JP6430838B2 - Suction spear device and suction spear method - Google Patents

Description

  The present invention relates to a suction rod apparatus and a suction rod method for performing a suction rod using a grab bucket.

  In Patent Document 1, the push plate is moved from the other side of the sediment storage chamber to the one side in a state where the pair of shells are closed so as to confine the sand caught between the pair of shells in the sediment storage chamber in front of the push plate. Disclosed is a grab bucket type earthing device in which it is not necessary to lift the grab bucket to the surface of the water for unloading by forcibly pumping the earth and sand in the earth and sand storage chamber into the transport pipe by a pushing plate. (Claim 1, FIG. 15).

  In Patent Document 2, a submersible pump is provided in one of a pair of shells, a pumping pipe is connected to the other, and water in the water sucked and pressurized by the submersible pump is sealed in a grab bucket closed from its discharge port. Inject into the storage chamber, stir and entrain the porridge in the pair of shells with the injected pressurized water, and pump it together with the injected pressurized water to the earthing pipe. The grab bucket type earthing device provided on the outside of the back surface of one shell facing the doorway for grabbing the soot is disclosed so as not to inhale the foreign material (Claim 1, FIG. 1).

  In Patent Document 3, the bottom sediment is excavated with a grab bucket, and then the water is blown into the grab bucket with the grab bucket closed to stir the sediment, and the stirred sediment is put on the water with a sand pump inside the grab bucket. Disclosed is a dredge method that repeats conveyance (claim 3).

Japanese Patent No.4944541 Japanese Patent No. 5171446 Japanese Unexamined Patent Publication No. 2005-30135

  In response to the problem that terrestrial pollutants flow into lakes, rivers, seas, and other water bodies due to rain, etc., and accumulate at high concentrations in the surface sediments of water bodies, thin sediments such as lakes, rivers, etc. It has been proposed to remove pollutants by performing dredging. In this dredging, it is necessary to take measures to prevent diffusion because disturbing the bottom sediment may diffuse the pollutant and expand the contamination range. For this reason, it is conceivable to apply the apparatuses and methods of Patent Documents 1 to 3 in order to prevent diffusion of pollutants while removing a thin layer of sediment containing a high concentration of pollutants. There is a problem.

  According to the grab bucket type earthing device of Patent Document 1, the sand in the earth and sand storage chamber is pushed in by rotating the pushing plate from the other side to the one side with the pair of shells closed. However, depending on the nature of the earth and sand, there is a risk that the efficiency of the dredging may be reduced because the earth and sand cannot be transported sufficiently due to the rotation of the pushing plate in the earth and sand storage chamber (grab bucket). In addition, when an obstacle such as a relatively large piece of wood or stone is mixed in the grab bucket, the driving of the pushing plate may be hindered. In addition, since the pushing plate is driven in the earth and sand storage chamber, if the driving portion fails, it takes time to repair and return.

  Further, according to the grab bucket type earthing device of Patent Document 2, an underwater pump is connected to one of the pair of shells, and a earthing pipe is connected to the other, and the water in the water sucked and pressurized by the underwater pump is discharged. It is injected from the outlet into the enclosed storage chamber in the grab bucket, and the soot in the pair of shells is stirred and entrained by the injected pressurized water, and is pumped together with the injected pressurized water to the earthing pipe. The soot is moved by the pressurized pressurized water that is sucked and pressurized by the submersible pump and injected into the sealed housing chamber, so that it may be difficult to obtain a sufficient pumping force, which may reduce the efficiency of the soot. There is.

  Moreover, according to the dredging method of Patent Document 3, the gravel bucket is closed and water is spouted into the grab bucket to stir the drowned earth and sand, and the agitated earth and sand is conveyed onto the water by a sand pump inside the grab bucket. However, since it is transported by a sand pump after the stirring is completed, it takes time and the efficiency of the soot may be reduced.

  In view of the problems of the prior art as described above, the present invention, for example, when dredging bottom sediment such as lakes and rivers, suction that can efficiently perform dredging while preventing diffusion of the bottom sediment. It is an object to provide a dredge device and a suction dredge method.

