Mechanical and hydraulic combined river channel sludge dredging method and equipment thereof

Abstract

The application relates to the technical field of river dredging equipment, and discloses a mechanical and hydraulic combined river sludge dredging method and equipment, which comprises two supports, an electric sliding rail is arranged between the two supports, a sliding seat is slidably connected to the outer portion of the electric sliding rail, a hydraulic rod is fixedly connected to the lower surface of the sliding seat, an auxiliary rod is flange-connected to the output end of the hydraulic rod, a transfer pipe is flange-connected to the output end of the auxiliary rod, a cutting frame is flange-connected to the input end of the transfer pipe, a waterproof motor is fixedly connected to the upper surface of the cutting frame, the output end of the waterproof motor penetrates through the cutting frame and is fixedly connected with a cutting head one. The mute assembly and the flexible skirt at the bottom form a closed physical operation cover, the cutting area is completely isolated from the external river water; meanwhile, the active hydraulic curtain formed by the nozzle of the blocking ring, in combination with the whole-closed conveying of the conveying hose, fundamentally eliminates the problems of silt diffusion and turbidity of the water body.

Description

Technical Field

[0001] This invention relates to the field of river dredging equipment technology, specifically to a mechanical and hydraulic combined method and equipment for dredging river silt. Background Technology

[0002] Dredging of river channels is a routine and crucial task in water conservancy projects and environmental management. It plays an irreplaceable role in maintaining the flood control capacity of rivers, ensuring smooth navigation, improving water quality, and restoring the ecological functions of aquatic areas. Currently, mainstream river dredging operations mostly employ mechanical or hydraulic methods, such as cutter suction dredging equipment and grab bucket dredging equipment, which are widely used in projects.

[0003] However, existing dredging technologies generally have significant negative environmental impacts during implementation. Traditional open-field operations, where cutting or grabbing components directly agitate riverbed sediment, inevitably cause the resuspension and widespread diffusion of large amounts of silt and deposited pollutants, leading to rapid turbidity in the work area and downstream waters. This turbidity not only severely impacts the photosynthesis of aquatic plants and the normal survival of fish and shrimp, disrupting the original ecological balance of the water, but also releases harmful substances deposited in the silt back into the water, causing secondary pollution. Furthermore, the enormous mechanical noise and vibration generated by dredging equipment during operation also disturb the surrounding acoustic environment and underwater ecosystems. Simultaneously, during dredging, the cutting components come into direct contact with the complex silt layer and are frequently impacted by hard debris such as rocks and garbage. This not only drastically accelerates cutter wear, reducing equipment lifespan, but may even damage the equipment, affecting construction efficiency and safety. Therefore, how to efficiently complete dredging tasks while minimizing mud diffusion and noise pollution during operations, and improving the adaptability and reliability of equipment to complex working conditions, is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a mechanical and hydraulic combined method and equipment for dredging river silt, which solves the problems of serious water pollution and ecological damage caused by the large-scale diffusion of silt in traditional river dredging operations, and the vulnerability of cutting parts to impact damage due to direct contact with hard objects on the riverbed.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a mechanical and hydraulic combined river silt dredging device, comprising two supports, an electric slide rail installed between the two supports, a sliding base slidably connected to the outside of the electric slide rail, a hydraulic rod fixedly connected to the lower surface of the sliding base, an auxiliary rod connected to the output flange of the hydraulic rod, a transfer pipe connected to the output flange of the auxiliary rod, a cutting frame connected to the input flange of the transfer pipe, a waterproof motor fixedly connected to the upper surface of the cutting frame, the output end of the waterproof motor passing through the cutting frame and fixedly connected to a cutting head one, a gear one fixedly connected to the output end of the waterproof motor, the gear one rotatably connected inside the cutting frame, multiple gear twos rotatably connected inside the cutting frame, the gear twos meshing with the gear one through a gear three, the gear three rotatably connected inside the cutting frame, a cutting head two fixedly connected to the lower surface of the gear twos, the cutting head two located outside the cutting frame, multiple cutting heads two arranged in a circular array around the cutting head one, and a noise-reducing component provided outside the auxiliary rod.

[0006] Preferably, the noise reduction assembly includes a sliding groove formed on the outer surface of the auxiliary rod, and a noise reduction cover is slidably connected inside the sliding groove. The noise reduction assembly also includes a noise reduction cover, which is fixedly connected to the side surface of the cutting frame and is located inside the noise reduction cover.

