Layered hydraulic stripping silt reduction method and device for bottom mud of urban river

Abstract

The invention discloses an urban river sediment layering hydraulic stripping silt reduction method and device, and belongs to the technical field of urban river ecological governance, the device comprises two floating platforms, first electric push rods are rotatably mounted at the two ends of the upper surfaces of the two floating platforms, and piston rods of the four first electric push rods are rotatably mounted at the four corners of the lower surface of a mounting platform; an n-shaped rod is fixedly mounted at one end of the upper surface of the mounting table, a sludge sweeping mechanism is rotationally mounted between the two ends of the outer surface of the n-shaped rod, a conical barrel is fixedly mounted on the lower surface of the mounting table, and convex frames are rotationally mounted on the two sides of the lower surface of the conical barrel. Through the design of the mud sweeping mechanism and the hydraulic stripping mechanism, closed-loop operation of supporting stability adjustment, layered stripping, suspension interception, mud-water separation and bottom mud collection is achieved, the accuracy of layered silt reduction is ensured, bottom layer inert mud disturbance and water body secondary pollution are avoided, the low-noise design meets the operation requirement of a residential area, and the application range is wide. The dredging efficiency is obviously improved; and the disposal cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of urban river ecological management, in particular to a method and device for layered hydraulic stripping and silt reduction of urban river sediment. BACKGROUND

[0002] As an important carrier of urban water cycle, urban river not only bears the functions of flood control and drainage, but also provides ecological landscape services for residents. However, for a long time, factors such as direct discharge of urban domestic sewage, surface runoff scouring, and deposition of aquatic organism residues have led to the accumulation of a large amount of pollutants (such as organic matter, nitrogen and phosphorus nutrients, heavy metals, and microplastics) in the bottom of the river, forming sediment. Data shows that the sediment accumulation thickness of most urban rivers can reach 0.3-1.5m, among which the COD (Chemical Oxygen Demand) concentration of the surface layer 0-30cm sediment is generally more than 200mg / kg, and the TP (Total Phosphorus) concentration is more than 1000mg / kg, belonging to the heavy pollution layer; the middle layer 30-80cm is a transition layer, although the pollutant concentration is lower than that of the surface layer, there is still a risk of release; the bottom layer 80cm below is mostly inert sandy or clayey, with low pollutant content, and is an important part of the ecological substrate of the river bed.

[0003] A kind of urban river dredging equipment is disclosed in Chinese authorized patent with publication number CN220013814U, comprising a bottom plate, a drain, a mud pump, the bottom plate top is fixedly connected with support, and the support one end is fixedly connected with box, the box bottom surface one side is fixedly installed with drain, and the box top is fixedly connected with second hydraulic telescopic rod.The utility model discloses, by putting the mud pump into the river that needs to be cleaned, the sludge in the river is separated by starting the mud pump through the operation panel, at the same time, the sludge is separated by the soft tube, the water pipe and is transferred to the box, the sludge is pushed out from the hinged plate by the push plate, the water in the sludge is discharged by extrusion, so as to achieve the purpose of facilitating the sludge cleaning and transfer, after the sludge is cleaned, the water pump is started through the operation panel, the water pump is guided to the spray head through the water supply pipe, and the surface of the filter screen plate is washed through the spray head.

[0004] However, the above-mentioned urban river dredging equipment still has many technical limitations and cannot meet the needs of fine silt reduction of urban rivers. Firstly, it lacks layered processing capability and adopts a "non-discriminatory mud pumping" mode, which cannot distinguish between surface contaminated sediment, middle transition sediment and bottom inert sediment, and easily pumps out the bottom ecological substrate together, damaging the river bed structure and causing embankment foundation exposure or loss of aquatic habitat. Secondly, the bottom mud stripping efficiency is low, only relying on the negative pressure suction of the mud pump to collect the sludge, it is difficult to effectively strip the middle layer of the bottom mud with high consolidation degree (particle size 0.02-0.1mm), and the problem of "not completely pumped" is easy to occur, and the dredging is easy to accumulate again in a short period of time; Thirdly, the water body is disturbed and the risk of secondary pollution is high, there is no targeted suspended mud interception design during the mud pumping process, and the fine particle bottom mud (particle size <5mm) is easy to diffuse to the downstream along with the water flow, resulting in the rapid increase of the SS (suspended matter) concentration in the water body (often more than 200mg / L), and causing the blackening of the water body to be intensified; Fourthly, the adaptability is poor, the equipment relies on the support of the bottom plate and the support, and is only suitable for the river with shallow water depth (<1m) and flat bed surface, for the urban main river with water depth of 1-5m or the bed surface undulating area, the support is unstable, the mud pumping port cannot reach the river bottom, and the overall volume is large, it is difficult to enter the narrow river with a width of <5m for operation, in addition, the running noise of the mud pump and the crushing cutter of the above-mentioned equipment exceeds 75dB, which is easy to interfere with the surrounding residents' life. SUMMARY

[0005] The purpose of the present application is to provide a kind of urban river bottom mud layered water force stripping and silt reduction method and device, to solve the above-mentioned problems that the above-mentioned urban river dredging equipment cannot realize bottom mud layered treatment, bottom mud stripping is not complete, water body is disturbed greatly during operation, and it is difficult to adapt to complex urban river scene in the background art.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A kind of urban river bottom mud layered water force stripping and silt reduction device, comprising: two groups of floating platform, the upper surface of two groups of the floating platform both ends are rotatably installed with first electric push rod, the piston rod of four groups of the first electric push rod is rotatably installed on the lower surface of installation platform four corners;Two groups of the upper surface of floating platform both ends are rotatably installed with connecting arm, and the other end of every two groups of the connecting arm is rotatably installed in the middle segment position of the lower surface of installation platform; The upper surface of the installation platform is fixedly installed with the L-shaped rod at one end, the outer surface of the L-shaped rod is rotatably installed with the mud sweeping mechanism between both ends, the mud sweeping mechanism can realize the action of exploring into different depth positions in the river by rotating on the outer surface of the L-shaped rod.

[0007] The urban river channel sediment layering water force stripping and silt reducing device, wherein: the lower surface of the installation table is fixedly installed with a conical cylinder, the lower surface of the conical cylinder is rotatably installed with a convex frame on both sides, and the convex frame is shrinkably installed with a water force stripping mechanism; one end of the outer surface of the convex frame is fixedly installed with a connecting rod, the connecting rod is rotatably connected with the piston rod of the second electric push rod, and the other end of the second electric push rod is rotatably installed at one end of the installation table; the second electric push rod can pull back the connecting rod through the piston rod, drive the convex frame to rotate downward around the rotation connection point of the convex frame and the conical cylinder; through the rotation of the convex frame, the water force stripping mechanism inside the convex frame can adjust the inclination angle of the water force stripping mechanism inserted into the river channel, and the water force stripping mechanism can extend to the river bottom at the angle; the upper surface of the installation table is fixedly installed with a towing hook.

