JP4495078B2 - Advance standby type vertical shaft pump - Google Patents

Description

  The present invention relates to a stand-by type vertical shaft pump that operates even when the water level in the water absorption tank is lower than the drainage water level above the impeller in the casing.

  In recent years, the underground penetration rate of rainwater has decreased due to urbanization and road paving. In addition, the occurrence of localized torrential rain due to the heat island phenomenon is increasing. Due to these causes, a large amount of rainwater tends to flow into the sewer drain pumping station in a short time. In order to cope with this short time and large amount of rainwater inflow, the pump is started in advance based on rainfall information, etc., and drainage starts at the same time as rainwater flows into the drainage pump station, and the water level in the water absorption tank There is an increasing demand for a pre-standby type pump that can maintain the operating state even if fluctuates.

  The so-called hunting operation is the most problematic in realizing the standby standby operation with the vertical shaft pump. This hunting operation will be described with reference to FIG. In FIG. 11, 1 is a casing of a vertical shaft, 2 is a rotating shaft, 3 is an impeller, and 4 is a discharge pipe. When the water level in the water absorption tank is at the drainage water level above the impeller 3 as shown in state 11-1, normal drainage operation is performed, and the water in the water absorption tank sucked up by the vertical shaft pump is drained from the discharge pipe 4. The When the water level falls to the drainage stop water level near the lower end of the casing 1 (the lower end of the suction bell) as shown in the state 11-2, a large amount of air instantaneously enters the casing 1 from the lower end of the casing 1. As a result, as shown in state 11-3, an air reservoir 5 is formed in a region below the impeller 3 in the casing 1, and a water column 6 is formed in the upper region. This state 11-3 is called an air lock operation. However, since the air in the air pool 5 rises into the water column 6, the air lock operation is immediately canceled and the state is shifted to the normal drain operation state as shown in the state 11-4. When water is discharged to the discharge pipe 4 in the normal drain operation in the state 11-4, the operation immediately returns to the air lock operation in the state 11-3. Eventually, the air lock operation in state 11-3 and the normal drain operation in state 11-4 are repeated in a very short time, and this is the hunting operation. This hunting operation generates large vibrations and adversely affects the stability and durability of the operation of the vertical shaft pump.

  Various attempts have been made to eliminate the hunting operation in the conventional stand-by type vertical shaft pump. For example, as shown in FIG. 12, the prior standby vertical shaft pump described in Patent Document 1 has an intake pipe 7 having one end opened in the casing 1 below the impeller 3 and the other end opened to the atmosphere. An air / water switching valve 8 that controls communication and blocking of the intake pipe 7 and a controller (not shown) that opens and closes the air / water switching valve 8 based on the detected water level of the water level gauge 9 are provided.

  The transition of the operation state will be described. At the drainage water level shown in the state 12-1, the air / water switching valve 8 is closed and the normal drainage operation is performed. When the water level drops to a predetermined drainage cutoff water level as shown in state 12-2, the air / water switching valve 8 is opened, and a large amount of air flows into the casing 1 from the intake pipe 7 at a time. As a result, as shown in state 12-3, the operation shifts to the air lock operation. Since a small amount of air is supplied to the air reservoir 5 through the intake pipe 7, the air lock operation is maintained and the hunting operation is not performed. As shown in state 12-4, when the water level recovers to a predetermined re-drainage start water level, the air-water switching valve 8 is closed, and the normal drainage operation is performed.

  Further, as shown in FIG. 13, the prior standby vertical shaft pump described in Patent Document 2 includes an intake pipe 7 having one end opened below the impeller 3 in the casing 1 and the other end opened to the atmosphere. ing. The intake pipe 7 is set to have an air flow rate smaller than that in FIG.

  The transition of the operation state will be described. When the water level drops from the normal drain operation shown in the state 13-1 and reaches the lower part of the impeller 3, air flows into the casing 1 from the intake pipe 7. As a result, as shown in the state 13-2, an operation for draining water mixed with air (air-water mixed drainage operation) is performed. As the water level decreases, the air inflow from the intake pipe 7 increases, and the flow rate of the drained water decreases accordingly. When the water level drops to the drainage stop water level as shown in state 13-3, the airlock operation is performed. The air lock operation is maintained by a small amount of air supplied through the intake pipe 7, and the hunting operation is not performed. As shown in state 13-4, when the water level recovers to the re-drainage start water level, the air-water mixed drainage operation is started again. As the water level rises, the inflow amount of air from the intake pipe 7 decreases, and the normal drain operation is performed as shown in the state 13-5.