[0007] Preferably, a groove is formed at the lower end of the inner surface of the soundproof cover, and two fixing rings are slidably connected to the two ends of the groove. Multiple telescopic rods and multiple springs are fixedly connected between the two fixing rings. The springs are sleeved on the outside of the telescopic rods, near the input end of the soundproof cover. A filter screen is fixedly connected to the inner surface of the fixing rings.

[0008] Preferably, a damping ring is fixedly connected to the lower end of the outer surface of the soundproof cover. The inside of the damping ring is hollow, and the output end of the damping ring is connected to the outside. The output end of the damping ring is connected to a nozzle.

[0009] Preferably, the output end of the transfer pipe is connected to a conveying hose, and the output end of the conveying hose passes through the soundproof cover and is connected to the outside.

[0010] Preferably, a guide cover is fixedly connected inside the soundproof cover, and a disturbance plate is fixedly connected to the lower surface of the guide cover.

[0011] Preferably, the top of the soundproof enclosure has multiple overflow holes, which pass through the soundproof enclosure.

[0012] Preferably, a flexible skirt is fixedly connected to the lower surface of the soundproof cover, and the spray direction of the nozzle is downward toward the outer side of the flexible skirt.

[0013] Preferably, a plurality of support rods are fixedly connected to the side surface of the bracket, a stabilizing rod is provided between two brackets, the bracket and the stabilizing rod are connected by bolts, and a pulley is fixedly connected to the bottom of the bracket.

[0014] A combined mechanical and hydraulic method for dredging river silt includes the following steps:

[0015] Select a work area, assemble the equipment and fix it on both sides of the work area;

[0016] The hydraulic rod is activated to lower the soundproof cover with its flexible skirt into contact with the riverbed surface;

[0017] By applying continuous downward pressure to the cover structure through hydraulic rods to squeeze the silt layer it covers, and forcing the silt to pass through the filter screen under the squeezing action, the stones and other debris in the silt are separated and blocked outside the soundproof cover before the cutting operation begins.

[0018] The first and second cutting heads, which are set inside the soundproof enclosure, are activated to cut the sludge after pre-pressure filtration, and the mud formed by cutting is simultaneously sucked out from the soundproof enclosure.

[0019] While performing the cutting and conveying steps, a downward hydraulic curtain is formed by spraying water through nozzles around the outer perimeter of the soundproof enclosure to actively block the turbid water leakage from the flexible skirt.

[0020] In summary, the present invention has at least one of the following beneficial technical effects:

[0021] 1. This invention forms a closed physical working cover through the silent components and the flexible skirt at the bottom, completely isolating the cutting area from the external river water; at the same time, the barrier ring forms an active hydraulic curtain through the nozzle, which, as a second line of defense, can effectively intercept and suppress any mud that may leak from the skirt. Combined with the fully sealed delivery of the conveying hose, a triple protection system is formed, which fundamentally eliminates the problems of mud and sand diffusion and water turbidity. In addition, the cover structure also effectively suppresses noise transmission and protects the aquatic ecological environment.

[0022] 2. This invention applies pressure to the soundproof cover one via a hydraulic rod, forcing the sludge through the filter screen before actual cutting, separating hard debris such as stones and blocking them outside the work area in advance. This protects the subsequent cutting heads one and two from impact and wear from hard objects, extending equipment life and reducing failure rate. At the same time, the buffer mechanism composed of springs and telescopic rods can effectively dissipate impact force, further ensuring structural safety, making the entire dredging process more efficient, smooth, and reliable.

[0023] 3. The present invention adds pulleys to the bottom of the support, which allows the entire set of equipment to be easily and quickly moved along the riverbank to the next work station after completing the dredging of a strip area. This greatly reduces the auxiliary work and time required for equipment relocation and improves the continuous operation capability. In addition, combined with the precise lateral positioning function provided by the electric slide rail, the equipment can efficiently cover a large dredging area in a strip-like propulsion manner. The overall operation is flexible, highly automated, and reduces the intensity of manual intervention. Attached Figure Description

[0024] Figure 1 This is a perspective view of the present invention;

[0025] Figure 2 This is a diagram illustrating the present invention;

[0026] Figure 3 This is a schematic diagram of the transfer tube of the present invention;

[0027] Figure 4 This is a schematic diagram of the cutting frame of the present invention;

[0028] Figure 5 This is a schematic diagram of the gear of the present invention;

[0029] Figure 6 This is an internal view of the soundproof enclosure of the present invention;

[0030] Figure 7 This is a schematic diagram of the disturbance plate of the present invention;

[0031] Figure 8 This is a schematic diagram of the cutting head of the present invention.