  A suction dredge apparatus for achieving the above object is connected to a grab bucket having a pair of shells that can be opened and closed for dredging, a suction means connected to the suction port of the grab bucket, and a stirring port of the grab bucket. A stirring means, a water supply port provided in the grab bucket, and a cross-sectional area in the flow direction from the water supply port to the suction port in the grab bucket with the pair of shells closed. A partition member, and when the shell is closed in water, the dredging target earth and sand are held in the grab bucket together with water in the vicinity thereof, and the stirring means is used to mix the earth and sand in the grab bucket. The mixture of earth and sand by the stirring is sucked by the suction means and discharged to the outside, and from the water supply port according to the suction Part of water to continue the suction and discharge by stirring with the suction means by the stirring means while being fed.

  According to this suction dredge device, while the pair of shells are closed in the water and the dredged soil and the water nearby are held in the grab bucket, the sand and water are stirred by the stirring means in the grab bucket. The mixture of earth and sand and water can be sucked by the suction means and discharged to the outside. In this way, stirring for mixing slurry and water to make a slurry and suction / discharge of the mixture are performed by separate means, suction is performed while stirring, and suction of the slurry mixture of soil and water is sucked.・ Since it can be discharged smoothly and quickly, dredging can be carried out efficiently while preventing diffusion of earth and sand. In addition, when the mixture is sucked / discharged in the grab bucket, since the water is supplied from the outside through the water supply port, the stirring by the stirring means and the suction / discharge by the suction means are continued. The discharge can be performed reliably. Further, by adjusting the flow direction cross-sectional area from the water supply port to the suction port in the grab bucket with the partition member, the flow velocity in the flow direction can be adjusted, and the flow can be guided to the vicinity of the bottom of the grab bucket where sediment is accumulated. Therefore, efficient stirring and suction can be performed, which can contribute to the efficiency of the soot. Furthermore, since there is no drive part for agitation / suction in the grab bucket, even if obstacles are included in the earth and sand, there is no failure.

  It is preferable that the suction pad apparatus includes a sensor that detects the concentration of the mixture sucked by the suction unit, and the suction unit is controlled based on the concentration detected by the sensor. The concentration of the dredged soil and water mixture can be monitored in real time by a sensor, and the progress of suction can be grasped in real time based on the detected concentration, so the suction means is controlled in real time based on the detected concentration be able to.

  For example, the suction means is controlled so that the operation is stopped when the concentration detected by the sensor becomes a predetermined value or less, so that the soil that has been drowned at the time when the concentration is reduced to a predetermined value or less is controlled. Since it can be determined in real time that the suction / discharge is completed, the operation of the suction means can be stopped immediately, the suction of excess water can be prevented, and the efficiency of the dredging can be contributed.

  Further, it is preferable that an obstacle removing unit is provided on the upstream side of the suction port in order to prevent the obstacle in the grab bucket from being sucked by the suction means. Thereby, even if obstacles such as wood fragments and stones are included in the dredged earth and sand, it can be prevented from being sucked to the suction means and causing trouble.

  Further, it is preferable that the suction port is provided in one of the pair of shells, and the water supply port is provided in the other of the pair of shells. In addition, it is preferable that the partition member which adjusts the flow direction cross-sectional area from a water supply port to a suction port is provided between one side and the other of a pair of shells.

  The stirring means includes a stirring pump, a stirring suction pipe that passes the earth and sand from the grab bucket, and a stirring discharge pipe that passes the earth and sand toward the grab bucket; The grab bucket has a stirring suction port to which the stirring suction pipe is connected as the stirring port and a stirring discharge port to which the stirring discharge pipe is connected, and the stirring pump is disposed in the grab bucket. The water and the earth and sand are sucked through the stirring suction port and the stirring suction pipe, and the water flow in the grab bucket is returned to the grab bucket through the stirring discharge pipe and the stirring discharge port. Stirring can be performed.

  In the suction dredge apparatus, the grab bucket is configured such that when the pair of shells open and close, the trajectory of the blade edge is substantially horizontal and horizontal thin layer excavation is possible, so that a lake, a river, etc. In this case, it is possible to remove a thin layer of sediment containing a high concentration of contaminants, and to prevent diffusion of the contaminants while removing the contaminants from the surface layer of the sediment.

A suction dredging method for achieving the above object is a first step of holding a pair of openable and closable shells provided in a grab bucket in the water so that the dredged sediment is held in the grab bucket together with water in the vicinity thereof. And stirring the earth and sand and the water in the grab bucket by the stirring means, sucking the mixture of the sand and water by the stirring from the suction port by the suction means and discharging to the outside, and according to the suction and a second step of continuing with external water is supplied from the sheet Mizuguchi and stirred by the stirring means and a suction and discharge by the suction means, and from the water supply port within the grab bucket to the suction port The flow direction sectional area is adjusted by the partition member to adjust the flow velocity in the flow direction.

