River gate pump with screen

Abstract

To provide a river gate pump with screen which does not require an installation of a separate dust removal facility, takes into consideration measures against clogging of a screen due to dust during pump operation, and can cope with continuous pump operation for as long a period as possible.SOLUTION: If rack rods 65A, 65B are driven vertically in sync for a predetermined time, movable screens 6A, 6B will repeatedly rise and fall opposite fixed screens 5A, 5B, as shown in Figures 7(a) to 7(c). Scrapers 68A, 68B are attached to upper ends of the movable screens 6A, 6B on a gate 2. Therefore, as shown in Figure 7(b), when the movable screens 6A, 6B rise opposite the fixed screens 5A, 5B, the scrapers 68A, 68B scrape off the debris captured by the movable screens 6A, 6B.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a river-side gate pump equipped with a screen that prevents clogging of the screen due to debris during pump operation. More specifically, the present invention relates to a river-side gate pump that is equipped with both a fixed screen and a movable screen, in a gate pump that integrates a water gate and a pump. [Background technology]

[0002] In river-front installations of Gate Pumps (registered trademark), which integrate a sluice gate and a pump, the dust removal equipment used to remove inflowing debris typically consists of a lift-up dust remover or screen located near the entrance to the culvert on the backside of the river. However, in urban areas, the lack of available land for dust removal equipment on the backside of the river, the lack of an open channel section, and the fact that the upstream section of the culvert continues as a culvert make installation of dust removal equipment difficult. To address this issue, a simple screen may be installed underground within the culvert, but many local governments struggle with how to remove and transport the debris when it becomes clogged. In response to this, a two-stage, front-to-rear screen guide automatic switching system for dust removal has been proposed for industrial and agricultural waterways, etc., featuring a double screen guide with a front and rear net screen. This system has been designed to remove debris from these waterways. (Patent Document 1)

[0003] Similarly, a system has been proposed in which a second screen is movably (movably) installed above the first screen, and when removing the debris captured by the second screen, the second screen is pulled up from the waterway and the debris is removed with an adsorption film (Patent Document 2). Also proposed is a pump gate equipped with a screen that captures debris flowing through the waterway before it is sucked into the pump (Patent Document 3). The applicant of the present invention also proposed a gate pump facility with a water control door that allows both the gate body and the water control door for preventing backflow to be raised and lowered with a single gate operator (Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 53-011141 [Patent Document 2] Japanese Patent Publication No. 2022-94004 [Patent Document 3] Japanese Patent Application Laid-Open No. 2002-275871 [Patent Document 4] Japanese Patent Application Laid-Open No. 2002-327426 Summary of the Invention [Problem to be solved by the invention]

[0005] The two-stage, front-to-rear screen guide automatic switching net screen for dust removal described in Patent Document 1 above has the following configuration: while the front net screen is being used to remove dust with a spray nozzle at the top, the rear net screen captures dust at the bottom; while the rear net screen is being used to remove dust with a spray nozzle at the top, the front net screen moves down to capture dust. In other words, the screen is raised, and dust removal is performed with the spray nozzle. Furthermore, if a pump with excellent debris permeability is used, lifting up the dust is not necessarily necessary in rivers with a lot of natural dust, such as aquatic plants. Even if lifting up the dust would increase the cost of dust disposal. Similarly, the screen dust removal equipment described in Patent Document 2 lifts up the second screen into the waterway, and while the dust captured by the second screen is removed, the first screen captures the dust.

[0006] However, debris on the first screen may create resistance when returning the second screen to the waterway, potentially preventing the second screen from being installed in its intended position. Furthermore, no specific method for removing debris from the first screen is provided. Furthermore, the pump gate with a screen described in Patent Document 3 simply has the screen attached to the gate, and no specific method for removing debris captured by the screen is provided. It is assumed that if the screen becomes clogged during pump operation, the pump operation must be stopped temporarily, the gate must be raised, and the debris stuck on the screen must be removed. However, since river-surface-mounted gate pumps must function as a backflow prevention gate when the main river is flooded, the gate cannot be raised when the main river is flooded, leaving the debris removal process unable to be performed. Furthermore, the gate pump equipment with water control doors described in Patent Document 4 allows the water control doors to be raised and lowered to prevent backflow in the event that debris becomes entangled in the pump or check valve or an abnormality occurs in the pump and backflow of outside water cannot be prevented.However, it does not allow the dust removal screen to be raised and lowered, nor does it remove debris captured by the screen.

