WO2016178387A1 - Horizontal shaft submersible pump and suction cover used for horizontal shaft submersible pump - Google Patents

Horizontal shaft submersible pump and suction cover used for horizontal shaft submersible pump Download PDF

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Publication number
WO2016178387A1
WO2016178387A1 PCT/JP2016/062987 JP2016062987W WO2016178387A1 WO 2016178387 A1 WO2016178387 A1 WO 2016178387A1 JP 2016062987 W JP2016062987 W JP 2016062987W WO 2016178387 A1 WO2016178387 A1 WO 2016178387A1
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WO
WIPO (PCT)
Prior art keywords
suction
submersible pump
opening
upper wall
water level
Prior art date
Application number
PCT/JP2016/062987
Other languages
French (fr)
Japanese (ja)
Inventor
健一 山科
洋総 大橋
光博 岡田
典明 渡邉
順一 片山
智紀 吉田
大谷　友人
正樹 安倍
Original Assignee
株式会社石垣
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 株式会社石垣 filed Critical 株式会社石垣
Priority to JP2017516596A priority Critical patent/JP6504247B2/en
Priority to KR1020177028665A priority patent/KR102004207B1/en
Priority to CN201680021343.3A priority patent/CN107429701B/en
Priority to TW105113544A priority patent/TWI704287B/en
Publication of WO2016178387A1 publication Critical patent/WO2016178387A1/en

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    • 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
    • F04D13/02—Units comprising pumps and their driving means
    • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
    • F04D13/08—Units comprising pumps and their driving means the pump being electrically driven for submerged use
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02B—HYDRAULIC ENGINEERING
    • E02B7/00—Barrages or weirs; Layout, construction, methods of, or devices for, making same
    • E02B7/20—Movable barrages; Lock or dry-dock gates
    • 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
    • F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems

Definitions

  • This disclosure relates to a horizontal axis submersible pump as an internal water drainage facility installed in a culvert or the like and used for pumping rainwater or sewage, and a suction cover used for a horizontal axis submersible pump.
  • an open / close gate is installed on the tributary side, and the water on the main river side flows back into the tributary by closing the open / close gate when there is a heavy rain. Suppressed.
  • a pump gate having a horizontal axis submersible pump attached to an open / close gate is often used.
  • the pump gate often uses a horizontal axis submersible pump in order to discharge a large volume of water.
  • Patent document 1 is disclosing the pump gate which provided the suction bell mouth (suction cover) in the horizontal axis submersible pump, and was able to drain to a low water level.
  • the present invention provides a horizontal-axis submersible pump capable of maintaining operation at the rated rotation speed and suppressing repetition of stopping and starting of the pump even when the water level on the suction side is equal to or lower than the water level during drainage operation.
  • the purpose is to do.
  • a horizontal axis submersible pump is provided in a casing having a suction port and a discharge port, an impeller supported in the casing, a suction cover connected to the suction port, and the suction cover.
  • the first suction opening that opens at a position lower than the upper end of the impeller, and at least one of the suction cover and the casing are provided upstream of the impeller and open at a position higher than the upper end of the first suction opening.
  • a second suction opening is provided in a casing having a suction port and a discharge port, an impeller supported in the casing, a suction cover connected to the suction port, and the suction cover.
  • the horizontal-axis submersible pump operates while sucking in air even in the operation mode in which the impeller is not completely submerged, so that suction is performed while maintaining the operation at the rated rotational speed of the submersible motor that drives the impeller.
  • the water level lowering speed or rising speed can be suppressed. Therefore, the repetition frequency of ON / OFF of the submersible electric motor can be reduced.
  • the suction cover has an upper wall and a side wall extending downward from the upper wall, and the front edge of the upper wall has a position higher than both ends of the front edge, and the second suction opening May be an opening surrounded by a front edge and a straight line connecting both ends of the front edge.
  • the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the suction cover has an upper wall, a side wall extending downward from the upper wall, and a front wall extending downward from the upper wall, and the second suction opening penetrates the front wall. It may be a hole.
  • the suction cover allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
  • the suction cover has an upper wall, a side wall extending downward from the upper wall, and a front wall extending downward from the upper wall, and the first suction opening has a lower end of the front wall.
  • the second suction opening is connected to the first suction opening and is surrounded by at least one notch formed in the front wall and a straight line connecting the lower end of the front wall. It may be an open opening.
  • the suction cover allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
  • the suction cover has an upper wall and a side wall extending downward from the upper wall, and the first suction opening is an opening surrounded by the front edge of the upper wall and the lower end of the side wall,
  • the second suction opening communicates with the first suction opening, and is an opening surrounded by at least one notch formed in the upper wall and a straight line connecting the front edge of the upper wall, or the first suction opening. It is good also as an opening enclosed by the at least 1 or more notch formed in the side wall, and the straight line which connects the lower end of a side wall.
  • the suction cover allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
  • the suction cover may have an upper wall and a side wall extending downward from the upper wall, and the second suction opening may be an opening formed in the upper wall or the side wall.
  • the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the intake pipe is an intake port having one end connected to the suction cover or the casing and the other end opened, and the suction cover includes an upper wall and a side wall extending downward from the upper wall;
  • the second suction opening may be an intake port.
  • air can be suitably introduced into the suction cover even in the operation mode below the water level of the operation mode of all drainage.
  • the front edge of the upper wall of the suction cover or the lower end of the front wall extending downward from the upper wall of the suction cover is located 10 to 25% above the impeller diameter ratio from the lower end of the impeller. It may be a thing.
  • a flap gate that is provided on the side of the discharge port of the casing and that can be opened and closed by the pressure of the fluid discharged from the discharge port may be provided.
  • the flap gate is always open in each operation mode of total drainage and air / water mixture drainage, and water corresponding to each operation mode is discharged, and in the idling operation mode at the lower water level, the flap gate is blocked. Therefore, the fluid easily circulates and flows in the casing. Further, since the flap gate is opened and closed by the discharge pressure, it is not necessary to separately provide a driving device and a control device for opening and closing the flap gate, and the configuration can be simplified.
  • an air venting mechanism for discharging the air in the casing to the outside when the internal pressure of the casing reaches a predetermined pressure may be provided.
  • the air remaining in the casing can be suitably discharged.
  • the load on the submersible electric motor can be suppressed.
  • the suction cover used in the horizontal-axis submersible pump includes a discharge opening, an upper wall, a side wall extending downward from the upper wall, and a lower side extending from the upper wall.
  • a second suction opening that is an opening surrounded by a straight line.
  • the suction cover allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
  • the suction cover used in the horizontal-axis submersible pump includes a discharge opening, an upper wall, a side wall extending downward from the upper wall, a front edge of the upper wall, and a lower end of the side wall.
  • the first suction opening has at least one notch formed in the side wall and a second suction opening that is an opening surrounded by a straight line connecting the lower ends of the side walls.
  • the suction cover allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise.
  • the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
  • the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
  • a horizontal-axis submersible pump capable of maintaining operation at the rated rotational speed and suppressing repetition of stopping and starting of the pump even when the water level on the suction side is equal to or lower than the water level during drainage operation. can do.
  • FIG. 1 is a diagram showing a configuration of a horizontal-axis submersible pump according to an embodiment of the present invention.
  • FIG. 2 is a view showing the shape of the suction cover in the first embodiment.
  • FIG. 3 is a view showing another shape of the suction cover in the first embodiment.
  • FIG. 4 is a diagram illustrating another shape of the suction cover according to the first embodiment.
  • FIG. 5 is a diagram showing a configuration of a pump gate system using a horizontal-axis submersible pump.
  • FIG. 6 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the first embodiment.
  • FIG. 7 is a diagram illustrating a pump operation in the full drainage mode in the first embodiment.
  • FIG. 1 is a diagram showing a configuration of a horizontal-axis submersible pump according to an embodiment of the present invention.
  • FIG. 2 is a view showing the shape of the suction cover in the first embodiment.
  • FIG. 3 is a view showing another shape of the
  • FIG. 8 is a diagram showing a pump operation in the air / water mixed discharge mode in the first embodiment.
  • FIG. 9 is a diagram illustrating the pump operation in the idling mode in the first embodiment.
  • FIG. 10 is a diagram showing a configuration of an air bleeding mechanism installed in the horizontal-axis submersible pump.
  • FIG. 11 is a diagram illustrating the shape of the suction cover according to the second embodiment.
  • FIG. 12 is a diagram showing the shape of the intake section in the second embodiment.
  • FIG. 13 is a diagram showing another shape of the intake section in the second embodiment.
  • FIG. 14A is a diagram illustrating another shape of the intake section in the second embodiment.
  • FIG. 14B is a diagram showing another shape of the intake section in the second embodiment.
  • FIG. 15 is a view showing another shape of the intake section in the second embodiment.
  • FIG. 16 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the second embodiment.
  • FIG. 17 is a diagram illustrating a pump operation in the full-drainage mode in the second embodiment.
  • FIG. 18 is a diagram illustrating a pump operation in the air / water mixture discharge mode according to the second embodiment.
  • FIG. 19 is a diagram illustrating a pump operation in the idling mode in the second embodiment.
  • FIG. 20 is a diagram illustrating an outer shape of a horizontal-axis submersible pump according to the third embodiment.
  • FIG. 21 is a diagram showing another external shape of the horizontal-axis submersible pump according to the third embodiment.
  • FIG. 22 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the third embodiment.
  • FIG. 23 is a diagram illustrating a pump operation in the full drainage mode in the third embodiment.
  • FIG. 24 is a diagram illustrating a pump operation in the air / water mixture discharge mode according to the third embodiment.
  • FIG. 25 is a diagram illustrating a pump operation in the idling mode in the third embodiment.
  • FIG. 26 is a diagram illustrating an outer shape of a horizontal-axis submersible pump in the fourth embodiment.
  • FIG. 27 is a diagram showing another external shape of the horizontal-axis submersible pump in the fourth embodiment.
  • FIG. 28 is a diagram showing another external shape of the horizontal-axis submersible pump in the fourth embodiment.
  • FIG. 23 is a diagram illustrating a pump operation in the full drainage mode in the third embodiment.
  • FIG. 24 is a diagram illustrating a pump operation in the air / water mixture discharge mode according to the third embodiment.
  • FIG. 29 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the fourth embodiment.
  • FIG. 30 is a diagram illustrating a pump operation in the full-volume drainage mode according to the fourth embodiment.
  • FIG. 31 is a diagram illustrating a pump operation in the air / water mixed discharge mode according to the fourth embodiment.
  • FIG. 32 is a diagram illustrating a pump operation in the idling mode in the fourth embodiment.
  • FIG. 33 is a diagram showing an outer shape of a horizontal-axis submersible pump in the fifth embodiment.
  • FIG. 34A is a diagram illustrating a configuration of an air adjustment mechanism in the fifth embodiment.
  • FIG. 34B is a diagram showing another configuration of the air adjustment mechanism in the fifth embodiment.
  • FIG. 35 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the fifth embodiment.
  • FIG. 36 is a diagram illustrating a pump operation in the full-volume drainage mode according to the fifth embodiment.
  • FIG. 37 is a diagram showing a pump operation in the air / water mixture discharge mode according to the fifth embodiment.
  • FIG. 38 is a diagram illustrating a pump operation in the idling mode in the fifth embodiment.
  • FIG. 39 is a diagram showing a configuration of a horizontal-axis submersible pump in the sixth embodiment.
  • FIG. 40A is a front view of main parts of the impeller.
  • FIG. 40B is a development view of the impeller at the height position of the front edge of the suction cover.
  • FIG. 40A is a front view of main parts of the impeller.
  • FIG. 40B is a development view of the impeller at the height position of the front edge of the suction cover.
  • FIG. 41 is a diagram illustrating the shape of the suction cover according to the sixth embodiment.
  • FIG. 42 is a graph showing the performance curve of the horizontal axis submersible pump.
  • FIG. 43 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the sixth embodiment.
  • FIG. 44 is a diagram illustrating a pump operation in the total amount draining mode in the sixth embodiment.
  • FIG. 45 is a diagram showing a pump operation in the idling mode in the sixth embodiment.
  • FIG. 46 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 47 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 48 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 46 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 49 is a diagram showing the shape of a suction cover as another embodiment.
  • FIG. 50 is a diagram illustrating a shape of a suction cover as another embodiment.
  • FIG. 51 is a diagram illustrating a shape of a suction cover as another embodiment.
  • FIG. 52 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 53 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 54 is a view showing the shape of a suction cover as another embodiment.
  • FIG. 55 is a diagram showing the shape of a suction cover as another embodiment.
  • FIG. 1 is a side sectional view showing a configuration of a horizontal-axis submersible pump 1 according to a first embodiment of the present invention.
  • the horizontal axis submersible pump 1 is a horizontal axis axial flow type submersible pump capable of discharging a large volume of water, and includes a casing 2, an impeller 3, a main shaft 4, guide vanes 5, and an underwater electric motor 6. Is provided.
  • the casing 2 is a cylinder having a suction port and a discharge port, and fluid (water and air) passes through the inside thereof.
  • an impeller 3, a guide blade 5 and an underwater electric motor 6 are arranged from the suction side.
  • the impeller 3 is selected according to the specifications of the drainage station, and is, for example, an axial flow blade or a mixed flow blade.
  • the main shaft 4 transmits the rotational force generated by the submersible electric motor 6 to the impeller 3, and one end is connected to the submersible electric motor 6 and the other end is connected to the impeller 3. That is, the impeller 3 is supported via the main shaft 4 by the underwater motor 6 held in the casing 2.
  • the guide vanes 5 define the flow direction of the fluid flowing through the casing 2.
  • the horizontal-axis submersible pump 1 may be provided with a flap gate 9 supported on the discharge side of the casing 2 so as to be opened and closed.
  • the flap gate 9 can be provided directly or indirectly at the outlet of the casing 2.
  • the casing 2 and the flap gate 9 may be connected to each other through a sluice wall to which the horizontal axis submersible pump 1 is attached.
  • the sluice wall there is a gate door body of a pump gate system as described later.
  • the flap gate 9 is closed by its own weight when the discharge pressure of the horizontal-axis submersible pump 1 is low, and allows drainage by opening around the upper fulcrum when the discharge pressure is high.
  • the horizontal axis submersible pump 1 is provided with a suction cover 7 on the suction side of the casing 2 with the opening 8 facing downward.
  • the suction cover 7 is made of, for example, a casting, and guides the fluid sucked from the opening 8 to the suction port of the casing 2.
  • FIG. 2 is a three-side view showing the shape of the suction cover 7 in the present embodiment.
  • the suction cover 7 includes an upper wall 10, two side walls 11 extending downward from both ends of the upper wall 10, and a flange 12 connected to the casing 2 and having a discharge opening.
  • the upper wall 10 is inclined downward toward the suction side (left direction in the side view).
  • the lower end of the side wall 11 is inclined from both ends of the front edge 13 of the upper wall 10 to the vicinity of the lower part of the casing 2 of the horizontal axis submersible pump 1.
  • the opening 8 of the suction cover 7 is a first suction opening in the present embodiment, which is provided in an inclined state so that the suction side is higher than the other side.
  • the front edge 13 of the upper wall 10 forms a convex portion whose central portion is higher than both end portions.
  • the suction portion 14 of the suction cover 7 is a space surrounded by a straight line (two-dot chain line) connecting both end portions of the front edge 13 and the convex front edge 13, and is a second suction opening in the present embodiment. is there.
  • the front edge 13 is not limited to a straight line, and the central portion of the front edge 13 may protrude toward the suction side.
  • start end 14a at the highest position of the intake section 14 and the end end 14b at the lowest position can be operated in an air-water mixed discharge mode, which will be described later, according to the specifications of the drainage pump station and the horizontal axis submersible pump 1. Set to position.
  • FIG. 3 is a two-side view showing another shape of the suction cover 7 in the present embodiment.
  • the shape of the suction cover 7 is not limited to that shown in FIG. 2, but may be as shown in FIG.
  • the suction cover 7 shown in FIG. 3 has a front wall 15 extending downward from the front edge 13 of the upper wall 10.
  • the second suction opening in the present embodiment is a plurality of intake holes 16 penetrating the front wall 15.
  • the lower end (end portion) of the side wall 11 has a predetermined inclination angle from the lower end of the front wall 15 toward the flange 12.
  • the extending length of the front wall 15 is appropriately set according to the operation status of the air / water mixed discharge mode and idling mode described later.
  • the shape of the intake hole 16 can be appropriately selected from a circular shape, a long hole shape, a slit shape, and the like, and the hole diameter of the intake hole 16 and the width of the slit are also appropriately determined according to the operating conditions.
  • FIG. 4 is a two-side view showing another shape of the suction cover 7 in the present embodiment.
  • the suction cover 7 shown in FIG. 4 has a front wall 15 that has the front edge 13 of the upper wall 10 horizontal and extends downward from the front edge 13.
  • the front wall 15 has at least one or more cutouts communicating with the opening 8, and when viewed as a whole, the cutout has a saw shape or a wave shape.
  • the second suction opening in the present embodiment is an intake portion 14 as an opening surrounded by a notch and a straight line (two-dot chain line) connecting the lower ends of the front wall 15.
  • the shape of the side wall 11 and the extension length of the front wall 15 are the same as those of the suction cover 7 shown in FIG.
  • FIG. 5 is a schematic diagram showing a configuration of a pump gate system 17 using the horizontal axis submersible pump 1.
  • the pump gate system 17 includes a pump gate 19, a rack bar 21 that hangs down from the top wall 20 and lifts the gate door 18, and an opening / closing device 22 that moves the rack bar 21 up and down to raise and lower the pump gate 19. .
  • the pump gate 19 detachably installs the horizontal axis submersible pump 1 in the gate door body 18 and opens and closes a water channel such as a river. Water is supplied from the upstream side (left side in the figure) to the downstream side (right side in the figure). Drain. Specifically, during normal times, the water in the pump suction side (upstream side) water channel is naturally drained into the pump discharge side (downstream side) water channel with the gate door 18 raised. On the other hand, when the outside water level on the downstream side rises due to heavy rain or the like, the gate door 18 is lowered by driving the switch 22 to close the water channel, and the horizontal axis submersible pump 1 causes the upstream water to flow downstream. Force drain. In the pump gate system 17 according to the present embodiment, the pump gate 19 is vertically lowered to close the water channel, but the water channel may be closed by a known technique such as swinging or rotation.
  • FIG. 6 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1. 6 explains that the shape of the suction cover 7 is as shown in FIG. 3, the same applies to the suction cover 7 shown in FIG. 2 or FIG. 4.
  • the horizontal axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M) on the suction side. Specifically, the total amount drainage mode M1, the air / water mixed discharge mode M2, and the idling mode M3 are performed.
  • the full drainage mode M1 is performed when the water level on the suction side exceeds the water level H.
  • the air / water mixture discharge mode M2 is performed when the water level on the suction side is equal to or lower than the water level H and exceeds the water level M.
  • the idling mode M3 is performed when the water level on the suction side is equal to or lower than the water level M.
  • a specific water level L (L ⁇ M) the horizontal submersible pump 1 stops operation.
  • the water level H is set at the position of the upper end 16 a of the suction hole 16 of the suction cover 7.
  • the water level M is set at the upper end of the opening 8 of the suction cover 7.
  • the water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
  • the suction cover 7 has the shape shown in FIG. 2
  • the water level H is set to the position of the start end 14 a of the intake portion 14 of the suction cover 7, and the water level M is set to the position of the end 14 b of the intake portion 14. Is set.
  • FIG. 7 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 when the operation mode is the full drainage mode M1 (suction side water level> water level H).
  • the total amount draining mode M1 is an operation mode in which the entire amount of water sucked on the upstream side is discharged downstream.
  • the horizontal axis submersible pump 1 is activated, and the horizontal axis submersible pump 1 operates at the rated rotation speed in the full-volume drainage mode M1 to the downstream side. Drain.
  • all the openings (intake holes 16 and openings 8) communicating with the inside of the horizontal axis submersible pump 1 are submerged, and the discharge side flap gate 9 is opened by the discharge pressure of the horizontal axis submersible pump 1. It has become.
  • the operation start timing of the horizontal axis submersible pump 1 may be determined after a control device (not shown) detects that the water level H has been exceeded by a known water level gauge or the like. You may determine automatically based on the preset start time etc., without detecting H.
  • FIG. 8 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 when the operation mode is the air / water mixture discharge mode M2 (water level H ⁇ suction side water level> water level M).
  • the operation mode shifts to the air / water mixture discharge mode M2.
  • the air / water mixture discharge mode M2 is an operation mode in which drainage is performed by operation at the rated rotational speed while inhaling a small amount of air together with water.
  • the opening 8 is a submerged water level.
  • air can be sucked from the suction hole 16 while sucking water from the opening 8.
  • the amount of drainage is determined from the relationship between the water level and the intake air amount.
  • the discharge pressure of the horizontal axis submersible pump 1 is lower than that in the full discharge mode M1.
  • the flap gate 9 remains open.
  • FIG. 9 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 when the operation mode is the idling mode M3 (water level M ⁇ suction side water level> water level L).
  • the operation mode shifts from the air / water mixed discharge mode M2 to the idling mode M3.
  • the idling mode M3 is a mode in which a so-called standby operation is performed, and is an operation mode in which operation at the rated rotational speed is maintained while a large amount of air is sucked together with water.
  • Specific water level is a level at which part of the opening 8 of the suction cover 7 is open to the atmosphere but part of the impeller 3 is submerged.
  • the flap gate 9 In the idling mode M3, since the water and air circulate and flow in the casing 2 and the discharge pressure is low, the flap gate 9 is basically in a closed state. However, when the downstream water level falls, the flap gate 9 may open. Further, even when the operation at the rated rotation speed is performed with the flap gate 9 closed, since a large amount of air is mixed, the hydraulic power is low and the pump power can be prevented from increasing.
  • the horizontal axis submersible pump 1 determines that the possibility of re-drainage is low, depending on the estimated amount of inflow on the suction side, and stops operation.
  • the timing of stopping the operation of the horizontal axis submersible pump 1 may be determined after a control device (not shown) detects a state in which the water level below the water level L continues for a certain period of time using a known water level gauge or the like. Alternatively, it may be automatically determined based on a preset start time without detecting the water level L.
  • the operation mode is shifted to another operation mode.
  • the operation mode shifts to an idling mode M3 in which water and air are sucked from the opening 8 and air is sucked from the intake hole 16 and the water in the casing 2 is stirred while the flap gate 9 is closed.
  • the operation mode is an air-water mixture that drains water while sucking air from the opening 8 and sucking air from the intake hole 16. Transition to the discharge mode M2. Further, when the water level rises during the air / water mixture discharge mode M2 and the water level on the suction side exceeds the water level H, the operation mode shifts to the full-volume drainage mode M1 for sucking water from the opening 8 and the intake hole 16.
  • the horizontal axis submersible pump 1 appropriately determines whether to resume the operation according to the estimated amount of inflow on the suction side and the specifications of the drainage station or the horizontal axis submersible pump 1 after the operation is stopped.
  • the timing of restarting operation may be any water level on the suction side.
  • the horizontal axis submersible pump 1 further includes an air venting mechanism.
  • FIG. 10 is a schematic diagram showing the configuration of the air vent mechanism 23 installed in the horizontal-axis submersible pump 1. For example, when the water level rises and the operation mode shifts from the air / water mixture discharge mode M2 to the full-volume drainage mode M1, the air staying in the casing 2 is discharged to the outside by the air vent mechanism 23. .
  • the air vent mechanism 23 is, for example, a flap-type gate having a small opening that can be installed above the flap gate 9 attached to the discharge side of the horizontal-axis submersible pump 1.
  • the air venting mechanism 23 may be any mechanism provided with a mechanism that automatically operates when the internal pressure reaches a predetermined pressure as the moisture in the casing 2 increases. It may be an installed air vent valve or the like.
