Geotextile Tube Dewatering System for High-Moisture-Content Slurry and Its Dewatering Method

Abstract

The present invention discloses a geotextile tube bag dehydration system for high water content slurry and its dehydration method, belonging to the technical field of rapid dehydration of high water content slurry; it solves the technical problem of poor dehydration effect of existing geotextile tube bag devices. The geotextile tube bag dehydration system of the present invention includes a geotextile tube bag dehydration device; the geotextile tube bag dehydration device includes a geotextile tube bag body, a drainage unit and a vacuum pumping unit; the drainage unit includes a process drainage structure and a later-stage drainage structure; the vacuum pumping unit is arranged outside the geotextile tube bag body, and the vacuum pumping unit is connected to the process drainage structure. The vacuum pumping unit is used to pump vacuum on the process drainage structure to remove the water in the geotextile tube bag body; when the vacuum gauge reading of the vacuum pumping unit remains unchanged, insert the later-stage drainage structure into the geotextile tube bag body, and use the later-stage drainage structure to further dehydrate the high water content slurry in the geotextile tube bag. The present invention realizes the rapid dehydration of high water content slurry.

Description

Technical Field

[0001] The present invention relates to the technical field of rapid dehydration of high water content slurry, and particularly to a geotextile tube bag dehydration system for high water content slurry and a dehydration method thereof. Background Art

[0002] A large amount of waste high water content slurry is generated in the treatment of rivers, lakes and reservoirs and the dredging project of port waterways. It is statistically shown that billions of cubic meters of high water content slurry are generated in China every year, and the problem of rapid dehydration of such high water content slurry still remains a major problem troubling the engineering field.

[0003] High water content slurry is mainly composed of fine soil particles, with the clay particle content usually greater than 20%, and usually contains substances such as organic matter and heavy metals. In China, environmental protection cutter suction dredgers are mostly used for dredging, and hydraulic flushing is mostly used for small rivers. The common feature of these two commonly used construction methods is that they will produce low-concentration, high water content dredging slurry, with a concentration of less than 20% and a water content usually higher than 200%. Dredging slurry essentially belongs to high water content solid waste, and has characteristics such as high water content, high compressibility, low shear and compressive strength.

[0004] Currently, the technologies for rapid dehydration of high water content slurry mainly include flocculation dehydration, mechanical dehydration (mainly centrifuge dehydration, plate and frame filter press dehydration, belt filter press dehydration), geotextile tube bags, electroosmosis method, etc. When these methods are used alone, the dehydration effect is poor and there are some deficiencies.

[0005] These large-volume high water content slurries are generally filled into the storage yard. Due to the disadvantages such as poor natural settlement performance of high water content slurry and long sediment-water separation cycle, it leads to a large amount of long-term land occupation and possible secondary environmental pollution. The water content of the silt after natural dehydration in the short term is relatively high, which also makes it difficult to be directly applied in engineering. Therefore, how to quickly separate the mud and water in the short term and realize the rapid turnover of the storage yard has become an urgent problem to be solved.

[0006] When the traditional vacuum preloading method faces the situation of high clay particle content in the slurry, the particles are relatively fine and will be quickly blocked during vacuum drainage, resulting in very poor drainage effect of high water content slurry.

[0007] Mechanical dehydration is an important means to realize solid-liquid separation. Commonly used ones are belt type, centrifugal type and plate and frame filter press dehydration equipment. Due to the high clay content in the slurry and very poor hydraulic permeability, the traditional mechanical dehydration method has the situations of high energy consumption, large investment, relatively complex operation management, and small one-time slurry treatment capacity.

[0008] The electroosmosis technology has high energy consumption, great technical difficulty and high construction cost. At present, the research on the electroosmosis method focuses on the theoretical and experimental research stage and has not been widely applied in actual projects.

[0009] As a relatively low-cost synthetic material, geosynthetics have good water permeability and sewage interception performance, and have been widely used in dike projects, reclamation projects, and slope protection projects. They are playing an increasingly important role in various geotechnical engineering constructions. Summary of the Invention

[0010] In view of the above analysis, the present invention aims to provide a geotube dewatering system for high water content slurry and its dewatering method to solve the technical problem of poor dewatering effect of existing geotube devices.

[0011] The object of the present invention is mainly achieved through the following technical solutions:

[0012] On the one hand, the present invention provides a geotube dewatering system for high water content slurry. The geotube dewatering system includes a geotube dewatering device; the geotube dewatering device includes a geotube body, a drainage unit, and a vacuum pumping unit;

[0013] The drainage unit includes a process drainage structure and a later-stage drainage structure; the vacuum pumping unit is arranged outside the geotube body, and the vacuum pumping unit is connected to the process drainage structure. The vacuum pumping unit is used to pump vacuum on the process drainage structure to remove the water in the geotube body; when the vacuum gauge reading of the vacuum pumping unit remains unchanged, insert the later-stage drainage structure into the geotube body, and use the later-stage drainage structure to further dehydrate the high water content slurry in the geotube.

[0014] In a possible design, the process drainage structure includes a plurality of three-dimensional drainage board nets arranged parallel to each other and along the length direction of the geotube body.

[0015] In a possible design, the three-dimensional drainage board net includes an inner drainage board net and an outer drainage board net; the outer drainage board net is sleeved outside the inner drainage board net, and the two are coaxially arranged;

[0016] The inner drainage board net is connected to the vacuum pumping unit, and the outer drainage board net is connected to the motor. The vacuum pumping unit can pump vacuum on the three-dimensional drainage board net; the motor can drive the outer drainage board to rotate and thus generate relative rotation with the inner drainage board net.

