JP2004044138A - Pump gate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower the lowest operatable water level of a pump. <P>SOLUTION: A gate door 3 is installed openably/closably in the middle position of a waterway 2 reaching a river stream 1. An intake passage 9a communicating with a suction opening 10 of the upstream side face of the gate door 3 and delivery opening 11 of the downstream side face are formed. A horizontal pump 4 is connected to the delivery opening to constitute a pump gate. The opening 10 is formed in a rectangular shape to give a ceiling extending in the right and left horizontal direction in a low position near to the axial center of the pump 4. The corners 19 at the right and left ends of the ceiling are rounded and the sharp corners are eliminated. The ceiling face 18 of the passage 9a is constituted of a ceiling face 18c rising while smoothly curving from the ceiling face 18a of the opening 10 to the ceiling face 18b of the opening 11. The upstream side end of the face 18a is formed horizontally or somewhat downward of the horizon and connected to the opening 10. When the operatable water level is reached after closure of the waterway by the door 3, the pump 4 is operated to forcibly drain from the waterway 2 to the river. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is installed in the middle of a waterway (including a small river) leading to the main river (a relatively large river), and when the outside water level on the downstream side of the waterway rises and the gate is closed, the waterway from the upstream of the waterway is The present invention relates to a pump gate in which a pump for forcibly draining water downstream is integrally attached to a gate.
[0002]
[Prior art]
Waterways (including small rivers), such as rainwater drains and agricultural waterways, that lead to relatively large rivers that become the main river, usually regulate the amount of water flowing from upstream to downstream, and Drainage gates are provided to control the amount of drainage.However, when the inflow of water into the main river and waterway increases temporarily and the water level rises rapidly, such as during a typhoon or heavy rain, Even if the gate is fully opened, not only the water in the waterway (inland water) cannot be drained sufficiently, but also when the water of the main river (outside water) flows back to the waterway, the water overflows from the waterway and the surrounding area is flooded. A disaster will occur. Therefore, as one way to prevent such disasters, water can be forcibly drained from the upstream of the water channel to the downstream of the water channel, and even if the water level of the main river rises, the backflow of water from the main river to the water channel can be prevented. There is a case where a pump gate as the drainage facility is installed in the middle of the waterway.
[0003]
Conventionally, as one of such pump gates, there is a river table type as schematically shown in FIG. This means that a gate door body 3 such as a roller gate door body is arranged to be able to ascend and descend at a required point in the middle of a waterway 2 leading to the main river 1, for example, near a junction with the main river 1 as shown in FIG. Further, a horizontal shaft pump 4 is integrally attached to the downstream side surface of the gate door body 3 in the water channel downstream direction to form a pump gate 5, and the pump gate 5 is operated by operating a gate elevator 7 installed on an upper operation table 6. When the water level (outside water level) of the main river 1 is lower than the water level (inner water level) of the water channel 2, the gate door 3 of the pump gate 5 is indicated by a two-dot chain line in FIG. By pulling up and opening the waterway 2 as shown, the water in the waterway 2 is drained by natural flow to the main river 1 side. On the other hand, when the external water level is higher than the internal water level, to prevent backflow, As shown by the solid line in FIG. 5 is lowered to close the water channel 2 with the gate door body 3 so as to prepare for the pump operation. When the internal water level rises and reaches the pump operable water level, the horizontal axis pump 4 is operated, thereby discharging the internal water. It is forcibly discharged to the Honkawa side. Reference numeral 8 denotes a power supply cable for the horizontal shaft pump 4.
[0004]
The specific configuration of the gate door 3 and the horizontal pump 4 constituting the horizontal axis pump gate is shown in FIG. 7A and FIG. At one or two lower required positions, a suction port 10 is opened at the upstream side of the water channel 2, and a suction channel 9 for a pump is penetrated so as to open an air outlet 11 at the downstream side of the water channel 2. The suction flow path 9 has an inner diameter corresponding to the diameter of the pump over the entire length, and is formed substantially horizontally in the upstream and downstream directions of the water channel 2. On the other hand, the horizontal shaft pump 4 is provided with a submersible motor 13 at an axial center position in a horizontal pump casing 12 having one end serving as a suction port 12a and the other end serving as a discharge port 12b. While being fixed to the inner surface of the pump casing 12, an axial pump blade 15 is integrally connected to an output shaft (not shown) of the underwater motor 13, and a pump operation is stopped at a discharge port 12b of the pump casing 12. As a configuration including a flap valve 16 for preventing backflow at the time, the suction port 12a side of the pump casing 12 is attached to the periphery of the outlet 11 of the suction passage 9 of the gate door body 3, It is designed to communicate with the outlet 11.