[0007] The present invention was invented against the above technical background and achieves the following objects. The object of the present invention is to provide a river-surface gate pump equipped with a screen, which, by installing a fixed screen and a movable screen on the gate upstream of the submersible pump suction port, eliminates the need to install separate dust removal equipment, such as dust removal equipment on the back side of the river, in a river-surface-installed gate pump, and does not require the securing of land for installing the dust removal equipment. Another object of the present invention is to provide a Kawaomote gate pump equipped with a screen that, when clogged with debris captured on the screen and obstructing the cross section of the water flow, does not require stopping the pump and lifting the gate to remove the debris, but instead takes into consideration measures to prevent the screen from becoming clogged with debris while the pump is running by raising and lowering a movable screen opposite the fixed screen, thereby allowing the pump to be operated continuously for as long as possible without stopping the pump.

[0008] Another object of the present invention is to provide a screen-mounted Kawaomote gate pump that can reduce the space required for installing the gate and the cost of manufacturing the gate and screen by using a drive mechanism for raising and lowering the movable screen, which allows the gate and screen to be used as both a gate and screen. Yet another object of the present invention is to provide a screen-equipped river surface gate pump which, if a pump with excellent debris passage ability is used, does not necessarily have to pull up natural debris such as aquatic plants in rivers with a lot of this debris, and does not have to rake up the debris captured by the movable and fixed screens into the waterway, thereby reducing the cost of debris disposal. Another object of the present invention is to provide a screen-equipped riverside gate pump in which the fixed screen is structured to be freely opened and closed relative to the gate, thereby opening the upstream side of the pump suction port of the pump chamber formed in the gate on which the submersible pump is mounted, thereby making it possible to easily remove debris that has accumulated in the pump chamber. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention employs the following means. That is, the screen-mounted river surface gate pump of the present invention 1 is a gate pump that is installed on the river surface side of a drainage sluice gate and that prevents backflow of external water when the main river is flooded, a gate operating mechanism that drives the gate up and down, a submersible pump that is mounted on the gate and forcibly drains internal water, and a flap valve that is attached to the discharge port of the submersible pump and that prevents backflow of external water when the submersible pump is stopped, a fixed screen that is fixed to the gate upstream of the pump suction port of the submersible pump and that captures debris from the inflowing rainwater; and a movable screen that is arranged on the gate upstream of the fixed screen and parallel to the fixed screen and that captures debris from the inflowing rainwater and that can move up and down. The present invention is characterized by having the following.

[0010] The screen-mounted Kawaomote gate pump of Invention 2 is characterized in that in Invention 1, the gate opening / closing device doubles as an opening / closing device for the raising and lowering movement of the movable screen, using a drive mechanism for the raising and lowering movement of the movable screen. The screen-mounted riverside gate pump of Invention 3 is Invention 1 or 2, and is characterized in that it has a scraper that is provided on the gate and removes the debris on the movable screen when the movable screen is raised and lowered, a rake that is placed below the movable screen and scrapes off the debris on the fixed screen when the movable screen is raised and lowered, and blade members that are placed below and / or at the bottom of the movable screen and crush the debris on the fixed screen when the movable screen is raised and lowered.

[0011] The screen-equipped riverside gate pump of Invention 4 is characterized in that, in Invention 1 or 2, the submersible pump is mounted in each of a plurality of pump chambers separated by partition walls formed in the gate, each pump chamber is equipped with the fixed screen and the movable screen, and a water passage hole is provided in the partition wall to allow water that has passed through the fixed screen of one pump chamber to flow into the other pump chamber. The screen-equipped riverside gate pump of Invention 5 is characterized in that, in Invention 1 or 2, the fixed screen has a structure that can be opened and closed freely relative to the gate so that the upstream side of the pump suction port of the pump chamber can be opened. The screen-mounted river surface gate pump of Invention 6 is characterized in that, in Invention 1 or 2, the movable screen maintains the raising and lowering motion opposite the fixed screen in conjunction with the operation of the submersible pump. [Effects of the Invention]

