Pump

Abstract

The present invention relates to a pump. This pump includes a vortex suppression structure arranged outside a pump casing. The vortex suppression structure includes a first vortex suppression plate and a second vortex suppression plate arranged along an axial direction of a main shaft.

Description

pump

[0001] The present invention relates to a pump.

[0002] In pumping facilities that drain rivers and sewage, etc., there is a need to lower the water level in the suction tanks of pumping facilities due to uneven settlement over time in inflow channels in areas subject to flood prevention measures upstream.In addition, there is a need to improve the pumping capacity of pumps as a countermeasure against sudden rainfall such as the recent torrential downpours.

[0003] However, as the water level drops (the water surface approaches the suction port), vortices can form on the free surface of the water in the suction tank. When these vortices are drawn into the pump, they become air-entraining vortices, causing air to enter the pump.

[0004] In particular, continuous vortices extending continuously from the water surface to the pump suction port are harmful air-sucking vortices that cause abnormal vibrations in the pump and can lead to pump failure.

[0005] Conventionally, the position of the pump's suction port has been lowered to prevent this air from being sucked in. However, when the suction port is closer to the bottom of the suction tank, underwater vortices are more likely to form from the bottom or side walls of the suction tank. Furthermore, as the pumping capacity of pumps improves, the water flow rate in the suction tank increases, making underwater vortices more likely to form. Underwater vortices that form a cavity at the center of the vortex are particularly harmful. The formation of such harmful underwater vortices can cause the pump to vibrate violently, potentially resulting in breakdown.

[0006] However, lowering the bottom level of the suction sump requires high civil engineering and construction costs. Furthermore, when renovating existing pump equipment, the construction period is long, and it is practically impossible to carry out renovation work, including civil engineering, while the pump equipment is in operation. Furthermore, when the suction port approaches the bottom of the sump, underwater vortices are more likely to occur from the bottom and side walls of the sump.

[0007] JP 2019-105252 A JP 2019-124218 A JP 2019-132150 A JP 2019-132151 A JP 2020-159261 A JP 2020-169626 A

[0008] The role of pumps in lifelines is extremely important, and any situation that interferes with pump operation must be avoided as much as possible. To avoid such situations, the following improvements can be made: (A) Improving the vortex suppression effect, (B) Taking measures to prevent foreign matter (such as dust) from adhering to the vortex suppression member, and (C) Improving the stability of pump operation.

[0009] Increasing the vortex suppression effect is important to enable pump operation at water levels lower than those at which existing technology can operate. However, simply increasing the vortex suppression effect and lowering the intake water level to enable pump operation increases the flow velocity of water approaching the pump, affecting the stability of pump operation. Furthermore, the water flowing into the pump may contain foreign matter, such as debris. In this case, there is a concern that the debris may become entangled in the vortex suppression member, affecting the stability of pump operation. Therefore, it is important to implement each of the above (A), (B), and (C) appropriately.

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a pump that can avoid situations that hinder operation.

[0011] In one aspect, there is provided a pump for pumping water from a suction tank, the pump including a main shaft, an impeller fixed to the main shaft, a pump casing that houses the impeller, and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure including a first vortex suppression plate and a second vortex suppression plate disposed along the axial direction of the main shaft.

[0012] In one aspect, at least one of the first vortex suppression plate and the second vortex suppression plate has a notch formed in a lower end thereof. In one aspect, at least one of the first vortex suppression plate and the second vortex suppression plate has an uneven surface formed thereon. In one aspect, the vortex suppression structure includes a reinforcing member that entirely surrounds at least one of the first vortex suppression plate and the second vortex suppression plate.

[0013] In one aspect, at least one of the first vortex suppression plate and the second vortex suppression plate has through holes formed in a surface thereof. In one aspect, at least one of the first vortex suppression plate and the second vortex suppression plate has a plurality of ribs formed in a surface thereof. In one aspect, at least one of the first vortex suppression plate and the second vortex suppression plate has a shrimp-like shape.

[0014] In one aspect, there is provided a pump for pumping water from a suction tank, the pump comprising: a main shaft; an impeller fixed to the main shaft; a pump casing accommodating the impeller; and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure comprising vortex suppression vanes fixed to a lower portion of a suction bell mouth of the pump casing, the vortex suppression vanes being inclined in an upwardly curved manner toward the center of the suction bell mouth.

[0015] In one aspect, there is provided a pump for pumping water from a suction tank, the pump including a main shaft, an impeller fixed to the main shaft, a pump casing that houses the impeller, and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure including vortex suppression vanes fixed to a lower portion of a suction bell mouth of the pump casing, the vortex suppression vanes having notches formed in their side ends.