[0017] In a possible design, the gap between the inner wall of the outer drainage board net and the outer wall of the inner drainage board net is 1-2 mm.

[0018] In a possible design, the three-dimensional drainage board net is long and round tubular; one end of the three-dimensional drainage board net is the vacuum device interface end, and the other end is the closed end; the vacuum device interface end is arranged outside the geotube body; the closed end is arranged inside the geotube body;

[0019] A motor connector is provided at the closed end, and the motor connector is located outside the geotextile tube bag body; the output end of the motor is connected to the outer drainage plate mesh through the motor connector, and the motor is used to drive the outer drainage plate mesh to rotate to generate relative rotation with the inner drainage plate mesh.

[0020] In a possible design, the later drainage structure includes a plurality of rigid diversion columns with the same structure; when the vacuum gauge reading remains unchanged, insert the plurality of rigid diversion columns into the geotextile tube bag body vertically from the top of the geotextile tube bag body.

[0021] A wedge-shaped diversion opening is provided at the bottom of the rigid diversion column; a plurality of diversion grooves are provided on the rigid diversion column; the water in the high water content slurry flows downward along the diversion grooves to the bottom of the rigid diversion column.

[0022] In a possible design, the rigid diversion column includes a fastening section and a diversion section from top to bottom; the diversion grooves are provided on the diversion section.

[0023] In a possible design, the diversion grooves are vertical diversion grooves; the vertical diversion grooves are evenly arranged along the circumference of the diversion section, and adjacent vertical diversion grooves are parallel to each other; the vertical diversion grooves extend downward to the wedge-shaped diversion opening; the vertical diversion grooves communicate with the inner cavity of the diversion section.

[0024] On the other hand, the present invention also provides a method for dehydrating a geotextile tube bag of high water content slurry, using the above-mentioned geotextile tube bag dehydration system for high water content slurry to perform dehydration; the method for dehydrating the geotextile tube bag includes the following steps:

[0025] Step 1: Pretreat the high water content slurry using a slurry pretreatment device.

[0026] Step 2: Use a slurry conveying device to convey the flocculated high water content slurry to the geotextile tube bag dehydration device.

[0027] Step 3: Use the geotextile tube bag dehydration device to dehydrate the high water content slurry.

[0028] Further, in Step 3, first use the process drainage structure to dehydrate the high water content slurry in the geotextile tube bag body; when the vacuum gauge reading remains unchanged, use the later drainage structure to dehydrate the high water content slurry in the geotextile tube bag body.

[0029] Compared with the prior art, the present invention can at least achieve one of the following beneficial effects:

[0030] (1) The present invention first uses the process drainage structure to dehydrate the high water content slurry in the geotextile tube bag body, and when the vacuum gauge reading remains unchanged, then uses the later drainage structure to further dehydrate the high water content slurry in the geotextile tube bag body. By dehydrating the high water content slurry in stages, it ensures that the dehydration of the high water content slurry is relatively thorough and efficient.

[0031] (2) By providing a multi-layer three-dimensional drainage plate network and evacuating it through a vacuum pumping unit, a large number of mesh holes on the three-dimensional drainage plate network can form a large number of drainage channels, reducing the penetration path of water in the high moisture content mud, thereby reducing the penetration time and improving the dehydration efficiency.

[0032] (3) By providing an inner drainage plate network and an outer drainage plate network, the vacuum pumping unit is connected to the inner drainage plate network to evacuate the geotextile tube bag, and the outer drainage plate network is connected to the motor. The motor can drive it to rotate to clean the mud particles adhered to its surface, preventing it from blocking the mesh holes on the three-dimensional drainage plate network and affecting the dehydration efficiency.

[0033] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification, and some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained from the content specifically pointed out in the embodiments of the specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings are only for the purpose of showing specific embodiments and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs represent the same components.

[0035] Figure 1 is a schematic structural view of a geotextile tube bag dehydration device Figure 1 ;

[0036] Figure 2 is a schematic structural view of a geotextile tube bag dehydration device Figure 2 ;

[0037] Figure 3 is a schematic structural view of a horizontal well-shaped groove at the bottom of the geotextile tube bag body;

[0038] Figure 4 is a schematic structural view of the top of the geotextile tube bag body;

[0039] Figure 5 is a side view of the geotextile tube bag dehydration device;

[0040] Figure 6 is a schematic structural view of a rigid guide post;

[0041] Figure 7 is a schematic structural view of a three-dimensional drainage plate network;

[0042] Figure 8 is a schematic structural view of a conveying pipeline.

[0043] Reference Signs:

[0044] 1-geotube bag body; 2-vacuum pump; 3-vacuum tube; 4-three-dimensional drainage board net; 401-outer drainage board net; 402-inner drainage board net; 403-motor; 5-horizontal well-shaped groove; 6-zipper structure; 7-rigid diversion column; 701-fastening section; 702-diversion section; 703-wedge-shaped diversion port; 704-support column; 705-diversion shell; 706-diversion cavity; 8-vertical diversion groove; 9-cuff; 10-conveying pipeline; 11-front spoiler; 12-agitator; 13-rear spoiler; 14-rectangular serrated groove. DETAILED DESCRIPTION

[0045] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0046] The present invention provides a geotube dewatering system for high-water content slurry, such as Figure 1 and Figure 5 As shown, the geotube dewatering system includes a geotube dewatering device; wherein, the geotube dewatering device includes a geotube body 1, a drainage unit and a vacuum unit; the drainage unit includes a process drainage structure and a post-drainage structure; the vacuum unit is arranged outside the geotube body 1, the vacuum unit is connected to the process drainage structure, and the vacuum unit is used to vacuum the process drainage structure to remove moisture from the geotube body 1; when the vacuum indication number of the vacuum unit remains unchanged, the post-drainage structure is inserted into the geotube body 1, and the high-water content mud in the geotube is further dehydrated by the post-drainage structure.

