Geotextile tube bag dehydration system for high-water-content slurry and dehydration method thereof

Abstract

The invention discloses a geotextile tube bag dehydration system for high-water-content slurry and a dehydration method of the geotextile tube bag dehydration system, and belongs to the technical field of rapid dehydration of the high-water-content slurry. The technical problem that an existing geotextile tube bag device is poor in dewatering effect is solved. The geotextile tube bag dewatering system comprises a geotextile tube bag dewatering device. The geotextile tube bag dewatering device comprises a geotextile tube bag body, a drainage unit and a vacuumizing unit. The drainage unit comprises a process drainage structure and a later drainage structure; the vacuumizing unit is arranged outside the geotextile tube bag body, the vacuumizing unit is connected with the process drainage structure, and the vacuumizing unit is used for vacuumizing the process drainage structure so as to remove water in the geotextile tube bag body; and when the vacuum indication number of the vacuumizing unit is not changed, the later-stage drainage structure is inserted into the geotextile tube bag body, and the high-water-content slurry in the geotextile tube bag is further dehydrated through the later-stage drainage structure. According to the invention, rapid dehydration of high-water-content slurry is realized.

Description

Technical Field

[0001] The invention relates to the technical field of rapid dehydration of high-water-content mud, in particular to a geotube bag dehydration system and a dehydration method for high-water-content mud. Background Art

[0002] A large amount of waste high-water content mud is generated in the management of rivers, lakes and reservoirs and the dredging of ports and waterways. According to statistics, my country produces billions of cubic meters of high-water content mud every year, and the rapid dehydration of these high-water content muds is still a major problem that plagues the engineering community.

[0003] High-water content mud is mainly composed of fine soil particles, and the clay content is usually greater than 20%. It usually contains organic matter, heavy metals and other substances. In my country, dredging is mostly carried out by environmentally friendly suction dredgers, and small rivers are mostly dredged by hydraulic flushing. The common feature of these two commonly used construction methods is that they will produce low-concentration, high-water content dredged mud, with a concentration of less than 20% and a water content usually higher than 200%. Dredged mud is essentially a high-water content solid waste with characteristics such as high water content, high compressibility, and low shear and compressive strength.

[0004] At present, the technologies used for rapid dehydration of high-water content mud mainly include flocculation dehydration, mechanical dehydration (mainly centrifuge dehydration, plate and frame filter press dehydration, belt filter press dehydration), geotube bag, electroosmosis, etc. When these methods are used alone, the dehydration effect is poor and there are some shortcomings.

[0005] These large volumes of high-water content mud are generally blown into the storage yard. Due to the poor natural sedimentation performance of high-water content mud and the long mud-water separation cycle, a large amount of land is occupied for a long time and secondary pollution may be caused to the environment. The high water content of the sludge after natural dehydration in a short period of time also makes it difficult to use it directly in engineering. Therefore, how to quickly separate the mud and water in a short period of time and realize the rapid turnover of the storage yard has become an urgent problem to be solved.

[0006] When faced with a high clay content in the mud, the traditional vacuum preloading method has finer particles that will quickly become clogged during vacuum drainage, resulting in poor drainage of high-water-content mud.

[0007] Mechanical dehydration is an important means to achieve solid-liquid separation. Commonly used dehydration equipment include belt, centrifugal and plate and frame filter press dehydration equipment. Due to the high clay content of the mud and poor hydraulic permeability, the traditional mechanical dehydration method has high energy consumption, large investment, relatively complex operation and management, and the one-time mud processing volume is small.

[0008] Electroosmosis technology has high energy consumption, great technical difficulty and high construction cost. At present, the research on electroosmosis is concentrated in the theoretical and experimental research stage, and has not yet been widely used in actual projects.

[0009] Geosynthetics, as a relatively low-priced artificial synthetic material with good water permeability and pollution interception performance, have been widely used in embankment projects, land reclamation projects, and slope protection projects. They play an increasingly important role in the construction of various geotechnical projects. Summary of the invention

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

[0011] The purpose 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 mud, the geotube dewatering system comprising a geotube dewatering device; the geotube dewatering device comprises a geotube body, a drainage unit and a vacuum unit;

[0013] 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 moisture from 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.