[0012] The screen-equipped river surface gate pump of the present invention removes debris from the movable and fixed screens by raising and lowering the movable screen for a predetermined period of time while the submersible pump is operating, preventing blockage of the submersible pump and enabling continuous operation of the submersible pump.In addition, the screen-equipped river surface gate pump of the present invention does not require the installation of a separate dust removal facility on the back side of the river, so it can be used in cases where it is difficult to install dust removal facilities because there is no land available on the back side of the river for installing dust removal facilities, or because there is no open channel section and the upstream part of the culvert continues with a culvert-type waterway. Furthermore, the screen-equipped Kawaomote gate pump of the present invention can also be used as an opening / closing device for raising and lowering the gate, thanks to the drive mechanism for raising and lowering the movable screen, thereby reducing the space required for installing the opening / closing device and the cost of manufacturing the opening / closing device.

[0013] Furthermore, if a pump with excellent debris permeability is used for the screen-equipped river surface gate pump of the present invention, there is no need to rake up the debris captured by the movable and fixed screens into the waterway, which makes it possible to reduce the cost of debris disposal. In addition, the screen-equipped riverside gate pump of the present invention has a structure in which the fixed screen can be opened and closed freely relative to the gate, opening the upstream side of the pump suction port of the pump chamber formed in the gate on which the submersible pump is mounted, making it possible to easily remove debris that has accumulated in the pump chamber. Furthermore, by providing a water passage hole in the intermediate partition wall, the screen-equipped riverside gate pump of the present invention can ensure that water flows into one of the pump chambers through the water passage hole even if one of the fixed screens is blocked by debris. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an overall front view of a screen-mounted river surface gate pump according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. [Figure 3]FIG. 3 is an enlarged view of the gate portion of FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along the line BB in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along CC in FIG. [Figure 6] FIG. 6 is an enlarged view of a portion P in FIG. [Figure 7] FIG. 7 is an explanatory diagram showing the dust removal operation of the screen-mounted river surface gate pump according to the first embodiment of the present invention. [Figure 8] FIG. 8 is a view corresponding to FIG. 3 showing a screen-mounted river surface gate pump according to a second embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view taken along line DD in FIG. [Figure 10] FIG. 10 is a view corresponding to FIG. 3 showing a screen-mounted river surface gate pump according to a third embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view taken along the line E-E in FIG. [Figure 12] FIG. 12 is a flow diagram of the electrically operated raising and lowering operation of the movable screens 6A and 6B. [Figure 13] FIG. 13 is a flow diagram showing a branch flow of the flow diagram of FIG. [Figure 14] FIG. 14 is a flow diagram showing branch flows of the flow diagram of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] [First embodiment of the screen-equipped Kawamote gate pump] The following describes an embodiment of the invention. Although one or more submersible pumps are installed on a screen-mounted river surface gate pump, the following embodiment will be described using an example in which two submersible pumps are installed. Figure 1 is a front view of a first embodiment of a screen-equipped river surface gate pump according to the present invention. Figure 2 is a cross-sectional view taken along the line AA in Figure 1. Figure 3 is an enlarged view of the gate in Figure 2. Figure 4 is a cross-sectional view taken along the line BB in Figure 3. As shown in Figure 1, a drainage sluice gate 1, indicated by a two-dot chain line, is installed in a waterway crossing a levee. A gate 2, which prevents backflow of external water during flooding, is supported vertically and movably. The gate 2 is driven vertically by a gate operator 3 at the top of the drainage sluice gate 1. Submersible pumps 4A and 4B are mounted horizontally in parallel on the gate 2 to forcibly drain the internal water. One submersible pump 4A is mounted in one pump chamber 22A, separated by a vertical intermediate partition wall 21 formed on the gate 2, commonly known as the "intermediate stringer." The other submersible pump 4B is mounted in the other pump chamber 22B. Flap valves 41, 41 are attached to the discharge ports of the submersible pumps 4A and 4B to prevent backflow of external water when the pumps are stopped.

