JP6426908B2 - Vertical pump - Google Patents

Description

  The present invention relates to a vertical pump, and more particularly to a vertical pump provided with an anti-vortex device mounted on the upstream side of a bellmouth.

  For example, when using a vertical shaft pump (hereinafter, also simply referred to as a "pump") installed in the intake water channel, change in water level in the intake water channel or specification changes such as increase in flow rate (drainage) at the time of pump renewal As a result of the change of the flow field in the intake channel, separation of the flow may occur, and a suction vortex may be generated starting from the separation point of the flow. If such a vortex is sucked into the pump, it may cause problems such as excessive vibration or performance degradation, which may cause pump damage.

  In order to prevent the generation of the vortices, for example, the level of the bottom of the intake channel is lowered so that the vortices that may be generated near the bottom of the intake channel do not reach the bell pipe as the suction pipe. Further, for example, a vortex prevention device having a baffle formed of a plate having a cross shape or the like is attached under a bell mouth (see Patent Documents 1 and 2).

Unexamined-Japanese-Patent No. 2003-328978 JP, 2013-199940, A

  However, the technique of preventing the generation of the vortex by lowering the level of the bottom of the intake channel will increase the construction cost for construction work for civil engineering work.

  On the other hand, a technique for preventing the generation of a vortex by attaching a baffle having a plate having a cross shape or the like below a bellmouth can prevent swirl flow due to suction immediately below the bellmouth. This makes it possible to prevent the generation of vortices immediately below the bellmouth while reducing the construction period and cost.

  However, if there is a large swirling flow in the entire intake channel due to the shape of the intake channel etc., for example, if the specifications are changed at the time of updating the pump, the flow field in the intake channel changes and intake When the flow swirling in the path strikes against the vortex prevention device and is separated, the vortex prevention device itself may generate a vortex.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to flow not only the generation of vortices directly below the bellmouth but also the flow in the intake channel while suppressing the construction period and cost. It is an object of the present invention to provide a vertical shaft pump capable of suppressing the generation of vortices caused by hitting the device for preventing vortex.

In order to achieve the above-mentioned object, the vertical axis pump according to the present invention comprises an anti-vortex device mounted on the upstream side of the bell mouth, said anti-vortex device being parallel to the central axis of the bell mouth and the center A first baffle comprising a plate passing through an axis, and a radially outer end of the first baffle centered on the central axis, the generation of a vortex due to flow coming off the vortex prevention device possess a suppressing vortex suppressing structure, the said vortex suppressing structure includes a first plate-shaped ribs the central axis surface on the end face of the radially outer centering the baffle is fixed in contact with The rib is fixed perpendicularly to the first baffle .

The vertical axis pump according to the present invention further comprises a vortex prevention device mounted on the upstream side of the bell mouth, the vortex prevention device including a plate parallel to the central axis of the bell mouth and passing through the central axis. A baffle, and a vortex suppression structure provided at an end portion of the first baffle in the radial direction outer side centering on the central axis and suppressing generation of the vortex due to the flow coming off the vortex prevention device; And the vortex suppression structure includes a through hole formed at a radially outer end centering on the central axis of the first baffle .

  According to the present invention, it is possible to suppress not only the generation of vortices immediately below the bellmouth but also the generation of vortices due to the flow swirling in the intake channel hitting the vortex prevention device while suppressing the construction period and cost. A pump can be provided.