[0005]
By the way, in general, if the operable suction water level of the pump gate 5 can be set low, the number of times of starting and stopping the pump can be reduced, so that the lowest operable water level on the suction side is lowered in the market. It is desired.
[0006]
[Problems to be solved by the invention]
However, at the time of low water level operation, the suction side water surface W.W. L. When the air suction vortex 17 is generated and the horizontal axis pump 4 easily sucks air, and the air is sucked into the horizontal axis pump 4 in this way, vibration occurs in the horizontal axis pump 4, There is a problem that damage may occur. As a countermeasure, it is conceivable to attach a component such as a suction throat for preventing the generation of an air suction vortex on the suction side. If a component such as a suction throat for preventing the generation of the air suction vortex is attached to the gate door 3, the component protrudes from the upstream side surface of the gate door body 3 and hinders the opening and closing of the gate.
[0007]
Therefore, at present, it has been practiced to reduce the flow rate by lowering the rotation speed of the horizontal shaft pump 4 so as to prevent air suction from the water surface. However, there is a problem that the manufacturing cost increases because the rotation speed controller is required.
[0008]
Further, since the suction passage 9 of the conventional gate door body 3 is formed so as to have an inner diameter corresponding to the pump diameter over the entire length, the suction port 10 also has a circular shape. Is circular, there is a problem that the water flow flowing from the water surface side (above) tends to concentrate on the upper end portion of the suction port 10 and that the air is easily swirled, so that the air suction vortex 17 is easily formed.
[0009]
Therefore, the present invention can set the minimum water level at which the pump can be operated low without attaching any parts to the upstream side surface of the gate door body, and can further suppress the occurrence of air suction vortex, and operate at low water level operation. It is another object of the present invention to provide a pump gate capable of suppressing the occurrence of air suction from the water surface.
[0010]
[Means for Solving the Problems]
The present invention, in order to solve the above-mentioned problem, communicates a suction port opened on the upstream side of the channel and an outlet opened on the downstream side of the channel at a required position of the gate door that opens and closes the channel. A suction passage for the pump is provided, and the suction side of the pump is attached to the outlet of the suction passage so that the suction side of the pump coincides with the suction passage. In the pump gate configured to be capable of forcibly draining water, the ceiling surface of the suction channel on the suction port side is formed to be lower than the ceiling surface on the air outlet side, and further, the suction channel The ceiling surface on the suction port side and the ceiling surface on the air outlet side are continuous with a flat ceiling surface.
[0011]
When forcibly draining water from a channel to a river, the pump is driven with the channel closed by the gate door. At this time, the suction opening of the suction flow passage has a ceiling surface set low and is separated from the water surface, so that operation is possible even if the water level in the water channel is lower than in the past.
[0012]
Also, the ceiling surface of the suction flow path is smoothly curved and rises from the suction port side to the air outlet side, so that the ceiling surface on the air inlet side and the ceiling surface on the air outlet side have a large height. Even if there is a difference, the direction of the water flow flowing through the suction flow path does not suddenly change, and therefore, the water flow separates from the ceiling surface, the flow path resistance increases, and the suction resistance of the pump may increase. It can be prevented before it happens.
[0013]
Furthermore, the upstream end of the ceiling surface on the suction port side of the suction flow path is configured so as to be horizontal or slightly lower than horizontal, so that the upstream side of the gate door body faces downward on the suction side water surface near the suction side. The flow can be weakened, and even when the suction-side water surface is wavy, the risk of sucking air from the water surface can be prevented.
[0014]
Further, the suction port of the suction channel is formed in a rectangular shape that extends horizontally so that the ceiling surface is parallel to the water surface, so that the water flow flowing from the water surface side is concentrated at one location on the ceiling surface of the suction port. It is possible to prevent the occurrence of swirling of the flow and to suppress the occurrence of the air suction vortex more effectively.
[0015]
Furthermore, the ceiling at the left and right ends of the ceiling of the suction port is formed in a circular arc shape having no corners or a configuration in which the corners are bent stepwise so as to widen the angle of the corner, so that the ceiling of the suction port Can be prevented from occurring at the corners, and the occurrence of the air suction phenomenon at the corners can be suppressed.