[0016] In one aspect, a pump for pumping water from a suction tank is provided, the pump including a main shaft, an impeller fixed to the main shaft, a pump casing that houses the impeller, and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure having a hollow boss portion disposed at the center thereof.

[0017] In one aspect, there is provided a pump for pumping water from a suction tank, the pump including a main shaft, an impeller fixed to the main shaft, a pump casing that houses the impeller, and a vortex suppression structure disposed outside the pump casing, the main shaft extending to below a suction bell mouth of the pump casing, and the vortex suppression structure having a swivel boss portion fixed to the tip of the main shaft.

[0018] In one aspect, a pump for pumping water from a suction tank is provided, the pump including a main shaft, an impeller fixed to the main shaft, a pump casing that houses the impeller, and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure including a curved elongated plate extending along the axial direction of the main shaft.

[0019] In one aspect, there is provided a pump for pumping water from a suction tank, the pump including a main shaft, an impeller fixed to the main shaft, a pump casing that houses the impeller, and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure including a plurality of hollow rods extending along the axial direction of the main shaft, each of the plurality of hollow rods having a plurality of flow holes.

[0020] In one aspect, the vortex suppression structure includes an imaging device that images the plurality of hollow rods, and a control device that determines whether or not foreign matter is attached to each of the plurality of hollow rods based on the imaging data captured by the imaging device.

[0021] In one aspect, there is provided a pump for pumping water from a suction tank, the pump comprising: a main shaft; an impeller fixed to the main shaft; a pump casing accommodating the impeller; and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure comprising vortex suppression vanes disposed below a suction bell mouth of the pump casing, the vortex suppression vanes having a number different from the number of blades on the impeller.

[0022] In one aspect, the vortex suppression structure includes a flange portion to which the vortex suppression vanes are fixed, and the flange portion is removably attached to the suction bell mouth.

[0023] In one aspect, a pump for pumping water from a suction sump is provided, the pump comprising: a main shaft, an impeller fixed to the main shaft, a pump casing housing the impeller, and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure including a control device that reduces the flow rate of water pumped by the pump based on water level data detected by a suction-side water level gauge that detects the water level in the suction sump and a discharge-side water level gauge that detects the water level in the discharge sump.

[0024] In one aspect, there is provided a pump for pumping water from a suction tank, the pump comprising: a main shaft; an impeller fixed to the main shaft; a pump casing accommodating the impeller; and a vortex suppression structure disposed outside the pump casing, the vortex suppression structure comprising a vibrometer attached to the pump casing; and a control device electrically connected to the vibrometer, the control device measuring a vibration value of the pump casing based on vibration data detected by the vibrometer, and reducing a flow rate of water pumped by the pump when the measured vibration value increases to a predetermined threshold value.

[0025] A pump equipped with a vortex suppression structure can avoid situations that would disrupt its operation.

[0026] FIG. 2A is a schematic diagram showing an embodiment of a pump equipped with a vortex suppression device. FIG. 2A is a top view of a first vortex suppression plate (and a second vortex suppression plate). FIG. 2B is a diagram showing another embodiment of the first vortex suppression plate (and a second vortex suppression plate). FIG. 3A is a diagram showing another embodiment of the first vortex suppression plate (and a second vortex suppression plate). FIG. 3B is a diagram showing another embodiment of the first vortex suppression plate (and a second vortex suppression plate). FIG. 3C is a diagram showing another embodiment of the first vortex suppression plate (and a second vortex suppression plate). FIG. 5A is a diagram showing another embodiment of the vortex suppression vanes. FIG. 5B is a diagram showing another embodiment of the vortex suppression vanes. FIG. 5C is a diagram showing another embodiment of the vortex suppression vanes. FIG. 5D is a diagram showing another embodiment of the vortex suppression vanes. FIG. 5E is a diagram showing another embodiment of the vortex suppression vanes. FIG. 7A is a diagram showing another embodiment of the vortex suppression vanes. FIG. 7B is a diagram showing another embodiment of the vortex suppression vanes. FIG. 7C is a diagram showing another embodiment of the vortex suppression blade. FIG. 7D is a diagram showing another embodiment of the vortex suppression blade. FIG. 7E is a diagram showing another embodiment of the vortex suppression blade. FIG. 8A is a diagram showing another embodiment of the vortex suppression blade. FIG. 8B is a diagram showing another embodiment of the vortex suppression blade. FIG. 8C is a diagram showing another embodiment of the vortex suppression blade. FIG. 8D is a diagram showing another embodiment of the vortex suppression blade. FIG. 8E is a diagram showing another embodiment of the vortex suppression blade. A diagram showing another embodiment of the boss portion of the vortex suppression structure. A diagram showing another embodiment of the vortex suppression structure. A diagram showing a curved long plate. A diagram showing another embodiment of the vortex suppression structure. FIG. 13A is a diagram showing another embodiment of the vortex suppression plate. FIG. 13B is a diagram showing another embodiment of the vortex suppression plate. A diagram showing another embodiment of the vortex suppression structure. A diagram showing another embodiment of the vortex suppression structure. A diagram showing a vortex suppression structure equipped with an imaging device. FIG. 17A is a diagram showing the number of blades of the impeller. FIG. 17B is a diagram showing the number of vortex suppression blades. FIG. 17C is a diagram showing a flange portion to which the vortex suppression blades are fixed. Fig. 17D is a diagram showing a flange portion to which vortex suppression vanes are fixed. Fig. 19A is a diagram showing another embodiment of a vortex suppression plate. Fig. 19B is a diagram showing another embodiment of a vortex suppression plate.1A and 1B are diagrams illustrating another embodiment of a vortex suppression structure;

