JP6621349B2 - pump - Google Patents

Description

  The present invention relates to a pump.

  2. Description of the Related Art Vertical shaft pumps that reduce the wear of submerged bearings by supplying lubricating water to the submerged bearings in the pump casing are known. In the vertical shaft pump of Patent Document 1, an external water source installed in a pump station and a protective pipe in a pump casing are connected by a water supply pipe, and lubricating water from the external water source is supplied by a water supply pump.

Japanese Patent Laid-Open No. 5-157089

  In the vertical shaft pump of Patent Document 1, it is necessary to connect a long water supply pipe to the pump station, and therefore, if a large impact is applied to the pump station due to an earthquake or the like, there is a high possibility that the water pipe will be damaged. In this case, since the lubricating water cannot be supplied to the underwater bearing, when the operation of the vertical shaft pump is started, the underwater bearing is damaged due to wear, and the pump cannot be operated. Even when a non-water-filled bearing is used as the submersible bearing, when pumped water containing a large amount of slurry is fed, abrasive wear occurs in the non-water-filled bearing, so that the pump cannot be operated.

  This invention makes it a subject to provide the pump which can be drive | operated by supplying the purified water isolate | separated from the pumping water discharged | emitted as a lubricating water to an underwater bearing.

The present invention provides a pump casing, a rotating shaft disposed in the pump casing, an impeller coupled to the rotating shaft, and disposed in the pump casing , and rotatably supports the rotating shaft. and water bearing, the pump casing is connected via a branch pipe, a filtering means for filtering a portion of the pumping sucked into the pump casing by the impeller, before Symbol purified water was filtered by the filtering means A pump comprising a water supply means for supplying a gap between a rotary shaft and the underwater bearing through a water supply pipe is provided.

  According to this pump, since the purified water obtained by filtering the pumped water by the filtering means is supplied as lubricating water to the underwater bearing, wear of the underwater bearing can be suppressed. In addition, since the filtering means is branched and connected to the pump casing via the branch pipe, the total length of the water supply pipe may be shorter than when supplying lubricating water from an external water source, and the pipe may be connected only around the pump. That's fine. Therefore, it is possible to prevent the pump from becoming inoperable due to a large impact caused by an earthquake or the like and only the water supply pipe being damaged. In addition, since the incidental equipment can be eliminated, the space for the pump station can be saved and the degree of freedom in design and production can be improved.

  A cyclone separator may be used as the filtering means. According to this aspect, the pumped water is separated into purified water and sewage, the purified water is supplied to the underwater bearing, and the sewage containing slurry and the like is discharged out of the cyclone separator. Since the cyclone separator is not clogged with slurry or the like as compared with a filtering means comprising a filter, the number of times of equipment maintenance and inspection can be reduced.

  The cyclone separator includes a drain pipe that discharges sewage separated from the pumped water. You may arrange | position the front-end | tip of this drainage pipe in the suction water tank in which the suction inlet of the said pump casing is arrange | positioned. According to this aspect, the separated sewage can be drained to the downstream side together with the pumped water by the pump. Therefore, incidental facilities for treating sewage are not necessary.

The first aspect of the present invention further includes a connection provided in the pump casing, extending from a peripheral wall toward the rotating shaft, and having an outer end connected to the water supply pipe and an inner end connected to the gap. And a flow meter that is disposed in the water supply pipe and detects the flow rate of the purified water supplied to the gap, one end connected to the discharge side in the pump casing, and the water supply rather than the flow meter A detection pipe having a second end connected to the water supply pipe on the means side and a detection pipe disposed on the detection pipe, and detects a differential pressure between the purified water supply pressure of the water supply means and the discharge pressure of the pump. A pressure gauge, a water flow rate detected by the flowmeter, and a determination unit that determines an abnormality of the underwater bearing based on the pressure difference detected by the pressure gauge. According to this aspect, the vertical shaft pump can always be operated in a stable state.

The second aspect of the present invention further includes a protective pipe disposed in the pump casing via the holder of the underwater bearing so as to cover the outer periphery of the rotating shaft, and a submerged bearing connected to the water supply pipe. And a recovery pipe connected to the protection pipe on the downstream side in the direction in which the purified water flows, a flowmeter disposed in the recovery pipe and detecting the flow rate of the purified water recovered from the protection pipe, And a determination unit that determines an abnormality of the underwater bearing based on a purified water flow rate detected by a flow meter. According to this aspect, the vertical shaft pump can always be operated in a stable state.