  • the horizontal-axis submersible pump 1 has the second suction opening (such as the intake section 14) that opens at a position higher than the upper end of the first suction opening (opening section 8), so that the water level on the suction side changes.
  • the operation mode can be automatically switched according to the operation. Specifically, when the water level on the suction side is higher than the upper end of the second suction opening, the horizontal-axis submersible pump 1 is operated in the full drainage mode by immersing the first and second suction openings.
  • the horizontal-axis submersible pump 1 sucks water from the first suction opening while taking in the second suction. Operate in a mixed-air drainage mode that draws air from the opening. Further, when the water level on the suction side is lower than the upper end of the first suction opening, the horizontal-axis submersible pump 1 operates in an idling mode in which air is sucked from the first and second suction openings to circulate and flow water in the casing. Do.
  • the whole volume drainage mode is switched to the air / water mixed drainage mode, or the air / water mixed drainage mode is shifted to the idling mode.
  • the horizontal-axis submersible pump 1 can suppress the rate of decrease in the water level on the suction side while maintaining the operation at the rated rotational speed of the submersible electric motor 6 that drives the impeller 3.
  • the idling mode is switched to the air / water mixing / draining mode, or the air / water mixing / draining mode is shifted to the full amount draining mode.
  • the horizontal axis submersible pump 1 can suppress the rising speed of the water level on the suction side while maintaining the operation of the submersible electric motor 6 at the rated rotational speed. Therefore, the repetition frequency of ON / OFF of the underwater electric motor 6, that is, the pump can be reduced.
  • the horizontal axis submersible pump 1 can realize transition between the respective operation modes according to the water level without providing a complicated control device or the like.
  • the suction cover 7 as shown in FIG. 2, generation
  • the intake area at the second suction opening increases as the water level on the suction side decreases, so that the amount of air sucked in is suitably increased, and between each operation mode is smooth. Can be migrated to.
  • the suction cover 7 since the intake holes 16 or the intake portions 14 are provided in the front wall 15, air flows uniformly along the front edge 13. Therefore, rapid inflow of air can be suppressed, and vibration and noise can be suppressed. Further, by providing the front wall 15 with the intake holes 16 and the like, the adjustment of the inflow air amount can be facilitated and the inflow of foreign matter can be suppressed.
  • a horizontal axis submersible pump can be provided.
  • FIG. 11 is a three-side view showing the shape of the suction cover 7 in the present embodiment. Compared with the suction cover 7 in the first embodiment shown in FIG. 2, the overall shape of the suction cover 7 is substantially the same, but the shape and formation position of the intake portion 14 are different.
  • FIG. 12 is a plan view showing the shape of the intake portion 14 provided on the upper wall 10 as an example of the second suction opening in the present embodiment.
  • the intake portion 14 is formed from a start end 14a located near the flange 12 with a predetermined width toward an end end 14b located near the front edge 13, and is an opening penetrating the front surface and the back surface of the upper wall 10. Air can flow freely.
  • each corner may be formed in an arc shape.
  • the width is gradually increased toward the front edge 13 of the upper wall 10 (the end 14b side of the intake portion 14) so that the opening area increases from the start end 14a toward the end 14b when the water level decreases.
  • operation mode can be smoothly changed with the fall of a water level.
  • the start end 14a, the end end 14b and the width of the intake portion 14 are appropriately determined from conditions such as the inclination angle of the upper wall 10 and the pump diameter.
  • FIG. 13 is a plan view showing the shape of a plurality of intake holes 30 provided in the upper wall 10 as another example of the second suction opening in the present embodiment.
  • the formation conditions of the plurality of intake holes 30 satisfy the same conditions as those of the intake portion 14 shown in FIG. Further, the diameter of the intake hole 30 and the like are appropriately determined according to the operating conditions of the pump.
  • FIG. 14A is a plan view showing the shape of a plurality of slits 32 provided in the upper wall 10 as another example of the second suction opening in the present embodiment, and the shape of one slit 32 is triangular, and An example in which a plurality of such slits 32 are arranged in a direction parallel to the main shaft 4 is shown.
  • FIG. 14B shows an example in which the shape of one slit 32 is rectangular and a plurality of such slits 32 are arranged in a direction perpendicular to the main shaft 4.
  • the formation conditions of the plurality of slits 32 also satisfy the same conditions as those of the intake section 14 shown in FIG.
  • the width of the slit 32 and the like are appropriately determined according to the operating conditions of the pump. As shown in FIGS. 13 and 14, by forming a portion corresponding to the intake portion 14 with a plurality of openings, the strength of the upper wall 10 of the suction cover 7 can be maintained, and the suction cover 7 is formed of a thin plate. be able to.
  • FIG. 15 is a side view showing the shape of the intake portion 14 provided on the side wall 11 as another example of the second suction opening in the present embodiment.
  • the intake portion 14 is formed so that the width toward the suction side gradually increases from the start end 14a located at the upper portion (the direction in which the water level rises) to the end end 14b located at the lower portion (the direction in which the water level decreases). This is an opening that penetrates the front and back surfaces of the side wall 11 and allows water and air to flow freely.
  • each corner may be formed in an arc shape.
  • the intake portion 14 When the intake portion 14 is submerged, water is also absorbed from the intake portion 14, and when the water level is lowered, air gradually flows into the suction cover 7 from the start end 14 a side of the intake portion 14. Also in this case, by gradually increasing the width to the lower side of the side wall 11 so that the opening area increases from the start end 14a toward the end end 14b when the water level is lowered, the operation mode can be smoothly shifted as the water level is lowered. Can do.
  • the intake portion 14 formed in the side wall 11 may be a plurality of intake holes 30, a plurality of slits 32, and the like, as in the case of being formed in the upper wall 10.
  • FIG. 16 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment.
  • the horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3.
  • H is set at the position of the start end 14 a of the intake portion 14 of the suction cover 7.
  • the water level M is set at the top position of the leading edge 13.
  • the water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
  • FIG. 17 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H).
  • the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
  • FIG. 18 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ⁇ suction side water level> water level M).
  • the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
  • FIG. 19 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ⁇ suction side water level> water level L).
  • the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
  • the horizontal-axis submersible pump according to the first and second embodiments is that the intake portion 14 as the second suction opening is formed not in the suction cover 7 but in the casing 2. Different from 1.
  • the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
  • FIG. 20 is a side sectional view showing the outer shape of the horizontal axis submersible pump 1 according to the present embodiment.
  • the overall shape of the suction cover 7 is substantially the same as that of the suction cover 7 in the first embodiment shown in FIG. 2, but the suction portion 14 does not exist in the suction cover 7 in this embodiment.
  • an intake portion 14 including a plurality of intake holes penetrating the outside and the inside of the casing 2 is formed. ing.
  • the plurality of intake holes are formed from the start end 14a near the top of the cylindrical casing 2 to the end 14b near the center of the cylinder width of the casing 2 along the circumferential direction.
  • the start end 14a is an intake hole positioned at the highest water level
  • the end end 14b is an intake hole positioned at the lowest water level.
  • the plurality of intake holes are arranged in the same quantity (the same opening area) from the start end 14a to the end end 14b.
  • water is also absorbed from the intake portion 14, and when the water level decreases, air gradually flows into the suction cover 7 from the start end 14 a side of the intake portion 14. .
  • FIG. 21 is a plan view showing another external shape of the horizontal-axis submersible pump 1 according to the present embodiment.
  • the number of intake holes in the plurality of intake holes constituting the intake section 14 as shown in FIG. 20 is increased so that the opening area increases from the start end 14a toward the end end 14b when the water level decreases. As a result, the operation mode can be smoothly shifted as the water level decreases.
  • the shape of the plurality of intake holes constituting the intake portion 14 is not limited to a circular shape, and may be, for example, a slit shape and can be selected as appropriate. Further, the hole diameter of the intake hole, the width of the slit, and the like are appropriately determined according to the operating conditions of the horizontal axis submersible pump 1. Further, the start end 14a, the end end 14b and the width of the intake section 14 are appropriately determined according to the machine field and the operating conditions of the horizontal axis submersible pump 1.
  • FIG. 22 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment.
  • the horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. It has the same points as the first and second embodiments.
  • the water level H is set at the position of the start end 14 a of the intake portion 14 of the casing 2.
  • the water level M is set at the top position of the leading edge 13.
  • the water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
  • FIG. 23 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H).
  • the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
  • FIG. 24 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ⁇ suction side water level> water level M).
  • the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
  • FIG. 25 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ⁇ suction side water level> water level L).
  • the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
  • the horizontal-axis submersible pump according to the present embodiment includes an intake pipe that is an intake port having one end connected to the suction cover 7 or the casing 2 and the other end opened, and the other intake port is defined as a second suction opening. This is different from the horizontal axis submersible pump 1 according to the first to third embodiments.
  • the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
  • FIG. 26 is a side view showing the outer shape of the horizontal axis submersible pump 1 according to the present embodiment.
  • the overall shape of the suction cover 7 is substantially the same as that of the suction cover 7 in the first embodiment shown in FIG. 2, but an intake pipe 14 is connected to the suction cover 7 in the present embodiment.
  • one end of the intake pipe 14 is connected to the side wall 11 of the suction cover 7 and communicates with the inside of the suction cover 7.
  • the intake pipe 14 extends upward by a predetermined length and is bent in an inverted U shape.
  • the other end of the intake pipe 14 is opened downward as an intake port 14a.
  • the intake port 14a and the inside of the pipe are prevented from being blocked by floating substances on the water surface.
  • the other end may be closed and the intake port 14 a may be provided on the side surface of the intake pipe 14.
  • the direction of the bent pipe of the intake pipe 14 is not particularly limited, but is opened above the upper wall 10 of the suction cover 7 in order to suppress damage due to collision with floating substances on the water surface. It is desirable to project the protective wall 31 upward from the front edge 13 of the wall 10. Further, the position in the height direction of the intake port 14a and the pipe diameter of the intake pipe 14 are appropriately determined from the operating conditions such as the machine field and the specifications of the horizontal axis submersible pump 1.
  • FIG. 27 is a side view showing another external shape of the horizontal-axis submersible pump 1 according to the present embodiment.
  • One end of the intake pipe 14 may be connected to the upper wall 10 of the suction cover 7 as shown in FIG.
  • FIG. 28 is a side view showing another external shape of the horizontal axis submersible pump 1 according to the present embodiment.
  • One end of the intake pipe 14 may be connected to the side wall of the casing 2 as shown in FIG. As described above, as long as one end of the intake pipe 14 is connected to a position where air is sucked into the upstream side of the impeller 3 of the horizontal submersible pump 1, the position and shape of the intake pipe 14 are not limited.
  • FIG. 29 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment.
  • the horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. This is the same as in the first to third embodiments.
  • the water level H is set at the position of the intake port 14 a of the intake pipe 14.
  • the water level M is set at the top position of the leading edge 13.
  • the water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
  • FIG. 30 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H).
  • the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
  • FIG. 31 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ⁇ suction side water level> water level M).
  • the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
  • FIG. 32 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ⁇ suction side water level> water level L).
  • the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
  • the horizontal axis submersible pump according to the present embodiment is the same as the fourth embodiment in that it includes an intake pipe that is an intake port having one end connected to the suction cover 7 or the casing 2 and the other end open.
  • the horizontal axis submersible pump according to the present embodiment is characterized in that the second intake opening is not used for water level judgment for determining the operation mode.
  • the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
  • FIG. 33 is a side view showing the outer shape of the horizontal-axis submersible pump 1 according to the present embodiment.
  • the overall shape of the suction cover 7 is substantially the same as that of the suction cover 7 in the first embodiment shown in FIG. 2, but an intake pipe 14 is connected to the suction cover 7 in the present embodiment.
  • one end of the intake pipe 14 is connected to the side wall 11 of the suction cover 7 and communicates with the inside of the suction cover 7.
  • the intake pipe 14 extends upward by a predetermined length.
  • the other end of the intake pipe 14 is bent horizontally and opened as an intake port 14a. The other end may be closed and the intake port 14 a may be provided on the side surface of the intake pipe 14.
  • the intake port 14a is positioned above the water level in the air / water mixture discharge mode M2 so that air can be drawn from the intake port 14a in the air / water mixture discharge mode M2.
  • the intake port 14a is desirably opened to a position above the maximum water level of the water storage tank.
  • a protective wall 31 or the like may be provided as necessary in order to suppress damage due to collision between the intake pipe 14 and floating matter on the water surface.
  • one end of the intake pipe 14 is connected to a position where air is sucked into the upstream side of the impeller 3 of the horizontal axis submersible pump 1, it may be connected to the upper wall 10 of the suction cover 7, the casing 2, or the like.
  • the pipe diameter of the intake pipe 14 and the like are appropriately determined from the operating conditions such as the machine field and the specifications of the horizontal axis submersible pump 1.
  • the intake pipe 14 includes an air amount adjusting mechanism therein.
  • 34A and 34B are schematic views showing the configuration of the air amount adjustment mechanism 33.
  • the air amount adjusting mechanism 33 supplies a predetermined amount of air to the horizontal axis submersible pump 1 in accordance with the pump internal pressure.
  • a resistor 33a such as an orifice plate can be used as shown in FIG. 34A, or a pressure valve 33b that opens and closes with a predetermined pressure as a threshold as shown in FIG. 34B. It can also be used.
  • the operation mode of the horizontal-axis submersible pump 1 is switched to the air / water mixing / discharging mode M2 by flowing a predetermined amount of air when the water level on the suction side is lowered.
  • the operation mode of the horizontal-axis submersible pump 1 is switched to the air / water mixing / discharging mode M2 by flowing a predetermined amount of air when the water level on the suction side is lowered.
  • the pushing pressure by the water head is lowered, and the upstream side (suction side) of the impeller 3 operating at the rated rotational speed becomes a negative pressure.
  • the negative pressure becomes a negative pressure larger than the resistance value of the air amount adjusting mechanism 33 (or the pressure valve is opened by detecting the set pressure)
  • the resistance value, the set pressure, and the like of the air amount adjusting mechanism 33 are appropriately set according to the specifications and operating conditions of the horizontal
  • FIG. 35 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment.
  • the horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. This is the same as the first to fourth embodiments.
  • the water level H is defined in advance as the upper end of the air / water mixture discharge mode M2.
  • the air quantity adjustment mechanism 33 is preset so that it may become the air-water mixing discharge mode M2 when the suction side water level becomes the water level H.
  • the water level M is set at the top position of the leading edge 13.
  • the water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
  • FIG. 36 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H).
  • the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
  • all the openings (air amount adjusting mechanism 33 and opening 8) communicating with the inside of the horizontal axis submersible pump 1 are not only submerged but also all closed. It is also included if you are.
  • FIG. 37 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ⁇ suction side water level> water level M).
  • the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
  • the air amount adjustment mechanism 33 is set in advance to a resistance value at which intake starts at the upper water level of the air / water mixture discharge mode M2, the operation mode is changed to the air / water mixture discharge mode M2. Switch.
  • FIG. 38 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ⁇ suction side water level> water level L).
  • the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
  • the horizontal-axis submersible pump 1 is configured to be in a full drainage mode so that it is easy to understand that the height position of the front edge 13 and the like of the suction cover 7 is defined based on the position of the impeller 3. And only two operation modes, i.e., idling mode. However, even in this case, an air-water mixed state exists at the time of transition between the full drainage mode and the idling mode. However, the air / water mixed state referred to in the present embodiment is different from the operation mode positively provided to obtain the effects of the present invention, such as the air / water mixed discharge mode M2 described in the above embodiments. Is. Therefore, the content of this embodiment is applicable also to the horizontal-axis submersible pump 1 which concerns on each said embodiment which has three operation modes including air-water mixing discharge mode.
  • FIG. 39 is a side sectional view showing the configuration of the horizontal axis submersible pump 1 according to the present embodiment.
  • the horizontal axis submersible pump 1 according to this embodiment differs from the first embodiment in that the height position A of the front edge 13 of the suction cover 7 is defined based on the position of the impeller 3. .
  • FIG. 40A is a front view of the main part of the impeller 3 when one blade of the impeller 3 is viewed from the direction of the rotation axis.
  • the position corresponding to the height position of the front edge 13 of the suction cover 7 is A according to the sign of the height position of the front edge 13, the position of the boss portion of the impeller 3 is Ai, and the impeller 3.
  • the position of the outer end of is Ao.
  • FIG. 40B is a development view of the impeller 3 corresponding to each position shown in FIG. 40A.
  • the discharge angle at position A is ⁇
  • the discharge angle at position Ai is ⁇ i
  • the discharge angle at position Ao is ⁇ o.
  • the pressure applied to the fluid discharged at a position where ⁇ is large is high, and the pressure applied to the fluid discharged at a position where ⁇ is small is low.
  • the operation mode changes according to the inflow ratio of water and air.
  • the casing 2 is closed at the rated speed and with the flap gate 9 closed. It is possible to maintain the state in which the water is retained up to the water level at which the submersible electric motor 6 is submerged.
  • the water level at the predetermined discharge angle ⁇ is 10 to 25% above the impeller diameter ratio from the lower end of the impeller 3, and preferably 10 to 20% above.
  • FIG. 41 is a three-side view showing the shape of the suction cover 7 in the present embodiment.
  • the suction cover 7 includes an upper wall 10, two side walls 11 extending downward from both side ends of the upper wall 10, and a flange 12 connected to the casing 2.
  • the upper wall 10 is inclined downward toward the suction side (left direction in the side view).
  • the lower end of the side wall 11 is inclined from both ends of the front edge 13 of the upper wall 10 to the vicinity of the lower part of the casing 2 of the horizontal axis submersible pump 1.
  • the leading edge 13 is located up to the water level near the lower end of the impeller 3. More specifically, it is desirable to be located 10 to 25% above the impeller diameter ratio from the lower end of the impeller.
  • the opening 8 of the suction cover 7 is a first suction opening in the present embodiment, which is provided in an inclined state so that the suction side is higher than the other side.
  • air gradually flows into the suction cover 7 from below the front edge 13 located at the top of the opening 8. Since the front edge 13 is located at the height near the lower end of the impeller 3, it is possible to operate in the full drainage mode until the low water level, and during operation in the idling mode, noise is suppressed and the casing 2 Can prevent water splashing.
  • the position of the front edge 13 is set to the water level near the lower end of the impeller 3, specifically, 10 to 25% above the impeller diameter ratio from the lower end of the impeller 3.
  • the present invention is not limited to the form, and can be applied to various suction covers 7 employed in the above embodiments.
  • the position of the front edge 13 here corresponds to the position of the lower end of the front wall 15.
  • FIG. 42 is a graph showing the performance curve of the horizontal axis submersible pump 1, wherein the horizontal axis indicates the flow rate and the vertical axis indicates the lift and power.
  • the specification point flow rate of the full drainage operation at normal time is Q1, and the head is H1.
  • the power is P1 at the flow rate Q1.
  • the horizontal-axis submersible pump 1 is operated in the full drainage mode.
  • the horizontal-axis submersible pump 1 When the water level further decreases and the discharge pressure decreases, the horizontal-axis submersible pump 1 operates in a state where the flap gate 9 is closed, that is, in an idling mode. At this time, the flow rate becomes zero and the power becomes P2. Generally, since the power of the axial flow vane increases when the flow rate is close to zero, it is desirable to set the mode so as to shift to the idling mode at a low water level where as much air as possible is sucked. Thereby, the horizontal-axis submersible pump 1 can perform an energy-saving operation with power P2 (P2 ⁇ P1) lower than the specification point power P1.
  • the start of air inflow is determined by the height of the front edge 13 of the suction cover 7 (or the lower end of the front wall 15). If the position of the leading edge 13 is high, air will quickly flow in from the opening 8 and a mixed state of air and water will occur, the head will be lowered, and it will not be possible to cope with an increase in the water level on the discharge side, and discharge at a low water level will not be possible. Further, the water in the casing 2 is likely to be scattered from the opening 8 to the suction side during the idling mode when the water level is lowered, and noise due to stirring in the casing 2 is generated.
  • the water level is reduced to the height of the front edge 13, and the operation is performed in the water-only drainage mode. Can be discharged immediately. Further, when the water level is lowered, the idling mode is set in accordance with the start of the inflow of air, and the operation is continued in a state where the water is maintained in the casing 2, so that the underwater electric motor 6 can be cooled.
  • the air flow starts at a position where the flap gate 9 does not open in the air / water mixture state, and the amount of water that can cool the submersible electric motor 6 is maintained at a level higher than the position at which the casing 2 can be maintained.
  • the front edge 13 of the suction cover 7 is set at this position. Specifically, as described above, the height position of the front edge 13 of the suction cover 7 is 10 to 25% above the impeller diameter ratio from the lower end of the impeller 3, and preferably 10 to 20% above.
  • FIG. 43 is a diagram for explaining the operation mode of the horizontal-axis submersible pump 1 in the present embodiment.
  • the horizontal axis submersible pump 1 has only two operation modes based on a preset water level L on the suction side, a full drainage mode M1 and an idling mode M3. Have In this case, the water level L is set to the height position of the leading edge 13.
  • FIG. 44 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level L). Even in this total drainage mode M1, the horizontal axis submersible pump 1 operates in the same manner as the full drainage mode M1 in the first embodiment shown in FIG.
  • FIG. 45 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level L ⁇ suction side water level). Even in the idling mode M3, the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
  • the same effects as those of the first embodiment are obtained.
  • the submersible electric motor 6 can be cooled even during operation in the idling mode. Therefore, the submersible electric motor 6 can maintain the operation at the rated rotational speed even in the idling mode, and can reduce the repetition frequency of the submersible electric motor 6, that is, the pump ON / OFF.
  • the horizontal-axis submersible pump 1 according to the present embodiment can employ three operation modes including the air / water mixed drainage mode M2 by combining with any of the above-described embodiments. Thereby, the horizontal-axis submersible pump 1 which concerns on this embodiment can also show
  • the upper wall 10 is inclined downward from the discharge side toward the suction side in each of the above embodiments, it may be horizontal.
  • the lower end (edge) of the side wall 11 is also inclined downward from the front edge or front wall side toward the discharge side in each of the above embodiments, but may be horizontal.
  • FIG. 46 is a two-side view illustrating the shape of the suction cover 7 in which the upper wall 10 is horizontal.
  • FIG. 47 is a two-side view illustrating the shape of the suction cover 7 in which the lower end 11a of the side wall 11 is horizontal.
  • the suction cover 7 shown in FIGS. 46 and 47 is a modification of the shape of the suction cover 7 shown in FIG.
  • the first to fifth embodiments are formed by forming an intake portion as the second suction opening at any position.
  • the operation mode can be set in the same manner as. For example, as shown in FIG. 46, when the suction hole 16 as the second suction opening is formed in the front wall 15 extending downward from the upper wall 10, the suction cover shown in FIG. It can be applied in the same manner as in the case of using 7.
  • an air intake portion as a second suction opening may be formed in the upper wall 10.
  • the water level corresponding to the height position of the upper wall 10, that is, the position where the second suction opening is formed is defined as H.
  • the idling mode M3 can be set for each side water level.
  • the side wall 11 shall be suspended from the both ends of the upper wall 10 in each said embodiment, if it is extended below, it will incline toward the outer side or the inner side of the suction cover 7.
  • the both end portions of the upper wall 10 here do not represent only exact ends, but positions shifted from both ends to the inside are allowed.
  • the shape of the front edge 13 of the upper wall 10 constituting the convex portion is an arc shape, but may be a mountain shape, for example.
  • the convex part here is not necessarily restricted to the shape started from the both ends of the front edge 13, A part of front edge 13 may comprise a convex part.
  • the number of convex portions may be plural.
  • FIG. 48 is a perspective view illustrating the shape of the suction cover 7 in which a part of the front edge 13 constitutes the convex portion 40.
  • the convex part 40 is formed in the center part of the front edge 13, and the shape is an arcuate shape.
