JP7399588B2 - Eddy current suppression device - Google Patents

Description

The present invention relates to a vortex flow suppression device that can suppress the generation of vortex flows when pumping water from a suction water tank.

When pumping water from a suction tank connected to a river or the like, eddy currents may occur within the suction tank. In particular, when the flow velocity in the water tank increases, the pressure of the vortex generated on the floor and walls near the pump decreases, creating a vortex containing air columns (underwater vortex), which may be drawn into the pump. . When air is sucked into the pump due to such an underwater vortex, the density of the water flow changes and the balance is lost, which causes vibrations in the pump and reduces pump efficiency.
When pumping water from a suction tank connected to a river or the like, eddy currents may occur within the suction tank. In particular, when the water level drops due to drainage, a vortex that sucks air from the water surface (air suction vortex) may occur, and this vortex may be drawn into the pump. When air is sucked into the pump by such an air suction vortex, the density of the water flow changes and the balance is lost, causing vibrations in the pump and reducing pump efficiency.

As a countermeasure against this vortex flow, for example, Patent Document 1 describes a vortex flow suppression device in which a vortex flow suppression part is provided at the bottom of a suction water tank and directly below a pump and protrudes from the bottom surface.
Further, Patent Document 2 describes a pump water suction tank in which a plurality of plate-shaped vortex prevention members are disposed opposite to the pump and extend downward from above the water surface in the suction water tank.

Furthermore, Patent Document 3 includes first and second vortex prevention structures each having an arcuate cross section and a curved surface that changes the direction of the flow of liquid in the suction water tank, and a connecting member that connects these structures to each other. A vortex generation prevention device is described. This vortex generation prevention device uses a curved surface to change the direction of the flow of liquid in the suction tank to a different direction, thereby canceling the swirling flow that triggers the generation of vortices and preventing the generation of vortices in the suction tank. It is prevented.

JP 2017-31894 Publication Japanese Patent Application Publication No. 2014-134142 Japanese Patent Application Publication No. 2018-184884

In the above conventional techniques, the following problems remain.
The conventional techniques described in Patent Documents 1 and 2 require civil engineering work to provide equipment for countermeasures against eddy currents in the suction water tank itself, which poses a problem of large scale and increased equipment costs.
In addition, in Patent Document 3, a plurality of vortex prevention structures, each of which is a plate with an arcuate or rectangular cross section, are installed side by side in a suction water tank. There was an inconvenience that this occurred.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a vortex current suppression device that can suppress the generation of vortex currents at low cost.

The present invention employs the following configuration to solve the above problems. That is, the eddy current suppression device according to the first invention is installed around a pump in a suction water tank, and includes a plurality of protrusions and a plate member on which the plurality of protrusions are arranged side by side. It is characterized in that the outer circumferential surface has a circular or elliptical cross section.

This eddy current suppression device includes a plurality of protrusions and a plate member on which the plurality of protrusions are arranged side by side, and the outer peripheral surface of the protrusions has a circular or elliptical cross section, so it resembles a sword mountain. The plurality of protrusions installed on the holder finely cancel out and suppress eddy currents, and since the outer circumferential surfaces of the protrusions are all curved surfaces, it is possible to suppress the generation of new eddy currents. Furthermore, since it has a structure in which a plurality of protrusions are provided on a plate member, it can be easily installed on a wall or floor surface, and can be easily constructed in a short construction period.

In the eddy current suppression device according to a second invention, in the first invention, the plate member includes a plurality of unit length plate parts in which the plurality of protrusions are arranged in an extending direction, and the plurality of unit lengths It is characterized by the plate parts being arranged side by side.
In other words, in this eddy current suppression device, since a plurality of unit long plate parts are arranged side by side, it is possible to easily increase the area by increasing the number of plates according to the installation area, and it has high versatility. There is. Further, since the plate member is divided into a plurality of unit long plate parts, it is only necessary to carry the required number of plate members, and transportation such as carrying in is also facilitated.

The eddy current suppression device according to a third invention is characterized in that, in the second invention, the plurality of unit long plate parts are arranged side by side at intervals.
In other words, in this eddy current suppression device, a plurality of unit long plate parts are arranged side by side with intervals between them, so if the plate members are installed at a distance from an installation surface such as a floor surface, the distance between the unit long plate parts can be reduced. By allowing the sludge to escape below the plate member through the gaps, it is possible to prevent the protrusions from being filled with sludge.

The eddy current suppression device according to a fourth invention is characterized in that, in any one of the first to third inventions, a plurality of plate-side through holes are formed in the plate member.
In other words, in this eddy current suppression device, a plurality of plate-side through holes are formed in the plate member, so if the plate member is installed at a distance from the installation surface such as the floor, sludge will be removed from the plate-side through holes. By passing below the member, it is possible to further prevent sludge from accumulating and filling the protrusion with sludge.