  According to the pump of the present invention, the purified water separated from the pumped water to be discharged is supplied to the underwater bearing as lubricating water. Therefore, if the pump is in an operable state, the steady operation is surely performed without damaging the underwater bearing. it can.

Sectional drawing which shows the pump of 1st Embodiment. The conceptual diagram of the cyclone separator branched and connected to the pump casing. Sectional drawing which shows a 1st underwater bearing. Sectional drawing which shows a 2nd underwater bearing. Sectional drawing which shows the shaft seal part of a pump casing. The graph which shows the relationship between the flow volume by a feed water pump, and the differential pressure | voltage in a pump case. Sectional drawing which shows the pump of 2nd Embodiment. Sectional drawing which shows a 1st underwater bearing. Sectional drawing which shows a 2nd underwater bearing. Sectional drawing which shows the shaft seal part of a pump casing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows a vertical shaft pump 10 according to the first embodiment. The vertical shaft pump 10 includes a pump casing 12, a rotating shaft 20, and an impeller 22, and is arranged so as to hang down on the installation floor 1 of the pump station. The vertical shaft pump 10 of the present embodiment includes submerged bearings 24A and 24B that rotatably support the rotary shaft 20, and by supplying purified water CW separated from a part of the pumped water PW to the submerged bearings 24A and 24B, Wear of the bearings 24A and 24B is reduced.

  The pump casing 12 includes a cylindrical pumping pipe 13, and the pumping pipe 13 is disposed so as to penetrate the installation floor 1 and extend in the suction water tank 2 in the vertical direction. The pumping pipe 13 includes a vane casing 14 on the lower side. Moreover, a trumpet tube 15 in which a suction port 16 is formed is disposed below the vane casing 14. A discharge elbow 17 is disposed at the upper end of the pumping pipe 13, and a discharge pipe 18 is connected to the discharge elbow 17.

  The rotary shaft 20 passes through the discharge elbow 17 and is disposed in the pump casing 12 along the axis of the water pump 13. The lower end of the rotating shaft 20 is disposed in the vane casing 14. The impeller 22 is connected to the lower end of the rotating shaft 20 so as not to be relatively rotatable so as to be positioned in the vane casing 14. The first underwater bearing 24 </ b> A is disposed in the vane casing 14 via the casing hub 27. The second submersible bearing 24 </ b> B is disposed in the pumped water pipe 13 via the bearing holder 28 so as to be positioned between the vane casing 14 and the upper end of the pump casing 12.

  In the vertical shaft pump 10, the impeller 22 is rotated through the rotating shaft 20 by driving of a motor 30 as driving means. By this steady operation, the pumped water PW in the suction water tank 2 is sucked from the suction port 16 at the lower end of the pump casing 12, and this pumped water PW is discharged downstream from the pumped water pipe 13 through the discharge elbow 17 and the discharge pipe 18.

  As the first and second submersible bearings 24A and 24B, it is preferable to use non-water-filled bearings made of ceramics or resin that can perform steady operation even when the supply of lubricating water is cut off. However, even if non-water-filled bearings are used as the underwater bearings 24A and 24B, when the liquid containing a large amount of slurry is drained by the vertical shaft pump 10, since the abrasive wear occurs in the underwater bearings 24A and 24B, lubricating water is supplied. It is preferable. Therefore, the vertical pump 10 of this embodiment is provided with a water injection mechanism described below.

(Details of water injection mechanism)
Referring to FIG. 1, the water injection mechanism includes a cyclone separator 35 that is a filtering means and a water supply pump 44 that is a water supply means for the purified water CW, and a part of the pumped water PW discharged by the vertical shaft pump 10 is taken out and filtered. The (separated) purified water CW is supplied to the underwater bearings 24A and 24B as lubricating water. In the water injection mechanism of the present embodiment, the clean water CW is also supplied to the shaft seal device 53 that seals the through hole 17a of the pump casing 12 through which the rotary shaft 20 passes, so that the wear of the shaft seal device 53 is also suppressed.