  According to this suction dredging method, the pair of shells close in water to hold the dredged sediment and its nearby water in the grab bucket, and then the sand and water are stirred by the stirring means in the grab bucket. However, the mixture of earth and sand and water can be sucked by the suction means and discharged to the outside. In this way, stirring for mixing slurry and water to make a slurry and suction / discharge of the mixture are performed by separate means, suction is performed while stirring, and suction of the slurry mixture of soil and water is sucked.・ Since it can be discharged smoothly and quickly, dredging can be carried out efficiently while preventing diffusion of earth and sand. In addition, when the mixture is sucked / discharged in the grab bucket, the water is supplied from the outside through the water supply port and the stirring by the stirring means and the suction / discharge by the suction means are continued, so that the mixture can be sucked / discharged quickly and smoothly. Can be performed reliably. Further, by adjusting the flow direction cross-sectional area from the water supply port to the suction port in the grab bucket with the partition member, the flow velocity in the flow direction can be adjusted, and the flow can be guided to the vicinity of the bottom of the grab bucket where sediment is accumulated. Therefore, efficient stirring and suction can be performed, which can contribute to the efficiency of the soot. Furthermore, since a driving part for agitation / suction is not required in the grab bucket, no trouble occurs even if the earth and sand contain obstacles.

  In the suction pad method, it is preferable that the concentration of the mixture sucked is detected by a sensor, and the suction means is controlled based on the concentration detected by the sensor. The concentration of the dredged soil and water mixture can be monitored in real time by a sensor, and the progress of suction can be grasped in real time based on the detected concentration, so the suction means is controlled in real time based on the detected concentration be able to.

  For example, the suction means is controlled so that the operation is stopped when the concentration detected by the sensor becomes a predetermined value or less, so that the soil that has been drowned at the time when the concentration is reduced to a predetermined value or less is controlled. Since it can be determined in real time that the suction / discharge is completed, the operation of the suction means can be stopped immediately, the suction of excess water can be prevented, and the efficiency of the dredging can be contributed.

  Moreover, it is preferable to further have a step of pre-inspecting the moisture content of the dredged soil.

  Further, when the water content ratio of the soil to be dredged is equal to or greater than a predetermined value, it is preferable that in the second step, the stirring by the stirring means and the suction / discharge by the suction means are started almost simultaneously. When the moisture content of the soil to be dredged is large, it is not necessary to start stirring only in advance, and this stirring can be omitted, which can contribute to the efficiency of dredging.

  According to the suction dredge apparatus and the suction dredge method of the present invention, for example, when dredging bottom sediment such as lakes and rivers, dredging can be performed efficiently while preventing diffusion of the bottom sediment.

It is a front view which shows roughly the suction spear apparatus by this embodiment. It is a top view of the grab bucket of FIG. It is the schematic for demonstrating the process (a)-(d) of the suction / discharge of earth and sand by the suction dredge apparatus 10 of FIG. 1, FIG. 2, and stirring. It is the schematic for demonstrating excavation operation (a)-(e) of the earth and sand in the water by the suction dredge apparatus 10 of FIGS. 1-3. It is a flowchart for demonstrating the sputum suction process S01-S06 by the suction sputum apparatus 10 of FIGS. 1-3.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a front view schematically showing a suction rod apparatus according to the present embodiment. FIG. 2 is a plan view of the grab bucket of FIG. 1 and 2, the grab bucket is shown with a pair of shells closed.

  As shown in FIG. 1, the suction rod apparatus 10 according to the present embodiment includes a grab bucket 20 composed of a pair of left and right shells 11 and 12 that can be opened and closed for the rod, and is positioned above the shells 11 and 12. A support 13 that is suspended by a suspension wire W1, and a pair of left and right arms that are pivotally supported by a support shaft 16 on the support 13 and supported by support shafts 18 and 19 so that the shells 11 and 12 can be rotated. 14 and 15 and a connecting shaft 21 that rotatably connects the shells 11 and 12.

  The grab bucket 20 is configured to open and close the pair of left and right shells 11 and 12 about the support shafts 18 and 19 by moving the connecting shaft 21 up and down with an operation wire W2. The grab bucket 20 is adapted to bend while the support 13 is suspended by a suspension wire W1 with a crane or the like.

