JP2019132150A - Pump with swirl restraining device - Google Patents

Abstract

To provide a pump effectively restraining the generation of harmful underwater vortex in a suction sump without impairing the pump suction performance, also excellent in construction phase.SOLUTION: A pump 20 comprises an underwater vortex restraining device 40 fixed below a suction bell mouth 22. The underwater vortex restraining device 40 comprises: at least two first underwater vortex restraining plates 50 protruding toward the below from the suction bell mouth 22; and at least one second underwater vortex restraining plate 60 protruding toward the below from the suction bell mouth 22. The two first underwater vortex restraining plates 50 and the second underwater vortex 60 extending from the center side area of the suction bell mouth 22 toward on radial direction outside of the suction bell mouth 22, and each of the two first underwater vortex restraining plates 50 is inclined at angle of 90° to 135° viewed from the upstream side of the water flow direction with respect to the base line RL passing through the axial center O of the suction bell mouth 22 and parallel to the water flow direction within a suction sump 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pump used for the purpose of pumping water in a suction water tank, and more particularly to a pump provided with a vortex suppression device that suppresses an underwater vortex generated in the suction water tank.

  In pump facilities that drain rivers and sewage, it is required to lower the pump's operating water level due to unequal subsidence over time such as the inflow channel of the upstream flood control area. In addition, as a countermeasure against sudden rainfall such as guerrilla heavy rain in recent years, improvement of pumping capacity of the pump is also required.

  However, at the suction port of the pump, a vortex may occur on the free surface of the water in the suction water tank as the water level decreases (the water surface becomes closer to the suction port). When the vortex is drawn into the pump, it becomes an air suction vortex and air enters the pump. In particular, the continuous vortex that extends continuously from the water surface to the suction port of the pump is a harmful air suction vortex that causes abnormal vibration of the pump. If such harmful air suction vortices are generated, the pump may vibrate and fail.

  Therefore, the position of the suction port of the pump is conventionally lowered so as not to inhale such air, but when the suction port approaches the bottom surface of the suction water tank, submerged vortex from the bottom surface or side wall of the suction water tank. Is likely to occur. Further, as the pumping capacity of the pump is improved, an underwater vortex is easily generated by increasing the flow rate of water in the suction water tank. In particular, the underwater vortex that forms a cavity at the center of the vortex is a harmful underwater vortex. If such harmful underwater vortices are generated, the pump may vibrate vigorously and break down.

  Various measures such as installing a vortex prevention structure (see Patent Document 1) or connecting a suction cylinder that opens horizontally to the suction port of the pump (see Patent Document 2) as a countermeasure against such underwater vortex suppression Has been made.

JP 03-156200 A JP 2000-97199 A

  In patent document 1, in order to prevent the above-mentioned underwater vortex, providing a structure body, such as a block body, in the bottom face of a suction water tank is proposed. However, if the structure as described above is installed in the suction tank that is a civil engineering enclosure, not only the cost increases, but it is necessary to fasten the structure to the suction tank, and there are problems in strength and construction conditions (expenses). Or work schedule) may occur. Furthermore, when handling poor quality water, earth and sand may accumulate on the bottom surface of the suction tank. As a result, there is a problem that the structure installed on the bottom surface is buried and the vortex prevention function is not exhibited.

  In patent document 2, since it is the structure which covers a suction inlet with a cylinder, the suction loss of a pump becomes large. That is, there is a problem that piping loss or efficiency reduction is caused and the drainage performance of the pump is lowered.

  The present invention has been made in view of the above-mentioned conventional problems, effectively suppresses the generation of harmful underwater vortices in the suction water tank without impairing the suction performance of the pump, and is excellent in terms of construction. The purpose is to provide a pump.

  In order to achieve the above-mentioned object, one aspect of the present invention is a pump for pumping water in a suction water tank, having a main shaft, an impeller fixed to the main shaft, and a suction bell mouth opening downward. A submersible vortex suppressor fixed to a lower portion of the suction bell mouth, wherein the submerged vortex suppressor protrudes downward from the suction bell mouth. Two first underwater vortex suppression plates, and at least one second underwater vortex suppression plate protruding downward from the suction bell mouth, the at least two first underwater vortex suppression plates and at least one The second underwater vortex suppressing plate extends from a central side region of the suction bell mouth toward a radially outer side of the suction bell mouth, and the at least two first underwater vortex plates Each of the control plates is 90 ° to 135 ° when viewed from the upstream side of the water flow direction with respect to a reference line that passes through the axis of the suction bell mouth and is parallel to the water flow direction in the suction water tank. The at least two first underwater vortex suppression plates project radially outward from the lower end of the suction bell mouth, and the entire underwater vortex suppression device is connected to the shaft of the suction bell mouth. When viewed from the heart, the pump is characterized by being located inside an opening formed in the pump installation floor.

In a preferred aspect of the present invention, the first underwater vortex suppression plate has a horizontal slit extending in the horizontal direction from an outer end portion thereof.
In a preferred aspect of the present invention, the underwater vortex suppressing device further includes a third underwater vortex suppressing plate extending from the first underwater vortex suppressing plate to the upstream side or the downstream side in the water flow direction, The third underwater vortex suppressing plate is located on the radially outer side than the suction bell mouth.
In a preferred aspect of the present invention, the third underwater vortex suppressing plate has a horizontal slit extending in the horizontal direction from an outer end portion thereof.
In a preferred aspect of the present invention, the third underwater vortex suppressing plate is connected to an outer end portion of the first underwater vortex suppressing plate.
In a preferred aspect of the present invention, the first underwater vortex suppression plate has at least one vertical slit extending upward from a lower end thereof.
In a preferred aspect of the present invention, the underwater vortex suppressing device further includes a third underwater vortex suppressing plate extending from the first underwater vortex suppressing plate to the upstream side or the downstream side in the water flow direction, The third underwater vortex suppressing plate is located on the radially outer side than the suction bell mouth.
In a preferred aspect of the present invention, the underwater vortex suppressing device further includes a vertical pipe extending in a vertical direction, and the vertical pipe is fixed to an outer end portion of the first underwater vortex suppressing plate. To do.
In a preferred aspect of the present invention, the underwater vortex suppressing device further includes two arc-shaped shielding plates, and the inner surfaces of the two shielding plates are curved along the outer peripheral surface of the lower end of the suction bell mouth. The inner surfaces of the two shielding plates are fixed to outer end portions of the two first underwater vortex suppression plates, respectively.