  The cyclone separator 35 is branched and connected to the discharge pipe 18 of the pump casing 12 via a branch pipe 32 having an L shape in plan view. Referring also to FIG. 2, the cyclone separator 35 includes a conical container 36 formed of a cylindrical body whose diameter gradually increases from the lower part to the upper part. The upper end opening of the conical container 36 is closed by a lid member 37. A pumping water inlet 38 is opened at the upper periphery of the conical container 36. A branch pipe 32 is connected to the pumping water inlet 38 so as to extend in a direction in contact with the outer periphery of the conical container 36 having a circular shape in plan view. A cylindrical sewage outlet 39 is provided at the lower end of the conical container 36, and a cylindrical purified water outlet 40 is provided at the lid member 37. A drain pipe 42 is connected to the sewage outlet 39. The tip of the drain pipe 42 is disposed in the suction water tank 2 through the installation floor 1.

  A part of the pumped water PW flows into the conical container 36 via the branch pipe 32 during the steady operation of the vertical shaft pump 10. Then, as shown conceptually in FIG. 2, the pumped water PW swirls along the wall surface of the conical container 36 by the pump discharge pressure (see swirl flow RF). Thereby, the pressure near the wall surface of the conical container 36 increases, and the pressure near the central axis of the conical container 36 decreases. Further, in the vicinity of the central axis of the conical container 36, an upward flow UF is generated in the upper part and a downward flow is generated in the lower part.

  The solid matter contained in the pumped water PW is separated from the liquid by centrifugal force due to the swirling flow RF, settles downward while rotating, and is discharged from the waste water outlet 39 to the outside of the conical container 36 as waste water DW. The sewage DW is returned to the suction water tank 2 through the drain pipe 42. Further, the purified water CW from which the solid matter is separated is discharged from the purified water outlet 40 to the outside of the conical container 36 by the upward flow UF. However, a minute solid that does not cause wear in the underwater bearings 24A and 24B may be discharged from the purified water outlet 40 on the upward flow UF.

  Referring to FIG. 1, the water supply pump 44 is disposed in a water supply pipe 46 extending from the purified water outlet 40 to the underwater bearings 24 </ b> A and 24 </ b> B. The water supply pipe 46 is branched on the downstream side (discharge side) of the water supply pump 44 into a first pipe 46a that reaches the first submersible bearing 24A and a second pipe 46b that reaches the second submersible bearing 24B. The first pipe 46 a guides the purified water CW from the outside of the pump casing 12 to the gap between the first underwater bearing 24 </ b> A and the rotary shaft 20. The second pipe 46 b guides the purified water CW from the outside of the pump casing 12 to the gap between the second underwater bearing 24 </ b> B and the rotary shaft 20.

  Referring to FIG. 3, the casing hub 27 includes a substantially cylindrical bearing casing 48A in which the first underwater bearing 24A is disposed. The first underwater bearing 24 </ b> A includes a pair of sliding bodies 25 </ b> A and 25 </ b> A that are arranged at intervals in the axial direction of the rotary shaft 20. Between the sliding bodies 25A and 25A, a water supply part 49A composed of a cylindrical space is formed. The bearing casing 48A is provided with a communication portion 50A including a space communicating with the water supply portion 49A. Referring also to FIG. 1, the casing hub 27 is provided with a connecting portion 51A extending from the peripheral wall of the vane casing 14 toward the rotary shaft 20 and reaching the peripheral wall of the bearing casing 48A. The connecting portion 51A has an inner end connected to the communication portion 50A and an outer end connected to the first piping 46a, thereby connecting the first piping 46a and the communication portion 50A.

  Referring to FIG. 4, the bearing holder 28 includes a substantially cylindrical bearing casing 48B in which the second underwater bearing 24B is disposed. The second underwater bearing 24 </ b> B includes a pair of sliding bodies 25 </ b> B and 25 </ b> B that are arranged at an interval in the axial direction of the rotary shaft 20. A water supply part 49B made of a cylindrical space is formed between the sliding bodies 25B and 25B. The bearing casing 48B is provided with a communication portion 50B formed of a space communicating with the water supply portion 49B. Referring also to FIG. 1, the bearing holder 28 is provided with a connecting portion 51B extending from the peripheral wall of the vane casing 14 toward the rotary shaft 20 and reaching the peripheral wall of the bearing casing 48B. The connecting portion 51B has the inner end connected to the communicating portion 50B and the outer end connected to the second piping 46b, thereby connecting the second piping 46b and the communicating portion 50B.

