WO2023106299A1 - Vortex suppression member for pumps, pump, and pump facility - Google Patents

Vortex suppression member for pumps, pump, and pump facility Download PDF

Info

Publication number
WO2023106299A1
WO2023106299A1 PCT/JP2022/044957 JP2022044957W WO2023106299A1 WO 2023106299 A1 WO2023106299 A1 WO 2023106299A1 JP 2022044957 W JP2022044957 W JP 2022044957W WO 2023106299 A1 WO2023106299 A1 WO 2023106299A1
Authority
WO
WIPO (PCT)
Prior art keywords
pump
curved wall
vortex
suction port
bell mouth
Prior art date
Application number
PCT/JP2022/044957
Other languages
French (fr)
Japanese (ja)
Inventor
領太 繁原
▲キン▼ 辛
Original Assignee
株式会社クボタ
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社クボタ filed Critical 株式会社クボタ
Publication of WO2023106299A1 publication Critical patent/WO2023106299A1/en

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D13/00—Pumping installations or systems
    • F04D13/16—Pumping installations or systems with storage reservoirs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/40—Casings; Connections of working fluid
    • F04D29/52—Casings; Connections of working fluid for axial pumps
    • F04D29/54—Fluid-guiding means, e.g. diffusers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/66—Combating cavitation, whirls, noise, vibration or the like; Balancing