[0047] Specifically, the geotube dewatering device includes a geotube body 1, a drainage unit and a vacuum unit; the drainage unit includes a process drainage structure and a later drainage structure, wherein the process drainage structure needs to be pre-buried in the geotube body 1; the process drainage structure is connected to the vacuum unit; after the geotube body 1 is filled with high-water content mud, the geotube dewatering system of the present invention first uses the gravity of the high-water content mud itself to drain the water, and then turns on the vacuum unit, and uses the vacuum unit to vacuum the process drainage structure to discharge the moisture in the high-water content mud; after the indication of the vacuum gauge in the vacuum unit remains unchanged, the vacuum unit is turned off; the later drainage structure is inserted into the geotube body 1 from the top of the geotube body 1 using an operating device (such as a pile driver), and the high-water content mud in the geotube body 1 is further dehydrated using the later drainage structure.

[0048] Compared with the prior art, the present invention first dehydrates the high moisture content slurry in the geotextile tube body 1 by using the process drainage structure. When the vacuum gauge reading remains unchanged, the later drainage structure is used to further dehydrate the high moisture content slurry in the geotextile tube body 1. By dehydrating the high moisture content slurry in stages, it is ensured that the dehydration of the high moisture content slurry is relatively thorough and efficient.

[0049] It should be noted that a geotextile membrane is sealed on the outer surface of the geotextile tube body 1 of the present invention. The geotextile membrane and the geotextile tube are tightly wrapped to form a sealed whole, ensuring that the vacuum can be effectively transmitted to improve the airtightness of the entire geotextile dehydration device.

[0050] In order to achieve rapid dehydration of the high moisture content slurry, the process drainage structure of the present invention includes a plurality of three-dimensional drainage plate meshes 4 arranged in parallel and along the length direction of the geotextile tube body. The setting spacing between adjacent three-dimensional drainage plate meshes 4 is 0.7 - 1.5 m.

[0051] Compared with the prior art, the present invention sets a plurality of three-dimensional drainage plate meshes 4 and evacuates them through the vacuum pumping unit. A large number of mesh holes on the three-dimensional drainage plate mesh 4 can form a large number of drainage channels, reducing the penetration path of water in the high moisture content slurry, thereby reducing the penetration time and improving the dehydration efficiency.

[0052] The material of the three-dimensional drainage plate mesh 4 of the present invention is selected as biodegradable polylactic acid fiber.

[0053] It should be noted that the vacuum pumping unit of the present invention includes a vacuum pump 2 and a vacuum tube 3. The vacuum pump 2, the vacuum tube 3 and the three-dimensional drainage plate mesh 4 are connected in sequence. The vacuum pump 2 evacuates the three-dimensional drainage plate mesh 4 through the vacuum tube 3 to generate negative pressure in the geotextile tube body 1, thereby accelerating the discharge of water in the high moisture content slurry and air in the geotextile tube body 1.

[0054] To prevent the slurry particles from blocking the surface of the three-dimensional drainage plate mesh 4 during the vacuum pumping process and causing a reduction in the vacuum degree, as Figure 7 shown, the three-dimensional drainage plate mesh 4 of the present invention is in a long circular tube shape, which includes an inner drainage plate mesh and an outer drainage plate mesh; the outer drainage plate mesh is sleeved outside the inner drainage plate mesh, and the two are coaxially arranged; the inner drainage plate mesh is connected to the vacuum pumping unit, and the outer drainage plate mesh is connected to the motor. The vacuum pumping unit can evacuate the three-dimensional drainage plate mesh 4; the motor can drive the outer drainage plate to rotate relative to the inner drainage plate mesh.

[0055] Specifically, after using the three-dimensional drainage plate mesh 4 to dehydrate the high moisture content slurry for a period of time, the slurry particles in the high moisture content slurry are likely to adhere to the surface of the three-dimensional drainage plate mesh 4. At this time, the motor is used to drive the outer drainage plate to rotate, and the outer drainage plate mesh can rotate relative to the adhered slurry particles on its surface and thus be cleaned off.

[0056] Compared with the prior art, in the present invention, an inner drainage mesh plate and an outer drainage mesh plate are provided. The vacuum pumping unit is connected to the inner drainage mesh plate to vacuum the geotextile tube bag. The outer drainage mesh plate is connected to the motor, and the motor can drive it to rotate, thereby cleaning the mud particles adhering to its surface and preventing it from blocking the mesh holes on the three-dimensional drainage mesh plate 4 and affecting the dehydration efficiency.

[0057] It should be noted that the inner drainage mesh plate of the present invention is provided with transverse diversion grooves, and the number of the transverse diversion grooves is multiple; the transverse diversion grooves are arranged along the axial direction of the inner drainage mesh plate.

[0058] Compared with the prior art, in the present invention, by arranging transverse diversion grooves on the inner drainage mesh plate, after the geotextile tube bag body 1 is filled with high-water-content mud, the transverse diversion grooves can accelerate the speed of water entering the inner drainage mesh plate from the outer drainage mesh plate, thereby accelerating the dehydration rate of the high-water-content mud in the geotextile tube bag body 1.