  • FIG. 49 is a perspective view illustrating another shape of the suction cover 7 in which a part of the front edge 13 constitutes the convex portion 40.
  • the shape is a mountain shape.
  • FIG. 50 is a perspective view illustrating another shape of the suction cover 7 in which a part of the front edge 13 constitutes the convex portion 40.
  • FIG. 51 is a perspective view illustrating another shape of the suction cover 7.
  • a combination of edges of the front edge 13 of the upper wall 10 and the front edge 11b of the side wall 11 can be regarded as a convex portion. That is, both ends of the front edge 13 in this case correspond to the lower end of the front edge 11b.
  • the front wall 15 extends downward from the front edge 13 of the upper wall 10, but the front wall 15 does not necessarily extend from the front edge 13. It does not have to be extended.
  • FIG. 52 is a side cross-sectional view illustrating another shape of the suction cover 7.
  • the front wall 15 may extend downward from the inside of the upper wall 10 that is shifted downstream from the front edge 13.
  • the position where the front wall 15 is connected to the inside of the upper wall 10 is a position where the suction resistance that may be caused by the presence of the front wall 15 can be ignored. Therefore, if the distance from the end of the suction cover 7 on the side connected to the casing 2 to the front wall 15 is X and the diameter of the impeller 3 is D, the distance X is D to 1.5D or more. Is desirable. 52, the suction cover 7 shown in FIG. 3 and FIG.
  • the protrusion amounts of the upper wall 10 and the side wall 11 are not particularly limited as long as the effects described in the above embodiments are achieved.
  • the intake portion 14 that is the second suction opening is configured by a plurality of notches, and is generally saw-tooth or wave-shaped. There may be a case where only the notch is formed. However, it is advantageous to have a plurality of notches from the viewpoint of suppressing noise during intake.
  • Various shapes such as an arc shape, a mountain shape, or a convex shape can be applied to the shape of one notch.
  • the intake portion 14 constituted by a plurality of notches is formed on the front wall 15 is exemplified, but it may be formed on the upper wall 10. May be formed at the lower end (edge) of the side wall 11.
  • FIG. 53 is a perspective view showing the shape of the suction cover 7 in which a plurality of cutouts 41 as the intake portion 14 are provided on the upper wall 10.
  • FIG. 54 is a perspective view showing the shape of the suction cover 7 in which a plurality of cutouts 41 as the air intake portion 14 are provided at the lower end of the side wall 11.
  • the front wall 15 is suspended from the front edge 13 of the upper wall 10. It does not have to be done.
  • the front wall 15 may extend so as to incline toward the inside of the suction cover 7, or may be further connected to the upper wall 10 via a curved surface.
  • FIG. 55 is a perspective view showing the shape of the suction cover 7 in which the front wall 15 is inclined toward the inside of the suction cover 7 and connected to the upper wall 10 via a curved surface.
  • the suction cover 7 shown in FIG. 55 is assumed to be a modification of the shape of the suction cover 7 shown in FIG.
  • the opening to the internal space of the suction cover 7 can be achieved as compared with the case where the front wall 15 having a notch is suspended from the front edge 13 of the upper wall 10. Since the opening amount of the part 8 becomes narrow, it becomes difficult to leak noise to the outside. Therefore, particularly when the operation mode is the idling mode, noise can be further suppressed.
  • the tip of the suction cover 7 is rounded, dust flowing from the upstream side hardly adheres to the tip of the suction cover 7.
  • the shapes of the various suction covers 7 described above do not necessarily have to be adopted individually, and may be a shape combining the features.
  • the suction cover 7 may have both of the two types of intake portions 14 illustrated in FIGS. 53 and 54.
  • the pump body is installed in parallel to the water surface, that is, horizontally.
  • the pump main body here is synonymous with the main shaft 4 arrange
  • the present invention is not limited to a pump in which such a pump main body is installed horizontally, but can also be applied to a pump in which the pump main body is installed to be inclined downward on the suction side.
  • the casing 2 and the suction cover 7 are assumed to be separate bodies. This is advantageous in that the suction cover 7 can be easily replaced with another suction cover 7 when the suction cover 7 is damaged or when the suction cover 7 is changed to another shape according to the purpose.
  • this is not an essential configuration, and the casing 2 and the suction cover 7 may be integrated.
  • impeller 3 is supported so that it may be accommodated in the casing 2, as shown in FIG. 1, it is impeller by extending the main axis
  • Japanese Patent Application No. 2015-093983 (Application Date: May 1, 2015), Japanese Patent Application No. 2015-093984 (Application Date: May 1, 2015), Japanese Patent Application No. 2015-093985 (Application Date: May 2015) 1), Japanese Patent Application No. 2015-093986 (application date: May 1, 2015), Japanese Patent Application No. 2015-093987 (application date: May 1, 2015), Japanese Patent Application No. 2015-146260 (Application Date: The entire contents of July 24, 2015) are incorporated herein.

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Abstract

This horizontal shaft submersible pump includes: a casing having a suction port and a discharge port; an impeller supported in the casing; a suction cover connected to the suction port; a first suction opening which is provided in the suction cover and is open at a position below the upper end of the impeller; and a second suction opening which is provided, upstream of the impeller, in at least one of the suction cover and the casing, and is open at a position above the upper end of the first suction opening.

Description

横軸水中ポンプ、及び、横軸水中ポンプに用いられる吸込カバーHorizontal axis submersible pump and suction cover used for horizontal axis submersible pump
　本開示は、暗渠内等に設置して雨水や下水等の圧送に用いられる内水排除設備としての横軸水中ポンプ、及び、横軸水中ポンプに用いられる吸込カバーに関する。 This disclosure relates to a horizontal axis submersible pump as an internal water drainage facility installed in a culvert or the like and used for pumping rainwater or sewage, and a suction cover used for a horizontal axis submersible pump.
　従来、雨水等の排水ポンプとして、ポンプ設備を着脱構造に改良して低水位型の横軸水中ポンプ（横軸軸流型の水中ポンプ）を採用する排水機場の建設が増加している。 Conventionally, as drainage pumps for rainwater, etc., the construction of drainage stations that adopt low-water level horizontal axis submersible pumps (horizontal axis axial flow type submersible pumps) by improving the pump equipment to a detachable structure is increasing.
　また、例えば本川と支川とが合流するような場所には、支川側に開閉ゲートを設置し、大雨などの増水時に開閉ゲートを閉じることで、本川側の水が支川に逆流するのを抑止している。その際、支川の上流から流れてくる水を強制排水するために、横軸水中ポンプを開閉ゲートに取り付けたポンプゲートが多く用いられている。そして、ポンプゲートには、大容量の排水を行うために横軸水中ポンプが使用されることが多い。特許文献１は、横軸水中ポンプに吸込ベルマウス（吸込カバー）を設けて、低水位まで排水可能としたポンプゲートを開示している。 For example, in places where the main river and tributaries meet, an open / close gate is installed on the tributary side, and the water on the main river side flows back into the tributary by closing the open / close gate when there is a heavy rain. Suppressed. At that time, in order to forcibly drain the water flowing from the upstream of the tributaries, a pump gate having a horizontal axis submersible pump attached to an open / close gate is often used. The pump gate often uses a horizontal axis submersible pump in order to discharge a large volume of water. Patent document 1 is disclosing the pump gate which provided the suction bell mouth (suction cover) in the horizontal axis submersible pump, and was able to drain to a low water level.
特開２００３－００３４５０号公報JP 2003-003450 A
　特許文献１に開示された横軸水中ポンプは、全量排水運転時のような、羽根車が完全に没水した状態での運転時の水位以下となると、空運転となって一旦停止し、その後、流入量が増大して水位が上昇したときに再起動される。このように水位に応じて頻繁にポンプのＯＮ／ＯＦＦが繰り返されると、運転管理が煩雑となり、起動頻度が頻繁となって水中電動機への負担が大きくなる。 When the horizontal axis submersible pump disclosed in Patent Document 1 falls below the water level during operation in a state where the impeller is completely submerged, such as during full drainage operation, it becomes idle operation and then stops. It is restarted when the inflow increases and the water level rises. When the pump is frequently turned on and off in accordance with the water level as described above, the operation management becomes complicated, the activation frequency becomes frequent, and the load on the submersible electric motor increases.
　そこで、本発明は、吸込側の水位が全量排水運転時の水位以下でも、定格回転数での運転を維持し、ポンプの停止と起動との繰り返しを抑えることが可能な横軸水中ポンプを提供することを目的とする。 Accordingly, the present invention provides a horizontal-axis submersible pump capable of maintaining operation at the rated rotation speed and suppressing repetition of stopping and starting of the pump even when the water level on the suction side is equal to or lower than the water level during drainage operation. The purpose is to do.
　本発明の一つの態様である横軸水中ポンプは、吸込口と排出口とを有するケーシングと、ケーシング内で支持された羽根車と、吸込口に接続された吸込カバーと、吸込カバーに設けられ、羽根車の上端よりも低い位置に開口する第１吸込開口と、吸込カバー及びケーシングのうち少なくとも一方において羽根車よりも上流側に設けられ、第１吸込開口の上端よりも高い位置に開口する第２吸込開口と、を有する。 A horizontal axis submersible pump according to one aspect of the present invention is provided in a casing having a suction port and a discharge port, an impeller supported in the casing, a suction cover connected to the suction port, and the suction cover. The first suction opening that opens at a position lower than the upper end of the impeller, and at least one of the suction cover and the casing are provided upstream of the impeller and open at a position higher than the upper end of the first suction opening. A second suction opening.
　これにより、横軸水中ポンプは、羽根車が完全に没水しない運転モードでも、空気を吸気しつつ運転するので、羽根車を駆動する水中電動機の定格回転数での運転を維持したまま、吸込側の水位の低下速度又は上昇速度を抑制することができる。したがって、水中電動機のＯＮ／ＯＦＦの繰り返し頻度を低下させることができる。 As a result, the horizontal-axis submersible pump operates while sucking in air even in the operation mode in which the impeller is not completely submerged, so that suction is performed while maintaining the operation at the rated rotational speed of the submersible motor that drives the impeller. The water level lowering speed or rising speed can be suppressed. Therefore, the repetition frequency of ON / OFF of the submersible electric motor can be reduced.
　また、吸込カバーは、上壁と、上壁から下方に延設される側壁と、を有し、上壁の前縁は、該前縁の両端部より高い位置を有し、第２吸込開口は、前縁と、該前縁の両端部を結ぶ直線とで囲まれた開口であるものとしてもよい。 The suction cover has an upper wall and a side wall extending downward from the upper wall, and the front edge of the upper wall has a position higher than both ends of the front edge, and the second suction opening May be an opening surrounded by a front edge and a straight line connecting both ends of the front edge.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
　また、吸込カバーは、上壁と、上壁から下方に延設される側壁と、上壁から下方に延設される前壁と、を有し、第２吸込開口は、前壁を貫通する孔であるものとしてもよい。 The suction cover has an upper wall, a side wall extending downward from the upper wall, and a front wall extending downward from the upper wall, and the second suction opening penetrates the front wall. It may be a hole.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。更に、吸込カバーは、上流側から向かってくる流体（水又は空気）を吸込カバー内に流入させることができる一方、流体に含まれる異物の吸込カバー内への流入を抑止できる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly. Furthermore, the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
　また、吸込カバーは、上壁と、上壁から下方に延設される側壁と、上壁から下方に延設される前壁と、を有し、第１吸込開口は、前壁の下端と、側壁の下端とで囲まれる開口であり、第２吸込開口は、第１吸込開口に連通し、前壁に形成された少なくとも１以上の切り欠きと、前壁の下端を結ぶ直線とで囲まれた開口であるものとしてもよい。 The suction cover has an upper wall, a side wall extending downward from the upper wall, and a front wall extending downward from the upper wall, and the first suction opening has a lower end of the front wall. The second suction opening is connected to the first suction opening and is surrounded by at least one notch formed in the front wall and a straight line connecting the lower end of the front wall. It may be an open opening.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。更に、吸込カバーは、上流側から向かってくる流体（水又は空気）を吸込カバー内に流入させることができる一方、流体に含まれる異物の吸込カバー内への流入を抑止できる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly. Furthermore, the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
　また、吸込カバーは、上壁と、上壁から下方に延設される側壁と、を有し、第１吸込開口は、上壁の前縁と、側壁の下端とで囲まれる開口であり、第２吸込開口は、第１吸込開口に連通し、上壁に形成された少なくとも１以上の切り欠きと、上壁の前縁を結ぶ直線とで囲まれた開口、又は、第１吸込開口に連通し、側壁に形成された少なくとも１以上の切り欠きと、側壁の下端を結ぶ直線とで囲まれた開口であるものとしてもよい。 The suction cover has an upper wall and a side wall extending downward from the upper wall, and the first suction opening is an opening surrounded by the front edge of the upper wall and the lower end of the side wall, The second suction opening communicates with the first suction opening, and is an opening surrounded by at least one notch formed in the upper wall and a straight line connecting the front edge of the upper wall, or the first suction opening. It is good also as an opening enclosed by the at least 1 or more notch formed in the side wall, and the straight line which connects the lower end of a side wall.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。更に、吸込カバーは、上流側から向かってくる流体（水又は空気）を吸込カバー内に流入させることができる一方、流体に含まれる異物の吸込カバー内への流入を抑止できる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly. Furthermore, the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
　また、吸込カバーは、上壁と、上壁から下方に延設される側壁と、を有し、第２吸込開口は、上壁又は側壁に形成された開口であるものとしてもよい。 The suction cover may have an upper wall and a side wall extending downward from the upper wall, and the second suction opening may be an opening formed in the upper wall or the side wall.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly.
　また、更に、一端が吸込カバー又はケーシングに接続され、他端が開放されている吸気口である吸気管を備え、吸込カバーは、上壁と、上壁から下方に延設される側壁と、を有し、第２吸込開口は、吸気口であるものとしてもよい。 Further, the intake pipe is an intake port having one end connected to the suction cover or the casing and the other end opened, and the suction cover includes an upper wall and a side wall extending downward from the upper wall; The second suction opening may be an intake port.
　これにより、全量排水の運転モードの水位以下での運転モードでも、吸込カバー内に好適に空気を流入させることができる。 Thus, air can be suitably introduced into the suction cover even in the operation mode below the water level of the operation mode of all drainage.
　また、吸込カバーの上壁の前縁、又は、吸込カバーの上壁から下方に延設される前壁の下端は、羽根車の下端から羽根車の直径比で１０～２５％上方に位置するものとしてもよい。 The front edge of the upper wall of the suction cover or the lower end of the front wall extending downward from the upper wall of the suction cover is located 10 to 25% above the impeller diameter ratio from the lower end of the impeller. It may be a thing.
　これにより、低水位時まで全量排水の運転モードでの運転が可能となり、特に全量排水の運転モードでは、空気吸込渦の発生をより好適に抑止することができる。 This makes it possible to operate in the drainage operation mode until the low water level, and in particular, in the drainage operation mode, it is possible to more suitably suppress the generation of air suction vortices.
　また、更に、ケーシングの排出口の側に設けられ、該排出口から排出される流体の圧力により開閉可能なフラップゲートを備えるものとしてもよい。 Furthermore, a flap gate that is provided on the side of the discharge port of the casing and that can be opened and closed by the pressure of the fluid discharged from the discharge port may be provided.
　これにより、全量排水及び気水混合排水の各運転モードでは、フラップゲートが常時開放され、各運転モードに応じた水を排出し、それ以下の水位時のアイドリングの運転モードでは、フラップゲートが閉塞されるので、ケーシング内で流体が循環流動しやすくなる。また、フラップゲートは、吐出圧により開閉するので、フラップゲートを開閉させる駆動装置や制御装置を別途設ける必要がなく、構成を簡素化することができる。 As a result, the flap gate is always open in each operation mode of total drainage and air / water mixture drainage, and water corresponding to each operation mode is discharged, and in the idling operation mode at the lower water level, the flap gate is blocked. Therefore, the fluid easily circulates and flows in the casing. Further, since the flap gate is opened and closed by the discharge pressure, it is not necessary to separately provide a driving device and a control device for opening and closing the flap gate, and the configuration can be simplified.
　また、更に、ケーシングの内圧が所定の圧力に達したときにケーシング内の空気を外部に排出するエア抜機構を備えるものとしてもよい。 Furthermore, an air venting mechanism for discharging the air in the casing to the outside when the internal pressure of the casing reaches a predetermined pressure may be provided.
　これにより、例えば、アイドリングの運転モード又は気水混合排水の運転モードから水位が上昇して別の運転モードに移行する際に、ケーシング内に滞留していた空気を好適に排出することができるので、水中電動機にかかる負荷を抑えることができる。 As a result, for example, when the water level rises from the idling operation mode or the air / water mixed drainage operation mode and shifts to another operation mode, the air remaining in the casing can be suitably discharged. The load on the submersible electric motor can be suppressed.
　また、本発明の一つの態様である横軸水中ポンプに用いられる吸込カバーは、排出開口と、上壁と、上壁から下方に延設される側壁と、上壁から下方に延設される前壁と、前壁の下端と側壁の下端とで囲まれる第１吸込開口と、第１吸込開口に連通し、前壁に形成された少なくとも１以上の切り欠きと、前壁の下端を結ぶ直線とで囲まれた開口である第２吸込開口と、を有する。 The suction cover used in the horizontal-axis submersible pump according to one aspect of the present invention includes a discharge opening, an upper wall, a side wall extending downward from the upper wall, and a lower side extending from the upper wall. The front wall, the first suction opening surrounded by the lower end of the front wall and the lower end of the side wall, and the at least one notch formed in the front wall that communicates with the first suction opening and connects the lower end of the front wall And a second suction opening that is an opening surrounded by a straight line.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。更に、吸込カバーは、上流側から向かってくる流体（水又は空気）を吸込カバー内に流入させることができる一方、流体に含まれる異物の吸込カバー内への流入を抑止できる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly. Furthermore, the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
　更に、本発明の他の態様である横軸水中ポンプに用いられる吸込カバーは、排出開口と、上壁と、上壁から下方に延設される側壁と、上壁の前縁と側壁の下端とで囲まれる第１吸込開口と、第１吸込開口に連通し、上壁に形成された少なくとも１以上の切り欠きと、上壁の前縁を結ぶ直線とで囲まれた開口、又は、第１吸込開口に連通し、側壁に形成された少なくとも１以上の切り欠きと、側壁の下端を結ぶ直線とで囲まれた開口である第２吸込開口と、を有する。 Furthermore, the suction cover used in the horizontal-axis submersible pump according to another aspect of the present invention includes a discharge opening, an upper wall, a side wall extending downward from the upper wall, a front edge of the upper wall, and a lower end of the side wall. An opening surrounded by a first suction opening, a first suction opening, at least one notch formed in the upper wall, and a straight line connecting the front edge of the upper wall; The first suction opening has at least one notch formed in the side wall and a second suction opening that is an opening surrounded by a straight line connecting the lower ends of the side walls.
　これにより、吸込カバーは、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、例えば、吸込側の水位が低下し、全量排水の運転モードの水位から気水混合排水の運転モードの水位になると、第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、滑らかに各運転モード間を移行させることができる。更に、吸込カバーは、上流側から向かってくる流体（水又は空気）を吸込カバー内に流入させることができる一方、流体に含まれる異物の吸込カバー内への流入を抑止できる。 This allows the suction cover to suppress the generation of air suction vortices from the water surface, thereby suppressing vibration and noise. In addition, for example, when the water level on the suction side decreases and the water level in the operation mode of the mixed water drainage is changed from the water level in the operation mode of the total drainage, the intake area at the second suction opening increases, so the air suction amount is reduced. It can increase suitably and can be changed between each operation mode smoothly. Furthermore, the suction cover can flow the fluid (water or air) coming from the upstream side into the suction cover, while suppressing the inflow of foreign matter contained in the fluid into the suction cover.
　本発明によれば、吸込側の水位が全量排水運転時の水位以下でも、定格回転数での運転を維持し、ポンプの停止と起動との繰り返しを抑えることが可能な横軸水中ポンプを提供することができる。 According to the present invention, there is provided a horizontal-axis submersible pump capable of maintaining operation at the rated rotational speed and suppressing repetition of stopping and starting of the pump even when the water level on the suction side is equal to or lower than the water level during drainage operation. can do.