[0016] Fixed screens 5A and 5B are fixed to the gate 2 at the pump suction ports of the submersible pumps 4A and 4B, respectively, to capture debris from the incoming rainwater. Also, movable screens 6A and 6B, which can be raised and lowered, are located upstream of the fixed screens 5A and 5B. The movable screens 6A and 6B are parallel to the fixed screens 5A and 5B and capture debris flowing into the fixed screens 5A and 5B. In Figure 1, the left half is a front view from the downstream (main river) side, and the right half is a front (rear) view from the upstream side. The other submersible pump 4B is shown on the left, and one movable screen 6A is shown on the right. Lifting rods 61A and 61B are supported at the top ends of the movable screens 6A and 6B, respectively, and the top ends of the lifting rods 61A and 61B are fixed to a lifting beam 62.

[0017] Lifting beam guides 63A and 63B are fixed to the upper end of gate 2, and lifting beam 62 is guided by lifting beam guides 63A and 63B to allow for lifting and lowering. Suspension rods (rack rods 65A and 65B) are supported on the top of lifting beam 62 via suspending brackets 64A and 64B. The suspension rods of gate opening / closing device 3 include spindle rods and rack rods. However, since this invention is a technology used for a river surface drainage sluice gate, rack rods 65A and 65B are used in this embodiment because they must have a gravity lowering function to quickly close the gate in an emergency and a function to drive the lifting and lowering movement of the movable screen at a certain speed. Rack rods 65A and 65B are driven up and down in synchronization with gate opening / closing device 3 (manual or mechanical). If the rack rods 65A and 65B are driven vertically in synchronization for a predetermined time, the movable screens 6A and 6B will repeatedly rise and fall opposite the fixed screens 5A and 5B, as shown in Figures 7(a) to 7(c).

[0018] As shown in Figures 3, 4, and 6, rakes 67A and 67B are attached to the bottom of the movable screens 6A and 6B. Because the rakes 67A and 67B protrude toward the fixed screens 5A and 5B, as shown in Figure 7(b), when the movable screens 6A and 6B rise toward the fixed screens 5A and 5B, the rakes 67A and 67B scrape off the debris captured by the fixed screens 5A and 5B. Also, as shown in Figures 2 and 3, scrapers 68A and 68B are attached to the gate 2 upstream of the movable screens 6A and 6B, at their uppermost positions when the movable screens 6A and 6B are in their lowered (lowest position). Therefore, as shown in Figure 7(b), when the movable screens 6A and 6B rise toward the fixed screens 5A and 5B, the scrapers 68A and 68B scrape off the debris captured by the movable screens 6A and 6B. The scraped-off debris sticks to the fixed screens 5A and 5B due to the water flow from the submersible pumps 4A and 4B, but when the movable screens 6A and 6B are lowered as shown in Figure 7(c), the rakes 67A and 67B push the debris stuck to the fixed screens 5A and 5B down to the bottom of the fixed screens 5A and 5B, making it possible to ensure the water flow cross-section of the fixed screens 5A and 5B. Also, as shown in Figure 7(c), the debris that passes through the fixed screens 5A and 5B in the process of pushing the movable screens 6A and 6B down to the bottom passes through the submersible pumps 4A and 4B, which have excellent debris permeability, and is released into the open water along with the rainwater.

[0019] As shown in Figures 3 and 6, L-shaped steel blade members 69A and 69B are fixed to the lower and / or bottom of the movable screens 6A and 6B. Therefore, as shown in Figure 7(c), some of the debris that does not pass through the fixed screens 5A and 5B but is pushed down to the bottom of the fixed screens 5A and 5B is sandwiched between the blade members 69A and 69B and the lower cross beam 23 of the gate 2 and cut off, allowing some of the cut debris to pass through the fixed screens 5A and 5B. The passed debris then passes through the submersible pumps 4A and 4B, which have excellent debris permeability, and is discharged into the open water along with rainwater. This reduces the amount of debris remaining on the fixed screens 5A and 5B and ensures a sufficient water flow cross section.