[0027] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, identical or corresponding components are designated by the same reference numerals, and duplicated descriptions will be omitted. In the multiple embodiments described below, the configuration of an embodiment that is not particularly described is the same as that of other embodiments, and therefore duplicated descriptions will be omitted.

[0028] The embodiments described below relate to vertical shaft pumps, but the present invention is not limited to these embodiments and can also be used for horizontal shaft pumps. Furthermore, the present invention can also be used for column pipe type submersible pumps.

[0029] Fig. 1 is a schematic diagram showing one embodiment of a pump equipped with a vortex suppression device. As shown in Fig. 1, the pump P includes a main shaft 1 extending vertically, an impeller 2 fixed to the main shaft 1, a pump casing 10 accommodating the impeller 2, a pump pump pipe 11 connected to the upper end of the pump casing 10, and a discharge bend 12 connected to the upper end of the pump pump pipe 11.

[0030] The pump casing 10 is suspended within the suction tank ST by a lifting pipe 11. The pump casing 10 includes a suction bell mouth 15, an impeller casing 16, and a discharge bowl 17. In one embodiment, the pump casing 10 may further include a lifting pipe 11 and a discharge elbow 12 as its components.

[0031] The upper end of the discharge bowl 17 is connected to the lower end of the lifting pipe 11. The suction bell mouth 15 has a suction port 15a that opens downward. The upper end of the suction bell mouth 15 is connected to the lower end of the impeller casing 16. The impeller 2 is housed in the impeller casing 16 and the discharge bowl 17.

[0032] The pump P includes a suspension pipe 21. The suspension pipe 21 is fixed to the upper end of the pump P. The pump P is provided with a suspension pipe 21. The suspension pipe 21 is fixed to the upper end of the pump P.

[0033] The lifting pipe 11 is fixed to a pump installation floor 20 via a hanging pipe 21. The main shaft 1 extends vertically through the discharge elbow 12, the lifting pipe 21, and the pump casing 10.

[0034] The main shaft 1 protrudes upward from the discharge elbow 12 and is connected to a prime mover (e.g., a motor) (not shown). The prime mover is configured to rotate the main shaft 1 and the impeller 2. When the impeller 2 rotates, water in the suction tank ST is sucked through the suction port 15a of the suction bell mouth 15. As the impeller 2 rotates, the water is transported through the pump casing 10, the lifting pipe 11, and the discharge elbow 12 to the discharge pipe (not shown).

[0035] As described above, in order to avoid situations that would interfere with the operation of pump P, it is important to appropriately implement each of the following: (A) improving the vortex suppression effect, (B) taking measures to prevent foreign matter (e.g., dust) from adhering to the vortex suppression member (i.e., the vortex suppression structure described below), and (C) improving the stability of pump operation.

[0036] Therefore, the pump P is configured to achieve at least one of the above (A) to (C) to avoid situations that would interfere with the operation of the pump P. The structure of the pump P equipped with the vortex suppression structure AS will now be described.

[0037] As shown in Fig. 1, the pump P includes a vortex suppression structure AS arranged outside a pump casing 10. In the embodiment shown in Fig. 1, the vortex suppression structure AS includes a first vortex suppression plate 100 and a second vortex suppression plate 110 arranged in series along the direction of the axis CL of the main shaft 1 (i.e., the vertical direction).

[0038] 2A is a top view of the first vortex suppression plate (and the second vortex suppression plate). In FIG. 2A, the pump P is depicted in cross section. As shown in FIG. 2A, the first vortex suppression plate 100 and the second vortex suppression plate 110 have shapes that smoothly curve along the surface shape of the pump casing 10.

[0039] The first vortex suppression plate 100 and the second vortex suppression plate 110 are each fixed to the pump casing 10 by a plurality of brackets BR, and are disposed downstream of the suction bell mouth 15 in the direction of water flow in the suction sump ST (see FIG. 1). In the embodiment shown in FIG. 1, the first vortex suppression plate 100 is larger than the second vortex suppression plate 110, and is disposed below the second vortex suppression plate 110 in the direction of the axis CL.