図１は、本発明の実施形態に係る横軸水中ポンプの構成を示す図である。FIG. 1 is a diagram showing a configuration of a horizontal-axis submersible pump according to an embodiment of the present invention. 図２は、第１実施形態における吸込カバーの形状を示す図である。FIG. 2 is a view showing the shape of the suction cover in the first embodiment. 図３は、第１実施形態における吸込カバーの他の形状を示す図である。FIG. 3 is a view showing another shape of the suction cover in the first embodiment. 図４は、第１実施形態における吸込カバーの他の形状を示す図である。FIG. 4 is a diagram illustrating another shape of the suction cover according to the first embodiment. 図５は、横軸水中ポンプを用いたポンプゲートシステムの構成を示す図である。FIG. 5 is a diagram showing a configuration of a pump gate system using a horizontal-axis submersible pump. 図６は、第１実施形態に係る横軸水中ポンプの運転モードを説明する図である。FIG. 6 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the first embodiment. 図７は、第１実施形態での全量排水モード時のポンプ動作を示す図である。FIG. 7 is a diagram illustrating a pump operation in the full drainage mode in the first embodiment. 図８は、第１実施形態での気水混合排出モード時のポンプ動作を示す図である。FIG. 8 is a diagram showing a pump operation in the air / water mixed discharge mode in the first embodiment. 図９は、第１実施形態でのアイドリングモード時のポンプ動作を示す図である。FIG. 9 is a diagram illustrating the pump operation in the idling mode in the first embodiment. 図１０は、横軸水中ポンプに設置されたエア抜機構の構成を示す図である。FIG. 10 is a diagram showing a configuration of an air bleeding mechanism installed in the horizontal-axis submersible pump. 図１１は、第２実施形態における吸込カバーの形状を示す図である。FIG. 11 is a diagram illustrating the shape of the suction cover according to the second embodiment. 図１２は、第２実施形態における吸気部の形状を示す図である。FIG. 12 is a diagram showing the shape of the intake section in the second embodiment. 図１３は、第２実施形態における吸気部の他の形状を示す図である。FIG. 13 is a diagram showing another shape of the intake section in the second embodiment. 図１４Ａは、第２実施形態における吸気部の他の形状を示す図である。FIG. 14A is a diagram illustrating another shape of the intake section in the second embodiment. 図１４Ｂは、第２実施形態における吸気部の他の形状を示す図である。FIG. 14B is a diagram showing another shape of the intake section in the second embodiment. 図１５は、第２実施形態における吸気部の他の形状を示す図である。FIG. 15 is a view showing another shape of the intake section in the second embodiment. 図１６は、第２実施形態に係る横軸水中ポンプの運転モードを説明する図である。FIG. 16 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the second embodiment. 図１７は、第２実施形態での全量排水モード時のポンプ動作を示す図である。FIG. 17 is a diagram illustrating a pump operation in the full-drainage mode in the second embodiment. 図１８は、第２実施形態での気水混合排出モード時のポンプ動作を示す図である。FIG. 18 is a diagram illustrating a pump operation in the air / water mixture discharge mode according to the second embodiment. 図１９は、第２実施形態でのアイドリングモード時のポンプ動作を示す図である。FIG. 19 is a diagram illustrating a pump operation in the idling mode in the second embodiment. 図２０は、第３実施形態に係る横軸水中ポンプの外形を示す図である。FIG. 20 is a diagram illustrating an outer shape of a horizontal-axis submersible pump according to the third embodiment. 図２１は、第３実施形態に係る横軸水中ポンプの他の外形を示す図である。FIG. 21 is a diagram showing another external shape of the horizontal-axis submersible pump according to the third embodiment. 図２２は、第３実施形態に係る横軸水中ポンプの運転モードを説明する図である。FIG. 22 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the third embodiment. 図２３は、第３実施形態での全量排水モード時のポンプ動作を示す図である。FIG. 23 is a diagram illustrating a pump operation in the full drainage mode in the third embodiment. 図２４は、第３実施形態での気水混合排出モード時のポンプ動作を示す図である。FIG. 24 is a diagram illustrating a pump operation in the air / water mixture discharge mode according to the third embodiment. 図２５は、第３実施形態でのアイドリングモード時のポンプ動作を示す図である。FIG. 25 is a diagram illustrating a pump operation in the idling mode in the third embodiment. 図２６は、第４実施形態における横軸水中ポンプの外形を示す図である。FIG. 26 is a diagram illustrating an outer shape of a horizontal-axis submersible pump in the fourth embodiment. 図２７は、第４実施形態における横軸水中ポンプの他の外形を示す図である。FIG. 27 is a diagram showing another external shape of the horizontal-axis submersible pump in the fourth embodiment. 図２８は、第４実施形態における横軸水中ポンプの他の外形を示す図である。FIG. 28 is a diagram showing another external shape of the horizontal-axis submersible pump in the fourth embodiment. 図２９は、第４実施形態に係る横軸水中ポンプの運転モードを説明する図である。FIG. 29 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the fourth embodiment. 図３０は、第４実施形態での全量排水モード時のポンプ動作を示す図である。FIG. 30 is a diagram illustrating a pump operation in the full-volume drainage mode according to the fourth embodiment. 図３１は、第４実施形態での気水混合排出モード時のポンプ動作を示す図である。FIG. 31 is a diagram illustrating a pump operation in the air / water mixed discharge mode according to the fourth embodiment. 図３２は、第４実施形態でのアイドリングモード時のポンプ動作を示す図である。FIG. 32 is a diagram illustrating a pump operation in the idling mode in the fourth embodiment. 図３３は、第５実施形態における横軸水中ポンプの外形を示す図である。FIG. 33 is a diagram showing an outer shape of a horizontal-axis submersible pump in the fifth embodiment. 図３４Ａは、第５実施形態における空気調整機構の構成を示す図である。FIG. 34A is a diagram illustrating a configuration of an air adjustment mechanism in the fifth embodiment. 図３４Ｂは、第５実施形態における空気調整機構の他の構成を示す図である。FIG. 34B is a diagram showing another configuration of the air adjustment mechanism in the fifth embodiment. 図３５は、第５実施形態に係る横軸水中ポンプの運転モードを説明する図である。FIG. 35 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the fifth embodiment. 図３６は、第５実施形態での全量排水モード時のポンプ動作を示す図である。FIG. 36 is a diagram illustrating a pump operation in the full-volume drainage mode according to the fifth embodiment. 図３７は、第５実施形態での気水混合排出モード時のポンプ動作を示す図である。FIG. 37 is a diagram showing a pump operation in the air / water mixture discharge mode according to the fifth embodiment. 図３８は、第５実施形態でのアイドリングモード時のポンプ動作を示す図である。FIG. 38 is a diagram illustrating a pump operation in the idling mode in the fifth embodiment. 図３９は、第６実施形態における横軸水中ポンプの構成を示す図である。FIG. 39 is a diagram showing a configuration of a horizontal-axis submersible pump in the sixth embodiment. 図４０Ａは、羽根車の要部正面図である。FIG. 40A is a front view of main parts of the impeller. 図４０Ｂは、吸込カバーの前縁の高さ位置における羽根車の展開図である。FIG. 40B is a development view of the impeller at the height position of the front edge of the suction cover. 図４１は、第６実施形態における吸込カバーの形状を示す図である。FIG. 41 is a diagram illustrating the shape of the suction cover according to the sixth embodiment. 図４２は、横軸水中ポンプの性能曲線を表すグラフである。FIG. 42 is a graph showing the performance curve of the horizontal axis submersible pump. 図４３は、第６実施形態に係る横軸水中ポンプの運転モードを説明する図である。FIG. 43 is a diagram for explaining an operation mode of the horizontal-axis submersible pump according to the sixth embodiment. 図４４は、第６実施形態での全量排水モード時のポンプ動作を示す図である。FIG. 44 is a diagram illustrating a pump operation in the total amount draining mode in the sixth embodiment. 図４５は、第６実施形態でのアイドリングモード時のポンプ動作を示す図である。FIG. 45 is a diagram showing a pump operation in the idling mode in the sixth embodiment. 図４６は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 46 is a view showing the shape of a suction cover as another embodiment. 図４７は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 47 is a view showing the shape of a suction cover as another embodiment. 図４８は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 48 is a view showing the shape of a suction cover as another embodiment. 図４９は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 49 is a diagram showing the shape of a suction cover as another embodiment. 図５０は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 50 is a diagram illustrating a shape of a suction cover as another embodiment. 図５１は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 51 is a diagram illustrating a shape of a suction cover as another embodiment. 図５２は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 52 is a view showing the shape of a suction cover as another embodiment. 図５３は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 53 is a view showing the shape of a suction cover as another embodiment. 図５４は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 54 is a view showing the shape of a suction cover as another embodiment. 図５５は、他の実施形態としての吸込カバーの形状を示す図である。FIG. 55 is a diagram showing the shape of a suction cover as another embodiment.
（第１実施形態）
　図１は、本発明の第１実施形態に係る横軸水中ポンプ１の構成を示す側断面図である。横軸水中ポンプ１は、大容量の排水を行うことが可能な横軸軸流型の水中ポンプであり、ケーシング２と、羽根車３と、主軸４と、案内羽根５と、水中電動機６とを備える。 (First embodiment)
FIG. 1 is a side sectional view showing a configuration of a horizontal-axis submersible pump 1 according to a first embodiment of the present invention. The horizontal axis submersible pump 1 is a horizontal axis axial flow type submersible pump capable of discharging a large volume of water, and includes a casing 2, an impeller 3, a main shaft 4, guide vanes 5, and an underwater electric motor 6. Is provided.
　ケーシング２は、吸込口と排出口とを有する筒体であり、その内部を流体（水及び空気）が通過する。ケーシング２の内部には、吸込側から、羽根車３、案内羽根５及び水中電動機６が配置される。羽根車３は、排水機場の仕様に応じて選択されるものであり、例えば、軸流羽根又は斜流羽根である。主軸４は、水中電動機６で発生された回転力を羽根車３に伝達するものであり、一端が水中電動機６に接続され、他端が羽根車３に接続される。すなわち、羽根車３は、ケーシング２に保持されている水中電動機６により、主軸４を介して支持されている。案内羽根５は、ケーシング２内を流通する流体の流れ方向を規定する。 The casing 2 is a cylinder having a suction port and a discharge port, and fluid (water and air) passes through the inside thereof. Inside the casing 2, an impeller 3, a guide blade 5 and an underwater electric motor 6 are arranged from the suction side. The impeller 3 is selected according to the specifications of the drainage station, and is, for example, an axial flow blade or a mixed flow blade. The main shaft 4 transmits the rotational force generated by the submersible electric motor 6 to the impeller 3, and one end is connected to the submersible electric motor 6 and the other end is connected to the impeller 3. That is, the impeller 3 is supported via the main shaft 4 by the underwater motor 6 held in the casing 2. The guide vanes 5 define the flow direction of the fluid flowing through the casing 2.
　更に、横軸水中ポンプ１は、ケーシング２の吐出側に開閉可能に支持されたフラップゲート９を備え得る。なお、フラップゲート９は、ケーシング２の排出口に直接的又は間接的に設けられ得る。例えば、ケーシング２とフラップゲート９とは、横軸水中ポンプ１の被取り付け対象である水門壁を介して互いに接続されてもよい。ここで、水門壁の一例としては、後述するようなポンプゲートシステムのゲート扉体が挙げられる。フラップゲート９は、横軸水中ポンプ１の吐出圧力が低いときには自重により閉じ、吐出圧力が高いときには上部の支点を軸として開くことで排水を可能とする。なお、用途に応じては、ケーシング２の吐出側に吐出配管を接続して排水することも可能である。 Furthermore, the horizontal-axis submersible pump 1 may be provided with a flap gate 9 supported on the discharge side of the casing 2 so as to be opened and closed. The flap gate 9 can be provided directly or indirectly at the outlet of the casing 2. For example, the casing 2 and the flap gate 9 may be connected to each other through a sluice wall to which the horizontal axis submersible pump 1 is attached. Here, as an example of the sluice wall, there is a gate door body of a pump gate system as described later. The flap gate 9 is closed by its own weight when the discharge pressure of the horizontal-axis submersible pump 1 is low, and allows drainage by opening around the upper fulcrum when the discharge pressure is high. Depending on the application, it is also possible to connect the discharge pipe to the discharge side of the casing 2 and drain the water.
　また、横軸水中ポンプ１は、ケーシング２の吸込側に、開口部８を下方に向けた吸込カバー７を備える。吸込カバー７は、例えば鋳物製であり、開口部８から吸い込んだ流体をケーシング２の吸込口に導く。 Also, the horizontal axis submersible pump 1 is provided with a suction cover 7 on the suction side of the casing 2 with the opening 8 facing downward. The suction cover 7 is made of, for example, a casting, and guides the fluid sucked from the opening 8 to the suction port of the casing 2.
　図２は、本実施形態における吸込カバー７の形状を示す三面図である。吸込カバー７は、上壁１０と、上壁１０の両側端からそれぞれ下方に延設される２つの側壁１１と、ケーシング２に接続し、排出開口を有するフランジ１２とを有する。上壁１０は、吸込側（側面図の左方向）に向かって下方に傾斜している。側壁１１の下端は、上壁１０の前縁１３の両端から横軸水中ポンプ１のケーシング２下方近傍までそれぞれ傾斜している。 FIG. 2 is a three-side view showing the shape of the suction cover 7 in the present embodiment. The suction cover 7 includes an upper wall 10, two side walls 11 extending downward from both ends of the upper wall 10, and a flange 12 connected to the casing 2 and having a discharge opening. The upper wall 10 is inclined downward toward the suction side (left direction in the side view). The lower end of the side wall 11 is inclined from both ends of the front edge 13 of the upper wall 10 to the vicinity of the lower part of the casing 2 of the horizontal axis submersible pump 1.
　吸込カバー７の開口部８は、吸込側の方が他の側よりも高くなるように傾いた状態で設けられている、本実施形態における第１吸込開口である。上壁１０の前縁１３は、中央部分が両端部より高い凸部を形成している。そして、吸込カバー７の吸気部１４は、前縁１３の両端部を結ぶ直線（２点鎖線）と凸形の前縁１３とで囲まれた空間であり、本実施形態における第２吸込開口である。なお、前縁１３は、一直線に限らず、前縁１３の中央部分が吸込側に突出していてもよい。また、吸気部１４の最も高い位置にある始端１４ａと、最も低い位置にある終端１４ｂとは、排水機場や横軸水中ポンプ１の仕様に応じて、後述する気水混合排出モードで運転可能な位置に設定される。 The opening 8 of the suction cover 7 is a first suction opening in the present embodiment, which is provided in an inclined state so that the suction side is higher than the other side. The front edge 13 of the upper wall 10 forms a convex portion whose central portion is higher than both end portions. The suction portion 14 of the suction cover 7 is a space surrounded by a straight line (two-dot chain line) connecting both end portions of the front edge 13 and the convex front edge 13, and is a second suction opening in the present embodiment. is there. The front edge 13 is not limited to a straight line, and the central portion of the front edge 13 may protrude toward the suction side. In addition, the start end 14a at the highest position of the intake section 14 and the end end 14b at the lowest position can be operated in an air-water mixed discharge mode, which will be described later, according to the specifications of the drainage pump station and the horizontal axis submersible pump 1. Set to position.
　図３は、本実施形態における吸込カバー７の他の形状を示す二面図である。本実施形態において、吸込カバー７の形状は、図２に示すようなものに限定されず、図３に示すようなものであってもよい。図３に示す吸込カバー７は、上壁１０の前縁１３から下方に向かって延設される前壁１５を有する。この場合、本実施形態における第２吸込開口は、前壁１５を貫通する複数の吸気孔１６である。側壁１１の下端（端部）は、前壁１５の下端からフランジ１２に向かって所定の傾斜角度を有する。前壁１５の延設長さは、後述する気水混合排出モードやアイドリングモードの運転状況により適宜設定される。また、吸気孔１６の形状は、円状、長孔状、スリット状等、適宜選択可能であり、吸気孔１６の孔径やスリットの幅なども、運転条件に応じて適宜決定される。 FIG. 3 is a two-side view showing another shape of the suction cover 7 in the present embodiment. In the present embodiment, the shape of the suction cover 7 is not limited to that shown in FIG. 2, but may be as shown in FIG. The suction cover 7 shown in FIG. 3 has a front wall 15 extending downward from the front edge 13 of the upper wall 10. In this case, the second suction opening in the present embodiment is a plurality of intake holes 16 penetrating the front wall 15. The lower end (end portion) of the side wall 11 has a predetermined inclination angle from the lower end of the front wall 15 toward the flange 12. The extending length of the front wall 15 is appropriately set according to the operation status of the air / water mixed discharge mode and idling mode described later. In addition, the shape of the intake hole 16 can be appropriately selected from a circular shape, a long hole shape, a slit shape, and the like, and the hole diameter of the intake hole 16 and the width of the slit are also appropriately determined according to the operating conditions.
　図４は、本実施形態における吸込カバー７の他の形状を示す二面図である。図４に示す吸込カバー７は、上壁１０の前縁１３を水平とし、前縁１３から下方に向かって延設される前壁１５を有する。前壁１５は、開口部８に連通する、少なくとも１以上の切り欠きを有し、これらの切り欠きを全体として見ると、その形状は、鋸状又は波状である。この場合、本実施形態における第２吸込開口は、切り欠きと、前壁１５の下端を結ぶ直線（２点鎖線）とで囲まれる開口としての吸気部１４である。側壁１１の形状や、前壁１５の延設長さについては、図３に示す吸込カバー７と同様である。 FIG. 4 is a two-side view showing another shape of the suction cover 7 in the present embodiment. The suction cover 7 shown in FIG. 4 has a front wall 15 that has the front edge 13 of the upper wall 10 horizontal and extends downward from the front edge 13. The front wall 15 has at least one or more cutouts communicating with the opening 8, and when viewed as a whole, the cutout has a saw shape or a wave shape. In this case, the second suction opening in the present embodiment is an intake portion 14 as an opening surrounded by a notch and a straight line (two-dot chain line) connecting the lower ends of the front wall 15. The shape of the side wall 11 and the extension length of the front wall 15 are the same as those of the suction cover 7 shown in FIG.
　図５は、横軸水中ポンプ１を用いたポンプゲートシステム１７の構成を示す概略図である。ポンプゲートシステム１７は、ポンプゲート１９と、天壁２０から垂下し、ゲート扉体１８を吊り上げるラック棒２１と、ラック棒２１を上下動させることでポンプゲート１９を昇降させる開閉機２２とを備える。 FIG. 5 is a schematic diagram showing a configuration of a pump gate system 17 using the horizontal axis submersible pump 1. The pump gate system 17 includes a pump gate 19, a rack bar 21 that hangs down from the top wall 20 and lifts the gate door 18, and an opening / closing device 22 that moves the rack bar 21 up and down to raise and lower the pump gate 19. .
　ポンプゲート１９は、ゲート扉体１８に横軸水中ポンプ１を着脱自在に組み込み、河川等の水路を開閉するものであり、上流側（図左方）から下流側（図右方）へ水を排水する。具体的には、平時は、ゲート扉体１８を上昇させた状態で、ポンプ吸込側（上流側）の水路の水をポンプ吐出側（下流側）の水路に自然排水する。一方、大雨等で下流側の外水位が上昇した際には、開閉機２２の駆動によりゲート扉体１８を下降させて水路を閉じ、横軸水中ポンプ１は、上流側の水を下流側に強制的に排水する。なお、本実施形態におけるポンプゲートシステム１７は、ポンプゲート１９を垂直に降下させて水路を閉止しているが、揺動又は回転等の公知技術により水路を閉止してもよい。 The pump gate 19 detachably installs the horizontal axis submersible pump 1 in the gate door body 18 and opens and closes a water channel such as a river. Water is supplied from the upstream side (left side in the figure) to the downstream side (right side in the figure). Drain. Specifically, during normal times, the water in the pump suction side (upstream side) water channel is naturally drained into the pump discharge side (downstream side) water channel with the gate door 18 raised. On the other hand, when the outside water level on the downstream side rises due to heavy rain or the like, the gate door 18 is lowered by driving the switch 22 to close the water channel, and the horizontal axis submersible pump 1 causes the upstream water to flow downstream. Force drain. In the pump gate system 17 according to the present embodiment, the pump gate 19 is vertically lowered to close the water channel, but the water channel may be closed by a known technique such as swinging or rotation.
　次に、ポンプゲートシステム１７に用いられる横軸水中ポンプ１の運転モードについて説明する。図６は、横軸水中ポンプ１の運転モードを説明する図である。なお、図６では、吸込カバー７の形状が図３に示すものであるとして説明するが、図２又は図４に示す吸込カバー７であっても同様である。 Next, the operation mode of the horizontal axis submersible pump 1 used for the pump gate system 17 will be described. FIG. 6 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1. 6 explains that the shape of the suction cover 7 is as shown in FIG. 3, the same applies to the suction cover 7 shown in FIG. 2 or FIG. 4.
　横軸水中ポンプ１は、予め設定された吸込側の２つの水位Ｈ，Ｍ（Ｈ＞Ｍ）を基準とした３つの運転モードを有する。具体的には、全量排水モードＭ１と、気水混合排出モードＭ２と、アイドリングモードＭ３とである。全量排水モードＭ１は、吸込側の水位が水位Ｈを超えているときに実施される。気水混合排出モードＭ２は、吸込側の水位が、水位Ｈ以下で、かつ、水位Ｍを超えているときに実施される。アイドリングモードＭ３は、吸込側の水位が水位Ｍ以下であるときに実施される。なお、不図示であるが、吸込側の水位が特定の水位Ｌ（Ｌ＜Ｍ）以下であるときは、横軸水中ポンプ１は、運転を停止する。 The horizontal axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M) on the suction side. Specifically, the total amount drainage mode M1, the air / water mixed discharge mode M2, and the idling mode M3 are performed. The full drainage mode M1 is performed when the water level on the suction side exceeds the water level H. The air / water mixture discharge mode M2 is performed when the water level on the suction side is equal to or lower than the water level H and exceeds the water level M. The idling mode M3 is performed when the water level on the suction side is equal to or lower than the water level M. Although not shown, when the water level on the suction side is equal to or lower than a specific water level L (L <M), the horizontal submersible pump 1 stops operation.
　吸込カバー７が図３に示す形状である場合、水位Ｈは、吸込カバー７の吸気孔１６の上端１６ａの位置に設定される。水位Ｍは、吸込カバー７の開口部８の上端に設定される。また、水位Ｌは、羽根車３が回転していても、水中電動機６に十分な水が供給できない水位の上限に設定される。なお、吸込カバー７が図２に示す形状である場合には、水位Ｈは、吸込カバー７の吸気部１４の始端１４ａの位置に設定され、水位Ｍは、吸気部１４の終端１４ｂの位置に設定される。 When the suction cover 7 has the shape shown in FIG. 3, the water level H is set at the position of the upper end 16 a of the suction hole 16 of the suction cover 7. The water level M is set at the upper end of the opening 8 of the suction cover 7. The water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating. When the suction cover 7 has the shape shown in FIG. 2, the water level H is set to the position of the start end 14 a of the intake portion 14 of the suction cover 7, and the water level M is set to the position of the end 14 b of the intake portion 14. Is set.
＜全量排水モード＞
　図７は、運転モードが全量排水モードＭ１（吸込側水位＞水位Ｈ）であるときの横軸水中ポンプ１の動作を説明する図である。全量排水モードＭ１は、上流側で吸い込んだ水を下流側に全量排出させる運転モードである。大雨等によりゲート下流側（吐出側）の水位が上昇すると、逆流を抑止するために、ゲート扉体１８が降下され、水路が閉止される。そして、ゲート上流側（吸込側）の水位が水位Ｈを越えると、横軸水中ポンプ１が起動され、横軸水中ポンプ１は、全量排水モードＭ１で、定格回転数で運転して下流側に排水する。このとき、横軸水中ポンプ１の内部に連通する開口（吸気孔１６及び開口部８）は全て没水しており、横軸水中ポンプ１の吐出圧力により吐出側のフラップゲート９は開放した状態となっている。ここで、横軸水中ポンプ１の運転開始のタイミングは、不図示の制御装置が、公知の水位計等により水位Ｈを超えていることを検知した上で判断してもよいし、実際に水位Ｈを検知することなく、予め設定された開始時間等に基づいて自動で判断してもよい。 <Full drainage mode>
FIG. 7 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 when the operation mode is the full drainage mode M1 (suction side water level> water level H). The total amount draining mode M1 is an operation mode in which the entire amount of water sucked on the upstream side is discharged downstream. When the water level on the gate downstream side (discharge side) rises due to heavy rain or the like, the gate door body 18 is lowered and the water channel is closed in order to prevent backflow. Then, when the water level on the upstream side of the gate (suction side) exceeds the water level H, the horizontal axis submersible pump 1 is activated, and the horizontal axis submersible pump 1 operates at the rated rotation speed in the full-volume drainage mode M1 to the downstream side. Drain. At this time, all the openings (intake holes 16 and openings 8) communicating with the inside of the horizontal axis submersible pump 1 are submerged, and the discharge side flap gate 9 is opened by the discharge pressure of the horizontal axis submersible pump 1. It has become. Here, the operation start timing of the horizontal axis submersible pump 1 may be determined after a control device (not shown) detects that the water level H has been exceeded by a known water level gauge or the like. You may determine automatically based on the preset start time etc., without detecting H.
＜気水混合排出モード＞
　図８は、運転モードが気水混合排出モードＭ２（水位Ｈ≧吸込側水位＞水位Ｍ）であるときの横軸水中ポンプ１の動作を説明する図である。横軸水中ポンプ１が全量排水モードＭ１でゲート上流側の貯留水を排水した結果、ゲート上流側の水位が徐々に低下して水位Ｈ以下になると、運転モードが気水混合排出モードＭ２に移行する。気水混合排出モードＭ２は、水とともに少量の空気を吸気しつつ、定格回転数での運転で排水を行う運転モードである。 <Air / water mixed discharge mode>
FIG. 8 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 when the operation mode is the air / water mixture discharge mode M2 (water level H ≧ suction side water level> water level M). When the horizontal axis submersible pump 1 drains the stored water on the upstream side of the gate in the total drainage mode M1, when the water level on the upstream side of the gate gradually decreases and falls below the water level H, the operation mode shifts to the air / water mixture discharge mode M2. To do. The air / water mixture discharge mode M2 is an operation mode in which drainage is performed by operation at the rated rotational speed while inhaling a small amount of air together with water.
　具体的な水位としては、吸込カバー７の吸気孔１６の一部又は全部が大気開放しているが、開口部８は没水している水位である。吸込カバー７の吸気孔１６の上端１６ａを水位Ｈに設定することにより、開口部８から水を吸い込みながら、吸気孔１６から空気を吸い込むことができる。排水量は、水位と吸気量との関係より決定される。この気水混合排出モードＭ２を設けることにより、低水位での不安定運転を緩和することができる。 As a specific water level, a part or all of the intake holes 16 of the suction cover 7 are open to the atmosphere, but the opening 8 is a submerged water level. By setting the upper end 16 a of the suction hole 16 of the suction cover 7 to the water level H, air can be sucked from the suction hole 16 while sucking water from the opening 8. The amount of drainage is determined from the relationship between the water level and the intake air amount. By providing this air / water mixed discharge mode M2, unstable operation at a low water level can be mitigated.