It is a schematic longitudinal cross-sectional view of the vertical shaft pump which concerns on 1st Embodiment of this invention. 2 (a) is an enlarged longitudinal sectional view showing the periphery of the anti-vortex device of the vertical pump according to the first embodiment, and FIG. 2 (b) is a sectional view taken along the line IIb-IIb in FIG. 2 (a); 2 (c) is a schematic perspective view of the anti-vortex device shown in FIG. 2 (a). 3 (a) is an enlarged longitudinal sectional view showing the periphery of the anti-vortex device of the vertical pump according to the comparative example, FIG. 3 (b) is a sectional view taken along line IIIb-IIIb in FIG. 3 (a), FIG. c) is a schematic perspective view of the anti-vortex device shown in FIG. 3 (a). 4 (a) is an enlarged vertical sectional view showing the periphery of the anti-vortex device of the vertical pump according to the second embodiment, and FIG. 4 (b) is a sectional view taken along line IVb-IVb in FIG. 4 (a); 4 (c) is a schematic perspective view of the anti-vortex device shown in FIG. 4 (a). 5 (a) is an enlarged vertical sectional view showing the periphery of the anti-vortex device of the vertical shaft pump according to the third embodiment, and FIG. 5 (b) is a sectional view taken along line Vb-Vb in FIG. 5 (a); 5 (c) is a schematic perspective view of the anti-vortex device shown in FIG. 5 (a). 6 (a) is an enlarged longitudinal sectional view showing the periphery of the anti-vortex device of the vertical shaft pump according to the fourth embodiment, and FIG. 6 (b) is a sectional view taken along the line VIb-VIb in FIG. 6 (c) is a schematic perspective view of the anti-vortex device shown in FIG. 6 (a). It is an enlarged longitudinal cross-sectional view which shows the periphery of the anti-eddy device of the vertical axis pump which concerns on the modification of 4th Embodiment. It is an enlarged longitudinal cross-sectional view which shows the periphery of the anti-vortex device of the vertical axis pump which concerns on the other modification of 4th Embodiment. FIG. 9 (a) is an enlarged vertical sectional view showing the periphery of the anti-vortex device of the vertical shaft pump according to the fifth embodiment, and FIG. 9 (b) is a sectional view along line IXb-IXb in FIG. 9 (c) is a schematic perspective view of the anti-vortex device shown in FIG. 9 (a).

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In the drawings shown below, the same members or corresponding members are denoted by the same reference numerals, and redundant description will be appropriately omitted. Also, the size and shape of the members may be schematically represented by deformation or exaggeration for the convenience of description.

First Embodiment
First, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1 is a schematic longitudinal sectional view of a vertical shaft pump 100 according to a first embodiment of the present invention.
As shown in FIG. 1, the vertical axis pump 100 is installed, for example, in the intake channel 1 of a drainage station, and has a rotary shaft 2 along the vertical direction and an impeller (impeller) 3 attached to the lower end of the rotary shaft 2. A bell mouth (suction pipe) 4 disposed on the upstream side of the impeller 3, a casing liner 40 disposed on the shroud side of the impeller 3, and a casing 41 disposed on the downstream side of the impeller 3; Have. Here, in the vertical shaft pump 100, a diagonal flow pump is used which discharges fluid from the impeller 3 in a direction oblique to the rotation shaft 2.

  The vertical shaft pump 100 is disposed downstream of the impeller 3 and has the rotary shaft 2 inserted therethrough, and is connected to the pumping pipe 5 for flowing the fluid vertically upward and to the downstream side of the pumping pipe 5. And a motor 7 such as a motor connected to the upper end of the rotary shaft 2 projecting upward from the discharge bend 6. A drain pipe 8 is connected to the downstream side of the discharge bend 6. The vertical shaft pump 100 is installed in the intake channel 1 so that the flange 9 provided on the discharge bend 6 is supported by the pump installation floor 11 by being inserted into the mounting hole 10 from the suction end side. .

  Then, when the impeller 3 is rotated through the rotary shaft 2 by the drive of the prime mover 7, the water flowing in from the bell mouth 4 is pressurized, passes through the casing 41, and the pumping pipe 5 and the discharge bend 6 and the drainage pipe 8 The water is discharged to a drainage channel (not shown). In FIG. 1, reference numeral 12 denotes the bottom of the intake channel 1.

  The vertical shaft pump 100 of the present embodiment is provided with an anti-vortex device 20 mounted below (upstream) the bell mouth 4.

  2 (a) is an enlarged longitudinal sectional view showing the periphery of the anti-vortex device 20 of the vertical shaft pump 100 according to the first embodiment, and FIG. 2 (b) is a sectional view taken along line IIb-IIb of FIG. 2 (a) FIG. 2 (c) is a schematic perspective view of the anti-vortex device 20 shown in FIG. 2 (a). In addition, the vortex prevention device 20 in FIG. 2A is shown in a side view to facilitate understanding (the same applies to the subsequent drawings).

  As shown in FIG. 2, the anti-vortex device 20 is parallel to the central axis CL of the bell mouth 4, that is, parallel to the suction direction, and has a baffle side plate 21 as a first baffle provided with a plate passing through the central axis CL. Have. That is, the baffle side plate 21 forms a flat plate including the central axis CL. The central axis CL also serves as the central axis of the vortex prevention device 20. Here, the baffle side plate 21 is formed of a cross-shaped plate centered on the central axis CL.