The eddy current suppression device according to a fifth invention is characterized in that, in the fourth invention, a projection-side through hole is formed in the projection portion, communicating with the plate-side through hole and penetrating in the projection direction. shall be.
That is, in this eddy current suppression device, since the protrusion side through-hole is formed in the protrusion part and communicates with the plate-side through-hole and penetrates in the protrusion direction, there is no flow from the protrusion-side through-hole through the plate-side through-hole. By allowing the sludge to escape below the plate member, it is possible to further prevent the protrusion from being filled with sludge. Further, by forming a through hole (a protrusion-side through hole) in the protrusion, it is possible to suppress flapping of the plate member due to fluid resistance.

In the eddy current suppression device according to a sixth invention, in the fourth or fifth invention, the plate member includes a plurality of unit long plate parts in which the plurality of protrusions are arranged in an extending direction, and the plurality of protrusions are arranged in an extending direction. When the unit long plate parts are stacked one above the other, the protrusion part of the lower unit long plate part can be inserted into the plate side through hole and the protrusion side through hole of the upper unit long plate part. It is characterized by being
That is, in this eddy current suppression device, when a plurality of unit long plate parts are stacked one on top of the other, the protrusion of the lower unit long plate part is inserted into the plate side through hole and the protrusion side through hole of the upper unit long plate part. Since it is possible to insert a plurality of unit long plate parts, it is possible to compactly stack a plurality of unit long plate parts, and it becomes possible to easily transport a plurality of unit long plate parts together.

The eddy current suppression device according to a seventh invention is characterized in that, in any one of the first to sixth inventions, the protrusion has a conical shape or a truncated conical shape.
That is, in this eddy current suppressing device, since the protrusion has a conical shape or a truncated conical shape, the tip part has a tapered shape smaller than the base end part, so that the eddy current generated at the tip part can also be suppressed. can.

According to the present invention, the following effects are achieved.
That is, the eddy current suppression device of the present invention includes a plurality of protrusions and a plate member on which the plurality of protrusions are arranged side by side, and the outer peripheral surface of the protrusion has a circular or elliptical cross section. Therefore, the multiple protrusions installed like a sword mountain finely cancel out and suppress the vortices, and the outer peripheral surfaces of the protrusions are all made of curved surfaces, which suppresses the generation of new vortices. can.
Therefore, the eddy current suppression device of the present invention requires no civil engineering work, is low cost, and can prevent the occurrence of vibrations due to eddy currents.

FIG. 1 is a perspective view showing a first embodiment of an eddy current suppression device according to the present invention. FIG. 2 is a cutaway side view showing the suction water tank in which the eddy current suppression device is installed in the first embodiment. In the first embodiment, it is an enlarged sectional view of the main part showing a state in which two unit long plate parts are stacked. FIG. 3 is a perspective view showing a second embodiment of the eddy current suppression device according to the present invention. FIG. 7 is a perspective view showing a state in which an anchor is installed in a second embodiment. FIG. 7 is a perspective view showing a state in which a beam member is attached to an anchor in a second embodiment. It is a perspective view which shows 3rd Embodiment of the eddy current suppression device based on this invention. FIG. 7 is an enlarged perspective view of a main part of an eddy current suppression device in a third embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of the eddy current suppression apparatus in this invention is described based on FIGS. 1-3.

As shown in FIGS. 1 and 2, the eddy current suppression device 1 in this embodiment is installed around a pump P in a suction water tank W, and includes a plurality of protrusions 2 and a plurality of protrusions 2 arranged side by side. A plate member 3 is provided.
The outer peripheral surface of the protrusion 2 has a circular cross section.
Further, the protrusion 2 of this embodiment has a truncated conical shape. That is, the protrusion 2 has a circular cross section (cross section) in a direction perpendicular to the axial direction, and a trapezoidal cross section (vertical cross section) in the axial direction.
The pump P is a so-called vertical shaft pump having a water suction port at the lower end.

A plurality of plate-side through holes 1a are formed in the plate member 3.
The protrusion 2 is formed with a protrusion-side through-hole 2a that communicates with the plate-side through-hole 1a and penetrates in the protruding direction.
Further, the plate member 3 includes a plurality of unit long plate parts 5 in which a plurality of protrusions 2 are arranged side by side in the extending direction, and the plurality of unit long plate parts 5 are arranged side by side.

