pre-swirl) is given to inflow water by providing an arcuate straightening plate (water guide plate) in the suction flow path. However, adding such a rectifying plate leads to complexity of the device, high cost, and maintenance complexity.

Based on the above circumstances, there has been demanded a technique for pre-rotating the inflow water to the pump in the multi-stage submersible pump without adding special components.

Contents of the invention

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

According to a first aspect of the present invention, there is provided a suction casing for a multi-stage submersible pump handling liquid. The suction housing includes a plurality of housing main bodies extending along the axis and arranged at intervals in the circumferential direction centering on the axis. A plurality of suction ports are formed in the circumferential direction by utilizing gaps between the plurality of casing main bodies. For a plurality of suction ports, in a section perpendicular to the axis, the liquid inflow direction of each of the plurality of suction ports is in a direction different from the direction toward the axis, and the liquid inflow direction of each of the plurality of suction ports forms a To make the inflow direction of the liquid in one of the plurality of suction ports rotated by a predetermined angle around the axis.

According to the above-mentioned suction housing, the liquid flowing in from the plurality of suction ports can form a swirling flow. That is, it is possible to pre-rotate the liquid flowing into the first stage of the multi-stage submersible pump. In addition, it is not necessary to add parts such as rectifying plates.

According to a second aspect of the present invention, there is provided a suction casing for a multi-stage submersible pump that handles liquid. The suction housing includes a plurality of housing main bodies extending along the axis and arranged at intervals in the circumferential direction centering on the axis. A plurality of suction ports are formed along the circumferential direction by utilizing gaps between the plurality of housing main bodies. The plurality of suction ports are formed so that the liquid flowing in from the plurality of suction ports flows in a direction different from the direction toward the axis in a cross section perpendicular to the axis to generate a swirl flow. According to the suction housing described above, the same effects as those of the first aspect 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 for each of the plurality of suction ports is rotationally symmetric 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 housings to one or both ends in the axial direction of the plurality of housing bodies. The subjects are connected to each other in the circumferential direction. According to the above aspect, since the suction housing, the intermediate housing, and the motor can be easily connected by the flange portion, assembly of the multi-stage submersible pump becomes easy.

According to a fifth aspect of the present invention, there is provided a multistage submersible pump for handling liquid. The multi-stage submersible pump has a suction casing of any one of the first to fourth forms; a motor arranged on one side in the axial direction of the suction casing; and an intermediate casing arranged in multiple stages on the other side of the suction casing, and Each segment accommodates an impeller rotationally driven by a motor. According to the above-mentioned multi-stage submersible pump, the same effect as any one of the first to fourth aspects can be achieved.

Description of drawings

FIG. 1 is a cross-sectional view showing a schematic configuration of a multi-stage submersible pump as one 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 corresponding to FIG. 3 of a suction housing as a comparative example.

Detailed ways

A. Example:

FIG. 1 is a cross-sectional view showing a schematic configuration of a multi-stage submersible pump 20 according to an embodiment of the present invention. The multi-stage submersible pump 20 (hereinafter also simply referred to as the pump 20 ) is a submersible pump for deep wells installed so that its entirety is submerged in well water in this embodiment. However, the application of the pump 20 is not limited, and the pump 20 may be any multi-stage submersible pump for processing liquid. In addition, the number of stages can be set to an arbitrary number of two or more.

As illustrated, the pump 20 includes a motor 30 , a shaft 40 , a suction housing 100 , and intermediate housings 50 , 60 , and 70 connected in multiple stages. Shaft 40 extends lengthwise inside pump 20 and has axis AL. The shaft 40 is coupled to the motor 30 via a coupling 41 .

The suction housing 100 is arranged coaxially with the axis AL. The suction housing 100 includes a suction housing main body 110 and flange portions 120 and 130 . The suction housing 100 is formed with a suction port 111 (in this embodiment, four suction ports 111a to 111d are formed as described later, but these are collectively referred to as the suction port 111 here). In the suction housing 100 described above, one end side in the direction of the axis AL is fixed to the motor 30 with a bolt 125 , and the other end side is fixed to the intermediate housing 50 with a bolt 135 .

The intermediate housings 50 , 60 , and 70 are connected in a plurality of stages in this order as viewed from the motor 30 side along the axis AL. The impellers 51 , 61 , 71 are housed inside the intermediate housings 50 , 60 , 70 , respectively. The impellers 51 , 61 , 71 are fixed around the shaft 40 . In addition, guide vanes 52 , 62 , 72 are provided inside the intermediate housings 50 , 60 , 70 so as to be connected to the impellers 51 , 61 , 71 , respectively.