  As shown in FIGS. 1 and 2, the grab bucket 20 is configured to have a box shape with the shells 11 and 12 being closed, and the blades 11 a and 11 b are opened and closed while the shells 11 and 12 are opened and closed. The soil to be dredged is excavated from 12a. As shown in FIG. 2, the grab bucket 20 is configured to extend in the axial direction of the connecting shaft 21 positioned at the rotation center of the shells 11 and 12, and the side plates 11 b and 12 b are positioned at the front end and the rear end. 11b, and top plates 11c and 12c located on the top surface with the shells 11 and 12 closed between the side plates 12b and 12b.

  During the opening and closing operation of the pair of shells 11 and 12 by raising and lowering the operation wire W2, the grab bucket 20 is configured so that the trajectories of the blade edges 11a and 12a of the pair of shells 11 and 12 are almost horizontal. It is possible to excavate soil at a predetermined depth from the bottom of the water, so that no excessive excavation amount is generated. Since the configuration of such a grab bucket is known, for example, from Japanese Patent Laid-Open No. 2012-17198, description thereof is omitted.

  1 further includes a suction device 30 that sucks a mixture (slurry) of earth and sand from the inside of the grab bucket 20 and discharges the mixture to the outside, and agitation that stirs the earth and sand in the grab bucket 20. Device 40.

  As shown in FIGS. 1 and 2, the suction device 30 includes a suction pump 31 disposed on the support 13, a suction port 32 provided on the upper surface plate 11 c of the shell 11, a suction pump 31 and a suction port 32. A flexible suction pipe 33 composed of a hose and the like, a drain pipe 34 for discharging the slurry sucked from the grab bucket 20 by the suction pump 31 to the outside, and a reverse flow of the slurry provided in the drain pipe 34 And a check valve 35 for preventing the above.

  1 and 2, the stirring device 40 includes a stirring pump 41 disposed on the support 13, a stirring suction port 42 provided in the upper surface plate 11c of the shell 11, a stirring pump 41, and a stirring suction. It comprises a flexible agitation suction pipe 43 comprising a hose for connecting the opening 42, a stirring discharge port 44 provided on the side of the shell 12, a hose for connecting the stirring pump 41 and the stirring discharge port 44, etc. A flexible agitation discharge pipe 45. The agitation pump 41 sucks water and earth and sand from the grab bucket 20 through the agitation suction port 42 and the agitation suction pipe 43, and returns the water to the grab bucket 20 through the agitation discharge pipe 45 and the agitation discharge port 44. Powerful water agitation can be performed in the grab bucket 20 while circulating.

  The upper surface plate 12c of the shell 12 is provided with water supply ports 50 at two locations so that water is supplied into the grab bucket 20 during drought. Further, in the grab bucket 20, as shown in FIG. 1, a plate-like partition member 51 is provided at the boundary between the shells 11 and 12 so as to protrude downward from the upper surface, and from the water supply port 50 in the grab bucket 20. The cross-sectional area in the flow direction to the suction port 32 is adjusted.

  As shown in FIGS. 1 and 2, an obstacle removing unit 52 is provided below the upper surface plate 11c in the grab bucket 20 so as to cover the entire lower surface of the upper surface plate 11c. As a result, the obstacle removing unit 52 is located below (upstream) the suction port 32 and the stirring suction port 42, so that obstacles such as wood fragments and stones contained in the dredged earth and sand are sucked into the suction pipe 33 and the stirring suction pipe 43. It is prevented from being sucked in. The obstacle removing unit 52 is configured in a plate shape, and can be configured from, for example, a wire mesh member or expanded metal. In the grab bucket 20, a plurality of L-shaped members 53 are provided on the partition plate 51 and the side plates so as to jump up and down in the paper surface of FIG. 2, and plate-like obstacle removal is performed so as to be placed on these L-shaped members 53. The portion 52 is disposed and fixed so as to maintain a predetermined clearance between the suction port 32 and the stirring suction port 42.

  A sensor 39 for detecting the concentration is provided on the inner surface of the suction tube 33 at a position close to the suction port 32, and the concentration of the slurry in the suction tube 33 is detected in real time in order to check the suction state. . The sensor 39 can be composed of a turbidimeter or a density meter, for example. The suction pump 31 is controlled in real time based on the concentration of the slurry detected by the sensor 39. For example, when the detected concentration falls below a predetermined value, the suction pump 31 is controlled in real time so that its operation is stopped. The agitation pump 41 is also controlled in the same manner as the suction pump 31.