[0016]
Furthermore, since the suction port of the suction channel is formed to have a wide left and right width, the area of the suction port of the suction channel can be increased, so that the unit area of the water flow passing through the suction port portion can be increased. The flow velocity per contact can be reduced, and the generation of the air suction vortex can be further suppressed.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 shows an embodiment of a pump gate according to the present invention. Like the river table type pump gate 5 shown in FIGS. 6 and 7 (a) and (b), a water channel 2 connected to the main river 1 is shown. A gate passage 3 is provided at a required position in the middle of the passage so as to be able to move up and down by a gate elevator 7, and the gate passage 3 communicates a suction port 10 on the upstream side of the waterway and an outlet 11 on the downstream side of the waterway. 6 and 7 (a) and (b) in a pump gate having a configuration in which the pump casing 12 is mounted so that the suction port 12a side of the horizontal axis pump 4 is aligned with the outlet 11 of the suction flow path 9. ), Instead of a configuration in which the ceiling surface of the suction passage 9 from the suction port 10 to the outlet 11 is formed in a horizontal state, such as the suction passage 9 formed in the gate door body 3 shown in FIG. The ceiling surface 18 is smoothly curved and blown from the suction port 10 side. A shape such that upwards to the mouth 11 side. That is, the position of the ceiling surface 18 a of the suction port 10 is lowered to a position lower than the position of the ceiling surface 18 b of the outlet 11, for example, to the vicinity of the axis of the horizontal shaft pump 4 attached to the outlet 11. The suction surface formed so that the ceiling surface 18c between the ceiling surface 18a of the suction port 10 and the ceiling surface 18b of the outlet 11 is smoothly curved and rises. Let it be a flow path 9a.
[0019]
The end of the ceiling surface 18a on the suction port 10 side of the ceiling surface 18 of the suction flow path 9a is connected to the suction port 10 at a horizontal angle or a slightly lower angle than the horizontal toward the upstream side.
[0020]
Further, the suction port 10 of the suction channel 9a has a square shape with at least an upper half extending horizontally in the left-right width direction so that the ceiling surface 18a is parallel to the water surface. Is made rectangular in cross section. The corners 19 at both left and right ends of the ceiling surface 18a of the rectangular suction port 10 are rounded by dropping corners.
[0021]
Further, the rectangular suction port 10 is formed to be wide in the left-right direction so that the flow rate of the water flowing through the suction port 10 per unit area can be reduced.
[0022]
In addition, the same components as those shown in FIGS. 7A and 7B are denoted by the same reference numerals.
[0023]
When the pump gate of the present invention is used, similarly to the conventional pump gate 5, when the external water level is lower than the internal water level, the gate door 3 is pulled up by the gate elevator 7 to open the water passage 2. Thereby, the water in the water channel 2 is drained to the main river side by natural flow.
[0024]
On the other hand, when the outside water level becomes higher than the inside water level, as shown by a solid line in FIG. 1, the gate door body 3 is lowered by the opening / closing device, and the water passage 2 is closed to prepare for the pump operation. When the pump operation water level is reached, the horizontal water pump 4 is operated, so that the internal water is guided to the horizontal water pump 4 through the suction passage 9a and then is forcibly discharged to the downstream side on the main river side. Become like At this time, since the position of the ceiling surface 18a of the suction port 10 of the suction flow passage 9a is formed at a low position near the axial center position of the horizontal shaft pump 4, the horizontal shaft pump 4 is 7 (a) and (b), it is possible to operate at a lower water level than when connected to the conventional suction passage 9 as shown in FIG. 7 (b). The lowest operable water level can be set low. Further, since the ceiling surface 18 of the suction passage 9a is continuously formed by a smoothly curved ceiling surface 18c from the ceiling surface 18a of the suction port 10 to the ceiling surface 18b of the air outlet 11, the ceiling surface of the suction port 10 is formed. Even if the height difference between the ceiling 18a and the ceiling surface 18b of the outlet 11 is large, the direction of the water flow flowing through the suction flow passage 9a does not suddenly change. It is possible to prevent the resistance from increasing.
[0025]
Further, since the upstream end of the ceiling surface 18a of the suction port 10 in the ceiling surface 18 of the suction flow path 9a is connected to the suction port 10 at a horizontal angle or at a slightly lower angle than the horizontal, the suction port 10 The downward flow of the inflowing water flow can be weakened. For example, as shown in FIG. 2, the upstream end of the ceiling surface 18a of the suction port 10 of the suction flow path 9a is connected to the suction port 10 at an upward angle. When formed, the downward flow velocity of the water flowing into the suction port 10 becomes large, and when the suction-side water surface on the upstream side of the gate door body 3 undulates when forced drainage is performed by the pump 4, the wave With the driving, there is a possibility that air is sucked along the upstream end of the ceiling surface 18a of the suction port 10 as shown by an arrow l in FIG. In this regard, in the pump gate of the present invention, even when the water surface on the upstream side of the gate door body 3 is wavy, it is possible to prevent the possibility of inhaling air beforehand.