[0059] It should be pointed out that when the motor drives the outer drainage mesh plate to rotate, in order to ensure that the outer drainage mesh plate and the inner drainage mesh plate rotate relative to each other and ensure that there is no friction with the outer surface of the inner drainage mesh plate, there is a certain gap between the inner wall of the outer drainage mesh plate and the outer wall of the inner drainage mesh plate of the present invention; the size of the gap is 1-2 mm.

[0060] In order to better drive the outer drainage mesh plate to rotate, as Figure 7 shown, one end of the three-dimensional drainage mesh plate 4 of the present invention is a vacuum device interface end, and the other end is a closed end; the vacuum device interface end is arranged outside the geotextile tube bag body 1; the closed end is arranged inside the geotextile tube bag body 1; a motor connector is provided at the closed end, and the motor connector is located outside the geotextile tube bag body 1; the output end of the motor is connected to the outer drainage mesh plate through the motor connector for driving the outer drainage mesh plate to rotate to generate relative rotation with the inner drainage mesh plate.

[0061] Specifically, the three-dimensional drainage mesh plate 4 of the present invention is integrally long and round tubular, that is, both the inner drainage mesh plate and the outer drainage mesh plate are long and round tubular; the vacuum device interface end is arranged outside the geotextile tube bag body 1, the vacuum device interface end is connected to the inner drainage mesh plate, and the vacuum pump 2 is fixedly connected to the vacuum device interface end through the vacuum tube 3; the motor is fixedly connected to the motor connector through the motor output end, and the motor connector is fixedly connected to the outer drainage mesh plate at the closed end.

[0062] Compared with the prior art, the inner drainage board net of the present invention is connected to the vacuum tube 3 and the vacuum pump 2 through a vacuum device joint, so as to realize vacuuming inside the geotube bag; the outer drainage board net of the present invention is connected to the output end of the motor through a motor joint, so as to ensure that the motor drives it to rotate and thereby causes it to rotate relative to the inner drainage board net and the mud particles adhering to its surface, thereby cleaning up the mud particles adhering to the surface of the outer drainage board net to avoid affecting the mud dehydration process.

[0063] It should be emphasized that in order to ensure the maximum dehydration, the mesh size of the inner drainage board net and the outer drainage board net of the present invention is O 90 is the median particle size of the slurry after flocculation 50 8-16 times of O 90 = (8-16) × d 50 , O 90 is the effective aperture of the inner and outer drainage mesh, d 50 It is the median particle size of the mud after flocculation; if the mesh size of the inner drainage board and the outer drainage board is too large, the flocs will be sucked away through the pores of the drainage board; if the mesh size of the inner drainage board and the outer drainage board is too small, the flocs will be blocked in the pores or form mud skin on the surface, hindering further vacuum preloading.

[0064] In order to further dehydrate the high-water content mud in the geotube bag body 1; the later drainage structure of the present invention includes a plurality of rigid diversion columns 7 with the same structure, such as Figure 2 As shown; after the vacuum indication number remains unchanged and the sludge in the geotube bag is consolidated for a period of time by its own gravity, open the zipper on the top of the geotube bag, and use a pile driver to insert multiple rigid guide columns 7 into the geotube bag body 1 in the vertical direction; the bottom of the rigid guide column 7 is a wedge-shaped guide port 703; the rigid guide column 7 is provided with multiple parallel guide grooves; the water in the high-water content mud enters the rigid guide column 7 through the guide groove.

[0065] Specifically, a guide column insertion point is provided on the top surface of the geotube bag body, and the guide column insertion points are arranged in the positive direction, with an insertion point set every 2 m in the horizontal and vertical directions; when it is necessary to insert the later drainage structure, the rigid guide column is sunk from the guide column insertion point into the geotube bag body by a pile driver through vibration or static pressure until the wedge-shaped guide port 703 at the bottom of the rigid guide column contacts the bottom of the geotube bag body.

[0066] Compared with the prior art, the present invention can further dehydrate the high-moisture-content slurry in the geotextile tube bag by providing the rigid diversion column 7; the material of the rigid diversion column 7 is set as a rigid material for the purpose of facilitating its insertion into the geotextile tube bag body 1; by providing a plurality of diversion grooves on the rigid diversion column, the water in the geotextile tube bag can be accelerated to enter the rigid diversion column 7; by providing the wedge-shaped diversion port 703, on the one hand, it helps to insert it into the geotextile tube bag body 1, and on the other hand, it can divert the water entering the rigid diversion groove to the bottom of the geotextile tube bag body 1 and discharge it through the drain port provided at its bottom.

[0067] In order to facilitate the insertion of the rigid diversion column 7 into the geotextile tube bag body 1 in the vertical direction, the rigid diversion column 7 of the present invention successively includes a fastening section 701 and a diversion section 702 from top to bottom; the diversion grooves are provided on the diversion section 702.

[0068] It should be noted that, as Figure 6 shown, the diversion section 702 of the rigid diversion column 7 includes a support column 704 and a cylindrical diversion outer shell 705; wherein, the cylindrical diversion outer shell 705 is sleeved outside the support column 704, and the cavity between the two forms a diversion space; the top of the support column 704 and the top of the cylindrical diversion outer shell 705 are integrally formed with the fastening section 701; the diversion grooves on the diversion outer shell 705 are vertical diversion grooves 810, and the vertical diversion grooves 810 are uniformly arranged along the circumferential direction of the diversion outer shell 705, and the vertical diversion grooves 810 are parallel to each other; the vertical diversion grooves 810 extend downward to the wedge-shaped diversion port 703; the vertical diversion grooves 810 communicate with the diversion cavity 706 of the diversion section 702.