  One aspect of the present invention is a pump for pumping water in a suction water tank, having a main shaft, an impeller fixed to the main shaft, and a suction bell mouth opening downward, and housing the impeller inside A pump casing, and an underwater vortex suppressing device fixed to a lower portion of the suction bell mouth, wherein the underwater vortex suppressing device includes at least two first underwater vortex suppressing plates protruding downward from the suction bell mouth; And at least one second underwater vortex suppression plate protruding downward from the suction bell mouth, and a plurality of horizontal pipes, wherein the at least two first underwater vortex suppression plates and the at least one second The underwater vortex suppression plate extends from a central region of the suction bell mouth toward the radially outer side of the suction bell mouth, and is that of the at least two first underwater vortex suppression plates. This is an angle of 90 ° to 135 ° when viewed from the upstream side of the water flow direction with respect to a reference line passing through the axis of the suction bell mouth and parallel to the water flow direction in the suction water tank. The plurality of horizontal pipes extend in the radial direction of the suction bell mouth and are arranged along the vertical direction with a predetermined interval between each of the plurality of horizontal pipes. The underwater vortex suppressing plate is fixed to the outer end of the underwater vortex suppressing plate, and the entire underwater vortex suppressing device is located inside the opening formed in the pump installation floor when viewed from the axial center of the suction bell mouth. It is a pump characterized by having.

  In a preferred aspect of the present invention, the ends of the plurality of horizontal pipes are bent toward the upstream side or the downstream side in the water flow direction.

  One aspect of the present invention is a pump for pumping water in a suction water tank, having a main shaft, an impeller fixed to the main shaft, and a suction bell mouth opening downward, and housing the impeller inside A pump casing and an underwater vortex suppressing device fixed to a lower portion of the suction bell mouth, wherein the underwater vortex suppressing device includes two first underwater vortex suppression plates protruding downward from the suction bell mouth; Two second underwater vortex suppression plates protruding downward from the suction bell mouth, and the two first underwater vortex suppression plates and the two second underwater vortex suppression plates are the suction bells. Extending from the inside of the mouse toward the outside of the suction bell mouth, the two first underwater vortex suppression plates project outward from the lower end of the suction bell mouth, and the axial center of the suction bell mouth From the above Each of the two straight lines extending to the intersection of the first submerged vortex suppression plate and the lower end of the suction bell mouth is a reference parallel to the flow direction of the water in the suction tank passing through the axis of the suction bell mouth. When viewed from the upstream side of the flow direction of the water with respect to the line, an angle of 90 ° to 135 ° is formed, and when the entire underwater vortex suppressing device is viewed from the axis of the suction bell mouth, It is a pump characterized by being located inside the opening formed in the pump installation floor.

  In a preferred aspect of the present invention, the two first underwater vortex suppression plates are perpendicular to the reference line.

  Since the above-described underwater vortex suppressing device causes almost no suction loss, the underwater vortex can be suppressed without reducing the pumping capacity of the pump. Further, since the underwater vortex suppressing device is installed in the pump casing, it is not necessary to fasten the underwater vortex suppressing device to the suction water tank, and the construction surface is excellent.

It is a mimetic diagram showing one embodiment of a pump provided with an underwater vortex control device. It is a schematic diagram which shows the underwater vortex which generate | occur | produces in a suction water tank. It is the figure which looked at the underwater vortex shown in FIG. 2 from the top. It is a figure which shows the example of each dimension linked | related with the pump aperture. It is the figure which looked at the pump and suction water tank shown in FIG. 4 from the top. It is a side view which shows an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 6 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 8 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 10 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 12 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 14 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 16 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 18 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 20 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 22 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 24 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 26 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 28 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 30 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 32 from the bottom. It is a side view which shows other embodiment of an underwater vortex suppression apparatus. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 34 from the bottom. It is a schematic diagram which shows other embodiment of a pump. It is a side view which shows the underwater vortex suppression apparatus shown in FIG. It is the figure which looked at the underwater vortex suppression apparatus shown in FIG. 37 from the bottom.

  Embodiments of the present invention will be described below with reference to the drawings. Although the embodiment described below relates to a vertical shaft pump, the present invention is not limited to these embodiments, and can also be used for a horizontal shaft pump. Furthermore, the present invention can also be used for a column pipe submersible pump. Drawing 1 is a mimetic diagram showing one embodiment of a pump provided with an underwater vortex control device. As shown in FIG. 1, the pump 20 is connected to a main shaft 32 extending in the vertical direction, an impeller 31 fixed to the main shaft 32, a pump casing 27 that houses the impeller 31 inside, and an upper end of the pump casing 27. And a discharge bend pipe 30 connected to the upper end of the pumping pipe 28. The pump casing 27 is suspended in the suction water tank 1 by a pumping pipe 28. The pump casing 27 includes a suction bell mouth 22, an impeller casing 21, and a discharge bowl 24. The upper end of the discharge bowl 24 is connected to the lower end of the pumping pipe 28. The suction bell mouth 22 has a suction port 22a opened downward. The upper end of the suction bell mouth 22 is connected to the lower end of the impeller casing 21. The impeller 31 is accommodated in the impeller casing 21 and the discharge bowl 24.

  The pumping pipe 28 extends downward through the opening 5 formed in the pump installation floor 2 constituting the upper wall of the suction water tank 1. A suspension pipe 33 is fixed to the upper end of the pumping pipe 28. The suspension pipe 33 is fixed to a pump base 35 installed on the pump installation floor 2. The pumping pipe 28 is fixed to the pump installation floor 2 via the hanging pipe 33 and the pump base 35. The main shaft 32 extends in the vertical direction through the discharge curved pipe 30, the pumping pipe 28, and the pump casing 27, and the lower end thereof is located in the pump casing 27.

  The main shaft 32 is rotatably supported by an outer bearing 45 and an underwater bearing 41. The outer bearing 45 is fixed to the upper part of the discharge curved pipe 30 and supports the upper part of the main shaft 32. The underwater bearing 41 is accommodated in the discharge bowl 24 and supports the lower portion of the main shaft 32. An inner bowl 25 is disposed inside the discharge bowl 24, and the inner bowl 25 is connected to the discharge bowl 24 by a plurality of guide vanes 37. The underwater bearing 41 is fixed to the inner peripheral surface of the inner bowl 25 via a support member 41a.

