JP2017036717A - Vortex prevention device and pump system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of underwater vortex toward a pump from a bottom part of a water suction tank.SOLUTION: A vortex prevention device is installed in the bottom part of the water suction tank that leads liquid to the pump. This vortex prevention device includes: a movable vortex prevention body provided so as to face a suction port of the pump; and a drive mechanism for driving the vortex prevention body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a vortex prevention device and a pump system.

  Conventionally, pump systems have been used to draw water from rivers. The pump system includes, for example, a horizontal or vertical pump that pumps water, and a suction tank that is connected to a river or the like and guides the water to the pump. In such a pump system, an underwater vortex from the bottom of the suction tank toward the pump may be generated as the pump is driven. When this underwater vortex is generated, air enters the inside of the pump, which causes a reduction in pump efficiency, abnormal noise, vibration, damage, and the like. In order to prevent the underwater vortex from being drawn into the pump, a vortex prevention device such as a cross splitter is provided immediately below the suction port of the pump in the suction tank.

JP 2006-22793 A

  By providing the vortex preventing device at the bottom of the water absorption tank as described above, it is possible to prevent the generation of an underwater vortex at a specific position at the bottom of the water absorption tank. However, the position where the underwater vortex is generated may change depending on the operation point of the pump, the water level of the water absorption tank, the shape of the pump and the water absorption tank, and the like. For this reason, for example, when the pump is operated at a low load and when it is operated at a high load, the position where the underwater vortex is generated is different, and the conventional vortex prevention device cannot sufficiently prevent the generation of the underwater vortex. There was a case.

  The present invention has been made to solve at least a part of the above-described problems, and an object of the present invention is to prevent generation of underwater vortices from the bottom of the water absorption tank toward the pump.

The vortex prevention device of the present invention is a vortex prevention device installed at the bottom of a water absorption tank that guides liquid to a pump. This vortex prevention device includes a movable vortex prevention body provided to face the suction port of the pump, and a drive mechanism that drives the vortex prevention body.
With this configuration, the vortex prevention device of the present invention can move the vortex prevention body to a position where the underwater vortex is generated, and can prevent the generation of the underwater vortex from the bottom of the water absorption tank to the pump. Moreover, the vortex prevention device of the present invention can stir the liquid in the water absorption tank by moving the vortex prevention body, and can prevent the generation of underwater vortices.

The vortex prevention body may have a plurality of vortex prevention plates extending from the bottom of the water absorption tank toward the water surface. The drive mechanism may move the plurality of vortex prevention plates.
If it carries out like this, generation | occurrence | production of underwater vortex can be prevented with a some vortex prevention board.
In this case, the drive mechanism may move the plurality of vortex prevention plates by rotating the vortex prevention body.

The pump system of the present invention includes a vortex prevention device of the present invention, a pump provided with a suction port facing the vortex prevention device, a water absorption tank in which the vortex prevention device is installed and guides fluid to the suction port of the pump, Is provided.
With this configuration, also in the pump system of the present invention, the vortex preventing body can be moved to the position where the underwater vortex is generated, and the generation of the underwater vortex from the bottom of the water absorption tank to the pump can be prevented. Moreover, the pump system of this invention can also stir the liquid in a water absorption tank by moving a vortex prevention body, and can prevent generation | occurrence | production of an underwater vortex.

It is a figure showing the schematic structure of the pump system concerning one embodiment of the present invention. It is a top view which shows the structure outline of the vortex prevention body and base body of this embodiment. It is a side view which shows the structure outline of the vortex prevention body and base body of this embodiment. It is a figure which shows the 1st example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows the 2nd example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows the 3rd example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows the 4th example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows the 5th example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows the 6th example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows the 7th example of the drive of the vortex prevention body by a drive mechanism. It is a figure which shows typically generation | occurrence | production of the underwater vortex in the pump system which is not equipped with a vortex prevention device. It is a top view which shows the structure outline of the vortex prevention body and base body of a modification. It is a side view which shows the structure outline of the vortex prevention body and base body of a modification.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the following description shows an example to the last and is not the meaning which limits the technical scope of this invention to the following embodiment. Moreover, the component which comprises each embodiment can be combined arbitrarily, and is not limited to the combination demonstrated below.