[0069] It should be noted that the rigid diversion column 7 of the present invention is hexagonal pyramid-shaped, and setting it as hexagonal pyramid-shaped helps to insert it into the geotextile tube bag body 1.

[0070] In order to ensure smooth drainage at the bottom of the geotextile tube bag device, a groove is provided in the filling area below the geotextile tube bag body of the present invention. As Figure 3 shown, the grooves are arranged in a horizontal cross shape, and a mixture of coarse sand and gravel is provided in the horizontal cross-shaped groove 5.

[0071] Compared with the prior art, the present invention can ensure smooth drainage at the bottom of the geotextile tube bag body by providing the horizontal cross-shaped groove 5 and providing a mixture of coarse sand and gravel in the groove.

[0072] It should be noted that in the above-mentioned mixture of coarse sand and gravel, the particle size range of the coarse sand is between 0.5 - 2 mm, the particle size range of the gravel is 60 - 200 mm, and the grading ratio of the coarse sand to the gravel is 7:3; the horizontal and vertical spacings of the horizontal cross-shaped groove 5 are both 20 cm.

[0073] It should be noted that the bottom of the rigid diversion column 7 of the present invention penetrates through the geotextile tube bag body 1, and the removed water enters the groove at the bottom of the geotextile tube bag body 1 through the wedge-shaped diversion port 703.

[0074] To facilitate the removal of the dewatered mud blocks, as Figure 4 shown, a zipper structure 6 is provided on the upper surface of the geotextile tube bag of the present invention.

[0075] Specifically, a zipper structure 6 and cuffs 9 are provided on the upper surface of the geotextile tube bag body 1; among them, the zipper structure 6 includes a plurality of zippers arranged along the length direction of the geotextile tube bag body 1 and parallel to each other, and the distance between adjacent zippers is 1 / 5 - 1 / 3 of the width of the geotextile tube bag body 1.

[0076] Compared with the prior art, by setting the zipper structure 6 on the geotextile tube bag body 1, after the high water content slurry is drained and consolidated, the zipper structure 6 above the geotextile tube bag body 1 is opened, which is convenient for taking out the harder soil blocks after dehydration.

[0077] To pre-treat the high water content slurry, the geotextile tube bag dewatering system of the present invention further includes a slurry pre-treatment device; the high water content slurry pre-treated by the slurry pre-treatment device enters the geotextile tube bag dewatering device for dewatering treatment.

[0078] Compared with the prior art, the present invention can pre-treat the high water content slurry through the slurry pre-treatment device, making it accumulate into a group, which is convenient for subsequent dehydration.

[0079] To enable the high water content slurry to better accumulate into a group, the pre-treatment device of the present invention includes a sedimentation tank and an adjustment tank; a flocculation mixer and a flocculant dosing pump are provided on the adjustment tank; among them, the high water content slurry dug by a dredger first enters the sedimentation tank for sedimentation, then enters the adjustment tank, and then a compound flocculant is added to it by using the flocculant dosing pump, and at the same time, the flocculation mixer is turned on for stirring.

[0080] It should be pointed out that the high water content slurry, which is the treatment object of the geotextile tube bag dewatering device of the present invention, mainly includes dredging slurry and engineering slurry; the flocculant material used is a compound flocculant of chitosan (CS) - anionic polyacrylamide (APAM) - calcium chloride (CaCl2); the compound flocculant of chitosan (CS) - anionic polyacrylamide (APAM) - calcium chloride (CaCl2) can reduce the surface potential of clay particles, compress the double electric layer and play the role of adsorption bridging, so that the particles change from a stable state to an unstable state, and the particles aggregate into a group.

[0081] Compared with the prior art, through the above compound flocculant, the present invention enables the high water content mud to accumulate into a mass under the flocculation effect, and it is not easy to block the three-dimensional drainage board network 4 and the rigid diversion column 7 during the drainage process, ultimately accelerating the drainage consolidation rate inside the geotextile tube bag, which is of great significance for environmental protection, pollution prevention and control, resource utilization of solid waste, and sustainable development in China.

[0082] In order to convey the pretreated high water content mud, the geotextile tube bag dewatering system of the present invention further includes a mud conveying device; the mud conveying device is used to convey the flocculation-treated high water content mud into the geotextile tube bag dewatering device.

[0083] Compared with the prior art, through the mud conveying device, the present invention can convey the high water content mud into the geotextile tube bag dewatering device for dewatering treatment.

[0084] When conveying the pretreated high water content mud, to avoid its settlement, the mud conveying device of the present invention includes a conveying pipeline 10 and a mixing component; the mixing component is arranged inside the conveying pipeline 10; one end of the conveying pipeline 10 is connected to the mud pretreatment device, and the other end is connected to the geotextile tube bag dewatering device, and it is used to convey the flocculation-pretreated high water content mud into the geotextile tube body 1.

[0085] Compared with the prior art, by adding a mixing component, the present invention can further stir the mixed liquid of the high water content mud and the flocculant inside the conveying pipeline 10, making the two mix more evenly.

[0086] To further improve the uniformity of the mixing of the flocculant and the high water content mud, as Figure 8 shown, the mixing component of the present invention includes a front spoiler 11, a stirrer 12, and a rear spoiler 13; wherein, the front spoiler 11 is arranged in front of the stirrer 12, and the rear spoiler 13 is arranged behind the stirrer 12, and both are fixed on the inner wall of the conveying pipeline 10.