[0040] According to this embodiment, the vortex suppression structure AS can suppress the generation of underwater vortices by disrupting the flow of water sucked into the pump P. In particular, because the vortex suppression structure AS includes the first vortex suppression plate 100 and the second vortex suppression plate 110, the vortex suppression structure AS can more reliably suppress the generation of underwater vortices (see (A) above). As a result, the pump P is not affected by underwater vortices, and the stability of pump operation can be improved (see (C) above).

[0041] 2B is a diagram showing another embodiment of the first vortex suppression plate (and the second vortex suppression plate). As shown in FIG. 2B, the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) may have a shrimp-like shape. More specifically, the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) has a shape that is curved at a polygonal (obtuse angle) angle along the surface shape of the pump casing 10.

[0042] The first vortex suppression plate 100 (and / or the second vortex suppression plate 110) having a shrimp-shaped configuration can be manufactured by assembling flat plates by welding, for example. This configuration can alleviate restrictions on the manufacturing location of the first vortex suppression plate 100 (and / or the second vortex suppression plate 110).

[0043] For example, depending on the manufacturing location, it may be difficult to curve the first vortex suppression plate 100 (and / or the second vortex suppression plate 110). Even in such a case, the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) having a shrimp-shaped configuration can be manufactured at a manufacturing location where welding is possible.

[0044] 3A to 3C are diagrams showing other embodiments of the first vortex suppression plate (and the second vortex suppression plate). In the embodiment shown in Fig. 3A to 3C, the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) has notches 111A, 111B, 111C formed in the lower end portion 100a (and / or the lower end portion 110a) thereof and extending in a direction perpendicular to the axis CL.

[0045] In the embodiment shown in Figure 3A, the notches 111A have a wave shape, in the embodiment shown in Figure 3B, the notches 111B have a zigzag shape, and in the embodiment shown in Figure 3C, the notches 111C have a comb-tooth shape.

[0046] By forming the notches 111A, 111B, and 111C having such shapes, the vortex suppression structure AS can more actively disrupt the water flow. As a result, the vortex suppression structure AS can more reliably suppress the generation of underwater vortices (see (A) above), and the pump P can improve its operational stability (see (C) above).

[0047] Fig. 4 is a diagram showing a vortex suppression structure including a plurality of vortex suppression vanes. In the embodiment shown in Fig. 4, the vortex suppression structure AS includes a plurality of vortex suppression vanes 120 fixed to the lower part of the suction bell mouth 15. The vortex suppression vanes 120 are fixed to a boss portion 125 disposed at the center of the suction bell mouth 15 and extend radially outward from the boss portion 125.

[0048] Each of the multiple vortex suppression vanes 120 is inclined in an upward curved shape toward the center (i.e., the boss portion 125) of the suction bell mouth 15. In other words, the lower end portion 120a of each of the multiple vortex suppression vanes 120 is inclined in an arc shape.

[0049] This shape allows the vortex suppression structure AS to more actively disrupt the water flow. As a result, the vortex suppression structure AS can more reliably suppress the generation of underwater vortices (see (A) above), and the pump P can improve its operational stability (see (C) above). Furthermore, this shape allows debris to flow smoothly toward the impeller 2 without becoming entangled in the vortex suppression blades 120 (see (B) above).

[0050] 5A to 5E are diagrams showing other embodiments of the vortex suppression vane. The vortex suppression vane 120 has a side end 120b connected to a bottom end 120a. In the embodiment shown in Fig. 5A, the vortex suppression vane 120 has a U-shaped notch 121A formed in the side end 120b.

[0051] In the embodiment shown in Fig. 5B, the vortex suppression vane 120 has a notch 121A and a plurality of holes H formed on the surface of the vortex suppression vane 120. In the embodiment shown in Fig. 5C, the vortex suppression vane 120 has a notch 121B having a comb-tooth shape.

[0052] In the embodiment shown in Figure 5D, the vortex suppression vanes 120 have notches 121C with a zigzag shape. In the embodiment shown in Figure 5E, the vortex suppression vanes 120 have notches 121D with a wave shape.

[0053] These notches 121B, 121C, and 121D extend along the direction of the axis CL. By forming such notches 121A, 121B, 121C, and 121D, the vortex suppression structure AS can more actively disrupt the flow of water. Furthermore, by forming holes H on the surface of the vortex suppression vane 120, the water flow can be more actively disrupted. The holes H may be formed in the vortex suppression vane 120 according to the embodiment shown in FIGS. 5C to 5E.