  The main shaft 32 protrudes upward from the discharge curved pipe 30 and is connected to a motor (not shown) such as a motor. The main shaft 32 and the impeller 31 are configured to rotate by this prime mover. The plurality of guide vanes 37 are disposed above (discharge side) the impeller 31. A water flow path is formed between the inner peripheral surface of the discharge bowl 24 and the outer peripheral surface of the inner bowl 25. When the impeller 31 rotates, the water in the suction water tank 1 is sucked from the suction port 22 a of the suction bell mouth 22. The water is transferred to a discharge pipe (not shown) through the discharge bowl 24, the pumping pipe 28 and the discharge bent pipe 30 by the rotation of the impeller 31.

  The pump 20 further includes an underwater vortex suppressing device 40 that suppresses the underwater vortex. The underwater vortex suppressing device 40 is fixed to the lower part of the suction bell mouth 22. In the present embodiment, the underwater vortex suppressing device 40 is disposed below the impeller 31. The underwater vortex suppressing device 40 includes a plurality of first underwater vortex suppressing plates 50, a second underwater vortex suppressing plate 60, and a plurality of third underwater vortex suppressing plates 70. In FIG. 1, only one of the plurality of first underwater vortex suppression plates 50 is illustrated, and only one of the plurality of third underwater vortex suppression plates 70 is displayed.

  The first underwater vortex suppression plate 50, the second underwater vortex suppression plate 60, and the third underwater vortex suppression plate 70 are flat members. The first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 are fixed to the lower part of the suction bell mouth 22 and protrude downward from the suction bell mouth 22. In the present embodiment, the upper ends of the first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 are higher than the lower end of the suction bell mouth 22 and lower than the impeller 31.

  FIG. 2 is a schematic view showing an underwater vortex generated in the suction water tank 1, and FIG. 3 is a view of the underwater vortex shown in FIG. 2 as viewed from above. In FIG. 2, the underwater vortex suppressing device 40 is not provided. As shown in FIGS. 2 and 3, the underwater vortex includes an underwater vortex 8 generated from the bottom surface of the suction water tank 1, an underwater vortex 9 generated from the side wall of the suction water tank 1, and an underwater vortex generated from the rear wall of the suction water tank 1. 10 is comprised. When water in the suction water tank 1 is sucked from the suction port 22 a of the suction bell mouth 22, a swirling flow is generated between the suction bell mouth 22 and the bottom surface of the suction water tank 1. The underwater vortex 8 is formed by the development of this swirling flow. The underwater vortex 8 is generated from the bottom surface of the suction water tank 1 and extends to the inside of the suction bell mouth 22.

  When water in the suction water tank 1 is sucked from the suction port 22a of the suction bell mouth 22, a swirling flow is also generated between the suction bell mouth 22 and the side wall and the rear wall of the suction water tank 1. The underwater vortices 9 and 10 are formed by the development of a swirling flow generated between the suction bell mouth 22 and the side wall and the rear wall of the suction water tank 1. The underwater vortexes 9 and 10 are generated from the side wall and the rear wall of the suction water tank 1 and extend to the inside of the suction bell mouth 22. The underwater vortices 8 and 9 described above are likely to occur when the suction bell mouth 22 is located near the bottom surface of the suction water tank 1. The underwater vortex 10 is likely to occur when the rear wall of the suction water tank 1 is close to the suction bell mouth 22.

  As shown in FIG. 3, it is generally known that the underwater vortex 9 is often generated in the vicinity of the straight lines PL and PL '. The straight lines PL and PL ′ are at an angle of 90 ° to 135 ° with respect to the reference line RL from the upstream side in the water flow direction in the suction water tank 1 and pass through the axis O ′ of the suction bell mouth 22. It is a straight line. The reference line RL is a straight line that passes through the axis O ′ of the suction bell mouth 22 and is parallel to the flow direction of the water in the suction water tank 1. The straight lines PL and PL ′ shown in FIG. 3 are at an angle of 120 ° with respect to the reference line RL as viewed from the upstream side of the water flow direction in the suction water tank 1, and the axis O ′ of the suction bell mouth 22 is defined. It is a straight line that passes through.

  FIG. 4 is a diagram illustrating an example of each dimension associated with the pump diameter, and FIG. 5 is a diagram of the pump 20 and the suction water tank 1 illustrated in FIG. 4 as viewed from above. As shown in FIG. 4, when the pump diameter (in this embodiment, the diameter on the discharge side of the pump casing 27) is d, from the lower end of the suction bell mouth 22 (that is, the lower end of the pump casing 27) to the bottom surface of the suction water tank 1. The distance is 0.5d or more, and is in the range of 0.75d to 1.0d as an example. The distance from the center of the pump 20 (axial center O of the main shaft 32) to the rear wall of the suction water tank 1 is 1.5 d or less. The diameter of the opening 5 is a value that is substantially determined by the pump diameter d, but is in the range of 1.6d to 2.1d in one embodiment. As shown in FIG. 5, the channel width of the suction water tank 1 is generally about 3.0d. When designed with these dimensions, the lowest water level LWL of the suction water tank 1 in which the pump 20 can be operated as an underwater vortex suppression effect can be lowered by about 0.5d to 0.9d as compared with a conventional pump.

  6 is a side view showing the underwater vortex suppressing device 40, and FIG. 7 is a view of the underwater vortex suppressing device 40 shown in FIG. 6 as viewed from below. In the present embodiment, the plurality of first underwater vortex suppression plates 50 are two first underwater vortex suppression plates 50, and the plurality of third underwater vortex suppression plates 70 are two third underwater vortex suppression plates 50. It is a plate 70. The amount of protrusion of the first underwater vortex suppression plate 50 and the second underwater vortex suppression plate 60 from the lower end of the suction bell mouth 22 is represented by h1. The first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 extend downward in the vertical direction.

  The two first underwater vortex suppression plates 50 and the second underwater vortex suppression plate 60 extend from the central region of the suction bell mouth 22 toward the radially outer side of the suction bell mouth 22. In the present embodiment, the two first underwater vortex suppression plates 50 and the second underwater vortex suppression plate 60 extend from the axial center O ′ of the suction bell mouth 22 toward the radially outer side of the suction bell mouth 22. . One ends (inner ends) of the two first underwater vortex suppression plates 50 and the second underwater vortex suppression plate 60 are fixed to each other on the axis O ′ of the suction bell mouth 22. In the present embodiment, the axis O ′ of the suction bell mouth 22 corresponds to the axis O of the main shaft 32 (see FIG. 1).