[0008] The urban river channel sediment layering water force stripping and silt reducing device, wherein: the lower surface of the installation table is fixedly installed with a conical cylinder, the lower surface of the conical cylinder is rotatably installed with a convex frame on both sides, and the convex frame is shrinkably installed with a water force stripping mechanism; one end of the outer surface of the convex frame is fixedly installed with a connecting rod, the connecting rod is rotatably connected with the piston rod of the second electric push rod, and the other end of the second electric push rod is rotatably installed at one end of the installation table; the second electric push rod can pull back the connecting rod through the piston rod, drive the convex frame to rotate downward around the rotation connection point of the convex frame and the conical cylinder; through the rotation of the convex frame, the water force stripping mechanism inside the convex frame can adjust the inclination angle of the water force stripping mechanism inserted into the river channel, and the water force stripping mechanism can extend to the river bottom at the angle; the upper surface of the installation table is fixedly installed with a towing hook.

[0009] The urban river channel sediment layering water force stripping and silt reducing device, wherein: the lower surface of the installation table is fixedly installed with a conical cylinder, the lower surface of the conical cylinder is rotatably installed with a convex frame on both sides, and the convex frame is shrinkably installed with a water force stripping mechanism; one end of the outer surface of the convex frame is fixedly installed with a connecting rod, the connecting rod is rotatably connected with the piston rod of the second electric push rod, and the other end of the second electric push rod is rotatably installed at one end of the installation table; the second electric push rod can pull back the connecting rod through the piston rod, drive the convex frame to rotate downward around the rotation connection point of the convex frame and the conical cylinder; through the rotation of the convex frame, the water force stripping mechanism inside the convex frame can adjust the inclination angle of the water force stripping mechanism inserted into the river channel, and the water force stripping mechanism can extend to the river bottom at the angle; the upper surface of the installation table is fixedly installed with a towing hook.

[0010] The urban river channel sediment layering water force stripping and silt reducing device, wherein: the lower surface of the installation table is fixedly installed with a conical cylinder, the lower surface of the conical cylinder is rotatably installed with a convex frame on both sides, and the convex frame is shrinkably installed with a water force stripping mechanism; one end of the outer surface of the convex frame is fixedly installed with a connecting rod, the connecting rod is rotatably connected with the piston rod of the second electric push rod, and the other end of the second electric push rod is rotatably installed at one end of the installation table; the second electric push rod can pull back the connecting rod through the piston rod, drive the convex frame to rotate downward around the rotation connection point of the convex frame and the conical cylinder; through the rotation of the convex frame, the water force stripping mechanism inside the convex frame can adjust the inclination angle of the water force stripping mechanism inserted into the river channel, and the water force stripping mechanism can extend to the river bottom at the angle; the upper surface of the installation table is fixedly installed with a towing hook.

[0011] The city river channel bottom mud stratified water force stripping and silt reducing device, wherein: one end of the square plate is fixedly installed with a second motor in an embedded manner; the output shaft of the second motor and one end of one set of transmission columns are fixedly installed with transmission discs; the outer surfaces of the two sets of transmission discs are sleeved with synchronous belts; the second motor can drive the transmission columns to rotate through the synchronous belts; the rotating transmission columns can drive the conveying belts sleeved on the outer surfaces to operate, so that the conveying belts drive the mud scooping nets to scoop up the suspended bottom mud in the river channel and discharge the bottom mud into the receiving hopper.

[0012] The city river channel bottom mud stratified water force stripping and silt reducing device, wherein: one end of the square plate is fixedly installed with a second motor in an embedded manner; the output shaft of the second motor and one end of one set of transmission columns are fixedly installed with transmission discs; the outer surfaces of the two sets of transmission discs are sleeved with synchronous belts; the second motor can drive the transmission columns to rotate through the synchronous belts; the rotating transmission columns can drive the conveying belts sleeved on the outer surfaces to operate, so that the conveying belts drive the mud scooping nets to scoop up the suspended bottom mud in the river channel and discharge the bottom mud into the receiving hopper.

[0013] The city river channel bottom mud stratified water force stripping and silt reducing device, wherein: the water force stripping mechanism comprises two sets of scissor-type telescopic arms, and one end of the tail portions of the two sets of scissor-type telescopic arms is rotatably installed in the convex-shaped frame; the upper and lower surfaces of the hinge shafts hingedly connected at the centers of the scissor-type telescopic arms are fixedly installed with slip rings and lock rings, respectively; the slip rings are slidably installed in installation cavities through slide slot openings; the installation cavities are formed in the upper half portions of the convex-shaped frame; the slide slot openings are formed in the inner upper surfaces of the installation cavities; one end of the installation cavities is fixedly installed with a fourth electric push rod, and the piston rod of the fourth electric push rod is rotatably connected with one of the slip rings sliding into the installation cavity.

[0014] The city river channel bottom mud stratified water force stripping and silt reducing device, wherein: the lock rings are fixedly installed with corrugated pipes, and one end of the two sets of corrugated pipes is communicatively installed with a high-pressure nozzle; the other end of the corrugated pipe penetrates through one end of the convex-shaped frame and is communicatively installed with the liquid outlet of an external water pump; the liquid inlet of the external water pump can be directly placed into the river channel to suck the river water in the river channel.

[0015] The application also provides a city river channel bottom mud stratified water force stripping and silt reducing method, which comprises the following steps: S1, before the bottom mud silt reducing operation on the target river channel, survey points are arranged along the target river channel in a left-middle-right direction every 50 m, and a 1.5 m columnar sampler is used to collect bottom mud samples at the survey points; S2, analyze the particle size distribution of the sediment sample in the laboratory by screening method, determine that the surface sediment is floating mud with particle size <0.05mm, the middle layer sediment is transition mud with particle size 0.05-0.1mm, and the bottom layer sediment is inert sand mud with particle size >0.1mm, simultaneously detect the COD concentration, TP concentration and water content of the surface sediment, middle layer sediment and bottom layer sediment respectively, and clarify the thickness boundary and physical and chemical properties of the three layers of sediment; S3, according to the stratification characteristics of the three layers of sediment, match the operation parameters of the urban river sediment stratified hydraulic stripping and silt reduction device, connect the device to the towing hook of the towing ship or the onshore traction equipment, and tow the device to the working area of the target river; S4, control the extension and retraction of the four groups of first electric push rods of the device, adjust the levelness and height of the mounting table of the device relative to the floating platform, and make the device maintain a stable working posture on the complex water surface of the river; S5, control the extension and retraction of the second electric push rod of the device, push the connecting rod through the piston rod of the second electric push rod, drive the convex frame and the hydraulic stripping mechanism inside it to rotate around the hinge point of the convex frame and the conical cylinder, and adjust the high-pressure nozzle of the hydraulic stripping mechanism to the preset working angle and depth with the riverbed; S6, start the water pump connected with the bellows of the hydraulic stripping mechanism, the water pump pumps and pressurizes the river water, forms high-speed water flow and delivers it to the high-pressure nozzle; S7, control the extension and retraction of the fourth electric push rod of the device, drive the scissor-type telescopic arm to expand or shrink in the convex frame, and adjust the distance between the high-pressure nozzle and the riverbed surface and the spraying coverage; S8, by controlling the output pressure of the water pump, the distance between the high-pressure nozzle and the riverbed surface, and the advancing speed of the device, use the high-speed water flow sprayed by the high-pressure nozzle to accurately, stratifiedly and controllably impact and strip the riverbed sediment, and avoid excessive disturbance to the bottom layer inert sand mud; S9, after completing the stripping of the surface sediment, control the extension and retraction of the third electric push rod of the device, push the mud sweeping mechanism to rotate around the convex rod, and adjust the conveying belt and the mud scooping net of the mud sweeping mechanism to the preset scooping depth; S10, start the second motor of the mud sweeping mechanism, rotate the transmission column through the synchronous belt drive, and then drive the conveying belt to operate; S11, use the mud scooping net to scoop the suspended sediment in the river caused by the hydraulic stripping and the original suspended pollutants in the river, after the mud scooping net is lifted to the preset height with the conveying belt, the scooped sediment and suspended pollutants are thrown into the receiving hopper, and the sediment and suspended pollutants fall into the conical cylinder along the receiving hopper, completing the preliminary collection of the surface suspended matter; S12, the suspended slurry mixture formed after stripping by the high-pressure nozzle enters the conveying pipe under the collection and guidance of the conical cylinder; S13, start the first motor of the device, drive the spiral conveying blade in the conveying pipe to rotate, and push the high-concentration slurry mixture in the conveying pipe upward to the position where the L-shaped pipe and the filter screen are located; S14, during the vertical conveying along the L-shaped pipe, part of the water in the slurry mixture is separated by pressure filtration through the filter screen under the action of gravity, and the separated water flows back to the river channel; S15, the preliminary dewatered sediment continues to be conveyed along the L-shaped pipe to the temporary storage in the sludge collecting cabin, or is conveyed to the subsequent treatment equipment through the external pipeline, and the river sediment reduction operation is completed.