  Next, with reference to FIGS. 3A to 3D, the suction / discharge of the slurry of the earth and sand and the agitation of the earth and sand by the suction pad 10 will be described. FIG. 3 is a schematic view of a grab bucket for explaining the steps (a) to (d) of the suction / discharge and the stirring / mixing of earth and sand by the suction dredge apparatus 10 of FIGS.

  First, when the pair of shells 11 and 12 of the suction dredge apparatus 10 are closed at the bottom of the water, the earth and sand D and the water W in the vicinity thereof are held in the grab bucket 20 as shown in FIG. In this state, when the operation of the agitation pump 41 is started in the grab bucket 20, the earth and sand D and the water W are flow-stirred and mixed. By this stirring, the mixture of earth and sand D and water W is slurried. Subsequently, when the operation of the suction pump 31 is started, the slurry (earth and sand slurry S) of the earth and sand D and the water W is sucked and discharged to the outside. Thereby, in the grab bucket 20, external water is taken in from the water supply port 50 in the shell 12, and water / sediment flows in the arrow direction a from the water supply port 50 toward the suction port 32 in the shell 11. By the partition member 51 protruding toward the bottom of the grab bucket 20 between the shells 11 and 12, the flow can be guided to the vicinity of the bottom of the grab bucket 20 where the earth and sand D is accumulated, and the cross-sectional area in the flow direction is adjusted to be small. As a result, the flow rate is maintained at a predetermined value or higher.

  Next, as shown in FIG. 3B, in the grab bucket 20, the water flow stirring by the stirring pump 41 is continuously performed, whereby the earth and sand slurry S is sucked by the suction pump 31 and discharged to the outside. The clay component adhering to the obstacle B such as a piece of wood or stone mixed in the earth and sand D is washed and separated. Along with this discharge, external water is supplied into the grab bucket 20 from the water supply port 50, while stirring the mixture (sediment slurry S) remaining in the grab bucket 20 and the water from the water supply port 50 with the stirring pump 41, The suction and discharge of the earth and sand slurry S by the suction pump 31 is continued.

  In addition, the obstacle B flows to the suction port 32 and the stirring suction port 42 side due to the water flow caused by the suction of the earth and sand slurry S, but the obstacle removing unit 52 is prevented from flowing to the suction port 32 and the stirring suction port 42 side. , Accumulated in the grab bucket 20. Thereby, even if the obstacle B is contained in the earth and sand D, it is possible to prevent the suction pipe 33, the suction pump 31, the stirring suction pipe 43, and the stirring pump 41 from causing a failure.

  As the agitation / suction proceeds, the earth / slurry slurry S is diluted with water. As shown in FIG. 3C, the concentration of the earth / slurry slurry S passing through the suction pipe 33 is reduced during the agitation / aspiration. Monitoring is constantly performed by the sensor 39, and when the concentration drops below a predetermined value, it is determined that stirring / suctioning has ended, and the suction pump 31 and the stirring pump 41 are stopped.

  As described above, the stirring, suction and discharge of the earth and sand D to be dredged is completed. As a result, as shown in FIG. 3D, only the obstacle W cleaned with the water W is contained in the grab bucket 20. Remains.

  Next, with reference to FIGS. 1-5, the wrinkle suction process by the suction pad apparatus 10 of FIGS. 1-3 is demonstrated. FIG. 4 is a schematic view for explaining excavation operations (a) to (e) of earth and sand in water by the suction dredge device 10 of FIGS. 1 to 3. FIG. 5 is a flowchart for explaining the sputum suction steps S01 to S09 performed by the suction spear device 10 of FIGS.

  First, a preliminary survey is carried out for dredged soil (S01). As a result, the moisture content, liquid limit, etc. of the soil to be dredged are confirmed by tests.

  Next, the grab bucket 20 is suspended by the support 13 of the suction rod apparatus 10 of FIGS. 1 to 3 being suspended by a crane (not shown) with a suspension wire W1, and above the ground G to be dredged by crane operation. (S02).

  Next, as shown in FIG. 4A, the pair of shells 11 and 12 of the grab bucket 20 are opened by raising and lowering the operation wire W2 of the suction rod apparatus 10 (S03).