Japanese Patent No. 2516426 (FIG. 1) Japanese Patent No. 3191102 (FIG. 1)

  However, in the case of the vertical shaft pump of Patent Document 1 shown in FIG. 12, an air-water switching valve 8, a water level gauge 9, and a controller that can be electrically opened and closed are necessary to realize the preceding standby operation. The configuration is complicated. Further, the open / close control of the steam / water switching valve 8 may be disabled due to a power failure or the like, and the reliability is not sufficient.

  Further, in the case of the vertical shaft pump of Patent Document 2 shown in FIG. 13, there is no hunting operation state, but in the air / water mixed drainage operation, the amount of air mixed into the water increases as the water level decreases. As the amount of air increases, the vibration generated in the casing increases, which adversely affects the stability and durability of the operation. In other words, in the vertical shaft pump of Patent Document 2, air-water mixed drainage operation is performed under severe conditions.

  Therefore, the present invention provides a highly-precedented stand-by-type vertical shaft pump that has a simple configuration but can perform a stand-by operation without a hunting operation or a severe air-water mixed drainage operation with a large amount of air. The challenge is to do.

In order to solve the above problems, the present invention provides a stand-by-stand vertical pump that operates even when the water level in the water absorption tank is lower than the drainage water level above the impeller in the casing. An air flow path whose other end is open to the atmosphere above the highest water level in the water absorption tank , and a drainage stop water level below a position where one end of the air flow path communicates with the inside of the casing. an air suction portion was found provided at corresponding positions, the a diaphragm mechanism provided in the air passage, the impeller within said said air intake portion and the water level is lowered from around the water surface drainage stop level casing Air is sucked into the lower area to form an air pool, and this air pool is maintained by the air supplied through the air flow path, and the throttle mechanism allows air to enter the casing from the air suction portion. Until they incorporated have to limit the amount of air flowing into the casing through the air passage so that the air reservoir is not formed in the lower region than the impeller of the casing, the air suction unit, said drainage stop level There is provided an advanced standby type vertical shaft pump comprising an air suction hole provided in a casing at a corresponding position and an air suction bell provided outside the casing so as to surround the air suction hole .

  The preceding standby type vertical shaft pump of the present invention has an air pool until one end communicates with the casing below the impeller and the other end is opened to the atmosphere until air is sucked into the casing from the air suction portion. A throttling mechanism is provided for restricting the amount of air flowing into the casing so as not to be formed. Therefore, the amount of air flowing in from the air flow path is small until the water level drops from the drainage water level to the drainage stop water level, and the air / water mixture / drainage operation becomes mild. On the other hand, when the water level drops to the drainage stop water level, a large amount of air is instantaneously sucked into the casing from the air suction part, and an air pool is formed, and air flows into this air pool through the air flow path, Airlock operation is maintained. Therefore, in the preceding standby type vertical shaft pump of the present invention, it is possible to realize the preceding standby operation in which neither the hunting operation nor the severe air / water mixing / draining operation in which the amount of air is mixed is large. In addition, there is no need to provide a water level gauge, an electrically opened / closed air / water switching valve, or a controller for controlling the opening / closing of the air / water switching valve. There is no fear and it has high reliability.

    The air suction portion may be any device that can suck a large amount of air instantaneously from the vicinity of the water surface when the water level drops to the drainage stop water level. For example, the air suction part is a lower end opening of the casing.

  Or the said air suction part is provided with the air suction hole provided in the casing of the position corresponding to the said drainage stop water level, and the air suction bell provided in the outer side of the casing so that the said air suction hole may be surrounded.

  In the preceding standby type vertical shaft pump of the present invention, until one end communicates with the casing below the impeller and the other end is opened to the atmosphere until air is sucked into the casing from the air suction portion. A throttle mechanism that limits the amount of air flowing into the casing so as not to form an air pool is provided, so that it is possible to realize a prior standby operation without a hunting operation or a severe air-water mixed drainage operation in which a large amount of air is mixed. it can. In addition, since it is not necessary to provide a water level gauge, an air / water switching valve, etc., the configuration is simple and the reliability is high.

  Next, an embodiment of the present invention shown in the drawings will be described.

(First Reference Example)
1 and 2 show a first reference example of the present invention.