[0016] Compared with the prior art, the beneficial effects of the present application are: 1. The device relies on the buoyancy of two groups of floating platforms for support, does not need to rely on the river bed surface, can be suspended for operation, can adapt to urban rivers with a water depth of 1-5 m, can be flexibly towed to narrow rivers or complex river sections by connecting the towing hook with the towing ship / land traction equipment, solves the pain points of traditional large-scale dredging equipment that "cannot enter" and "cannot turn", and the first electric push rod and the connecting arm cooperatively adjust the level and height of the installation table, can cope with water level fluctuations, and ensure stable operation in different river environments.

[0017] 2. A differential stripping scheme is designed for surface contaminated sediment (0-30 cm) and middle layer transition sediment (30-80 cm), the surface is scattered with low-pressure water flow of 0.3-0.5 MPa, the middle layer is sheared with high-pressure water flow of 0.6-0.8 MPa, and the distance between the high-pressure nozzle and the river bottom is controlled (100-150 mm / 50-100 mm) through the angle adjustment (30° / 45°) of the convex frame to accurately avoid the inert mud layer of >80 cm, the depth meter is monitored every 5 minutes to ensure that the residual layer is ≥20 cm, to avoid damaging the ecological structure of the river bed surface and the aquatic habitat, and to realize the cooperation of "silt reduction" and "ecological protection".

[0018] 3. The water power stripping operation synchronously starts the mud sweeping mechanism, the conveying belt and the mud net are circulated through the second motor, the accurate depth of 100-150 mm of the surface and 200-250 mm of the middle layer can instantly intercept the suspended sediment, the suspended sediment is collected into the conical cylinder through the receiving hopper, the suspended sediment is prevented from diffusing to the downstream, the SS concentration of the water body is monitored in real time (controlled to be ≤100 mg / L), the water flows back along the triangular guide plate after the separation of the sludge and water (SS≤50 mg / L), the whole process reduces the release of pollutants, and solves the problem of "the more you clean, the dirtier it is" of traditional dredging. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic structural view of the overall top view of the present application; Figure 2 is a schematic structural view of the overall bottom view of the present application; Figure 3This is a schematic diagram of the overall side cross-section of the present invention; Figure 4 This is a schematic diagram of the mud collection chamber and conical cylinder of the present invention; Figure 5 This is a schematic diagram of the sludge removal mechanism of the present invention; Figure 6 This is a schematic diagram of the sealing tube and convex frame of the present invention; Figure 7 This is a schematic diagram of the scissor-type telescopic arm and the bellows of the present invention; Figure 8 This is a schematic diagram of the hydraulic stripping mechanism of the present invention.

[0020] In the diagram: 1. Floating platform; 101. Mounting platform; 102. Mud collection hopper; 103. Tow hook; 104. U-shaped rod; 105. Mounting cavity; 106. First electric push rod; 107. Connecting arm; 108. Triangular guide plate; 109. Convex frame; 110. Conveying pipe; 111. L-shaped pipe; 112. Filter screen; 113. Conical cylinder; 114. First motor; 115. Second electric push rod; 116. Sliding bar opening; 117. Connecting rod; 118. Dense 1. Sealing pipe; 119. Receiving hopper; 120. Spiral conveyor blade; 2. Sludge sweeping mechanism; 201. Connecting plate; 202. Transmission column; 203. Conveyor belt; 204. Sludge scooping net; 205. Transmission disc; 206. Second motor; 207. Third electric push rod; 208. Square plate; 3. Hydraulic stripping mechanism; 301. Scissor telescopic arm; 302. Locking ring; 303. Corrugated pipe; 304. High-pressure nozzle; 305. Slip ring; 306. Fourth electric push rod. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 1-4 As shown, this embodiment provides a hydraulic stripping and silt reduction device for stratified sediment in urban riverbeds, comprising: two sets of floating platforms 1, each set of floating platforms 1 having a first electric push rod 106 rotatably mounted at both ends of its upper surface, and piston rods of four sets of first electric push rods 106 rotatably mounted at the four corners of the lower surface of the mounting platform 101; each set of floating platforms 1 also has a connecting arm 107 rotatably mounted at both ends of its upper surface, and the other end of each pair of connecting arms 107 arranged opposite to each other is rotatably mounted at the middle section of both ends of the lower surface of the mounting platform 101. The upper surface of the installation table 101 is fixedly installed with a T-shaped rod 104, and the outer surface of the T-shaped rod 104 is rotatably installed with a mud sweeping mechanism 2. The mud sweeping mechanism 2 can be rotated on the outer surface of the T-shaped rod 104 to realize the action of exploring different depths in the river channel. The lower surface of the installation table 101 is fixedly installed with a conical cylinder 113, and the lower surface of the conical cylinder 113 is rotatably installed with a convex frame 109. The convex frame 109 is shrinkably installed with a hydraulic stripping mechanism 3. The outer surface of the convex frame 109 is fixedly installed with a connecting rod 117, and the connecting rod 117 is rotatably connected with the piston rod of a second electric push rod 115. The other end of the second electric push rod 115 is rotatably installed at one end of the installation table 101. The second electric push rod 115 can pull back the connecting rod 117 through the piston rod, so as to drive the convex frame 109 to rotate downward around the rotation connection point with the conical cylinder 113. Through the rotation of the convex frame 109, the hydraulic stripping mechanism 3 inside the convex frame 109 can adjust the inclination angle of the exploration into the river channel, and the hydraulic stripping mechanism 3 can extend to the river bottom at the angle. The upper surface of the installation table 101 is fixedly installed with a drag hook 103.