  Next, the grab bucket 20 suspended by the suspension wire W1 is lowered from the water surface toward the dredged ground G, and is landed on the bottom G1 as shown in FIG. 4A (S04). Thereby, the blade edges 11a and 12a of the shells 11 and 12 are penetrated from the water bottom G1 to a predetermined depth.

  Subsequently, the earth and sand of the ground G is excavated by moving the pair of shells 11 and 12 of the grab bucket 20 in the closing direction as shown in FIGS. Finally, as shown in FIG. 4E, the shells 11 and 12 are closed to hold the earth and sand in the grab bucket 20 (S05). At this time, water in the vicinity thereof is also taken in and held in the grab bucket 20. During the operation of FIGS. 4A to 4E, the grab bucket 20 has the trajectories of the blades 11a and 12a of the shells 11 and 12 nearly horizontal, and therefore excavates soil having a predetermined depth from the bottom G1, Horizontal thin layer excavation can be performed.

  Next, as shown in FIGS. 3A to 3D, the agitation pump 41 of the suction dredge device 10 is operated in advance, and the earth and sand in the grab bucket 20 are agitated and mixed (S06). Then, the suction pump 31 is operated, and the earth and sand slurry S is sucked and discharged to the outside while stirring and mixing the earth and sand in the grab bucket 20 (S07).

  During the agitation and suction step S07, the concentration of the earth and sand slurry S in the grab bucket 20 is monitored in real time by the sensor 39. When the concentration is reduced below a predetermined value (S08), the suction of the earth and sand is completed. It is judged that the stirring pump 41 and the suction pump 31 are immediately stopped (S09). Thereby, the suction of excess water can be reduced.

  As described above, the suction rod for the dredging target ground G by the suction rod device 10 is completed, but when continuing the suction rod, the suction rod device 10 is lifted and moved to a predetermined position by a crane operation. Similar steps are repeated.

  In addition, the prior stirring in step S06 may be performed, for example, when the moisture content of the soil to be dredged obtained by the preliminary survey in step S01 is a predetermined value or less, and may be omitted if the water content is a predetermined value or more. . When the moisture content of the soil to be dredged is large, there is no need for prior stirring, so the preceding stirring step S06 can be omitted. With regard to the water content ratio of the earth and sand, for example, if the liquid limit of the earth and sand is LL, 2 × LL can be set as a judgment standard value (predetermined value), but is not limited to this, and other judgment standard values are used. It may be set.

  As described above, according to the suction dredge apparatus 10 according to the present embodiment, the pair of shells 11 and 12 are closed in the water so that the dredged sediment is excavated and held in the grab bucket 20 together with the water nearby. Then, in the grab bucket 20, water and earth and sand are mixed with water by stirring and mixing with the stirring device 40 and sucked by the suction device 30 and discharged to the outside. Since the suction of the mixture is performed with separate devices 30 and 40, suction is performed while stirring, and the slurry of the sand and water (sediment slurry S) can be sucked smoothly and quickly. It is possible to perform dredging efficiently while preventing diffusion of earth and sand. Further, when the earth and sand slurry S is sucked and discharged in the grab bucket 20, the stirring by the stirring device 40 and the suction and discharging by the suction device 30 are continued while water is being supplied from the outside through the water supply port 50, so that it is quick and smooth. It is possible to reliably suck and discharge the earth and sand slurry S.

  Further, by adjusting the flow direction cross-sectional area from the water supply port 50 to the suction port 32 in the grab bucket 20 to be small by the partition member 51, the flow velocity in the flow direction can be adjusted, and the vicinity of the bottom of the grab bucket 20 on which earth and sand are accumulated Since the flow can be guided to the flow, efficient stirring, mixing, and suction can be performed, contributing to the efficiency of the soot. Furthermore, since there is no drive part for agitation / suction in the grab bucket 20, even if an obstacle is included in the earth and sand, no failure occurs.

  Further, the grab bucket 20 can perform horizontal thin layer excavation so that the trajectories of the blade edges 11a and 12a become substantially horizontal when the pair of shells 11 and 12 are opened and closed. The thin layer of the sediment contained in the concentration can be removed, and the diffusion of the contaminant can be prevented while removing the contaminant from the surface layer of the sediment.

  As described above, the modes for carrying out the present invention have been described. However, the present invention is not limited to these, and various modifications can be made within the scope of the technical idea of the present invention. For example, two (or more) suction pumps or the like of the suction device 30 of FIGS. 1 and 2 may be provided to perform suction with two systems (or more systems). For example, two (or more) 40 agitation pumps may be provided and stirred in two systems (or more systems). A suction pump or a stirring pump may be installed on the upper surface plates 11c and 12c of the grab bucket 20.