  However, the baffle side plates 21 are not limited to the above-described configuration, and are configured from a plurality of (for example, three) plates extending radially from the central axis CL and arranged at equal angular intervals in the circumferential direction It may be

  Further, the anti-vortex device 20 has a baffle bottom plate 22 as a second baffle attached to the side of the baffle side plate 21 opposite to the bell mouth 4. The baffle bottom plate 22 has a circular plate shape perpendicular to the central axis CL.

  The baffle side plate 21 has a main body portion 211 located on the baffle bottom plate 22 side and a support portion 212 located on the bell mouth 4 side. The support portion 212 extends from the radial outer end centering on the central axis CL in the main body portion 211 toward the bellmouth 4 side. Here, the main body portion 211 and the support portion 212 are integrally formed. The lower end of the main body portion 211 of the baffle side plate 21 is fixed to the baffle bottom plate 22 by welding or the like, and the upper end of the support portion 212 of the baffle side plate 21 is fixed to the annular ring plate connection ring 23 by welding or the like. .

  Then, the connection ring 23 is fixed to the lower end portion of the bell mouth 4 by screwing or the like, whereby the anti-vortex device 20 is attached to the lower side (upstream side) of the bell mouth 4. However, the installation of the connection ring 23 may be omitted, and the upper end of the support portion 212 of the baffle side plate 21 may be directly fixed to the lower end of the bell mouth 4 by welding or the like.

  Furthermore, the vortex prevention device 20 is provided at the radially outer end of the baffle side plate 21 with respect to the central axis CL, and the vortex suppression structure 25 suppresses the generation of the vortex caused by the flow hitting the vortex prevention device 20 and peeling off. have.

  In the first embodiment, the vortex suppression structure 25 is a plate-like rib fixed to the radially outer end surface 213 centered on the central axis CL of the baffle side plate 21, and the flat surface of the rib is the baffle side plate It is fixed to the baffle side plate 21 by welding or the like so as to abut on the end face 213 of the baffle 21. The height dimension, the width dimension, and the thickness dimension in the direction parallel to the central axis CL of the vortex suppression structure 25 can be changed as appropriate. Further, although the vortex suppression structure 25 is configured to be in contact with the baffle bottom plate 22 here, it is not limited thereto, and may be separated via a clearance. The vortex prevention device 20 having the vortex suppression structure 25 has an outer diameter that is approximately the same as or slightly larger than the outer diameter of the bell mouth 4 and can be inserted through the mounting holes 10 provided on the pump installation floor 11 Size.

Next, the operation of the vertical shaft pump 100 configured as described above will be described.
As shown in FIG. 1, when the water level of the suction target water in the intake channel 1 exceeds the lower end of the bell mouth 4 (see water level L1 in FIG. 1) and the bell mouth 4 is sufficiently submerged, the vertical pump 100 When activated, water is sucked from the bell mouth 4 and pressurized by the rotation of the impeller 3, passes through the pumping pipe 5, is discharged through the discharge bend 6, and is sent to the drainage pipe 8.

  Here, when water is sucked from the bellmouth 4 by the rotation of the impeller 3, if there is no swirl prevention device 20, the swirling flow by suction immediately below the bellmouth 4 is the bottom plate 12 directly below the bellmouth 4. It may occur on top. However, according to the present embodiment, the swirling flow due to suction immediately below the bell mouth 4 is suppressed by the baffle side plate 21 formed of the cross-shaped plate of the vortex prevention device 20, and the generation of the vortex immediately below the bell mouth 4 Can be prevented.

Next, with reference to FIGS. 2 and 3, the operation of the vortex prevention device 20 in the case where there is a flow 13 which largely swirls in the entire intake channel 1 due to the shape of the intake channel 1 and the like will be described.
In such a case, for example, when the specification is changed at the time of updating the vertical axis pump 100, the flow field in the intake channel 1 changes, and the flow 13 swirling in the intake channel 1 strikes the antivortex device 20. There is.

