Dredging Equipment

Abstract

To suppress pollution of a work water area and collect deposited sediment at a place where water is deep.SOLUTION: A dredging device comprises: a first housing 40 disposed underwater; a first force feed pump 42 disposed inside the first housing 40; a sediment suction pipe 14 that is provided on the first housing 40 and has a tip disposed on a bottom B underwater; a second housing 50 disposed above the first housing 40; a second force feed pump 52 disposed inside the second housing 50; a vacuum suction device 24 disposed on the water; a first vacuum suction path 26 connecting the vacuum suction device 24 and the first housing 40; a second vacuum suction path 28 connecting the vacuum suction device 24 and the second housing 50; a first force feed path 30 connecting the first force feed pump 42 and the second housing 50 and forcibly feeding deposited sediment in the first housing 40 to the second housing 50; and a second force feed path 32 connecting the second force feed pump 52 and the second vacuum suction path 28 and forcibly feeding deposited sediment D in the second housing 50 to the second vacuum suction path 28.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to dredging equipment. [Background technology]

[0002] Known dredging methods for removing sediment deposited at the bottom of rivers, canals, lakes, dam reservoirs, pump sedimentation basins, etc. include fluid transport using an underwater sand pump (see Patent Document 1), air current transport using a vacuum generator (see Patent Document 2), and air current transport using a vacuum generator and a pressure pump (see Patent Document 3). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-47522 [Patent Document 2] Japanese Patent Application Publication No. 2018-158277 [Patent Document 3] Japanese Patent Publication No. 2020-45661 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the dredging method in Patent Document 1 involves rotating a stirring screw (rotor) to excavate and stir the sediment and then suck it up, which can recover the sediment at the bottom of the water, but it also pollutes the working waters. As a result, turbid water may be released from the dam reservoir, and there are concerns that the turbid water released from the dam reservoir into rivers and the sea may have a negative impact on the fishing industry. Furthermore, when using a vacuum generator to suck sediment from the bottom of the water and transport it to a recovery tank above, as in Patent Document 2, the Torricelli principle stipulates that the lift must be 10 m (760 mmHg) or less even under absolute vacuum conditions. Therefore, as the lift increases, the vacuum suction effect decreases, making it difficult to transport mud and sediment with high specific gravity and viscosity. Furthermore, when using a vacuum generator and a pressure pump together to transport sediment deposited at the bottom of the water to a recovery tank as in Patent Document 3, the sediment can be transported to the housing if the lift from the bottom of the water to the casing by the suction of the vacuum generator is set to 10 m or less; however, if the lift from the casing to the recovery tank becomes too high, the transporting power of the pressure pump may also decrease. The present invention has been made in consideration of the above circumstances, and aims to provide a dredging device that is advantageous in suppressing pollution of working waters and recovering sediment deposited in deep water areas. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, one embodiment of the present invention is a dredging device for recovering sediment deposited on the bottom of water, comprising: a first housing placed underwater; a first pressure pump placed inside the first housing; a sediment suction pipe provided in the first housing and whose tip is placed at the bottom of the water; a second housing placed above the first housing; a second pressure pump placed inside the second housing; a vacuum suction device placed on the water; a first vacuum suction line connecting the vacuum suction device to the first housing; a second vacuum suction line connecting the vacuum suction device to the second housing; a first pressure transfer line connecting the first pressure transfer pump to the second housing and pressurizing the sediment in the first housing to the second housing; and a second pressure transfer line connecting the second pressure transfer pump to the second vacuum suction line and pressurizing the sediment in the second housing to the second vacuum suction line. Furthermore, one embodiment of the present invention is characterized in that the vacuum suction device is single, the second vacuum suction path is connected to the first vacuum suction path above the second housing, and the first vacuum suction path from the connection point of the second vacuum suction path to the vacuum suction device also serves as the second vacuum suction path. Furthermore, one embodiment of the present invention is characterized in that the vacuum suction device is single, the second housing is interposed in the middle of the first vacuum suction path, the first vacuum suction path is configured to include the second housing, and the first vacuum suction path from the second housing to the vacuum suction device also serves as the second vacuum suction path. In addition, one embodiment of the present invention is characterized in that the vacuum suction device is a single device and further comprises at least one third housing arranged between the first housing and the second housing, a third pressure-feed pump arranged inside the third housing, and a third pressure-feed line connecting the third pressure-feed pump to the second housing and pressure-feeding the deposited sediment in the third housing to the second housing, wherein the second housing and the third housing are interposed in the middle of the first vacuum suction line, the first vacuum suction line includes the second housing and the third housing, the first pressure-feed line connects the first pressure-feed pump to the second housing via the third pressure-feed pump and the third pressure-feed line and pressure-feeds the deposited sediment in the first housing to the second housing, and the first vacuum suction line from the second housing to the vacuum suction device also serves as the second vacuum suction line. Furthermore, one embodiment of the present invention further comprises a recovery tank that is interposed midway along the first vacuum suction path and placed on the water to recover sediment, and the height from the bottom of the water to the lower end of the first housing, the height from the lower end of the first housing to the lower end of the second housing, and the height from the lower end of the second housing to the connection position of the first vacuum suction path of the recovery tank are each 6m to 9m. Furthermore, one embodiment of the present invention is characterized in that it further comprises a first air intake pipe provided in the first housing and supplying air to the inside of the first housing, and a second air intake pipe provided in the second housing and supplying air to the inside of the second housing. Furthermore, one embodiment of the present invention further comprises a recovery tank that is interposed in the middle of the first vacuum suction path and placed on the water to recover sediment, and is characterized in that the height from the bottom of the water to the lower end of the first housing, the height from the lower end of the first housing to the lower end of the third housing, the height from the lower end of the third housing to the lower end of the second housing, and the height from the lower end of the second housing to the connection position of the first vacuum suction path of the recovery tank are each 6m to 9m. Furthermore, one embodiment of the present invention is characterized in that it further comprises a first air intake pipe provided in the first housing and supplying air to the inside of the first housing, a second air intake pipe provided in the second housing and supplying air to the inside of the second housing, and a third air intake pipe provided in the third housing and supplying air to the inside of the third housing. [Effects of the Invention]