  FIG. 1 is a diagram showing a schematic configuration of a pump system according to an embodiment of the present invention. In FIG. 1, a thick arrow F0 indicates the main flow direction of the liquid W in the water absorption tank 20. As shown in the figure, the pump system 10 of the present embodiment includes a water absorption tank (tank body) 20, a pump 30, and a vortex prevention device 40.

  The water absorption tank 20 forms a flow path communicating with the ocean or a river. As for the water absorption tank 20 of this embodiment, although the bottom part 21a is formed along the horizontal surface, an inclination or a level | step difference may be formed in the bottom part 21a.

  The pump 30 pumps up the liquid W such as water in the water absorption tank 20. The pump 30 of this embodiment is a vertical shaft pump, but a horizontal shaft pump or a submersible pump may be used. The pump 30 is arranged in the vicinity of the end of the water absorption tank 20 so that the suction port 31 a is immersed in the liquid W in the water absorption tank 20. The pump 30 includes a casing 31 having a suction port 31 a, an impeller 32 accommodated in the casing 31, and a rotating shaft 33 coupled to the impeller 32. The rotary shaft 33 of the pump 30 is connected to a drive source (not shown). The pump 30 pumps the liquid W in the water absorption tank 20 from the suction port 31a at the lower end of the casing 31 by rotating the rotating shaft 33 and the impeller 32 with the power from the drive source.

The vortex prevention device 40 is installed at the bottom 21 a of the water absorption tank 20. In FIG. 1, the base body 48 is installed so as to be embedded in the bottom portion 21 a of the water absorption tank 20, but the base body 48 is not limited thereto, and may be installed on the surface of the bottom portion 21 a. The base body 48 should just be fixed to the water absorption tank 20 with an anchor bolt, for example. The vortex prevention device 40 is provided to prevent the underwater vortex from being drawn into the pump 30 from the water absorption tank 20 as the pump 30 is operated. The vortex prevention device 40 includes a vortex prevention body 42 provided to face the suction port 31a of the pump 30,
A base body 48 that supports the vortex prevention body 42 and a drive mechanism 50 that drives the vortex prevention body 42 are provided.

  FIG. 2 is a top view showing a schematic configuration of the vortex preventing body and the base body of the present embodiment. FIG. 3 is a side view showing a schematic configuration of the vortex preventing body and the base body of the present embodiment. As shown in FIGS. 2 and 3, the vortex prevention body 42 of the present embodiment includes a plurality of (for example, four) vortex prevention plates 44 a to 44 d extending from the bottom 21 a of the water absorption tank 20 toward the water surface. The vortex prevention plates 44a to 44d are arranged so as to spread radially from the center and are connected to each other. Moreover, the outer edge part of each vortex prevention board 44a-44d is formed in the taper shape from which the distance from a center becomes short, so that it goes upwards. The plurality of vortex prevention plates 44a to 44d may be integrally formed or may be separately formed and connected. The vortex preventing body 42 is supported on the upper surface of the base body 48. The vortex prevention body 42 is installed in the water absorption tank 20 by fixing the base body 48 to the bottom portion 21a of the water absorption tank 20 with a fixture (not shown) or the like.

  The vortex preventing body 42 is operably supported with respect to the base body 48. That is, the vortex prevention body 42 is movable with respect to the bottom 21 a of the water absorption tank 20. In the present embodiment, the vortex preventing body 42 is configured to be rotatable with respect to the base body 48 about a rotation axis AL that passes through the center of the vortex preventing body 42 and extends in the vertical direction Hd. Further, the vortex preventing body 42 is configured to be movable in the vertical direction Hd and the horizontal direction Ld with respect to the base body 48. However, the vortex prevention body 42 only needs to be movable with respect to the bottom 21a of the water absorption tank 20, and is configured to be capable of only one of rotation, movement in the vertical direction Hd, and movement in the horizontal direction Ld. May be. Further, the movement in the horizontal direction Ld may be configured to be movable on one axis (on a straight line) or may be configured to be movable on two axes (on a plane).