  FIG. 3 (a) is an enlarged vertical sectional view showing the periphery of the anti-vortex device 30 of the vertical axis pump 200 according to the comparative example, and FIG. 3 (b) is a sectional view along line IIIb-IIIb in FIG. 3 (a), 3 (c) is a schematic perspective view of the anti-vortex device 30 shown in FIG. 3 (a). The vortex prevention device 30 of the vertical shaft pump 200 according to the comparative example is different from the vortex suppression device 20 of the vertical shaft pump 100 according to the present embodiment in that the vortex suppression structure 25 shown in FIG. Since the other configurations are the same, the description will be omitted.

  As shown in FIG. 3 (b), in the comparative example, the swirl prevention device itself 30 is caused by the flow 13 which swirls largely in the intake water channel 1, peeling off the end face 213 of the baffle side plate 21 of the swirl prevention device 30. Vortex 14 is generated.

  On the other hand, as shown in FIG. 2 (b), in the first embodiment, the flow 13 which largely swirls in the intake water channel 1 does not hit the end surface 213 of the baffle side plate 21 of the anti-vortex device 20. Since the flow direction is changed along the surface of the vortex suppressing structure 25 which is a plate-like rib fixed to 213, the generation of the vortex can be suppressed.

  Moreover, civil engineering work to prevent the generation of vortices, for example, lowering the level of the bottom plate 12 of the intake channel 1 is unnecessary, and the pump can be applied to a bellmouth of an existing pump. It is possible to reduce the construction period at the time of remodeling and renewal of equipment and construction costs.

  As described above, the vertical axis pump 100 according to the present embodiment includes the anti-vortex device 20 mounted on the upstream side of the bell mouth 4, and the anti-vortex device 20 is parallel to the central axis CL of the bell mouth 4 and The baffle side plate 21 having a plate passing through the central axis CL and the radially outer end portion of the baffle side plate 21 centered on the central axis CL are provided, and generation of vortex due to flow coming off the vortex prevention device 20 is suppressed And an eddy suppression structure 25.

  Therefore, according to the present embodiment, not only the generation of vortices directly below the bell mouth 4 but also the vortices caused by the flow 13 swirling in the intake channel 1 hitting the vorticity prevention device 20 while suppressing the construction period and cost. It is possible to provide a vertical pump 100 capable of suppressing the occurrence of

Second Embodiment
Next, with reference to FIG. 4, the second embodiment of the present invention will be described focusing on the points that are different from the first embodiment described above, and the description of the common points will be appropriately omitted.
Fig.4 (a) is an expanded longitudinal cross-sectional view which shows the periphery of the vortex prevention apparatus 20a of the vertical axis pump 100a which concerns on 2nd Embodiment, FIG.4 (b) is sectional drawing in alignment with the IVb-IVb line of Fig.4 (a). FIG. 4 (c) is a schematic perspective view of the anti-vortex device 20a shown in FIG. 4 (a).

The second embodiment is different from the first embodiment in that the vortex blocking device 20a has a vortex suppression structure 25a.
In the second embodiment, the vortex suppression structure 25 a is a columnar body fixed to the end surface 213 on the radially outer side centering on the central axis CL of the baffle side plate 21, and the side surface of the columnar body is the end surface of the baffle side plate 21. It is fixed to the baffle side plate 21 by welding or the like so as to abut on the side wall 213. The height dimension, the diameter dimension, and the thickness dimension in the direction parallel to the central axis CL of the vortex suppression structure 25a can be changed as appropriate. Further, although the vortex suppression structure 25a is configured to be in contact with the baffle bottom plate 22 here, the configuration is not limited to this, and the vortex suppression structure 25a may be separated.

  As shown in FIG. 4 (b), in the second embodiment, the flow 13 which largely swirls in the intake water channel 1 is fixed to the end surface 213 without hitting the end surface 213 of the baffle side plate 21 of the vortex preventing device 20 a. Since the direction of the flow can be changed along the surface of the vortex suppression structure 25a which is a columnar body, the generation of the vortex can be suppressed.

Therefore, also according to the second embodiment, the same function and effect as those of the first embodiment can be obtained.
In addition, although the eddy suppression structure 25a which is a columnar body is exhibiting the cylinder (cylinder) in FIG. 4, it is not limited to this, for example, is exhibiting the triangular prism, the square pole, the cone, the triangular pyramid, and the square pyramid. And may be hollow or solid.