[0014] In a possible design, the process drainage structure includes a plurality of three-dimensional drainage panels that are parallel to each other and arranged along the length direction of the geotube bag 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 device, 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 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 mesh and the outer wall of the inner drainage board mesh is 1-2 mm.

[0018] In a possible design, 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;

[0019] 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 board net through the motor connector, and the motor is used to drive the outer drainage board net to rotate so as to generate relative rotation with the inner drainage board net.

[0020] In a possible design, the later drainage structure includes a plurality of rigid diversion columns of the same structure; when the vacuum indication number remains unchanged, the plurality of rigid diversion columns are inserted into the geotube body from the top of the geotube body in a vertical direction;

[0021] 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.

[0022] In a possible design, the rigid guide column includes a fastening section and a guide section from top to bottom; and the guide groove is arranged on the guide section.

[0023] In a possible design, 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.

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

[0025] Step 1: pretreating the high water content mud using a mud pretreatment device;

[0026] Step 2: using a mud conveying device to convey the high-water content mud after flocculation treatment to a geotube dewatering device;

[0027] Step 3: Dehydrate the high-water content mud using a geotube dehydration device.

[0028] Furthermore, 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.

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

[0030] (1) The present invention first uses the process drainage structure to dehydrate the high-water content mud in the geotube bag body. When the vacuum indication number remains unchanged, the post-drainage structure is used to further dehydrate the high-water content mud in the geotube bag body. By dehydrating the high-water content mud in stages, it is ensured that the high-water content mud is dehydrated more thoroughly and efficiently.

[0031] (2) The present invention sets up a multi-layer three-dimensional drainage board net and evacuates it through a vacuum unit. The large number of mesh holes on the three-dimensional drainage board net can form a large number of drainage channels, thereby reducing the penetration path of water in high-water content mud, thereby reducing the penetration time and improving the dehydration efficiency.

[0032] (3) The present invention sets an inner drainage mesh and an outer drainage mesh, and a vacuum device is connected to the inner drainage mesh to vacuum the geotube bag. The outer drainage mesh is connected to a motor, which can drive it to rotate and clean up the mud particles adhered to its surface to prevent it from clogging the mesh holes on the three-dimensional drainage board net and affecting the dehydration efficiency.

[0033] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0035] Figure 1 Schematic diagram of the structure of the geotube dewatering device Figure 1 ;

[0036] Figure 2 Schematic diagram of the structure of the geotube dewatering device Figure 2 ;

[0037] Figure 3 It is a schematic diagram of the structure of the horizontal well-shaped groove at the bottom of the geotube bag body;

[0038] Figure 4 It is a schematic diagram of the structure of the top of the geotube bag body;

[0039] Figure 5 It is a side view of the geotube dewatering device;

[0040] Figure 6 It is a structural schematic diagram of a rigid guide column;

[0041] Figure 7 It is a structural schematic diagram of a three-dimensional drainage board net;

[0042] Figure 8 This is a schematic diagram of the structure of the transmission pipeline.

[0043] Reference numerals:

[0044] 1-geotube bag body; 2-vacuum pump; 3-vacuum tube; 4-three-dimensional drainage board net; 401-inner drainage board net; 402-outer 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, turn off the vacuum unit; use an operating device (such as a pile driver) to insert the later drainage structure into the geotube body 1 from the top of the geotube body 1, and use the later drainage structure to further dehydrate the high-water content mud in the geotube body 1.

[0048] Compared with the prior art, the present invention first utilizes the process drainage structure to dehydrate the high-water content mud in the geotube bag body 1, and when the vacuum indication number remains unchanged, the post-drainage structure is used to further dehydrate the high-water content mud in the geotube bag body 1. By dehydrating the high-water content mud in stages, it is ensured that the high-water content mud is dehydrated more thoroughly and efficiently.

[0049] It should be noted that a layer of geomembrane is sealed on the outer surface of the geotube body 1 of the present invention, and the geomembrane is tightly wrapped with the geotube to form a sealed whole, ensuring that the vacuum can be effectively transmitted to improve the air tightness of the entire geotechnical dehydration device.