  The first underwater vortex suppression plate 50 protrudes radially outward from the lower end of the suction bell mouth 22. The other end (outer end portion) of the first underwater vortex suppression plate 50 is radially outward of the suction bell mouth 22 and the opening 5 of the pump installation floor 2 when viewed from the axial center O ′ of the suction bell mouth 22. Located inside. The second underwater vortex suppression plate 60 extends to the lower end of the suction bell mouth 22, and the other end (outer end portion) extends downward from the lower end of the suction bell mouth 22 in the vertical direction. The horizontal length L1 of the first underwater vortex suppressing plate 50 is longer than the radius of the lower end of the suction bell mouth 22 and shorter than the radius of the opening 5 of the pump installation floor 2. The horizontal length L2 of the second underwater vortex suppressing plate 60 is approximately the same as the radius of the lower end of the suction bell mouth 22.

  The two first underwater vortex suppression plates 50 are arranged symmetrically with respect to the reference line RL. One of the two first underwater vortex suppression plates 50 is inclined with respect to the reference line RL at an angle θ1 when viewed from the upstream side of the water flow direction in the suction water tank 1. The other one of the two first underwater vortex suppression plates 50 is inclined at an angle θ2 with respect to the reference line RL as viewed from the upstream side in the water flow direction in the suction water tank 1. The second underwater vortex suppressing plate 60 is disposed on the reference line RL on the upstream side in the water flow direction in the suction water tank 1 when viewed from the axis O ′ of the suction bell mouth 22. In the present embodiment, the angles θ1 and θ2 are 120 °.

  The first submersible vortex suppression plate 50 and the second submersible vortex suppression plate 60 are configured such that when the water in the suction water tank 1 is sucked from the suction port 22 a of the suction bell mouth 22, the suction bell mouth 22 and the bottom surface of the suction water tank 1. The swirling flow generated between the two can be obstructed and the momentum of the swirling flow can be reduced. As a result, the underwater vortex suppressing device 40 including the first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 can suppress the underwater vortex 8 generated from the bottom surface of the suction water tank 1. . In this way, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface of the suction water tank 1.

  From the viewpoint of suppressing the underwater vortex 8, the first underwater vortex suppression plate 50 and the second underwater vortex suppression plate 60 need to have a certain height. Specifically, the protrusion amount h1 of the first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 from the lower end of the suction bell mouth 22 is 0.1d to 0.7d, where d is the pump diameter. Within the range of

  As described above, the first underwater vortex suppressing plate 50 extends radially outward from the axis O ′ of the suction bell mouth 22 and flows in the suction water tank 1 with respect to the reference line RL. It is inclined at an angle of 120 ° when viewed from the upstream side. As described above, it is known that the underwater vortex 9 often occurs in the vicinity of the straight lines PL and PL 'shown in FIG. Further, since the first underwater vortex suppression plate 50 projects radially outward from the lower end of the suction bell mouth 22, the first underwater vortex suppression plate 50 is located between the suction bell mouth 22 and the side wall of the suction water tank 1. Can prevent the swirling flow generated in the flow, and weaken the momentum of the swirling flow. As a result, the underwater vortex suppressing device 40 provided with such a first underwater vortex suppressing plate 50 can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1. In this way, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the side wall of the suction water tank 1.

  In the present embodiment, the angles θ1 and θ2 are 120 °, but the angles θ1 and θ2 are not limited to 120 °, and may be selected within the range of 90 ° to 135 ° depending on the drifting situation of the aquarium flow. Also in this case, the first underwater vortex suppression plate 50 can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1.

  The first underwater vortex suppressing plate 50 of the present embodiment has a lateral slit 53 extending in the horizontal direction from the outer end portion thereof. The swirl flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is further weakened by passing through the transverse slit 53. As a result, the first underwater vortex suppression plate 50 provided with such a lateral slit 53 can further suppress the underwater vortex 9 generated from the side wall of the suction water tank 1.

  The two third underwater vortex suppression plates 70 extend from the two first underwater vortex suppression plates 50 to the upstream side of the water flow direction in the suction water tank 1, respectively. The third underwater vortex suppression plate 70 is located radially outward from the suction bell mouth 22. Specifically, the third underwater vortex suppression plate 70 is connected to the outer end portion of the first underwater vortex suppression plate 50, and the third underwater vortex suppression plate 70 is the first underwater vortex suppression plate 70. It extends from the outer end portion of 50 to the upstream side in the water flow direction in the suction water tank 1. The third underwater vortex suppressing plate 70 is disposed perpendicular to the first underwater vortex suppressing plate 50. The height of the third underwater vortex suppression plate 70 (the vertical length of the third underwater vortex suppression plate 70) is the suction bell mouth of the first underwater vortex suppression plate 50 and the second underwater vortex suppression plate 60. 22 is equal to the protruding amount h1 from the lower end.

  Such a third underwater vortex suppression plate 70 can also disturb the swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1, and can weaken the momentum of this swirling flow. As a result, the underwater vortex suppressing device 40 including the third underwater vortex suppressing plate 70 can further suppress the underwater vortex 9 generated from the side wall of the suction water tank 1.

  The 3rd underwater vortex suppression board 70 has the horizontal slit 73 extended in the horizontal direction from the outer side edge part. The swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is further weakened by passing through the transverse slit 73. As a result, the third underwater vortex suppressing plate 70 provided with such a lateral slit 73 can further suppress the underwater vortex 9 generated from the side wall of the suction water tank 1.

  In the present embodiment, the underwater vortex suppression device 40 includes two first underwater vortex suppression plates 50, but the number of the first underwater vortex suppression plates 50 is not limited to the present embodiment. In one embodiment, the underwater vortex suppression device 40 may include three or more first underwater vortex suppression plates 50. Moreover, in this embodiment, although the underwater vortex suppression apparatus 40 is provided with the one 2nd underwater vortex suppression board 60, the number of the 2nd underwater vortex suppression plates 60 is not limited to this embodiment. In one embodiment, the underwater vortex suppression device 40 may include two or more second underwater vortex suppression plates 60. Furthermore, in one embodiment, the third underwater vortex suppression plate 70 may be formed integrally with the first underwater vortex suppression plate 50. Furthermore, in one embodiment, the 3rd underwater vortex suppression board 70 may be extended from the 1st underwater vortex suppression board 50 to the downstream of the flow direction of the water in the suction water tank 1, respectively.