[0054] Fig. 6 is a diagram showing another embodiment of the vortex suppression vane 120. In the above-described embodiment, the vortex suppression vane 120 has a lower end portion 120a that is inclined in an upwardly curved shape, but in the embodiment shown in Fig. 6, the lower end portion 120a of the vortex suppression vane 120 extends linearly in a direction perpendicular to the axis line CL.

[0055] 7A to 7E are diagrams showing other embodiments of the vortex suppression vane. In the embodiment shown in Fig. 7A, the vortex suppression vane 120 has a U-shaped notch 122A formed in the lower end portion 120a. In the embodiment shown in Fig. 7B, the vortex suppression vane 120 has the notch 122A and a plurality of holes H formed in the surface of the vortex suppression vane 120.

[0056] In the embodiment shown in Figure 7C, the vortex suppression vanes 120 have comb-shaped notches 122B. In the embodiment shown in Figure 7D, the vortex suppression vanes 120 have zigzag-shaped notches 122C. In the embodiment shown in Figure 7E, the vortex suppression vanes 120 have wave-shaped notches 122D.

[0057] These notches 122B, 122C, and 122D extend in a direction perpendicular to the axis CL (i.e., horizontally). By forming such notches 122A, 122B, 122C, and 122D, the vortex suppression structure AS can more actively disrupt the flow of water. Furthermore, by forming holes H on the surface of the vortex suppression vane 120, the flow of water can be more actively disrupted. The holes H may be formed in the vortex suppression vane 120 according to the embodiment shown in FIGS. 7C to 7E.

[0058] 8A to 8E are diagrams showing another embodiment of the vortex suppression vane, in which the vortex suppression vane 120 has notches 121A, 121B, 121C, and 121D and a hole H, similar to the vortex suppression vane 120 according to the embodiment shown in FIGS.

[0059] 9 is a diagram showing another embodiment of the boss portion of the vortex suppression structure. As shown in Fig. 9, the vortex suppression structure AS has a hollow boss portion 125 located at its center (i.e., the center of the suction bell mouth 15).

[0060] More specifically, the boss portion 125 has a through-hole 125a formed in its center. The through-hole 125a extends along the axis CL and allows water to flow in. Therefore, by arranging the hollow boss portion 125, the vortex suppression structure AS can disperse the inflow of water into the pump casing 10. As a result, the vortex suppression structure AS can more reliably suppress the generation of underwater vortices (see (A) above), and the operating stability of the pump P can be improved (see (C) above).

[0061] Fig. 10 is a diagram showing another embodiment of the vortex suppression structure. Fig. 11 is a diagram showing a curved long plate. As shown in Figs. 10 and 11, the vortex suppression structure AS includes a curved long plate 200 extending along the axis CL.

[0062] The curved long plate 200 is fixed to the pump casing 10 by a plurality of brackets BR. The curved long plate 200 is curved along the outer surface of the pump casing 10. The curved long plate 200 is a single plate extending along the direction of the axis CL.

[0063] Therefore, the debris in the suction tank ST flows smoothly without getting tangled in the curved elongated plate 200 (see (B) above). Furthermore, the curved elongated plate 200 can more actively disrupt the flow of water, and as a result, the pump P can improve its operational stability (see (A) and (C) above).

[0064] Fig. 12 is a diagram showing another embodiment of the vortex suppression structure. In the embodiment shown in Fig. 12, the vortex suppression structure AS includes a plurality of hollow rods 210 extending along the axis CL. In this embodiment, two hollow rods 210 are arranged, but the number of hollow rods 210 is not limited to this embodiment. In one embodiment, three or more hollow rods 210 may be arranged.

[0065] The hollow rods 210 have the same structure. Each hollow rod 210 has a through hole 210a extending along the axis CL, allowing the inflow of a fluid (e.g., water or compressed air). Each hollow rod 210 has a plurality of flow holes HL formed on its surface.

[0066] Therefore, by sending fluid into the hollow rod 210 through the through-hole 210a, the fluid is pushed out of the hollow rod 210 through the multiple flow holes HL. With this configuration, even if debris in the suction tank ST gets caught on the hollow rod 210, the debris can be removed from the hollow rod 210 by spraying fluid (see (B) above). Furthermore, the multiple hollow rods 210 can more actively disrupt the flow of water, and the pump P can improve its operational stability (see (A) and (C) above).

[0067] 13A and 13B illustrate another embodiment of a vortex suppression plate, in which at least one of the first vortex suppression plate 100 and the second vortex suppression plate 110 (see FIG. 1) has asperities CV formed on its surface SR.

[0068] The uneven CV is formed, for example, by embossing. By forming the uneven CV, the strength of the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) can be improved, and adhesion of dust to the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) can be prevented (see (B) above). Furthermore, the uneven CV can more actively disrupt the water flow, thereby improving the operational stability of the pump P (see (A) and (C) above).