  The vortex prevention body 42 is driven by the drive mechanism 50. As an example of the drive mechanism 50 that rotates the vortex prevention body 42, a motor such as a servo motor or a stepping motor can be used. In addition, as the drive mechanism 50 that moves the vortex prevention body 42 in the vertical direction Hd or the horizontal direction Ld, for example, an air cylinder, a ball screw, a motor, or the like can be used.

  4-7 is a figure which shows an example of the drive of the vortex prevention body by a drive mechanism. 4 to 7 show the rotation angle θ1 around the rotation axis AL of the vortex prevention body 42 with respect to the passage of time with the time T0 as a reference (θ1 = 0). In the present embodiment, the drive mechanism 50 drives the vortex prevention body 42 during the operation of the pump 30. For example, as shown by a solid line or a broken line in FIG. 4, the drive mechanism 50 changes the rotation angle θ <b> 1 of the vortex preventing body 42 at a constant rate during the operation of the pump 30, so that the vortex preventing body 42 is moved relative to the base body 48. Rotate at a constant speed. Alternatively, as shown in FIGS. 5 and 6, the drive mechanism 50 moves the vortex prevention body 42 in the reverse direction every time the vortex prevention body 42 rotates by a predetermined angle θa (for example, 90 degrees, 180 degrees, or 360 degrees). It may be rotated. Here, in the example shown in FIG. 5, the drive mechanism 50 changes the rotation angle θ1 at a constant rate so that the rotation speed of the vortex prevention body 42 is constant. In the example shown in FIG. 6, the drive mechanism 50 changes the rotation angle θ1 of the vortex preventing body 42 into a sine wave so that the vortex preventing body 42 rotates smoothly. Furthermore, as shown in FIG. 7, the drive mechanism 50 may randomly change the rotation angle θ <b> 1 of the vortex prevention body 42 so that the vortex prevention body 42 rotates irregularly.

8-10 is a figure which shows another example of the drive of the vortex prevention body by a drive mechanism. 8 to 10 show the displacement H1 in the vertical direction Hd or the displacement L1 in the horizontal direction Ld of the vortex prevention body 40 with respect to the passage of time (H1 = 0, L1 = 0) with respect to the time T0. . For example, as shown in FIG. 8, the drive mechanism 50 changes at least one of the displacement H1 in the vertical direction Hd and the displacement L1 in the horizontal direction Ld of the vortex prevention body 42 during operation of the pump 30 at a constant rate. The vortex prevention body 42 is reciprocated at a constant speed with respect to the base body 48. Further, as shown in FIG. 9, the drive mechanism 50 may change the displacement H1 in the vertical direction Hd or the displacement L1 in the horizontal direction Ld into a sine wave so that the vortex prevention body 42 can smoothly reciprocate. Further, as shown in FIG. 10, the drive mechanism 50 may randomly change the displacement H1 in the vertical direction Hd or the displacement L1 in the horizontal direction Ld so that the vortex prevention body 42 moves irregularly.

  FIG. 11 is a diagram schematically illustrating the generation of underwater vortices in a pump system that does not include a vortex prevention device. When the pump 30 is operated, the liquid W near the pump 30 rotates with the rotation of the impeller 32, and a swirling flow is formed in the water absorption tank 20. When this swirling flow reaches the bottom 20a of the water absorption tank 20, an underwater vortex S1 containing air is formed, which causes vibration, abnormal noise, damage, and the like of the pump 30. The submerged vortex S1 may be generated at different locations depending on the operating state of the pump 30, the water level of the water absorption tank 20, and the like (see the submerged vortex S2 in FIG. 11). In contrast, in the vortex prevention device 40 of the present embodiment, since the movable vortex prevention body 42 is driven by the drive mechanism 50, the vortex prevention body 42 is moved to a position where the underwater vortex is generated to generate the underwater vortex. Occurrence can be prevented. Further, by periodically or constantly driving the vortex preventing body 42 during operation of the pump 30, the inside of the water absorption tank 20 can be agitated, and the generation of underwater vortices can be prevented.