Third Embodiment
Next, with reference to FIG. 5, the third embodiment of the present invention will be described focusing on differences from the above-described first embodiment, and the description of the common points will be appropriately omitted.
FIG. 5 (a) is an enlarged vertical cross-sectional view showing the vicinity of the anti-vortex device 20b of the vertical pump 100b according to the third embodiment, and FIG. 5 (b) is a cross-sectional view taken along line Vb-Vb of FIG. Fig. 5 (c) is a schematic perspective view of the anti-vortex device 20b shown in Fig. 5 (a).

The third embodiment is different from the first embodiment in that the vortex blocking device 20b has a vortex suppression structure 25b.
In the third embodiment, the vortex suppression structure 25 b is a curved curved surface portion formed at the radially outer end centering on the central axis CL of the baffle side plate 21. It is necessary to form the bending direction of the curved surface portion along the direction of the flow 13 after investigating the direction of the flow 13 which largely swirls in the intake channel 1, as shown in FIG. 5 (b). .

As shown in FIG. 5 (b), in the third embodiment, the flow 13 which largely swirls in the intake water channel 1 is a curved surface portion formed at the radially outer end of the baffle side plate 21 of the anti-vortex device 20b. Since the current flows along the surface of the vortex suppression structure 25b and is rectified, the generation of the vortex can be suppressed.
Therefore, also according to the third embodiment, the same function and effect as those of the first embodiment can be obtained.

Fourth Embodiment
Next, with reference to FIG. 6, the fourth embodiment of the present invention will be described focusing on differences from the first embodiment described above, and the description of the common points will be appropriately omitted.
Fig.6 (a) is an expanded longitudinal cross-sectional view which shows the periphery of the anti-eddy device 20c of the vertical axis pump 100c which concerns on 4th Embodiment, FIG.6 (b) is sectional drawing in alignment with the VIb-VIb line of Fig.6 (a). FIG. 6 (c) is a schematic perspective view of the anti-vortex device 20c shown in FIG. 6 (a).

The fourth embodiment is different from the first embodiment in that the vortex blocking device 20c has a vortex suppression structure 25c.
In the fourth embodiment, the vortex suppression structure 25 c is a notch formed on the radially outer end centering on the central axis CL of the baffle side plate 21. The size, shape, and number of the vortex suppression structures 25c can be changed as appropriate.

As shown in FIGS. 6 (b) and 6 (c), in the fourth embodiment, the flow 13 which swirls largely in the intake channel 1 is an end surface 213 on the radially outer side of the baffle side plate 21 of the vortex prevention device 20c. Since various flows such as a flow that is bent and a flow that has passed through the inside of the eddy suppression structure 25c that is a notch cross each other and cancel each other, it is possible to suppress the generation of a vortex.
Therefore, also according to the fourth embodiment, the same function and effect as those of the first embodiment can be obtained.
In addition, although the eddy suppression structure 25c which is a notch is exhibiting circular (semicircle) in FIG. 6, it is not limited to this, for example, may be exhibiting ellipse, a square, a triangle, and a trapezoid . Further, the vortex suppression structure 25 c is preferably formed in the vicinity of the baffle bottom plate 22. In this way, it is possible to suppress vortices that may be generated from the baffle bottom plate 22.

FIG. 7 is an enlarged vertical cross-sectional view showing the periphery of a vortex prevention device 20d of a vertical pump 100d according to a modification of the fourth embodiment. FIG. 8 is an enlarged vertical cross-sectional view showing the periphery of a vortex prevention device 20e of a vertical pump 100e according to another modification of the fourth embodiment.
While the vortex suppression structure 25c of the fourth embodiment shown in FIG. 6 is a notch formed on the radially outer end centering on the central axis CL of the baffle side plate 21, it is shown in FIGS. The vortex suppression structures 25d and 25e according to the modification are through holes.
The same operational effects as those of the fourth embodiment can be achieved by such a modification.
Although the vortex suppression structure 25d has a circular shape in FIG. 7 and the vortex suppression structure 25e has a trapezoidal shape in FIG. 8, the shape of the through hole is not limited to these, and for example, an oval, a square, or a triangle May be presented.