  Referring to FIG. 5, the shaft seal device 53 includes a shaft seal casing 54 disposed in the through hole 17 a of the discharge elbow 17. A pair of cylindrical labyrinth seals 55, 55 are attached to the inside of the shaft seal casing 54 with an interval in the axial direction of the rotary shaft 20. Between the labyrinth seals 55 and 55, the water supply part 56 which consists of cylindrical space is formed. Further, the shaft seal casing 54 is provided with a connection portion 57 that communicates with the water supply portion 56. Referring to FIG. 1, a third pipe 46 c that is branched on the downstream side of the water supply pump 44 is connected to the connection portion 57.

  Referring to FIG. 1, the vertical shaft pump 10 includes a control device 65 that controls the motor 30 and the water supply pump 44 to execute a steady operation based on a command from an operation panel (not shown). When the water supply pump 44 is driven during the steady operation, the purified water CW separated by the cyclone separator 35 is supplied to the first and second submersible bearings 24A and 24B and to the shaft seal device 53.

  In the first underwater bearing 24A, the purified water CW is supplied at a predetermined pressure from the pipe 46a to the water supply part 49A via the connection part 51A and the communication part 50A. In the second underwater bearing 24B, the purified water CW is supplied at a predetermined pressure from the pipe 46b to the water supply part 49B via the connection part 57B and the communication part 50B. Thus, the purified water CW flows out into the pump casing 12 through a slight gap between the sliding bodies 25A and 25B and the outer peripheral surface of the rotary shaft 20, and is discharged downstream together with the pumped water PW. In the shaft seal device 53, the purified water CW is supplied from the pipe 46c through the connection portion 57 to the water supply portion 56 at a predetermined pressure. Thus, the purified water CW flows out into the pump casing 12 through a slight gap between the labyrinth seals 55, 55 and the outer peripheral surface of the rotary shaft 20, and is discharged downstream together with the pumped water PW.

  Thus, in the vertical shaft pump 10 of this embodiment, since the purified water CW separated by the cyclone separator 35 is supplied to the underwater bearings 24A and 24B, the steady operation can be reliably performed without damaging the underwater bearings 24A and 24B. . Further, since the cyclone separator 35 is branched and connected to the pump casing 12, the total length of the water supply pipe 46 may be shorter than that in the case of supplying lubricating water from an external water source, and the water supply pipe 46 is provided only around the pump. Piping should be done. Therefore, even if a large impact is applied due to an earthquake or the like, it is possible to prevent the vertical shaft pump 10 from becoming inoperable as much as possible by damaging only the water supply pipe 46.

  In addition, since large-scale incidental facilities such as an external water source and a long water supply pipe are not necessary, the space for the pump station can be saved and the degree of freedom in design can be improved. Furthermore, since the cyclone separator 35 is not clogged with slurry or the like as compared with a filtering means made of a filter, the number of maintenance inspections of the equipment can be reduced. Moreover, since the separated sewage DW is returned to the suction water tank 2 and drained to the downstream side together with the pumped water PW by the vertical shaft pump 10, no additional equipment for treating the sewage DW is required.

  In addition, it is preferable to arrange | position the water storage part which can store the predetermined amount of purified water CW between the cyclone separator 35 and the water supply pump 44, and to supply the purified water CW in this storage part with the water supply pump 44. In this way, the stored purified water CW can be supplied between the underwater bearings 24 </ b> A and 24 </ b> B and the rotary shaft 20 by operating only the water supply pump 44 after the end of the steady operation in which the motor 30 is stopped. . Thereby, the submersible bearings 24A and 24B can be washed when the vertical shaft pump 10 is stopped.