[0032] The components are as follows: 1. Bracket; 2. Electric slide rail; 3. Slide seat; 4. Hydraulic rod; 5. Auxiliary rod; 6. Transfer pipe; 7. Cutting frame; 8. Waterproof motor; 9. Cutting head one; 10. Gear one; 11. Gear two; 12. Cutting head two; 13. Silent assembly; 1301. Sliding groove; 1302. Silent cover one; 1303. Silent cover two; 14. Groove; 15. Fixing ring; 16. Telescopic rod; 17. Spring; 18. Filter screen; 19. Leakage ring; 20. Nozzle; 21. Delivery hose; 22. Guide cover; 23. Disruptor plate; 24. Overflow hole; 25. Flexible skirt; 26. Support rod; 27. Stabilizing rod; 28. Bolt; 29. ​​Pulley; 30. Gear three. Detailed Implementation

[0033] The following is in conjunction with the appendix Figure 1 -Appendix Figure 8 The present invention will be further described in detail below.

[0034] This invention provides a mechanical and hydraulic combined river silt dredging device, comprising two supports 1, an electric slide rail 2 installed between the two supports 1, a slide block 3 slidably connected to the outside of the electric slide rail 2, a hydraulic rod 4 fixedly connected to the lower surface of the slide block 3, an auxiliary rod 5 connected to the output flange of the hydraulic rod 4, a transfer pipe 6 connected to the output flange of the auxiliary rod 5, a cutting frame 7 connected to the input flange of the transfer pipe 6, a waterproof motor 8 fixedly connected to the upper surface of the cutting frame 7, and the output end of the waterproof motor 8 passing through the cutting frame 7 and fixedly connected to a cutting... The output end of the waterproof motor 8 is also fixedly connected to the first gear 10. The first gear 10 is rotatably connected inside the cutting frame 7. Multiple second gears 11 are rotatably connected inside the cutting frame 7. The second gears 11 mesh with the first gear 10 through the third gear 30. The third gear 30 is rotatably connected inside the cutting frame 7. The lower surface of the second gear 11 is fixedly connected to the second cutting head 12. The second cutting head 12 is located outside the cutting frame 7. Multiple second cutting heads 12 are arranged in a ring array around the first cutting head 9. A silent component 13 is provided on the outside of the auxiliary rod 5.

[0035] Specifically, two supports 1 form a stable working foundation on both sides of the river channel. The electric slide rail 2 installed between them drives the slide block 3 to move the working components laterally, thereby accurately positioning the dredging area. The hydraulic rod 4 below the slide block 3 provides a strong vertical driving force to push the entire working system down and apply key pre-pressure to the riverbed silt. The output auxiliary rod 5, as the core force transmission structure, transmits this downward pressure to the working end and connects to the transfer pipe 6, which serves as the mud suction inlet, and the cutting frame 7, which houses the entire cutting system. On the cutting frame 7, the waterproof motor 8 serves as the power source, directly driving the cutting head 9 to break up the central silt at high speed. It also connects the gear 10 to multiple gears 11 through the gear 30, synchronously driving the multiple cutting heads 12, which are arranged in a ring array, to rotate. This achieves large-area synchronous cutting, thereby significantly improving the efficiency of a single operation. Finally, the noise reduction component 13, located outside the auxiliary rod 5, encloses the entire cutting and disturbance process inside, achieving the core environmental protection effect of isolating the working area from the external water body, preventing mud diffusion, and suppressing noise from the source.

[0036] The noise reduction assembly 13 includes a sliding groove 1301, which is formed on the outer surface of the auxiliary rod 5. A noise reduction cover 1302 is slidably connected inside the sliding groove 1301. The noise reduction assembly 13 also includes a noise reduction cover 1303, which is fixedly connected to the side surface of the cutting frame 7 and is located inside the noise reduction cover 1302.