[0020] As shown in Figures 4 and 5, the intermediate partition wall 21 formed between the lower cross beam 23 and the intermediate cross beam 27 has an oval water passage hole 24 formed therein, and a reinforcing rib 25 is formed around the water passage hole 24. As described above, the intermediate partition wall 21 separates the pump chambers 22A and 22B. If the intermediate partition wall 21 did not have the water passage hole 24, and the fixed screens 5A and 5B of one of the pump chambers 22A and 22B were clogged with debris, the amount of water flowing into one of the pump chambers 22A and 22B would decrease, potentially causing problems with the pump operation of one of the submersible pumps 4A and 4B. However, by providing the above-mentioned water passage hole 24 in the intermediate partition wall 21, water flows from the other pump chamber 22A, 22B to one of the pump chambers 22A, 22B through the water passage hole 24, making it possible to ensure the amount of water flowing into one of the submersible pumps 4A, 4B, thereby eliminating the risk of disruption to pump operation.

[0021] When the rack rods 65A and 65B are raised, the movable screens 6A and 6B rise toward the fixed screens 5A and 5B. Then, when the rack rods 65A and 65B are further raised, the lifting beam 62 abuts against the stoppers 66 at the upper ends of the lifting beam guides 63A and 63B, and the gate 2 is guided by the drainage sluice gate 1 and rises. Therefore, the gate operating mechanism 3 for raising and lowering the gate 2 can also be used as the operating mechanism for raising and lowering the movable screen 6A and 6B, thereby reducing the space required for installing the operating mechanism and the cost of manufacturing the operating mechanism. Figures 7(a) to 7(c) are explanatory diagrams showing the debris removal operation of the screen-equipped riverside gate pump of the first embodiment of the present invention.

[0022] According to the screen-equipped river surface gate pump of the first embodiment of the present invention, by raising and lowering the movable screens 6A and 6B for a predetermined period of time while the submersible pumps 4A and 4B are operating, debris is removed from the movable screens 6A and 6B and the fixed screens 5A and 5B, preventing blockage of the submersible pumps 4A and 4B and enabling continuous operation of the submersible pumps 4A and 4B. Furthermore, according to the screen-equipped river surface gate pump of the first embodiment of the present invention, there is no need to secure land for the installation of separate dust removal equipment on the back side of the river, and by using the submersible pumps 4A and 4B, which have excellent debris permeability, there is no need to shovel the debris captured by the movable screens 6A and 6B and the fixed screens 5A and 5B up into the waterway, thereby reducing the cost of debris treatment.

[0023] The above-mentioned raising and lowering operation of the movable screens 6A and 6B is either manual or electrically operated. This describes the basic operation of the movable screens 6A and 6B when there is no resistance from debris trapped on the fixed screens 5A and 5B. Note that the flow diagrams shown in Figures 12 through 14 are conceivable when the movable screens 6A and 6B are raised and lowered electrically. Even if resistance from debris trapped on the fixed screens 5A and 5B occurs during the raising and lowering operation, these flow diagrams allow the movable screens 6A and 6B to be raised and lowered while avoiding (eliminating) the resistance during pump operation. The basic flow shown in Figure 12 is further divided into two parts: branch flow A (Figure 13), which is the processing flow when resistance from debris occurs during the raising of the movable screens 6A and 6B, and branch flow B (Figure 14), which is the processing flow when resistance from debris occurs during the lowering of the movable screens 6A and 6B. Specifically, resistance caused by debris is avoided (eliminated) in each of branch flows A and B, and the debris is fed back to the basic flow for processing. This allows the movable screens 6A and 6B to repeatedly rise and fall opposite the fixed screens 5A and 5B for a specified period of time while the pump is operating.

[0024] (1) In the basic flow, the movable screens 6A and 6B are repeatedly raised and lowered opposite the fixed screens 5A and 5B in conjunction with the pump operation during pump operation. The operation buttons for the movable screens 6A and 6B on the control panel (not shown) are pressed to start operation. S1 checks whether the pump is operating. When the pump starts operating, the movable screens 6A and 6B are at their lowest limit position. Therefore, if the pump is operating at S1, the raising operation begins at S2. The raising operation continues until the set raising torque is reached at S3 (for example, a current value that applies a load at the upper limit position is set and the current value during operation is measured), and when the set raising torque is reached at S3, the raising operation is stopped at S4. If the screens are at their upper limit position at S5 (for example, measured with an upper limit switch), the movable screens 6A and 6B begin lowering at S6.