　なお、気水混合排出モードＭ２では、横軸水中ポンプ１の吐出圧力は、全量排水モードＭ１のときよりも低下している。ただし、フラップゲート９は、開放されたままである。 In addition, in the air / water mixed discharge mode M2, the discharge pressure of the horizontal axis submersible pump 1 is lower than that in the full discharge mode M1. However, the flap gate 9 remains open.
＜アイドリングモード＞
　図９は、運転モードがアイドリングモードＭ３（水位Ｍ≧吸込側水位＞水位Ｌ）であるときの横軸水中ポンプ１の動作を説明する図である。横軸水中ポンプ１が排水を続けることで、更に水位が低下して水位Ｍ以下になると、運転モードは、気水混合排出モードＭ２からアイドリングモードＭ３に移行する。アイドリングモードＭ３は、いわゆる待機運転となるモードであり、水とともに大量の空気を吸気しつつ、定格回転数での運転を維持する運転モードである。 <Idling mode>
FIG. 9 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 when the operation mode is the idling mode M3 (water level M ≧ suction side water level> water level L). When the horizontal axis submersible pump 1 continues draining and the water level is further lowered to become the water level M or less, the operation mode shifts from the air / water mixed discharge mode M2 to the idling mode M3. The idling mode M3 is a mode in which a so-called standby operation is performed, and is an operation mode in which operation at the rated rotational speed is maintained while a large amount of air is sucked together with water.
　具体的な水位としては、吸込カバー７の開口部８の一部が大気開放しているものの、羽根車３の一部が没水している水位である。吸込カバー７の開口部８の上端を水位Ｍに設定することにより、水位が水位Ｍ低下になったときに、吸込カバー７の吸気孔１６と開口部８とから大量の空気を吸い込むことができる。その結果、横軸水中ポンプ１の吐出圧力は低下するが、ケーシング２内で水と空気とが混合した状態で運転が継続される。ケーシング２内の水量は、吸込側水位に応じて変動する。このアイドリングモードＭ３では、ケーシング２内で攪拌される水により、水中電動機６が冷却されるため、過度の発熱を抑えることができる。 Specific water level is a level at which part of the opening 8 of the suction cover 7 is open to the atmosphere but part of the impeller 3 is submerged. By setting the upper end of the opening 8 of the suction cover 7 to the water level M, a large amount of air can be sucked from the intake hole 16 and the opening 8 of the suction cover 7 when the water level drops to the water level M. . As a result, the discharge pressure of the horizontal-axis submersible pump 1 decreases, but the operation is continued in a state where water and air are mixed in the casing 2. The amount of water in the casing 2 varies according to the suction side water level. In the idling mode M3, since the underwater electric motor 6 is cooled by the water stirred in the casing 2, excessive heat generation can be suppressed.
　なお、アイドリングモードＭ３では、水と空気とがケーシング２内で循環流動し、吐出圧力が低いため、フラップゲート９は、基本的には閉塞した状態にある。ただし、下流側の水位が低下すると、フラップゲート９が開放する場合もある。また、フラップゲート９を閉塞した締切状態で定格回転数での運転を行っても、大量の空気が混入しているため、水動力が低く、ポンプ動力の上昇を抑制することができる。 In the idling mode M3, since the water and air circulate and flow in the casing 2 and the discharge pressure is low, the flap gate 9 is basically in a closed state. However, when the downstream water level falls, the flap gate 9 may open. Further, even when the operation at the rated rotation speed is performed with the flap gate 9 closed, since a large amount of air is mixed, the hydraulic power is low and the pump power can be prevented from increasing.
　ここで、アイドリングモードＭ３では、基本的には水を排出しないので、吸込側の水位の低下はない。しかし、下流側の水位の低下により横軸水中ポンプ１の吐出圧力がフラップゲート９を開放するだけの圧力になると、排水により吸込側の水位が低下してくる。吸込側の水位が低下して水位Ｌ以下になると、横軸水中ポンプ１は、吸込側の流入予測量にもよるが、再排水の可能性が低いと判断して運転を停止する。横軸水中ポンプ１の運転停止のタイミングは、不図示の制御装置が、公知の水位計等により、水位Ｌ以下の水位を一定時間継続した状態を検知した上で判断してもよいし、実際に水位Ｌを検知することなく、予め設定された開始時間等に基づいて自動で判断してもよい。 Here, in the idling mode M3, since water is not basically discharged, there is no drop in the water level on the suction side. However, if the discharge pressure of the horizontal-axis submersible pump 1 becomes a pressure sufficient to open the flap gate 9 due to a decrease in the water level on the downstream side, the water level on the suction side decreases due to drainage. When the water level on the suction side decreases and becomes equal to or lower than the water level L, the horizontal axis submersible pump 1 determines that the possibility of re-drainage is low, depending on the estimated amount of inflow on the suction side, and stops operation. The timing of stopping the operation of the horizontal axis submersible pump 1 may be determined after a control device (not shown) detects a state in which the water level below the water level L continues for a certain period of time using a known water level gauge or the like. Alternatively, it may be automatically determined based on a preset start time without detecting the water level L.
　一方、いずれかの運転モード中に上流側の流入量が増大して水位が上昇したときも、別の運転モードに移行する。例えば、水位Ｌ以下の状態で水位が上昇し、吸込側の水位が水位Ｌを超えたとする。この場合、運転モードは、開口部８からは水と空気を、吸気孔１６からは空気を吸気しつつ、フラップゲート９を閉じた状態でケーシング２内の水を攪拌するアイドリングモードＭ３に移行する。また、アイドリングモードＭ３中に水位が上昇し、吸込側の水位が水位Ｍを超えると、運転モードは、開口部８からは水を、吸気孔１６からは空気を吸気しながら排水する気水混合排出モードＭ２に移行する。更に、気水混合排出モードＭ２中に水位が上昇し、吸込側の水位が水位Ｈを超えると、運転モードは、開口部８及び吸気孔１６から水を吸い込む全量排水モードＭ１に移行する。 On the other hand, when the upstream inflow increases and the water level rises during any of the operation modes, the operation mode is shifted to another operation mode. For example, it is assumed that the water level rises below the water level L and the water level on the suction side exceeds the water level L. In this case, the operation mode shifts to an idling mode M3 in which water and air are sucked from the opening 8 and air is sucked from the intake hole 16 and the water in the casing 2 is stirred while the flap gate 9 is closed. . Further, when the water level rises during the idling mode M3 and the water level on the suction side exceeds the water level M, the operation mode is an air-water mixture that drains water while sucking air from the opening 8 and sucking air from the intake hole 16. Transition to the discharge mode M2. Further, when the water level rises during the air / water mixture discharge mode M2 and the water level on the suction side exceeds the water level H, the operation mode shifts to the full-volume drainage mode M1 for sucking water from the opening 8 and the intake hole 16.
　なお、横軸水中ポンプ１は、運転停止後、吸込側の流入予測量や、排水機場又は横軸水中ポンプ１の仕様に応じて、運転再開を適宜判断する。運転再開のタイミングは、吸込側の水位がどの水位であっても構わない。 In addition, the horizontal axis submersible pump 1 appropriately determines whether to resume the operation according to the estimated amount of inflow on the suction side and the specifications of the drainage station or the horizontal axis submersible pump 1 after the operation is stopped. The timing of restarting operation may be any water level on the suction side.
　横軸水中ポンプ１は、更に、エア抜機構を備える。図１０は、横軸水中ポンプ１に設置されたエア抜機構２３の構成を示す概略図である。例えば、水位が上昇して、気水混合排出モードＭ２から全量排水モードＭ１に運転モードが移行する際には、ケーシング２内に滞留していた空気が、エア抜機構２３により外部に排出される。エア抜機構２３は、例えば、横軸水中ポンプ１の排出側に取り付けたフラップゲート９の上方に設置され得る、小さな開口を有するフラップ式のゲートである。ケーシング２内の水分の増大に伴い、内圧が所定の圧力に達すると、フラップ式のゲートが開放し、ケーシング２内のエアが外部に排出される。なお、エア抜機構２３は、ケーシング２内の水分の増大に伴い、内圧が所定の圧力に達すると自動的に作動する機構を備えたものであればよいもので、例えば、ケーシング２の上部に設置されるエア抜弁等であってもよい。 The horizontal axis submersible pump 1 further includes an air venting mechanism. FIG. 10 is a schematic diagram showing the configuration of the air vent mechanism 23 installed in the horizontal-axis submersible pump 1. For example, when the water level rises and the operation mode shifts from the air / water mixture discharge mode M2 to the full-volume drainage mode M1, the air staying in the casing 2 is discharged to the outside by the air vent mechanism 23. . The air vent mechanism 23 is, for example, a flap-type gate having a small opening that can be installed above the flap gate 9 attached to the discharge side of the horizontal-axis submersible pump 1. When the internal pressure reaches a predetermined pressure as the moisture in the casing 2 increases, the flap-type gate opens and the air in the casing 2 is discharged to the outside. The air venting mechanism 23 may be any mechanism provided with a mechanism that automatically operates when the internal pressure reaches a predetermined pressure as the moisture in the casing 2 increases. It may be an installed air vent valve or the like.
　次に、横軸水中ポンプ１の作用及び効果について説明する。横軸水中ポンプ１は、上記のように、第１吸込開口（開口部８）の上端よりも高い位置に開口する第２吸込開口（吸気部１４等）を有するので、吸込側の水位の変化に応じて運転モードを自動的に切り替えることができる。具体的には、横軸水中ポンプ１は、吸込側の水位が第２吸込開口の上端よりも高いときには、第１及び第２吸込開口を没水させて、全量排水モードで運転する。また、横軸水中ポンプ１は、吸込側の水位が、第２吸込開口の上端よりも低く、かつ、第１吸込開口の上端よりも高いときには、第１吸込開口から水を吸い込みつつ第２吸込開口から空気を吸い込む気水混合排水モードで運転を行う。更に、横軸水中ポンプ１は、吸込側の水位が第１吸込開口の上端よりも低いときには、第１及び第２吸込開口から空気を吸い込んでケーシング内で水を循環流動させるアイドリングモードで運転を行う。 Next, the operation and effect of the horizontal axis submersible pump 1 will be described. As described above, the horizontal-axis submersible pump 1 has the second suction opening (such as the intake section 14) that opens at a position higher than the upper end of the first suction opening (opening section 8), so that the water level on the suction side changes. The operation mode can be automatically switched according to the operation. Specifically, when the water level on the suction side is higher than the upper end of the second suction opening, the horizontal-axis submersible pump 1 is operated in the full drainage mode by immersing the first and second suction openings. Further, when the water level on the suction side is lower than the upper end of the second suction opening and higher than the upper end of the first suction opening, the horizontal-axis submersible pump 1 sucks water from the first suction opening while taking in the second suction. Operate in a mixed-air drainage mode that draws air from the opening. Further, when the water level on the suction side is lower than the upper end of the first suction opening, the horizontal-axis submersible pump 1 operates in an idling mode in which air is sucked from the first and second suction openings to circulate and flow water in the casing. Do.
　例えば、吸込側の水位が急速に低下した場合には、全量排水モードから気水混合排水モードへ、又は、気水混合排水モードからアイドリングモードへ移行する。これにより、横軸水中ポンプ１は、羽根車３を駆動する水中電動機６の定格回転数での運転を維持したまま、吸込側の水位の低下速度を抑制することができる。また、例えば、吸込側の水位が急速に上昇した場合には、アイドリングモードから気水混合排水モードへ、又は、気水混合排水モードから全量排水モードへ移行する。これにより、横軸水中ポンプ１は、水中電動機６の定格回転数での運転を維持したまま、吸込側の水位の上昇速度を抑制することができる。したがって、水中電動機６すなわちポンプのＯＮ／ＯＦＦの繰り返し頻度を低下させることができる。 For example, when the water level on the suction side drops rapidly, the whole volume drainage mode is switched to the air / water mixed drainage mode, or the air / water mixed drainage mode is shifted to the idling mode. Thereby, the horizontal-axis submersible pump 1 can suppress the rate of decrease in the water level on the suction side while maintaining the operation at the rated rotational speed of the submersible electric motor 6 that drives the impeller 3. Further, for example, when the water level on the suction side rises rapidly, the idling mode is switched to the air / water mixing / draining mode, or the air / water mixing / draining mode is shifted to the full amount draining mode. Thereby, the horizontal axis submersible pump 1 can suppress the rising speed of the water level on the suction side while maintaining the operation of the submersible electric motor 6 at the rated rotational speed. Therefore, the repetition frequency of ON / OFF of the underwater electric motor 6, that is, the pump can be reduced.
　また、羽根車３が完全に没水しない気水混合排水モード及びアイドリングモードの各運転モードでは、空気を吸気しつつ運転するので、羽根車３に大きな負圧がかからず、また、水面からの空気吸込渦を抑制することができる。 Further, in each operation mode of the air / water mixed drainage mode and idling mode in which the impeller 3 is not completely submerged, since the operation is performed while sucking air, the impeller 3 is not subjected to a large negative pressure, and from the water surface. The air suction vortex can be suppressed.
　更に、横軸水中ポンプ１は、水位に応じた各運転モード間の移行を、複雑な制御装置等を設けることなく実現することができる。 Furthermore, the horizontal axis submersible pump 1 can realize transition between the respective operation modes according to the water level without providing a complicated control device or the like.
　また、図２に示すような吸込カバー７によれば、水面からの空気吸込渦の発生を抑止して、振動・騒音を抑制することができる。また、気水混合排水モードでは、例えば、吸込側の水位の低下に伴って第２吸込開口での吸気面積が拡大するので、空気の吸込量を好適に増やし、また、各運転モード間を滑らかに移行させることができる。 Moreover, according to the suction cover 7 as shown in FIG. 2, generation | occurrence | production of the air suction vortex from the water surface can be suppressed, and a vibration and noise can be suppressed. Also, in the air / water mixed drainage mode, for example, the intake area at the second suction opening increases as the water level on the suction side decreases, so that the amount of air sucked in is suitably increased, and between each operation mode is smooth. Can be migrated to.
　さらに、図３又は図４に示すような吸込カバー７によれば、前壁１５に吸気孔１６又は吸気部１４を設けているので、前縁１３に沿って均一に空気が流入する。したがって、急激な空気の流入を抑え、振動・騒音を抑制できる。また、前壁１５に吸気孔１６等を設けることで、流入空気量の調整が容易になるとともに、異物の流入を抑止できる。 Further, according to the suction cover 7 as shown in FIG. 3 or FIG. 4, since the intake holes 16 or the intake portions 14 are provided in the front wall 15, air flows uniformly along the front edge 13. Therefore, rapid inflow of air can be suppressed, and vibration and noise can be suppressed. Further, by providing the front wall 15 with the intake holes 16 and the like, the adjustment of the inflow air amount can be facilitated and the inflow of foreign matter can be suppressed.
　以上のように、本実施形態によれば、吸込側の水位が全量排水運転時の水位以下でも、定格回転数での運転を維持し、ポンプの停止と起動との繰り返しを抑えることが可能な横軸水中ポンプを提供することができる。 As described above, according to the present embodiment, even when the water level on the suction side is equal to or lower than the water level at the time of drainage operation, it is possible to maintain operation at the rated rotational speed and suppress repetition of stopping and starting of the pump. A horizontal axis submersible pump can be provided.
（第２実施形態）
　次に、本発明の第２実施形態に係る横軸水中ポンプについて説明する。本実施形態に係る横軸水中ポンプでは、吸込カバー７の形状が、第１実施形態に係る横軸水中ポンプ１と異なる。以下、第１実施形態に係る横軸水中ポンプ１と同一部分には同一の符号を付して説明する。 (Second Embodiment)
Next, a horizontal axis submersible pump according to a second embodiment of the present invention will be described. In the horizontal axis submersible pump according to the present embodiment, the shape of the suction cover 7 is different from that of the horizontal axis submersible pump 1 according to the first embodiment. Hereinafter, the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
　図１１は、本実施形態における吸込カバー７の形状を示す三面図である。図２に示す第１実施形態における吸込カバー７と比較して、吸込カバー７の全体形状はほぼ同一であるが、吸気部１４の形状及び形成位置が異なる。 FIG. 11 is a three-side view showing the shape of the suction cover 7 in the present embodiment. Compared with the suction cover 7 in the first embodiment shown in FIG. 2, the overall shape of the suction cover 7 is substantially the same, but the shape and formation position of the intake portion 14 are different.
　図１２は、本実施形態における第２吸込開口の一例として、上壁１０に設けられた吸気部１４の形状を示す平面図である。吸気部１４は、所定の幅でフランジ１２近傍に位置する始端１４ａから前縁１３近傍に位置する終端１４ｂに向かって形成され、上壁１０の表面と裏面とを貫通する開口であり、水及び空気が流入自在である。なお、吸気部１４の開口による応力集中を軽減するために、各角を円弧状に形成してもよい。吸気部１４が没水している時は、吸気部１４からも吸水し、水位が低下してくると、空気が吸気部１４の始端１４ａ側から徐々に吸込カバー７内に流入する。特に本実施形態では、水位低下時に始端１４ａから終端１４ｂに向かって開口面積が増大するように、上壁１０の前縁１３側（吸気部１４の終端１４ｂ側）に幅を漸増させている。これにより、水位の低下に伴って滑らかに運転モードを移行させることができる。また、吸気部１４の始端１４ａ、終端１４ｂ及び幅は、上壁１０の傾斜角度やポンプ口径等の条件から適宜決定される。 FIG. 12 is a plan view showing the shape of the intake portion 14 provided on the upper wall 10 as an example of the second suction opening in the present embodiment. The intake portion 14 is formed from a start end 14a located near the flange 12 with a predetermined width toward an end end 14b located near the front edge 13, and is an opening penetrating the front surface and the back surface of the upper wall 10. Air can flow freely. In order to reduce stress concentration due to the opening of the intake portion 14, each corner may be formed in an arc shape. When the intake portion 14 is submerged, water is also absorbed from the intake portion 14, and when the water level is lowered, air gradually flows into the suction cover 7 from the start end 14 a side of the intake portion 14. In particular, in the present embodiment, the width is gradually increased toward the front edge 13 of the upper wall 10 (the end 14b side of the intake portion 14) so that the opening area increases from the start end 14a toward the end 14b when the water level decreases. Thereby, a driving | operation mode can be smoothly changed with the fall of a water level. Further, the start end 14a, the end end 14b and the width of the intake portion 14 are appropriately determined from conditions such as the inclination angle of the upper wall 10 and the pump diameter.
　図１３は、本実施形態における第２吸込開口の他の一例として、上壁１０に設けられた複数の吸気孔３０の形状を示す平面図である。複数の吸気孔３０の形成条件は、図１２に示す吸気部１４と同様の条件を満たす。また、吸気孔３０の孔径等も、ポンプの運転条件に応じて適宜決定される。 FIG. 13 is a plan view showing the shape of a plurality of intake holes 30 provided in the upper wall 10 as another example of the second suction opening in the present embodiment. The formation conditions of the plurality of intake holes 30 satisfy the same conditions as those of the intake portion 14 shown in FIG. Further, the diameter of the intake hole 30 and the like are appropriately determined according to the operating conditions of the pump.
　図１４Ａは、本実施形態における第２吸込開口の他の一例として、上壁１０に設けられた複数のスリット３２の形状を示す平面図であり、１つのスリット３２の形状が三角形で、かつ、そのようなスリット３２が複数、主軸４と平行となる方向に並んでいる例を示す。一方、図１４Ｂは、１つのスリット３２の形状が矩形で、かつ、そのようなスリット３２が複数、主軸４に対して垂直となる方向に並んでいる例を示す。複数のスリット３２の形成条件も、図１２に示す吸気部１４と同様の条件を満たす。また、スリット３２の幅等も、ポンプの運転条件に応じて適宜決定される。図１３及び図１４に示すように、吸気部１４に相当する部分を複数の開口で形成することにより、吸込カバー７の上壁１０の強度を保つことができ、吸込カバー７を薄板で構成することができる。 FIG. 14A is a plan view showing the shape of a plurality of slits 32 provided in the upper wall 10 as another example of the second suction opening in the present embodiment, and the shape of one slit 32 is triangular, and An example in which a plurality of such slits 32 are arranged in a direction parallel to the main shaft 4 is shown. On the other hand, FIG. 14B shows an example in which the shape of one slit 32 is rectangular and a plurality of such slits 32 are arranged in a direction perpendicular to the main shaft 4. The formation conditions of the plurality of slits 32 also satisfy the same conditions as those of the intake section 14 shown in FIG. Further, the width of the slit 32 and the like are appropriately determined according to the operating conditions of the pump. As shown in FIGS. 13 and 14, by forming a portion corresponding to the intake portion 14 with a plurality of openings, the strength of the upper wall 10 of the suction cover 7 can be maintained, and the suction cover 7 is formed of a thin plate. be able to.
　図１５は、本実施形態における第２吸込開口の他の一例として、側壁１１に設けられた吸気部１４の形状を示す側面図である。吸気部１４は、上部（水位が上昇する方向）に位置する始端１４ａから下部（水位が低下する方向）に位置する終端１４ｂに向かって、徐々に吸込側へ向かう幅が広くなるように形成され、側壁１１の表面と裏面とを貫通する開口であり、水及び空気が流入自在である。なお、吸気部１４の開口による応力集中を軽減するために、各角を円弧状に形成してもよい。吸気部１４が没水している時は、吸気部１４からも吸水し、水位が低下してくると、空気が吸気部１４の始端１４ａ側から徐々に吸込カバー７内に流入する。この場合も、水位低下時に始端１４ａから終端１４ｂに向かって開口面積が増大するように、側壁１１の下部側に幅を漸増させることで、水位の低下に伴って滑らかに運転モードを移行させることができる。なお、側壁１１に形成される吸気部１４は、上壁１０に形成される場合と同様に、多数の吸気孔３０や、複数のスリット３２等であってもよい。 FIG. 15 is a side view showing the shape of the intake portion 14 provided on the side wall 11 as another example of the second suction opening in the present embodiment. The intake portion 14 is formed so that the width toward the suction side gradually increases from the start end 14a located at the upper portion (the direction in which the water level rises) to the end end 14b located at the lower portion (the direction in which the water level decreases). This is an opening that penetrates the front and back surfaces of the side wall 11 and allows water and air to flow freely. In order to reduce stress concentration due to the opening of the intake portion 14, each corner may be formed in an arc shape. When the intake portion 14 is submerged, water is also absorbed from the intake portion 14, and when the water level is lowered, air gradually flows into the suction cover 7 from the start end 14 a side of the intake portion 14. Also in this case, by gradually increasing the width to the lower side of the side wall 11 so that the opening area increases from the start end 14a toward the end end 14b when the water level is lowered, the operation mode can be smoothly shifted as the water level is lowered. Can do. Note that the intake portion 14 formed in the side wall 11 may be a plurality of intake holes 30, a plurality of slits 32, and the like, as in the case of being formed in the upper wall 10.