[0037] Specifically, the silencing component 13 guides the first silencing cover 1302 to slide smoothly down by its own weight through the sliding groove 1301 on the auxiliary rod 5 to achieve flexible contact with the riverbed, while the second silencing cover 1303 fixed on the cutting frame 7 acts as an inner layer of protection and moves synchronously with the cutting mechanism, together forming a double-layer telescopic isolation system.

[0038] The lower end of the inner surface of the soundproof cover 1302 is provided with a groove 14. Two fixing rings 15 are slidably connected to the two ends of the groove 14. Multiple telescopic rods 16 and multiple springs 17 are fixedly connected between the two fixing rings 15. The springs 17 are sleeved on the outside of the telescopic rods 16, near the input end of the soundproof cover 1302. A filter screen 18 is fixedly connected to the inner surface of the fixing rings 15.

[0039] Specifically, during the process of the silencing cover 1302 descending and applying pre-pressure to the sludge, the filter screen 18 installed in the groove 14, supported by the fixing ring 15, performs initial filtration on the squeezed sludge, blocking stones and other debris. At the same time, the buffer mechanism composed of multiple springs 17 and telescopic rods 16 can effectively absorb the impact force by stretching and deforming when the filter screen 18 encounters hard objects, thereby protecting the equipment structure.

[0040] A damping ring 19 is fixedly connected to the lower end of the outer surface of the soundproof cover 1302. The inside of the damping ring 19 is hollow. The output end of the damping ring 19 is connected to the outside. The output end of the damping ring 19 is connected to a nozzle 20.

[0041] Specifically, the damping ring 19, fixed to the outside of the soundproof enclosure 1302, sprays water downwards through the nozzle 20 on it, forming an active hydraulic curtain to block any mud that may leak from the seal.

[0042] The output end of the transfer pipe 6 is connected to the delivery hose 21, and the output end of the delivery hose 21 passes through the soundproof cover 1302 and is connected to the outside.

[0043] Specifically, the pre-treated and cut mud is sucked into the transfer pipe 6 and then transported directly to the shore in a fully enclosed manner by the delivery hose 21, eliminating the possibility of secondary pollution.

[0044] The soundproof enclosure 1302 has a guide cover 22 fixedly connected inside, and a disturbance plate 23 is fixedly connected to the lower surface of the guide cover 22.

[0045] Specifically, inside the silencing enclosure 1302, the guide cover 22 and the disturbance plate 23 below work together to disturb and break up the sludge entering the enclosure, thereby reducing its viscosity and creating favorable conditions for subsequent efficient cutting and suction.

[0046] The top of the soundproof enclosure 1302 has multiple overflow holes 24, which pass through the soundproof enclosure 1302.

[0047] Specifically, to ensure operational safety, the multiple overflow holes 24 on the top of the soundproof enclosure 1302 can drain excess water when the pressure inside the enclosure is abnormal, playing a key role in stabilizing the system pressure.

[0048] A flexible skirt 25 is fixedly connected to the lower surface of the soundproof cover 1302, and the spray direction of the nozzle 20 is towards the outside and below of the flexible skirt 25.

[0049] Specifically, the flexible skirt 25 at the bottom of the silencing cover 1302 serves as the first physical defense line. With its flexibility, it fits tightly against the riverbed, effectively isolating the work area. The nozzle 20, with its optimized spray direction, further enhances the sealing effect here.

[0050] Multiple support rods 26 are fixedly connected to the side surface of the bracket 1, and a stabilizing rod 27 is provided between two brackets 1. The bracket 1 and the stabilizing rod 27 are connected by bolts 28, and a pulley 29 is fixedly connected to the bottom of the bracket 1.

[0051] Specifically, the stable operation of the entire equipment relies on the secure locking provided by multiple support rods 26, as well as the robust frame composed of stabilizing rods 27 and bolts 28. When it is necessary to change work positions, the pulleys 29 at the bottom of the bracket 1 facilitate the easy movement of the equipment, enabling efficient continuous operation.

[0052] A combined mechanical and hydraulic method for dredging river silt includes the following steps:

[0053] Select a work area, assemble the equipment and fix it on both sides of the work area;

[0054] The hydraulic rod 4 is activated to lower the soundproof cover 1302 with flexible skirt 25 and bring it into contact with the riverbed surface;

[0055] The hydraulic rod 4 applies continuous downward pressure to the cover structure to squeeze the silt layer it covers, and forces the silt to pass through the filter screen 18 under the squeezing action, thereby pre-separating and blocking stones and other debris in the silt outside the soundproof cover 1302 before the cutting operation begins.