  A prior standby type vertical shaft pump (hereinafter simply referred to as a vertical shaft pump) 11 of this reference example is for draining water such as rainwater flowing into a water absorption tank 10 of a drainage pump station from an inflow side pipe (not shown) downstream. A casing 12 extending in the vertical direction is provided. The casing 12 is connected to the straight tubular pumping pipe 12a, the pump casing 12b connected to the lower end of the pumping pipe 12a, the suction bell 12c connected to the lower end of the pump casing 12b, and the upper end of the pumping pipe 12a from the vertical direction. A discharge elbow 12d curved in the horizontal direction is provided. A discharge pipe 13 is connected to the discharge elbow 12d. An impeller 14 is disposed in the pump casing 12. A rotating shaft 15 on which the impeller 14 is fixed to the lower end extends in the vertical direction and protrudes outside the casing 12. The upper end side of the casing 12 is connected to a rotational drive mechanism 16 including a motor, a speed reduction mechanism, and the like schematically shown. In the figure, reference numeral 17 denotes a bearing that supports the rotating shaft 16.

  In addition, the vertical shaft pump 11 includes a first pipe (first flow path) 21 and a second pipe (second flow path) 22. One end 21a of the first pipe line 21 communicates with the inside of the casing 12 below the impeller 14 (near the upper end of the suction bell 12c in this reference example), and the other end 21b communicates with the upper part of the discharge elbow 12d. Yes. On the other hand, the second pipeline 22 extends in the vertical direction. One end 22 a of the second pipeline 22 is connected to the first pipeline 21, and the other end 22 a is open to the atmosphere in the water absorption tank 10. The height position of the one end 21a of the first pipe line 21 corresponds to a re-drainage start water level WL3 described later. The other end 21b of the first pipeline 21 needs to be provided at a position where it will not be submerged at the start of the airlock operation described later (see state 2-2 in FIG. 2), and at least higher than the highest water level in the water absorption tank 10. Located above. Further, the other end 22 b of the second conduit 22 must always be open to the atmosphere, and is positioned above the highest water level in the water absorption tank 10.

  In the present reference example, the first pipeline 21 is separated from the casing 12 except for one end 21a and the other end 21b. Further, the second pipeline 22 is also separated from the casing 12. However, a part or all of the first and second pipes 21 and 22 may be disposed in close contact with the outer peripheral portion of the casing 12 or may be integrally formed. Further, the first and second pipes 21 and 22 may be configured by a flow path that is partially or entirely perforated in the casing 12.

  The lower end opening 12e of the suction bell 12c constitutes an air suction portion in the present invention. As will be described later, a large amount of air is instantaneously sucked from the lower end opening 12e of the suction bell 12c, thereby shifting to an air lock operation.

  Next, the transition of the operating state of the vertical shaft pump 11 will be described. First, the process until the pumping by the vertical shaft pump 11 is started will be described. Based on rainfall information, for example, when the vertical shaft pump 11 is started at a standby water level WL1 lower than the lower end opening 12e of the suction bell 12 (the water tank 10 may have no water), the casing 12 includes Since there is no water, the impeller 14 rotates in the air (idling operation). When the water level in the water absorption tank 10 rises and reaches the lower end of the impeller 14, the water in the water absorption tank 10 is sucked up from the lower end opening 12e of the suction bell 12c by the rotation of the impeller 14, and the suction bell 12c, the pump casing 12b, Water is discharged to the discharge pipe 13 through the pumping pipe 12a and the discharge elbow 12d.

  Next, with reference to FIG. 2, the case where the water level in the water absorption tank 10 once decreases after the start of pumping and then increases will be described. As shown in state 2-1, when the water level in the water absorption tank 10 is at the drainage water level WL4 above the impeller 14 in the casing 12, the water sucked into the casing 12 by the rotation of the impeller 14 as described above. Is discharged into the discharge pipe 13 (normal operation). During this normal operation, a very small amount of water drained to the discharge pipe 13 side flows into the other end 21 b of the first pipe line 21. The water that has flowed into the first conduit 21 flows into the casing 12 from one end 21a of the first conduit 21, and into the one end 22a of the second conduit 22, and from the other end 22b to the suction tank 10. Fall into. Therefore, during normal operation, air does not flow into the casing 12 via the first pipe line 21 or the second pipe line 22, and air does not enter the water drained to the discharge pipe 13 side.

  Even if the water level drops from the drainage water level WL4, normal operation is maintained until the drainage stop water level WL2 corresponding to the lower end opening 12e of the suction bell 12c is reached as shown in state 2-2. Accordingly, from the other end 21b of the first flow path 21 to the one end 21a of the first flow path 21 and the other end 22b of the second flow path 22 until the water level drops from the drain water level WL4 to the drainage stop water level WL2. Water flows out and air does not flow into the casing 12.