[0050] In order to achieve rapid dehydration of high-water content mud, the process drainage structure of the present invention includes a plurality of three-dimensional drainage nets 4 parallel to each other and arranged along the length direction of the geotube bag body, and the spacing between adjacent three-dimensional drainage nets 4 is 0.7-1.5m.

[0051] Compared with the prior art, the present invention sets up multiple three-dimensional drainage board nets 4 and evacuates them through a vacuum unit. The large number of mesh holes on the three-dimensional drainage board nets 4 can form a large number of drainage channels, reducing the penetration path of water in high-water content mud, thereby reducing the penetration time and improving the dehydration efficiency.

[0052] The material of the three-dimensional drainage board net 4 of the present invention is degradable polylactic acid fiber.

[0053] It should be noted that the vacuum 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 board net 4 are connected in sequence. The vacuum pump 2 evacuates the three-dimensional drainage board net 4 through the vacuum tube 3 to generate negative pressure in the geotube bag body 1, thereby accelerating the discharge of moisture in the high-moisture content mud and the air in the geotube bag body 1.

[0054] In order to prevent mud particles from clogging the surface of the three-dimensional drainage board 4 during the vacuuming process, causing the vacuum degree to decrease, such as Figure 7 As shown, the three-dimensional drainage board net 4 of the present invention is an oblong tube, which 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; the inner drainage board net is connected to the vacuum extraction device, and the outer drainage board net is connected to the motor, and the vacuum extraction device can vacuum the three-dimensional drainage board net 4; the motor can drive the outer drainage board and the inner drainage board net to rotate relative to each other.

[0055] Specifically, after the high-water content mud is dehydrated by the three-dimensional drainage board net 4 for a period of time, the mud particles in the high-water content mud are easy to adhere to the surface of the three-dimensional drainage board net 4. At this time, the motor is used to drive the outer drainage board to rotate. The outer drainage board net can rotate relative to the adhered mud particles on its surface and then be cleaned up.

[0056] Compared with the prior art, the present invention sets an inner drainage mesh and an outer drainage mesh, and a vacuum device is connected to the inner drainage mesh to vacuum the geotube bag. The outer drainage mesh is connected to a motor, which can drive it to rotate and clean up the mud particles adhered to its surface to prevent it from clogging the mesh holes on the three-dimensional drainage mesh 4 and affecting the dehydration efficiency.

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

[0058] Compared with the prior art, the present invention arranges a transverse guide groove on the inner drainage board net. After the high-water content mud is filled into the geotube bag body 1, the transverse guide groove can accelerate the speed at which water enters the inner drainage board net from the outer drainage board net, thereby accelerating the dehydration rate of the high-water content mud in the geotube bag body 1.

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

[0060] In order to better drive the outer drainage board mesh to rotate, Figure 7 As shown, one end of the three-dimensional drainage board net 4 of the present invention is the vacuum device interface end, and the other end is the closed end; the vacuum device interface end is arranged outside the geotube bag body 1; the closed end is arranged inside the geotube bag body 1; a motor connector is provided at the closed end, and the motor connector is located outside the geotube bag body 1; the output end of the motor is connected to the outer drainage board net through the motor connector, which is used to drive the outer drainage board net to rotate so as to produce relative rotation with the inner drainage board net.

[0061] Specifically, the three-dimensional drainage mesh 4 of the present invention is an oblong tube as a whole, that is, the inner drainage mesh and the outer drainage mesh are both oblong tubes; the vacuum device interface end is arranged outside the geotube bag body 1, the vacuum device interface end is connected to the inner drainage mesh, 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 located 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-water content mud of the geotube bag by providing a rigid guide column 7; the material of the rigid guide column 7 is set to be a rigid material, the purpose of which is to facilitate its insertion into the geotube bag body 1; by providing a plurality of guide grooves on the rigid guide column, the water in the geotube bag can be accelerated to enter the rigid guide column 7; by providing a wedge-shaped guide port 703, on the one hand, it helps to insert it into the geotube bag body 1, and on the other hand, it can guide the water entering the rigid guide groove to the bottom of the geotube bag body 1 and discharge it through the drainage port provided at its bottom.