The plurality of plate-side through holes 1a are formed in a circular shape at intervals in the extending direction of the unit long plate portion 5. Note that the plate-side through hole 1a is set to have an inner diameter that allows the protrusion 2 to be inserted therethrough.
Further, the projections 2 are provided on every other plate-side through-hole 1a of the plate-side through-holes 1a lined up in the unit long plate portion 5.
Further, the plurality of protrusions 2 are arranged in a staggered manner throughout the plate member 3.

The plurality of unit elongated plate portions 5 are arranged side by side in a direction perpendicular to the extending direction with intervals between them.
In this embodiment, a plurality of unit elongated plate parts 5 are placed directly on an installation surface in the suction water tank W, and both ends of each unit elongated plate part 5 are fixed to the installation surface with anchor bolts or the like.
In this embodiment, as shown in FIG. 2, eddy current suppression devices 1 are installed on the floor and wall surfaces of the suction water tank W, respectively.

The unit elongated plate portion 5 and the projection portion 2 are made of, for example, metal such as SUS, rubber, or resin such as plastic.
As shown in FIG. 3, when a plurality of unit long plate parts 5 are stacked vertically, the lower unit length is inserted into the plate side through hole 1a and the protrusion side through hole 2a of the upper unit long plate part 5. The projection 2 of the plate 5 can be inserted.
In FIG. 3, the lower protrusion 2 is inserted into the protrusion side through hole 2a of the upper protrusion 2, but the lower protrusion 2 is inserted into the upper plate side through hole 1a where the protrusion 2 is not provided. It is also possible to insert the section 2 and stack the unit long plate sections 5 one above the other.

In this way, the eddy current suppression device 1 of this embodiment includes a plurality of protrusions 2 and a plate member 3 on which the plurality of protrusions 2 are arranged side by side, and the outer peripheral surface of the protrusion 2 has a circular cross section. Therefore, the plurality of protrusions 2 installed like a sword mountain finely cancel out and suppress the vortices, and since the outer peripheral surface of the protrusions 2 are all curved, the generation of new vortices is also suppressed. can do. Furthermore, since the structure is such that a plurality of protrusions 2 are provided on the plate member 3, it can be easily installed on a wall or floor, and can be easily constructed in a short period of time.

In particular, since a plurality of unit elongated plate parts 5 are arranged side by side, it is possible to easily increase the area by increasing the number of plate parts according to the installation area, and has high versatility. Further, since the plate member 3 is divided into a plurality of unit long plate parts 5, it is only necessary to carry the required number of plate members, and transportation such as carrying in is also facilitated.

Furthermore, when a plurality of unit long plate parts 5 are stacked vertically, the protrusion 2 of the lower unit long plate part 5 is inserted into the plate side through hole 1a and the protrusion side through hole 2a of the upper unit long plate part 5. Since it is possible to insert a plurality of unit long plate parts 5, it is possible to compactly stack a plurality of unit long plate parts 5, and it becomes possible to easily transport a plurality of unit long plate parts 5 together.
Further, since the protrusion 2 has a truncated conical shape, it has a tapered shape in which the distal end is smaller than the proximal end, thereby making it possible to suppress the vortex generated at the distal end.

Next, second and third embodiments of the eddy current suppression device according to the present invention will be described below with reference to FIGS. 4 to 8. In addition, in the following description of each embodiment, the same reference numerals are attached to the same components described in the above embodiment, and the description thereof will be omitted.

The difference between the second embodiment and the first embodiment is that in the first embodiment, a plurality of unit long plate parts 5 are lined up and installed directly on a wall or floor surface, whereas in the second embodiment, the vortex flow In the suppressing device 21, as shown in FIG. 4, the plate member 3 composed of a plurality of unit long plate parts 5 is installed in a state separated from the installation surface such as a wall surface or a floor surface.
That is, in the second embodiment, the plurality of unit elongated plate parts 5 are installed in a floating state from the installation surface, and are arranged at intervals from each other.

To install the eddy current suppression device 21 of the second embodiment on an installation surface, as shown in FIG. 5, anchors 26 are first fixed as scaffolds at the four corners of the eddy current suppression device 21 on the installation surface. These anchors 26 have portions that protrude from the installation surface by a predetermined length. In addition, in the first embodiment, since both ends of each unit long plate part 5 were fixed with anchor bolts, many anchor bolts were required, but in the second embodiment, the anchors 26 are installed at only four locations. Therefore, the number of parts can be reduced.

Next, as shown in FIG. 6, a pair of mutually parallel beam members 27 are used as pedestals to bridge the two anchors 26 and are fixed on the protruding portion of the anchors 26 with bolts and nuts (not shown). . These beam members 27 are installed at predetermined intervals from the installation surface.
Furthermore, as shown in FIG. 4, by fixing a plurality of unit long plate parts 5 on a pair of beam members 27 with bolts and nuts (not shown) so as to span each other at intervals, the eddy current suppression device 21 will be installed.
Note that the anchor 26 and the beam member 27 are made of L-shaped steel or the like.