Definitions

  • the present invention relates to a vortex suppressing member for a pump that suppresses the generation of vortices at the suction port of the pump, a pump provided with the vortex suppressing member, and a pump facility including this pump in a suction tank.
  • water 201 such as rainwater flows into a water intake sump 202 of a pumping station, is sucked up by a vertical shaft pump 203, and is sent from the water intake sump 202 to a downstream treatment facility.
  • a standard sump 202 has a pair of side walls, a rear wall 205 and a bottom 206 .
  • a suction port 208 of the pump 203 is provided inside the suction tank 202 and positioned on the front side of the rear wall surface 205 .
  • the pump 203 By operating the pump 203, the water 201 in the water suction tank 202 flows into the pump 203 from the suction port 208, passes through the pump 203, and is sent to the downstream treatment facility. During operation of the pump 203 , an underwater vortex 211 and an air intake vortex 212 may be generated in the suction tank 202 .
  • the underwater vortex 211 is a vortex that is sucked into the suction port 208 in a state where the pressure of the vortex generated from the bottom surface 206 and side wall surfaces of the suction tank 202 is reduced below the vapor pressure.
  • the air intake vortex 212 is a vortex generated from the water surface toward the suction port 208 and entrains air on the water surface to be sucked into the suction port 208 .
  • the vortex suppressing member 220 includes a mounting flange 222 joined to the lower end of a downwardly opening bell mouth 221, and a curved wall 223 extending downward from the mounting flange 222 and having a cross section curved in an arc concentric with the bell mouth. and a downwardly extending flat baffle plate 224 provided between both ends of the curved wall 223 in the circumferential direction 227 .
  • the curved wall 223 and the baffle plate 224 form a hollow body 225 that is open in both vertical directions.
  • the flow F2 near the bottom surface 206 of the suction tank 202 approaches the pump 203 from the front upstream side 214 and flows into the suction port 208 .
  • the water 201 immediately before flowing into the suction port 208 collides with the baffle plate 224, thereby preventing the generation of swirl flow and effectively suppressing the generation of underwater vortices.
  • the curved wall 223 of the vortex suppressing member 220 acts as a resistance to the downward flow F1' that descends along the rear wall surface 205 from the back of the casing 226, so that the upstream side 214 of the casing 226 descends from near the surface of the water.
  • the flow F3 sucked into the suction port 208 increases, and the downward flow F1' descending along the rear wall surface 205 from behind the casing 226 weakens. Therefore, the generation of air intake vortices is also suppressed.
  • the vortex suppressing member 220 as described above is described, for example, in JP2019-157808A.
  • the flow rate during operation of the vertical shaft pump 203 is set to a predetermined flow rate.
  • the vertical shaft pump 203 is operated with a flow rate higher than a predetermined flow rate without changing the diameter of the vertical shaft pump 203, it becomes difficult to sufficiently suppress the occurrence of underwater vortices and air-sucking vortices. As a result, an underwater vortex or an air entrainment vortex may occur.
  • An object of the present invention is to provide a vortex suppressing member for a pump, a pump, and pump equipment that can sufficiently suppress the generation of underwater vortices and air-sucking vortices.
  • a vortex suppression member mounted in a downwardly opening bell mouth of a pump comprising: a curved wall extending downward from a portion of the peripheral edge of the suction port of the bell mouth in the circumferential direction and having an arcuate cross section; and a lower projecting member projecting inwardly of the curved wall from the lower end of the curved wall.
  • the vortex suppressing member is attached to the bell mouth, and the pump is operated with the curved wall of the vortex suppressing member facing the rear wall surface of the suction tank.
  • the curved wall acts as a resistance to the flow (flow near the surface of the water) that passes through the side of the pump from the front upstream side, descends along the rear wall surface from behind the pump, and is sucked into the suction port (flow near the water surface). becomes. Therefore, the amount of water sucked into the suction port from the rear wall surface side of the suction tank becomes smaller than the amount of water sucked into the suction port from the front upstream side of the suction tank.
  • the curved wall acts as a resistance to the flow that descends along the rear wall surface from behind the pump, so that the flow that descends from near the water surface on the upstream side of the pump and is sucked into the suction port increases. Downward flow from behind the pump along the rear wall weakens. Therefore, the generation of the air intake vortex is suppressed.
  • the distance that part of the water in the suction sump descends from the water surface along the rear wall behind the pump, passes through the inside of the curved wall, and is sucked into the suction port is the distance when the lower overhang member is not provided. is extra long by a distance corresponding to the overhang width of the lower overhang member.
  • This increases the resistance when water flows into the suction port from the rear wall side of the suction tank through the inside of the curved wall of the vortex suppressing member, further reducing the flow rate of water sucked into the suction port from the rear wall side. , the flow descending along the rear wall from behind the pump is further weakened. Therefore, the generation of air entrainment vortices is sufficiently suppressed.
  • the curved wall is provided with the partition wall that partitions the inside of the curved wall, It is preferable that a hollow body surrounded by curved walls and partition walls and open in both upper and lower directions is formed.
  • the bottom plate facing the lower part of the suction port is attached to the partition wall, and that the bottom plate is arranged on the extension of the axis of the bell mouth.
  • the upper end of the partition wall is lower than the upper end of the curved wall.
  • the flow rate that flows from the upstream side of the suction tank to the inside of the curved wall through the upper part of the partition wall increases.
  • the flow that descends from behind the pump along the rear wall surface of the suction sump is further weakened by the amount of the increase. Therefore, the generation of air entrainment vortices is sufficiently suppressed.
  • the pump of the present invention is a pump provided with the vortex suppressing member described above, and the vortex suppressing member is attached to the bell mouth.
  • the pump equipment of the present invention includes the above-described pump in a suction tank, the suction port of the bellmouth is provided in the suction tank and is located in front of the rear wall surface of the suction tank, and the vortex suppressing member is curved.
  • the wall faces the rear wall surface of the suction trough.
  • FIG. 2 is a cross-sectional view taken along the line XX in FIG. 1; 2 is an enlarged cross-sectional view of a joint portion between a bell mouth and a vortex suppressing member of the pump in FIG. 1; FIG. FIG. 2 is a view of the vortex suppressing member of the pump in FIG. 1 as viewed obliquely from above; FIG. 2 is a view of the vortex suppressing member of the pump in FIG. 1 as seen obliquely from below; FIG. 2 is a plan view of a vortex suppressor member of the pump in FIG. 1; FIG. 7 is a cross-sectional view taken along the line XX in FIG.
  • FIG. 6 is a bottom view of the vortex dampening member of the pump in Figure 6;
  • FIG. 8 is a view taken along line XX in FIG. 7;
  • FIG. 4 is a diagram showing a water flow in a suction sump and an approaching flow velocity distribution when the pump is in operation; It is the figure which looked at the vortex suppression member of the pump in the 2nd Embodiment of this invention from diagonally above.
  • FIG. 12 is an oblique bottom view of the vortex suppression member of the pump of FIG. 11;
  • Figure 12 is a cross-sectional view of a vortex suppressor member of the pump of Figure 11; It is the figure which looked at the vortex suppressing member of the pump in the 3rd Embodiment of this invention from the diagonally upper side.
  • FIG. 15 is a view of the vortex suppression member of the pump of FIG. 14 when viewed obliquely from below;
  • Figure 15 is a cross-sectional view of a vortex suppressor member of the pump of Figure 14; It is the figure which looked at the vortex suppression member of the pump in the 4th Embodiment of this invention from the diagonally upper side.
  • FIG. 18 is an oblique bottom view of the vortex suppression member of the pump of FIG. 17;
  • Figure 18 is a plan view of a vortex dampening member of the pump of Figure 17;
  • FIG. 20 is a cross-sectional view taken along the line XX in FIG.
  • Figure 18 is a bottom view of the vortex suppressor member of the pump of Figure 17; It is the figure which looked at the vortex suppression member of the pump in the 5th Embodiment of this invention from the diagonally downward direction.
  • a pump facility 1 installed at a pumping station includes a water intake tank 2 and water 3 such as rainwater that has flowed into the water intake tank 2 and pumps it up to the downstream side. and a pump 10 that feeds the treatment facility.
  • the suction tank 2 is of a standard flow rate open type, and has a pair of left and right side wall surfaces 5, a rear wall surface 7 and a bottom surface 8.
  • the water 3 flows into the pump 10 from the upstream side 9 of the pump 10 .
  • the pump 10 is a vertical shaft pump and has a pump body 11 and a vortex suppressing member 12 .
  • the pump body 11 has a vertically extending casing 14 , a rotatable main shaft 15 inserted through the casing 14 , an impeller 16 that rotates together with the main shaft 15 , and a rotary drive device 17 that rotates the main shaft 15 . ing.
  • the casing 14 includes a straight pumping pipe 19 , a pump case 20 connected to the lower end of the pumping pipe 19 , a bell mouth 21 connected to the lower end of the pump case 20 , and a discharge port connected to the upper end of the pumping pipe 19 .
  • an elbow 22 As shown in FIGS. 1 and 3, the bell mouth 21 has a suction port 23 and a flange 24 at its lower end.
  • the suction port 23 is provided inside the water suction tank 2 and positioned on the front side (upstream side) of the rear wall surface 7 .
  • the vortex suppression member 12 is detachably attached to the lower end of the bell mouth 21.
  • the vortex suppressing member 12 extends downward from a part of the periphery of the suction port 23 of the bell mouth 21, and has a curved wall 30 whose cross section is curved in an arc concentric with the suction port 23, and an upper end portion of the curved wall 30.
  • An annular mounting flange 31 (an example of a mounting member) provided in the curved wall 30 through two (plurality of) partition walls 32 and 33 that partition the inside of the curved wall 30 and the partition walls 32 and 33 and a lower projecting member 41 projecting from the lower end of the curved wall 30 toward the inside of the curved wall 30 .
  • the curved wall 30 faces the rear wall surface 7 of the suction tank 2 .
  • the mounting flange 31 is detachably joined to the flange 24 of the bell mouth 21 with a plurality of bolts 36 .
  • Both partition walls 32 and 33 are plate-like members arranged in parallel, of which the first partition wall 32 is provided between both ends of the curved wall 30 in the circumferential direction 37 . Thereby, a hollow body 38 surrounded by the curved wall 30 and the first partition wall 32 and open in both upper and lower directions is formed.
  • the second partition wall 33 is provided inside the hollow body 38 .
  • the upper ends 32a and 33a of the first and second partition walls 32 and 33 are lower than the upper end 30a of the curved wall 30, and the upper ends 32a and 33a of the first and second partition walls 32 and 33
  • the heights of these partition walls 32 and 33 are set so that the lower ends 32b and 33b are at the same height as the lower end 30b of the curved wall 30, respectively.
  • the bottom plate 34 is a rectangular flat plate attached between the lower ends 32b, 33b of the first and second partition walls 32, 33.
  • the bottom plate 34 faces below the suction port 23 of the bell mouth 21 and is arranged on an extension of the axial center 40 of the bell mouth 21 .
  • the lower projecting member 41 projects radially inward of the curved wall 30 .
  • the lower projecting member 41 is formed in a C shape when viewed from the axial direction (vertical direction) of the bell mouth 21 .
  • the bottom plate 34 is inside the contour of the suction port 23 of the bell mouth 21 when viewed from the axial direction of the bell mouth 21 .
  • the impeller 16 By operating the pump 10, the impeller 16 (see FIG. 1) rotates. Then, the water 3 in the suction tank 2 is sucked into the casing 14 through the suction port 23 of the bell mouth 21 and sent to the downstream processing facility through the discharge elbow 22 (see FIG. 1). At this time, as shown in FIG. 10, the curved wall 30 of the vortex suppressing member 12 acts as a resistance against the flows F1 and F1', so that the velocity V1 of the flow F1 of the water 3 near the surface of the water slows down, and from behind the casing 14 The speed of the descending flow F1' descending along the rear wall surface 7 decreases. This reduces the vorticity in the vicinity of the suction port 23 and suppresses the generation of underwater vortices.
  • the flow F2 near the bottom surface 8 of the suction tank 2 approaches the pump 10 from the front upstream side 9 and flows into the suction port 23 .
  • the water 3 immediately before flowing into the suction port 23 collides with at least one of the first and second partition walls 32 and 33, thereby preventing the generation of a swirling flow and further effectively generating an underwater vortex. suppressed by
  • the curved wall 30 of the vortex suppressing member 12 acts as a resistance to the downward flow F1', and as shown in FIG.
  • the downward flow F1' descending along the rear wall surface 7 from behind the casing 14 weakens. Therefore, the generation of air intake vortices is also suppressed.
  • the upper ends 32a, 33a of the first and second partition walls 32, 33 of the vortex suppressing member 12 are positioned lower than the upper end 30a of the curved wall 30.
  • the amount of flow that flows from the front upstream side 9 of the water suction sump 2 to the inside of the curved wall 30 through above the first or second partition walls 32 and 33 increases.
  • the downward flow F1' descending from behind the pump 10 along the rear wall surface 7 of the suction tank 2 is further weakened by the amount of the increase. This sufficiently suppresses the generation of air entrainment vortices.
  • the bottom plate 34 and the lower projecting member 41 are separated.
  • the bottom plate 34 and the lower projecting member 41 are integrally connected.
  • the lower projecting member 41 is formed in a sector shape when viewed from the axial direction (vertical direction) of the bell mouth 21 .
  • a fan-shaped region surrounded by the lower end 30 b of the curved wall 30 and the lower end 33 b of the second partition wall 33 is closed by the lower projecting member 41 .
  • the upper ends 32a, 33a of the first and second partition walls 32, 33 are lower than the upper end 30a of the curved wall 30, respectively, and the lower ends 32b, 33b of the first and second partition walls 32, 33 are lower than the upper end 30a. are at the same height as the lower end 30b of the curved wall 30, respectively.
  • Flow passages 42b and 42c are formed from below the curved wall 30 to above the curved wall 30 through between the curved wall 30 and the bottom plate 34.
  • the flow passage 42a shown in FIG. 7 of the first embodiment is closed by the lower projecting member 41. As shown in FIG. Therefore, after part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, it flows through the flow passages 42b and 42b as shown in FIGS. It is sucked into the suction port 23 of the bell mouth 21 through 42c.
  • the distance of the flow through the flow passages 42b and 42c until it is sucked into the suction port 23 is greater than that in the case where the lower projecting member 41 is not provided. It is extra long by a distance corresponding to the overhang width W of 41 .
  • the generation of underwater eddies is further suppressed.
  • the bottom plate 34 is provided at the same height as the lower projecting member 41, as shown in FIG.
  • the bottom plate 34 is provided at a position higher than the lower projecting member 41.
  • Upper ends 32a and 33a of the first and second partition walls 32 and 33 are approximately the same height as the upper end 30a of the curved wall 30, respectively.
  • the lower ends 32b, 33b of the first and second partition walls 32, 33 are higher than the lower end 30b of the curved wall 30, respectively.
  • the bottom plate 34 is provided between the lower ends 32b, 33b of the first and second partition walls 32, 33. As shown in FIG.
  • Flow passages 42a, 42b, 42c are formed from below the curved wall 30 to above the curved wall 30 through between the curved wall 30 and the bottom plate 34.
  • part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, and then passes through the flow passages 42a, 42b, 42c of the vortex suppressing member 12 to reach the bell mouth 21. is sucked into the suction port 23 of the At that time, as shown in FIG. 16, the distance of the flow through the flow passage 42a until it is sucked into the suction port 23 is greater than that of the lower projecting member 41 in the front-rear direction, compared to the case where the lower projecting member 41 is not provided. It is extra long by a distance corresponding to the overhang width W.
  • the lower ends 32b, 33b of the first and second partition walls 32, 33 are positioned higher than the lower end 30b of the curved wall 30.
  • the amount of flow from the front upstream side 9 of the water suction tank 2 to the inside of the curved wall 30 through the lower side of the first or second partition walls 32 and 33 increases, and the amount of water flowing into the water suction tank 2 from behind the pump 10 increases accordingly.
  • the descending flow F1' descending along the rear wall surface 7 of is further weakened. This sufficiently suppresses the generation of air entrainment vortices.
  • the upper ends 32a and 33a of the first and second partition walls 32 and 33 are separated from the upper end 30a of the curved wall 30.
  • the lower ends 32b and 33b of the first and second partition walls 32 and 33 are positioned higher than the lower end 30b of the curved wall 30.
  • the upper ends 32a, 33a of the first and second partition walls 32, 33 are positioned at the same height as the upper end 30a of the curved wall 30, and the lower ends of the first and second partition walls 32, 33 are positioned at the same height.
  • the portions 32b, 33b may be positioned at the same height as the lower end portion 30b of the curved wall 30.
  • the curved wall 30 is provided with one (single) partition wall 60 that partitions the inside of the curved wall 30 .
  • the bottom plate 34 is a substantially rectangular flat plate. Both short side edges 34 a of the bottom plate 34 are attached to the inside of the curved wall 30 , and one long side edge 34 b of the bottom plate 34 is attached to the lower end 60 b of the partition wall 60 .
  • the bottom plate 34 is provided at a position higher than the lower projecting member 41.
  • the upper end 60a of the partition wall 60 is approximately the same height as the upper end 30a of the curved wall 30.
  • a lower end portion 60 b of the partition wall 60 is higher than a lower end portion 30 b of the curved wall 30 .
  • a flow passage 42 is formed from below the curved wall 30 to above the curved wall 30 through between the curved wall 30 and the bottom plate 34 .
  • the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, passes through the flow passage 42, and is sucked into the suction port 23 of the bell mouth 21.
  • the distance of the flow until it reaches the end becomes longer by a distance corresponding to the width W of the lower projecting member 41 extending in the front-rear direction, compared to the case where the lower projecting member 41 is not provided.
  • This increases the resistance when the water 3 flows from the rear wall surface 7 side into the suction port 23 through the inside of the curved wall 30 (that is, the inside of the hollow body 38), and is drawn into the suction port 23 from the rear wall surface 7 side.
  • the downward flow F1' descending along the rear wall surface 7 from behind the pump 10 is further weakened. Therefore, the generation of air entrainment vortices is further suppressed.
  • the amount of water flowing from the front upstream side 9 of the suction tank 2 to the inside of the curved wall 30 through the bottom plate 34 and the partition wall 60 increases.
  • the downward flow F1' descending from behind the pump 10 along the rear wall surface 7 of the suction tank 2 is further weakened by this increase. This sufficiently suppresses the generation of air entrainment vortices.
  • the vortex suppression member 12 has the curved wall 30, the mounting flange 31, the partition walls 32 and 33, the bottom plate 34, and the lower projecting member 41. As shown in FIG. On the other hand, as shown in FIGS. 22 and 23, the vortex suppressing member 12 does not have the partition walls 32 and 33 and the bottom plate 34, and the curved wall 30, the mounting flange 31 and the lower projecting member 41 are separated. have.
  • the lower projecting member 41 is formed in a sector shape when viewed from the axial direction (vertical direction) of the bell mouth 21 and is provided over the entire area inside the lower end portion 30b of the curved wall 30 .
  • Such a lower projecting member 41 has an arcuate outer edge 41a and a linear outer edge 41b.
  • the outer edge 41 b of the lower projecting member 41 is located between both ends of the curved wall 30 in the circumferential direction 37 .
  • a part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, and then flows from the outside to the inside of the curved wall 30 into the suction port 23 of the bell mouth 21.
  • the distance of the flow from the outside to the inside of the curved wall 30 and being sucked into the suction port 23 is lower than that in the case where the lower projecting member 41 is not provided.
  • the distance corresponding to the overhang width W of the overhang member 41 is extra.
  • the vortex suppressing member 12 is detachably attached to the lower end of the bell mouth 21 using bolts 36, as shown in FIG.
  • the vortex suppressing member 12 may be integrally attached to the lower end portion of the bell mouth 21 by welding or the like.
  • the upper end of the curved wall 30 of the vortex suppressing member 12 may be welded to the lower end of the bell mouth 21 without providing the mounting flange 31 on the curved wall 30 of the vortex suppressing member 12 .
  • the bottom plate 34 is rectangular.
  • the bottom plate 34 may be circular, elliptical, polygonal other than square, or the like.
  • the bottom plate 34 is provided at the same position as the lower end portion 30b of the curved wall 30 or at a position above the lower end portion 30b. However, the bottom plate 34 may be provided at a position below the lower end portion 30b.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)