[0067] In order to facilitate the insertion of the rigid guide column 7 into the geotube bag body 1 in the vertical direction, the rigid guide column 7 of the present invention comprises a fastening section 701 and a guide section 702 from top to bottom; and a guide groove is provided on the guide section 702 .

[0068] It should be pointed out that if Figure 6 As shown, the guide section 702 of the rigid guide column 7 includes a support column 704 and a cylindrical guide shell 705; wherein, the cylindrical guide shell 705 is sleeved outside the support column 704, and the cavity between the two forms a guide space; the top of the support column 704 and the top of the cylindrical guide shell 705 are both integrally formed with the fastening section 701; the guide groove on the guide shell 705 is a vertical guide groove 810, and the vertical guide grooves 810 are evenly arranged along the circumference of the guide shell 705, and the vertical guide grooves 810 are parallel to each other; the vertical guide grooves 810 extend downward to the wedge-shaped guide port 703; the vertical guide grooves 810 are connected to the guide cavity 706 of the guide section 702.

[0069] It should be pointed out that the rigid guide column 7 of the present invention is in the shape of a hexagonal pyramid, and setting it in the shape of a hexagonal pyramid facilitates its insertion into the geotube bag body 1.

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

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

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

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

[0074] In order to facilitate the removal of dehydrated mud, Figure 4 As shown, a zipper structure 6 is provided on the upper surface of the geotube bag of the present invention.

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

[0076] Compared with the prior art, the present invention provides a zipper structure 6 on the geotube bag body 1. After the high-water content mud is drained and consolidated, the zipper structure 6 above the geotube bag body 1 is opened to facilitate the removal of the dehydrated harder soil blocks.

[0077] In order to pretreat high-water content mud, the geotube dewatering system of the present invention further comprises a mud pretreatment device; the high-water content mud pretreated by the mud pretreatment device enters the geotube dewatering device for dehydration treatment.

[0078] Compared with the prior art, the present invention can achieve pretreatment of high-water content mud through the mud pretreatment device, so that the mud can be accumulated into agglomerates to facilitate subsequent dehydration.

[0079] In order to enable the high-water content mud to better aggregate into agglomerates, the pretreatment device of the present invention includes a sedimentation tank and an adjusting tank; the adjusting tank is provided with a flocculation mixer and a flocculant dosing pump; wherein the high-water content mud dredged by the dredger first enters the sedimentation tank for sedimentation, and then is added to the adjusting tank, and then the flocculant dosing pump is used to add the compound flocculant therein, and at the same time, the flocculation mixer is turned on for stirring.

[0080] It should be pointed out that the high-water content mud treated by the geotube dewatering device of the present invention mainly includes dredging mud and engineering mud; the flocculant material used is chitosan (CS)-anionic polyacrylamide (APAM)-calcium chloride (CaCl2) type compound flocculant; chitosan (CS)-anionic polyacrylamide (APAM)-calcium chloride (CaCl2) type compound flocculant can reduce the surface potential of clay particles, compress the double electric layer and adsorb and bridge the effect, so that the particles change from a stable state to an unstable state, and the particles aggregate into clusters.

[0081] Compared with the prior art, the present invention uses the above-mentioned compound flocculant to make the high-water content mud accumulate into agglomerates under the action of flocculation, which is not easy to block the three-dimensional drainage board 4 and the rigid guide column 7 during the drainage process, and finally accelerates the drainage consolidation rate in the geotube bag, which is of great significance to my country's environmental protection, pollution prevention and control, solid waste resource utilization and sustainable development.

[0082] In order to transport the pre-treated high-water content mud, the geotube dewatering system of the present invention further comprises a mud transporting device; the mud transporting device is used to transport the high-water content mud after flocculation treatment to the geotube dewatering device.

[0083] Compared with the prior art, the present invention can transport high-water content mud to the geotube dehydration device for dehydration treatment through the mud transportation device.