  FIG. 8 is a side view showing another embodiment of the underwater vortex suppressing device 40, and FIG. 9 is a view of the underwater vortex suppressing device 40 shown in FIG. 8 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The first underwater vortex suppressing plate 50 of the present embodiment does not have the horizontal slit 53. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1. In one embodiment, the third underwater vortex suppression plate 70 may not have the lateral slit 73.

  FIG. 10 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 11 is a view of the underwater vortex suppressing device 40 shown in FIG. 10 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppressing device 40 of the present embodiment does not include the third underwater vortex suppressing plate 70, and the first underwater vortex suppressing plate 50 does not have the lateral slit 53. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  12 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 13 is a view of the underwater vortex suppressing device 40 shown in FIG. 12 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppressing device 40 of the present embodiment does not include the third underwater vortex suppressing plate 70. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  14 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 15 is a view of the underwater vortex suppressing device 40 shown in FIG. 14 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppression device 40 of the present embodiment includes two first underwater vortex suppression plates 50 and two second underwater vortex suppression plates 60.

  The two first underwater vortex suppression plates 50 are arranged symmetrically with respect to the reference line RL. In the present embodiment, the angles θ1 and θ2 are 135 °. The two second underwater vortex suppression plates 60 are arranged symmetrically with respect to the reference line RL, and when viewed from the axis O ′ of the suction bell mouth 22, the upstream side in the water flow direction in the suction water tank 1. Is arranged. As shown in FIG. 15, in the present embodiment, two first underwater vortex suppression plates 50 and two second underwater vortex suppression plates 60 are 90 ° around the axis O ′ of the suction bell mouth 22. The inner ends of the two first underwater vortex suppressing plates 50 and the two second underwater vortex suppressing plates 60 are fixed to each other on the axis O ′ of the suction bell mouth 22. Has been.

  The underwater vortex suppressing device 40 of the present embodiment does not include the third underwater vortex suppressing plate 70. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  16 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 17 is a view of the underwater vortex suppressing device 40 shown in FIG. 16 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The third underwater vortex suppression plate 70 of the present embodiment is connected to the surface of the first underwater vortex suppression plate 50, and the third underwater vortex suppression plate 70 is the surface of the first underwater vortex suppression plate 50. To the upstream side of the water flow direction in the suction tank 1. The third underwater vortex suppression plate 70 is located radially outward from the suction bell mouth 22. The third underwater vortex suppressing plate 70 is disposed perpendicular to the first underwater vortex suppressing plate 50. The 3rd underwater vortex suppression board 70 has the horizontal slit 73 extended in the horizontal direction from the outer side edge part.

  The first underwater vortex suppressing plate 50 of the present embodiment does not have the horizontal slit 53. Also in this embodiment, the 3rd underwater vortex suppression board 70 can interrupt the swirl flow which generate | occur | produces between the suction bell mouth 22 and the side wall of the suction water tank 1, and can weaken the force of this swirl flow. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1. The length of the third underwater vortex suppression plate 70 is not limited to the embodiment shown in FIG. In one embodiment, the third underwater vortex suppressing plate 70 may extend to the upstream side of the water flow direction in the suction water tank 1 when viewed from the axial center O ′ of the suction bell mouth 22. Furthermore, in one embodiment, the underwater vortex suppression device 40 may include two or more second underwater vortex suppression plates 60.

  18 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 19 is a view of the underwater vortex suppressing device 40 shown in FIG. 18 as viewed from below. The configuration related to the present embodiment that is not particularly described is the same as the embodiment described with reference to FIGS. 16 and 17, and thus redundant description thereof is omitted. The first underwater vortex suppressing plate 50 of the present embodiment has a lateral slit 53. Also in this embodiment, the swirl flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is weakened by passing through the transverse slit 53. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  The lateral slit 53 of the first underwater vortex suppression plate 50 shown in FIG. 18 is shorter than the lateral slit 53 of the first underwater vortex suppression plate 50 shown in FIG. As shown in FIG. 18, the horizontal slit 53 of the present embodiment extends from the outer end of the first underwater vortex suppression plate 50 to the third underwater vortex suppression plate 70, but the length of the horizontal slit 53 is It is not limited to this embodiment. In one embodiment, the lateral slit 53 may extend inward from the outer end of the first underwater vortex suppressing plate 50 beyond the third underwater vortex suppressing plate 70.

  20 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 21 is a view of the underwater vortex suppressing device 40 shown in FIG. 20 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The third underwater vortex suppression plate 70 of the present embodiment has an L-shaped horizontal cross-sectional shape. One surface of the third underwater vortex suppression plate 70 is fixed to the surface of the first underwater vortex suppression plate 50, and the other surface of the third underwater vortex suppression plate 70 is outside the first underwater vortex suppression plate 50. It extends from the end to the upstream side in the direction of water flow in the suction tank 1. The third underwater vortex suppressing plate 70 of the present embodiment does not have the horizontal slit 73.

  The first underwater vortex suppressing plate 50 of the present embodiment does not have the horizontal slit 53. Also in this embodiment, the 3rd underwater vortex suppression board 70 can interrupt the swirl flow which generate | occur | produces between the suction bell mouth 22 and the side wall of the suction water tank 1, and can weaken the force of this swirl flow. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  22 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 23 is a view of the underwater vortex suppressing device 40 shown in FIG. 22 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppressing device 40 of the present embodiment does not include the third underwater vortex suppressing plate 70, and the first underwater vortex suppressing plate 50 does not have the lateral slit 53. The first underwater vortex suppression plate 50 of the present embodiment has a plurality of vertical slits 55 extending upward from the lower end thereof. The swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is weakened by passing through the vertical slit 55. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1. The number of the vertical slits 55 is not limited to this embodiment. The first underwater vortex suppressing plate 50 may have one vertical slit 55 or may have two or more vertical slits 55.

  24 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 25 is a view of the underwater vortex suppressing device 40 shown in FIG. 24 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppressing device 40 of the present embodiment does not include the third underwater vortex suppressing plate 70, and the first underwater vortex suppressing plate 50 does not have the lateral slit 53. The underwater vortex suppressing device 40 of the present embodiment further includes two vertical pipes 57 extending in the vertical direction, and the first underwater vortex suppressing plate 50 has a vertical slit 55 extending upward from the lower end thereof. . The two vertical pipes 57 are fixed to the outer ends of the two first underwater vortex suppression plates 50, respectively.

