JP4943737B2 - Vertical shaft pump - Google Patents

Description

  The present invention relates to a vertical shaft pump, and more particularly to a vertical shaft pump for pumping liquid such as river water or drainage.

  FIG. 1 is a schematic view showing a vertical shaft pump that has been subjected to corrosion prevention by a conventional sacrificial anode. As shown in FIG. 1, generally, a vertical shaft pump is installed on a pump installation floor 500 at the upper part of a water tank, and a casing 506 that houses an impeller 504 is suspended via a suspension pipe 502. Such a vertical shaft pump is operated in a state where the impeller 504 and the casing 506 are immersed in water, and wear and corrosion of these members gradually occur with the passage of time of use. As an anti-corrosion measure for the impeller 504 and the casing 506, an anti-corrosion method in which an anti-corrosion current is supplied from an external power source to the vicinity of the anti-corrosion site using an electrode rod, and a sacrificial anode having a base potential is installed near the anti-corrosion site Is adopted.

  Among these anticorrosion methods, the anticorrosion method using the sacrificial anode is to prevent corrosion of the anticorrosion site by utilizing the sacrificial anode, which is installed with a material having a lower potential than the anticorrosion site, corrodes in advance of the anticorrosion site. However, if the sacrificial anode is first corroded and consumed, the subsequent anti-corrosion effect is lost, and a new sacrificial anode needs to be installed. Such a sacrificial anode is usually provided in the vicinity of the anticorrosion site from the viewpoint of anticorrosion efficiency as shown in FIG. 1 (for example, the sacrificial anode 508 is attached to the suction bell mouth portion 506a, and the sacrificial anode 510 is When attaching the sacrificial anode or attaching a new sacrificial anode, drain the water from the water tank and check with an operator inside the water tank. Or you need to check by pulling up the pump. For this reason, there is a problem that it is difficult to replace the sacrificial anode at an appropriate time as well as a heavy maintenance burden. In addition, in the anticorrosion method using the electrode rod and the external power source, it is necessary to inspect and maintain the power supply device and the electrode rod through which an electric current flows. Yes.

  That is, as a method (maintenance management method) for inspecting the sacrificial anode and replacing the sacrificial anode for the vertical shaft pump, there are 1) a method in which the pump is installed, and 2) a method in which the pump is pulled up. . Since the method 1) does not require the pump to be pulled up, the cost is low and the period for inspection and replacement can be shortened. However, with this method, the water in the aquarium must be drained and dried for inspection and replacement, and the water channel is divided for each equipment or pump that must be operated at all times. Cannot be used for equipment that cannot be used. In addition, even when the water in the water tank is drained and dried, the work is performed underground, and there is a problem that the worker's scaffold is unstable and workability is poor.

  In addition, the method 2) is expensive and requires a long time for inspection and replacement. For example, when a vertical shaft pump is lifted using an overhead crane, a mechanical engineer, an operator, a crane operator, and the like who are inspectors are required, and considerable work costs are required for the lifting. Also, lifting and reassembling a heavy pump can be a dangerous operation.

  In addition, the lifting and inspection work requires inspection and maintenance after the lifting, and then undergoes steps of re-installation, centering, and trial operation, and requires a considerable number of days. In addition, depending on the machine, it is necessary to keep the required amount of water drained even at the time of inspection / replacement. However, during the inspection period, the pump being inspected cannot be operated. It is necessary to secure drainage capacity by installing Therefore, when such a temporary pump is not installed, it is impossible to deal with emergency drainage.

  The present invention has been made in view of such problems of the prior art, and easily performs inspection of the sacrificial anode and replacement of the sacrificial anode or electrode rod for anticorrosion while the pump is installed without pulling up the pump. It is an object of the present invention to provide a vertical shaft pump that can perform such a process.

According to one state like the present invention, vertical shaft pump can be easily performed inspection and replacement of sacrificial sacrificial anode sacrificial anode in a state of mounting the pump without raising the pump is provided. This vertical shaft pump has a rotating shaft and an impeller fixed to the rotating shaft. In addition, this vertical shaft pump includes a sacrificial anode for preventing corrosion of the anticorrosion site and a guide device for guiding the sacrificial anode to the vicinity of the anticorrosion site.

According to one reference example of the present invention, there is provided a vertical shaft pump that can easily check and replace the anticorrosion electrode rod while the pump is installed without pulling up the pump. This vertical shaft pump has a rotating shaft and an impeller fixed to the rotating shaft. The vertical shaft pump includes an electrode rod, a power source for supplying an anticorrosion current to the electrode rod, and a guide device for guiding the electrode rod to the vicinity of the anticorrosion site.