[0025] If the screens 6A and 6B are not at the upper limit in S5, it is determined that resistance due to debris has occurred in the movable screens 6A and 6B, and processing proceeds to branch flow A. The lowering operation continues until the set lowering torque is reached in S7 (for example, a current value that applies a load at the lower limit position is set and the current value during operation is measured). When the set lowering torque is reached in S7, the lowering operation is stopped in S8. If the screens are at the lower limit in S9 (for example, measured with a lower limit switch), processing returns to S1, where it is confirmed whether the pump is operating, and the processes of S1 to S9 are repeated to repeatedly raise and lower the movable screens 6A and 6B. If the screens are not at the lower limit in S9, it is determined that resistance due to debris has occurred in the movable screens 6A and 6B, and processing proceeds to branch flow B. If the pump operation is stopped in S1, the movable screens 6A and 6B stop raising and lowering and remain at the lower limit position, and processing ends.

[0026] (2) Branch flow A processes the debris that creates resistance on the movable screens 6A and 6B during the upward movement. In S10, the movable screens 6A and 6B begin lowering. In S11, the lowering continues until the set lowering torque is reached, and when the set lowering torque is reached in S11, the lowering stops in S12. If the screens are at the lowest position in S13, the process returns to branch 1 of the basic flow. If the screens are not at the lowest position in S13, it is checked in S14 whether the pump is operating. If the pump is operating in S14, the screens begin raising in S15. If the pump has stopped operating in S14, an error message such as "Dust resistance at bottom" is displayed on the control panel in S16, and the process ends. Thereafter, the cause of the error is manually resolved.

[0027] In S17, the movable screens 6A and 6B continue to rise up to the set rise torque, and when the set rise torque is reached in S17, the rise operation is stopped in S18. If the screens are at the upper limit position in S19, the process returns to branch 2 of the basic flow. If the screens are not at the upper limit position in S19, it is checked in S20 whether the pump is running. If the pump is running in S20, the process moves to branch 3 of branch flow A. If the pump has stopped running in S20, an error message such as "Resistance to dust on top" is displayed on the control panel in S21, and the process ends. Thereafter, the cause of the error is manually resolved.

[0028] (3) Branch flow B processes the debris that causes resistance to the movable screens 6A and 6B during the downward movement. In S22, the movable screens 6A and 6B begin to rise. The rising operation continues until the set rising torque is reached in S22, and when the set rising torque is reached in S23, the rising operation is stopped in S24. If the screens are at the upper limit position in S25, the process returns to branch 2 of the basic flow. If the screens are not at the upper limit position in S25, it is checked in S26 whether the pump is operating. If the pump is operating in S26, the screens begin to fall in S27. If the pump operation is stopped in S26, an error message such as "Dust resistor on top" is displayed on the control panel in S28, and the process ends. After that, the cause of the error is manually resolved.

[0029] In S29, the movable screens 6A and 6B continue to lower until the set lowering torque is reached, and when the set lowering torque is reached in S29, the lowering operation is stopped in S30. If the screens are at the lowest position in S31, the process returns to branch 1 of the basic flow. If the screens are not at the lowest position in S31, it is checked in S32 whether the pump is running. If the pump is running in S32, the process moves to branch 4 of branch flow B. If the pump has stopped running in S32, an error message such as "Debris resistance at bottom" is displayed on the control panel in S33, and the process ends. Thereafter, the cause of the error is manually resolved. According to the basic flow, branch flow A, and branch flow B described above, while the pump is running, resistance caused by debris is avoided (eliminated), and the movable screens 6A and 6B repeatedly rise and fall against the fixed screens 5A and 5B, thereby preventing clogging of the screens.

[0030] [Second embodiment of the screen-equipped Kawamote gate pump] Next, we will explain a second embodiment of a riverside gate pump equipped with a screen. This embodiment relates to maintenance after the pump has stopped operating, particularly the removal of debris accumulated in the pump chamber. First, debris accumulated in the pump chamber narrows the space between pump chambers 22A and 22B, potentially impeding water flow during pump operation. Second, debris accumulated in pump chambers 22A and 22B may be sucked into submersible pumps 4A and 4B during pump operation, potentially blocking the pumps. Third, there is a risk of odors being generated by debris accumulated in pump chambers 22A and 22B. To address these issues, this example simplifies the removal of debris accumulated in pump chambers 22A and 22B after passing through a fixed screen.