  Moreover, the period (life) which can use the vertical shaft pump 10 becomes long by supplying the purified water CW and reducing wear of the underwater bearings 24A and 24B. However, since the underwater bearings 24A and 24B are in sliding contact with the rotary shaft 20, it is impossible to completely eliminate wear. For this reason, the gap between the underwater bearings 24A and 24B and the rotary shaft 20 becomes gradually larger with use. In order to detect such an abnormality in the underwater bearings 24A and 24B, the vertical shaft pump 10 of the present embodiment is provided with a monitoring device described below.

(Details of monitoring device)
Referring to FIG. 1, the monitoring device is the difference between the flow meters 59A and 59B for detecting the flow rate of the purified water CW supplied to the submersible bearings 24A and 24B, and the purified water supply pressure of the feed water pump 44 and the discharge pressure of the vertical shaft pump 10. A differential pressure gauge 61 that detects pressure and a control device 65 that is a determination unit that determines whether there is an abnormality are provided.

  The flow meters 59A and 59B are disposed in the first and second pipes 46a and 46b, respectively. Further, check valves 60A and 60B are disposed on the first and second pipes 46a and 46b on the downstream side of the flow meters 59A and 59B. By opening and closing these check valves 60A and 60B, the corresponding pipes 46a and 46b can be communicated or blocked. A check valve 60C is also disposed in the third pipe 46c.

  The differential pressure gauge 61 is arranged in a detection pipe 62 having one end connected to the pump casing 12 and the other end connected to the water supply pipe 46 on the water supply pump 44 side than the flow meters 59A and 59B. The detection pipe 62 includes a first branch pipe 62 a connected to the pipe 46 a and a second branch pipe 62 b connected to the pipe 46 b, and these are connected to the differential pressure gauge 61.

  When the vertical shaft pump 10 is inspected, the control device 65 controls the motor 30, the water supply pump 44, and the check valves 60A to 60C to execute the inspection operation. Specifically, the check valve 60C is closed, one of the submersible bearings 24A and 24B to be inspected is opened, and the other check valve 60A and 60B is closed. When the inspection of one of the underwater bearings 24A, 24B is completed, the open / close state of the check valves 60A, 60B is switched, and the other underwater bearing 24A, 24B is inspected.

  As described above, the purified water CW supplied from the water supply pump 44 is supplied to the underwater bearings 24A and 24B via the pipes 46a and 46b, and passes through the gap between the sliding bodies 25A and 25B and the outer peripheral surface of the rotary shaft 20. It flows into the pump casing 12 and is discharged to the discharge elbow 17. The flow rate of the purified water CW flowing through the gap between the underwater bearings 24A, 24B and the rotary shaft 20 corresponds to the purified water flow rate flowing through the pipes 46a, 46b detected by the flow meters 59A, 59B. On the other hand, a differential pressure between the purified water supply pressure of the water supply pump 44 and the discharge pressure of the vertical shaft pump 10 is detected by the differential pressure gauge 61.

  There is a relationship as shown in FIG. 6 between the flow rate of the purified water CW detected by the flow meters 59A and 59B and the differential pressure detected by the differential pressure gauge 61. In FIG. 6, a0 indicates the theoretical value of the gap between the sliding bodies 25A, 25B and the rotating shaft 20, a1 indicates the case where the clearance between the sliding bodies 25A, 25B and the rotating shaft 20 is a design value, and a2 indicates the sliding body 25A. , 25B shows a case where the gap between the sliding bodies 25A, 25B and the rotary shaft 20 is expanded to some extent due to wear, and a3 shows the gap between the sliding bodies 25A, 25B and the rotary shaft 20 due to wear of the sliding bodies 25A, 25B. The case where it has expanded to the extent which needs replacement | exchange of 25A, 25B is shown, and a4 has shown the case where the sliding bodies 25A and 25B are damaged.

  When the differential pressure is the same value, there is little wear and the gap between the slide bodies 25A and 25B and the rotary shaft 20 is small, and the gap between the slide bodies 25A and 25B and the rotary shaft 20 is increased due to wear. In the case where becomes larger, the larger the gap, the greater the purified water flow rate. On the contrary, when the purified water flow rate is the same, if the gap is small, the detected value ΔP by the differential pressure gauge 61 is large, and the detected value ΔP by the differential pressure gauge 61 is small as the gap is large.