[0026]
On the other hand, as shown in FIG. 3, when the upstream end of the ceiling surface 18a of the suction port 10 of the suction channel 9a is connected to the suction port 10 at a steep downward angle, the position of the suction port 10 is determined. At this time, since a sudden change of direction occurs in the water flow flowing from above, there is a possibility that the water flow separates from the ceiling surface 18a of the suction port 10 as shown by the arrow m in FIG. However, since the upstream end of the ceiling surface 18a of the suction port 10 of the suction flow passage 9a in the pump gate of the present invention is connected to the suction port 10 at a horizontal angle or at a slightly lower angle than the horizontal, the water flow Can flow along the ceiling surface 18a from the ceiling surface 18c to 18c and 18b, and can be separated from the ceiling surface 18.
[0027]
Further, when the suction port 10 of the suction flow path 9a is formed so that the ceiling portion has a rectangular shape extending horizontally in the left-right direction, the suction port 10 is formed like the suction flow path 9 of the conventional pump gate 5. The swirling of the flow can be reduced as compared with the case of the circular shape, and the flow from above does not concentrate on a part, so that the generation of the air suction vortex can be further suppressed. As shown in FIG. 4, when the corners 19 at the left and right end portions of the ceiling surface 18 of the rectangular suction port 10 are not dropped and are formed at right angles, the corner 19 A pressure drop may occur, and air may be sucked from the water surface toward the corner 19 as shown by an arrow n in FIG. 4, but the suction port of the suction flow passage 9a in the pump gate of the present invention. When the corners 19 at both ends of the ceiling surface 18 are rounded with rounded corners as in 10, the occurrence of a pressure drop phenomenon at the corners 19 can be suppressed, and air is sucked from the water surface. Can be suppressed.
[0028]
Further, if the rectangular suction port 10 is formed to be wide and the area of the suction port 10 is enlarged, the flow velocity of the water flow flowing through the suction port 10 can be reduced, whereby the air Can be more reliably prevented from being transported to the horizontal pump 4 with the water flow.
[0029]
Note that the present invention is not limited to the above embodiment, and the horizontal shaft pump 4 is of a type in which a pump blade 15 is driven by a submersible electric motor 13 disposed at an axial position of a pump casing 12. However, only the pump 15 blades may be rotatably supported at the center of the pump casing 12, and the pump blades 15 may be driven by a submersible electric motor or an electric motor provided outside the pump casing 12. That is, if the suction port 10 of the suction channel 9a provided in the gate door body 3 has an upper half formed in a square shape having a ceiling extending horizontally in the left-right direction, the lower half has a semicircular shape. In FIG. 1, the ceiling surface 18 of the suction passage 9 a is formed by connecting the ceiling surface 18 a of the suction port 10 and the ceiling surface 18 b of the air outlet 11 to each other. Between, smoothly curved Although the shape is shown as being continuous by the rising ceiling surface 18c, when the height difference between the ceiling surface 18a of the suction port 10 and the ceiling surface 18b of the outlet 11 is small, the shape is made to be continuous by the flat ceiling surface. Although the corners 19 at the left and right ends of the ceiling surface 18a of the suction port 10 may be rounded by dropping corners, the corners 19 may be bent stepwise as shown in FIG. Needless to say, the shape of the corner may be widened, and various changes may be made without departing from the scope of the present invention.
[0030]
【The invention's effect】
As described above, according to the pump gate of the present invention, the following excellent effects are exhibited.
(1) At a required position of a gate door body that opens and closes a water channel, a suction channel for a pump is provided that communicates a suction port opened on an upstream side surface of the water channel with an air outlet opened on a downstream side surface of the water channel of the gate door body, A pump in which the suction side of the pump is fitted to the outlet of the suction passage so that the suction side of the pump coincides with the outlet, and the pump is driven by closing the water channel by the gate door so that the water can be forcibly drained from the upstream side to the downstream side. In the gate, the ceiling surface on the suction port side of the suction channel is formed so as to be lower than the ceiling surface on the air outlet side. Since the ceiling surface on the outlet side is configured to be continuous with the flat ceiling surface, the lowest operable water level of the pump can be set low.