  The swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is weakened by passing through the vertical slit 55. Further, the vertical pipe 57 can obstruct the swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1, and can weaken the momentum of the swirling flow. As a result, the underwater vortex suppressing device 40 can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  Although the 1st underwater vortex suppression board 50 of this embodiment has the one vertical slit 55, the number of the vertical slits 55 is not limited to this embodiment. The first underwater vortex suppression plate 50 may have two or more vertical slits 55.

  26 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 27 is a view of the underwater vortex suppressing device 40 shown in FIG. 26 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The first underwater vortex suppressing plate 50 of the present embodiment does not have the horizontal slit 53. The first underwater vortex suppression plate 50 has a vertical slit 55 extending upward from its lower end.

  The third underwater vortex suppression plate 70 is connected to the outer end of the first underwater vortex suppression plate 50. The third underwater vortex suppressing plate 70 extends from the outer end of the first underwater vortex suppressing plate 50 to the upstream side in the water flow direction in the suction water tank 1. The third underwater vortex suppressing plate 70 is disposed perpendicular to the first underwater vortex suppressing plate 50. The third underwater vortex suppressing plate 70 of the present embodiment does not have the horizontal slit 73.

  The swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is weakened by passing through the vertical slit 55. Further, the third underwater vortex suppression plate 70 can block the swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1, and can weaken the momentum of the swirling flow. As a result, the underwater vortex suppressing device 40 can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  Although the 1st underwater vortex suppression board 50 of this embodiment has the one vertical slit 55, the number of the vertical slits 55 is not limited to this embodiment. The first underwater vortex suppression plate 50 may have two or more vertical slits 55.

  FIG. 28 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 29 is a view of the underwater vortex suppressing device 40 shown in FIG. 28 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppression device 40 according to the present embodiment includes two first underwater vortex suppression plates 50, two second underwater vortex suppression plates 60, and two shielding plates 80. The first underwater vortex suppressing plate 50 of the present embodiment does not have the horizontal slit 53.

  The two second underwater vortex suppression plates 60 are arranged symmetrically with respect to the reference line RL, and when viewed from the axis O ′ of the suction bell mouth 22, the upstream side in the water flow direction in the suction water tank 1. Is arranged. The inner ends of the two first underwater vortex suppression plates 50 and the two second underwater vortex suppression plates 60 are fixed to each other on the axis O ′ of the suction bell mouth 22.

  The shielding plate 80 has an arc shape. More specifically, the shielding plate 80 has an arcuate horizontal cross-sectional shape. The two shielding plates 80 extend in the vertical direction, and the inner surface of the shielding plate 80 is curved along the outer peripheral surface of the lower end of the suction bell mouth 22. The inner surfaces of the two shielding plates 80 are fixed to the outer ends of the two first underwater vortex suppression plates 50, respectively. The shielding plate 80 obstructs the swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1, and can weaken the momentum of the swirling flow. As a result, the underwater vortex suppressing device 40 including such a shielding plate 80 can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  30 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 31 is a view of the underwater vortex suppressing device 40 shown in FIG. 30 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppressing device 40 of the present embodiment includes two first underwater vortex suppressing plates 50, two second underwater vortex suppressing plates 60, and a plurality of horizontal pipes 58.

  One of the two second underwater vortex suppression plates 60 is disposed on a reference line RL on the upstream side in the water flow direction in the suction water tank 1 when viewed from the axis O ′ of the suction bell mouth 22. ing. The other one of the two second underwater vortex suppression plates 60 is on a reference line RL on the downstream side in the water flow direction in the suction water tank 1 when viewed from the axis O ′ of the suction bell mouth 22. Is arranged.

  The first underwater vortex suppressing plate 50 of the present embodiment does not have the horizontal slit 53. The horizontal length L3 of the first underwater vortex suppressing plate 50 of the present embodiment may be shorter than the horizontal length L1 of the first underwater vortex suppressing plate 50 shown in FIGS. The first underwater vortex suppressing plate 50 does not have to protrude radially outward from the lower end of the suction bell mouth 22.

  The plurality of horizontal pipes 58 extend in the radial direction of the suction bell mouth 22 and are arranged along the vertical direction at regular intervals. The plurality of horizontal pipes 58 are fixed to the outer end of the first underwater vortex suppression plate 50. In the present embodiment, two horizontal pipes 58 are fixed to each of the outer end portions of the two first underwater vortex suppression plates 50. The underwater vortex suppressing device 40 of the present embodiment further includes a plurality of pipe slits 58a. The pipe slit 58 a is a space surrounded by two horizontal pipes 58 arranged along the vertical direction and the outer end of the first underwater vortex suppressing plate 50.

  The swirling flow generated between the suction bell mouth 22 and the side wall of the suction water tank 1 is weakened by passing through the pipe slit 58a. Further, the horizontal pipe 58 can obstruct the above-mentioned swirling flow and weaken the momentum of the swirling flow. As a result, the underwater vortex suppressing device 40 including the horizontal pipe 58 and the pipe slit 58 a can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  The number of horizontal pipes 58 is not limited to this embodiment. In one embodiment, three or more horizontal pipes 58 may be fixed to each of the outer ends of the two first underwater vortex suppression plates 50. As an example, when the pump diameter is d, the diameter of the horizontal pipe 58 is preferably 0.1d to 0.3d.

  32 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 33 is a view of the underwater vortex suppressing device 40 shown in FIG. 32 as viewed from below. The configuration related to the present embodiment that is not particularly described is the same as the embodiment described with reference to FIGS. 30 and 31, and thus redundant description thereof is omitted. The horizontal pipe 58 of the present embodiment is bent toward the downstream side of the water flow direction in the suction water tank 1. In the present embodiment, the horizontal pipe 58 is bent at a substantially right angle. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1. In this embodiment, the angles θ1 and θ2 are 105 °, but the angles θ1 and θ2 are not limited to 105 ° and may be selected within a range of 90 ° to 135 °. As an example, when the pump bore is d, the length L4 from the tip of the horizontal pipe 58 to the corner of the horizontal pipe 58 is preferably 0.2d to 0.5d. In one embodiment, the horizontal pipe 58 may be bent toward the upstream side of the water flow direction in the suction water tank 1.