[0023] The lower surface of the conical cylinder 113 is communicatedly installed with a conveying pipe 110, and the conveying pipe 110 is located between the two groups of convex frames 109. The other end of the conveying pipe 110 is communicatedly installed with an L-shaped pipe 111, and the L-shaped pipe 111 penetrates through the triangular guide plate 108 and is vertically opposite to the mud collecting cabin 102. The mud collecting cabin 102 is fixedly installed on the upper surface of the installation table 101, and the triangular guide plate 108 is also fixedly installed on the upper surface of the installation table 101. The outer surface of the L-shaped pipe 111 penetrating through the upper end of the inclined sliding surface of the triangular guide plate 108 is communicatedly installed with a filter screen 112.

[0024] One end of the conveying pipe 110 is fixedly installed with a sealing pipe 118, and the first motor 114 is fixedly installed in the sealing pipe 118. The output shaft of the first motor 114 penetrates into the conveying pipe 110 through a sealing bearing, and the outer surface of the output shaft is fixedly installed with a spiral conveying blade 120. The spiral conveying blade 120 can rotate under the drive of the first motor 114 to push the mud into the L-shaped pipe 111 and convey it upward in the vertical direction. When the mud is conveyed to the position where the filter screen 112 is located, the water in the mud can be pressed out through the filter screen 112 under the action of natural gravity. The outer surface of the conical cylinder 113 is communicatedly installed with a receiving hopper 119, and the receiving hopper 119 is vertically opposite to the discharge end of the mud sweeping mechanism 2.

[0025] By the design of floating platform 1, mounting platform 101, sediment collecting tank 102, first electric push rod 106, connecting arm 107, triangular guide plate 108, convex frame 109, conveying pipe 110, L-shaped pipe 111, filter screen 112, conical cylinder 113, first motor 114, second electric push rod 115, receiving hopper 119, spiral conveying blade 120, mud sweeping mechanism 2 and hydraulic stripping mechanism 3, two groups of floating platforms 1 bear the mounting platform 101, sediment collecting tank 102, mud sweeping mechanism 2, hydraulic stripping mechanism 3 and all components by their own buoyancy, ensuring that the device is suspended on the water surface of the river to adapt to the scene of 1-5m water depth, the first electric push rod 106 at the four corners of the lower surface of the mounting platform 101 and the connecting arm 107 at the middle of both ends form a stable support structure, when the water surface of the river fluctuates or needs to adapt to different water depths, the four groups of first electric push rods 106 adjust the vertical height and horizontal attitude of the mounting platform 101 through synchronous or differential extension and contraction, and the connecting arm 107 adjusts the displacement of the mounting platform 101 by rotating to avoid its inclination imbalance, finally the mounting platform 101 remains horizontal and stable, providing a reference for subsequent operations, the towing hook 103 on the upper surface of the mounting platform 101 can be connected with a tugboat or a shore traction equipment, the device is dragged along the river longitudinally by external force to realize segmented operation of the whole river section, when it is in the layered stripping stage, the convex frame 109 installed on both sides of the conical cylinder 113 on the lower surface of the mounting platform 101 rotates to provide an angle adjustment basis for the hydraulic stripping mechanism 3, the connecting rod 117 at the outer end of the convex frame 109 is hinged with the piston rod of the second electric push rod 115, through the pullback or push of the piston rod of the second electric push rod 115, the convex frame 109 is rotated around the rotating connection point with the conical cylinder 113, and the inclination angle of the hydraulic stripping mechanism 3 into the river is adjusted, when the surface layer of bottom mud needs to be stripped, the convex frame 109 can be rotated to 30° and then the hydraulic stripping mechanism 3 is lengthened to approach the surface layer of mud at a gentle angle to avoid impacting the inert bottom mud, when the middle layer of bottom mud is stripped, the convex frame 109 is rotated to 45° to enhance the shearing force of the hydraulic stripping mechanism 3 on the consolidated bottom mud, the hydraulic stripping mechanism 3 extracts river water through an external water pump to differentially parameterize the surface and middle layers of bottom mud to be scattered or sheared, realizing layered targeted stripping, at the same time, the mud sweeping mechanism 2 at the H-shaped rod 104 on the upper surface of the mounting platform 101 is started synchronously, the mud sweeping mechanism 2 adjusts the depth and inclination angle into the river by rotating around the H-shaped rod 104, the surface layer is stripped to 100-150mm to correspond to the suspended surface layer, the middle layer is stripped to 200-250mm to correspond to the suspended middle layer, the suspended bottom mud generated by the hydraulic stripping is lifted by the self-powered driving structure of the mud sweeping mechanism 2, and the receiving hopper 119 at one end of the outer surface of the conical cylinder 113 is vertically opposite to the discharge end of the mud sweeping mechanism 2, the suspended bottom mud lifted by the mud sweeping mechanism 2 falls directly into the receiving hopper 119 and is collected into the conical cylinder 113 through the receiving hopper 119, and the mud-water mixture generated by the hydraulic stripping is concentrated and collected, then,The conveying pipe 110 connected with the lower surface of the conical cylinder 113 receives the sludge-water mixture in the conical cylinder 113. One end of the conveying pipe 110 is sealed in the sealed pipe 118. The first motor 114 is started, and the output shaft thereof drives the spiral conveying blade 120 in the conveying pipe 110 to rotate, so as to push the sludge-water mixture to the L-shaped pipe 111 connected with the other end of the conveying pipe 110. The L-shaped pipe 111 penetrates the triangular guide plate 108, and the bent part thereof is vertically opposite to the sludge collecting tank 102 on the upper surface of the mounting table 101. When the sludge-water mixture is pushed by the spiral conveying blade 120 to the vertical section of the L-shaped pipe 111 and reaches the filter screen 112 part at the upper end of the inclined sliding surface of the triangular guide plate 108, the water in the sludge-water mixture seeps out through the filter screen 112 under the joint action of the natural gravity and the spiral pushing pressure. The seeped water flows back to the river along the inclined surface of the triangular guide plate 108. The dewatered sludge continues to rise along the L-shaped pipe 111 and finally falls into the sludge collecting tank 102 from the bent part to complete the collection. When the sludge in the sludge collecting tank 102 reaches a certain capacity, the operation is paused, and the device is towed to the shore by a tugboat or traction equipment. The sludge in the sludge collecting tank 102 is transferred to a sealed tank truck by hoisting equipment for external transportation and disposal. The whole process realizes the closed-loop operation of "supporting and stabilizing - layered stripping - suspended interception - sludge-water separation - sludge collection", which not only ensures the accuracy of layered sediment reduction, but also avoids the disturbance of the inert sludge in the bottom layer and the secondary pollution of the water body.

[0026] As shown in Figure 5 The mud sweeping mechanism 2 includes two groups of square plates 208, which are rotatably installed at the two ends of the outer surface of the L-shaped rod 104. The outer surface of each group of square plates 208 is fixedly installed with a connecting plate 201 at one end. Two groups of transmission columns 202 are rotatably installed between the two groups of connecting plates 201. The outer surface of the two groups of transmission columns 202 is sleeved with a conveying belt 203. The outer surface of the conveying belt 203 is fixedly installed with a plurality of groups of mud fishing nets 204 at equal intervals.