  Further, the sensor 39 for detecting the concentration of the slurry may be provided in the grab bucket 20, for example, or may be provided in the stirring suction pipe 43 and the stirring discharge pipe 45 of the stirring device 40. The sensors 39 may be provided at a plurality of locations.

  Moreover, although the stirring apparatus 40 was comprised from the apparatus which carries out water flow stirring, circulating water, this invention is not limited to this, For example, you may comprise from the stirring apparatus by a mechanical stirrer or a high pressure jet.

  Further, the protruding length of the partition member 51 in the grab bucket 20 is appropriately set based on the desired cross-sectional area in the flow direction, the dimensions of the grab bucket 20, and the like.

  Further, a check valve may be provided at the water supply port 50, and when the suction pump 31 sucks earth and sand slurry, the check valve is opened so that an appropriate amount of water can be supplied.

  In the present specification, the mixture means a mixture of earth and sand excavated from the bottom of the water and water (water contained in the earth and sand and water taken into the grab bucket). It means a stable mixture of earth and sand and water.

  According to the present invention, when dredging sediment such as lakes and rivers, dredging can be performed efficiently while preventing diffusion of the sediment to the surroundings. Even if substances are accumulated at a high concentration, contaminants can be safely and efficiently removed while suppressing the influence on the surrounding environment.

DESCRIPTION OF SYMBOLS 10 Suction apparatus 11, 12 A pair of shell 11a, 12a Blade edge 11c, 12c Upper surface board 13 Support body 20 Grab bucket 30 Suction apparatus 31 Suction pump 32 Suction port 39 Sensor 40 Stirrer 41 Stirrer pump 42 Stirrer inlet 44 Stirrer outlet 50 Water supply port 51 Partition member 52 Obstacle removal part B Obstacle D Earth and sand G Ground G1 Water bottom S Earth and sand slurry

Claims (8)

A grab bucket having a pair of shells openable and closable for dredging,
Suction means connected to the suction port of the grab bucket;
Stirring means connected to the stirring port of the grab bucket;
A water inlet provided in the grab bucket;
A partition member provided so as to adjust a cross-sectional area in the flow direction from the water supply port to the suction port in the grab bucket in a state where the pair of shells are closed,
With the shell closed in water, the dredged soil is held in the grab bucket together with the water in the vicinity thereof, the sand and the water are stirred by the stirring means in the grab bucket, and the sand by the stirring A mixture of water and water is sucked by the suction means and discharged to the outside, and stirring by the stirring means and suction / discharge by the suction means are performed while external water is supplied from the water supply port according to the suction. Suction dredge device to continue. A sensor for detecting the concentration of the mixture sucked by the suction means;
The suction rod apparatus according to claim 1, wherein the suction means is controlled based on a concentration detected by the sensor.   3. The suction rod apparatus according to claim 1, further comprising an obstacle removing unit on an upstream side of the suction port in order to prevent an obstacle in the grab bucket from being sucked by the suction unit.   The suction rod apparatus according to any one of claims 1 to 3, wherein the suction port is provided in one of the pair of shells, and the water supply port is provided in the other of the pair of shells. A first step of holding a pair of openable and closable shells provided in the grab bucket in the grab bucket together with water in the vicinity thereof by closing the pair of openable and closable shells in the water;
Stirred by the stirring means the water and the soil within the grab bucket, with discharged to the outside, air is sucked from a suction opening by a suction means a mixture of soil and water by the stirring, the sheet according to the suction Mizuguchi A second step of continuing stirring by the stirring means and suction / discharge by the suction means while external water is being supplied from,
A suction rod method in which a flow direction cross-sectional area from the water supply port to the suction port in the grab bucket is adjusted by a partition member to adjust a flow rate in the flow direction.
A concentration of the sucked mixture is detected by a sensor;
The suction rod method according to claim 5, wherein the suction means is controlled based on the concentration detected by the sensor.   The suction dredging method according to claim 5 or 6, further comprising a step of preliminarily examining a water content ratio of the dredged soil.   8. The method according to claim 5, wherein, when the water content ratio of the soil to be dredged is a predetermined value or more, in the second step, stirring by the stirring unit and suction / discharge by the suction unit are started almost simultaneously. The suction sputum method described in 1.