  According to the vertical pump according to the present invention, it is possible to easily check and replace the sacrificial sacrificial anode or electrode rod in a state where the pump is installed without pulling up the pump, and improve the maintainability of the pump. Can do.

Hereinafter, embodiments and reference examples of a vertical shaft pump according to the present invention will be described in detail with reference to FIGS. 2 to 7B. In FIG. 2 to FIG. 7B, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 2 is a schematic diagram showing the main part of the vertical shaft pump according to the first embodiment of the present invention. As shown in FIG. 2, the vertical shaft pump 1 is accommodated in a guide casing 14 having a suction bell mouth 10 and a discharge bowl 12, a suspension pipe 16 for suspending the guide casing 14 in a water tank, and the guide casing 14. An impeller 20 and a rotating shaft 22 to which the impeller 20 is fixed are provided.

  The suspension pipe 16 extends downward through an insertion hole 26 formed in the pump installation floor 24 at the upper part of the water tank, and is fixed to the pump installation floor 24 via a pump base 28 provided at the upper end of the suspension pipe 16. ing. The rotating shaft (vertical shaft) 22 extends in the vertical direction through the suspension pipe 16 and the guide casing 14. A pump casing 30 is constituted by the guide casing 14 and the suspension pipe 16. In addition, the floor upper part F above the pump installation floor 24 is an area | region which can be inspected, and the water tank part U below the pump installation floor 24 is an area | region where water is submerged.

  As shown in FIG. 2, the suction bell mouth 10 opens downward, and the upper end of the suction bell mouth 10 is fixed to the lower end of the discharge bowl 12. The impeller 20 is fixed to the lower end of the rotating shaft 22, and the impeller 20 and the rotating shaft 22 rotate integrally. The impeller 20 has a plurality of blades 32, and a plurality of guide vanes 34 are arranged above (the discharge side) the impeller 20. These guide vanes 34 are fixed to the inner peripheral surface of the guide casing 14.

  The rotary shaft 22 is rotatably supported by an underwater bearing 36, an intermediate bearing (not shown), and an outer bearing (not shown). The underwater bearing 36 is accommodated in the discharge bowl 12 and supports the rotary shaft 22 in the vicinity of the impeller 20 so as to be rotatable. The underwater bearing 36, the intermediate bearing, and the outer bearing are so-called sliding bearings or rolling bearings that are in sliding or rolling contact with the rotating shaft 22. The upper end of the rotating shaft 22 is connected to a drive shaft of a prime mover (not shown). When the impeller 20 is rotated via the rotary shaft 22 by this prime mover, water (handling liquid) in the water tank is sucked from the suction bell mouth 10 and passes through the discharge bowl 12 and the suspension pipe 16 to a discharge pipe (not shown). Be transported. During operation of the vertical shaft pump 1, the impeller 20 is located below the water surface.

  Here, a conduit 50 as a guide device for guiding the sacrificial anode 40 for preventing the corrosion of the suction bell mouth 10, which is an anticorrosion site, to the vicinity of the suction bell mouth 10 is installed on the side of the suspension pipe 16. ing. That is, the conduit 50 is disposed beside the suspension pipe 16, the lower end thereof is located in the vicinity of the suction bell mouth 10, and the upper end is located above the pump installation floor 24.

  3A is a longitudinal sectional view of the conduit 50, and FIG. 3B is a bottom view of FIG. 3A. As shown in FIG. 3A, the sacrificial anode 40 is connected to the pulling line 51, and can be pulled up to the pump installation floor 24 by the pulling line 51. In this way, the sacrificial anode 40 is inserted into the conduit 50 from the upper end of the conduit 50, lowered to the vicinity of the lower end of the conduit 50 by the pull-up line 51, and installed in the conduit 50. The pull-up line 51 is made of a material that does not impair the anticorrosion effect of the sacrificial anode 40, such as a wire or fiber having a higher potential than the sacrificial electrode.

  When the sacrificial anode 40 is suspended in the conduit 50, the consumption amount of the sacrificial anode 40 can be detected by measuring the change in the weight of the mass system connected to the pull-up line 51. Alternatively, the sacrificial anode 40 may be pulled up by the pull-up line 51 and the consumption amount of the sacrificial anode 40 may be confirmed directly by visual observation.