[0087] Compared with the prior art, by arranging a stirrer 12 on the inner wall of the conveying pipeline 10, the present invention can accelerate the further mixing of the high water content mud and the flocculant; by arranging a front spoiler 11 and a rear spoiler 13 inside the conveying pipeline 10, not only can the flow rate of the mixed liquid of the high water content mud and the flocculant be reduced, but also the mixing of the high water content mud and the flocculant can be promoted.

[0088] It should be noted that, as Figure 8As shown in the figure, the front spoiler 11 and the rear spoiler 13 of the present invention have the same structure. Both are composed of 2-3 hollow frustum-shaped spoilers arranged in parallel; the hollow frustum-shaped spoilers are arranged at equal intervals along the axial direction of the conveying pipeline 10; one end of the hollow frustum-shaped spoiler is the large end of the frustum, and the other end is the small end of the frustum. Among them, the outer diameter of the large end of the frustum is the same as the inner diameter of the conveying pipeline 10, and the hollow frustum-shaped spoiler is welded to the inner wall of the conveying pipeline 10 through its large end; the small end of the frustum faces the inflow direction of the high water content mud, and a rectangular serrated groove 14 is provided along the circumference of the small end of the frustum.

[0089] Compared with the prior art, by setting a plurality of hollow frustum-shaped spoilers, the present invention can reduce the flow rate of the high water content mud and flocculant mixture, and at the same time further strengthen the mixing degree of the high water content mud and the flocculant, so that the high water content mud can better agglomerate into groups.

[0090] On the other hand, the present invention also provides a method for dehydrating high water content mud in a geotextile tube bag, using the above-mentioned geotextile tube bag dehydration system for high water content mud to carry out dehydration; specifically including the following steps:

[0091] Step 1: Pretreat the high water content mud by using a mud pretreatment device; specifically including the following sub-steps:

[0092] Step 11: Use an environmental protection cutter suction dredger for construction operations;

[0093] Step 12: The dredged sludge (high water content mud) dug by the dredger first enters the sedimentation tank for sedimentation;

[0094] Step 13: Pump the high water content mud in the upper layer of the sedimentation tank to the adjustment tank, and use a mechanical stirrer to stir to mix the sludge and the flocculant solution. The stirring time is 3 min - 5 min.

[0095] In the above step 13, the compound flocculant used in the present invention is: chitosan (CS) - anionic polyacrylamide (APAM) - calcium chloride (CaCl2). The incorporation sequence is: first add CS, then add APAM, and finally add CaCl2. Adding the compound flocculant strictly in the above addition sequence can obtain the best precipitation effect.

[0096] In the above compound flocculant, CS has a positive charge on its surface, and the soil particles have a negative charge on their surface. CS attracts the soil particles through charge neutralization and adsorption bridging. The molecular long chain of APAM contains polar groups, which can attract fine soil particles in the mud through adsorption bridging to form large-sized flocs, thus achieving rapid precipitation. Ca 2+ ionized by CaCl2 can further neutralize the negative charge on the surface of the soil particles.

[0097] In the above step 13, the mass concentration of the CS solution is 1.5‰ - 1.8‰, the mass concentration of the APAM solution is 0.5‰ - 1.0‰, and the mass concentration of the CaCl2 solution is 1% - 2%.

[0098] It should also be emphasized that the preparation method of the compound flocculant of the present invention is as follows: First, dissolve chitosan powder in water to form a solution, pour it into the slurry and stir for 5 - 6 minutes, and the mass concentration of the CS solution is 1.5‰ - 1.8‰; then, dissolve the APAM white solid particles in water to form a solution, the mass concentration of the APAM solution is 0.5‰ - 1.0‰, pour it into the above - mentioned mixture of chitosan and slurry, and stir for 2 - 4 minutes; finally, dissolve the CaCl2 solid particles in water to form a solution, the mass concentration of the CaCl2 solution is 1% - 2%; pour it into the above - mentioned mixture of chitosan - APAM and slurry, and stir for 2 - 3 minutes.

[0099] Compared with the existing single flocculant, the compound flocculant of the present invention can achieve a larger sedimentation volume within the same time, and the sedimentation volume is increased by 50%.

[0100] It should be noted that the dosage of each component in the compound flocculant of the present invention is calculated according to the following formula.

[0101] ;

[0102] In the formula:

[0103] Q y ― The flow rate of the added medicament, in cubic meters per hour (m 3 / h);

[0104] Q n ― The flow rate of the slurry, in cubic meters per hour (m 3 / h);

[0105] C y ― The concentration of the medicament, in kilograms per cubic meter (kg / m 3 );

[0106] C n ― The concentration of the slurry, in kilograms per cubic meter (kg / m 3 );

[0107] K ― The ratio of the mass of the medicament to the mass of dry soil in the slurry, dimensionless. The value of K is determined through experiments.

[0108] In summary, by adding a compound flocculant, the present invention can aggregate smaller clay particles into clusters. On the one hand, it makes it difficult for smaller clay particles to flow out of the pores of the geotextile tube bag. On the other hand, during vacuum pumping, the large particle mud flocculated into clusters is not easily blocked by the three-dimensional drainage plate network 4, improving the construction efficiency. The fine clay particles in the high moisture content mud begin to aggregate into clusters under the action of adsorption bridging and charge neutralization of the hydrolysis products of the flocculant. After forming larger particle clusters, they settle. During the filling process, the water in the high moisture content mud is separated out. Under the action of its own gravity, the water is separated out from the pores on the surface of the geotextile tube bag.