  FIG. 12 is a side view illustrating a schematic configuration of a vortex preventing body and a base body according to a modification. FIG. 13 is a top view showing a schematic configuration of the vortex preventing body and the base body of the modification. As shown in FIGS. 12 and 13, the vortex prevention body 42 </ b> A of the modified example is supported so as to be operable with respect to the base body 48 in the same manner as the vortex prevention body 42 of the above-described embodiment. The vortex prevention body 42A of the modified example includes vortex prevention plates 45a and 45b extending from the bottom 21a of the water absorption tank 20 toward the water surface. The vortex prevention plate 45a is formed in a long plate shape that is long in the vertical direction H1, and the vortex prevention plate 45b is formed in a long plate shape that is long in the horizontal direction L1. The vortex prevention plates 45a and 45b are connected to each other at the ends. The vortex prevention plate 45b is formed to be shorter as the end opposite to the end connected to the vortex prevention plate 45a is directed upward (water surface side). The vortex prevention plates 45a and 45b may be formed integrally or may be separately formed and connected. Similarly to the vortex prevention body 42 of the above-described embodiment, the vortex prevention body 42A of such a modification is also rotated or moved with respect to the base body 48 by the drive mechanism 50, so that the pump 30 is discharged from the bottom 21a of the water absorption tank 20. The generation of underwater vortices toward the

  In the above-described embodiment, the vortex prevention body 42 includes the plurality of vortex prevention plates 42 a to 42 d extending from the bottom 21 a of the water absorption tank 20 toward the water surface. However, the vortex prevention body is not limited to the one having a plurality of vortex prevention plates, and may be, for example, a conical shape whose diameter gradually decreases from the bottom 21a of the water absorption tank 20 toward the water surface.

  In the above-described embodiment, the vortex prevention body 42 is driven regularly or constantly during operation of the pump 30. However, the pump system 10 may be configured such that the vortex prevention body 42 is driven when a predetermined condition is established. For example, the vortex prevention body 42 may be driven when a command is issued from the user. In addition, when the pump system 10 includes a mechanism for detecting the generation of the underwater vortex in the water absorption tank 20, the vortex prevention body 42 may be driven when the generation of the underwater vortex is detected. In this case, the vortex prevention body 42 may be driven according to the position where the underwater vortex is generated.

Although the embodiments of the present invention have been described above, the above-described embodiments of the present invention are for facilitating the understanding of the present invention and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof. In addition, any combination of the embodiment and the modified example is possible within a range where at least a part of the above-described problems can be solved or a range where at least a part of the effect can be achieved, and is described in the claims and the specification. Any combination or omission of each component is possible.

DESCRIPTION OF SYMBOLS 10 Pump system 20 Water absorption tank 21a Bottom part 30 Pump 40 Eddy prevention apparatus 42, 42A Eddy prevention body 44a-44d, 45a, 45b Eddy prevention board 48 Base body 50 Drive mechanism

Claims (4)

A vortex prevention device installed at the bottom of a water absorption tank that directs liquid to the pump,
A movable vortex preventer provided opposite to the suction port of the pump;
A drive mechanism for driving the vortex preventer;
A vortex prevention device. The vortex prevention device according to claim 1,
The vortex prevention body has a plurality of vortex prevention plates extending from the bottom of the water absorption tank toward the water surface,
The drive mechanism moves the plurality of vortex prevention plates;
Vortex prevention device. The vortex prevention device according to claim 2,
The drive mechanism moves the plurality of vortex prevention plates by rotating the vortex prevention body,
Vortex prevention device. A vortex prevention device according to any one of claims 1 to 3,
A pump provided with a suction port facing the vortex prevention device;
A water absorption tank in which the vortex prevention device is installed and guides fluid to the suction port of the pump;
A pump system comprising.

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