  The control device 65 serving as a determination unit determines the occurrence of an abnormality in the underwater bearings 24A and 24B based on signals from the flow meters 59A and 59B and the differential pressure gauge 61 during inspection. In the control device 65, the differential pressure value ΔPa in a state that requires preparation for replacement corresponding to a3 in FIG. 6 and the differential pressure value ΔPb in a state that requires replacement corresponding to a4 in FIG. Is remembered as Moreover, the purified water flow rate Ra in a state where preparation for replacement is necessary and the purified water flow rate Rb in a state where replacement is necessary are stored as second determination values. Then, the abnormality of the underwater bearings 24A and 24B is determined by comparing the detection value ΔP obtained by the differential pressure gauge 61 with the determination values ΔPa and ΔPb. Moreover, the abnormality of the underwater bearings 24A and 24B is determined by comparing the detection values R obtained by the flow meters 59A and 59B with the determination values Ra and Rb. In addition, you may determine abnormality by the result of both a differential pressure value and a purified water flow rate, and you may determine abnormality only by one result.

  As described above, in the vertical shaft pump 10 of the present embodiment, the flow meters 59A and 59B that detect the flow rate of purified water supplied to the submersible bearings 24A and 24B, and the differential pressure meter 61 that detects the differential pressure between the water supply pipe 46 and the pump casing 12. , The abnormality of the underwater bearings 24A and 24B can be determined. Then, by replacing the underwater bearings 24A and 24B by determining the abnormality, the steady operation can always be executed in a stable state, and thus the reliability of the vertical pump 10 can be improved. In addition, a branch part may be further provided in the pipes 46a and 46b so that the state of the underwater bearings 24A and 24B can be confirmed from this part through an endoscope.

(Second Embodiment)
FIG. 7 shows a vertical shaft pump 10 according to the second embodiment. This vertical shaft pump 10 is provided with a protective tube 70 covering the outer periphery of the rotary shaft 20 from the lower portion where the impeller 22 is disposed to the upper end of the discharge elbow 17, and the purified water CW is supplied to the three submersible bearings through the protective tube 70. It is different from the first embodiment in that it is supplied to 24A to 24C and the shaft seal device 53. In addition, the same structure as 1st Embodiment attaches | subjects the same code | symbol, and abbreviate | omits detailed description.

(Details of water injection mechanism)
The first underwater bearing 24 </ b> A is disposed in the vane casing 14 via the casing hub 27. The second underwater bearing 24B is disposed in the pumping pipe 13 via the bearing holder 28A so as to be positioned above the vane casing 14. In the present embodiment, the third underwater bearing 24C is disposed in the pumping pipe 13 via the bearing holder 28B so as to be positioned above the second underwater bearing 24B.

  The protective tube 70 includes a first portion 70a extending from the casing hub 27 to the first bearing holder 28A, a second portion 70b extending from the first bearing holder 28A to the second bearing holder 28B, and a second bearing holder 28B. And a third portion 70c extending from the discharge elbow 17 to the through hole 17a. Each part 70a-70c of the protective tube 70 is connected via the bearing holders 28A and 28B.

  Referring to FIG. 8, the casing hub 27 includes a cylindrical sleeve 27a in which the first underwater bearing 24A is disposed. The lower end of the first portion 70a of the protective tube 70 is fixed to the upper end of the sleeve 27a. A mechanical seal 72 is disposed at the lower end of the sleeve 27a. Further, the sleeve 27a is provided with a communication portion 50 that is notched outward from the inner peripheral surface. Further, the casing hub 27 is provided with a connecting portion 51 extending from the peripheral wall of the vane casing 14 toward the rotary shaft 20 and reaching the sleeve 27a. The connection part 51 connects the recovery pipe 80 and the communication part 50 by connecting the inner end to the communication part 50 and connecting the recovery pipe 80 described later to the outer end.

  Referring to FIG. 9, the bearing holders 28 </ b> A and 28 </ b> B are formed of a cylindrical body in which the second and third underwater bearings 24 </ b> B and 24 </ b> C are disposed. In the bearing holder 28A, the upper end of the first portion 70a of the protective tube 70 is fixed to the lower end, and the lower end of the second portion 70b of the protective tube 70 is fixed to the upper end. In the bearing holder 28B, the upper end of the second portion 70b of the protective tube 70 is fixed to the lower end, and the lower end of the third portion 70c of the protective tube 70 is fixed to the upper end.