　図１６は、本実施形態における横軸水中ポンプ１の運転モードを説明する図である。なお、図１６では、吸込カバー７の形状が図１２に示すものであるとして説明するが、図１３～図１５に示す吸込カバー７であっても同様である。横軸水中ポンプ１が、予め設定された吸込側の２つの水位Ｈ，Ｍ（Ｈ＞Ｍ）を基準とした３つの運転モード、全量排水モードＭ１、気水混合排出モードＭ２及びアイドリングモードＭ３を有する点は、第１実施形態と同様である。この場合、水位Ｈは、吸込カバー７の吸気部１４の始端１４ａの位置に設定される。水位Ｍは、前縁１３の頂部の位置に設定される。また、水位Ｌは、羽根車３が回転していても、水中電動機６に十分な水が供給できない水位の上限に設定される。 FIG. 16 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment. In FIG. 16, description is made assuming that the shape of the suction cover 7 is as shown in FIG. 12, but the same applies to the suction cover 7 shown in FIGS. The horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. The points are the same as in the first embodiment. In this case, the water level H is set at the position of the start end 14 a of the intake portion 14 of the suction cover 7. The water level M is set at the top position of the leading edge 13. The water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
　図１７は、運転モードが全量排水モードＭ１（吸込側水位＞水位Ｈ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この全量排水モードＭ１では、横軸水中ポンプ１は、図７に示した第１実施形態における全量排水モードＭ１と同様に動作する。 FIG. 17 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H). In this total amount draining mode M1, the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
　図１８は、運転モードが気水混合排出モードＭ２（水位Ｈ≧吸込側水位＞水位Ｍ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この気水混合排出モードＭ２では、横軸水中ポンプ１は、図８に示した第１実施形態における気水混合排出モードＭ２と同様に動作する。 FIG. 18 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ≧ suction side water level> water level M). In the air / water mixed discharge mode M2, the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
　図１９は、運転モードがアイドリングモードＭ３（水位Ｍ≧吸込側水位＞水位Ｌ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。このアイドリングモードＭ３では、横軸水中ポンプ１は、図９に示した第１実施形態におけるアイドリングモードＭ３と同様に動作する。 FIG. 19 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ≧ suction side water level> water level L). In the idling mode M3, the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
　このように、本実施形態によれば、第１実施形態と同様の効果を奏する。 Thus, according to the present embodiment, the same effects as in the first embodiment can be obtained.
（第３実施形態）
　次に、本発明の第３実施形態に係る横軸水中ポンプについて説明する。本実施形態に係る横軸水中ポンプでは、第２吸込開口としての吸気部１４が、吸込カバー７ではなくケーシング２に形成されている点が、第１及び第２実施形態に係る横軸水中ポンプ１と異なる。以下、第１実施形態に係る横軸水中ポンプ１と同一部分には同一の符号を付して説明する。 (Third embodiment)
Next, a horizontal axis submersible pump according to a third embodiment of the present invention will be described. In the horizontal-axis submersible pump according to the present embodiment, the horizontal-axis submersible pump according to the first and second embodiments is that the intake portion 14 as the second suction opening is formed not in the suction cover 7 but in the casing 2. Different from 1. Hereinafter, the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
　図２０は、本実施形態に係る横軸水中ポンプ１の外形を示す側断面図である。この場合、吸込カバー７の全体形状は、図２に示す第１実施形態における吸込カバー７とほぼ同一であるが、本実施形態における吸込カバー７には、吸気部１４が存在しない。一方、ケーシング２の側面のうち、上半分で、かつ、羽根車３の設置位置よりも上流側には、ケーシング２の外部と内部とを貫通する複数の吸気孔からなる吸気部１４が形成されている。複数の吸気孔は、筒状のケーシング２の頂部近傍の始端１４ａから、円周方向に沿ってケーシング２の筒幅中心近傍の終端１４ｂまで形成される。この場合の始端１４ａは、最も高水位に位置する吸気孔となり、終端１４ｂは、最も低水位に位置する吸気孔となる。図２０に示す例では、複数の吸気孔は、始端１４ａから終端１４ｂまで同じ数量（同じ開口面積）で並んでいる。ここでも、吸気部１４が没水しているときは、吸気部１４からも吸水し、水位が低下してくると、空気が吸気部１４の始端１４ａ側から徐々に吸込カバー７内に流入する。 FIG. 20 is a side sectional view showing the outer shape of the horizontal axis submersible pump 1 according to the present embodiment. In this case, the overall shape of the suction cover 7 is substantially the same as that of the suction cover 7 in the first embodiment shown in FIG. 2, but the suction portion 14 does not exist in the suction cover 7 in this embodiment. On the other hand, in the upper half of the side surface of the casing 2 and on the upstream side of the installation position of the impeller 3, an intake portion 14 including a plurality of intake holes penetrating the outside and the inside of the casing 2 is formed. ing. The plurality of intake holes are formed from the start end 14a near the top of the cylindrical casing 2 to the end 14b near the center of the cylinder width of the casing 2 along the circumferential direction. In this case, the start end 14a is an intake hole positioned at the highest water level, and the end end 14b is an intake hole positioned at the lowest water level. In the example shown in FIG. 20, the plurality of intake holes are arranged in the same quantity (the same opening area) from the start end 14a to the end end 14b. Also here, when the intake portion 14 is submerged, water is also absorbed from the intake portion 14, and when the water level decreases, air gradually flows into the suction cover 7 from the start end 14 a side of the intake portion 14. .
　図２１は、本実施形態に係る横軸水中ポンプ１の他の外形を示す平面図である。図２０に示すような吸気部１４を構成する複数の吸気孔を、図２１に示すように、水位低下時に始端１４ａから終端１４ｂに向かって開口面積が増大するように吸気孔の数量を増加させることで、水位の低下に伴って滑らかに運転モードを移行させることができる。 FIG. 21 is a plan view showing another external shape of the horizontal-axis submersible pump 1 according to the present embodiment. As shown in FIG. 21, the number of intake holes in the plurality of intake holes constituting the intake section 14 as shown in FIG. 20 is increased so that the opening area increases from the start end 14a toward the end end 14b when the water level decreases. As a result, the operation mode can be smoothly shifted as the water level decreases.
　なお、吸気部１４を構成する複数の吸気孔の形状は、円状に限らず、例えばスリット状でもよく、適宜選択可能である。また、吸気孔の孔径やスリットの幅等は、横軸水中ポンプ１の運転条件に応じて適宜決定される。更に、吸気部１４の始端１４ａ、終端１４ｂ及び幅は、機場や横軸水中ポンプ１の運転条件に応じて適宜決定される。 In addition, the shape of the plurality of intake holes constituting the intake portion 14 is not limited to a circular shape, and may be, for example, a slit shape and can be selected as appropriate. Further, the hole diameter of the intake hole, the width of the slit, and the like are appropriately determined according to the operating conditions of the horizontal axis submersible pump 1. Further, the start end 14a, the end end 14b and the width of the intake section 14 are appropriately determined according to the machine field and the operating conditions of the horizontal axis submersible pump 1.
　図２２は、本実施形態における横軸水中ポンプ１の運転モードを説明する図である。横軸水中ポンプ１が、予め設定された吸込側の２つの水位Ｈ，Ｍ（Ｈ＞Ｍ）を基準とした３つの運転モード、全量排水モードＭ１、気水混合排出モードＭ２及びアイドリングモードＭ３を有する点は、第１及び第２実施形態と同様である。この場合、水位Ｈは、ケーシング２の吸気部１４の始端１４ａの位置に設定される。水位Ｍは、前縁１３の頂部の位置に設定される。また、水位Ｌは、羽根車３が回転していても、水中電動機６に十分な水が供給できない水位の上限に設定される。 FIG. 22 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment. The horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. It has the same points as the first and second embodiments. In this case, the water level H is set at the position of the start end 14 a of the intake portion 14 of the casing 2. The water level M is set at the top position of the leading edge 13. The water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
　図２３は、運転モードが全量排水モードＭ１（吸込側水位＞水位Ｈ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この全量排水モードＭ１では、横軸水中ポンプ１は、図７に示した第１実施形態における全量排水モードＭ１と同様に動作する。 FIG. 23 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H). In this total amount draining mode M1, the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
　図２４は、運転モードが気水混合排出モードＭ２（水位Ｈ≧吸込側水位＞水位Ｍ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この気水混合排出モードＭ２では、横軸水中ポンプ１は、図８に示した第１実施形態における気水混合排出モードＭ２と同様に動作する。 FIG. 24 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ≧ suction side water level> water level M). In the air / water mixed discharge mode M2, the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
　図２５は、運転モードがアイドリングモードＭ３（水位Ｍ≧吸込側水位＞水位Ｌ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。このアイドリングモードＭ３では、横軸水中ポンプ１は、図９に示した第１実施形態におけるアイドリングモードＭ３と同様に動作する。 FIG. 25 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ≧ suction side water level> water level L). In the idling mode M3, the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
　このように、本実施形態によれば、第１実施形態と同様の効果を奏する。 Thus, according to the present embodiment, the same effects as in the first embodiment can be obtained.
（第４実施形態）
　次に、本発明の第４実施形態に係る横軸水中ポンプについて説明する。本実施形態に係る横軸水中ポンプは、一端が吸込カバー７又はケーシング２に接続され、他端が開放されている吸気口である吸気管を備え、他端の吸気口を第２吸込開口とする点が、第１～第３実施形態に係る横軸水中ポンプ１と異なる。以下、第１実施形態に係る横軸水中ポンプ１と同一部分には同一の符号を付して説明する。 (Fourth embodiment)
Next, a horizontal axis submersible pump according to a fourth embodiment of the present invention will be described. The horizontal-axis submersible pump according to the present embodiment includes an intake pipe that is an intake port having one end connected to the suction cover 7 or the casing 2 and the other end opened, and the other intake port is defined as a second suction opening. This is different from the horizontal axis submersible pump 1 according to the first to third embodiments. Hereinafter, the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
　図２６は、本実施形態に係る横軸水中ポンプ１の外形を示す側面図である。この場合、吸込カバー７の全体形状は、図２に示す第１実施形態における吸込カバー７とほぼ同一であるが、本実施形態における吸込カバー７には、吸気管１４が接続されている。具体的には、例えば、吸気管１４の一端は、吸込カバー７の側壁１１に接続され、吸込カバー７の内部に連通する。吸気管１４は、所定の長さだけ上方に延設されて、逆Ｕ字状に曲管される。そして、吸気管１４の他端は、下方に向けて吸気口１４ａとして開放される。この構成によれば、吸気口１４ａから一旦上方へ向かって吸引するので、水面の浮遊物により吸気口１４ａ及び管内が閉塞することが抑えられる。なお、他端を閉塞し、吸気管１４の側面に吸気口１４ａを設けてもよい。 FIG. 26 is a side view showing the outer shape of the horizontal axis submersible pump 1 according to the present embodiment. In this case, the overall shape of the suction cover 7 is substantially the same as that of the suction cover 7 in the first embodiment shown in FIG. 2, but an intake pipe 14 is connected to the suction cover 7 in the present embodiment. Specifically, for example, one end of the intake pipe 14 is connected to the side wall 11 of the suction cover 7 and communicates with the inside of the suction cover 7. The intake pipe 14 extends upward by a predetermined length and is bent in an inverted U shape. The other end of the intake pipe 14 is opened downward as an intake port 14a. According to this configuration, since suction is once performed upward from the intake port 14a, the intake port 14a and the inside of the pipe are prevented from being blocked by floating substances on the water surface. The other end may be closed and the intake port 14 a may be provided on the side surface of the intake pipe 14.
　なお、吸気管１４の曲管方向は、特に限定されるものではないが、水面の浮遊物等との衝突による損傷を抑止するために、吸込カバー７の上壁１０の上方で開口し、上壁１０の前縁１３から上方に防護壁３１を突出させることが望ましい。また、吸気管１４の吸気口１４ａの高さ方向の位置及び管径は、機場や横軸水中ポンプ１の仕様等の運転条件から適宜決定される。 The direction of the bent pipe of the intake pipe 14 is not particularly limited, but is opened above the upper wall 10 of the suction cover 7 in order to suppress damage due to collision with floating substances on the water surface. It is desirable to project the protective wall 31 upward from the front edge 13 of the wall 10. Further, the position in the height direction of the intake port 14a and the pipe diameter of the intake pipe 14 are appropriately determined from the operating conditions such as the machine field and the specifications of the horizontal axis submersible pump 1.
　図２７は、本実施形態に係る横軸水中ポンプ１の他の外形を示す側面図である。吸気管１４の一端は、図２７に示すように、吸込カバー７の上壁１０に接続されるものとしてもよい。 FIG. 27 is a side view showing another external shape of the horizontal-axis submersible pump 1 according to the present embodiment. One end of the intake pipe 14 may be connected to the upper wall 10 of the suction cover 7 as shown in FIG.
　図２８は、本実施形態に係る横軸水中ポンプ１の他の外形を示す側面図である。吸気管１４の一端は、図２８に示すように、ケーシング２の側壁に接続されるものとしてもよい。これらのように、吸気管１４の一端が横軸水中ポンプ１の羽根車３の上流側に空気を吸入させる位置に接続されるならば、吸気管１４の位置及び形状等は、限定されない。 FIG. 28 is a side view showing another external shape of the horizontal axis submersible pump 1 according to the present embodiment. One end of the intake pipe 14 may be connected to the side wall of the casing 2 as shown in FIG. As described above, as long as one end of the intake pipe 14 is connected to a position where air is sucked into the upstream side of the impeller 3 of the horizontal submersible pump 1, the position and shape of the intake pipe 14 are not limited.
　図２９は、本実施形態における横軸水中ポンプ１の運転モードを説明する図である。横軸水中ポンプ１が、予め設定された吸込側の２つの水位Ｈ，Ｍ（Ｈ＞Ｍ）を基準とした３つの運転モード、全量排水モードＭ１、気水混合排出モードＭ２及びアイドリングモードＭ３を有する点は、第１～第３実施形態と同様である。この場合、水位Ｈは、吸気管１４の吸気口１４ａの位置に設定される。水位Ｍは、前縁１３の頂部の位置に設定される。また、水位Ｌは、羽根車３が回転していても、水中電動機６に十分な水が供給できない水位の上限に設定される。 FIG. 29 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment. The horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. This is the same as in the first to third embodiments. In this case, the water level H is set at the position of the intake port 14 a of the intake pipe 14. The water level M is set at the top position of the leading edge 13. The water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
　図３０は、運転モードが全量排水モードＭ１（吸込側水位＞水位Ｈ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この全量排水モードＭ１では、横軸水中ポンプ１は、図７に示した第１実施形態における全量排水モードＭ１と同様に動作する。 FIG. 30 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H). In this total amount draining mode M1, the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG.
　図３１は、運転モードが気水混合排出モードＭ２（水位Ｈ≧吸込側水位＞水位Ｍ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この気水混合排出モードＭ２では、横軸水中ポンプ１は、図８に示した第１実施形態における気水混合排出モードＭ２と同様に動作する。 FIG. 31 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ≧ suction side water level> water level M). In the air / water mixed discharge mode M2, the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG.
　図３２は、運転モードがアイドリングモードＭ３（水位Ｍ≧吸込側水位＞水位Ｌ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。このアイドリングモードＭ３では、横軸水中ポンプ１は、図９に示した第１実施形態におけるアイドリングモードＭ３と同様に動作する。 FIG. 32 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ≧ suction side water level> water level L). In the idling mode M3, the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
　このように、本実施形態によれば、第１実施形態と同様の効果を奏する。 Thus, according to the present embodiment, the same effects as in the first embodiment can be obtained.
（第５実施形態）
　次に、本発明の第５実施形態に係る横軸水中ポンプについて説明する。本実施形態に係る横軸水中ポンプにおいて、一端が吸込カバー７又はケーシング２に接続され、他端が開放されている吸気口である吸気管を備える点は、第４実施形態と同様である。その上で、本実施形態に係る横軸水中ポンプの特徴は、運転モードを決定するための水位判断に第２吸気開口を用いない点にある。以下、第１実施形態に係る横軸水中ポンプ１と同一部分には同一の符号を付して説明する。 (Fifth embodiment)
Next, a horizontal axis submersible pump according to a fifth embodiment of the present invention will be described. The horizontal axis submersible pump according to the present embodiment is the same as the fourth embodiment in that it includes an intake pipe that is an intake port having one end connected to the suction cover 7 or the casing 2 and the other end open. In addition, the horizontal axis submersible pump according to the present embodiment is characterized in that the second intake opening is not used for water level judgment for determining the operation mode. Hereinafter, the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
　図３３は、本実施形態に係る横軸水中ポンプ１の外形を示す側面図である。この場合、吸込カバー７の全体形状は、図２に示す第１実施形態における吸込カバー７とほぼ同一であるが、本実施形態における吸込カバー７には、吸気管１４が接続されている。具体的には、例えば、吸気管１４の一端は、吸込カバー７の側壁１１に接続され、吸込カバー７の内部に連通する。吸気管１４は、所定の長さだけ上方に延設される。そして、吸気管１４の他端は、水平に曲管されて吸気口１４ａとして開放される。なお、他端を閉塞し、吸気管１４の側面に吸気口１４ａを設けてもよい。 FIG. 33 is a side view showing the outer shape of the horizontal-axis submersible pump 1 according to the present embodiment. In this case, the overall shape of the suction cover 7 is substantially the same as that of the suction cover 7 in the first embodiment shown in FIG. 2, but an intake pipe 14 is connected to the suction cover 7 in the present embodiment. Specifically, for example, one end of the intake pipe 14 is connected to the side wall 11 of the suction cover 7 and communicates with the inside of the suction cover 7. The intake pipe 14 extends upward by a predetermined length. The other end of the intake pipe 14 is bent horizontally and opened as an intake port 14a. The other end may be closed and the intake port 14 a may be provided on the side surface of the intake pipe 14.
　本実施形態では、気水混合排出モードＭ２時に吸気口１４ａから吸気することができるように、気水混合排出モードＭ２時の水位よりも上方に吸気口１４ａを位置させる。なお、水面の浮遊物等が吸気口１４ａを閉塞することを抑止するために、吸気口１４ａは、貯水槽の最大水位より上方位置に開放させておくことが望ましい。また、吸気管１４と水面の浮遊物等との衝突による損傷を抑止するために、必要に応じて防護壁３１等を設けてもよい。 In the present embodiment, the intake port 14a is positioned above the water level in the air / water mixture discharge mode M2 so that air can be drawn from the intake port 14a in the air / water mixture discharge mode M2. In addition, in order to prevent the floating surface etc. on the water surface from blocking the intake port 14a, the intake port 14a is desirably opened to a position above the maximum water level of the water storage tank. Further, a protective wall 31 or the like may be provided as necessary in order to suppress damage due to collision between the intake pipe 14 and floating matter on the water surface.
　なお、吸気管１４の一端が横軸水中ポンプ１の羽根車３の上流側に空気を吸入させる位置に接続されるならば、吸込カバー７の上壁１０やケーシング２等に接続されてもよい。また、吸気管１４の管径等は、機場や横軸水中ポンプ１の仕様等の運転条件から適宜決定される。 If one end of the intake pipe 14 is connected to a position where air is sucked into the upstream side of the impeller 3 of the horizontal axis submersible pump 1, it may be connected to the upper wall 10 of the suction cover 7, the casing 2, or the like. . In addition, the pipe diameter of the intake pipe 14 and the like are appropriately determined from the operating conditions such as the machine field and the specifications of the horizontal axis submersible pump 1.
　また、吸気管１４は、その内部に空気量調整機構を備える。図３４Ａ及び図３４Ｂは、空気量調整機構３３の構成を示す概略図である。上流側の水位に応じて、横軸水中ポンプ１の羽根車３へ押し込み圧力が変動し、ポンプ内圧が変動する。空気量調整機構３３は、このポンプ内圧に応じて所定の空気量を横軸水中ポンプ１に供給するものである。空気量調整機構３３としては、図３４Ａに示すように、オリフィス板等の抵抗体３３ａを用いることができ、又は、図３４Ｂに示すように、所定の圧力を閾値にして開閉する圧力弁３３ｂを用いることもできる。本実施形態では、吸込側の水位が低下した際に所定の空気量を流入させることで、横軸水中ポンプ１の運転モードが、気水混合排出モードＭ２に切り替わる。具体的には、吸込側の水位が低下すると、水頭による押し込み圧力が低下して定格回転数で運転している羽根車３の上流側（吸込側）が負圧となる。その負圧が空気量調整機構３３の抵抗値より大きな負圧（又は設定圧力の検知による圧力弁開放）となった場合、大気に開放されている吸気口１４ａよりケーシング２内に空気が流入し、気水混合状態にて排出が行われる。なお、空気量調整機構３３の抵抗値や設定圧力等は、横軸水中ポンプ１の仕様や運転条件等に応じて適宜設定される。 In addition, the intake pipe 14 includes an air amount adjusting mechanism therein. 34A and 34B are schematic views showing the configuration of the air amount adjustment mechanism 33. Depending on the upstream water level, the pushing pressure fluctuates into the impeller 3 of the horizontal-axis submersible pump 1, and the pump internal pressure fluctuates. The air amount adjusting mechanism 33 supplies a predetermined amount of air to the horizontal axis submersible pump 1 in accordance with the pump internal pressure. As the air amount adjusting mechanism 33, a resistor 33a such as an orifice plate can be used as shown in FIG. 34A, or a pressure valve 33b that opens and closes with a predetermined pressure as a threshold as shown in FIG. 34B. It can also be used. In this embodiment, the operation mode of the horizontal-axis submersible pump 1 is switched to the air / water mixing / discharging mode M2 by flowing a predetermined amount of air when the water level on the suction side is lowered. Specifically, when the water level on the suction side is lowered, the pushing pressure by the water head is lowered, and the upstream side (suction side) of the impeller 3 operating at the rated rotational speed becomes a negative pressure. When the negative pressure becomes a negative pressure larger than the resistance value of the air amount adjusting mechanism 33 (or the pressure valve is opened by detecting the set pressure), air flows into the casing 2 from the intake port 14a opened to the atmosphere. In the air-water mixed state, discharge is performed. Note that the resistance value, the set pressure, and the like of the air amount adjusting mechanism 33 are appropriately set according to the specifications and operating conditions of the horizontal axis submersible pump 1.
　図３５は、本実施形態における横軸水中ポンプ１の運転モードを説明する図である。横軸水中ポンプ１が、予め設定された吸込側の２つの水位Ｈ，Ｍ（Ｈ＞Ｍ）を基準とした３つの運転モード、全量排水モードＭ１、気水混合排出モードＭ２及びアイドリングモードＭ３を有する点は、第１～第４実施形態と同様である。この場合、水位Ｈは、気水混合排出モードＭ２の上端として予め規定される。そして、空気量調整機構３３は、吸込側水位が水位Ｈとなったときに気水混合排出モードＭ２となるよう、予め設定される。水位Ｍは、前縁１３の頂部の位置に設定される。また、水位Ｌは、羽根車３が回転していても、水中電動機６に十分な水が供給できない水位の上限に設定される。 FIG. 35 is a diagram for explaining an operation mode of the horizontal-axis submersible pump 1 in the present embodiment. The horizontal-axis submersible pump 1 has three operation modes based on two preset water levels H and M (H> M), a total drainage mode M1, an air-water mixed discharge mode M2, and an idling mode M3. This is the same as the first to fourth embodiments. In this case, the water level H is defined in advance as the upper end of the air / water mixture discharge mode M2. And the air quantity adjustment mechanism 33 is preset so that it may become the air-water mixing discharge mode M2 when the suction side water level becomes the water level H. The water level M is set at the top position of the leading edge 13. The water level L is set to the upper limit of the water level at which sufficient water cannot be supplied to the submersible electric motor 6 even when the impeller 3 is rotating.
　図３６は、運転モードが全量排水モードＭ１（吸込側水位＞水位Ｈ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この全量排水モードＭ１では、横軸水中ポンプ１は、図７に示した第１実施形態における全量排水モードＭ１と同様に動作する。ただし、本実施形態では、空気量調整機構３３の構成によっては、横軸水中ポンプ１の内部に連通する開口（空気量調整機構３３及び開口部８）は、全て没水のみならず、全て閉止している場合も含まれる。 FIG. 36 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level H). In this total amount draining mode M1, the horizontal axis submersible pump 1 operates in the same manner as the full amount draining mode M1 in the first embodiment shown in FIG. However, in the present embodiment, depending on the configuration of the air amount adjusting mechanism 33, all the openings (air amount adjusting mechanism 33 and opening 8) communicating with the inside of the horizontal axis submersible pump 1 are not only submerged but also all closed. It is also included if you are.