[0109] Step 2: Use a mud conveying device to convey the flocculation-treated high moisture content mud to the geotextile tube bag dewatering device.

[0110] The flocculation-treated high moisture content mud is conveyed to the geotextile tube bag body 1 through the conveying pipeline 10. During the conveying process, the front spoiler 11, stirrer 12 and rear spoiler 13 in the conveying pipeline 10 can mix the high moisture content mud and the compound flocculant again, further improving the mixing uniformity of the two.

[0111] Step 3: Dewater the high moisture content mud.

[0112] Step 31: First, use the process drainage structure to dewater the high moisture content mud in the geotextile tube bag body 1.

[0113] After filling the high moisture content mud into the geotextile tube bag body 1, the high moisture content mud drains first under its own gravity. Then, turn on the vacuum pump 2. The vacuum pump 2 evacuates the three-dimensional drainage plate network 4 through the vacuum tube 3 to create a negative pressure inside the geotextile tube bag body 1, thereby accelerating the discharge of the water in the high moisture content mud and the air inside the geotextile tube bag body 1.

[0114] Step 32: Use the later drainage structure to dewater the high moisture content mud in the geotextile tube bag body 1.

[0115] After the vacuum gauge reading remains unchanged and the silt in the geotextile tube consolidates by its own gravity for a period of time, the moisture content of the high moisture content mud is reduced by 50%. Turn off the vacuum pumping unit. Open the zipper at the upper part of the geotextile tube bag and use a pile driver to insert multiple rigid guide columns 7 vertically into the geotextile tube bag body 1 from the top of the geotextile tube bag body 1 by vibration or static pressure methods. Use the rigid guide columns 7 to further dewater the high moisture content mud in the geotextile tube bag body 1. After dewatering is completed, randomly take samples of the consolidated silt on the surface of the geotextile tube bag with a soil sampler and test the moisture content of the on-site samples. If the average moisture content of the samples has been reduced to less than 30%, it indicates that the dewatering is completed.

[0116] Compared with the prior art, the present invention dehydrates the high-water-content mud in stages to ensure thorough and efficient dehydration of the high-water-content mud. The water content of the soil after dehydration is reduced to 30%, which can shorten the construction period, improve the utilization rate of geotextile tubes, and enhance the land turnover efficiency.

[0117] The dehydration process using the above-mentioned geotextile tube dehydration system for high-water-content mud includes:

[0118] Step 1: Pretreat the high-water-content mud using a mud pretreatment device; specifically, it includes the following sub-steps:

[0119] Step 11: Carry out construction operations using an environmental protection cutter suction dredger;

[0120] Step 12: The dredged silt (high-water-content mud) excavated by the dredger first enters the sedimentation tank for sedimentation;

[0121] It should be noted that a wire mesh with a pore size of 1 mm is laid above the sedimentation tank to remove white garbage and large rocks in the dredged mud. The mud with impurities preliminarily removed falls into the sedimentation tank and waits for 1 h, so that the sediment sinks to the bottom under the action of its own gravity.

[0122] Step 13: Use a flocculant dosing pump to add a compound flocculant into the adjustment tank, and at the same time use a flocculation mixer to stir to mix the high-water-content mud (silt) with the compound flocculant solution; complete the pretreatment of the high-water-content mud.

[0123] It should be noted that the adjustment volume of the adjustment tank is calculated according to the following formula:

[0124] (1)

[0125] In the formula:

[0126] V - the adjustment volume of the adjustment tank, in cubic meters (m 3 )

[0127] Q0 - the mud flow rate entering previously, in cubic meters per hour (m 3 / h)

[0128] Q n - the mud flow rate for subsequent treatment, in cubic meters per hour (m 3 / h), n is a natural number; T - the interval period for stopping pumping out mud when the adjustment tank reaches the lowest liquid level or stopping entering mud when it reaches the highest liquid level, in hours (h); T is greater than or equal to 2 h.

[0129] In the dewatering site where geotextile tube bags are used for mud dewatering, if the solidified soil needs to be transported out in time and the dewatering site is to be reused, the total area of the dewatering site is divided into several work surfaces of equal area. If the number of work surfaces is determined to be n, the total area of the dewatering site required is calculated by the following formula (2):

[0130] ;

[0131] If the total area F of the dewatering site is determined, the number of work surfaces to be divided is calculated by the following formula (3):

[0132] ;

[0133] The grouting time Y1 of a single work surface is calculated by the following formula:

[0134] ;

[0135] The soil excavation time Y3 of a single work surface is calculated by the following formula:

[0136] ;

[0137] In the formula:

[0138] F ― The total area of the dewatering site, in square meters (m 2 );

[0139] n ― The number of work surfaces, which is actually an integer, taking the integer part of the value calculated by formula (3) plus 1, dimensionless;

[0140] W ― The mass of dry mud processed per day, W = Q n C n T / 1000, in tons per day (t / d);

[0141] Q n ― The mud flow rate, in cubic meters per hour (m 3 / h);

[0142] C n ― The mud concentration, in kilograms per cubic meter (kg / m 3 );

[0143] T ― The daily working hours, in hours per day (h / d);

[0144] Y1 ― The grouting time required to fill all geotextile tube bags on a single work surface with mud, in days (d);

[0145] Y2 ― The water seepage and drying time between the end of grouting and soil excavation on a single work surface, in days (d), Y2 is greater than or equal to 15 d;

[0146] Y3 ― The earth excavation time required for transporting all the consolidated soil on a single working face, with the unit of day (d);

[0147] Y4 ― The idle time of a single working face, with the unit of day (d);

[0148] H ― The maximum stacking height of geotextile tube bags, with the unit of meter (m), and H is greater than or equal to 15 m;

[0149] M ― The bulk dry density of the soil in the tube bag after dehydration, with the unit of ton per cubic meter (t / m 3 )

[0150] P ― The volume of soil transported out per day, with the unit of cubic meter per day (m 3 / d).