Abstract

A vortex suppression member 12 is to be fitted to a bell mouth of a pump. The vortex suppression member 12 comprises: a curved wall 30 that is curved so as to have a cross-section having a circular arc shape and that extends downward from a circumferential part at the circumferential edge of a suction port of the bell mouth; and a lower extending member 41 that extends inward of the curved wall 30 from a lower end part 30b of the curved wall 30.

Description

ポンプの渦抑制部材、ポンプ、およびポンプ設備Vortex suppressors for pumps, pumps and pump equipment
　本発明は、ポンプの吸込み口における渦の発生を抑制する、ポンプの渦抑制部材と、渦抑制部材を備えたポンプと、このポンプを吸水槽に備えたポンプ設備とに関する。 The present invention relates to a vortex suppressing member for a pump that suppresses the generation of vortices at the suction port of the pump, a pump provided with the vortex suppressing member, and a pump facility including this pump in a suction tank.
　図２４に示すように、例えば雨水等の水２０１は、ポンプ場の吸水槽２０２に流入し、立軸ポンプ２０３によって吸い上げられたうえで、吸水槽２０２から下流側の処理施設に送られる。標準的な吸水槽２０２は一対の側壁面と後壁面２０５と底面２０６とを有する。ポンプ２０３の吸込口２０８は、吸水槽２０２内に設けられて後壁面２０５の手前側に位置する。 As shown in FIG. 24, water 201 such as rainwater flows into a water intake sump 202 of a pumping station, is sucked up by a vertical shaft pump 203, and is sent from the water intake sump 202 to a downstream treatment facility. A standard sump 202 has a pair of side walls, a rear wall 205 and a bottom 206 . A suction port 208 of the pump 203 is provided inside the suction tank 202 and positioned on the front side of the rear wall surface 205 .
　ポンプ２０３を運転することにより、吸水槽２０２内の水２０１は、吸込口２０８からポンプ２０３内に流入し、ポンプ２０３内を通って下流側の処理施設に送られる。ポンプ２０３を運転しているとき、吸水槽２０２内に水中渦２１１と空気吸込渦２１２とが発生することがある。 By operating the pump 203, the water 201 in the water suction tank 202 flows into the pump 203 from the suction port 208, passes through the pump 203, and is sent to the downstream treatment facility. During operation of the pump 203 , an underwater vortex 211 and an air intake vortex 212 may be generated in the suction tank 202 .
　水中渦２１１は、吸水槽２０２の底面２０６や側壁面から発生した渦流の圧力が蒸気圧以下に低下した状態で吸込口２０８に吸い込まれる渦である。空気吸込渦２１２は、水面から吸込口２０８に向かって発生した渦流が水面上の空気を連行して吸込口２０８に吸い込まれる渦である。 The underwater vortex 211 is a vortex that is sucked into the suction port 208 in a state where the pressure of the vortex generated from the bottom surface 206 and side wall surfaces of the suction tank 202 is reduced below the vapor pressure. The air intake vortex 212 is a vortex generated from the water surface toward the suction port 208 and entrains air on the water surface to be sucked into the suction port 208 .
　このような水中渦２１１や空気吸込渦２１２が吸込口２０８からポンプ２０３内に吸い込まれると、ポンプ２０３の運転中に、激しい振動や大きな騒音が発生する虞がある。 If such underwater vortex 211 or air suction vortex 212 is sucked into the pump 203 through the suction port 208, there is a risk that intense vibration or loud noise will occur during operation of the pump 203.
　水中渦２１１や空気吸込渦２１２の発生を抑制するために、吸水槽２０２の後壁面２０５や底面２０６に渦流防止板（図示省略）を設置する一般的な技術がある。このような技術以外に、例えば図２５，図２６に示すように、立軸ポンプ２０３のベルマウス２２１に渦抑制部材２２０を取り付けることがある。 In order to suppress the generation of the underwater vortex 211 and the air-sucking vortex 212, there is a general technique of installing a vortex prevention plate (not shown) on the rear wall surface 205 and the bottom surface 206 of the suction tank 202. In addition to such a technique, for example, as shown in FIGS.
　渦抑制部材２２０は、下向きに開口したベルマウス２２１の下端部に接合される取付フランジ２２２と、取付フランジ２２２から下方に延び、横断面がベルマウスと同心状の円弧状に湾曲した湾曲壁２２３と、湾曲壁２２３の周方向２２７における両端部間に設けられた、下方へ延びる平板状のバッフル板２２４とを有している。湾曲壁２２３とバッフル板２２４とで上下両方向に開口する中空体２２５が形成されている。 The vortex suppressing member 220 includes a mounting flange 222 joined to the lower end of a downwardly opening bell mouth 221, and a curved wall 223 extending downward from the mounting flange 222 and having a cross section curved in an arc concentric with the bell mouth. and a downwardly extending flat baffle plate 224 provided between both ends of the curved wall 223 in the circumferential direction 227 . The curved wall 223 and the baffle plate 224 form a hollow body 225 that is open in both vertical directions.
　ポンプ２０３を運転している際、流れＦ１，Ｆ１´が発生する。流れＦ１，Ｆ１´は、水面付近の上流側からポンプ２０３の側方を通過し、ポンプ２０３の背後から吸水槽２０２の後壁面２０５に沿って下降した後、吸込口２０８に吸い込まれる。渦抑制部材２２０の湾曲壁２２３は、流れＦ１，Ｆ１´に対する抵抗となる。 When the pump 203 is running, flows F1 and F1' are generated. The flows F1 and F1' pass from the upstream side near the water surface to the side of the pump 203, descend from behind the pump 203 along the rear wall surface 205 of the suction tank 202, and then are sucked into the suction port 208. The curved wall 223 of the vortex suppression member 220 provides resistance to the flows F1, F1'.
　この抵抗のため、水面付近の水２０１の流れＦ１の速度Ｖ１が遅くなり、ポンプ２０３のケーシング２２６の背後から後壁面２０５に沿って下降する下降流Ｆ１´の速度が低下する。それにより、吸込口２０８付近の渦度が小さくなるため、水中渦の発生が抑制される。 Due to this resistance, the speed V1 of the flow F1 of the water 201 near the water surface slows down, and the speed of the downward flow F1' descending along the rear wall surface 205 from behind the casing 226 of the pump 203 decreases. This reduces the vorticity in the vicinity of the suction port 208, thereby suppressing the generation of underwater vortices.
　吸水槽２０２の底面２０６付近の流れＦ２は、手前上流側２１４からポンプ２０３に接近して吸込口２０８に流れ込む。この際、吸込口２０８に流れ込む直前の水２０１がバッフル板２２４にぶつかることにより、旋回流の発生が妨げられて、水中渦の発生が効果的に抑制される。 The flow F2 near the bottom surface 206 of the suction tank 202 approaches the pump 203 from the front upstream side 214 and flows into the suction port 208 . At this time, the water 201 immediately before flowing into the suction port 208 collides with the baffle plate 224, thereby preventing the generation of swirl flow and effectively suppressing the generation of underwater vortices.
　上記のように渦抑制部材２２０の湾曲壁２２３がケーシング２２６の背後から後壁面２０５に沿って下降する下降流Ｆ１´に対する抵抗となることで、ケーシング２２６の手前上流側２１４の水面付近から下降して吸込口２０８に吸い込まれる流れＦ３が増加し、また上記ケーシング２２６の背後から後壁面２０５に沿って下降する下降流Ｆ１´が弱まる。このため、空気吸込渦の発生も抑制される。 As described above, the curved wall 223 of the vortex suppressing member 220 acts as a resistance to the downward flow F1' that descends along the rear wall surface 205 from the back of the casing 226, so that the upstream side 214 of the casing 226 descends from near the surface of the water. As a result, the flow F3 sucked into the suction port 208 increases, and the downward flow F1' descending along the rear wall surface 205 from behind the casing 226 weakens. Therefore, the generation of air intake vortices is also suppressed.
　これらにより、運転中のポンプ１から激しい振動や大きな騒音が発生するのを防止することができる。 As a result, it is possible to prevent the pump 1 during operation from generating violent vibrations and loud noises.
　上記のような渦抑制部材２２０は、例えばＪＰ２０１９－１５７８０８Ａに記載されている。 The vortex suppressing member 220 as described above is described, for example, in JP2019-157808A.
　上記の公知の構成では、立軸ポンプ２０３の運転時の流量は、所定流量に定められている。しかし、例えば、立軸ポンプ２０３の径を変更することなく流量を所定流量より増やして運転した場合、水中渦や空気吸込渦の発生を十分に抑制することは難しくなる。その結果、水中渦や空気吸込渦が発生してしまう虞がある。 In the known configuration described above, the flow rate during operation of the vertical shaft pump 203 is set to a predetermined flow rate. However, for example, if the vertical shaft pump 203 is operated with a flow rate higher than a predetermined flow rate without changing the diameter of the vertical shaft pump 203, it becomes difficult to sufficiently suppress the occurrence of underwater vortices and air-sucking vortices. As a result, an underwater vortex or an air entrainment vortex may occur.
　本発明は、水中渦や空気吸込渦の発生を十分に抑制することができる、ポンプの渦抑制部材、ポンプ、およびポンプ設備を提供することを目的とする。 An object of the present invention is to provide a vortex suppressing member for a pump, a pump, and pump equipment that can sufficiently suppress the generation of underwater vortices and air-sucking vortices.
　上記目的を達成するために、本発明は、
　ポンプにおける下向きに開口したベルマウスに取付られる渦抑制部材であって、
　ベルマウスの吸込口の周縁部における周方向の一部から下方に延び横断面円弧状に湾曲した湾曲壁と、
　湾曲壁の下端部から湾曲壁の内側へ張り出した下部張り出し部材とを有している。 In order to achieve the above object, the present invention
A vortex suppression member mounted in a downwardly opening bell mouth of a pump, comprising:
a curved wall extending downward from a portion of the peripheral edge of the suction port of the bell mouth in the circumferential direction and having an arcuate cross section;
and a lower projecting member projecting inwardly of the curved wall from the lower end of the curved wall.
　これによると、渦抑制部材がベルマウスに取り付けられ、渦抑制部材の湾曲壁が吸水槽の後壁面に対向された状態で、ポンプが運転される。ポンプが運転されると、湾曲壁は、手前上流側からポンプの側方を通過し、ポンプの背後から後壁面に沿って下降した後、吸込口に吸い込まれる流れ（水面付近の流れ）に対する抵抗となる。このため、吸水槽の後壁面側から吸込口に吸い込まれる水量が吸水槽の手前上流側から吸込口に吸い込まれる水量よりも少なくなる。このように、湾曲壁が、ポンプの背後から後壁面に沿って下降する流れに対する抵抗となることで、ポンプの手前上流側の水面付近から下降して吸込口に吸い込まれる流れが増加して、上記ポンプの背後から後壁面に沿って下降する流れが弱まる。このため、空気吸込渦の発生が抑制される。 According to this, the vortex suppressing member is attached to the bell mouth, and the pump is operated with the curved wall of the vortex suppressing member facing the rear wall surface of the suction tank. When the pump is running, the curved wall acts as a resistance to the flow (flow near the surface of the water) that passes through the side of the pump from the front upstream side, descends along the rear wall surface from behind the pump, and is sucked into the suction port (flow near the water surface). becomes. Therefore, the amount of water sucked into the suction port from the rear wall surface side of the suction tank becomes smaller than the amount of water sucked into the suction port from the front upstream side of the suction tank. In this way, the curved wall acts as a resistance to the flow that descends along the rear wall surface from behind the pump, so that the flow that descends from near the water surface on the upstream side of the pump and is sucked into the suction port increases. Downward flow from behind the pump along the rear wall weakens. Therefore, the generation of the air intake vortex is suppressed.
　吸水槽の水の一部が水面からポンプの背後の後壁面に沿って下降した後、湾曲壁の内側を通って吸込口に吸い込まれるまでの流れの距離は、下部張り出し部材を設けていない場合と比べて、下部張り出し部材の張り出し幅に相当する距離だけ余分に長くなる。これにより、水が吸水槽の後壁面側から渦抑制部材の湾曲壁の内側を通って吸込口へ流入するときの抵抗が増加して、後壁面側から吸込口に吸い込まれる流量がさらに減少し、ポンプの背後から後壁面に沿って下降する流れがさらに弱まる。このため、空気吸込渦の発生が十分に抑制される。 The distance that part of the water in the suction sump descends from the water surface along the rear wall behind the pump, passes through the inside of the curved wall, and is sucked into the suction port is the distance when the lower overhang member is not provided. is extra long by a distance corresponding to the overhang width of the lower overhang member. This increases the resistance when water flows into the suction port from the rear wall side of the suction tank through the inside of the curved wall of the vortex suppressing member, further reducing the flow rate of water sucked into the suction port from the rear wall side. , the flow descending along the rear wall from behind the pump is further weakened. Therefore, the generation of air entrainment vortices is sufficiently suppressed.
　本発明の渦抑制部材によれば、湾曲壁の内側を仕切る仕切壁が湾曲壁に設けられて、
湾曲壁と仕切壁とで囲まれ且つ上下両方向が開口した中空体が形成されていることが好適である。 According to the vortex suppressing member of the present invention, the curved wall is provided with the partition wall that partitions the inside of the curved wall,