[0006] According to one embodiment of the present invention, the dredging operation is carried out by sucking sediment from a first housing that is placed underwater and has a first pressure pump disposed therein, and a second housing that is placed above the first housing and has a second pressure pump disposed therein, and then using a vacuum suction device to suck up the sediment through a sediment suction pipe and a first vacuum suction line and transporting it to the first housing, and then using the first pressure pump to pump the sediment from the first housing through the first pressure line to the second housing, and then using the second pressure pump to pump the sediment from the second housing through the second pressure line to the second vacuum suction line, thereby preventing pollution of the working water area and being advantageous for recovering sediment from deep waters. Furthermore, if the second vacuum suction path is connected to the first vacuum suction path above the second housing, and the first vacuum suction path from the connection point of the second vacuum suction path to the vacuum suction device also serves as the second vacuum suction path, the first vacuum suction path can connect the first housing and the vacuum suction device without going through the second housing, which is advantageous in increasing the suction force of the vacuum suction device. Furthermore, if the second housing is interposed in the middle of the first vacuum suction path so that the first vacuum suction path includes the second housing, the dredging device can be configured simply and this is advantageous in terms of reducing costs. Furthermore, if the height from the bottom of the water to the lower end of the first housing, the height from the lower end of the first housing to the lower end of the second housing, and the height from the lower end of the second housing to the connection position of the first vacuum suction path of the recovery tank are each set to 6m to 9m, this is advantageous in increasing the lift from the bottom of the water while suppressing a decrease in the conveying force of the first pressure pump and the second pressure pump. Furthermore, if the first housing is provided with a first air supply pipe that supplies air to the inside of the first housing, and the second housing is provided with a second air supply pipe that supplies air to the inside of the second housing, the pressure on the vacuum suction path and the pressure transport path can be adjusted, which is advantageous in increasing the transport force of the deposited sediment. In addition, by placing at least one third housing equipped with a third pressure pump between the first and second housings, and pressurizing the sediment in the first housing to the third housing, and then pressurizing the sediment in the third housing to the second housing, it is advantageous to increase the lift from the bottom of the water while maintaining the transport force of the sediment. Furthermore, if the height from the bottom of the water to the lower end of the first housing, the height from the lower end of the first housing to the lower end of the third housing, the height from the lower end of the third housing to the lower end of the second housing, and the height from the lower end of the second housing to the connection position of the first vacuum suction path of the recovery tank are each set to 6m to 9m, this is advantageous in increasing the lift from the bottom of the water while suppressing a decrease in the conveying force of the first pressure pump, second pressure pump, and third pressure pump. Furthermore, if the first housing is provided with a first air supply pipe for supplying air to the inside of the first housing, the second housing is provided with a second air supply pipe for supplying air to the inside of the second housing, and the third housing is provided with a third air supply pipe for supplying air to the inside of the third housing, the pressure on the vacuum suction path and the pressure transport path can be adjusted, which is advantageous in increasing the transport force of the deposited sediment. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a schematic diagram showing a dredging device of a first embodiment. FIG. [Figure 2] FIG. 2 is an explanatory diagram of the layout of a relay pump unit of the dredging equipment of the first embodiment. [Figure 3] FIG. 10 is an explanatory diagram of the arrangement of a relay pump unit of the dredging equipment of the second embodiment. [Figure 4] FIG. 10 is an explanatory diagram of the layout of a relay pump unit of the dredging equipment of the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] (First embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The dredging device 10A of the first embodiment is configured to collect and dredge sediment deposited on the underwater bottom of rivers, canals, lakes, dam reservoirs, pump settling basins, and the like. The sediment contains sludge, mud, and the like, which have high specific gravity and viscosity, and the dredging device 10A consistently and continuously performs underwater suction, vertical transport, and horizontal transport of the sediment. In the first embodiment, the dredging device 10A dredges sediment D accumulated on the bottom B of a dam reservoir W.