[0151] Step 2: When transporting the high - moisture - content slurry in the regulating tank to the geotextile tube body 1, the velocity gradient G value of the mixer in the conveying pipeline 10 is greater than 600 s -1 , and the head loss of the mixer is less than or equal to 0.5 m;

[0152] Step 3: After the geotextile tube is filled to the designed height, turn on the vacuum pump 2. First, use the process drainage structure to dehydrate the high - moisture - content slurry in the geotextile tube body 1; then use the later - stage drainage structure to dehydrate the high - moisture - content slurry in the geotextile tube body 1. After the drainage consolidation is completed, unzip the zipper - type structure 6 above the geotextile tube and take out the harder soil blocks from the geotextile tube from above.

[0153] The above - mentioned is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A geotube dewatering system for high-water content slurry, characterized in that: The geotube dewatering system comprises a geotube dewatering device; the geotube dewatering device comprises a geotube body, a drainage unit, a vacuum unit, and a motor; The drainage unit includes a process drainage structure and a post-drainage structure; the vacuum unit is arranged outside the geotube body, the vacuum unit is connected to the process drainage structure, and the vacuum unit is used to vacuum the process drainage structure to remove the moisture in the geotube body; when the vacuum indication number of the vacuum unit remains unchanged, the post-drainage structure is inserted into the geotube body, and the high-water content mud in the geotube is further dehydrated by the post-drainage structure; The process drainage structure comprises a plurality of three-dimensional drainage panels which are parallel to each other and arranged along the length direction of the geotube bag body; the three-dimensional drainage panels comprise an inner drainage panel and an outer drainage panel; the outer drainage panel is sleeved outside the inner drainage panel, and the two are coaxially arranged; The inner drainage board net is connected to the vacuum unit, and the outer drainage board net is connected to the motor. The vacuum unit can vacuum the three-dimensional drainage board net; the motor can drive the outer drainage board to rotate and then rotate relative to the inner drainage board net; The inner drainage board net is provided with a transverse guide groove, and the transverse guide groove is arranged along the axial direction of the inner drainage board net; The post-drainage structure includes a rigid guide column, which is in the shape of a hexagonal pyramid; A filling area below the geotube bag body is provided with grooves, which are arranged in a horizontal well shape.

2. The geotube dewatering system for high-water content slurry according to claim 1 is characterized in that: The gap between the inner wall of the outer drainage board net and the outer wall of the inner drainage board net is 1-2mm.

3. The geotube dewatering system for high-water content slurry according to claim 1, characterized in that: The three-dimensional drainage board net is in the shape of an oblong tube; one end of the three-dimensional drainage board net is a vacuum device interface end, and the other end is a closed end; the vacuum device interface end is arranged outside the geotextile tube bag body; the closed end is arranged inside the geotextile tube bag body; A motor connector is provided at the closed end, and the motor connector is located outside the geotube bag body; the output end of the motor is connected to the outer drainage mesh through the motor connector, and the motor is used to drive the outer drainage mesh to rotate so as to generate relative rotation with the inner drainage mesh.

4. The geotube dewatering system for high-water content slurry according to claim 1, characterized in that: The post-drainage structure comprises a plurality of rigid guide columns with the same structure; when the vacuum indication value remains unchanged, the plurality of rigid guide columns are inserted into the geotube body from the top of the geotube body in the vertical direction; A wedge-shaped guide port is provided at the bottom of the rigid guide column; a plurality of guide grooves are provided on the rigid guide column; water in the high-water content mud flows downward along the guide grooves to the bottom of the rigid guide column.

5. The geotube dewatering system for high-water content slurry according to claim 4, characterized in that: The rigid guide column comprises a fastening section and a guide section from top to bottom; the guide groove is arranged on the guide section.

6. The geotube dewatering system for high-water content slurry according to claim 5, characterized in that: The guide groove is a vertical guide groove; the vertical guide grooves are evenly arranged along the circumference of the guide section, and adjacent vertical guide grooves are parallel to each other; the vertical guide grooves extend downward to the wedge-shaped guide port; the vertical guide grooves are connected to the inner cavity of the guide section.

7. A method for dehydrating geotube bags of high-water content slurry, characterized in that: Dehydration is performed using the geotube bag dehydration system for high-water-content slurry according to any one of claims 1 to 6; the geotube bag dehydration method for high-water-content slurry comprises the following steps: Step 1: pretreating the high water content mud using a mud pretreatment device; Step 2: using a mud conveying device to convey the high-water content mud after flocculation treatment to a geotube dewatering device; Step 3: Dewater the high-water content mud using the geotube dewatering device.

8. The method for dehydrating geotube bags of high-water content slurry according to claim 7, characterized in that: In step 3, the high-water content mud in the geotube bag body is first dehydrated by using the process drainage structure; when the vacuum indication number remains unchanged, the high-water content mud in the geotube bag body is dehydrated by using the post-drainage structure.

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