  As shown in state 2-2, when the water level in the water absorption tank 10 drops to the drainage stop water level WL2, the water level in the region below the impeller 14 in the casing 12 from near the water surface through the lower end opening 12e of the suction bell 12c. A large amount of air is inhaled instantaneously. As a result, as shown in state 2-3, an air reservoir 25 is formed in a region below the impeller 14 in the casing 12, and a water column 26 is formed above the impeller 14 (air lock operation). . During the air lock operation, since water is not drained to the discharge pipe 13 side, water does not flow into the first and second pipes 21 and 22. Therefore, a small amount of air sucked from the other end 22 b of the second pipe line 22 flows into the first pipe line 21 and flows into the air pool 25 through the one end 21 a of the first pipe line 21. By supplying air to the air reservoir 25, the air lock operation is maintained.

  When the water level in the water absorption tank 10 rises from the drainage stop water level WL2 and rises to a position where one end 21a of the first pipe line 21 communicates with the casing 12 (re-drainage start water level) as shown in a state 2-4. Since 21a is closed with water, the inflow of the air through the 1st pipe line 21 stops, and the pumping by the impeller 14 restarts and it becomes a normal drainage operation. As described above, during normal drainage operation, water flows from the other end 21b of the first conduit 21 to the one end 21a of the first conduit 21 and the other end 22b of the second conduit 22, Air does not enter.

  As described above, in the vertical shaft 11 of the first reference example, the other end 21b of the first pipeline 21 is connected to one end of the first pipeline 21 until the water level drops from the drainage water level WL4 to the drainage stop water level WL2. Since water flows out toward 21 a and the other end 22 b of the second pipe line 22, air does not flow into the casing 12. Further, when the water level rises from the drainage stop water level WL2 to the redrainage start water level WL3, the other end 21b of the first pipe line 21 and the other end 22b of the first pipe line 21 and the other end 22b of the second pipe line 22 are changed. Since water flows out, air does not flow into the casing 12. On the other hand, when the water level drops to the drainage stop water level WL2, a large amount of air is sucked into the casing 12 instantaneously from the lower end opening 12e of the suction bell 12c to form an air pool 25, and the second flow path 22 is formed in the air pool 25. Since air flows in from the other end 22b of the first channel 21 through the one end 21a of the first flow path 21, the air lock operation is maintained. Therefore, there are two types of operation states, a normal drain operation and an air lock operation, and it is possible to realize a preliminary standby operation without a hunting operation and an air / water mixed drain operation. In addition, there is no need to provide a water level gauge, an electrically opened / closed air / water switching valve, or a controller for controlling the opening / closing of the air / water switching valve. There is no fear and it has high reliability.

(Second reference example)
3 and 4 show a second reference example of the present invention.

  In the vertical shaft pump 11 of the second reference example, a plurality of air suction holes 31 for communicating the inside and the outside of the casing 12 are provided in the casing 12 (suction bell 12c in this reference example) at a position corresponding to the drainage stop water level WL2. ing. An air suction bell 32 is provided so as to surround the air suction hole 31. In detail, the air suction bell 32 protrudes from the casing 12 slightly above the air suction hole 32 and the cylindrical portion 32a surrounding the portion of the casing 12 provided with the air suction hole 31 with a space therebetween, and its outer peripheral edge. Is provided with an annular portion 32b integrally connected to the upper end of the cylindrical portion 32a. The height position of the lower end opening 32c of the cylindrical portion 32a coincides with the drainage stop water level WL2.

  When the vertical pump 11 is started at a standby water level WL1 lower than the lower end opening 12e of the suction bell 12, since there is no water in the casing 12, the impeller 14 rotates in the air (idling operation), and the water absorption tank 10 When the water level rises and reaches the lower end of the impeller 14, the water sucked up from the lower end opening 12 e of the suction bell 12 c by the rotation of the impeller 14 is drained to the discharge pipe 13.

  Referring to FIG. 4, during normal operation in the state 4-1, water flows from the other end 21 b of the first pipeline 21 toward the one end 21 a of the first pipeline 21 and the other end 22 b of the second pipeline 22. Does not flow into the casing 12. Even if the water level drops from the drainage water level WL4, the normal operation is maintained until the drainage stop water level WL2 corresponding to the lower end opening 32c of the air suction bell 32 is reached as shown in the state 4-2, and the air in the casing 12 is maintained. Does not flow.