[0027] One end of the square plate 208 is fixedly installed with a second motor 206 in an embedded manner. The output shaft of the second motor 206 and one end of one group of transmission columns 202 are fixedly installed with a transmission disc 205. The outer surfaces of the two groups of transmission discs 205 are sleeved with a synchronous belt. The second motor 206 can drive the transmission column 202 to rotate through the synchronous belt. The rotating transmission column 202 can drive the conveying belt 203 sleeved on the outer surface thereof to operate, so as to drive the mud fishing net 204 to fish up the suspended sludge in the river and discharge it into the receiving hopper 119.

[0028] The inner side of the connecting plate 201 is rotatably connected with the piston rod of the third electric push rod 207, and the third electric push rod 207 is rotatably installed on one end of the upper surface of the mounting table 101; the third electric push rod 207 can push the connecting plate 201 through the piston rod, so that the connecting plate 201 drives the conveying belt 203 and the mud net 204 to adjust the angle of inclination, and adjusts the depth of the mud net 204 into the river channel.

[0029] Through the design of the connecting plate 201, the transmission column 202, the conveying belt 203, the mud net 204, the transmission disc 205, the second motor 206 and the third electric push rod 207, the two square plates 208 are rotatably installed on both ends of the rectangular rod 104 as a support frame, and the inner side of the outer end fixed connecting plate 201 is rotatably connected with the piston rod of the third electric push rod 207; when the piston rod of the third electric push rod 207 is extended or retracted, it will push the connecting plate 201 to drive the square plate 208 to rotate around the rectangular rod 104, thereby adjusting the inclination angle of the transmission column 202, the conveying belt 203 and the mud net 204 between the two connecting plates 201 and the depth of the river channel. When the surface sediment is stripped, the third electric push rod 207 can push the piston rod to push the connecting plate 201, so that the conveying belt 203 penetrates into the river channel 100-150mm deep at an inclination angle of 30°; when the middle layer of sediment is stripped, the piston rod is further pushed to increase the inclination angle to 45°, and the penetration depth reaches 200-250mm, which ensures that the mud net 204 accurately covers the suspended sediment layer. The second motor 206 embedded in the square plate 208 is the power source, and its output shaft is connected with the transmission disc 205 at one end of one of the transmission columns 202 through a synchronous belt; when the second motor 206 is started, the power is transmitted to the transmission disc 205 through the synchronous belt, which drives the transmission column 202 to rotate, thereby driving the conveying belt 203 between the two transmission columns 202 to move in a cycle. The mud net 204 installed on the outer surface of the conveying belt 203 moves with the belt body, and when it penetrates into the river channel, it lifts the suspended sediment; when it moves to the top end of the conveying belt 203, the sediment is separated from the mud net 204 due to gravity and falls into the receiving hopper 119 opposite to the discharge end of the mud sweeping mechanism 2, and finally flows into the conical cylinder 113 through the receiving hopper 119 to complete the collection, so that the depth adjustment of the third electric push rod 207 and the cycle of the mud driven by the second motor 206 can intercept the suspended sediment generated by the water force stripping in real time, avoid its diffusion and pollution to the downstream water body, and provide a front guarantee for the subsequent separation of mud and water.

[0030] As Figures 6-8As shown, the hydraulic stripping mechanism 3 includes two groups of scissor type telescopic arms 301, the tail end of which is rotatably installed in the convex frame 109; the upper and lower surfaces of the hinge shaft at the center of the scissor type telescopic arm 301 are respectively fixedly installed with a slip ring 305 and a lock ring 302; the slip ring 305 is slidably installed in the installation cavity 105 through a sliding bar opening 116, the installation cavity 105 is opened in the upper half of the convex frame 109, and the sliding bar opening 116 is opened in the inner upper surface of the installation cavity 105; one end of the installation cavity 105 is fixedly installed with a fourth electric push rod 306, and the piston rod of the fourth electric push rod 306 is rotatably connected with one of the slip rings 305 which is slid through the installation cavity 105.

[0031] Among them, the lock ring 302 is fixedly installed with a corrugated pipe 303, and the two groups of corrugated pipes 303 are communicated between one end and are installed with a high-pressure nozzle 304; the other end of the corrugated pipe 303 is arranged through one end of the convex frame 109, and the end can be communicated and installed with the liquid outlet of the external water pump; the liquid inlet of the external water pump can be directly put into the river channel to suck the river water in the river channel.

[0032] Through the design of the scissor-type telescopic arms 301, the locking rings 302, the corrugated pipes 303, the high-pressure nozzles 304, the slip rings 305, and the fourth electric push rods 306, the two groups of scissor-type telescopic arms 301 are rotatably installed at the tail portions in the convex frame 109, and the upper and lower surfaces of the center hinge shafts are respectively fixed with the slip rings 305 and the locking rings 302, wherein the slip rings 305 pass through the slide bar openings 116 on the upper surface of the installation cavity 105 of the convex frame 109 and are rotatably connected with the piston rods of the fourth electric push rods 306 in the installation cavity 105, when the piston rods of the fourth electric push rods 306 are extended or retracted, the slip rings 305 are driven to slide horizontally along the slide bar openings 116, thereby driving the scissor-type telescopic arms 301 to expand or contract with the tail rotating points as the shafts, when the surface layer sediment is stripped, the piston rods push the slip rings 305 to fully expand the scissor-type telescopic arms 301, and the high-pressure nozzles 304 are pushed to a position with a distance of 100-150 mm from the river bottom, and when the middle layer sediment is stripped, the second electric push rods 115 push the scissor-type telescopic arms 301 to adjust to an inclination angle of 45°, and the high-pressure nozzles 304 at the tail ends of the scissor-type telescopic arms 301 are close to the river bottom along the inclination direction of the convex frame 109, then the piston rods pull the slip rings 305 to retract the scissor-type telescopic arms 301, and the distance is reduced to 50-100 mm, so as to adapt to the stripping requirements of the sediment at different depths, and ensure that the high-pressure water flow is accurately applied to the target layer, and the locking rings 302 are used to fix the corrugated pipes 303, so as to avoid the displacement of the pipes caused by water flow impact, one end of the two groups of corrugated pipes 303 is connected to the high-pressure nozzles 304, and the other end penetrates through the convex frame 109 and is connected with the outlet of the high-pressure water pump, the inlet of the water pump is directly put into the river to extract river water, and when the surface layer is stripped, the water pump outputs a low-pressure water flow with a pressure of 0.3-0.5 MPa and a large flow rate of 100-150 m³ / h, the water flow is transported to the high-pressure nozzles 304 through the corrugated pipes 303, so as to disperse the loose and polluted sediment on the surface layer with gentle water flow, when the middle layer is stripped, the pressure of the water pump is increased to 0.6-0.8 MPa, and the flow rate is adjusted to 50-80 m³ / h, the high-pressure nozzles 304 spray high-intensity water flow to shear the consolidated sediment in the middle layer, and in this process, the corrugated pipes 303 can be flexibly deformed with the expansion / retraction of the scissor-type telescopic arms 301, so as to always maintain stable water flow transportation, avoid pipe bending and breaking, at the same time, the rigid support of the scissor-type telescopic arms 301 and the accurate sliding of the slip rings 305 ensure the stable position of the high-pressure nozzles 304 during the stripping process, which not only avoids excessive diffusion of the water flow to disturb the inert sediment in the bottom layer, but also ensures the complete stripping of the sediment, and lays a foundation for the subsequent collection of suspended sediment.