In the pump 20 described above, 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 the arrow A1, and flows toward the middle housing 50 side along the axis AL. Then, the water flowing into the intermediate housing 50 of the first stage is sent to the guide vane 52 by the impeller 51 , is boosted by the guide vane 52 , and flows into the intermediate housing 60 of the second stage. Similarly, the water that has flowed into the second-stage intermediate housing 60 is sent to the guide vane 62 by the impeller 61 , is boosted by the guide vane 62 , and flows into the third-stage intermediate housing 70 . In this way, the water flowing in from the suction port 111 is sequentially boosted in each stage, sent to the rear stage, and discharged from the discharge casing (not shown) connected to the rear stage of the intermediate casing (not shown) of the last stage. .

FIG. 2 is a perspective view of the suction housing 100 . FIG. 3 is a cross-sectional view of the suction housing 100 taken along line A-A of FIG. 1 , which is orthogonal to the axis AL. As shown in FIG. 3 , the suction housing 100 includes four suction housing main bodies 110 a to 110 d in this embodiment. As shown in FIG. 2 , the suction housing main bodies 110 a to 110 d extend along the axis AL. In addition, as shown in FIG. 3 , the suction housing main bodies 110 a to 110 d are arranged at intervals in the circumferential direction around the axis AL. In this embodiment, the suction housing main bodies 110a to 110d have the same shape, and the cross-sectional shape is L-shaped. However, the shapes of the suction housing main bodies 110a to 110d can be set arbitrarily. In addition, in this embodiment, the suction housing main bodies 110a to 110d are arranged rotationally symmetrically about the axis AL.

As shown in FIG. 3 , four suction ports 111 a to 111 d are formed along the circumferential direction by utilizing gaps between adjacent suction housing main bodies 110 a to 110 d. In this embodiment, since the suction housing main bodies 110a-110d having the same shape are arranged rotationally symmetrically about the axis AL, the suction ports 111a-111d are also arranged rotationally symmetrically about the axis AL.

As shown in FIG. 3 , the suction ports 111a to 111d are formed so that the inflow directions A2 to A5 of water in the respective suction ports 111a to 111d become directions different from the direction toward the axis AL. Since the suction ports 111a to 111d are arranged rotationally symmetric about the axis AL, the inflow directions A2 to A5 of water are also rotationally symmetric about the axis AL (in this embodiment, 90° rotationally symmetric).

As shown in FIG. 3 , according to the inflow directions A2 to A5 of the suction ports 111a to 111d, the swirling flow shown by the arrow A6 can be generated by the water flowing in from the suction ports 111a to 111d. That is, the water flowing in from the suction ports 111 a to 111 d flows along the axis AL while rotating around the axis AL, and flows into the first-stage intermediate housing 50 . Therefore, the water flowing into the intermediate casing 50 of the first stage can be pre-rotated without adding components such as a rectifying plate. As a result, in all stages including the first stage, the flow of the inflowing water can be made into a swirling flow. Therefore, the efficiency of the multi-stage submersible pump provided with the rotating design impeller can be improved. In addition, in this embodiment, since the inflow directions A2 to A5 of the suction ports 111a to 111d are formed to be rotationally symmetrical about the axis AL, more uniform pre-rotation can be generated.

However, the inflow directions A2 to A5 can be set arbitrarily so that the inflow direction of water in one of the suction ports 111a to 111d is rotated by a predetermined angle around 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 in from the suction port does not become a direction that cancels out the swirling flow. In addition, the number of suction ports is not limited to four, but can be any number of two or more. In other words, the number of suction housing main bodies can be set to an arbitrary number of three or more. And, the inner surface of the suction housing main body (the inner surface forming the flow path) can be made into any shape. For example, in order to suppress the sudden change of the flow direction of water as much as possible, it can also be formed in an arc shape (for example, an arc with the axis AL as the center). part of a circle).

In addition, as shown in FIG. 2 , the suction housing 100 includes flange portions 120 and 130 . The flange portions 120 and 130 are formed at both ends of the suction housing main bodies 110a to 110d in the direction of the axis line AL, and connect the suction housing main bodies 110a to 110d in the circumferential direction. The flange portion 120 is formed at an end portion on the motor 30 side of the suction housing main bodies 110 a to 110 d. A plurality of bolt holes 121 are formed in the flange portion 120 along the circumferential direction. As described above, the motor 30 and the suction housing 100 can be fixed by the bolts 125 using the bolt holes 121 .