[0031] FIG. 8 is a view equivalent to FIG. 3 showing a screen-equipped river surface gate pump according to a second embodiment of the present invention, and FIG. 9 is a DD cross-sectional view of FIG. 8. Specifically, in the first embodiment, fixed screens 5A and 5B are fixedly fitted to gate 2 (i.e., the outer periphery or four corners of the fixed screen are firmly fixed with bolts or the like), making it difficult to remove debris accumulated in pump chambers 22A and 22B. Furthermore, river surface-mounted gate pumps must function as backflow prevention gates when the main river (external water) is flooded, making it impossible to remove debris by lifting the gate when the main river (external water) is flooded. However, the screen-equipped river surface gate pump of the present application, with its structure in which the fixed screen is freely attached to gate 2 to be opened and closed as described in the second and third embodiments below, prevents backflow from the main river (external water) while still enabling the removal of debris accumulated in pump chambers 22A and 22B. This will be explained in detail below. In the second embodiment, a fixed screen is attached to the gate 2 so as to be openable and closable (vertically rotatable). As shown in Figures 8 and 9, the lower ends of the fixed screens 7A and 7B are supported on the upper part of the lower cross beam 23 so as to be rotatable in a vertical plane (in a plane parallel to the paper surface) around horizontal rotation axes 71. The upper ends of the fixed screens 7A and 7B are detachably attached to support brackets 271 on the underside of the intermediate cross beam 27 with bolts 272.

[0032] To remove debris trapped in pump chambers 22A and 22B, first stop the submersible pumps 4A and 4B. Next, operate the gate operating mechanism 3 to raise the movable screens 6A and 6B using the rack rods 65A and 65B. Then, loosen the bolts 272 and rotate the fixed screens 7A and 7B clockwise around the rotating shafts 71 to the upstream position shown by the two-dot chain line in the vertical plane. This opens the upstream pump suction ports of pump chambers 22A and 22B, allowing debris trapped in pump chambers 22A and 22B to be easily removed manually at any time. As a result, it is possible to eliminate the cause of water flow obstruction caused by accumulated debris narrowing the space in pump chambers 22A, 22B, and also to prevent the debris accumulated in pump chambers 22A, 22B from being sucked into submersible pumps 4A, 4B all at once, blocking the submersible pumps 4A, 4B, and also to prevent the occurrence of foul odors caused by debris accumulated in pump chambers 22A, 22B, thereby solving the problem of debris accumulated in pump chambers 22A, 22B. Once this work is completed, the normal debris removal operation described in Figures 7(a) to 7(c) is performed in conjunction with pump operation.

[0033] [Third embodiment of the screen-equipped Kawamote gate pump] Next, a third embodiment of a screen-equipped river-surface gate pump will be described. Fig. 10 is a view equivalent to Fig. 3 showing a screen-equipped river-surface gate pump according to the third embodiment of the present invention, and Fig. 11 is an E-E cross-sectional view of Fig. 10. Like the screen-equipped river-surface gate pump according to the second embodiment, the third embodiment facilitates the removal of debris that has passed through the fixed screen and accumulated in the pump chambers 22A and 22B. In the third embodiment, the fixed screen is attached to the gate 2 so as to be freely opened and closed (rotatable horizontally). As shown in Figs. 10 and 11, the lower ends of the fixed screens 8A and 8B are journaled on a rotation shaft 81 perpendicular to the upper part of the lower cross beam 23 (or bracket 233), and the upper ends of the fixed screens 8A and 8B are journaled on a rotation shaft 82 perpendicular to the lower part of the intermediate cross beam 27 (or bracket 273), allowing rotation about the rotation shafts 81 and 82 in a horizontal plane. The upper and lower ends of the fixed screens 8A and 8B are detachably attached to the lower surface of the intermediate cross beam 27 and the upper surface of the lower cross beam 23 with bolts (not shown).