[0056] The cutting head 9 and cutting head 12, which are installed inside the soundproof enclosure 1302, are activated to cut the sludge after pre-pressure filtration, and at the same time the mud formed by cutting is sucked out from the soundproof enclosure 1302 in a sealed manner.

[0057] While performing the cutting and conveying step, a downward hydraulic curtain is formed by spraying water from nozzles 20 around the outer perimeter of the soundproof cover 1302 to actively block the turbid water leakage from the flexible skirt 25.

[0058] Working principle: In actual use, the location to be dredged and the approximate condition of the silt at that location are first determined. Then, multiple support rods 26 are used to stabilize two supports 1 on the bank respectively, and bolts 28 are used to connect the stabilizing rods 27 between the two supports 1 to form an overall frame. At the same time, the electric slide rail 2 is fixed between the two supports 1. During operation, the electric slide rail 2 installed between the supports 1 drives the slide block 3 to move laterally to determine the dredging location. Then, the hydraulic rod 4 extends, pushing the auxiliary rod 5, transfer pipe 6 and cutting frame 7 at its lower end to descend as a whole. At the same time, the soundproof cover 1302 will slide down along the sliding groove 1301 on the outer wall of the auxiliary rod 5 under its own weight until the soundproof cover 1302 slides down. The flexible skirt 25 at the bottom of 302 fits tightly against the uneven riverbed to isolate the work area. Then, the hydraulic rod 4 continues to descend, and the soundproof cover 1302 moves relative to the auxiliary rod 5 until the soundproof cover 1302 touches the top of the sliding groove 1301. As the hydraulic rod 4 continues to descend, it causes the soundproof cover 1302 to compress the silt layer. Meanwhile, another part of the soundproof cover 1303 moves inside the soundproof cover 1302 along with the cutting frame 7. The compressed silt is filtered by the filter screen 18, isolating stones and other debris, while the silt enters the interior of the soundproof cover 1302. When the compressed silt encounters hard objects, the spring 17, which is sleeved on the outside of the telescopic rod 16, supports the two fixed rings 15. This achieves the effect of mitigating the impact force on the filter screen 18; inside the soundproof enclosure 1302, the adhesion between the sludge particles is further broken by the disturbance of the guide cover 22 and the disturbance plate 23; then the waterproof motor 8 starts, and its output end directly drives the cutting head 9 to rotate at high speed to crush the central sludge. On the other hand, the gear 10 transmits the power of the waterproof motor 8 to multiple gears 11 through the gear 30. Then, the gears 11 synchronously drive multiple cutting heads 12 to rotate to achieve large-area and efficient cutting. At the same time as cutting, the damping ring 19 located outside the soundproof enclosure 1302 is connected to the external water supply equipment and sprays water downward through the nozzle 20 to form a hydraulic curtain. The screen actively blocks any turbid mud that may leak from the skirt; the mud is sucked into the transfer pipe 6 and then directly and sealed to the shore through the delivery hose 21; if too much water is sucked into the enclosure and causes abnormal pressure, the excess clean water can be discharged through multiple overflow holes 24 on the top of the silent enclosure 1302 to ensure system stability; after the silt in the entire transverse track direction is cleared, the support rod 26 is released from locking the support 1, and then the mobile device is moved to the other working areas through the pulleys 29 at the bottom of the support 1; finally, through this combination of mechanical cutting and hydraulic sealing, the effect of environmentally friendly dredging of the river is achieved without disturbing the water, without damaging the ecology and with significantly reduced noise and vibration.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mechanical and hydraulic combined river silt dredging device, comprising two supports (1), characterized in that, An electric slide rail (2) is installed between the two brackets (1). A slide block (3) is slidably connected to the outside of the electric slide rail (2). A hydraulic rod (4) is fixedly connected to the lower surface of the slide block (3). An auxiliary rod (5) is connected to the output flange of the hydraulic rod (4). A transfer pipe (6) is connected to the output flange of the auxiliary rod (5). A cutting frame (7) is connected to the input flange of the transfer pipe (6). A waterproof motor (8) is fixedly connected to the upper surface of the cutting frame (7). The output end of the waterproof motor (8) passes through the cutting frame (7) and is fixedly connected to a cutting head (9). A tooth is also fixedly connected to the output end of the waterproof motor (8). Gear 1 (10) is rotatably connected inside the cutting frame (7). Multiple gears 2 (11) are rotatably connected inside the cutting frame (7). Gears 2 (11) mesh with gear 1 (10) through gear 3 (30). Gear 3 (30) is rotatably connected inside the cutting frame (7). A cutting head 2 (12) is fixedly connected to the lower surface of gear 2 (11). The cutting head 2 (12) is located outside the cutting frame (7). Multiple cutting heads 2 (12) are arranged in a ring array around cutting head 1 (9). A silent component (13) is provided on the outside of the auxiliary rod (5). The noise reduction assembly (13) includes a sliding groove (1301) which is formed on the outer surface of the auxiliary rod (5). A noise reduction cover (1302) is slidably connected inside the sliding groove (1301). The noise reduction assembly (13) also includes a noise reduction cover (1303) which is fixedly connected to the side surface of the cutting frame (7). The noise reduction cover (1303) is located inside the noise reduction cover (1302). The inner surface of the first noise-retaining cover (1302) has a groove (14) at the lower end. Two fixing rings (15) are slidably connected to both ends of the groove (14). Multiple telescopic rods (16) and multiple springs (17) are fixedly connected between the two fixing rings (15). The springs (17) are sleeved on the outside of the telescopic rods (16) and are close to the input end of the first noise-retaining cover (1302). A filter screen (18) is fixedly connected to the inner surface of the fixing rings (15). A damping ring (19) is fixedly connected to the lower end of the outer surface of the silencing cover (1302). The inside of the damping ring (19) is hollow. The output end of the damping ring (19) is connected to the outside. The output end of the damping ring (19) is connected to a nozzle (20). The lower surface of the soundproof cover (1302) is fixedly connected with a flexible skirt (25), and the nozzle (20) sprays downward toward the outside of the flexible skirt (25).