  Referring to FIG. 10, the shaft seal device 53 includes a shaft seal casing 54 disposed in the through hole 17 a of the discharge elbow 17. The upper end of the third portion 70c of the protective tube 70 is fixed to the inner peripheral portion of the through hole 17a. A mechanical seal 74 is disposed on the shaft seal casing 54. Further, the shaft seal casing 54 is provided with a connection portion 57 to which the water supply pipe 46 is connected so as to be positioned below the mechanical seal 74.

  Referring to FIG. 7, the water supply pump 44 is disposed in the water supply pipe 46 extending from the purified water outlet 40 of the cyclone separator 35 to the connecting portion 57 of the shaft seal device 53. In the water supply pipe 46, a check valve 76 is disposed between the water supply pump 44 and the cyclone separator 35, and a gate valve 78 is disposed between the check valve 76 and the cyclone separator 35.

  When the motor 30 and the water supply pump 44 are driven by the control device 65, the vertical shaft pump 10 supplies the purified water CW separated by the cyclone separator 35 to the submersible bearings 24A to 24C, as in the first embodiment. Do the driving. Specifically, the purified water CW is supplied to the upper end of the protective tube 70 at a predetermined pressure by the water supply pump 44. Then, the purified water CW flows downward from the upper end of the third portion 70c and flows into the second portion 70b through a slight gap between the underwater bearing 24C in the bearing holder 28B and the rotary shaft 20. Subsequently, it flows into the 1st part 70a through the slight clearance gap between the underwater bearing 24B and the rotating shaft 20 in the bearing holder 28A. Subsequently, it flows into the connecting portion 51 through a slight gap between the underwater bearing 24 </ b> A in the casing hub 27 and the rotary shaft 20. Then, it flows out of the pump casing 12 through the connecting portion 51.

  Thus, in the vertical shaft pump 10 of 2nd Embodiment, since the purified water CW isolate | separated by the cyclone separator 35 is supplied to the underwater bearings 24A-24C via the protective tube 70, the effect | action and effect similar to 1st Embodiment are provided. Obtainable. Moreover, since it is the structure which supplies the purified water CW to the protective pipe 70, the purified water CW is supplied to all the underwater bearings 24A-24C with the single water supply pipe 46, and damage to the underwater bearings 24A-24C can be prevented. Therefore, the piping around the vertical shaft pump 10 can be greatly simplified, so that the space for the pump station can be saved.

  In addition, also in the vertical shaft pump 10 of this 2nd Embodiment, in order to detect abnormality of the underwater bearings 24A-24C, the monitoring apparatus is mounted.

(Details of monitoring device)
The monitoring apparatus according to the second embodiment includes a recovery pipe 80 connected to a connection portion 51 located on the outer surface of the vane casing 14. The recovery pipe 80 is connected to the protective pipe 70 via the casing hub 27 on the downstream side in the direction in which the purified water CW flows (downward in FIG. 7) from the underwater bearings 24A to 24C. The recovery pipe 80 is piped from the suction water tank 2 to the installation floor 1, and a flow meter 59 is disposed in this portion. In addition, the downstream side of the flow meter 59 which is the front-end | tip of the collection pipe 80 penetrates the installation floor 1, and is arrange | positioned in the suction water tank 2 again.

  The control device 65 can execute the inspection operation in parallel with the steady operation. In the control device 65 as the determination unit, a purified water flow rate Ra in a state where preparation for replacement is necessary and a purified water flow rate Rb in a state where replacement is necessary are stored as determination values. And the control apparatus 65 can determine abnormality of the underwater bearings 24A-24C by comparing the detection value R by the flow meter 59 with the determination values Ra and Rb.

  In addition, the pump 10 of this invention is not limited to the structure of the said embodiment, A various change is possible.

  For example, the filtering means may use a filter instead of the cyclone separator 35 and may have a configuration that can filter the pumped water. Moreover, the structure which supplies the purified water which filtered a part of pumping water to a submerged bearing is applicable not only to the vertical shaft pump 10, but the horizontal shaft pump which has arrange | positioned the rotating shaft sideways.