It is preferable that a hollow body surrounded by curved walls and partition walls and open in both upper and lower directions is formed.
　本発明の渦抑制部材によれば、吸込口の下方に対向する底板が仕切壁に取り付けられ、底板はベルマウスの軸心の延長線上に配置されていることが好適である。 According to the vortex suppressing member of the present invention, it is preferable that the bottom plate facing the lower part of the suction port is attached to the partition wall, and that the bottom plate is arranged on the extension of the axis of the bell mouth.
　水中渦はベルマウスの軸心の延長線付近に発生し易いので、底板をベルマウスの軸心の延長線上に配置することによって、水中渦の発生を十分に抑制することができる。 Since underwater vortices tend to occur near the extension of the axis of the bell mouth, the generation of underwater vortices can be sufficiently suppressed by arranging the bottom plate on the extension of the axis of the bell mouth.
　本発明の渦抑制部材は、仕切壁の上端部が湾曲壁の上端部よりも下位にあることが好適である。 In the vortex suppressing member of the present invention, it is preferable that the upper end of the partition wall is lower than the upper end of the curved wall.
　これによると、吸水槽の手前上流側から仕切壁の上方を通って湾曲壁の内側に流れ込む流量が増加する。その増加の分だけ、ポンプの背後から吸水槽の後壁面に沿って下降する流れがさらに弱まる。このため、空気吸込渦の発生が十分に抑制される。 According to this, the flow rate that flows from the upstream side of the suction tank to the inside of the curved wall through the upper part of the partition wall increases. The flow that descends from behind the pump along the rear wall surface of the suction sump is further weakened by the amount of the increase. Therefore, the generation of air entrainment vortices is sufficiently suppressed.
　本発明のポンプは、上記の渦抑制部材を備えたポンプであって、渦抑制部材がベルマウスに取り付けられている。 The pump of the present invention is a pump provided with the vortex suppressing member described above, and the vortex suppressing member is attached to the bell mouth.
　本発明のポンプ設備は、上記ポンプを吸水槽に備えたポンプ設備であって、ベルマウスの吸込口が吸水槽内に設けられて吸水槽の後壁面の手前側にあり、渦抑制部材の湾曲壁が吸水槽の後壁面に対向している。 The pump equipment of the present invention includes the above-described pump in a suction tank, the suction port of the bellmouth is provided in the suction tank and is located in front of the rear wall surface of the suction tank, and the vortex suppressing member is curved. The wall faces the rear wall surface of the suction trough.
　本発明によると、水中渦や空気吸込渦の発生を十分に抑制することができる。 According to the present invention, it is possible to sufficiently suppress the generation of underwater vortices and air entrainment vortices.
本発明の第１の実施の形態におけるポンプの側面図である。It is a side view of a pump in a 1st embodiment of the present invention. 図１におけるＸ－Ｘ断面図である。FIG. 2 is a cross-sectional view taken along the line XX in FIG. 1; 図１におけるポンプのベルマウスと渦抑制部材との接合部分の拡大断面図である。2 is an enlarged cross-sectional view of a joint portion between a bell mouth and a vortex suppressing member of the pump in FIG. 1; FIG. 図１におけるポンプの渦抑制部材を斜め上から見た図である。FIG. 2 is a view of the vortex suppressing member of the pump in FIG. 1 as viewed obliquely from above; 図１におけるポンプの渦抑制部材を斜め下から見た図である。FIG. 2 is a view of the vortex suppressing member of the pump in FIG. 1 as seen obliquely from below; 図１におけるポンプの渦抑制部材の平面図である。FIG. 2 is a plan view of a vortex suppressor member of the pump in FIG. 1; 図６におけるＸ－Ｘ断面図である。FIG. 7 is a cross-sectional view taken along the line XX in FIG. 6; 図６におけるポンプの渦抑制部材の底面図である。Figure 7 is a bottom view of the vortex dampening member of the pump in Figure 6; 図７におけるＸ－Ｘ矢視図である。FIG. 8 is a view taken along line XX in FIG. 7; ポンプを運転しているときの吸水槽における水流と近寄流速分布を示す図である。FIG. 4 is a diagram showing a water flow in a suction sump and an approaching flow velocity distribution when the pump is in operation; 本発明の第２の実施の形態におけるポンプの渦抑制部材を斜め上から見た図である。It is the figure which looked at the vortex suppression member of the pump in the 2nd Embodiment of this invention from diagonally above. 図１１のポンプの渦抑制部材を斜め下から見た図である。FIG. 12 is an oblique bottom view of the vortex suppression member of the pump of FIG. 11; 図１１のポンプの渦抑制部材の断面図である。Figure 12 is a cross-sectional view of a vortex suppressor member of the pump of Figure 11; 本発明の第３の実施の形態におけるポンプの渦抑制部材を斜め上から見た図である。It is the figure which looked at the vortex suppressing member of the pump in the 3rd Embodiment of this invention from the diagonally upper side. 図１４のポンプの渦抑制部材を斜め下から見たときの図である。FIG. 15 is a view of the vortex suppression member of the pump of FIG. 14 when viewed obliquely from below; 図１４のポンプの渦抑制部材の断面図である。Figure 15 is a cross-sectional view of a vortex suppressor member of the pump of Figure 14; 本発明の第４の実施の形態におけるポンプの渦抑制部材を斜め上から見た図である。It is the figure which looked at the vortex suppression member of the pump in the 4th Embodiment of this invention from the diagonally upper side. 図１７のポンプの渦抑制部材を斜め下から見た図である。FIG. 18 is an oblique bottom view of the vortex suppression member of the pump of FIG. 17; 図１７のポンプの渦抑制部材の平面図である。Figure 18 is a plan view of a vortex dampening member of the pump of Figure 17; 図１９におけるＸ－Ｘ断面図である。FIG. 20 is a cross-sectional view taken along the line XX in FIG. 19; 図１７のポンプの渦抑制部材の底面図である。Figure 18 is a bottom view of the vortex suppressor member of the pump of Figure 17; 本発明の第５の実施の形態におけるポンプの渦抑制部材を斜め下から見た図である。It is the figure which looked at the vortex suppression member of the pump in the 5th Embodiment of this invention from the diagonally downward direction. 図２２のポンプの渦抑制部材の断面図である。Figure 23 is a cross-sectional view of a vortex suppressor member of the pump of Figure 22; 公知のポンプと吸水槽の概略図である。1 is a schematic diagram of a known pump and sump; FIG. 公知の渦抑制部材を備えたポンプを運転しているときの吸水槽における水流と近寄流速分布とを示す図である。FIG. 5 is a diagram showing a water flow and an approaching flow velocity distribution in a suction sump when a pump having a known vortex suppressing member is in operation; 公知の渦抑制部材を斜め下から見た図である。1 is a view of a known vortex dampening member viewed obliquely from below; FIG.
　（第１の実施の形態）
　第１の実施の形態では、図１，図２に示すように、ポンプ場に設置されたポンプ設備１は、吸水槽２と、吸水槽２に流入した雨水等の水３を吸い上げて下流側の処理施設に送るポンプ１０とを有している。 (First embodiment)
In the first embodiment, as shown in FIGS. 1 and 2, a pump facility 1 installed at a pumping station includes a water intake tank 2 and water 3 such as rainwater that has flowed into the water intake tank 2 and pumps it up to the downstream side. and a pump 10 that feeds the treatment facility.
　吸水槽２は、標準流速オープン形であり、左右一対の側壁面５と後壁面７と底面８とを有している。水３は、ポンプ１０の手前上流側９からポンプ１０に流入する。 The suction tank 2 is of a standard flow rate open type, and has a pair of left and right side wall surfaces 5, a rear wall surface 7 and a bottom surface 8. The water 3 flows into the pump 10 from the upstream side 9 of the pump 10 .
　ポンプ１０は、立軸ポンプであり、ポンプ本体１１と渦抑制部材１２とを有している。 The pump 10 is a vertical shaft pump and has a pump body 11 and a vortex suppressing member 12 .
　ポンプ本体１１は、鉛直方向に延びるケーシング１４と、ケーシング１４内に挿通された回転自在な主軸１５と、主軸１５と共に回転する羽根車１６と、主軸１５を回転させる回転駆動装置１７とを有している。 The pump body 11 has a vertically extending casing 14 , a rotatable main shaft 15 inserted through the casing 14 , an impeller 16 that rotates together with the main shaft 15 , and a rotary drive device 17 that rotates the main shaft 15 . ing.
　ケーシング１４は、直管状の揚水管１９と、揚水管１９の下端に連結されたポンプケース２０と、ポンプケース２０の下端に連結されたベルマウス２１と、揚水管１９の上端に連結された吐出エルボ２２とを有している。図１，図３に示すように、ベルマウス２１は、下端に、吸込口２３とフランジ２４とを有している。吸込口２３は、吸水槽２内に設けられて、後壁面７の手前側（上流側）に位置する。 The casing 14 includes a straight pumping pipe 19 , a pump case 20 connected to the lower end of the pumping pipe 19 , a bell mouth 21 connected to the lower end of the pump case 20 , and a discharge port connected to the upper end of the pumping pipe 19 . an elbow 22; As shown in FIGS. 1 and 3, the bell mouth 21 has a suction port 23 and a flange 24 at its lower end. The suction port 23 is provided inside the water suction tank 2 and positioned on the front side (upstream side) of the rear wall surface 7 .
　図４～図９に示すように、渦抑制部材１２は、ベルマウス２１の下端部に着脱自在に取り付けられている。渦抑制部材１２は、ベルマウス２１の吸込口２３の周縁部の一部から下方に延び、横断面が吸込口２３と同心状の円弧状に湾曲した湾曲壁３０と、湾曲壁３０の上端部に設けられた円環状の取付フランジ３１（取付部材の一例）と、湾曲壁３０の内側を仕切る２枚（複数枚）の仕切壁３２，３３と、仕切壁３２，３３を介して湾曲壁３０に支持される底板３４と、湾曲壁３０の下端部から湾曲壁３０の内側へ張り出した下部張り出し部材４１とを有している。 As shown in FIGS. 4 to 9, the vortex suppression member 12 is detachably attached to the lower end of the bell mouth 21. As shown in FIGS. The vortex suppressing member 12 extends downward from a part of the periphery of the suction port 23 of the bell mouth 21, and has a curved wall 30 whose cross section is curved in an arc concentric with the suction port 23, and an upper end portion of the curved wall 30. An annular mounting flange 31 (an example of a mounting member) provided in the curved wall 30 through two (plurality of) partition walls 32 and 33 that partition the inside of the curved wall 30 and the partition walls 32 and 33 and a lower projecting member 41 projecting from the lower end of the curved wall 30 toward the inside of the curved wall 30 .
　図１，図２に示すように、湾曲壁３０は吸水槽２の後壁面７に対向している。図３に示すように、取付フランジ３１は、複数本のボルト３６によって、着脱自在にベルマウス２１のフランジ２４に接合されている。 As shown in FIGS. 1 and 2, the curved wall 30 faces the rear wall surface 7 of the suction tank 2 . As shown in FIG. 3 , the mounting flange 31 is detachably joined to the flange 24 of the bell mouth 21 with a plurality of bolts 36 .
　両仕切壁３２，３３はそれぞれ平行に配列された平板状の部材であり、このうち、第１仕切壁３２は湾曲壁３０の周方向３７における両端部間に設けられている。これにより、湾曲壁３０と第１仕切壁３２とで囲まれ且つ上下両方向が開口した中空体３８が形成されている。第２仕切壁３３は中空体３８の内側に設けられている。 Both partition walls 32 and 33 are plate-like members arranged in parallel, of which the first partition wall 32 is provided between both ends of the curved wall 30 in the circumferential direction 37 . Thereby, a hollow body 38 surrounded by the curved wall 30 and the first partition wall 32 and open in both upper and lower directions is formed. The second partition wall 33 is provided inside the hollow body 38 .
　図７に示すように、第１および第２仕切壁３２，３３の上端部３２ａ，３３ａがそれぞれ湾曲壁３０の上端部３０ａよりも下位になるとともに、第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂがそれぞれ湾曲壁３０の下端部３０ｂと同じ高さになるように、これら仕切壁３２，３３の高さが設定されている。 As shown in FIG. 7, the upper ends 32a and 33a of the first and second partition walls 32 and 33 are lower than the upper end 30a of the curved wall 30, and the upper ends 32a and 33a of the first and second partition walls 32 and 33 The heights of these partition walls 32 and 33 are set so that the lower ends 32b and 33b are at the same height as the lower end 30b of the curved wall 30, respectively.
　底板３４は、第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂ間に取り付けられた四角形状の平板である。底板３４は、ベルマウス２１の吸込口２３の下方に対向し、ベルマウス２１の軸心４０の延長線上に配置されている。 The bottom plate 34 is a rectangular flat plate attached between the lower ends 32b, 33b of the first and second partition walls 32, 33. The bottom plate 34 faces below the suction port 23 of the bell mouth 21 and is arranged on an extension of the axial center 40 of the bell mouth 21 .
　図６，図８に示すように、下部張り出し部材４１は、湾曲壁３０の径方向における内側へ張り出している。下部張り出し部材４１は、ベルマウス２１の軸心方向（上下方向）から見て、Ｃ字形状に形成されている。 As shown in FIGS. 6 and 8, the lower projecting member 41 projects radially inward of the curved wall 30 . The lower projecting member 41 is formed in a C shape when viewed from the axial direction (vertical direction) of the bell mouth 21 .
　底板３４は、ベルマウス２１の軸心方向から見て、ベルマウス２１の吸込口２３の輪郭よりも内側にある。 The bottom plate 34 is inside the contour of the suction port 23 of the bell mouth 21 when viewed from the axial direction of the bell mouth 21 .