2. The mechanical and hydraulic combined river silt dredging equipment according to claim 1, characterized in that, The output end of the transfer pipe (6) is connected to the delivery hose (21), and the output end of the delivery hose (21) passes through the soundproof cover (1302) and is connected to the outside.

3. The mechanical and hydraulic combined river silt dredging equipment according to claim 1, characterized in that, The soundproof enclosure (1302) is fixedly connected to a guide cover (22), and a disturbance plate (23) is fixedly connected to the lower surface of the guide cover (22).

4. The mechanical and hydraulic combined river silt dredging equipment according to claim 1, characterized in that, The top of the soundproof enclosure (1302) is provided with a plurality of overflow holes (24), which are through the soundproof enclosure (1302).

5. The mechanical and hydraulic combined river silt dredging equipment according to claim 1, characterized in that, The side surface of the bracket (1) is fixedly connected with a plurality of support rods (26), and a stabilizing rod (27) is provided between two brackets (1). The bracket (1) and the stabilizing rod (27) are connected by bolts (28). The bottom of the bracket (1) is fixedly connected with a pulley (29).

6. A combined mechanical and hydraulic method for dredging river silt, applied to the combined mechanical and hydraulic river silt dredging equipment described in any one of claims 1-5, characterized in that, Includes the following steps: Select a work area, assemble the equipment and fix it on both sides of the work area; The hydraulic rod (4) is activated to lower the soundproof cover (1302) with flexible skirt (25) and bring it into contact with the riverbed surface; The hydraulic rod (4) applies continuous downward pressure to the cover structure to squeeze the silt layer it covers, and forces the silt to pass through the filter screen (18) under the squeezing action, thereby pre-separating and blocking stones and other debris in the silt outside the soundproof cover (1302) before the cutting operation begins. The cutting head 1 (9) and cutting head 2 (12) installed inside the soundproof enclosure 1 (1302) are activated to cut the silt after pre-pressure filtration, and at the same time the mud formed by cutting is sucked out from the soundproof enclosure 1 (1302) in a sealed manner. While performing the cutting and conveying step, a downward hydraulic curtain is formed by spraying water through nozzles (20) around the outer periphery of the soundproof cover (1302) to actively block the turbid water leakage from the flexible skirt (25).

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