[0069] In one embodiment, although not shown, the irregularities CV may be formed on the surface of the vortex suppression vane 120 according to the above-described embodiment (see FIGS. 4 to 9 ). With this configuration, the vortex suppression vane 120 can more reliably prevent dust from adhering to itself.

[0070] Fig. 14 is a diagram showing another embodiment of the vortex suppression structure. In the embodiment shown in Fig. 14, the vortex suppression structure AS includes a reinforcement member SF that entirely surrounds at least one of the first vortex suppression plate 100 and the second vortex suppression plate 110. The reinforcement member SF is formed by, for example, an FRP lining that uses fiber-reinforced plastic.

[0071] The reinforcing material SF can improve the strength of the first vortex suppression plate 100 (and / or the second vortex suppression plate 110). Therefore, the vortex suppression structure AS can prevent wear of the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) caused by fine debris (e.g., sand) in the suction sump ST (see (B) above). Furthermore, by preventing such wear, the operational stability of the pump P can be improved (see (C) above).

[0072] Fig. 15 is a diagram showing another embodiment of the vortex suppression structure. In the embodiment shown in Fig. 15, the main shaft 1 extends to below the suction bell mouth 15 (more specifically, the vortex suppression vanes 120 fixed to the lower part of the suction bell mouth 15). The vortex suppression structure AS has a revolving boss portion 250 fixed to the tip end 1a of the main shaft 1.

[0073] The swivel boss portion 250 is configured to rotate together with the rotation of the main shaft 1. The swivel boss portion 250 has a swivel groove 250a extending in the direction of the axis line CL. When the swivel boss portion 250 rotates, the swivel groove 250a rotates around the swivel boss portion 250.

[0074] Therefore, even if debris gets caught in the swivel boss 250, the debris is cut off or removed from the swivel boss 250 by the rotation of the swivel groove 250a. As a result, the vortex suppression structure AS can prevent debris from adhering to the swivel boss 250 (see (B) above). Furthermore, by preventing such debris from adhering, the operational stability of the pump P can be improved (see (C) above).

[0075] Fig. 16 is a diagram showing a vortex suppression structure including an imaging device. In the embodiment shown in Fig. 16, the vortex suppression structure (i.e., vortex suppression device) AS includes an imaging device CA that captures images of a plurality of hollow rods 210 (see Fig. 12), and a control device CR configured to determine whether or not a foreign object is attached to each of the plurality of hollow rods 210 based on the imaging data captured by the imaging device CA.

[0076] The imaging device CA is fixed to the top of the hollow rod 210 and is configured to be able to capture an image of the entire hollow rod 210. The control device CR is electrically connected to the imaging device CA and is configured to periodically acquire imaging data.

[0077] Therefore, if dust is attached to the hollow rod 210, the image capturing device CA captures an image of the dust attached to the hollow rod 210, and the control device CR determines that dust is attached to the hollow rod 210. The worker can remove the dust as appropriate based on the determination result by the control device CR.

[0078] In this embodiment, the imaging device CA is configured to capture an image of the hollow rod 210, but the imaging device CA may also be configured to capture an image of components of the vortex suppression structure AS (e.g., vortex suppression plates 100, 110, vortex suppression vanes 120, curved elongated plate 200, etc.).

[0079] Fig. 17A is a diagram showing the number of blades of the impeller, and Fig. 17B is a diagram showing the number of vortex suppression vanes. The impeller 2 has three blades 2a (see Fig. 17A), while the vortex suppression structure AS has four vortex suppression vanes 120 (see Fig. 17B).

[0080] In this way, the number of vortex suppression vanes 120 is different from the number of blades 2a. This configuration can prevent pulsation (i.e., periodic fluctuations) in the flow (flow rate) of water when water is sucked into the pump P. As a result, the pump P can prevent vibration during operation, improving the operational stability of the pump P (see (C) above).

[0081] 17C and 17D are views showing a flange portion to which the vortex suppression vanes are fixed. In this embodiment, the vortex suppression structure AS includes a flange portion FP to which a plurality of vortex suppression vanes 120 are fixed. The flange portion FP is removably attached to the suction bell mouth 15 by bolts BT (see FIG. 17C ).

[0082] More specifically, the flange portion FP has an annular shape (see FIG. 17D) and has bolt holes BH into which bolts BT can be inserted. The bolt holes BH are formed around the entire circumference of the flange portion FP.

[0083] For ease of transportation, when the pump casing 10 and the vortex suppression vanes 120 are transported separately to a site (e.g., a foreign country), it is necessary to connect the vortex suppression vanes 120 to the pump casing 10 at the site.