[0033] Specifically, in the embodiment, the urban river sediment layering hydraulic stripping and silt reduction device further comprises an equation for evaluating and controlling the layering stripping efficiency: ; wherein: η is the layering stripping efficiency (dimensionless), the value is closer to 1, the efficiency is higher; P is the output pressure of the water pump (MPa), which controls the impact intensity of the water flow; Q is the water flow rate (m³ / h), which affects the stripping range and speed; D is the distance between the high-pressure nozzle and the riverbed surface (mm), which affects energy attenuation and focusing; C is the cohesive force of the sediment (kPa), which reflects the sediment's resistance to stripping; ω is the water content of the sediment (%), which affects the sediment's flowability; ω sat is the saturated water content of the sediment (%); k is the efficiency coefficient, determined by the device structure and river environment; α, β, γ, δ, ε are empirical exponents, calibrated through field tests.

[0034] The units of kα, β, γ, δ, ε are dimensionless.

[0035] Equation derivation process: This equation is derived based on the balance between water flow impact force and sediment resistance to stripping in fluid mechanics: 1. Water flow impact energy: positively related to P·Q; 2. Energy attenuation: inversely proportional to a certain power of distance D; 3. Sediment resistance: related to cohesive force C and water content, the higher the water content, the easier the stripping; 4. Normalization: introduce (1-ω / ω sat ) to reflect the influence of water content on stripping difficulty.

[0036] By considering the above factors, through dimensional analysis and experimental data fitting, the above multivariate nonlinear equation is obtained.

[0037] Example: taking surface stripping as an example: Assumptions: P=0.4MPa; Q=120m³ / h; D=120mm; C=0.8kPa; ω=65%; ω sat =80%; k=1.2, α=0.7, β=0.5, γ=0.6, δ=0.4, ε=0.8.

[0038] Substitute the equation: ; That is, the stripping efficiency under this working condition is about 89%.

[0039] Parameter further explanation: Technical effects: Precise control: by monitoring parameters such as P, Q, D, C, ω in real time, dynamically adjusting operation parameters, and realizing precise control of layer stripping; Efficiency optimization: avoid excessive stripping or insufficient stripping, and protect the inert mud layer at the bottom; Energy saving and environmental protection: minimize water and electricity consumption while ensuring efficiency; Data-driven: provides core algorithm support for intelligent dredging system.

[0040] Working principle flow: 1. Data acquisition: real-time acquisition of P, Q, D through sensors, and C, ω, ω through pre-survey sat ; 2. Efficiency calculation: substitute into the equation to calculate the current η; 3. Parameter adjustment: if η is lower than the target value, adjust P, Q, D or travel speed; 4. Feedback control: form a "monitoring-computing-adjustment-execution" closed loop to continuously optimize the operation process.

[0041] The embodiment also provides a city river sediment layering hydraulic stripping and silt reduction method, comprising the following steps: S1, before carrying out sediment silt reduction operation on the target river, survey points are arranged every 50m along the longitudinal direction of the target river and in left-middle-right direction in the transverse direction, and a 1.5m columnar sampler is used to collect sediment samples at each survey point; S2, the particle size distribution of the sediment sample is analyzed by sieving method in the laboratory, the surface sediment is determined as floating mud with particle size <0.05mm, the middle layer sediment is determined as transition mud with particle size 0.05-0.1mm, and the bottom layer sediment is determined as inert sand mud with particle size >0.1mm, the COD concentration, TP concentration and water content of the surface sediment, middle layer sediment and bottom layer sediment are simultaneously detected, and the thickness boundary and physical and chemical properties of the three layers of sediment are determined; S3, according to the layering characteristics of the three layers of sediment, the operating parameters of the city river sediment layering hydraulic stripping and silt reduction device are matched, the device is connected with the tow hook 103 of the device through the tugboat or the onshore traction equipment, and the device is towed to the working area of the target river; S4, the four groups of first electric push rods 106 of the device are controlled to stretch and retract, the levelness and height of the mounting table 101 of the device relative to the floating platform 1 are adjusted, and the device is kept in a stable working posture on the complex water surface of the river; S5, the second electric push rod 115 of the device is controlled to stretch and retract, the connecting rod 117 is pushed by the piston rod of the second electric push rod 115, the convex frame 109 and the hydraulic stripping mechanism 3 in the convex frame 109 are driven to rotate around the hinge point of the convex frame 109 and the conical cylinder 113, and the high-pressure nozzle 304 of the hydraulic stripping mechanism 3 is adjusted to the preset working angle and depth of the riverbed; S6, the water pump connected with the bellows 303 of the hydraulic stripping mechanism 3 is started, the water pump pumps river water and pressurizes the river water, forms a high-speed water flow and delivers it to the high-pressure nozzle 304; S7, the fourth electric push rod 306 of the control device is extended or retracted to drive the scissor-type telescopic arm 301 to expand or shrink in the convex frame 109, so as to adjust the distance between the high-pressure nozzle 304 and the riverbed surface and the spraying coverage; S8, by controlling the output pressure of the water pump, the distance between the high-pressure nozzle 304 and the riverbed surface, and the running speed of the device, the high-speed water flow sprayed by the high-pressure nozzle 304 is used to accurately, layer by layer and controllably impact and strip the riverbed mud, so as to avoid excessive disturbance to the inert sand mud in the bottom layer; S9, after completing the surface layer mud stripping, the third electric push rod 207 of the device is extended or retracted to push the mud sweeping mechanism 2 to rotate around the L-shaped rod 104, so as to adjust the conveying belt 203 and the mud scooping net 204 of the mud sweeping mechanism 2 to the preset scooping depth; S10, the second motor 206 of the mud sweeping mechanism 2 is started to rotate the synchronous belt drive column 202, and then drive the conveying belt 203 to operate; S11, the mud scooping net 204 is used to scoop the surface layer mud suspended in the river channel due to the hydraulic stripping effect and the original suspended pollutants in the river channel, after the mud scooping net 204 is lifted to the preset height along with the conveying belt 203, the scooped mud and suspended pollutants are thrown into the receiving hopper 119, and the mud and suspended pollutants fall into the conical cylinder 113 along the receiving hopper 119, so as to complete the preliminary collection of the surface layer suspended matter; S12, the suspended mud-water mixture formed after the stripping by the high-pressure nozzle 304 is collected and guided into the conveying pipe 110 by the conical cylinder 113; S13, the first motor 114 of the device is started to drive the spiral conveying blade 120 in the conveying pipe 110 to rotate, so as to push the high-concentration mud mixture in the conveying pipe 110 upward to the position where the L-shaped pipe 111 and the filter screen 112 are located; S14, in the process of vertical conveying along the L-shaped pipe 111, part of the water in the mud mixture is separated by the filter screen 112 under the action of gravity, and the separated water flows back to the river channel; S15, the mud after the preliminary dehydration continues to be conveyed along the L-shaped pipe 111 to the temporary storage in the mud collecting cabin 102, or is conveyed to the subsequent treatment equipment through the external pipeline, so as to complete the riverbed mud reduction operation.