  As shown in state 4-2, when the water level in the water absorption tank 10 drops to the drainage stop water level WL2, from the impeller in the casing 12 through the lower end opening 32c of the air suction bell 32 and the air suction hole 31 from near the water surface. Also, a large amount of air is sucked into the lower area instantaneously. As a result, as shown in the state 4-3, the air pool 25 and the water column 26 are formed, and the air lock operation is performed. During the air lock operation, since water is not drained to the discharge pipe 13 side, water does not flow into the first and second pipes 21 and 22, and the first pipe from the other end 22 b of the second pipe 22. Air flows into the air reservoir 25 through the one end 21 a of 21. The air lock operation is maintained by supplying air to the air reservoir 25.

  When the water level in the water absorption tank 10 rises from the drainage stop water level WL2 and reaches the redrainage start water level as shown in the state 4-4, the one end 21a is closed with water, so that the air via the first conduit 21 The inflow is stopped, and the pumping by the impeller 14 is resumed, so that the normal drainage operation is performed. As described above, air does not flow into the casing 12 during normal drainage operation.

  As described above, there are two types of operation states of the vertical shaft pump 11 of the second reference example, the normal drainage operation and the air lock operation, and it is possible to realize the preceding standby operation without the hunting operation and the air / water mixed drainage operation. In addition, it is not necessary to provide a water level gauge or the like, and the configuration is simple, and there is no risk of operation failure due to a power failure or the like, and high reliability is achieved.

  Since the other configuration and operation of the second reference example are the same as those of the first reference example, the same elements are denoted by the same reference numerals and description thereof is omitted.

(First embodiment)
5 and 6 show a first embodiment of the present invention.

  A standby standby vertical pump (hereinafter simply referred to as a vertical pump) 11 of the present embodiment is for draining water such as rainwater flowing into a water absorption tank 10 of a drainage pump station from an inflow side conduit (not shown) to the downstream side. A casing 12 extending in the vertical direction is provided. The casing 12 is connected to the straight tubular pumping pipe 12a, the pump casing 12b connected to the lower end of the pumping pipe 12a, the suction bell 12c connected to the lower end of the pump casing 12b, and the upper end of the pumping pipe 12a from the vertical direction. A discharge elbow 12d curved in the horizontal direction is provided. A discharge pipe 13 is connected to the discharge elbow 12d. An impeller 14 is disposed in the pump casing 12. A rotating shaft 15 on which the impeller 14 is fixed to the lower end extends in the vertical direction and protrudes outside the casing 12. The upper end side of the casing 12 is connected to a rotational drive mechanism 16 including a motor, a speed reduction mechanism, and the like schematically shown. In the figure, reference numeral 17 denotes a bearing that supports the rotating shaft 16.

  The pump 11 includes an intake pipe (air flow path) 51. One end 51 a of the intake pipe 51 communicates with the inside of the casing 12 (in the present embodiment, near the upper end of the suction bell 12 c) below the impeller 14, and the other end 51 b is open to the atmosphere in the water absorption tank 10. . The height position of the one end 51a of the intake pipe 51 corresponds to a re-drainage start water level WL3 described later. The other end 51 b of the intake pipe 51 needs to be open to the atmosphere at all times, and is located above the highest water level in the water absorption tank 10.

  In the present embodiment, the intake pipe 51 is separated from the casing 12 except for one end 51a. However, a part or all of the intake pipe 51 may be disposed in close contact with the outer peripheral portion of the casing 12 or may be integrally formed. In addition, the intake pipe 51 may be configured by a flow path partially or entirely formed in the casing 12.

  The lower end opening 12e of the suction bell 12c constitutes an air suction portion in the present invention. As will be described later, a large amount of air is instantaneously sucked from the lower end opening 12e of the suction bell 12c, thereby shifting to an air lock operation.

  The intake pipe 51 is provided with a throttle mechanism 52. The throttle mechanism 52 is connected to the casing through the intake pipe 51 so that no air pool is formed in a region below the impeller 14 of the casing 12 until air is sucked into the casing 12 from the lower end opening 12e of the suction bell 12c. The amount of air flowing into 12 is limited. The throttle mechanism 52 is made of an orifice provided in the intake pipe 51, for example. Further, the throttle mechanism 52 may be one in which the diameter of the intake pipe 51 is partially reduced. Furthermore, the throttle mechanism 52 may limit the inflow air amount by setting the pipe diameter to a small diameter in the entire intake pipe 51.