  FIG. 34 is a side view showing still another embodiment of the underwater vortex suppressing device 40, and FIG. 35 is a view of the underwater vortex suppressing device 40 shown in FIG. 34 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The underwater vortex suppression device 40 of the present embodiment includes two first underwater vortex suppression plates 50 and two second underwater vortex suppression plates 60.

  The two first underwater vortex suppression plates 50 are arranged symmetrically with respect to the reference line RL and are perpendicular to the reference line RL. The two first underwater vortex suppression plates 50 and the two second underwater vortex suppression plates 60 extend from the inside of the suction bell mouth 22 toward the outside of the suction bell mouth 22. The two second underwater vortex suppression plates 60 are arranged on the reference line RL. In the present embodiment, the inner ends of the two first underwater vortex suppression plates 50 and the two second underwater vortex suppression plates 60 are fixed to each other at an intersection X on the reference line RL. The two first underwater vortex suppression plates 50 and the two second underwater vortex suppression plates 60 extend from the intersection X toward the outside of the suction bell mouth 22.

  The first underwater vortex suppression plate 50 projects outward from the lower end of the suction bell mouth 22. Two straight lines YL and YL ′ extending from the axial center O ′ of the suction bell mouth 22 to the intersections Y and Y ′ between the two first underwater vortex suppression plates 50 and the lower end of the suction bell mouth 22 are on the reference line RL. On the other hand, when viewed from the upstream side of the water flow direction in the suction water tank 1, angles of θ3 and θ4 are formed. In the present embodiment, the angles θ3 and θ4 are 120 °. The second underwater vortex suppression plate 60 extends to the lower end of the suction bell mouth 22, and its outer end extends vertically downward from the lower end of the suction bell mouth 22.

  When viewed from the intersection X, the horizontal length L5 of the second underwater vortex suppression plate 60 arranged on the upstream side in the water flow direction in the suction water tank 1 is larger than the radius of the lower end of the suction bell mouth 22. Long and shorter than the diameter of the lower end of the suction bell mouth 22. When viewed from the intersection point X, the horizontal length L6 of the second underwater vortex suppression plate 60 arranged on the downstream side in the water flow direction in the suction water tank 1 is larger than the radius of the lower end of the suction bell mouth 22. short.

  Since each of the two first underwater vortex suppression plates 50 is on a straight line YL, YL ′ that forms an angle of 120 ° with the reference line RL, such a first underwater vortex suppression plate 50 is a suction bell mouth. Thus, the swirl flow generated between 22 and the side wall of the suction water tank 1 can be obstructed, and the underwater vortex 9 generated near the straight lines PL and PL ′ (see FIG. 3) can be suppressed. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  In the present embodiment, the angles θ3 and θ4 are 120 °, but the angles θ3 and θ4 are not limited to 120 ° and may be selected within a range of 90 ° to 135 °. Also in this case, the first underwater vortex suppression plate 50 can suppress the underwater vortex 9 generated from the side wall of the suction water tank 1. In one embodiment, the two first underwater vortex suppression plates 50 may be integrally formed, and the second underwater vortex suppression plate 60 may be fixed to the surface of the first underwater vortex suppression plate 50. . Furthermore, in one embodiment, the two second underwater vortex suppression plates 60 may be integrally formed, and the second underwater vortex suppression plate 60 may be fixed to the surface of the first underwater vortex suppression plate 50. Good.

  FIG. 36 is a schematic diagram showing another embodiment of the pump 20. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. The lower end of the main shaft 32 of the present embodiment is located below the discharge bowl 24 and the impeller 31. The underwater bearing 41 is disposed below the discharge bowl 24 and the impeller 31 and supports the lower end of the main shaft 32. The underwater bearing 41 is accommodated in the underwater bearing case 42. The underwater bearing case 42 is fixed to the inner peripheral surface of the suction bell mouth 22 via a plurality of first underwater vortex suppression plates 50 and second underwater vortex suppression plates 60, and is concentric with the axis of the main shaft 32. Is arranged. The underwater bearing 41 of the present embodiment is disposed below the discharge bowl 24 and the impeller 31. In the present embodiment, the underwater bearing 41 can be inspected and replaced without lifting the pump 20 from the suction water tank 1.

  37 is a side view showing the underwater vortex suppressing device 40 shown in FIG. 36, and FIG. 38 is a view of the underwater vortex suppressing device 40 shown in FIG. 37 as viewed from below. The configuration relating to the present embodiment that is not particularly described is the same as that described with reference to FIGS. Inner ends of the first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 of the present embodiment are fixed to the outer peripheral surface of the underwater bearing case 42. The first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 extend from the outer peripheral surface of the underwater bearing case 42 toward the radially outer side of the suction bell mouth 22. The horizontal length L1 of the first underwater vortex suppressing plate 50 is shorter than the radius of the opening 5. The horizontal length L <b> 2 of the second underwater vortex suppressing plate 60 is shorter than the lower end radius of the suction bell mouth 22. Also in this embodiment, the underwater vortex suppressing device 40 can suppress the generation of harmful underwater vortices from the bottom surface and side walls of the suction water tank 1.

  The underwater vortex suppressing device 40 of each embodiment described with reference to FIGS. 8 to 33 can be applied to the pump 20 described with reference to FIGS. 36 to 38. Also in this case, the inner ends of the first underwater vortex suppressing plate 50 and the second underwater vortex suppressing plate 60 are fixed to the outer peripheral surface of the underwater bearing case 42. The horizontal length L1 of the first underwater vortex suppressing plate 50 is shorter than the radius of the opening 5. The horizontal length L <b> 2 of the second underwater vortex suppressing plate 60 is shorter than the lower end radius of the suction bell mouth 22.

  The entire underwater vortex suppressing device 40 of each embodiment described above is located inside the opening 5 formed in the pump installation floor 2 when viewed from the axial center O ′ of the suction bell mouth 22. Therefore, when the maintenance or repair of the pump 20 is performed, the entire pump 20 can be pulled up through the opening 5.

  Since the underwater vortex suppressing device 40 of each embodiment described above causes almost no suction loss, the underwater vortex 8 generated from the bottom surface of the suction water tank 1 and the side wall of the suction water tank 1 without reducing the pumping capacity of the pump 20. The generated underwater vortex 9 can be suppressed. Moreover, since the underwater vortex suppressing device 40 is installed in the pump casing 27, it is not necessary to fasten the underwater vortex suppressing device 40 to the suction water tank 1, and the construction is excellent.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in the widest scope according to the technical idea defined by the claims.