Fifth Embodiment
Next, with reference to FIG. 9, the fifth embodiment of the present invention will be described focusing on differences from the first embodiment described above, and the description of the common points will be omitted as appropriate.
Fig.9 (a) is an expanded longitudinal cross-sectional view which shows the periphery of the anti-eddy device 20f of the vertical axis pump 100f which concerns on 5th Embodiment, FIG.9 (b) is sectional drawing in alignment with the IXb-IXb line of Fig.9 (a). Fig. 9 (c) is a schematic perspective view of the anti-vortex device 20f shown in Fig. 9 (a).

  The fifth embodiment is different from the first embodiment in that the vortex blocking device 20f has a columnar structure 25f that suppresses the generation of a vortex caused by the flow hitting and falling off the vortex blocking device 20f. The columnar structure 25 f is erected on the surface of the baffle bottom plate 22 on the bell mouth 4 side, and here, between the two adjacent plates of the baffle side plate 21 on the baffle bottom plate 22 near the end face 213 of the baffle side plate 21. It is set up near the center of the city.

  In the fifth embodiment, the bottom surface of the columnar structure 25 f is fixed to the surface of the baffle bottom plate 22 by welding or the like. The height dimension, the diameter dimension, and the thickness dimension in the direction parallel to the central axis CL of the columnar structure 25 f can be changed as appropriate.

  As shown in FIG. 9 (b), in the fifth embodiment, a swirl 13 is generated by the flow 13 which swirls largely in the intake water channel 1 contacting the end face 213 of the baffle side plate 21 of the vortex prevention device 20 a. By entering near the center on the baffle bottom plate 22, vortices may be generated. However, the swirling energy of these vortices is blocked by the columnar structure 25 f and dissipated, and as a result, the generation of vortices can be suppressed.

Therefore, also according to the fifth embodiment, the same function and effect as those of the first embodiment can be obtained.
In addition, although the columnar structure 25f presents a cylinder (cylinder) in FIG. 9, it is not limited to this, and may have, for example, a triangular prism, a quadrangular prism, a cone, a triangular pyramid, or a square pyramid. It may be hollow or solid.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to above-described embodiment, A various modified example is included. For example, the above-described embodiments are described in detail to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for part of the configurations of the respective embodiments.

  For example, in the first to fourth embodiments, the baffle bottom plate 22 is not necessarily required, and may be omitted. In addition, the above-described vortex suppression structures 25, 25a to 25e and the columnar structures 25f may be implemented in combination as appropriate.

  In the embodiment described above, the vertical axis pump according to the present invention is applied to a mixed flow pump in which the flow discharged from the impeller 3 is in a conical plane with the rotation axis 2 as an axis. The present invention is not limited, and is applicable to an axial flow pump in which the flow discharged from the impeller 3 is in a cylindrical plane concentric with the rotation axis 2.

4 bellmouth 20, 20a to 20f anti-vortex device 21 baffle side plate (first baffle)
22 baffle bottom plate (second baffle)
25, 25a to 25e Vortex suppression structure 25f Columnar structure 100, 100a to 100f Vertical axis pump 213 End face CL Central axis

Claims (3)

Equipped with an anti-vortex device mounted on the upstream side of the bellmouth,
The vortex prevention device is
A first baffle comprising a plate parallel to and passing through the central axis of the bellmouth;
A vortex suppressing structure that is provided at a radially outer end of the first baffle about the central axis, and suppresses the generation of the vortex caused by the flow hitting the vortex prevention device;
I have a,
The vortex suppression structure includes a plate-like rib whose surface abuts and is fixed to a radially outer end surface of the first baffle centered on the central axis,
The vertical pump according to claim 1, wherein the rib is fixed vertically to the first baffle . Equipped with an anti-vortex device mounted on the upstream side of the bellmouth,
The vortex prevention device is
A first baffle comprising a plate parallel to and passing through the central axis of the bellmouth;
A vortex suppressing structure that is provided at a radially outer end of the first baffle about the central axis, and suppresses the generation of the vortex caused by the flow hitting the vortex prevention device;
I have a,
The vertical axis pump according to claim 1, wherein the vortex suppression structure includes a through hole formed at a radially outer end centering on the central axis of the first baffle . A plate-like second baffle mounted on the side opposite to the bell mouth of the first baffle and perpendicular to the central axis;
A columnar structure which is erected on the surface of the second baffle on the side of the bell mouth, and which suppresses the generation of the vortex due to the flow hitting the vortex prevention device and peeling off;
The vertical shaft pump according to claim 1 or 2 , characterized in that

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