[0084] In this embodiment, the multiple vortex suppression vanes 120 and the flange portion FP are integrally configured. Therefore, an operator can fix the multiple vortex suppression vanes 120 to the lower part of the suction bell mouth 15 by the simple method of simply connecting the flange portion FP to the suction bell mouth 15 with bolts BT. Furthermore, by forming bolt holes BH around the entire circumference of the flange portion FP, the pump P can be installed in the suction sump ST without considering the orientation of the pump P in the rotational direction of the impeller 2.

[0085] 18 is a diagram illustrating another embodiment of a vortex suppression plate, in which at least one of the first vortex suppression plate 100 and the second vortex suppression plate 110 has through holes TH formed in its surface SR.

[0086] By forming such through holes TH, water flowing through the suction sump ST passes through the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) through the through holes TH, thereby reducing the impact of water contacting the first vortex suppression plate 100 (and / or the second vortex suppression plate 110).

[0087] In this embodiment, it is possible to improve the durability of the first vortex suppression plate 100 (and / or the second vortex suppression plate 110). As a result, the vortex suppression structure AS can more reliably suppress the generation of underwater vortices (see (A) above), and the operational stability of the pump P can be improved (see (C) above).

[0088] 19A and 19B show another embodiment of the vortex suppression plate. In the embodiment shown in Figures 19A and 19B, at least one of the first vortex suppression plate 100 and the second vortex suppression plate 110 has a plurality of ribs RB1, RB2 formed on its surface SR. Each of the plurality of ribs RB1, RB2 has a convex shape.

[0089] In the embodiment shown in Fig. 19A, the ribs RB1 are vertical ribs extending along the axis CL, whereas in the embodiment shown in Fig. 19B, the ribs RB2 are horizontal ribs extending in a direction perpendicular to the axis CL.

[0090] In this embodiment, by forming multiple ribs RB1, RB2, the strength of the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) can be improved. Therefore, the vortex suppression structure AS can more reliably suppress the generation of underwater vortices (see (A) above) and prevent debris from sticking to the first vortex suppression plate 100 (and / or the second vortex suppression plate 110) (see (B) above). As a result, the operational stability of the pump P can be improved (see (C) above).

[0091] 20 is a diagram showing another embodiment of the vortex suppression structure. The vortex suppression structure AS includes a suction-side water level gauge 300A that detects the water level in the suction tank ST, a discharge-side water level gauge 300B that detects the water level in the discharge tank DT, and a control device CR electrically connected to the suction-side water level gauge 300A and the discharge-side water level gauge 300B. The discharge tank DT is a water tank for storing water pumped by a pump P and is connected to the pump P through a discharge pipe DP.

[0092] The control device CR is configured to control the operation of the pump P (more specifically, the flow rate of water sucked into the pump P) based on water level data detected by the suction-side water level gauge 300A and the discharge-side water level gauge 300B. Here, the water level data is data that includes the water level difference between the water level detected by the suction-side water level gauge 300A and the water level detected by the discharge-side water level gauge 300B.

[0093] The control device CR calculates the pump flow rate (i.e., the flow rate of water sucked into the pump P) based on the water level data. The control device CR calculates the approach flow rate of water to the pump P based on the pump flow rate and the water level in the suction tank ST, and if the calculated value is greater than a predetermined threshold, operates the pump P to reduce the flow rate of water being pumped.

[0094] With this configuration, the vortex suppression structure AS can more reliably suppress the occurrence of underwater vortices (see (A) above), and the pump P can improve the stability of pump operation without being affected by underwater vortices (see (C) above).

[0095] In this embodiment, the control device CR is configured to calculate the water level of the discharge tank DT based on the water level detected by the discharge side water level meter 300B, but in one embodiment, the control device CR may also calculate the water level of the discharge tank DT based on the pressure detected by a pressure meter PR (see Figure 20) arranged on the discharge side of the pump P.

[0096] In one embodiment, the control device CR measures the water level of the suction tank ST based on the water level data detected by the suction-side water level meter 300A, and determines whether the measured water level has dropped to a predetermined level. When the measured water level has dropped to the predetermined level, the control device CR is configured to reduce the flow rate of water pumped by the pump P.

[0097] The control device CR may control the water flow rate by changing the angle of the blades 2a of the impeller 2, by changing the rotational speed of the impeller 2, or by controlling the opening of the discharge valve DV attached to the discharge pipe DP connected to the discharge elbow 12 of the pump P.

[0098] Fig. 21 is a diagram showing another embodiment of the vortex suppression structure AS. In the embodiment shown in Fig. 21, the vortex suppression structure AS includes a vibration meter 400 attached to the pump casing 10 and a control device CR electrically connected to the vibration meter 400.

[0099] The control device CR is configured to measure the vibration value of the pump P (more specifically, the pump casing 10) based on the vibration data detected by the vibration meter 400, and to reduce the flow rate of water pumped by the pump P when the measured vibration value increases to a predetermined threshold value. With this configuration, the control device CR can suppress the vibration of the pump P. Therefore, the operation stability of the pump P can be improved.