  Next, the transition of the operating state of the vertical shaft pump 11 will be described. First, the process until the pumping by the vertical shaft pump 11 is started will be described. Based on rainfall information, for example, when the vertical shaft pump 11 is started at a standby water level WL1 lower than the lower end opening 12e of the suction bell 12 (the water tank 10 may have no water), the casing 12 includes Since there is no water, the impeller 14 rotates in the air (idling operation). When the water level in the water absorption tank 10 rises and reaches the lower end of the impeller 14, the water in the water absorption tank 10 is sucked up from the lower end opening 12e of the suction bell 12c by the rotation of the impeller 14, and the suction bell 12c, the pump casing 12b, Water is discharged to the discharge pipe 13 through the pumping pipe 12a and the discharge elbow 12d.

  Next, with reference to FIG. 6, the case where the water level in the water absorption tank 10 once decreases after the start of pumping and then increases will be described. As shown in state 6-1, when the water level in the water absorption tank 10 is at the drainage water level WL4 above the impeller 14 in the casing 12, the water sucked into the casing 12 by the rotation of the impeller 14 as described above. Is discharged into the discharge pipe 13 (normal operation). During this normal operation, air does not flow into the casing 12 from the intake pipe 51 due to a balance between the dynamic pressure of the water pumped in the casing 12, the head pressure, the atmospheric pressure, and the like.

  As shown in state 6-2, when the water level in the water absorption tank 10 decreases to near the lower end of the impeller 14, the region below the impeller 14 in the casing 12 from the other end 51b of the intake pipe 51 through the one end 51a. Air begins to flow into. As the water level decreases, the amount of air flowing in from the intake pipe 51 increases, and the flow rate of drained water decreases. As shown in state 6-3, when the water level in the water absorption tank 10 is lowered to the drainage stop water level WL2, it is moved from the vicinity of the water surface to the region below the impeller 14 in the casing 12 through the lower end opening 12e of the suction bell 12c. A large amount of air is inhaled instantaneously. As a result, as shown in a state 6-4, an air reservoir 25 is formed in a region below the impeller 14 in the casing 12, and a water column 26 is formed above the impeller 14 (air lock operation). . During the air lock operation, a small amount of air flows into the air reservoir 25 from the other end 51b of the intake pipe 51 through the one end 51a. By supplying air to the air reservoir 25, the air lock operation is maintained.

  When the water level in the water absorption tank 10 rises from the drainage stop water level WL2 and rises to a position where the one end 51a of the intake pipe 51 communicates with the casing 12 (redrainage start water level WL3) as shown in a state 6-4. The pumping will resume. The impeller in the casing 12 passes through the one end 51a from the other end 51b of the intake pipe 51 as shown in the state 6-5 until the water level sufficiently rises as shown in the state 6-6 and the normal drainage operation is performed. Air flows into the area below 14 and the air / water mixed drainage operation is performed. As the water level rises, the amount of air inflow from the intake pipe 51 decreases, and the flow rate of drained water increases.

  In the vertical shaft 11 of the present embodiment, the mixed water drainage operation (state 6-2) is performed from the normal drainage operation (state 6-1) to the air lock operation (state 6-3). Further, the air-water mixed drainage operation (state 6-5) is performed until the air lock operation (state 6-3) returns to the normal drainage operation (state 6-6). However, unlike the conventional vertical shaft pump shown in FIG. 13 which shifts to the air lock operation by the air flowing in from the intake pipe 7 (see states 13-2 and 13-3 in FIG. 13), the vertical pump of the present embodiment. 11, the air lock operation is performed by suction of air from the lower end opening 12e of the suction bell 12c (see states 6-3 and 6-4 in FIG. 6). Therefore, compared with the air / water mixing / draining operation in the conventional vertical pump of FIG. 13 (states 13-2 and 13-4 in FIG. 13), the air / water mixing / draining operation (the state of FIG. 6) in the vertical pump 11 of this embodiment. In 13-2, 6-6), the amount of air mixed into the water is sufficient. In other words, in the vertical pump 11 of the present embodiment, only a slight air / water mixing / draining operation is performed, and vibration generated in the casing 12 during the air / water mixing / draining operation is greatly reduced.