[0009] As shown in Figures 1 and 2, the dredging device 10A is configured to include a first relay pump unit 12, a sediment suction pipe 14, an auger-equipped suction machine 16, a second relay pump unit 18, a recovery tank 20, a filter 22, a vacuum suction device 24, a first vacuum suction line 26, a second vacuum suction line 28, a first pressure conveying line 30, a second pressure conveying line 32, a conveying pump 34, and recovered sediment treatment equipment 36 (vibrating screen, turbid water treatment equipment, sedimentation basin, etc.). The recovery tank 20, filter 22, vacuum suction device 24, transfer pump 34, and recovered soil treatment equipment 36 are located on land (or on water).

[0010] The first relay pump unit 12 is configured to include a first housing 40, a first pressure pump 42, a first air supply pipe 44, and a vacuum gauge 46. The first housing 40 is rectangular parallelepiped-shaped and watertight, and is placed underwater in the dam reservoir W. The first housing 40 is suspended so as to be able to rise and fall by a wire rope 9202 of a gate-shaped facility 92 installed on a barge 90, and the soil suction pipe 14 and the auger-equipped suction machine 16 attached to the first housing 40 are lowered to the bottom B of the dam reservoir W as the first housing 40 descends. The first pressure pump 42 is disposed inside the first housing 40, and pressure-feeds the sediment D inside the first housing 40 upward through a first pressure path 30, which will be described later. The first air supply pipe 44 is provided in the first housing 40 and supplies air to the inside of the first housing 40 . Specifically, in this embodiment, the first air intake pipe 44 has one end attached to the top surface of the first housing 40 and the other end extending upward from the first housing 40 positioned above the water, so as to be able to take in air. The first air supply pipe 44 is provided with an opening / closing valve (not shown), and by controlling this opening / closing valve, the pressure to the first vacuum suction path 26 and the first pressure feed path 30 can be adjusted, and the deposited sediment D can be transported from the first housing 40 to the second housing 50 while maintaining a predetermined transport amount. The vacuum gauge 46 is an instrument that measures the pressure (negative pressure) inside the first housing 40.

[0011] The sediment suction pipe 14 is provided in the first housing 40, and its tip is placed at the bottom B underwater. Specifically, the rear end of the sediment suction pipe 14 is attached to the bottom surface of the first housing 40, and an inclined suction port 1402 is provided at the tip extending downward from the first housing 40, and the suction port 1402 is positioned so that it can be inserted into the underwater bottom B of the dam reservoir W. The soil suction pipe 14 sucks the accumulated soil D excavated by the auger-equipped suction machine 16 and transports it to the first housing 40.

[0012] The auger-equipped suction machine 16 is provided near the tip of the sediment suction pipe 14, and excavates and breaks up the sediment D accumulated on the underwater bottom B, and is configured with an excavation blade 1602 (auger). The excavation blade 1602 rotates when a driving force from a motor (not shown) is transmitted to it. The auger-equipped suction machine 16 can be any of various known excavators, such as the excavator described in JP 2021-32005 A.

[0013] The second relay pump unit 18 is configured to include a second housing 50, a second pressure pump 52, a second air supply pipe 54, and a vacuum gauge 56. The second housing 50 is rectangular parallelepiped-shaped and watertight, and is disposed above the first housing 40. The second housing 50 in this embodiment is placed on a slope on land, but like the first housing 40, it may be suspended by a gate-type facility or the like. Furthermore, the second housing 50 may be placed on the water surface of the dam reservoir W or on the barge 90, or may be placed underwater in the dam reservoir W, as long as it is above the first housing 40. The second pressure pump 52 is disposed inside the second housing 50, and pressure-feeds the sediment D inside the second housing 50 upward through a second pressure path 32, which will be described later. The second air supply pipe 54 is provided in the second housing 50 and supplies air to the inside of the second housing 50 . Specifically, in this embodiment, one end of the second air intake pipe 54 is attached to the upper surface of the second housing 50, extends upward from the second housing 50, and is installed so as to take in air. The second air supply pipe 54 is provided with an opening / closing valve (not shown), and by controlling this opening / closing valve, the pressure to the second vacuum suction path 28 and the second pressure feed path 32 can be adjusted, and the deposited sediment D can be transported from the second housing 50 to the recovery tank 20 while maintaining a predetermined transport amount. The vacuum gauge 56 is an instrument that measures the pressure (negative pressure) inside the second housing 50.