[0042] Working principle: First of all, through the towing hook 103 on the installation platform 101, connect the tugboat or shore traction equipment, drag the whole device to the target river operation section and make the center line coincide with the longitudinal axis of the river, two groups of floating platform 1 rely on their own buoyancy to bear the installation platform 101 and all components such as sediment collecting tank 102, mud sweeping mechanism 2 and hydraulic stripping mechanism 3, ensure that the device is suspended in the river water surface with water depth of 1-5m, then start four groups of first electric push rod 106, combined with the rotation of connecting arm 107, adjust the vertical height and horizontal attitude of installation platform 101 through synchronous or differential extension and retraction of piston rod, finally make the installation platform 101 keep horizontal and stable, provide reference for subsequent operation, then enter the layered hydraulic stripping link, start high-pressure water pump during surface stripping, extract river water through corrugated pipe 303 to high-pressure nozzle 304, disperse the surface 0-30cm contaminated sediment with 0.3-0.5MPa low pressure and 100-150m³ / h large flow, realize uniform stripping of the whole section by towing the device at a uniform speed of 0.5-1m / min through the tugboat, real-time monitoring of water SS concentration is controlled to be less than or equal to 100mg / L, after the completion of surface stripping, the remaining thickness is less than 5mm measured by depth finder, switch to middle layer stripping mode, adjust the angle of convex frame 109 to 45°, shorten the distance between high-pressure nozzle 304 and river bottom to 50-100mm, adjust the water pump parameters to 0.6-0.8MPa high pressure / 50-80m³ / h flow, enhanced water flow shear force to strip middle layer consolidated bottom mud, every 5min to detect bottom layer inert mud thickness to ensure remaining ≥20cm, continue to drag the device at a uniform speed and monitor the SS concentration; and start the second motor 206 of the mud sweeping mechanism 2 at the same time as the start of the hydraulic stripping, the power is transmitted to the transmission disc 205 and the transmission column 202 through the synchronous belt, driving the conveyor belt 203 and the mud net 204 to move in a cycle, the mud net 204 is inserted 100-150mm to collect suspended mud during surface stripping, and the insertion depth is increased to 200-250mm during middle layer stripping, the bottom mud lifted by the conveyor belt 203 is dropped into the receiving hopper 119 at the top end due to gravity, and then the mud water mixture is collected and stored through the receiving hopper 119, and then the first motor 114 in the sealed pipe 118 at one end of the conveying pipe 110 is started, the output shaft drives the spiral conveying blade 120 to rotate through the sealed bearing, and the mud water mixture in the conical cylinder 113 is pushed to the L-shaped pipe 111, when the mixture rises to the filter screen 112 along the vertical section of the L-shaped pipe 111, the water is filtered out through the filter screen 112 under the action of pressure and gravity, and flows back to the river along the triangular guide plate 108, and the dewatered bottom mud falls into the mud collecting tank 102 for storage, until the capacity of the mud collecting tank 102 reaches 80%, all operations are suspended, the device is dragged to the shore transfer point by the tugboat, the dewatered bottom mud is transferred to the sealed tank truck for external transportation and disposal by using hoisting equipment, after cleaning the residual mud residue in the mud collecting tank 102 and checking the state of each mechanism part, the device is dragged back to the non-working river section, the layered stripping, suspended interception, mud water separation and transportation process is repeated, until the layered desilting of the target river is completed, and the whole process realizes the closed loop of "stripping-collection-separation-transportation", which takes into account the operation efficiency and ecological protection, avoids disturbance of the bottom layer inert mud and secondary pollution of the water body.

[0043] In summary: the closed loop operation of "supporting and stabilizing-layered stripping-suspended interception-mud water separation-bottom mud collection" is realized, which not only ensures the accuracy of layered desilting, but also avoids disturbance of the bottom layer inert mud and secondary pollution of the water body, and the low noise design meets the operation requirements of residential areas, significantly improves the desilting efficiency and reduces the disposal cost.

[0044] The parts not involved in the present application are the same as or can be realized by the prior art. Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A hydraulic stripping and silt reduction device for stratified sediment in urban river channels, characterized in that, include: Two sets of floating platforms (1) are provided, and a first electric push rod (106) is rotatably installed at both ends of the upper surface of each set of floating platforms (1). The piston rods of the four sets of first electric push rods (106) are rotatably installed at the four corners of the lower surface of the mounting platform (101). Connecting arms (107) are also rotatably installed at both ends of the upper surface of each set of floating platforms (1). The other end of each pair of connecting arms (107) arranged opposite to each other is rotatably installed at the middle section of both ends of the lower surface of the mounting platform (101). A U-shaped rod (104) is fixedly installed on one end of the upper surface of the mounting platform (101). A mud-sweeping mechanism (2) is rotatably installed between the two ends of the outer surface of the U-shaped rod (104). The mud-sweeping mechanism (2) can realize the action of probing into different depths in the river channel by rotating the outer surface of the U-shaped rod (104).

2. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 1, characterized in that: A conical cylinder (113) is fixedly installed on the lower surface of the mounting platform (101). A convex frame (109) is rotatably installed on both sides of the lower surface of the conical cylinder (113). A hydraulic stripping mechanism (3) is retractably installed inside the convex frame (109). A connecting rod (117) is fixedly installed at one end of the outer surface of the convex frame (109). The connecting rod (117) is rotatably connected to the piston rod of the second electric push rod (115). The other end of the second electric push rod (115) is rotatably installed on the mounting platform (101). One end of the mounting platform (101); the second electric push rod (115) can pull back the connecting rod (117) through its piston rod, causing the convex frame (109) to rotate downward around the rotation connection point with the conical cylinder (113); through the rotation of the convex frame (109), it can drive the internal hydraulic stripping mechanism (3) to adjust the tilt angle of probing into the river channel, and make the hydraulic stripping mechanism (3) extend to the river bottom at this angle, and the upper surface of the mounting platform (101) is fixedly installed with a tow hook (103).

3. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 2, characterized in that: The lower surface of the conical cylinder (113) is connected to a conveying pipe (110), which is located between the two sets of convex frames (109). The other end of the conveying pipe (110) is connected to an L-shaped pipe (111), which passes through the triangular guide plate (108) and its bent part is perpendicular to the sludge collection chamber (102). The sludge collection chamber (102) is fixedly installed on the upper surface of the mounting platform (101), and the triangular guide plate (108) is also fixedly installed on the upper surface of the mounting platform (101). A filter screen (112) is connected to the outer surface of the L-shaped pipe (111) that passes through the upper part of the inclined sliding surface of the triangular guide plate (108).

4. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 3, characterized in that: One end of the conveying pipe (110) is fixedly installed with a sealing pipe (118), and a first motor (114) is fixedly installed inside the sealing pipe (118). The output shaft of the first motor (114) passes through the conveying pipe (110) through a sealed bearing, and a spiral conveying blade (120) is fixedly installed on the outer surface of the output shaft. The spiral conveying blade (120) can rotate under the drive of the first motor (114) to push the mud into the L-shaped pipe (111) and convey it upward in the vertical direction. When the mud is conveyed to the location of the filter screen (112), the water in the mud can be filtered out by the filter screen (112) under the action of natural gravity. One end of the outer surface of the conical cylinder (113) is connected to a receiving hopper (119), and the receiving hopper (119) is perpendicular to the discharge end of the sludge sweeping mechanism (2).

5. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 4, characterized in that: The sludge sweeping mechanism (2) includes two sets of square plates (208), both sets of square plates (208) are rotatably mounted on both ends of the outer surface of the U-shaped rod (104); a connecting plate (201) is fixedly mounted on one end of the outer surface of each set of square plates (208), and two sets of transmission columns (202) are rotatably mounted between the two sets of connecting plates (201); a conveyor belt (203) is fitted on the outer surface of the two sets of transmission columns (202), and multiple sets of sludge-collecting nets (204) are fixedly mounted on the outer surface of the conveyor belt (203) at equal intervals.

6. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 5, characterized in that: One end of the square plate (208) is embedded with a second motor (206); the output shaft of the second motor (206) and one end of one of the transmission columns (202) are both fixedly mounted with transmission discs (205), and the outer surfaces of the two sets of transmission discs (205) are fitted with synchronous belts; the second motor (206) can drive the transmission column (202) to rotate through the synchronous belt, and the rotating transmission column (202) can drive the conveyor belt (203) fitted on its outer surface to run, thereby causing the conveyor belt (203) to drive the mud-collecting net (204) to collect the suspended bottom mud in the river and discharge it into the receiving bucket (119).

7. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 6, characterized in that: One end of the inner side of the connecting plate (201) is rotatably connected to the piston rod of the third electric push rod (207). The third electric push rod (207) is rotatably mounted on one end of the upper surface of the mounting platform (101). The third electric push rod (207) can push the connecting plate (201) through its piston rod, so that the connecting plate (201) drives the conveyor belt (203) and the mud-collecting net (204) to adjust their angle through the square plate (208), and adjust the mud-collecting net (204) to reach the depth of the mud-collecting net in the river channel.

8. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 7, characterized in that: The hydraulic stripping mechanism (3) includes two sets of scissor arms (301), the tail ends of the two sets of scissor arms (301) are rotatably installed in the convex frame (109); the upper and lower surfaces of the pivot hinged at the center of the scissor arms (301) are respectively fixedly installed with slip rings (305) and locking rings (302); the slip rings (305) are slidably installed in the mounting cavity (105) through the slide bar opening (116), the mounting cavity (105) is opened in the upper half of the convex frame (109), and the slide bar opening (116) is opened on the inner upper surface of the mounting cavity (105); a fourth electric push rod (306) is fixedly installed at one end of the mounting cavity (105), and the piston rod of the fourth electric push rod (306) is rotatably connected to one of the slip rings (305) that slide through into the mounting cavity (105).

9. The urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 8, characterized in that: A corrugated pipe (303) is fixedly installed inside the locking ring (302), and a high-pressure nozzle (304) is installed between one end of the two sets of corrugated pipes (303); the other end of the corrugated pipe (303) is set through one end of the convex frame (109), and this end can be connected to the outlet of the external water pump; the inlet of the external water pump can be directly put into the river to draw river water from the river.

10. A method for hydraulic stripping and silt reduction of urban riverbed sediment based on the urban riverbed sediment layering hydraulic stripping and silt reduction device according to claim 9, characterized in that, Includes the following steps: S1. Before carrying out sediment reduction operations on the target river channel, survey points are set up every 50m along the longitudinal direction of the target river channel and in the left-center-right direction in the transverse direction. A 1.5m columnar sampler is used to collect sediment samples from each survey point. S2. In the laboratory, the particle size distribution of the sediment samples was analyzed by sieving to determine that the surface sediment was floating mud with a particle size <0.05mm, the middle sediment was transition mud with a particle size of 0.05-0.1mm, and the bottom sediment was inert sand with a particle size >0.1mm. The COD concentration, TP concentration and moisture content of the surface sediment, middle sediment and bottom sediment were measured simultaneously to clarify the thickness boundaries and physicochemical properties of the three sediment layers. S3. Based on the stratification characteristics of the three-layer bottom sediment, match the operating parameters of the urban river bottom sediment stratification hydraulic stripping and silt reduction device, and connect the device to the tow hook (103) of the device through a tugboat or shore towing equipment, and tow the device to the working area of ​​the target river. S4. The four sets of first electric push rods (106) of the control device extend and retract to adjust the level and height of the mounting platform (101) of the device relative to the floating platform (1), so that the device can maintain a stable working posture on the complex water surface of the river. S5. The second electric push rod (115) of the control device extends and retracts, and the piston rod of the second electric push rod (115) pushes the connecting rod (117), which drives the convex frame (109) and its internal hydraulic stripping mechanism (3) to rotate around the hinge point between the convex frame (109) and the conical cylinder (113), and adjusts the high pressure nozzle (304) of the hydraulic stripping mechanism (3) to the preset working angle and depth with the riverbed; S6. Start the water pump connected to the bellows (303) of the hydraulic stripping mechanism (3). The water pump draws river water from the river channel and pressurizes the river water to form a high-speed water flow and delivers it to the high-pressure nozzle (304). S7. The fourth electric push rod (306) of the control device extends and retracts, driving the scissor telescopic arm (301) to expand or retract within the convex frame (109), adjusting the distance between the high-pressure nozzle (304) and the riverbed surface and the spray coverage area. S8. By controlling the output pressure of the water pump, the distance between the high-pressure nozzle (304) and the riverbed surface and the travel speed of the device, the high-speed water flow ejected by the high-pressure nozzle (304) is used to precisely, layered and controllably impact and strip the bottom mud of the riverbed, so as to avoid excessive disturbance to the bottom inert sand and mud. S9. After the surface mud stripping is completed, the third electric push rod (207) of the control device extends and retracts, pushing the mud sweeping mechanism (2) to rotate around the U-shaped rod (104), and adjusting the conveyor belt (203) and mud scooping net (204) of the mud sweeping mechanism (2) to the preset scooping depth. S10. Start the second motor (206) of the sludge sweeping mechanism (2), drive the transmission column (202) to rotate through the synchronous belt, and then drive the conveyor belt (203) to run; S11. The mud scooping net (204) is used to scoop up the suspended bottom mud and the original suspended pollutants in the river channel due to hydraulic stripping. After the mud scooping net (204) is lifted to the preset height by the conveyor belt (203), the scooped bottom mud and suspended pollutants are thrown into the receiving bucket (119). The bottom mud and suspended pollutants fall into the conical cylinder (113) along the receiving bucket (119), completing the preliminary collection of surface suspended matter. S12. The suspended mud-water mixture formed after being stripped by the high-pressure nozzle (304) enters the conveying pipe (110) under the collection and guidance of the conical cylinder (113). S13. The first motor (114) of the starting device drives the spiral conveying blade (120) in the conveying pipe (110) to rotate, pushing the high-concentration mud mixture in the conveying pipe (110) upward to the location of the L-shaped pipe (111) and the filter screen (112); S14. During the vertical transport of the mud mixture along the L-shaped pipe (111), some of the water inside is separated by pressure filtration through the filter screen (112) under the action of gravity, and the separated water flows back to the river channel. S15. The bottom sediment that has been initially dewatered continues to be transported along the L-shaped pipe (111) to the sediment collection chamber (102) for temporary storage, or transported to subsequent treatment equipment through an external pipeline to complete the sediment reduction operation of the riverbed.

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