DESCRIPTION OF SYMBOLS 1 Suction water tank 2 Pump installation floor 5 Opening 8 Underwater vortex 9 Underwater vortex 10 Underwater vortex 20 Pump 21 Impeller casing 22 Suction bell mouth 22a Suction port 24 Discharge bowl 25 Inner bowl 27 Pump casing 28 Pump pipe 30 Discharge curved pipe 31 Impeller 32 Main shaft 33 Suspension pipe 35 Pump base 37 Guide vane 40 Underwater vortex suppression device 41 Underwater bearing 42 Underwater bearing case 45 Outer bearing 50 First underwater vortex suppression plate 53 Horizontal slit 55 Vertical slit 57 Vertical pipe 58 Horizontal pipe 58a Pipe slit 60 Second underwater vortex suppression plate 70 Third underwater vortex suppression plate 73 Horizontal slit 80 Shielding plate

Claims (13)

In the pump that pumps up the water in the suction tank,
The spindle,
An impeller fixed to the main shaft;
A pump casing having a suction bell mouth that opens downward, and containing the impeller inside;
An underwater vortex suppression device fixed to the lower part of the suction bell mouth,
The underwater vortex suppression device is
At least two first underwater vortex suppression plates protruding downward from the suction bell mouth;
And at least one second underwater vortex suppression plate protruding downward from the suction bell mouth,
The at least two first underwater vortex suppression plates and the at least one second underwater vortex suppression plate extend from the central region of the suction bell mouth toward the radially outer side of the suction bell mouth,
Each of the at least two first underwater vortex suppression plates is upstream of the water flow direction with respect to a reference line passing through the axis of the suction bell mouth and parallel to the water flow direction in the suction water tank. It is inclined at an angle of 90 ° to 135 ° when viewed from the side,
The at least two first underwater vortex suppression plates project radially outward from a lower end of the suction bell mouth;
The pump is characterized in that the entire underwater vortex suppressing device is located inside an opening formed in a pump installation floor when viewed from the axial center of the suction bell mouth.   The pump according to claim 1, wherein the first underwater vortex suppressing plate has a horizontal slit extending in a horizontal direction from an outer end portion thereof. The underwater vortex suppressing device further includes a third underwater vortex suppressing plate extending from the first underwater vortex suppressing plate to the upstream side or the downstream side in the water flow direction,
3. The pump according to claim 1, wherein the third underwater vortex suppression plate is located radially outside of the suction bell mouth.   The pump according to claim 3, wherein the third underwater vortex suppressing plate has a horizontal slit extending in a horizontal direction from an outer end portion thereof.   The pump according to claim 3 or 4, wherein the third underwater vortex suppressing plate is connected to an outer end portion of the first underwater vortex suppressing plate.   The pump according to claim 1, wherein the first underwater vortex suppressing plate has at least one vertical slit extending upward from a lower end thereof.   The underwater vortex suppressing device further includes a third underwater vortex suppressing plate extending from the first underwater vortex suppressing plate to the upstream side or the downstream side in the water flow direction, and the third underwater vortex suppressing plate. The pump according to claim 6, wherein the pump is located radially outside of the suction bell mouth. The underwater vortex suppressing device further includes a vertical pipe extending in a vertical direction,
The pump according to claim 6, wherein the vertical pipe is fixed to an outer end portion of the first underwater vortex suppression plate. The underwater vortex suppressing device further includes two arc-shaped shielding plates,
The inner surfaces of the two shielding plates are curved along the outer peripheral surface of the lower end of the suction bell mouth,
2. The pump according to claim 1, wherein inner surfaces of the two shielding plates are fixed to outer end portions of the two first underwater vortex suppression plates, respectively. In the pump that pumps up the water in the suction tank,
The spindle,
An impeller fixed to the main shaft;
A pump casing having a suction bell mouth that opens downward, and containing the impeller inside;
An underwater vortex suppression device fixed to the lower part of the suction bell mouth,
The underwater vortex suppression device is
At least two first underwater vortex suppression plates protruding downward from the suction bell mouth;
At least one second underwater vortex suppression plate protruding downward from the suction bell mouth;
With multiple horizontal pipes,
The at least two first underwater vortex suppression plates and the at least one second underwater vortex suppression plate extend from the central region of the suction bell mouth toward the radially outer side of the suction bell mouth,
Each of the at least two first underwater vortex suppression plates is upstream of the water flow direction with respect to a reference line passing through the axis of the suction bell mouth and parallel to the water flow direction in the suction water tank. It is inclined at an angle of 90 ° to 135 ° when viewed from the side,
The plurality of horizontal pipes extend in the radial direction of the suction bell mouth, and are arranged along the vertical direction with a certain interval between each,
The plurality of horizontal pipes are fixed to outer end portions of the first underwater vortex suppression plate,
The pump is characterized in that the entire underwater vortex suppressing device is located inside an opening formed in a pump installation floor when viewed from the axial center of the suction bell mouth.   11. The pump according to claim 10, wherein ends of the plurality of horizontal pipes are bent toward an upstream side or a downstream side in the water flow direction. In the pump that pumps up the water in the suction tank,
The spindle,
An impeller fixed to the main shaft;
A pump casing having a suction bell mouth that opens downward, and containing the impeller inside;
An underwater vortex suppression device fixed to the lower part of the suction bell mouth,
The underwater vortex suppression device is
Two first underwater vortex suppression plates protruding downward from the suction bell mouth;
Two second underwater vortex suppression plates protruding downward from the suction bell mouth,
The two first underwater vortex suppression plates and the two second underwater vortex suppression plates extend from the inside of the suction bell mouth toward the outside of the suction bell mouth,
The two first underwater vortex suppression plates project outward from the lower end of the suction bell mouth,
Each of the two straight lines extending from the axis of the suction bell mouth to the intersection of the two first underwater vortex suppression plates and the lower end of the suction bell mouth passes through the axis of the suction bell mouth. When viewed from the upstream side of the water flow direction with respect to a reference line parallel to the water flow direction in the water tank, an angle of 90 ° to 135 ° is formed.
The pump is characterized in that the entire underwater vortex suppressing device is located inside an opening formed in a pump installation floor when viewed from the axial center of the suction bell mouth.   The pump according to claim 12, wherein the two first underwater vortex suppression plates are perpendicular to the reference line.

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