  Further, as shown in FIGS. 3A and 3B, a portion of the conduit 50 where the sacrificial anode 40 is disposed serves as a flow path for an anticorrosion current that flows between the sacrificial anode 40 and the anticorrosion site. Openings 52 and 53 are formed. In the illustrated example, an opening 52 is formed on the side surface of the conduit 50, and an opening 53 is formed on the bottom surface of the conduit 50. These openings 52 and 53 may be slit-shaped or mesh-shaped.

  In this embodiment, as shown in FIG. 2, a conduit 150 as a guide device for guiding the sacrificial anode 140 to the side of the suspension pipe 16 is also installed in order to prevent corrosion of the suspension pipe 16. ing. The conduit 150 is attached to a support 60 provided on the side of the suspension tube 16 in a state where the sacrificial anode 140 is accommodated therein, and the attachment portion may be detachable. The sacrificial anode 140 in the conduit 150 is installed in the conduit 150 by a pull-up line 151 in the same manner as the sacrificial anode 40 described above. The pull-up line 151 is made of a material that does not impair the anticorrosion effect of the sacrificial anode 140, such as a wire or fiber having a higher potential than the sacrificial electrode. In addition, an opening 152 serving as a flow path for the anticorrosion current flowing between the sacrificial anode 140 and the anticorrosion site is formed on the side surface of the conduit 150. The opening 152 may be slit-shaped or mesh-shaped.

  Here, instead of the above-described pulling lines 51 and 151, as shown in FIG. 4A, a pulling bar 251 is connected to the sacrificial anode 40 or 140, and the sacrificial anode 40 or 140 is connected to the pulling bar 251. You may support. The pull-up bar 251 is made of a material that does not impair the anticorrosion effect of the sacrificial anode 40 or 140, such as a conductive bar or a plastic bar, which has a higher potential than the sacrificial electrode. In this case, a weight 252 may be disposed on the sacrificial anode 40 or 140. For example, if the reference marker 251a is provided on the upper part of the pull-up bar 251, when the sacrificial anode 40 or 140 is consumed and the weight 252 is lowered, the position of the reference marker 251a of the pull-up bar 251 is also lowered. The consumption amount of the sacrificial anode 40 or 140 can be detected by measuring the position of the reference marker 251a. In this case, if the reference marker 251a is constituted by a plurality of scales, the consumption amount of the sacrificial anode 40 or 140 can be known at a glance.

  Further, in order to prevent scattering when the sacrificial anode 40 or 140 is consumed, a cover 253 covering the sacrificial anode 40 or 140 may be provided as shown in FIG. The cover 253 is formed with a large number of holes (openings) 254 that serve as a flow path for the anticorrosion current flowing between the sacrificial anode 40 or 140 and the anticorrosion site. Further, a weight 255 may be disposed above the cover 253 so that the sacrificial anode 40 or 140 that has become smaller due to wear is not exposed to water flow. The cover 253 may be a bag shape as shown in FIG. 4B, or may be a box-shaped cover 253a as shown in FIG. 4C.

  FIG. 5 is a schematic diagram showing a main part of a vertical shaft pump according to the second embodiment of the present invention. In the present embodiment, a conduit 250 having a bent pipe is provided as a guide device that guides the sacrificial anode to the vicinity of the impeller 20 that is the anticorrosion part. The sacrificial anode thrown into the conduit 250 is composed of a plurality of segmented sacrificial anode pieces or grains 240. In this way, the sacrificial anode is composed of a plurality of subdivided sacrificial anode pieces or grains 240, whereby the conduit 250 as a guide device can be curved, and the sacrificial anode can be attached to any anticorrosion site of the vertical shaft pump. It becomes possible to arrange in the vicinity.

  Further, in this embodiment, a conduit 350 is also provided as a guide device for guiding the sacrificial anode to the vicinity of the suction bell mouth 10 that is the anticorrosion site, but the connection portion 350a of the conduit 350 with the suction bell mouth 10 is The opening area of the conduit 350 is larger than that of the inlet 350b, and is widened toward the suction bell mouth 10. A plurality of sacrificial anode pieces or grains 340 subdivided as sacrificial anodes are also introduced into the conduit 350. Thus, by using a plurality of segmented sacrificial anode pieces or grains 340, the opening area in the vicinity of the anticorrosion site 350a of the conduit 350 can be made larger than that of the inlet port 350b, so that the sacrificial anode 340 is disposed. The area near the anticorrosion site can be increased, and the anticorrosion effect can be improved.

  In this embodiment, the consumption amount of the sacrificial anodes 240 and 340 can be confirmed by inserting a fiberscope or the like into each of the conduits 250 and 350 and observing the inside of the conduits 250 and 350.