[0014] The recovery tank 20 is disposed on land (or water) in the middle of a first vacuum suction line 26 (described later), and recovers the sediment D that has been sucked and transported by the first vacuum suction line 26. The recovered sediment D is discharged to a recovered sediment treatment facility 36 by a transport pump 34. The recovery tank 20 has a function of being able to continuously perform the suction of the sediment D by the first vacuum suction path 26 and the discharge of the recovered sediment D in parallel. The recovered sediment treatment facility 36 can be any of a variety of conventionally known facilities, such as a solid-liquid separator that separates the transported sediment D into solids and water. The separated solids are transported to a sand removal area or used for landfill, and the separated water is purified, for example, in a wastewater treatment facility, and then returned to the dam reservoir W.

[0015] The vacuum suction device 24 is, for example, a single vacuum pump that is placed on land (or water) and sucks the sediment suction pipe 14, the first vacuum suction path 26, and the second vacuum suction path 28 through the filter 22. This maintains a negative pressure inside the sediment suction pipe 14, the first housing 40, the first vacuum suction path 26, the second housing 50, the second vacuum suction path 28, and the recovery tank 20.

[0016] The first vacuum suction path 26 is a suction path formed by a vacuum suction pipe that connects the vacuum suction device 24 and the first housing 40. The second vacuum suction path 28 is a suction path formed by a vacuum suction pipe that connects the vacuum suction device 24 and the second housing 50. The second vacuum suction path 28 is connected to the first vacuum suction path 26 above the second housing 50, and the first vacuum suction path 26 from the connection point of the second vacuum suction path 28 to the vacuum suction device 24 also serves as the second vacuum suction path 28. A recovery tank 20 and a filter 22 are interposed in the middle of the first vacuum suction path 26, which also serves as the second vacuum suction path 28.

[0017] The first pressure-feeding path 30 is a pressure-feeding path formed by a pressure-feeding pipe connecting the first pressure-feeding pump 42 and the second housing 50, and pressure-feeds the sediment D inside the first housing 40 to the second housing 50. A pressure-transfer path formed by a pressure-transfer pipe connecting the second pressure-transfer path 32, the second pressure-transfer pump 52, and the second vacuum suction path 28, which pressure-transfers the sediment D accumulated in the second housing 50 to the second vacuum suction path 28.

[0018] Next, the transportation and lifting range of the sediment D from the underwater bottom B of the dam reservoir W to the recovery tank 20 by the dredging device 10A of this embodiment will be described. As mentioned above, when using a vacuum suction device to suck up sediment from the bottom of the water and transport it to a recovery tank above, Torricelli's principle dictates that a lift of 10 m or less is preferable, even under absolute vacuum conditions. Also, when using a vacuum suction device and a pressure pump together, the sediment can be transported to the housing if the lift from the bottom of the water to the housing by the vacuum suction device is set to 10 m or less, but if the lift from the housing to the recovery tank is high, the transport power of the pressure pump may also decrease, although this depends on the performance. Therefore, in this embodiment, the deposited sediment D is sucked from the bottom of the dam reservoir W to the first housing 40 by a vacuum suction device 24, and then pressurized and transported from the first housing 40 to the second housing 50 by a first pressure pump 42, and from the second housing 50 to the recovery tank 20 by a second pressure pump 52. The height h1 from the underwater bottom B to the lower end of the first housing 40, the height h2 from the lower end of the first housing 40 to the lower end of the second housing 50, and the height h3 from the lower end of the second housing 50 to the connection position of the first vacuum suction path 26 of the recovery tank 20 are each set to 6m to 9m. Therefore, in this embodiment, the distance from the bottom B of the dam reservoir W to the recovery tank 20 is divided into sections of 6 to 9 m, and the sediment D is transported using a vacuum suction device 24 and two pressure pumps 42, 52, making it easy to transport the sediment D to the recovery tank 20. That is, the dredging device 10A of this embodiment is suitable when the height H1 from the bottom B of the dam reservoir W to the recovery tank 20 has a head of 18 m to 27 m. Also, since large pressure pumps are expensive, costs can be reduced by arranging multiple small pressure pumps as in this embodiment.

[0019] Next, the flow of dredging work by the dredging apparatus 10A of this embodiment will be described. By connecting a vacuum suction pipe and a pressure feed pipe to the first relay pump unit 12 and the second relay pump unit 13, a first vacuum suction path 26, a second vacuum suction path 28, a first pressure feed path 30, and a second pressure feed path 32 are formed. The barge 90 is moved above the bottom B of the dam reservoir W from which the deposited sediment D is to be collected and stopped, and the first relay pump unit 12, which is equipped with a sediment suction pipe 14 and an auger-equipped suction machine 16, is lowered toward the bottom B of the dam reservoir W using the wire rope 9202 of the gate-shaped equipment 92. When the digging blade 1602 of the auger-equipped suction machine 16 reaches the bottom B of the dam reservoir W, the vacuum suction device 24 sucks water from the suction port 1402 of the sediment suction pipe 14, generating a water flow toward the suction port 1402. Then, a motor (not shown) is driven to rotate the digging blade 1602, which excavates and breaks up the accumulated sediment D, and the vacuum suction device 24 sucks the accumulated sediment D through the sediment suction pipe 14. The accumulated sediment D sucked by the sediment suction pipe 14 is transported to the inside of the first housing 40 and collected.