  As described above, in the vertical shaft 11 of the first embodiment, a slight amount of gas is required until the water level drops from the drainage water level WL4 to the drainage stop water level WL2 and until the water level rises from the drainage stop water level WL2 to the drainage water level WL4. It becomes water mixing drainage operation. On the other hand, when the water level drops to the drainage stop water level WL2, a large amount of air is instantaneously sucked into the casing 12 from the lower end opening 12e of the suction bell 12c, and an air pool 25 is formed. Since air flows in from 51a, the air lock operation is maintained. Therefore, there are three types of operation states: normal drainage operation, light air / water mixing / drainage operation, and airlock operation, and it is possible to realize a standby operation without hunting operation and air / water mixing / drainage operation under severe conditions. it can. In addition, there is no need to provide a water level gauge, an electrically opened / closed air / water switching valve, or a controller for controlling the opening / closing of the air / water switching valve. There is no fear and it has high reliability.

(Second Embodiment)
7 and 8 show a second embodiment of the present invention.

  In the vertical shaft pump 11 of the second embodiment, a plurality of air suction holes 61 are provided in the casing 12 (suction bell 12c in this embodiment) at a position corresponding to the drainage stop water level WL2 to allow the inside and the outside of the casing 12 to communicate with each other. ing. An air suction bell 62 is provided so as to surround the air suction hole 61. Specifically, the air suction bell 62 protrudes from the casing 12 slightly above the air suction hole 62 and has a cylindrical portion 62a that surrounds the portion of the casing 12 provided with the air suction hole 61 with a space therebetween. Is provided with an annular portion 62b integrally connected to the upper end of the cylindrical portion 62a. The height position of the lower end opening 32c of the cylindrical portion 62a coincides with the drainage stop water level WL2.

  When the vertical pump 11 is started at a standby water level WL1 lower than the lower end opening 12e of the suction bell 12, since there is no water in the casing 12, the impeller 14 rotates in the air (idling operation), and the water absorption tank 10 When the water level rises and reaches the lower end of the impeller 14, the water sucked up from the lower end opening 12 e of the suction bell 12 c by the rotation of the impeller 14 is drained to the discharge pipe 13.

  Referring to FIG. 8, air does not flow into the casing 12 from the intake pipe 51 during the normal operation in the state 8-1. As shown in state 8-3, a slight air-water mixing operation is performed until the drainage stop water level WL2 corresponding to the lower end opening 32c of the air suction bell 62 is reached (state 8-2).

  As shown in state 8-3, when the water level in the water absorption tank 10 is lowered to the drainage stop water level WL2, it is moved from the vicinity of the water surface to the region below the impeller in the casing 12 through the lower end opening 32c of the air suction bell 62. A large amount of air is inhaled instantaneously. As a result, as shown in the state 8-4, the air pool 25 and the water column 26 are formed, and the air lock operation is performed. During the air lock operation, air flows into the air reservoir 25 through the one end 51a of the intake pipe 51. The air lock operation is maintained by supplying air to the air reservoir 25.

  After the water level in the water absorption tank 10 rises from the drainage stop water level WL2 and reaches the redrainage start water level as shown in the state 8-5, the water level rises sufficiently as shown in the state 8-6, and the normal drainage Until the operation starts, air flows from the other end 51b of the intake pipe 51 into the region below the impeller 14 in the casing 12 through the one end 51a, and a slight air-water mixing and draining operation is performed.

  As described above, there are two types of operation states of the vertical shaft pump 11 of the second embodiment, the normal drainage operation, the slight air / water mixing operation, and the air lock operation, and the hunting operation is also performed under severe conditions. It is possible to realize a prior standby operation. In addition, it is not necessary to provide a water level gauge or the like, and the configuration is simple, and there is no risk of operation failure due to a power failure or the like, and high reliability is achieved.

  Since other configurations and operations of the second embodiment are the same as those of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

(Third embodiment)
9 and 10 show a third embodiment of the present invention.

  In the vertical shaft pump 11 according to the third embodiment, the air suction bell 62 opens upward. Specifically, the air suction bell 62 protrudes from the casing 12 slightly below the air suction hole 32 and a cylindrical portion 62a that surrounds the portion of the casing 12 provided with the air suction hole 61 with a space therebetween. Is provided with an annular portion 62d that is integrally connected to the upper end of the cylindrical portion 32a. The height position of the upper end opening 62e of the cylindrical portion 62a coincides with the drainage stop water level WL2.