　これらによって、湾曲壁３０よりも下方から湾曲壁３０と底板３４との間を通って湾曲壁３０よりも上方へ抜ける流通路４２ａ，４２ｂ，４２ｃが形成されている。 These form flow passages 42 a , 42 b , 42 c that pass between the curved wall 30 and the bottom plate 34 from below the curved wall 30 and exit above the curved wall 30 .
　以下、上記構成にもとづく機能を説明する。 The functions based on the above configuration will be explained below.
　ポンプ１０を運転することにより、羽根車１６（図１参照）が回転する。すると、吸水槽２内の水３が、ベルマウス２１の吸込口２３からケーシング１４内に吸い込まれ、吐出エルボ２２（図１参照）を通って下流側の処理施設に送られる。この際、図１０に示すように、渦抑制部材１２の湾曲壁３０は流れＦ１，Ｆ１´に対する抵抗となるため、水面付近の水３の流れＦ１の速度Ｖ１が遅くなり、ケーシング１４の背後から後壁面７に沿って下降する下降流Ｆ１´の速度が低下する。これにより、吸込口２３付近の渦度が小さくなり、水中渦の発生が抑制される。 By operating the pump 10, the impeller 16 (see FIG. 1) rotates. Then, the water 3 in the suction tank 2 is sucked into the casing 14 through the suction port 23 of the bell mouth 21 and sent to the downstream processing facility through the discharge elbow 22 (see FIG. 1). At this time, as shown in FIG. 10, the curved wall 30 of the vortex suppressing member 12 acts as a resistance against the flows F1 and F1', so that the velocity V1 of the flow F1 of the water 3 near the surface of the water slows down, and from behind the casing 14 The speed of the descending flow F1' descending along the rear wall surface 7 decreases. This reduces the vorticity in the vicinity of the suction port 23 and suppresses the generation of underwater vortices.
　吸水槽２の底面８付近の流れＦ２は、手前上流側９からポンプ１０に接近して吸込口２３に流れ込む。この際、吸込口２３に流れ込む直前の水３が第１および第２仕切壁３２，３３の少なくともいずれかにぶつかることにより、旋回流の発生が妨げられて、水中渦の発生がより一層効果的に抑制される。 The flow F2 near the bottom surface 8 of the suction tank 2 approaches the pump 10 from the front upstream side 9 and flows into the suction port 23 . At this time, the water 3 immediately before flowing into the suction port 23 collides with at least one of the first and second partition walls 32 and 33, thereby preventing the generation of a swirling flow and further effectively generating an underwater vortex. suppressed by
　水中渦はベルマウス２１の軸心４０の延長線付近に発生し易い。このため、底板３４をベルマウス２１の軸心４０の延長線上に配置することによって、水中渦の発生を十分に抑制することができる。 An underwater vortex is likely to occur near the extension line of the axis 40 of the bell mouth 21 . Therefore, by arranging the bottom plate 34 on the extension of the axis 40 of the bell mouth 21, it is possible to sufficiently suppress the generation of underwater vortices.
　上述したように渦抑制部材１２の湾曲壁３０が下降流Ｆ１´に対する抵抗となることで、図１０に示すように、ケーシング１４の手前上流側９の水面付近から下降して吸込口２３に吸い込まれる流れＦ３が増加し、上記ケーシング１４の背後から後壁面７に沿って下降する下降流Ｆ１´が弱まる。このため、空気吸込渦の発生も抑制される。 As described above, the curved wall 30 of the vortex suppressing member 12 acts as a resistance to the downward flow F1', and as shown in FIG. The downward flow F1' descending along the rear wall surface 7 from behind the casing 14 weakens. Therefore, the generation of air intake vortices is also suppressed.
　吸水槽２の水３の一部は、水面からポンプ１０の背後の後壁面７に沿って下降した後、渦抑制部材１２の流通路４２ａ，４２ｂ，４２ｃを通ってベルマウス２１の吸込口２３に吸い込まれる。この際、図７に示すように、流通路４２ａを通って吸込口２３に吸い込まれるまでの流れの距離は、下部張り出し部材４１を設けていない場合と比べて、湾曲壁３０の径方向における下部張り出し部材４１の張り出し幅Ｗに相当する距離だけ余分に長くなる。 After part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, it passes through the flow passages 42a, 42b, and 42c of the vortex suppressing member 12 to the suction port 23 of the bell mouth 21. sucked into At this time, as shown in FIG. 7, the distance of the flow through the flow passage 42a until it is sucked into the suction port 23 is greater than that in the case where the lower projecting member 41 is not provided. The distance corresponding to the overhang width W of the overhang member 41 is extra.
　これにより、水３が後壁面７側から湾曲壁３０の内側（すなわち中空体３８の内側）を通って吸込口２３へ流入するときの抵抗が増加する。その結果、後壁面７側から吸込口２３に吸い込まれる流量がさらに減少し、ポンプ１０の背後から後壁面７に沿って下降する下降流Ｆ１´がさらに弱まるため、空気吸込渦の発生がより一層抑制される。 This increases the resistance when the water 3 flows from the rear wall surface 7 side into the suction port 23 through the inside of the curved wall 30 (that is, the inside of the hollow body 38). As a result, the flow rate sucked into the suction port 23 from the rear wall surface 7 side is further reduced, and the downward flow F1' descending along the rear wall surface 7 from behind the pump 10 is further weakened, so that the air suction vortex is further generated. Suppressed.
　図７に示すように、渦抑制部材１２の第１および第２仕切壁３２，３３の上端部３２ａ，３３ａを湾曲壁３０の上端部３０ａよりも下位にしている。このため、吸水槽２の手前上流側９から第１又は第２仕切壁３２，３３の上方を通って湾曲壁３０の内側に流れ込む流量が増加する。その増加の分だけ、ポンプ１０の背後から吸水槽２の後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。これにより、空気吸込渦の発生が十分に抑制される。 As shown in FIG. 7, the upper ends 32a, 33a of the first and second partition walls 32, 33 of the vortex suppressing member 12 are positioned lower than the upper end 30a of the curved wall 30. As shown in FIG. Therefore, the amount of flow that flows from the front upstream side 9 of the water suction sump 2 to the inside of the curved wall 30 through above the first or second partition walls 32 and 33 increases. The downward flow F1' descending from behind the pump 10 along the rear wall surface 7 of the suction tank 2 is further weakened by the amount of the increase. This sufficiently suppresses the generation of air entrainment vortices.
　吸水槽２の水３の一部は、渦抑制部材１２の湾曲壁３０の下方から流通路４２ａ，４２ｂ，４２ｃを通ってポンプ１０の吸込口２３に流入する際、湾曲壁３０と底板３４との間を下から上へ通過する。これにより、ポンプ１０の吸込口２３の下方を渦抑制部材１２の底板３４で覆い過ぎて圧力損失が過大になる（すなわちポンプ効率が低下する）のを防ぐことができる。或いは、渦抑制部材１２の手前上流側９の局所の流速が上がり過ぎて別の箇所に渦が発生するのを防ぐことができる。 When part of the water 3 in the suction tank 2 flows from below the curved wall 30 of the vortex suppressing member 12 through the flow passages 42a, 42b, and 42c into the suction port 23 of the pump 10, the curved wall 30 and the bottom plate 34 pass from bottom to top between As a result, it is possible to prevent the bottom plate 34 of the vortex suppressing member 12 from covering the lower part of the suction port 23 of the pump 10 too much, thereby preventing excessive pressure loss (that is, reduction in pump efficiency). Alternatively, it is possible to prevent the occurrence of vortices at other locations due to excessive local flow velocity on the upstream side 9 of the vortex suppressing member 12 .
　これにより、例えばポンプ１０の径を変更せずに流量を所定流量より増やして運転した場合であっても、水中渦や空気吸込渦の発生を十分に抑制することができる。その結果、運転中のポンプ１０から激しい振動や大きな騒音が発生するのを防止することができる。 As a result, for example, even when the pump 10 is operated with a flow rate greater than a predetermined flow rate without changing the diameter of the pump 10, it is possible to sufficiently suppress the occurrence of underwater vortices and air entrainment vortices. As a result, it is possible to prevent the pump 10 from generating violent vibrations and loud noises during operation.
　（第２の実施の形態）
　先述した第１の実施の形態では、図７，図８に示すように、底板３４と下部張り出し部材４１とは分離している。これに対し、第２の実施の形態では、図１１～図１３に示すように、底板３４と下部張り出し部材４１とは一体に繋がっている。下部張り出し部材４１は、ベルマウス２１の軸心方向（上下方向）から見て、扇形状に形成されている。湾曲壁３０の下端部３０ｂと第２仕切壁３３の下端部３３ｂとで囲まれた扇形状の領域は、下部張り出し部材４１によって閉鎖されている。 (Second embodiment)
In the above-described first embodiment, as shown in FIGS. 7 and 8, the bottom plate 34 and the lower projecting member 41 are separated. On the other hand, in the second embodiment, as shown in FIGS. 11 to 13, the bottom plate 34 and the lower projecting member 41 are integrally connected. The lower projecting member 41 is formed in a sector shape when viewed from the axial direction (vertical direction) of the bell mouth 21 . A fan-shaped region surrounded by the lower end 30 b of the curved wall 30 and the lower end 33 b of the second partition wall 33 is closed by the lower projecting member 41 .
　第１および第２仕切壁３２，３３の上端部３２ａ，３３ａがそれぞれ湾曲壁３０の上端部３０ａよりも下位になっているとともに、第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂがそれぞれ湾曲壁３０の下端部３０ｂと同じ高さになっている。 The upper ends 32a, 33a of the first and second partition walls 32, 33 are lower than the upper end 30a of the curved wall 30, respectively, and the lower ends 32b, 33b of the first and second partition walls 32, 33 are lower than the upper end 30a. are at the same height as the lower end 30b of the curved wall 30, respectively.
　湾曲壁３０の下方から湾曲壁３０と底板３４との間を通って湾曲壁３０の上方へ抜ける流通路４２ｂ，４２ｃが形成されている。 Flow passages 42b and 42c are formed from below the curved wall 30 to above the curved wall 30 through between the curved wall 30 and the bottom plate 34.
　これによると、上記第１の実施の形態の図７で示した流通路４２ａは下部張り出し部材４１によって閉鎖されている。このため、吸水槽２の水３の一部は、水面からポンプ１０の背後の後壁面７に沿って下降した後、流通路４２ａではなく、図１１～図１３に示すように流通路４２ｂ，４２ｃを通ってベルマウス２１の吸込口２３に吸い込まれる。 According to this, the flow passage 42a shown in FIG. 7 of the first embodiment is closed by the lower projecting member 41. As shown in FIG. Therefore, after part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, it flows through the flow passages 42b and 42b as shown in FIGS. It is sucked into the suction port 23 of the bell mouth 21 through 42c.
　この際、図１３に示すように、流通路４２ｂ，４２ｃを通って吸込口２３に吸い込まれるまでの流れの距離は、下部張り出し部材４１を設けていない場合と比べて、前後方向における下部張り出し部材４１の張り出し幅Ｗに相当する距離だけ余分に長くなる。 At this time, as shown in FIG. 13, the distance of the flow through the flow passages 42b and 42c until it is sucked into the suction port 23 is greater than that in the case where the lower projecting member 41 is not provided. It is extra long by a distance corresponding to the overhang width W of 41 .
　これにより、水３が後壁面７側から湾曲壁３０の内側（すなわち中空体３８の内側）を通って吸込口２３へ流入するときの抵抗が増加し、後壁面７側から吸込口２３に吸い込まれる流量がさらに減少し、ポンプ１０の背後から後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。このため、空気吸込渦の発生がより一層抑制される。 This increases the resistance when the water 3 flows from the rear wall surface 7 side into the suction port 23 through the inside of the curved wall 30 (that is, the inside of the hollow body 38), and is drawn into the suction port 23 from the rear wall surface 7 side. The flow rate of the pump 10 is further reduced, and the downward flow F1' descending along the rear wall surface 7 from behind the pump 10 is further weakened. Therefore, the generation of air entrainment vortices is further suppressed.
　先述した第１の実施の形態と同様に、水中渦の発生もより一層抑制される。 As in the first embodiment described above, the generation of underwater eddies is further suppressed.
　（第３の実施の形態）
　先述した第２の実施の形態では、図１３に示すように、底板３４は下部張り出し部材４１と同じ高さに設けられている。これに対し第３の実施の形態では、図１４～図１６に示すように、底板３４は下部張り出し部材４１よりも高い位置に設けられている。第１および第２仕切壁３２，３３の上端部３２ａ，３３ａはそれぞれ湾曲壁３０の上端部３０ａとほぼ同じ高さになっている。第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂがそれぞれ湾曲壁３０の下端部３０ｂよりも上位になっている。底板３４は、第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂどうしの間に設けられている。 (Third Embodiment)
In the above-described second embodiment, the bottom plate 34 is provided at the same height as the lower projecting member 41, as shown in FIG. On the other hand, in the third embodiment, as shown in FIGS. 14 to 16, the bottom plate 34 is provided at a position higher than the lower projecting member 41. As shown in FIGS. Upper ends 32a and 33a of the first and second partition walls 32 and 33 are approximately the same height as the upper end 30a of the curved wall 30, respectively. The lower ends 32b, 33b of the first and second partition walls 32, 33 are higher than the lower end 30b of the curved wall 30, respectively. The bottom plate 34 is provided between the lower ends 32b, 33b of the first and second partition walls 32, 33. As shown in FIG.