[0034] To remove debris accumulated in the pump chambers 22A and 22B, first stop the submersible pumps 4A and 4B. Next, operate the gate operating mechanism 3 to raise the movable screens 6A and 6B using the rack rods 65A and 65B. Then, loosen the bolts (not shown) and rotate the fixed screen 8A counterclockwise around the rotating shafts 81 and 82 to the upstream position indicated by the two-dot chain line in the horizontal plane. Rotate the fixed screen 8B clockwise to the upstream position indicated by the two-dot chain line in the horizontal plane. This opens the upstream pump suction ports of the pump chambers 22A and 22B, allowing debris accumulated in the pump chambers 22A and 22B to be easily removed manually at any time. As a result, the problem of debris accumulation in the pump chambers 22A and 22B can be resolved, as in the second embodiment described above.

[0035] Other Embodiments Although the embodiments of the present invention have been described above, the present invention is not limited to these examples. For example, in the second and third embodiments described above, fixed screens 7A, 7B, 8A, and 8B are rotated about rotation shaft 71 or rotation shafts 81 and 82 to open the upstream sides of the pump suction ports of pump chambers 22A and 22B. However, fixed screens 7A, 7B, 8A, and 8B may be designed to be easily detachable from gate 2. [Explanation of symbols]

[0036] 1…Drainage gutter gate 2...Gate 21...Intermediate partition wall 22A, 22B...Pump room 23...Lower crossbeam 233…Bracket 24...Water passage hole 25...Reinforcing rib 27...Intermediate crossbeam 271...Support bracket 272...volts 273…Bracket 3...Gate opener 4A, 4B...Submersible pump 41...Flap valve 5A, 5B...Fixed screen 6A, 6B... Movable screen 61A, 61B...Lifting rod 62...Lifting beam 63A, 63B...Lifting beam guide 64A, 64B...Hanging hardware 65A, 65B...Rack rod 66...Stopper 67A, 67B...Rake 68A, 68B...Scraper 69A, 69B...Blade members 7A, 7B...Fixed screen 71...Rotation axis 8A, 8B...Fixed screen 81, 82...Rotation axis

Claims

1. It is a gate installed on the river side of the drainage sluice gate to prevent backflow of external water when the main river floods. a gate opening / closing device that drives the gate up and down; a submersible pump mounted on the gate for forcibly draining water inside; a flap valve attached to the discharge port of the submersible pump to prevent backflow of external water when the submersible pump is stopped; In a gate pump consisting of a fixed screen fixed to the gate upstream of the pump suction port of the submersible pump for capturing debris from the inflowing rainwater; a movable screen that is arranged in parallel with the fixed screen and on the upstream side of the fixed screen at the gate, captures the garbage from the inflowing rainwater, and can move up and down; A screen-mounted river surface gate pump characterized by having:

2. 2. The screen-mounted river surface gate pump according to claim 1, The gate opening / closing device also serves as an opening / closing device for the raising and lowering operation of the movable screen by using a drive mechanism for the raising and lowering operation of the movable screen. A screen-equipped Kawao gate pump characterized by:

3. The screen-mounted river surface gate pump according to claim 1 or 2, a scraper provided on the gate for removing the debris on the movable screen during the raising and lowering operation of the movable screen; a rake disposed below the movable screen and configured to scrape off the debris on the fixed screen during the raising and lowering of the movable screen; a blade member disposed at the lower part and / or bottom of the movable screen, which crushes the garbage on the fixed screen during the upward and downward movement of the movable screen; A screen-mounted river surface gate pump characterized by having:

4. The screen-mounted river surface gate pump according to claim 1 or 2, The submersible pump is mounted in each of a plurality of pump chambers separated by partition walls formed in the gate, and each pump chamber is equipped with the fixed screen and the movable screen, and a water passage hole is provided in the partition wall to allow water that has passed through the fixed screen of one pump chamber to flow into the other pump chamber. A screen-equipped Kawao gate pump characterized by:

5. The screen-mounted river surface gate pump according to claim 1 or 2, The fixed screen is structured to be openable and closable relative to the gate so that the upstream side of the pump suction port of the pump chamber can be opened. A screen-equipped Kawao gate pump characterized by:

6. The screen-mounted river surface gate pump according to claim 1 or 2, The movable screen maintains the raising and lowering motion opposite the fixed screen in conjunction with the operation of the submersible pump. A screen-equipped Kawao gate pump characterized by:

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