The flange portion 130 is formed at an end portion on the side of the intermediate housing 50 among the suction housing main bodies 110 a to 110 d. The flange portion 130 includes a first large-diameter portion 131 adjacent to the suction housing main bodies 110 a to 110 d, a second large-diameter portion 133 adjacent to the intermediate housing 50 , and a gap between the first large-diameter portion 131 and the second large-diameter portion 133 . The small diameter part 132. A plurality of bolt holes 134 are formed in the second large-diameter portion 133 along the circumferential direction. The bolt holes 134 are formed radially outward from the outer peripheral surface of the small-diameter portion 132 . As described above, the suction housing 100 and the intermediate housing 50 can be fixed with the bolts 135 using the bolt holes 134 . In addition, since the small-diameter portion 132 is formed, the insertion and movable range of the bolt tightening tool can be satisfactorily ensured, so even at the formation positions of the suction housing main bodies 110a to 110d on a plane perpendicular to the axis AL, tightening can be easily performed. Bolt 135.

In addition, as shown in FIG. 3 , notches 122 and 123 are formed in the flange portion 120 . The cutouts 122 and 123 can be used as storage spaces for power cables connected to the motor 30 .

FIG. 4 is a cross-sectional view corresponding to FIG. 3 of the suction housing 200 as a comparative example. As shown in the drawing, the suction housing 200 includes four substantially U-shaped suction housing main bodies 210a to 210d, and suction ports 211a to 211d are formed using the gaps between them. The water inflow directions A7 to A10 of the suction ports 211a to 211d are directions toward the axis line AL. In the above-mentioned suction housing 200, the swirling flow shown by the arrow A6 in FIG. Therefore, when the suction housing 200 is used in a multi-stage submersible pump having a rotary design impeller, the efficiency of the first stage is lowered compared to the case of using the suction housing 100 of this embodiment.

Although several embodiments of the present invention have been described above, the above-mentioned embodiments of the present invention are for facilitating understanding of the present invention, and do not limit the present invention. The present invention can be changed and improved without departing from the gist, and it goes without saying that the present invention includes their equivalents. In addition, each constituent element described in the technical solution and the specification can be combined or omitted within the scope of solving at least part of the above-mentioned problems, or within the scope of achieving at least part of the effects.

Explanation of reference signs

20…multi-stage submersible pump

30…motor

40…axis

41…coupling

50, 60, 70…Middle shell

51, 61, 71...Impeller

52, 62, 72... guide vane

100…suction housing

110, 110a, 110b, 110c, 110d... Suction housing body

111, 111a, 111b, 111c, 111d... Suction port

120, 130...flange

121, 134...Bolt holes

122, 123…cut

125, 135...bolts

131…The first large diameter part

132…Trail Department

133...The second largest diameter part

AL… axis

Claims (5)

1. a kind of sucking shell is the sucking shell of the multistage immersible pump for the treatment of liquid, wherein

Have along axis extend and centered on above-mentioned axis in the circumferential interval configuration multiple housing main bodies,

Using above-mentioned multiple mutual gaps of housing main body, multiple suction inlets are circumferentially formed along above-mentioned,

For above-mentioned multiple suction inlets, in the section of above-mentioned axis vertical take-off,

The inflow direction of above-mentioned multiple suction inlets aforesaid liquid of each be in from towards the different side in the direction of above-mentioned axis To,

The inflow direction of above-mentioned multiple suction inlets aforesaid liquid of each is formed as, and makes one in above-mentioned multiple suction inlets to inhale The inflow direction of the aforesaid liquid of entrance is in the direction that predetermined angular is had rotated centered on above-mentioned axis.

2. a kind of sucking shell is the sucking shell of the multistage immersible pump for the treatment of liquid, wherein

Have along axis extend and centered on above-mentioned axis in the circumferential interval configuration multiple housing main bodies,

Using above-mentioned multiple mutual gaps of housing main body, multiple suction inlets are circumferentially formed along above-mentioned,

Above-mentioned multiple suction inlets are formed as, from multiple suction inlet flow into aforesaid liquid in the section of above-mentioned axis vertical take-off It is flowed into the direction different from the direction towards the axis and generates eddy flow.

3. sucking shell according to claim 1 or 2, wherein

Above-mentioned multiple suction inlets are formed as, during the inflow direction of multiple suction inlet aforesaid liquid of each is with above-mentioned axis The heart is in rotational symmetry.

4. the sucking shell according to any one of 1~claim 3 of claim, wherein

It is also equipped with flange part, one or both ends of the flange part on the above-mentioned axis direction of above-mentioned multiple housing main bodies should Multiple housing main bodies link up in the circumferential each other.

5. a kind of multistage immersible pump is the multistage immersible pump for the treatment of liquid, has：

Sucking shell described in any one of 1~claim 4 of claim；

Motor is configured at the side on the above-mentioned axis direction of above-mentioned sucking shell；And

Intermediate case is configured to multistage in the other side of above-mentioned sucking shell, and storage rotates drive by said motor in each section Dynamic impeller.