　湾曲壁３０の下方から湾曲壁３０と底板３４との間を通って湾曲壁３０の上方へ抜ける流通路４２ａ，４２ｂ，４２ｃが形成されている。 Flow passages 42a, 42b, 42c are formed from below the curved wall 30 to above the curved wall 30 through between the curved wall 30 and the bottom plate 34.
　これによると、吸水槽２の水３の一部は、水面からポンプ１０の背後の後壁面７に沿って下降した後、渦抑制部材１２の流通路４２ａ，４２ｂ，４２ｃを通ってベルマウス２１の吸込口２３に吸い込まれる。その際、図１６に示すように、流通路４２ａを通って吸込口２３に吸い込まれるまでの流れの距離は、下部張り出し部材４１を設けていない場合と比べて、前後方向における下部張り出し部材４１の張り出し幅Ｗに相当する距離だけ余分に長くなる。これにより、水３が後壁面７側から湾曲壁３０の内側（すなわち中空体３８の内側）を通って吸込口２３へ流入するときの抵抗が増加する。このため、後壁面７側から吸込口２３に吸い込まれる流量がさらに減少し、ポンプ１０の背後から後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。その結果、空気吸込渦の発生がより一層抑制される。 According to this, part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, and then passes through the flow passages 42a, 42b, 42c of the vortex suppressing member 12 to reach the bell mouth 21. is sucked into the suction port 23 of the At that time, as shown in FIG. 16, the distance of the flow through the flow passage 42a until it is sucked into the suction port 23 is greater than that of the lower projecting member 41 in the front-rear direction, compared to the case where the lower projecting member 41 is not provided. It is extra long by a distance corresponding to the overhang width W. This increases the resistance when the water 3 flows from the rear wall surface 7 side into the suction port 23 through the inside of the curved wall 30 (that is, the inside of the hollow body 38). As a result, the flow rate sucked into the suction port 23 from the rear wall surface 7 side is further reduced, and the downward flow F1' descending along the rear wall surface 7 from behind the pump 10 is further weakened. As a result, the generation of air entrainment vortices is further suppressed.
　第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂを湾曲壁３０の下端部３０ｂよりも上位にしている。このため、吸水槽２の手前上流側９から第１又は第２仕切壁３２，３３の下方を通って湾曲壁３０の内側に流れ込む流量が増加し、その分、ポンプ１０の背後から吸水槽２の後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。これにより、空気吸込渦の発生が十分に抑制される。 The lower ends 32b, 33b of the first and second partition walls 32, 33 are positioned higher than the lower end 30b of the curved wall 30. As a result, the amount of flow from the front upstream side 9 of the water suction tank 2 to the inside of the curved wall 30 through the lower side of the first or second partition walls 32 and 33 increases, and the amount of water flowing into the water suction tank 2 from behind the pump 10 increases accordingly. The descending flow F1' descending along the rear wall surface 7 of is further weakened. This sufficiently suppresses the generation of air entrainment vortices.
　上記第１～第３の実施の形態では、図７，図１３，図１６に示すように、第１および第２仕切壁３２，３３の上端部３２ａ，３３ａが湾曲壁３０の上端部３０ａよりも下位に位置するか、或いは、第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂが湾曲壁３０の下端部３０ｂよりも上位に位置している。これらに代えて、第１および第２仕切壁３２，３３の上端部３２ａ，３３ａが湾曲壁３０の上端部３０ａと同じ高さに位置するとともに、第１および第２仕切壁３２，３３の下端部３２ｂ，３３ｂが湾曲壁３０の下端部３０ｂと同じ高さに位置してもよい。 In the first to third embodiments described above, as shown in FIGS. 7, 13 and 16, the upper ends 32a and 33a of the first and second partition walls 32 and 33 are separated from the upper end 30a of the curved wall 30. As shown in FIGS. or the lower ends 32b and 33b of the first and second partition walls 32 and 33 are positioned higher than the lower end 30b of the curved wall 30. As shown in FIG. Instead of these, the upper ends 32a, 33a of the first and second partition walls 32, 33 are positioned at the same height as the upper end 30a of the curved wall 30, and the lower ends of the first and second partition walls 32, 33 are positioned at the same height. The portions 32b, 33b may be positioned at the same height as the lower end portion 30b of the curved wall 30.
　（第４の実施の形態）
　図１７～図２１に示すように、湾曲壁３０の内側を仕切る１枚（単数枚）の仕切壁６０が湾曲壁３０に設けられている。底板３４は略長方形の平板である。底板３４の両短辺縁３４ａが湾曲壁３０の内側に取り付けられており、底板３４の片方の長辺縁３４ｂが仕切壁６０の下端部６０ｂに取り付けられている。 (Fourth embodiment)
As shown in FIGS. 17 to 21, the curved wall 30 is provided with one (single) partition wall 60 that partitions the inside of the curved wall 30 . The bottom plate 34 is a substantially rectangular flat plate. Both short side edges 34 a of the bottom plate 34 are attached to the inside of the curved wall 30 , and one long side edge 34 b of the bottom plate 34 is attached to the lower end 60 b of the partition wall 60 .
　図２０に示すように、底板３４は下部張り出し部材４１よりも高い位置に設けられている。仕切壁６０の上端部６０ａは、湾曲壁３０の上端部３０ａとほぼ同じ高さになっている。仕切壁６０の下端部６０ｂは、湾曲壁３０の下端部３０ｂよりも上位になっている。これにより、湾曲壁３０と仕切壁６０とで囲まれ且つ上下両方向が開口した中空体３８が形成されている。 As shown in FIG. 20, the bottom plate 34 is provided at a position higher than the lower projecting member 41. As shown in FIG. The upper end 60a of the partition wall 60 is approximately the same height as the upper end 30a of the curved wall 30. As shown in FIG. A lower end portion 60 b of the partition wall 60 is higher than a lower end portion 30 b of the curved wall 30 . Thereby, a hollow body 38 surrounded by the curved wall 30 and the partition wall 60 and open in both upper and lower directions is formed.
　湾曲壁３０の下方から湾曲壁３０と底板３４との間を通って湾曲壁３０の上方へ抜ける流通路４２が形成されている。 A flow passage 42 is formed from below the curved wall 30 to above the curved wall 30 through between the curved wall 30 and the bottom plate 34 .
　これによると、図２０に示すように、吸水槽２の水３が水面からポンプ１０の背後の後壁面７に沿って下降した後、流通路４２を通ってベルマウス２１の吸込口２３に吸い込まれるまでの流れの距離は、下部張り出し部材４１を設けていない場合と比べて、前後方向における下部張り出し部材４１の張り出し幅Ｗに相当する距離だけ余分に長くなる。これにより、水３が後壁面７側から湾曲壁３０の内側（すなわち中空体３８の内側）を通って吸込口２３へ流入するときの抵抗が増加し、後壁面７側から吸込口２３に吸い込まれる流量がさらに減少して、ポンプ１０の背後から後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。このため、空気吸込渦の発生がより一層抑制される。 According to this, as shown in FIG. 20, the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, passes through the flow passage 42, and is sucked into the suction port 23 of the bell mouth 21. The distance of the flow until it reaches the end becomes longer by a distance corresponding to the width W of the lower projecting member 41 extending in the front-rear direction, compared to the case where the lower projecting member 41 is not provided. This increases the resistance when the water 3 flows from the rear wall surface 7 side into the suction port 23 through the inside of the curved wall 30 (that is, the inside of the hollow body 38), and is drawn into the suction port 23 from the rear wall surface 7 side. As a result, the downward flow F1' descending along the rear wall surface 7 from behind the pump 10 is further weakened. Therefore, the generation of air entrainment vortices is further suppressed.
　吸水槽２の手前上流側９から底板３４の下方および仕切壁６０の下方を通って湾曲壁３０の内側に流れ込む流量が増加する。この増加の分だけ、ポンプ１０の背後から吸水槽２の後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。これにより、空気吸込渦の発生が十分に抑制される。 The amount of water flowing from the front upstream side 9 of the suction tank 2 to the inside of the curved wall 30 through the bottom plate 34 and the partition wall 60 increases. The downward flow F1' descending from behind the pump 10 along the rear wall surface 7 of the suction tank 2 is further weakened by this increase. This sufficiently suppresses the generation of air entrainment vortices.
　（第５の実施の形態）
　先述した第１の実施の形態では、渦抑制部材１２は湾曲壁３０と取付フランジ３１と仕切壁３２，３３と底板３４と下部張り出し部材４１とを有している。これに対し、図２２，図２３に示すように、渦抑制部材１２は、仕切壁３２，３３と底板３４とを有しておらず、湾曲壁３０と取付フランジ３１と下部張り出し部材４１とを有している。 (Fifth embodiment)
In the first embodiment described above, the vortex suppression member 12 has the curved wall 30, the mounting flange 31, the partition walls 32 and 33, the bottom plate 34, and the lower projecting member 41. As shown in FIG. On the other hand, as shown in FIGS. 22 and 23, the vortex suppressing member 12 does not have the partition walls 32 and 33 and the bottom plate 34, and the curved wall 30, the mounting flange 31 and the lower projecting member 41 are separated. have.
　下部張り出し部材４１は、ベルマウス２１の軸心方向（上下方向）から見て扇形状に形成されていて、湾曲壁３０の下端部３０ｂの内側の全領域にわたって設けられている。このような下部張り出し部材４１は、円弧状の外周縁４１ａと直線状の外縁４１ｂとを有している。下部張り出し部材４１の外縁４１ｂは湾曲壁３０の周方向３７における両端部間に位置している。 The lower projecting member 41 is formed in a sector shape when viewed from the axial direction (vertical direction) of the bell mouth 21 and is provided over the entire area inside the lower end portion 30b of the curved wall 30 . Such a lower projecting member 41 has an arcuate outer edge 41a and a linear outer edge 41b. The outer edge 41 b of the lower projecting member 41 is located between both ends of the curved wall 30 in the circumferential direction 37 .
　吸水槽２の水３の一部は、水面からポンプ１０の背後の後壁面７に沿って下降した後、湾曲壁３０の外側から内側を通ってベルマウス２１の吸込口２３へ流入する。この際、図２３に示すように、湾曲壁３０の外側から内側を通って吸込口２３に吸い込まれるまでの流れの距離は、下部張り出し部材４１を設けていない場合と比べて、前後方向における下部張り出し部材４１の張り出し幅Ｗに相当する距離だけ余分に長くなる。 A part of the water 3 in the suction tank 2 descends from the water surface along the rear wall surface 7 behind the pump 10, and then flows from the outside to the inside of the curved wall 30 into the suction port 23 of the bell mouth 21. At this time, as shown in FIG. 23, the distance of the flow from the outside to the inside of the curved wall 30 and being sucked into the suction port 23 is lower than that in the case where the lower projecting member 41 is not provided. The distance corresponding to the overhang width W of the overhang member 41 is extra.
　これにより、水３が後壁面７側から湾曲壁３０の内側を通って吸込口２３へ流入するときの抵抗が増加する。それにより、後壁面７側から吸込口２３に吸い込まれる流量がさらに減少し、ポンプ１０の背後から後壁面７に沿って下降する下降流Ｆ１´がさらに弱まる。このため、空気吸込渦の発生がより一層抑制される。 This increases the resistance when the water 3 flows from the rear wall surface 7 side through the inside of the curved wall 30 into the suction port 23 . As a result, the flow rate sucked into the suction port 23 from the rear wall surface 7 side is further reduced, and the downward flow F1' descending along the rear wall surface 7 from behind the pump 10 is further weakened. Therefore, the generation of air entrainment vortices is further suppressed.
　上記各実施の形態では、図３に示すように、ボルト３６を用いて渦抑制部材１２をベルマウス２１の下端部に着脱自在に装着している。しかし、渦抑制部材１２を溶接等によってベルマウス２１の下端部に一体的に取り付けてもよい。この場合、渦抑制部材１２の湾曲壁３０に取付フランジ３１を設けず、渦抑制部材１２の湾曲壁３０の上端部をベルマウス２１の下端部に溶接してもよい。 In each of the above embodiments, the vortex suppressing member 12 is detachably attached to the lower end of the bell mouth 21 using bolts 36, as shown in FIG. However, the vortex suppressing member 12 may be integrally attached to the lower end portion of the bell mouth 21 by welding or the like. In this case, the upper end of the curved wall 30 of the vortex suppressing member 12 may be welded to the lower end of the bell mouth 21 without providing the mounting flange 31 on the curved wall 30 of the vortex suppressing member 12 .
　上記各実施の形態では、底板３４は矩形状である。しかし、底板３４は、円形、楕円形、四角形以外の多角形等の形状であってもよい。 In each of the above embodiments, the bottom plate 34 is rectangular. However, the bottom plate 34 may be circular, elliptical, polygonal other than square, or the like.
　上記各実施の形態では、底板３４は、湾曲壁３０の下端部３０ｂの位置に対して同一又は下端部３０ｂよりも上方位置に設けられている。しかし、底板３４は、下端部３０ｂよりも下方の位置に設けられていてもよい。 In each of the above embodiments, the bottom plate 34 is provided at the same position as the lower end portion 30b of the curved wall 30 or at a position above the lower end portion 30b. However, the bottom plate 34 may be provided at a position below the lower end portion 30b.