FIG. 6 is a schematic view showing a main part of a vertical shaft pump in a reference example of the present invention. In this reference example , an electrode bar 440 is used instead of the sacrificial anode 40 in the first embodiment described above, and an anticorrosion current is supplied to the electrode bar 440 from the external power source 441 via the cable 442. It is like that. The electrode rod 440 is inserted into the conduit 50 from the upper end of the conduit 50, is lowered to the vicinity of the lower end of the conduit 50 by the cable 442, and is suspended in the conduit 50. Similarly, an electrode bar 540 is used in place of the sacrificial anode 140 in the first embodiment, and an anticorrosion current flows from the external power source (not shown) to the electrode bar 540 via the cable 542. It is like that.

  Here, for example, as shown in FIG. 7A, an electrode guide 551 having an inclined surface is provided at the bottom of the conduit 50, and a jig 552 that engages with the inclined surface of the electrode guide 551 is provided on the upper portion of the electrode rod 440. The electrode rod 440 may be positioned by providing and engaging the jig 552 with the electrode guide 551. Further, as shown in FIGS. 7A and 7B, the conduit 50 in the portion where the electrode rod 440 is disposed serves as a flow path for the anticorrosion current flowing between the sacrificial anode 40 and the anticorrosion site. Openings 552 and 553 are formed. In the illustrated example, an opening 552 is formed on the side surface of the conduit 50, and an opening 553 is formed on the bottom surface of the conduit 50. These openings 552 and 553 may be slit-shaped or mesh-shaped.

In each of the above-described embodiments and reference examples , the case where the conduits 50, 150, 250, and 350 have a rectangular cross section has been described. However, the present invention is not limited to this. For example, the cross-sectional shapes of the conduits 50, 150, 250, and 350 may be circular or elliptical.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention may be implemented in various forms within the scope of the technical idea.

It is a schematic diagram which shows the conventional vertical shaft pump. It is a schematic diagram which shows the principal part of the vertical shaft pump in the 1st Embodiment of this invention. 3A is a longitudinal sectional view showing a conduit of the vertical shaft shown in FIG. 2, and FIG. 3B is a bottom view of FIG. 3A. 4A is a longitudinal sectional view showing a first modification of the conduit shown in FIG. 2, FIG. 4B is a longitudinal sectional view showing a second modification, and FIG. 4C is a third modification. It is a cross-sectional view which shows an example. It is a schematic diagram which shows the principal part of the vertical shaft pump in the 2nd Embodiment of this invention. It is a schematic diagram which shows the principal part of the vertical shaft pump in the reference example of this invention. 7A is a longitudinal sectional view showing a conduit of the vertical shaft pump shown in FIG. 6, and FIG. 7B is a bottom view of FIG. 7A.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Suction bell mouth 12 Discharge bowl 14 Guide casing 16 Suspension pipe 20 Impeller 22 Rotating shaft 40,140 Sacrificial anode 50,150,250,350 Conduit 51,151 Pull-up line 52,53,152,552,553 Opening 240 , 340 Sacrificial anode piece or grain 251 Lifting rod 252, 255 Weight 253 Cover 441 External power source 440, 540 Electrode rod 442, 542 Cable 551 Electrode guide 552 Jig

Claims (7)

A vertical shaft pump having a rotating shaft and an impeller fixed to the rotating shaft,
A sacrificial anode to prevent corrosion of the anticorrosion site;
A guide device for guiding the sacrificial anode to the vicinity of the anticorrosion site;
A vertical shaft pump comprising:   The vertical shaft pump according to claim 1, wherein the guide device has an opening serving as a flow path for an anticorrosion current flowing between the sacrificial anode and the anticorrosion site.   The vertical shaft pump according to claim 1, wherein the guide device includes a pulling line or a pulling bar that is connected to the sacrificial anode and can pull the sacrificial anode.   The vertical shaft pump according to claim 1 or 2, wherein the sacrificial anode is composed of a plurality of subdivided sacrificial anode pieces or grains.   The vertical shaft pump according to claim 4, wherein the guide device has an opening area in the vicinity of a position where the sacrificial anode is installed relatively large with respect to the guide portion.   The said guide apparatus has a cover which has the opening part which covers the said sacrificial anode and becomes a flow path of the anticorrosion electric current which flows between the said sacrificial anode and the said anticorrosion site | part. The vertical shaft pump according to one item.   The vertical shaft pump according to any one of claims 1 to 6, wherein the guide device is detachably attached in the vicinity of the anticorrosion site in a state where the sacrificial anode is accommodated therein.

Images