[0020] Next, the sediment D collected inside the first housing 40 is pumped by the first pressure pump 42 and transported through the first pressure path 30 into the second housing 50, where the sediment D is collected. When the sediment D is transported to the second housing 50, the sediment D collected inside the second housing 50 is pumped by the second pressure pump 52 and transported through the second pressure path 32 toward the second vacuum suction path 28, where it merges with the second vacuum suction path 28. The merged sediment D is then transported by the vacuum suction device 24 and the second pressure pump 52 through the second vacuum suction path 28 (first vacuum suction path 26) to the recovery tank 20. Meanwhile, a portion of the sediment D recovered inside the first housing 40 by the vacuum suction device 24 is transported to the recovery tank 20 through the first vacuum suction path 26 and the second vacuum suction path 28. That is, the sediment D sucked and transported by the vacuum suction device 24 and the sediment D pressurized by the first pressure pump 42 and the second pressure pump 52 join together at the connection point between the second pressure path 32 and the second vacuum suction path 28 and are transported to the recovery tank 20. The sediment D collected in the collection tank 20 is then discharged to the collected sediment treatment facility 36, where it is separated into solids and water and subjected to a predetermined treatment.

[0021] Thus, the dredging device 10A of the first embodiment comprises a first housing 40 that is disposed underwater and has a first pressure pump 42 disposed therein, and a second housing 50 that is disposed above the first housing 40 and has a second pressure pump 52 disposed therein, and is provided with a first vacuum suction passage 26 that connects the vacuum suction device 24 to the first housing 40, a second vacuum suction passage 28 that connects the vacuum suction device 24 to the second housing 50, a first pressure passage 30 that connects the first pressure pump 42 to the second housing 50, and a second pressure passage 32 that connects the second pressure pump 52 to the second vacuum suction passage 28. The vacuum suction device 24 then sucks up the sediment D through the sediment suction pipe 14 and the first vacuum suction line 26 and transports it to the first housing 40. The sediment D in the first housing 40 is then pressurized by the first pressure pump 42 through the first pressure line 30 to the second housing 50, and the sediment D in the second housing 50 is pressurized by the second pressure pump 52 through the second pressure line 32 to the second vacuum suction line 28, where it is transported to the recovery tank 20. This dredging operation prevents pollution of the work water area and is advantageous for recovering sediment D from deep waters. In other words, by using the airflow generated by the vacuum suction device 24 to suck up the excavated sediment D from the sediment suction pipe 14, the sediment D can be recovered before it clouds the water at the bottom B of the dam reservoir W, thereby preventing pollution, and by transporting the water in two stages using the first pressure pump 42 and the second pressure pump 52, the sediment D can be recovered even from the lift from near the bottom B of the dam reservoir W, where the water is deep, to the recovery tank 20 on land. Furthermore, since the dredging work can prevent the water area at the bottom B of the dam reservoir W from becoming polluted, the dredging work can be carried out in conjunction with hydroelectric power generation without stopping the hydroelectric power generation by the dam reservoir W.

[0022] Furthermore, the second vacuum suction path 28 is connected to the first vacuum suction path 26 above the second housing 50, and the first vacuum suction path 26 from the connection point of the second vacuum suction path 28 to the vacuum suction device 24 also serves as the second vacuum suction path 28. This means that the first vacuum suction path 26 can connect the first housing 40 and the vacuum suction device 24 without going through the second housing 50, which is advantageous in increasing the suction force of the vacuum suction device 24. In addition, the height from the underwater bottom B of the dam reservoir W to the lower end of the first housing 40, the height from the lower end of the first housing 40 to the lower end of the second housing 50, and the height from the lower end of the second housing 50 to the connection position of the first vacuum suction path 26 of the recovery tank 20 are each set to 6m to 9m, which is advantageous in increasing the lift from the underwater bottom B while suppressing a decrease in the conveying force of the first pressure pump 42 and the second pressure pump 52. Furthermore, since the first housing 40 is provided with a first air supply pipe 44 for supplying air to the inside of the first housing 40, and the second housing 50 is provided with a second air supply pipe 54 for supplying air to the inside of the second housing 50, the pressure on the vacuum suction paths 26, 28 and the pressure transport paths 30, 32 can be adjusted, which is advantageous in increasing the transport force of the deposited sediment D.