Claims (6)

  1. ポンプにおける下向きに開口したベルマウスに取付られる渦抑制部材であって、
    　ベルマウスの吸込口の周縁部における周方向の一部から下方に延び横断面円弧状に湾曲した湾曲壁と、
    　湾曲壁の下端部から湾曲壁の内側へ張り出した下部張り出し部材とを有していることを特徴とする渦抑制部材。     A vortex suppression member mounted in a downwardly opening bell mouth of a pump, comprising:
    a curved wall extending downward from a portion of the peripheral edge of the suction port of the bell mouth in the circumferential direction and having an arcuate cross section;
    A vortex suppressing member, comprising: a lower projecting member projecting inwardly of the curved wall from a lower end of the curved wall.
  2. 湾曲壁の内側を仕切る仕切壁が湾曲壁に設けられて、湾曲壁と仕切壁とで囲まれ且つ上下両方向が開口した中空体が形成されていることを特徴とする請求項１に記載の渦抑制部材。 2. The vortex according to claim 1, wherein the curved wall is provided with a partition wall that partitions the inside of the curved wall, and a hollow body that is surrounded by the curved wall and the partition wall and is open in both upper and lower directions is formed. suppression member.
  3. 吸込口の下方に対向する底板が仕切壁に取り付けられ、底板はベルマウスの軸心の延長線上に配置されていることを特徴とする請求項２に記載の渦抑制部材。 3. The vortex suppressing member according to claim 2, wherein a bottom plate facing the lower part of the suction port is attached to the partition wall, and the bottom plate is arranged on an extension of the axial center of the bell mouth.
  4. 仕切壁の上端部が湾曲壁の上端部よりも下位にあることを特徴とする請求項２又は請求項３に記載の渦抑制部材。 4. A vortex suppressing member according to claim 2, wherein the upper end of the partition wall is lower than the upper end of the curved wall.
  5. 上記請求項１から請求項４のいずれか１項に記載の渦抑制部材を備えたポンプであって、渦抑制部材がベルマウスに取り付けられていることを特徴とするポンプ。 A pump comprising the vortex suppressing member according to any one of claims 1 to 4, wherein the vortex suppressing member is attached to a bellmouth.
  6. 上記請求項５に記載のポンプを吸水槽に備えたポンプ設備であって、ベルマウスの吸込口が吸水槽内に設けられて吸水槽の後壁面の手前側にあり、渦抑制部材の湾曲壁が吸水槽の後壁面に対向していることを特徴とするポンプ設備。 A pump facility comprising the pump according to claim 5 in a suction tank, wherein the suction port of the bell mouth is provided in the suction tank and is located on the front side of the rear wall surface of the suction tank, and the curved wall of the vortex suppressing member. facing the rear wall surface of the suction sump.
PCT/JP2022/044957 2021-12-06 2022-12-06 Vortex suppression member for pumps, pump, and pump facility WO2023106299A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2021197419A JP2023083628A (en) 2021-12-06 2021-12-06 Vortex suppression member, pump and pumping equipment
JP2021-197419 2021-12-06