　図３７は、運転モードが気水混合排出モードＭ２（水位Ｈ≧吸込側水位＞水位Ｍ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この気水混合排出モードＭ２では、横軸水中ポンプ１は、図８に示した第１実施形態における気水混合排出モードＭ２と同様に動作する。ただし、本実施形態では、上記のとおり、空気量調整機構３３が予め気水混合排出モードＭ２上端水位で吸気開始する抵抗値に設定されていることにより、運転モードが気水混合排出モードＭ２に切り替わる。 FIG. 37 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the air / water mixed discharge mode M2 (water level H ≧ suction side water level> water level M). In the air / water mixed discharge mode M2, the horizontal axis submersible pump 1 operates in the same manner as the air / water mixed discharge mode M2 in the first embodiment shown in FIG. However, in the present embodiment, as described above, since the air amount adjustment mechanism 33 is set in advance to a resistance value at which intake starts at the upper water level of the air / water mixture discharge mode M2, the operation mode is changed to the air / water mixture discharge mode M2. Switch.
　図３８は、運転モードがアイドリングモードＭ３（水位Ｍ≧吸込側水位＞水位Ｌ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。このアイドリングモードＭ３では、横軸水中ポンプ１は、図９に示した第１実施形態におけるアイドリングモードＭ３と同様に動作する。 FIG. 38 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level M ≧ suction side water level> water level L). In the idling mode M3, the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
　このように、本実施形態によれば、第１実施形態と同様の効果を奏する。 Thus, according to the present embodiment, the same effects as in the first embodiment can be obtained.
（第６実施形態）
　次に、本発明の第６実施形態に係る横軸水中ポンプについて説明する。従来の横軸水中ポンプにおいて、水位が低下したときにケーシング内で水と空気とを攪拌するアイドリングモードでの運転中は、水中電動機の冷却を行うことが難しかった。これに対して、本実施形態では、羽根車の下端から所定の吐出角度θ以上となる羽根車の位置に水位を合わせることで、アイドリングモードでの運転中でもケーシング内に水を滞留させて水中電動機が没水する状態を維持させることで、水中電動機を冷却する。以下、第１実施形態に係る横軸水中ポンプ１と同一部分には同一の符号を付して説明する。 (Sixth embodiment)
Next, a horizontal axis submersible pump according to a sixth embodiment of the present invention will be described. In the conventional horizontal-axis submersible pump, it is difficult to cool the submersible motor during the idling mode in which water and air are stirred in the casing when the water level is lowered. On the other hand, in the present embodiment, the water level is adjusted to the position of the impeller having a predetermined discharge angle θ or more from the lower end of the impeller, so that the water is retained in the casing even during operation in the idling mode. The submersible electric motor is cooled by maintaining the submerged state. Hereinafter, the same parts as those of the horizontal axis submersible pump 1 according to the first embodiment will be described with the same reference numerals.
　なお、以下の説明では、羽根車３の位置を基準として吸込カバー７の前縁１３等の高さ位置を規定する点について理解しやすいように、便宜上、横軸水中ポンプ１が、全量排水モードとアイドリングモードとの２つの運転モードのみを有するものとする。しかし、この場合でも、全量排水モードとアイドリングモードとの間の移行時には気水混合状態が存在する。ただし、本実施形態でいう気水混合状態は、上記各実施形態で説明した気水混合排出モードＭ２のような、本発明の各効果を得るために積極的に設けられた運転モードとは異なるものである。したがって、気水混合排出モードを含む３つの運転モードを有する上記各実施形態に係る横軸水中ポンプ１に対しても、本実施形態の内容は適用可能である。 In the following description, for the sake of convenience, the horizontal-axis submersible pump 1 is configured to be in a full drainage mode so that it is easy to understand that the height position of the front edge 13 and the like of the suction cover 7 is defined based on the position of the impeller 3. And only two operation modes, i.e., idling mode. However, even in this case, an air-water mixed state exists at the time of transition between the full drainage mode and the idling mode. However, the air / water mixed state referred to in the present embodiment is different from the operation mode positively provided to obtain the effects of the present invention, such as the air / water mixed discharge mode M2 described in the above embodiments. Is. Therefore, the content of this embodiment is applicable also to the horizontal-axis submersible pump 1 which concerns on each said embodiment which has three operation modes including air-water mixing discharge mode.
　図３９は、本実施形態に係る横軸水中ポンプ１の構成を示す側断面図である。本実施形態に係る横軸水中ポンプ１では、第１実施形態の場合と比較して、吸込カバー７の前縁１３の高さ位置Ａが羽根車３の位置を基準として規定される点が異なる。 FIG. 39 is a side sectional view showing the configuration of the horizontal axis submersible pump 1 according to the present embodiment. The horizontal axis submersible pump 1 according to this embodiment differs from the first embodiment in that the height position A of the front edge 13 of the suction cover 7 is defined based on the position of the impeller 3. .
　図４０Ａは、羽根車３が有する１枚の羽根を回転軸方向から見た、羽根車３の要部正面図である。図中、吸込カバー７の前縁１３の高さ位置に相当する位置を、前縁１３の高さ位置の符号に合わせてＡとし、羽根車３のボス部の位置をＡｉとし、羽根車３の外終端の位置をＡｏとしている。また、図４０Ｂは、図４０Ａに示す各位置に対応した、羽根車３の展開図である。位置Ａでの吐出角度はθであり、位置Ａｉでの吐出角度はθｉであり、位置Ａｏでの吐出角度はθｏである。中心に近づく程、吐出角度は大きくなり、中心から遠ざかる程（外周に近づく程）θは小さくなるため、θｉ＞θ＞θｏとなる。一般的にθが大きい位置で排出される流体に付与される圧力は高く、θが小さい位置で排出される流体に付与される圧力は低い。 FIG. 40A is a front view of the main part of the impeller 3 when one blade of the impeller 3 is viewed from the direction of the rotation axis. In the drawing, the position corresponding to the height position of the front edge 13 of the suction cover 7 is A according to the sign of the height position of the front edge 13, the position of the boss portion of the impeller 3 is Ai, and the impeller 3. The position of the outer end of is Ao. FIG. 40B is a development view of the impeller 3 corresponding to each position shown in FIG. 40A. The discharge angle at position A is θ, the discharge angle at position Ai is θi, and the discharge angle at position Ao is θo. The closer to the center, the larger the discharge angle, and the further away from the center (the closer to the outer periphery), the smaller θ, so θi> θ> θo. Generally, the pressure applied to the fluid discharged at a position where θ is large is high, and the pressure applied to the fluid discharged at a position where θ is small is low.
　主軸４の鉛直方向下方側では、水位が低下すると、吐出角度θが小さい位置で水と羽根車３とが接触するので、羽根車３が水に付与する圧力が小さくなる。特に、吸込カバー７の開口部８から空気が流入し、水と空気との混合流体を排出しようとするときは、水と空気との流入比に応じて運転モードが変化する。 On the lower side in the vertical direction of the main shaft 4, when the water level decreases, the water and the impeller 3 come into contact with each other at a position where the discharge angle θ is small, so that the pressure applied to the water by the impeller 3 is reduced. In particular, when air flows from the opening 8 of the suction cover 7 and a mixed fluid of water and air is to be discharged, the operation mode changes according to the inflow ratio of water and air.
　水の流入比が大きい場合は、吐出圧力にてケーシング２の吐出側に支持されたフラップゲート９が開いて排水するが、空気の流入比が大きい場合には、吐出圧力が低くなってフラップゲート９を開くことができず、ケーシング２内で水と空気とが攪拌される。 When the water inflow ratio is large, the flap gate 9 supported on the discharge side of the casing 2 is opened and drained at the discharge pressure, but when the air inflow ratio is large, the discharge pressure is lowered and the flap gate is discharged. 9 cannot be opened, and water and air are stirred in the casing 2.
　ここで、水位が、主軸４の鉛直方向下方側で、羽根車３の所定の吐出角度θの位置にあるときには、定格回転数にて、かつ、フラップゲート９を閉塞した状態で、ケーシング２内に水中電動機６が没水する水位まで水を滞留させた状態を維持させることができる。そして、このような所定の吐出角度θとなるときの水位は、羽根車３下端から羽根車直径比の１０～２５％上方であり、望ましくは１０～２０％上方である。 Here, when the water level is at the position of the predetermined discharge angle θ of the impeller 3 on the lower side in the vertical direction of the main shaft 4, the casing 2 is closed at the rated speed and with the flap gate 9 closed. It is possible to maintain the state in which the water is retained up to the water level at which the submersible electric motor 6 is submerged. The water level at the predetermined discharge angle θ is 10 to 25% above the impeller diameter ratio from the lower end of the impeller 3, and preferably 10 to 20% above.
　なお、水位が上昇して羽根車３の吐出角度θより大きい位置で接触すると、フラップゲート９が開いて水が排出される。一方、水位が下降して羽根車３の吐出角度θより小さい位置で接触すると、水中電動機６が没水する高さまでケーシング２内の水を維持することができない。 When the water level rises and contacts at a position larger than the discharge angle θ of the impeller 3, the flap gate 9 is opened and water is discharged. On the other hand, when the water level drops and contacts at a position smaller than the discharge angle θ of the impeller 3, the water in the casing 2 cannot be maintained up to a height at which the submersible electric motor 6 is submerged.
　図４１は、本実施形態における吸込カバー７の形状を示す三面図である。吸込カバー７は、上壁１０と、上壁１０の両側端からそれぞれ下方に延設される２つの側壁１１と、ケーシング２に接続するフランジ１２とを有する。上壁１０は、吸込側（側面図の左方向）に向かって下方に傾斜している。側壁１１の下端は、上壁１０の前縁１３の両端から横軸水中ポンプ１のケーシング２下方近傍までそれぞれ傾斜している。前縁１３は、羽根車３下端近傍の水位まで位置している。より具体的には、羽根車下端から羽根車直径比の１０～２５％上方に位置していることが望ましい。 FIG. 41 is a three-side view showing the shape of the suction cover 7 in the present embodiment. The suction cover 7 includes an upper wall 10, two side walls 11 extending downward from both side ends of the upper wall 10, and a flange 12 connected to the casing 2. The upper wall 10 is inclined downward toward the suction side (left direction in the side view). The lower end of the side wall 11 is inclined from both ends of the front edge 13 of the upper wall 10 to the vicinity of the lower part of the casing 2 of the horizontal axis submersible pump 1. The leading edge 13 is located up to the water level near the lower end of the impeller 3. More specifically, it is desirable to be located 10 to 25% above the impeller diameter ratio from the lower end of the impeller.
　吸込カバー７の開口部８は、吸込側の方が他の側よりも高くなるように傾いた状態で設けられている、本実施形態における第１吸込開口である。水位が低下してくると開口部８の最上位に位置する前縁１３下方から徐々に吸込カバー７内に空気が流入する。前縁１３が羽根車３下端近傍の高さに位置しているので、低水位時まで全量排水モードでの運転が可能であり、アイドリングモードでの運転時には、騒音を抑制し、ケーシング２内からの水飛散を抑止し得る。 The opening 8 of the suction cover 7 is a first suction opening in the present embodiment, which is provided in an inclined state so that the suction side is higher than the other side. When the water level decreases, air gradually flows into the suction cover 7 from below the front edge 13 located at the top of the opening 8. Since the front edge 13 is located at the height near the lower end of the impeller 3, it is possible to operate in the full drainage mode until the low water level, and during operation in the idling mode, noise is suppressed and the casing 2 Can prevent water splashing.
　なお、前縁１３の位置を、羽根車３下端近傍の水位まで、具体的には、羽根車３下端から羽根車直径比の１０～２５％上方とすることは、上記のように、本実施形態に限らず、上記の各実施形態で採用される各種の吸込カバー７に適用可能である。ただし、吸込カバー７が図３に示すような前壁１５を有する場合には、ここでいう前縁１３の位置は、前壁１５の下端の位置に相当する。これにより、各実施形態における吸込カバー７の形状特有の効果に加えて、上記と同様、低水位時まで全量排水モードでの運転が可能となるなどの効果も奏する。 Note that, as described above, the position of the front edge 13 is set to the water level near the lower end of the impeller 3, specifically, 10 to 25% above the impeller diameter ratio from the lower end of the impeller 3. The present invention is not limited to the form, and can be applied to various suction covers 7 employed in the above embodiments. However, when the suction cover 7 has the front wall 15 as shown in FIG. 3, the position of the front edge 13 here corresponds to the position of the lower end of the front wall 15. Thereby, in addition to the effect peculiar to the shape of the suction cover 7 in each embodiment, there is also an effect that, in the same manner as described above, the operation in the full drainage mode is possible until the low water level.
　図４２は、横軸水中ポンプ１の性能曲線を表すグラフであり、横軸に流量を取り、縦軸に揚程及び動力を取っている。通常時の全量排水運転の仕様点流量はＱ１であり、揚程はＨ１となる。また、動力は流量Ｑ１時のＰ１となる。排出側の水位が増加して背圧が高くなると、流量が減少して徐々にＱ１の左側に移行してくる。このとき、横軸水中ポンプ１は、全量排水モードでの運転となる。 FIG. 42 is a graph showing the performance curve of the horizontal axis submersible pump 1, wherein the horizontal axis indicates the flow rate and the vertical axis indicates the lift and power. The specification point flow rate of the full drainage operation at normal time is Q1, and the head is H1. The power is P1 at the flow rate Q1. When the water level on the discharge side increases and the back pressure increases, the flow rate decreases and gradually shifts to the left side of Q1. At this time, the horizontal-axis submersible pump 1 is operated in the full drainage mode.
　吸込側の水位が低下して吸込カバー７の開口部８から空気が流入すると、ケーシング２内は気水混合状態となり、揚程曲線及び動力曲線は、グラフ中の波線のように、比例減少した曲線となる。減少比は、空気の流入量に応じて変動し、空気の流入量が多いほど曲線が減少する。 When the water level on the suction side decreases and air flows in from the opening 8 of the suction cover 7, the inside of the casing 2 is in an air-water mixed state, and the lift curve and power curve are proportionally reduced curves as indicated by the wavy lines in the graph. It becomes. The reduction ratio varies according to the inflow amount of air, and the curve decreases as the inflow amount of air increases.
　更に水位が低下して吐出圧力が低下すると、横軸水中ポンプ１は、フラップゲート９を閉塞した状態での運転、すなわちアイドリングモードでの運転となる。このときの流量はゼロとなり、動力はＰ２となる。一般的に軸流羽根は流量がゼロ付近で動力が上昇するので、できるだけ多くの空気を吸入する低水位時にアイドリングモードに移行するように設定しておくことが望ましい。これにより、横軸水中ポンプ１は、仕様点動力Ｐ１より低動力Ｐ２(Ｐ２＜Ｐ１)にて省エネ運転を行うことができる。 When the water level further decreases and the discharge pressure decreases, the horizontal-axis submersible pump 1 operates in a state where the flap gate 9 is closed, that is, in an idling mode. At this time, the flow rate becomes zero and the power becomes P2. Generally, since the power of the axial flow vane increases when the flow rate is close to zero, it is desirable to set the mode so as to shift to the idling mode at a low water level where as much air as possible is sucked. Thereby, the horizontal-axis submersible pump 1 can perform an energy-saving operation with power P2 (P2 <P1) lower than the specification point power P1.
　空気の流入開始は、吸込カバー７の前縁１３（又は前壁１５の下端）の高さで決定される。前縁１３の位置が高いと、早々に開口部８から空気が流入して気水混合状態となり、揚程が低下して排出側の水位増加に対応できず、低水位時の排出ができない。また、水位低下時のアイドリングモード中にケーシング２内の水が開口部８から吸込側に飛散しやすくなるとともに、ケーシング２内での攪拌に起因する騒音が発生する。そこで、吸込カバー７の前縁１３の位置を所定の高さに設定しておくことで、水位が前縁１３の高さに低下するまで水のみの全量排水モードで運転し、吸込側の水を早急に排出することが可能となる。また、水位低下時には、空気の流入開始に合わせてアイドリングモードとなり、ケーシング２内で水を維持させた状態で運転を継続するので、水中電動機６を冷却することができる。 The start of air inflow is determined by the height of the front edge 13 of the suction cover 7 (or the lower end of the front wall 15). If the position of the leading edge 13 is high, air will quickly flow in from the opening 8 and a mixed state of air and water will occur, the head will be lowered, and it will not be possible to cope with an increase in the water level on the discharge side, and discharge at a low water level will not be possible. Further, the water in the casing 2 is likely to be scattered from the opening 8 to the suction side during the idling mode when the water level is lowered, and noise due to stirring in the casing 2 is generated. Therefore, by setting the position of the front edge 13 of the suction cover 7 to a predetermined height, the water level is reduced to the height of the front edge 13, and the operation is performed in the water-only drainage mode. Can be discharged immediately. Further, when the water level is lowered, the idling mode is set in accordance with the start of the inflow of air, and the operation is continued in a state where the water is maintained in the casing 2, so that the underwater electric motor 6 can be cooled.
　なお、前縁１３の高さが低すぎると、空気の流入開始時には、ケーシング２内の水が不足するので、水中電動機６を冷却することが難しい。そこで、気水混合状態でフラップゲート９が開かない位置以下で空気の流入開始を行い、かつ、水中電動機６を冷却することができるだけの水量をケーシング２内に維持することができる位置以上の高さ位置に吸込カバー７の前縁１３が設定される。具体的には、吸込カバー７の前縁１３の高さ位置は、上記のとおり、羽根車３下端から羽根車直径比の１０～２５％上方であり、望ましくは１０～２０％上方である。 If the height of the leading edge 13 is too low, it is difficult to cool the submersible electric motor 6 because water in the casing 2 is insufficient at the start of air inflow. Therefore, the air flow starts at a position where the flap gate 9 does not open in the air / water mixture state, and the amount of water that can cool the submersible electric motor 6 is maintained at a level higher than the position at which the casing 2 can be maintained. The front edge 13 of the suction cover 7 is set at this position. Specifically, as described above, the height position of the front edge 13 of the suction cover 7 is 10 to 25% above the impeller diameter ratio from the lower end of the impeller 3, and preferably 10 to 20% above.
　図４３は、本実施形態における横軸水中ポンプ１の運転モードを説明する図である。本実施形態では、上記の各実施形態とは異なり、横軸水中ポンプ１は、予め設定された吸込側の１つの水位Ｌを基準とした２つの運転モード、全量排水モードＭ１及びアイドリングモードＭ３のみを有する。この場合、水位Ｌは、前縁１３の高さ位置に設定される。 FIG. 43 is a diagram for explaining the operation mode of the horizontal-axis submersible pump 1 in the present embodiment. In the present embodiment, unlike each of the above-described embodiments, the horizontal axis submersible pump 1 has only two operation modes based on a preset water level L on the suction side, a full drainage mode M1 and an idling mode M3. Have In this case, the water level L is set to the height position of the leading edge 13.
　図４４は、運転モードが全量排水モードＭ１（吸込側水位＞水位Ｌ）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。この全量排水モードＭ１でも、横軸水中ポンプ１は、図７に示した第１実施形態における全量排水モードＭ１と同様に動作する。 FIG. 44 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the full drainage mode M1 (suction side water level> water level L). Even in this total drainage mode M1, the horizontal axis submersible pump 1 operates in the same manner as the full drainage mode M1 in the first embodiment shown in FIG.
　図４５は、運転モードがアイドリングモードＭ３（水位Ｌ≧吸込側水位）であるときの本実施形態における横軸水中ポンプ１の動作を説明する図である。このアイドリングモードＭ３でも、横軸水中ポンプ１は、図９に示した第１実施形態におけるアイドリングモードＭ３と同様に動作する。 FIG. 45 is a diagram for explaining the operation of the horizontal-axis submersible pump 1 in the present embodiment when the operation mode is the idling mode M3 (water level L ≧ suction side water level). Even in the idling mode M3, the horizontal axis submersible pump 1 operates in the same manner as the idling mode M3 in the first embodiment shown in FIG.
　本実施形態によれば、第１実施形態と同様の効果を奏する。具体的には、本実施形態では、吸込カバー７の前縁１３等の高さ位置を上記のとおり規定することで、アイドリングモードでの運転時も水中電動機６を冷却することができる。したがって、水中電動機６は、アイドリングモード中も定格回転数での運転を維持し、水中電動機６すなわちポンプのＯＮ／ＯＦＦの繰り返し頻度を低下させることができる。さらに、本実施形態に係る横軸水中ポンプ１は、上記各実施形態のいずれかと組み合わせることで、気水混合排水モードＭ２を含む３つの運転モードを採用することが可能となる。これにより、本実施形態に係る横軸水中ポンプ１も、上記各実施形態による特有の効果を同時に奏することが可能となる。 According to this embodiment, the same effects as those of the first embodiment are obtained. Specifically, in this embodiment, by defining the height positions of the front edge 13 and the like of the suction cover 7 as described above, the submersible electric motor 6 can be cooled even during operation in the idling mode. Therefore, the submersible electric motor 6 can maintain the operation at the rated rotational speed even in the idling mode, and can reduce the repetition frequency of the submersible electric motor 6, that is, the pump ON / OFF. Furthermore, the horizontal-axis submersible pump 1 according to the present embodiment can employ three operation modes including the air / water mixed drainage mode M2 by combining with any of the above-described embodiments. Thereby, the horizontal-axis submersible pump 1 which concerns on this embodiment can also show | play simultaneously the peculiar effect by said each embodiment.
（他の実施形態）
　上記各実施形態では、吸込カバー７の形状に関して複数例示したが、本発明は、これらに限定されるものではない。例えば、以下のような変形も可能である。 (Other embodiments)
In the above embodiments, a plurality of examples of the shape of the suction cover 7 are illustrated, but the present invention is not limited to these. For example, the following modifications are possible.
　まず、上壁１０は、上記各実施形態では排出側から吸込側に向かって下方に傾斜しているものとしたが、水平であってもよい。一方、側壁１１の下端（端縁）も、上記各実施形態では前縁又は前壁側から排出側に向かって下方に傾斜しているものとしたが、水平であってもよい。 First, although the upper wall 10 is inclined downward from the discharge side toward the suction side in each of the above embodiments, it may be horizontal. On the other hand, the lower end (edge) of the side wall 11 is also inclined downward from the front edge or front wall side toward the discharge side in each of the above embodiments, but may be horizontal.
　図４６は、上壁１０が水平である吸込カバー７の形状を例示する二面図である。一方、図４７は、側壁１１の下端１１ａが水平である吸込カバー７の形状を例示する二面図である。なお、図４６及び図４７に示す吸込カバー７は、それぞれ、図３に示す吸込カバー７の形状を変形したものと想定している。特に、図４６に示す吸込カバー７のように上壁１０が水平である場合でも、いずれかの位置に第２吸込開口としての吸気部を形成しておくことで、第１～第５実施形態と同様に運転モードを設定することができる。例えば、図４６に示すように、上壁１０から下方に延設されている前壁１５に、第２吸込開口としての吸気孔１６が形成されている場合には、図３に示した吸込カバー７を用いる場合と同様に適用することができる。 FIG. 46 is a two-side view illustrating the shape of the suction cover 7 in which the upper wall 10 is horizontal. On the other hand, FIG. 47 is a two-side view illustrating the shape of the suction cover 7 in which the lower end 11a of the side wall 11 is horizontal. It is assumed that the suction cover 7 shown in FIGS. 46 and 47 is a modification of the shape of the suction cover 7 shown in FIG. In particular, even when the upper wall 10 is horizontal as in the suction cover 7 shown in FIG. 46, the first to fifth embodiments are formed by forming an intake portion as the second suction opening at any position. The operation mode can be set in the same manner as. For example, as shown in FIG. 46, when the suction hole 16 as the second suction opening is formed in the front wall 15 extending downward from the upper wall 10, the suction cover shown in FIG. It can be applied in the same manner as in the case of using 7.