DESCRIPTION OF SYMBOLS 1 ... Installation floor 2 ... Suction water tank 10 ... Vertical shaft pump 12 ... Pump casing 13 ... Pumping pipe 14 ... Vane casing 15 ... Trumpet pipe 16 ... Suction port 17 ... Discharge elbow 17a ... Through-hole 18 ... Discharge pipe 20 ... Rotating shaft 22 ... Impeller 24A-24C ... Underwater bearing 25A, 25B ... Sliding body 27 ... Casing hub 27a ... Sleeve 28, 28A, 28B ... Bearing holder 30 ... Motor 32 ... Branch pipe 35 ... Cyclone separator (filtering means)
36 ... Conical container 37 ... Lid member 38 ... Pumping water inlet 39 ... Sewage outlet 40 ... Purified water outlet 42 ... Drain pipe 44 ... Water supply pump (water supply means)
46 ... Water supply pipes 46a to 46c ... Piping 48A, 48B ... Bearing casing 49A, 49B ... Water supply part 50, 50A, 50B ... Communication part 51, 51A, 51B ... Connection part 53 ... Shaft seal device 54 ... Shaft seal casing 55 ... Labyrinth Seal 56 ... Water supply portion 57 ... Connection portion 59, 59A, 59B ... Flow meter 60A-60C ... Check valve 61 ... Differential pressure gauge 62 ... Detection pipe 62a, 62b ... Branch pipe 65 ... Control device 70 ... Protection pipe 70a ... First Part 70b ... Second part 70c ... Third part 72 ... Mechanical seal 74 ... Mechanical seal 76 ... Check valve 78 ... Gate valve 80 ... Recovery pipe

Claims (4)

A pump casing;
A rotating shaft disposed in the pump casing;
An impeller coupled to the rotating shaft;
Is disposed in said pump casing, and water bearing for rotatably supporting the rotary shaft,
Filtration means connected to the pump casing via a branch pipe and filtering a part of the pumped water sucked into the pump casing by the impeller;
A water supply means for supplying via the water supply pipe into the gap of the water bearing the previous SL rotation axis purified water was filtered by said filtration means,
A connecting portion provided in the pump casing, extending from a peripheral wall toward the rotating shaft, and having an outer end connected to the water supply pipe and an inner end communicating with the gap;
A flow meter disposed in the water supply pipe for detecting the flow rate of the purified water supplied to the gap;
A detection pipe having one end connected to the discharge side in the pump casing and the other end connected to the water supply pipe on the water supply means side of the flow meter;
A differential pressure gauge that is disposed in the detection pipe and detects a differential pressure between a purified water supply pressure of the water supply means and a discharge pressure of the pump;
A pump provided with the determination part which determines the abnormality of the said underwater bearing based on the purified water flow detected by the said flow meter, and the differential pressure detected by the said differential pressure gauge .   A pump casing;
  A rotating shaft disposed in the pump casing;
  An impeller coupled to the rotating shaft;
  An underwater bearing disposed in the pump casing and rotatably supporting the rotating shaft;
  A filtering means connected to the pump casing via a branch pipe, and filtering part of the pumped water sucked into the pump casing by the impeller;
  Water supply means for supplying purified water filtered by the filtration means to a gap between the rotary shaft and the underwater bearing through a water supply pipe;
  A protective pipe disposed in the pump casing via the holder of the underwater bearing so as to cover the outer periphery of the rotating shaft, and connected to the water supply pipe;
  A recovery pipe connected to the protection pipe on the downstream side in the direction in which the purified water flows than the underwater bearing;
  A flow meter arranged in the recovery pipe and detecting the flow rate of the purified water recovered from the protective pipe;
  A determination unit for determining an abnormality of the underwater bearing based on a purified water flow rate detected by the flow meter;
  With pump. The pump according to claim 1 or 2 , wherein the filtering means is a cyclone separator. The cyclone separator is provided with a drain pipe for discharging the sewage separated from said pumping, the tip of the drainpipe, the suction port of the pump casing is disposed in the suction water tank disposed in claim 3 The pump described.

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