[0023] (Second embodiment) In the first embodiment of the dredging apparatus 10A, the second vacuum suction passage 28 was connected to the first vacuum suction passage 26 above the second housing 50, whereas in the second embodiment of the dredging apparatus 10B, the second vacuum suction passage is connected to the second housing. In the following description of the embodiment, the same parts and members as those in the first embodiment will be denoted by the same reference numerals, and the description thereof will be omitted, and the description will focus on the parts that are different from the first embodiment.

[0024] As shown in FIG. 3, the first vacuum suction path 66A is a suction path formed by a vacuum suction pipe that connects the vacuum suction device 24 and the first housing 40. In this embodiment, the second housing 50 is disposed midway along the first vacuum suction path 66 A. Therefore, the first vacuum suction path 66 A is configured to include the second housing 50. The second vacuum suction path 28 is a suction path formed by a vacuum suction pipe that connects the vacuum suction device 24 and the second housing 50. The first vacuum suction path 66A from the second housing 50 to the vacuum suction device 24 also serves as the second vacuum suction path . A recovery tank 20 and a filter 22 are interposed in the middle of the first vacuum suction path 66A, which also serves as the second vacuum suction path . The flow of dredging work and the lifting height by the dredging apparatus 10B of this embodiment are the same as those of the first embodiment.

[0025] In this way, the second embodiment provides the same effects as the first embodiment. Furthermore, since the second housing 40 is interposed in the middle of the first vacuum suction path 66 so that the first vacuum suction path 66 includes the second housing 50, the dredging device 10B can be simply configured and is advantageous in terms of reducing costs. Therefore, it is possible to prevent the first vacuum suction path 66, the second pressure delivery path 32, and the second vacuum suction path 28 from merging in the vicinity above the second housing 50, and to prevent the vacuum suction pipes and pressure delivery pipes that form each path from becoming tangled.

[0026] (Third embodiment) The dredging apparatus 10B of the second embodiment is configured with a first relay pump unit and a second relay pump unit, whereas the dredging apparatus 10C of the third embodiment is different in that it is further configured with a third relay pump unit. As shown in FIG. 4, the dredging device 10C further includes a third relay pump unit 70 and a third pressure-transport line 72.

[0027] The third relay pump unit 70 is configured to include a third housing 80 , a third pressure pump 82 , a third air supply pipe 84 , and a vacuum gauge 86 . The third housing 80 is rectangular parallelepiped-shaped and watertight, and is disposed between the first housing 40 and the second housing 50. The second housing 50 and the third housing 80 of this embodiment are disposed underwater in the dam reservoir W, and may be suspended by a gate-type facility similar to the first housing 40, or may be supported by another lifting device. The second housing 50 and the third housing 80 may also be disposed on land. The third pressure pump 82 is disposed inside the third housing 80, and pressure-feeds the sediment D inside the third housing 80 upward through a third pressure path 72, which will be described later. The third air supply pipe 84 is provided in the third housing 80 and supplies air to the inside of the third housing 80 . Specifically, in this embodiment, the third air intake pipe 84 has one end attached to the top surface of the third housing 80 and the other end extending upward from the third housing 80 positioned above the water, so as to be able to take in air. The third air supply pipe 84 is provided with a valve (not shown), and by controlling the opening and closing of this valve, the pressure to the first vacuum suction path 66 and the third pressure feed path 72 can be adjusted, thereby increasing the transport force of the deposited sediment D from the third housing 80 to the second housing 50. The vacuum gauge 86 is an instrument that measures the pressure (negative pressure) inside the first housing 40.

[0028] As shown in FIG. 4, the first vacuum suction path 66B is a suction path formed by a vacuum suction pipe that connects the vacuum suction device 24 and the first housing 40. In this embodiment, the second housing 50 and the third housing 80 are interposed in the middle of the first vacuum suction path 66B. Therefore, the first vacuum suction path 66B is configured to include the second housing 50 and the third housing 80. As in the second embodiment, the second vacuum suction path 28 is a suction path formed by a vacuum suction pipe connecting the vacuum suction device 24 and the second housing 50, and the first vacuum suction path 66B from the second housing 50 to the vacuum suction device 24 also serves as the second vacuum suction path 28. A recovery tank 20 and a filter 22 are interposed in the middle of the first vacuum suction path 66B, which also serves as the second vacuum suction path .

[0029] The third pressure-feeding path 72 is a pressure-feeding path formed by a pressure-feeding pipe connecting the third pressure-feeding pump 82 and the second housing 50, and pumps the sediment D inside the third housing 80 to the second housing 50. As in the second embodiment, the first pressure-transfer path 30 is a pressure-transfer path formed by a pressure-transfer pipe connecting the first pressure-transfer pump 42 and the second housing 50, and pressurizes the deposited sediment D in the first housing 40 to the second housing 50. In this embodiment, the first pressure-feeding path 30 connects the first pressure-feeding pump 42 and the second housing 50 via the third pressure-feeding pump 82 and the third pressure-feeding path 72, thereby pressure-feeding the sediment D in the first housing 40 to the second housing 50.