  Referring to FIG. 10, as in the first embodiment, a slight air-water mixed drainage operation (state 6-2) from the normal drainage operation (state 6-1) to the air lock operation (state 6-3). It becomes. Further, a slight air-water mixed drainage operation (state 6-5) is performed from the air lock operation (state 6-3) to the normal drainage operation (state 6-6). Therefore, there are three types of operation states: normal drainage operation, light air / water mixing / drainage operation, and airlock operation, and it is possible to realize a standby operation without hunting operation and air / water mixing / drainage operation under severe conditions. it can.

  The air suction from the air suction bell 62 shown in the state 10-3 of FIG. 10 into the casing 12 will be described in detail. When the water level in the water absorption tank 10 becomes slightly lower than the drainage stop water level WL2 (the upper end opening 62e of the air suction bell 62), first, water in the air suction bell 62 is instantaneously sucked into the casing 12 from the air suction 61. . Immediately thereafter, a large amount of air near the water surface is sucked into the casing 12 through the air suction hole 61 from the upper end opening 62e of the air suction bell 62. As described above, in the present embodiment, a small amount of water in the air suction bell 62 is sucked just before the air suction via the air suction bell 62 and the air suction hole 61. By sucking this small amount of water, it is possible to reduce the vibration generated in the casing 12 when shifting to the air lock operation.

  Since other configurations and operations of the third embodiment are the same as those of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

It is sectional drawing which shows the prior | preceding standby type | mold vertical shaft pump which concerns on the 1st reference example of this invention. It is the schematic which shows the transition of the driving | running state of the advance stand-by type vertical pump which concerns on the 1st reference example of this invention. It is sectional drawing which shows the prior | preceding standby type | mold vertical shaft pump which concerns on the 2nd reference example of this invention. It is the schematic which shows the transition of the driving | running state of the prior | preceding standby type | mold vertical shaft pump which concerns on the 2nd reference example of this invention. It is sectional drawing which shows the prior | preceding standby type | mold vertical shaft pump which concerns on 1st Embodiment of this invention. It is the schematic which shows the transition of the driving | running state of the advance stand-by type vertical pump which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the prior | preceding standby type | mold vertical shaft pump which concerns on 2nd Embodiment of this invention. It is the schematic which shows the transition of the driving | running state of the prior | preceding standby type | mold vertical pump which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the prior | preceding standby type | mold vertical pump which concerns on 3rd Embodiment of this invention. It is the schematic which shows the transition of the operating state of the advance stand-by type vertical shaft pump which concerns on 3rd Embodiment of this invention. It is the schematic which shows the transition of the operation state of the conventional vertical shaft pump. It is the schematic which shows the transition of the operation state of the conventional prior | preceding standby type | formula vertical shaft pump. It is the schematic which shows the transition of the operation state of the conventional prior | preceding standby type | formula vertical shaft pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Water absorption tank 11 Advance standby type vertical shaft pump 12 Casing 12a Pumping pipe 12b Pump casing 12c Suction bell 12d Discharge elbow 12e Lower end opening 13 Discharge pipe 14 Impeller 15 Rotating shaft 16 Rotation drive mechanism 17 Bearing 21 1st pipe line (1st line) Flow path)
22 2nd pipe line (2nd flow path)
25 Air pool 26 Water column 31, 61 Air suction hole 32, 62 Air suction bell 32 a, 62 a Cylindrical part 32 b, 62 b, 62 d Annular part 32 c, 62 c Lower end opening 51 Intake pipe (air flow path)
51a one end 51b other end 52 throttling mechanism 62e upper end opening WL1 standby water level WL2 drainage stop water level WL3 re-drainage start water level WL4 drainage water level

Claims (1)

In the stand-by type vertical shaft pump that operates even when the water level in the water absorption tank is lower than the drainage water level above the impeller in the casing,
An air flow path having one end communicating with the casing below the impeller and the other end being open to the atmosphere above the highest water level in the water absorption tank ;
An air suction portion at one end of the air passage is found provided at a position corresponding to the drainage stops water level lower than the position that communicates with the casing,
A throttle mechanism provided in the air flow path,
When the water level drops to the drainage stop water level, the air suction part sucks air from the vicinity of the water surface to the area below the impeller in the casing to form an air pool, and this air pool is supplied via the air flow path. Maintained by the air
The throttle mechanism restricts the amount of air flowing into the casing through the air flow path so that no air pool is formed in a region below the impeller of the casing until air is sucked into the casing from the air suction portion. And
The air suction section includes an air suction hole provided in a casing at a position corresponding to the drainage stop water level, and an air suction bell provided outside the casing so as to surround the air suction hole. Standby vertical pump.

Images