　また、上壁１０が水平で、かつ、前壁が存在しない場合、上壁１０に第２吸込開口としての吸気部を形成しておくこともあり得る。例えば、上壁１０の高さ位置、すなわち、第２吸込開口が形成されている位置に相当する水位をＨとする。この場合、横軸水中ポンプ１の運転モードとしては、吸込側水位＞水位Ｈのときに全量排水モードＭ１、吸込側水位＝水位Ｈのときに気水混合排出モードＭ２、また、水位Ｈ＞吸込側水位のときにアイドリングモードＭ３と、それぞれ設定し得る。 Further, when the upper wall 10 is horizontal and there is no front wall, an air intake portion as a second suction opening may be formed in the upper wall 10. For example, the water level corresponding to the height position of the upper wall 10, that is, the position where the second suction opening is formed is defined as H. In this case, the operation mode of the horizontal axis submersible pump 1 is the total drainage mode M1 when the suction side water level> the water level H, the air / water mixed discharge mode M2 when the suction side water level = the water level H, and the water level H> suction. The idling mode M3 can be set for each side water level.
　また、側壁１１は、上記各実施形態では上壁１０の両端部から垂設されるものとしたが、下方に延設されるものであれば、吸込カバー７の外側又は内側に向かって傾斜するものであってもよいし、例えば、外側に丸みを帯びた形状であってもよい。また、ここでの上壁１０の両端部は、厳密な端のみを表すのではなく、両端から内側にずれた位置も許容される。 Moreover, although the side wall 11 shall be suspended from the both ends of the upper wall 10 in each said embodiment, if it is extended below, it will incline toward the outer side or the inner side of the suction cover 7. FIG. It may be a thing, for example, the shape rounded outside may be sufficient. Further, the both end portions of the upper wall 10 here do not represent only exact ends, but positions shifted from both ends to the inside are allowed.
　また、図２に示した吸込カバー７では、凸部を構成する上壁１０の前縁１３の形状が弓形であるものとしたが、例えば山形であってもよい。また、ここでの凸部は、必ずしも前縁１３の両端から開始される形状に限られるものではなく、前縁１３の一部が凸部を構成してもよい。さらに、凸部の設置数は、複数でもよい。 In the suction cover 7 shown in FIG. 2, the shape of the front edge 13 of the upper wall 10 constituting the convex portion is an arc shape, but may be a mountain shape, for example. Moreover, the convex part here is not necessarily restricted to the shape started from the both ends of the front edge 13, A part of front edge 13 may comprise a convex part. Furthermore, the number of convex portions may be plural.
　図４８は、前縁１３の一部が凸部４０を構成している吸込カバー７の形状を例示する斜視図である。この例では、凸部４０は、前縁１３の中心部に形成されており、その形状は、弓形である。図４９は、前縁１３の一部が凸部４０を構成している吸込カバー７の他の形状を例示する斜視図である。この例では、凸部４０は、前縁１３の中心部に形成されているが、その形状は、山形である。図５０は、前縁１３の一部が凸部４０を構成している吸込カバー７の他の形状を例示する斜視図である。この例では、凸部４０は、前縁１３に２つ形成されており、その形状は、各々弓形である。また、図５１は、吸込カバー７の他の形状を例示する斜視図である。上記の吸込カバー７の形状以外にも、上壁１０の前縁１３と側壁１１の前縁１１ｂとの縁部の組み合わせを凸部とみなすこともできる。すなわち、この場合の前縁１３の両端部は、前縁１１ｂの下端に相当する。 FIG. 48 is a perspective view illustrating the shape of the suction cover 7 in which a part of the front edge 13 constitutes the convex portion 40. In this example, the convex part 40 is formed in the center part of the front edge 13, and the shape is an arcuate shape. FIG. 49 is a perspective view illustrating another shape of the suction cover 7 in which a part of the front edge 13 constitutes the convex portion 40. In this example, although the convex part 40 is formed in the center part of the front edge 13, the shape is a mountain shape. FIG. 50 is a perspective view illustrating another shape of the suction cover 7 in which a part of the front edge 13 constitutes the convex portion 40. In this example, two convex portions 40 are formed on the front edge 13 and each has an arcuate shape. FIG. 51 is a perspective view illustrating another shape of the suction cover 7. In addition to the shape of the suction cover 7 described above, a combination of edges of the front edge 13 of the upper wall 10 and the front edge 11b of the side wall 11 can be regarded as a convex portion. That is, both ends of the front edge 13 in this case correspond to the lower end of the front edge 11b.
　また、図３及び図４に示した吸込カバー７では、前壁１５が上壁１０の前縁１３から下方に向かって延設されるものとしたが、前壁１５は、必ずしも前縁１３から延設されるものでなくてもよい。 In the suction cover 7 shown in FIGS. 3 and 4, the front wall 15 extends downward from the front edge 13 of the upper wall 10, but the front wall 15 does not necessarily extend from the front edge 13. It does not have to be extended.
　図５２は、吸込カバー７の他の形状を例示する側断面図である。前壁１５は、前縁１３から下流側にずれた上壁１０の内側から下方に向かって延設されるものとしてもよい。ここで、前壁１５が上壁１０の内側に連接される位置は、前壁１５の存在によって生じ得る吸込抵抗が無視できる位置とすることが望ましい。そこで、吸込カバー７のケーシング２に接続される側の端部から前壁１５までの間隔をＸとし、羽根車３の直径をＤとすると、間隔Ｘは、Ｄ～１．５Ｄ以上とすることが望ましい。なお、図５２に示す吸込カバー７は、図３及び図４に示した吸込カバー７において、上壁１０及び側壁１１が、共に前壁１５の位置から前側に突出するよう変形させたものと見なすこともできる。この場合、上壁１０及び側壁１１の突出量は、上記各実施形態で説明した効果を奏する限り、特に限定されるものではない。 FIG. 52 is a side cross-sectional view illustrating another shape of the suction cover 7. The front wall 15 may extend downward from the inside of the upper wall 10 that is shifted downstream from the front edge 13. Here, it is desirable that the position where the front wall 15 is connected to the inside of the upper wall 10 is a position where the suction resistance that may be caused by the presence of the front wall 15 can be ignored. Therefore, if the distance from the end of the suction cover 7 on the side connected to the casing 2 to the front wall 15 is X and the diameter of the impeller 3 is D, the distance X is D to 1.5D or more. Is desirable. 52, the suction cover 7 shown in FIG. 3 and FIG. 4 is regarded as having the upper wall 10 and the side wall 11 both deformed so as to protrude from the position of the front wall 15 to the front side. You can also. In this case, the protrusion amounts of the upper wall 10 and the side wall 11 are not particularly limited as long as the effects described in the above embodiments are achieved.
　また、図４に示した吸込カバー７では、第２吸込開口である吸気部１４が複数の切り欠きで構成され、全体的に見ると鋸状又は波状であるものとしたが、例えば単一の切り欠きだけで構成される場合もあり得る。ただし、吸気時の騒音を抑える観点から、切り欠きは複数存在する方が有利である。また、１つの切り欠きの形状も、弓形、山形又は凸形等、様々な形状が適用され得る。 Further, in the suction cover 7 shown in FIG. 4, the intake portion 14 that is the second suction opening is configured by a plurality of notches, and is generally saw-tooth or wave-shaped. There may be a case where only the notch is formed. However, it is advantageous to have a plurality of notches from the viewpoint of suppressing noise during intake. Various shapes such as an arc shape, a mountain shape, or a convex shape can be applied to the shape of one notch.
　また、図４に示した吸込カバー７では、複数の切り欠きで構成される吸気部１４が前壁１５に形成される場合を例示したが、上壁１０に形成されるものとしてもよく、更には、側壁１１の下端（端縁）に形成されるものとしてもよい。 Further, in the suction cover 7 shown in FIG. 4, the case where the intake portion 14 constituted by a plurality of notches is formed on the front wall 15 is exemplified, but it may be formed on the upper wall 10. May be formed at the lower end (edge) of the side wall 11.
　図５３は、吸気部１４としての複数の切り欠き４１が上壁１０に設けられた吸込カバー７の形状を示す斜視図である。一方、図５４は、吸気部１４としての複数の切り欠き４１が側壁１１の下端に設けられた吸込カバー７の形状を示す斜視図である。 FIG. 53 is a perspective view showing the shape of the suction cover 7 in which a plurality of cutouts 41 as the intake portion 14 are provided on the upper wall 10. On the other hand, FIG. 54 is a perspective view showing the shape of the suction cover 7 in which a plurality of cutouts 41 as the air intake portion 14 are provided at the lower end of the side wall 11.
　また、図３及び図４に示した吸込カバー７では、前壁１５が上壁１０の前縁１３から垂設されるものとしたが、下方に向かって延設されるならば、必ずしも垂設されなくてもよい。前壁１５は、例えば、吸込カバー７の内側に向かって傾斜するように延設されてもよいし、さらに上壁１０と曲面を介して接続されるものであってもよい。 In the suction cover 7 shown in FIGS. 3 and 4, the front wall 15 is suspended from the front edge 13 of the upper wall 10. It does not have to be done. For example, the front wall 15 may extend so as to incline toward the inside of the suction cover 7, or may be further connected to the upper wall 10 via a curved surface.
　図５５は、前壁１５が、吸込カバー７の内側に向かって傾斜し、かつ、上壁１０と曲面を介して接続されている吸込カバー７の形状を示す斜視図である。なお、図５５に示す吸込カバー７は、図４に示す吸込カバー７の形状を変形したものと想定している。前壁１５を吸込カバー７の内側に向かって傾斜させることで、切り欠きを有する前壁１５が上壁１０の前縁１３から垂設されている場合よりも、吸込カバー７の内部空間に対する開口部８の開口量が狭くなるので、騒音を外部に漏らしづらくなる。したがって、特に運転モードがアイドリングモードのときには、より騒音を抑制することができる。一方、吸込カバー７の先端に丸みを持たせることで、上流側から流れてくるゴミが、吸込カバー７の先端部に付着しづらくなる。 FIG. 55 is a perspective view showing the shape of the suction cover 7 in which the front wall 15 is inclined toward the inside of the suction cover 7 and connected to the upper wall 10 via a curved surface. Note that the suction cover 7 shown in FIG. 55 is assumed to be a modification of the shape of the suction cover 7 shown in FIG. By inclining the front wall 15 toward the inside of the suction cover 7, the opening to the internal space of the suction cover 7 can be achieved as compared with the case where the front wall 15 having a notch is suspended from the front edge 13 of the upper wall 10. Since the opening amount of the part 8 becomes narrow, it becomes difficult to leak noise to the outside. Therefore, particularly when the operation mode is the idling mode, noise can be further suppressed. On the other hand, since the tip of the suction cover 7 is rounded, dust flowing from the upstream side hardly adheres to the tip of the suction cover 7.
　なお、上記説明した各種の吸込カバー７の形状は、必ずしも個別に採用される必要はなく、各特徴を組み合わせた形状とすることも可能である。例えば、吸込カバー７は、図５３及び図５４に例示された２つの種類の吸気部１４を双方有するものとしてもよい。 It should be noted that the shapes of the various suction covers 7 described above do not necessarily have to be adopted individually, and may be a shape combining the features. For example, the suction cover 7 may have both of the two types of intake portions 14 illustrated in FIGS. 53 and 54.
　次に、横軸水中ポンプ１の全体構成に関して、上記各実施形態では、ポンプ本体が水面に対して平行に、すなわち水平に設置されるものとした。なお、ここでいうポンプ本体とは、ケーシング２、より具体的には、ケーシング２内に配置されている主軸４と同義である。しかし、本発明は、このようなポンプ本体が水平に設置されるポンプに限られず、ポンプ本体が吸込側下方に向かって傾斜して設置されるポンプにも適用可能である。 Next, regarding the overall configuration of the horizontal-axis submersible pump 1, in each of the above embodiments, the pump body is installed in parallel to the water surface, that is, horizontally. In addition, the pump main body here is synonymous with the main shaft 4 arrange | positioned in the casing 2 and the casing 2 more specifically. However, the present invention is not limited to a pump in which such a pump main body is installed horizontally, but can also be applied to a pump in which the pump main body is installed to be inclined downward on the suction side.
　また、上記各実施形態では、ケーシング２と吸込カバー７とが別体であるものとした。これは、吸込カバー７が破損したり、目的に合わせて吸込カバー７を別形状のものに変更したりする場合に、容易に別の吸込カバー７に交換することができる点で有利である。しかし、これは必須の構成ではなく、ケーシング２と吸込カバー７とが一体であってもよい。 Further, in each of the above embodiments, the casing 2 and the suction cover 7 are assumed to be separate bodies. This is advantageous in that the suction cover 7 can be easily replaced with another suction cover 7 when the suction cover 7 is damaged or when the suction cover 7 is changed to another shape according to the purpose. However, this is not an essential configuration, and the casing 2 and the suction cover 7 may be integrated.
　また、上記各実施形態では、羽根車３は、図１に示すように、ケーシング２内に収容されるよう支持されているが、主軸４を吸込カバー７に向けて延伸させることで、羽根車３が吸込カバー７内に延出している場合もあり得る。 Moreover, in each said embodiment, although the impeller 3 is supported so that it may be accommodated in the casing 2, as shown in FIG. 1, it is impeller by extending the main axis | shaft 4 toward the suction cover 7. FIG. It is possible that 3 extends into the suction cover 7.
　このように、本発明は、ここでは記載していない様々な実施の形態などを含むことは勿論である。したがって、本発明の技術的範囲は、上述の説明から妥当な特許請求の範囲に係る発明特定事項によってのみ定められる。 Thus, it goes without saying that the present invention includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is determined only by the invention specifying matters according to the scope of claims reasonable from the above description.
　特願２０１５－０９３９８３号（出願日：２０１５年５月１日）、特願２０１５－０９３９８４号（出願日：２０１５年５月１日）、特願２０１５－０９３９８５号（出願日：２０１５年５月１日）、特願２０１５－０９３９８６号（出願日：２０１５年５月１日）、特願２０１５－０９３９８７号（出願日：２０１５年５月１日）、特願２０１５－１４６２６０号（出願日：２０１５年７月２４日）の全内容は、ここに援用される。 Japanese Patent Application No. 2015-093983 (Application Date: May 1, 2015), Japanese Patent Application No. 2015-093984 (Application Date: May 1, 2015), Japanese Patent Application No. 2015-093985 (Application Date: May 2015) 1), Japanese Patent Application No. 2015-093986 (application date: May 1, 2015), Japanese Patent Application No. 2015-093987 (application date: May 1, 2015), Japanese Patent Application No. 2015-146260 (Application Date: The entire contents of July 24, 2015) are incorporated herein.
　１　　横軸水中ポンプ
　２　　ケーシング
　３　　羽根車
　７　　吸込カバー
　８　　開口部
　１４　吸気部 DESCRIPTION OF SYMBOLS 1 Horizontal axis submersible pump 2 Casing 3 Impeller 7 Suction cover 8 Opening part 14 Intake part

Claims (12)

  1. 　吸込口と排出口とを有するケーシングと、
    　前記ケーシング内で支持された羽根車と、
    　前記吸込口に接続された吸込カバーと、
    　前記吸込カバーに設けられ、前記羽根車の上端よりも低い位置に開口する第１吸込開口と、
    　前記吸込カバー及び前記ケーシングのうち少なくとも一方において前記羽根車よりも上流側に設けられ、前記第１吸込開口の上端よりも高い位置に開口する第２吸込開口と、
    を有する横軸水中ポンプ。     A casing having a suction port and a discharge port;
    An impeller supported in the casing;
    A suction cover connected to the suction port;
    A first suction opening provided in the suction cover and opening at a position lower than an upper end of the impeller;
    A second suction opening provided at an upstream side of the impeller in at least one of the suction cover and the casing, and opened at a position higher than an upper end of the first suction opening;
    A horizontal axis submersible pump.
  2. 　請求項１に記載の横軸水中ポンプであって、
    　前記吸込カバーは、
    　上壁と、
    　前記上壁から下方に延設される側壁と、を有し、
    　前記上壁の前縁は、該前縁の両端部より高い位置を有し、
    　前記第２吸込開口は、前記前縁と、該前縁の両端部を結ぶ直線とで囲まれた開口である。     The horizontal axis submersible pump according to claim 1,
    The suction cover is
    The upper wall,
    A side wall extending downward from the upper wall,
    The leading edge of the upper wall has a position higher than both ends of the leading edge;
    The second suction opening is an opening surrounded by the front edge and a straight line connecting both ends of the front edge.
  3. 　請求項１に記載の横軸水中ポンプであって、
    　前記吸込カバーは、
    　上壁と、
    　前記上壁から下方に延設される側壁と、
    　前記上壁から下方に延設される前壁と、を有し、
    　前記第２吸込開口は、前記前壁を貫通する孔である。     The horizontal axis submersible pump according to claim 1,
    The suction cover is
    The upper wall,
    A side wall extending downward from the upper wall;
    A front wall extending downward from the upper wall,
    The second suction opening is a hole that penetrates the front wall.
  4. 　請求項１に記載の横軸水中ポンプであって、
    　前記吸込カバーは、
    　上壁と、
    　前記上壁から下方に延設される側壁と、
    　前記上壁から下方に延設される前壁と、を有し、
    　前記第１吸込開口は、前記前壁の下端と、前記側壁の下端とで囲まれる開口であり、
    　前記第２吸込開口は、前記第１吸込開口に連通し、前記前壁に形成された少なくとも１以上の切り欠きと、前記前壁の下端を結ぶ直線とで囲まれた開口である。     The horizontal axis submersible pump according to claim 1,
    The suction cover is
    The upper wall,
    A side wall extending downward from the upper wall;
    A front wall extending downward from the upper wall,
    The first suction opening is an opening surrounded by a lower end of the front wall and a lower end of the side wall,
    The second suction opening is an opening that communicates with the first suction opening and is surrounded by at least one notch formed in the front wall and a straight line connecting the lower end of the front wall.
  5. 　請求項１に記載の横軸水中ポンプであって、
    　前記吸込カバーは、
    　上壁と、
    　前記上壁から下方に延設される側壁と、を有し、
    　前記第１吸込開口は、前記上壁の前縁と、前記側壁の下端とで囲まれる開口であり、
    　前記第２吸込開口は、前記第１吸込開口に連通し、前記上壁に形成された少なくとも１以上の切り欠きと、前記上壁の前縁を結ぶ直線とで囲まれた開口、又は、前記第１吸込開口に連通し、前記側壁に形成された少なくとも１以上の切り欠きと、前記側壁の下端を結ぶ直線とで囲まれた開口である。     The horizontal axis submersible pump according to claim 1,
    The suction cover is
    The upper wall,
    A side wall extending downward from the upper wall,
    The first suction opening is an opening surrounded by a front edge of the upper wall and a lower end of the side wall,
    The second suction opening communicates with the first suction opening, and is an opening surrounded by at least one notch formed in the upper wall and a straight line connecting the front edge of the upper wall, or The opening communicates with the first suction opening and is surrounded by at least one notch formed in the side wall and a straight line connecting the lower end of the side wall.
  6. 　請求項１に記載の横軸水中ポンプであって、
    　前記吸込カバーは、
    　上壁と、
    　前記上壁から下方に延設される側壁と、を有し、
    　前記第２吸込開口は、前記上壁又は前記側壁に形成された開口である。     The horizontal axis submersible pump according to claim 1,
    The suction cover is
    The upper wall,
    A side wall extending downward from the upper wall,
    The second suction opening is an opening formed in the upper wall or the side wall.
  7. 　請求項１に記載の横軸水中ポンプであって、
    　更に、一端が前記吸込カバー又は前記ケーシングに接続され、他端が開放されている吸気口である吸気管を備え、
    　前記吸込カバーは、
    　上壁と、
    　前記上壁から下方に延設される側壁と、を有し、
    　前記第２吸込開口は、前記吸気口である。     The horizontal axis submersible pump according to claim 1,
    Furthermore, the one end is connected to the suction cover or the casing, the other end is provided with an intake pipe that is an intake port that is open,
    The suction cover is
    The upper wall,
    A side wall extending downward from the upper wall,
    The second suction opening is the intake port.
  8. 　請求項２～７のいずれか１項に記載の横軸水中ポンプであって、
    　前記吸込カバーの前記上壁の前縁、又は、前記吸込カバーの前記上壁から下方に延設される前壁の下端は、前記羽根車の下端から前記羽根車の直径比で１０～２５％上方に位置する。     The horizontal axis submersible pump according to any one of claims 2 to 7,
    The front edge of the upper wall of the suction cover or the lower end of the front wall extending downward from the upper wall of the suction cover is 10 to 25% in terms of the diameter ratio of the impeller from the lower end of the impeller. Located above.
  9. 　請求項１～８のいずれか１項に記載の横軸水中ポンプであって、
    　更に、前記ケーシングの前記排出口の側に設けられ、該排出口から排出される流体の圧力により開閉可能なフラップゲートを備える。     A horizontal-axis submersible pump according to any one of claims 1 to 8,
    Further, a flap gate is provided on the discharge port side of the casing and can be opened and closed by the pressure of the fluid discharged from the discharge port.
  10. 　請求項１～９のいずれか１項に記載の横軸水中ポンプであって、
    　更に、前記ケーシングの内圧が所定の圧力に達したときに前記ケーシング内の空気を外部に排出するエア抜機構を備える。     A horizontal axis submersible pump according to any one of claims 1 to 9,
    Furthermore, an air vent mechanism is provided for discharging the air in the casing to the outside when the internal pressure of the casing reaches a predetermined pressure.
  11. 　排出開口と、
    　上壁と、
    　前記上壁から下方に延設される側壁と、
    　前記上壁から下方に延設される前壁と、
    　前記前壁の下端と前記側壁の下端とで囲まれる第１吸込開口と、
    　前記第１吸込開口に連通し、前記前壁に形成された少なくとも１以上の切り欠きと、前記前壁の下端を結ぶ直線とで囲まれた開口である第２吸込開口と、を有する、
    横軸水中ポンプに用いられる吸込カバー。     A discharge opening;
    The upper wall,
    A side wall extending downward from the upper wall;
    A front wall extending downward from the upper wall;
    A first suction opening surrounded by a lower end of the front wall and a lower end of the side wall;
    A second suction opening that communicates with the first suction opening and is surrounded by at least one notch formed in the front wall and a straight line connecting a lower end of the front wall;
    Suction cover used for horizontal axis submersible pumps.
  12. 　排出開口と、
    　上壁と、
    　前記上壁から下方に延設される側壁と、
    　前記上壁の前縁と前記側壁の下端とで囲まれる第１吸込開口と、
    　前記第１吸込開口に連通し、前記上壁に形成された少なくとも１以上の切り欠きと、前記上壁の前縁を結ぶ直線とで囲まれた開口、又は、前記第１吸込開口に連通し、前記側壁に形成された少なくとも１以上の切り欠きと、前記側壁の下端を結ぶ直線とで囲まれた開口である第２吸込開口と、を有する、
    横軸水中ポンプに用いられる吸込カバー。     A discharge opening;
    The upper wall,
    A side wall extending downward from the upper wall;
    A first suction opening surrounded by a front edge of the upper wall and a lower end of the side wall;
    An opening that communicates with the first suction opening and is surrounded by at least one notch formed in the upper wall and a straight line that connects a front edge of the upper wall, or communicates with the first suction opening. A second suction opening that is an opening surrounded by at least one notch formed in the side wall and a straight line connecting a lower end of the side wall,
    Suction cover used for horizontal axis submersible pumps.
PCT/JP2016/062987 2015-05-01 2016-04-26 Horizontal shaft submersible pump and suction cover used for horizontal shaft submersible pump WO2016178387A1 (en)

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KR1020177028665A KR102004207B1 (en) 2015-05-01 2016-04-26 Horizontal shaft submersible pump and suction cover used for horizontal shaft submersible pump
CN201680021343.3A CN107429701B (en) 2015-05-01 2016-04-26 The inhalation mask that horizontal axis immersible pump and horizontal axis immersible pump use
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