[0030] Next, the transportation and lifting range of the sediment D from the underwater bottom B of the dam reservoir W to the recovery tank 20 by the dredging device 10C of this embodiment will be described. In this embodiment, the height h5 from the bottom B of the dam reservoir W to the lower end of the first housing 40, the height h6 from the lower end of the first housing 40 to the lower end of the third housing 80, the height h7 from the lower end of the third housing 80 to the lower end of the second housing 50, and the height h8 from the lower end of the second housing 50 to the connection position of the first vacuum suction path 66B of the recovery tank 20 are each set to 6m to 9m. Therefore, in this embodiment, the distance from the bottom B of the dam reservoir W to the recovery tank 20 is divided into sections of 6 to 9 m, and the sediment D is transported using a vacuum suction device 24 and three pressure pumps 42, 52, and 82, making it easy to transport the sediment D to the recovery tank 20. That is, the dredging device 10C of this embodiment is suitable for a case where the height H2 from the bottom B of the dam reservoir W to the recovery tank 20 is a lift of 24 m to 36 m.

[0031] Next, the flow of dredging work by the dredging apparatus 10C of this embodiment will be described. By connecting vacuum suction pipes and pressure feed pipes to the first relay pump unit 12, the second relay pump unit 14, and the third relay pump unit 70, a first vacuum suction path 66B, a second vacuum suction path 28, a first pressure feed path 30, a second pressure feed path 32, and a third pressure feed path 72 are formed. The sediment D sucked from the sediment suction pipe 14 by the vacuum suction device 24 is transported to the inside of the first housing 40 and collected. Next, the sediment D collected inside the first housing 40 is pumped by the first pressure pump 42 and transported through the first pressure path 30 to the inside of the third housing 80, where the sediment D is collected. When the sediment D is transported to the third housing 80, the sediment D collected inside the third housing 80 is pressurized by the third pressure pump 82, and transported through the third pressure path 72 to the inside of the second housing 50, where the sediment D is collected. When the sediment D is transported to the second housing 50, the sediment D recovered inside the second housing 50 is pumped by the second pressure pump 52 and transported through the second pressure path 32 toward the second vacuum suction path 28, where it merges with the second vacuum suction path 28. The merged sediment D is then transported by the vacuum suction device 24 and the second pressure pump 52 through the second vacuum suction path 28 (first vacuum suction path 66B) to the recovery tank 20. Meanwhile, a portion of the sediment D recovered inside the first housing 40 by the vacuum suction device 24 is transported to the recovery tank 20 through the first vacuum suction path 66B and the second vacuum suction path 32. That is, the sediment D sucked and transported by the vacuum suction device 24 and the sediment D pressurized by the first pressure pump 42, the second pressure pump 52, and the third pressure pump 82 join together at the connection point between the second pressure path 32 and the second vacuum suction path 28 and are collected in the collection tank 20. The sediment D collected in the collection tank 20 is then discharged to the collected sediment treatment facility 36, where it is separated into solids and water and subjected to a predetermined treatment.

[0032] In this way, the third embodiment provides the same effects as the first embodiment. In addition, a third housing 80 equipped with a third pressure pump 82 is placed between the first housing 40 and the second housing 50, and the sediment D in the first housing 40 is pressure-fed to the third housing 80, and then the sediment D in the third housing 80 is pressure-fed to the second housing 50. This is advantageous in increasing the lift from the bottom B of the water while maintaining the transport force of the sediment. In addition, the height from the underwater bottom B to the lower end of the first housing 40, the height from the lower end of the first housing 40 to the lower end of the third housing 80, the height from the lower end of the third housing 80 to the lower end of the second housing 50, and the height from the lower end of the second housing 50 to the connection position of the first vacuum suction path 66B of the recovery tank 20 are each set to 6m to 9m, which is advantageous in increasing the lift from the underwater bottom B while suppressing a decrease in the conveying force of the first pressure pump 32, the second pressure pump 42, and the third pressure pump 82. Furthermore, the first housing 40 is provided with a first air supply pipe 44 for supplying air to the inside of the first housing 40, the second housing 50 is provided with a second air supply pipe 54 for supplying air to the inside of the second housing 50, and the third housing 80 is provided with a third air supply pipe 84 for supplying air to the inside of the third housing 80, so that the pressure to the vacuum suction path and the pressure transport path can be adjusted, which is advantageous in increasing the transport force of the deposited sediment D.

[0033] In the third embodiment described above, one third relay pump unit 80 is disposed between the first relay pump unit 12 and the second relay pump unit 14, but a plurality of third relay pump units may be disposed. In this case, the vertical height (head) between the housings is preferably set to 6 m to 9 m. This is advantageous in further increasing the lift height from the bottom B of the water while maintaining the transport force of the sediment D.