Publications (1)

Publication Number Publication Date
WO2023106299A1 true WO2023106299A1 (en) 2023-06-15

Family

ID=86730487

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/044957 WO2023106299A1 (en) 2021-12-06 2022-12-06 Vortex suppression member for pumps, pump, and pump facility

Country Status (2)

Country Link
JP (1) JP2023083628A (en)
WO (1) WO2023106299A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006299944A (en) * 2005-04-21 2006-11-02 Mitsubishi Heavy Ind Ltd Vertical pump
JP2010249120A (en) * 2009-03-26 2010-11-04 Ebara Corp Vortex prevention device and pump device
JP2017172379A (en) * 2016-03-22 2017-09-28 株式会社荏原製作所 Strainer and vertical shaft pump with strainer
JP2019105252A (en) * 2017-12-14 2019-06-27 株式会社荏原製作所 Pump including vortex breaker
JP2019132150A (en) * 2018-01-30 2019-08-08 株式会社荏原製作所 Pump with swirl restraining device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006299944A (en) * 2005-04-21 2006-11-02 Mitsubishi Heavy Ind Ltd Vertical pump
JP2010249120A (en) * 2009-03-26 2010-11-04 Ebara Corp Vortex prevention device and pump device
JP2017172379A (en) * 2016-03-22 2017-09-28 株式会社荏原製作所 Strainer and vertical shaft pump with strainer
JP2019105252A (en) * 2017-12-14 2019-06-27 株式会社荏原製作所 Pump including vortex breaker
JP2019132150A (en) * 2018-01-30 2019-08-08 株式会社荏原製作所 Pump with swirl restraining device

Also Published As

Publication number Publication date
JP2023083628A (en) 2023-06-16

Similar Documents

Publication Publication Date Title
KR101811779B1 (en) Anti-vortex device and double-suction vertical pump provided with the anti-vortex device
JP4573020B2 (en) Suction casing, suction flow path structure and fluid machine
JP2006125827A (en) Range hood
US20160356018A1 (en) Construction machine including engine
US20220381448A1 (en) Air guide box and internal-circulation range hood having the same
JP2010127590A (en) Outdoor unit for air conditioner, and air conditioner with the outdoor unit
WO2023106299A1 (en) Vortex suppression member for pumps, pump, and pump facility
WO2023106297A1 (en) Vortex suppression member of pump, pump, and pump facility
WO2023106298A1 (en) Vortex suppression member for pump, pump, and pump equipment
JP2005016315A (en) Centrifugal fan and its application
JP2015078679A (en) Pump
JP5324491B2 (en) Liquid pump vortex prevention device
JP5432336B2 (en) pump
JP6983090B2 (en) Pumps, vortex suppressors and pump equipment
JP2011127822A (en) Blower with silencing box
CN110701654B (en) Range hood and integrated stove
JP6596951B2 (en) Blower
CN110701655B (en) Fume exhaust fan
JP7476071B2 (en) Vertical Pump
CN219865608U (en) Centrifugal fan and range hood using same
JP2023131505A (en) vertical shaft pump
JP3882409B2 (en) Pump device with vortex generation prevention device
JP7178194B2 (en) Suction cover, horizontal shaft pump and pump gate
CN112879349B (en) Air inlet device, fan system with air inlet device and cleaning machine
CN216557295U (en) Noise-reduction type range hood

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22904227

Country of ref document: EP

Kind code of ref document: A1