(2) By making the ceiling surface on the suction port side and the ceiling surface on the air outlet side of the suction channel continuous with a smoothly curved curved ceiling surface, the ceiling surface on the suction port side and the air outlet side Even if there is a large height difference on the ceiling surface, the direction of the water flow flowing through the suction flow path does not suddenly change, so that the water flow separates from the ceiling surface and the flow path resistance increases, and the suction resistance of the pump increases. Can be prevented from increasing.
(3) The upstream end of the ceiling surface on the suction port side of the suction flow path is horizontal or slightly lower than horizontal, so that it faces downward near the suction-side water surface on the upstream side of the gate door body. The flow can be weakened, and even when the suction-side water surface is wavy, the risk of sucking air from the water surface can be suppressed.
(4) The suction port of the suction channel is formed in a rectangular shape that extends horizontally so that the ceiling surface is parallel to the water surface, so that the water flow flowing from the water surface side is concentrated at one location on the ceiling surface of the suction port. It is possible to prevent the occurrence of swirling of the flow and to suppress the occurrence of the air suction vortex more effectively.
(5) The ceiling of the suction port is formed by forming the corners at both left and right ends of the ceiling of the suction port into a circular arc shape having no corners or a shape in which the corners are bent stepwise to increase the angle of the corners. Can be prevented from occurring at the corners, and the occurrence of the air suction phenomenon at the corners can be suppressed.
(6) Since the suction port of the suction channel is formed to be wide left and right, the area of the suction port of the suction channel can be increased, and thus the unit area of the water flow passing through the suction port portion. The flow velocity per hit can be reduced, and the generation of the air suction vortex can be further suppressed.
[Brief description of the drawings]
FIG. 1 shows an embodiment of a pump gate according to the present invention, wherein (a) is a schematic cut-away side view, and (b) is a schematic front view.
FIG. 2 is a diagram showing, as a comparison with the pump gate of FIG. 1, an air suction phenomenon occurring when the upstream end of the ceiling surface of the suction flow path is directed upward and connected to the suction port.
FIG. 3 shows, as a comparison with the pump gate shown in FIG. 1, a phenomenon in which a water flow separates from the ceiling surface when the upstream end of the ceiling surface of the suction flow path is connected to the suction port with a steep downward angle. FIG.
FIG. 4 is a diagram showing, as a comparison with the pump gate of FIG. 1, an air suction phenomenon from the water surface that occurs when a corner of a ceiling portion of a square-shaped suction port has a corner.
FIG. 5 is a schematic front view showing another shape of the corners at the left and right ends of the ceiling of the suction port in the present invention.
FIG. 6 is a cut-away side view schematically showing an example of a conventionally used pump gate.
7 is an enlarged view of the pump gate of FIG. 6, wherein (a) is a cut side view and (b) is a front view.
[Explanation of symbols]
2 Waterway 3 Gate door 4 Horizontal axis pump (pump)
9, 9a Suction channel 10 Suction port 11 Outlet port 18, 18a, 18b, 18c Ceiling surface 19 Corner

Claims (7)

At a required position of the gate door body that opens and closes the water passage, a suction passage for a pump is provided, which communicates a suction port opened on the upstream side surface of the water passage with an air outlet opened on the downstream side surface of the water passage of the gate door body. In the pump gate, the suction side of the pump is attached to the outlet of the road so that the suction side is aligned, and the drainage can be forcibly drained from the upstream side to the downstream side by closing the water channel by the gate door body and driving the pump. A pump gate having a configuration in which a ceiling surface on the suction port side of the suction flow path is formed to be lower than a ceiling surface on the air outlet side. 2. The pump gate according to claim 1, wherein a ceiling surface on the suction port side and a ceiling surface on the air outlet side of the suction flow path are continuous with a flat ceiling surface. 2. The pump gate according to claim 1, wherein the ceiling surface on the suction port side and the ceiling surface on the air outlet side of the suction flow path are continuous with a smoothly curved curved ceiling surface. 4. The pump gate according to claim 1, wherein the upstream end of the ceiling surface on the suction port side of the suction passage is horizontal or slightly downward from horizontal. 5. The pump gate according to claim 1, wherein the suction port of the suction channel has a rectangular shape extending horizontally so that a ceiling surface is parallel to a water surface. 6. The pump gate according to claim 5, wherein the corners at the left and right ends of the ceiling of the suction port are formed in a circular arc shape having no corners or in a shape in which the corners are gradually bent to increase the angle of the corners. The pump gate according to claim 1, 2, 3, 4, 5, or 6, wherein a suction port of the suction flow path is formed to be wide left and right.

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