[0034] Furthermore, in the above embodiment, the second pressure feed path 32 is configured to merge with the first vacuum suction path 26 (66A, 66B) and then connected to the collection tank 20, but the second pressure feed path and the second vacuum suction path may be configured to be connected separately to the collection tank 20. However, if the second pressure feed path 32 is configured to merge with the first vacuum suction path 66B as in this embodiment, it is possible to avoid complex arrangement of various piping and reduce costs. Furthermore, in the above embodiment, a single vacuum suction device 24 is provided, but a configuration may also be adopted in which multiple vacuum suction devices 24 are provided. However, because the vacuum suction device 24 is expensive, it is more cost-effective to provide multiple relay pump units each equipped with a pressure pump, as in this embodiment, and transport the sediment at the desired head. [Explanation of symbols]

[0035] 10A, 10B, 10C Dredging Equipment 12 First relay pump unit 14 Sediment suction pipe 16 Auger suction machine 18 Second relay pump unit 20 Recovery Tank 22 filters 24 Vacuum suction device 26, 66A, 66B 1st vacuum suction path 28 Second vacuum suction path 30 First pressure line 32 Second pressure line 34 Transfer pump 36. Collected soil and sand treatment equipment 40 First cabinet 42 No. 1 pressure pump 44 No. 1 air intake pipe 46 Vacuum Gauge 50 Second cabinet 52 Second pressure pump 54 Second air intake pipe 58 Vacuum Gauge 70 Third relay pump unit 72 Third pressure line 80 3rd cabinet 82 Third pressure pump 84 Third air intake pipe 86 Vacuum Gauge 90 barges 92 Gate type equipment

Claims

1. A dredging device for recovering sediment deposited on the bottom of the water, a first housing disposed underwater; a first pressure pump disposed inside the first housing; a sediment suction pipe provided in the first housing, the tip of which is disposed at the bottom of the water; a second housing disposed above the first housing; a second pressure pump disposed inside the second housing; and a vacuum suction device disposed on the water; a first vacuum suction path connecting the vacuum suction device and the first housing; a second vacuum suction path connecting the vacuum suction device and the second housing; a first pressure-feeding line connecting the first pressure-feeding pump and the second housing and pressure-feeding the sediment in the first housing to the second housing; a second pressure-feeding path that connects the second pressure-feeding pump and the second vacuum suction path and pressure-feeds the sediment in the second housing to the second vacuum suction path; A dredging device comprising:

2. The vacuum suction device is single, the second vacuum suction path is connected to the first vacuum suction path above the second housing; The first vacuum suction path from the connection point of the second vacuum suction path to the vacuum suction device also serves as the second vacuum suction path.

2. The dredging apparatus according to claim 1.

3. The vacuum suction device is single, the second housing is interposed in the middle of the first vacuum suction path, the first vacuum suction path is configured to include the second housing, the first vacuum suction path from the second housing to the vacuum suction device also serves as the second vacuum suction path; 2. The dredging apparatus according to claim 1.

4. The vacuum suction device is single, At least one third housing is disposed between the first housing and the second housing; a third pressure pump disposed inside the third housing; and a third pressure-transfer line connecting the third pressure-transfer pump and the second housing and pumping the sediment in the third housing to the second housing, the second housing and the third housing are interposed in the middle of the first vacuum suction path, the first vacuum suction path is configured to include the second housing and the third housing, the first pressure-feeding path connects the first pressure-feeding pump and the second housing via the third pressure-feeding pump and the third pressure-feeding path, and pumps the sediment in the first housing to the second housing; the first vacuum suction path from the second housing to the vacuum suction device also serves as the second vacuum suction path; 2. The dredging apparatus according to claim 1.

5. a recovery tank disposed on the water and interposed in the middle of the first vacuum suction path, for recovering sediment; The height from the bottom of the water to the lower end of the first housing, the height from the lower end of the first housing to the lower end of the second housing, and the height from the lower end of the second housing to the connection position of the first vacuum suction path of the recovery tank are each 6 m to 9 m. The dredging device according to any one of claims 1 to 3.

6. a first air supply pipe provided in the first housing and supplying air to an inside of the first housing; a second air supply pipe provided in the second housing and supplying air to the inside of the second housing, The dredging device according to any one of claims 1 to 3.

7. a recovery tank disposed on the water and interposed in the middle of the first vacuum suction path, for recovering sediment; The height from the bottom of the water to the lower end of the first housing, the height from the lower end of the first housing to the lower end of the third housing, the height from the lower end of the third housing to the lower end of the second housing, and the height from the lower end of the second housing to the connection position of the first vacuum suction path of the recovery tank are each 6 m to 9 m.

5. The dredging apparatus according to claim 4.

8. a first air supply pipe provided in the first housing and supplying air to an inside of the first housing; a second air supply pipe provided in the second housing and supplying air to the inside of the second housing; The dredging device according to claim 4, further comprising a third air supply pipe provided in the third housing and supplying air to the inside of the third housing.

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