[0100] The above-described embodiments can be combined as appropriate. More specifically, the vortex suppression structures AS described with reference to Figures 1 to 21 may be combined as much as possible to achieve at least one of the above (A) to (C).

[0101] The above-described embodiments have been described for the purpose of enabling a person of ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments would be obvious to a person skilled in the art, and the technical concept of the present invention may be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope in accordance with the technical concept defined by the claims.

[0102] The present invention can be used in pumps.

[0103] DESCRIPTION OF SYMBOLS 1 Main shaft 1a Tip 2 Impeller 2a Blade 10 Pump casing 11 Lifting pipe 12 Discharge bend 15 Suction bell mouth 15a Suction port 16 Impeller casing 17 Discharge bowl 20 Pump installation floor 20a Opening 21 Hanging pipe 100 First vortex suppression plate 100a Lower end 110 Second vortex suppression plate 110a Lower end 111A, 111B, 111C Notch 120 Vortex suppression vane 120a Lower end 120b Side end 121A, 121B, 121C, 121D Notch 122A, 122B, 122C, 122D Notch 200 Curved long plate 210 Hollow rod 210a Through hole 250 Swivel boss portion 250a Swivel groove 300A Suction side water level gauge 300B Discharge side water level gauge 400 Vibration meter P Pump ST Suction water tank AS Vortex suppression structure CL Axis BR Bracket H Hole HL Flow hole CV Irregularities SR Surface SF Reinforcement material CA Imaging device CR Control device FP Flange portion BT Bolt BH Bolt hole TH Through hole RB1 Vertical rib RB2 Horizontal rib DT Discharge water tank DV Discharge valve PR Pressure gauge

Claims

1. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises a first vortex suppression plate and a second vortex suppression plate arranged along the axial direction of the main shaft.

2. The pump of claim 1, wherein at least one of said first vortex suppression plate and said second vortex suppression plate has a notch formed in a lower end thereof.

3. The pump according to claim 1, wherein at least one of the first vortex suppression plate and the second vortex suppression plate has irregularities formed on its surface.

4. The pump of claim 1, wherein the vortex suppression structure comprises a stiffener that entirely surrounds at least one of the first vortex suppression plate and the second vortex suppression plate.

5. The pump according to claim 1, wherein at least one of said first vortex suppression plate and said second vortex suppression plate has through holes formed in a surface thereof.

6. The pump of claim 1, wherein at least one of said first vortex suppression plate and said second vortex suppression plate has a plurality of ribs formed on a surface thereof.

7. The pump of claim 1, wherein at least one of the first vortex suppression plate and the second vortex suppression plate has a shrimp-like shape.

8. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises vortex suppression vanes fixed to a lower part of a suction bell mouth of the pump casing, and the vortex suppression vanes are inclined in a curved manner upward toward the center of the suction bell mouth.

9. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises vortex suppression vanes fixed to a lower part of a suction bell mouth of the pump casing, and the vortex suppression vanes have notches formed on their side ends.

10. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure has a hollow boss portion arranged in the center.

11. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the main shaft extends to below the suction bell mouth of the pump casing, and the vortex suppression structure has a swivel boss portion fixed to the tip of the main shaft.

12. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises a curved, long plate extending along the axial direction of the main shaft.

13. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises a plurality of hollow rods extending along the axial direction of the main shaft, and each of the plurality of hollow rods has a plurality of flow holes.

14. The pump described in claim 13, wherein the vortex suppression structure comprises: an imaging device that images the plurality of hollow rods; and a control device that determines whether or not foreign matter is attached to each of the plurality of hollow rods based on the imaging data captured by the imaging device.

15. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises vortex suppression vanes arranged below the suction bell mouth of the pump casing, and the vortex suppression vanes have a number different from the number of blades on the impeller.

16. The pump according to claim 15, wherein the vortex suppression structure comprises a flange portion to which the vortex suppression vanes are fixed, and the flange portion is removably attached to the suction bell mouth.

17. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure is equipped with a control device that reduces the flow rate of water pumped by the pump based on water level data detected by a suction-side water level gauge that detects the water level in the suction tank and a discharge-side water level gauge that detects the water level in the discharge tank.

18. A pump for pumping water from a suction tank, comprising: a main shaft; an impeller fixed to the main shaft; a pump casing that houses the impeller; and a vortex suppression structure arranged on the outside of the pump casing, wherein the vortex suppression structure comprises: a vibrometer attached to the pump casing; and a control device electrically connected to the vibrometer, wherein the control device measures the vibration value of the pump casing based on vibration data detected by the vibrometer, and reduces the flow rate of water pumped by the pump when the measured vibration value increases to a predetermined threshold value.

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