In this way, in the eddy current suppression device 21 of the second embodiment, the plate member 3 is installed at a distance from the installation surface such as the floor, and the plurality of unit long plate parts 5 are arranged side by side at intervals. Therefore, the sludge escapes below the plate member 3 through the gaps between the unit long plate parts 5, thereby preventing the protrusion parts 2 from being filled with sludge.

Furthermore, by allowing the sludge to escape from the plate-side through-holes 1a below the plate member 3, it is possible to further prevent sludge from accumulating and filling the protrusions 2 with sludge.
Furthermore, since the protrusion side through hole 2a is formed in the protrusion part 2 and communicates with the plate side through hole 1a and penetrates in the protrusion direction, the protrusion side through hole 2a can also be passed through the plate side through hole 1a. By allowing the sludge to escape below the plate member 3, it is possible to further prevent the projections 2 from being filled with sludge.
Further, by forming a through hole (protrusion side through hole 2a) in the protrusion 2, it is possible to suppress flapping of the plate member 3 due to fluid resistance.

Next, the difference between the third embodiment and the second embodiment is that in the second embodiment, a plurality of unit long plate parts 5 are fixed on a pair of beam members 27 with bolts and nuts. In the eddy current suppression device 31 of the third embodiment, as shown in FIGS. 7 and 8, a plurality of unit long plate parts 5 are installed in the gap between a pair of beam members 37 consisting of an inner plate part 37a and an outer plate part 37b. The point is that both ends are inserted and installed in a sliding manner.

That is, in the second embodiment, a gap is provided between the inner plate part 37a and the outer plate part 37b, and the end of the unit long plate part 5 is inserted into this gap, and the inner plate part 37a and the outer plate part By sliding the unit long plate parts 5 in the extending direction of the beam member 37 using the section 37b as a guide, the plurality of unit elongated plate parts 5 are installed side by side in the extending direction of the beam member 37.
Therefore, in the third embodiment, bolts and nuts for fixing the plurality of unit long plate parts 5 are not required, and the number of parts can be further reduced.

Note that the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention.

For example, in each of the embodiments described above, the outer circumferential surface of the protrusion has a circular cross-section, but the protrusion may have an elliptical outer circumferential surface.
Further, in each of the above embodiments, a truncated conical protrusion is used, but a conical protrusion may also be used.

Further, in each of the above embodiments, the plate member is composed of a plurality of unit long plate parts, but the plurality of unit long plate parts may be connected with a flexible material so that it can be rolled or folded for transportation. do not have.
Furthermore, in each of the above embodiments, a hard plate member is used, but a plate member made of a flexible thin sheet-like plate material such as a metal sheet of SUS or aluminum, or a rubber sheet may also be used. In this case, the flexible plate member can be rolled up and transported.

DESCRIPTION OF SYMBOLS 1, 21, 31...Eddy flow suppression device, 1a...Plate side through hole, 2...Protrusion part, 2a...Protrusion side through hole, 3...Plate member, 5, 25...Unit long plate part, P...Pump, W...Suction aquarium

Claims (6)

Installed around the pump in the suction tank,
a plurality of protrusions;
and a plate member in which the plurality of protrusions are arranged side by side,
The outer peripheral surface of the protrusion has a circular or elliptical cross section,
An eddy current suppression device characterized in that a plurality of plate-side through holes are formed in the plate member. The eddy current suppression device according to claim 1,
The protrusion is installed on the plate-side through hole,
An eddy current suppression device characterized in that a protrusion-side through-hole is formed in the protrusion portion and communicates with the plate-side through-hole and penetrates in the protrusion direction. The eddy current suppression device according to claim 2 ,
The plate member includes a plurality of unit long plate parts in which the plurality of protrusions are arranged side by side in an extending direction,
When the plurality of unit long plate parts are stacked vertically, the protrusion of the lower unit long plate part is inserted into the plate side through hole and the protrusion side through hole of the upper unit long plate part. An eddy current suppression device characterized in that it is possible. The eddy current suppression device according to any one of claims 1 to 3,
The plate member includes a plurality of unit long plate parts in which the plurality of protrusions are arranged side by side in an extending direction,
An eddy current suppression device characterized in that the plurality of unit elongated plate portions are arranged side by side. The eddy current suppression device according to claim 4,
An eddy current suppression device characterized in that the plurality of unit elongated plate portions are arranged side by side at intervals. The eddy current suppression device according to any one of claims 1 to 5,
An eddy current suppression device characterized in that the protrusion has a conical shape or a truncated conical shape.

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