[0084] In order to avoid sedimentation when transporting pretreated high-water content mud, the mud conveying device invented this year includes a conveying pipe 10 and a mixing component; the mixing component is arranged in the conveying pipe 10; one end of the conveying pipe 10 is connected to the mud pretreatment device, and the other end is connected to the geotube dewatering device, which is used to transport the high-water content mud after flocculation pretreatment to the geotube body 1.

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

[0086] In order to further improve the uniformity of mixing flocculants with high water content mud, Figure 8 As shown, the mixing component of the present invention includes a front spoiler 11, an agitator 12 and a rear spoiler 13; wherein the front spoiler 11 is arranged in front of the agitator 12, and the rear spoiler 13 is arranged behind the agitator 12, and both are fixed on the inner wall of the conveying pipe 10.

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

[0088] It should be pointed out that if Figure 8As shown, the front spoiler 11 and the rear spoiler 13 of the present invention have the same structure, and both include 2-3 hollow truncated cone-shaped spoilers arranged in parallel with each other; the hollow truncated cone-shaped spoilers are arranged at equal intervals along the axial direction of the conveying pipe 10; one end of the hollow truncated cone-shaped spoiler is a truncated cone large end, and the other end is a truncated cone small end, wherein the outer diameter of the truncated cone large end is the same as the inner diameter of the conveying pipe 10, and the hollow truncated cone-shaped spoiler is welded to the inner wall of the conveying pipe 10 through its large end; the truncated cone small end faces the inflow direction of the high-water content mud, and a rectangular serrated groove 14 is provided on the circumferential direction of the truncated cone small end.

[0089] Compared with the prior art, the present invention can reduce the flow rate of the high-water content mud and flocculant mixture by arranging multiple hollow frustum-shaped spoilers, and at the same time further enhance the mixing degree of the high-water content mud and flocculant, so that the high-water content mud can be better aggregated into agglomerates.

[0090] On the other hand, the present invention also provides a method for dehydrating a geotube bag of high-water-content slurry, which uses the above-mentioned geotube bag dehydration system for high-water-content slurry to perform dehydration; specifically, the method comprises the following steps:

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

[0092] Step 11: Use an environmentally friendly cutter suction dredger to carry out construction operations;

[0093] Step 12: The dredged sludge (mud with high water content) excavated 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 regulating tank, and use a mechanical stirrer to stir the sludge and flocculant solution. The stirring time is 3 minutes to 5 minutes.

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

[0096] In the above-mentioned compound flocculants, the surface of CS is positively charged, and the surface of soil particles is negatively charged. CS attracts soil particles through electrical neutralization and adsorption bridging. The long molecular chain of APAM contains polar groups, which can attract small soil particles in the mud through adsorption bridging to form large-sized flocs, thereby achieving rapid precipitation. 2+ It can further neutralize the negative charge on the surface of 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 composite flocculant of the present invention is: first, dissolve the chitosan powder in water to form a solution, pour it into the mud 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 mixture of the above chitosan and mud, 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 mixture formed by the above chitosan-APAM and mud, and stir for 2-3 minutes.

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

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

[0101]

[0102] Where:

[0103] Q y - The flow rate of the added agent is in cubic meters per hour (m 3 / h);

[0104] Q n - Mud flow, in cubic meters per hour (m 3 / h);

[0105] C y - Drug concentration, in kilograms per cubic meter (kg / m 3 );

[0106] C n - Mud concentration, in kilograms per cubic meter (kg / m 3 );

[0107] K is the ratio of the mass of the reagent to the mass of the dry soil in the mud, dimensionless. The K value is determined by experiment.

[0108] In summary, the present invention can aggregate smaller clay particles into agglomerates by adding a compound flocculant, which makes it difficult for smaller clay particles to flow out of the pores of the geotube bag on the one hand; on the other hand, when vacuuming, the large-particle mud that is flocculated into agglomerates is not easy to block the three-dimensional drainage board net 4, thereby improving the construction efficiency. The fine clay particles in the high-water content mud begin to aggregate into agglomerates under the adsorption bridging and electrical neutralization of the flocculant hydrolysis products, and then settle after forming larger particle clusters. During the filling process, the water in the high-water content mud is precipitated, and under the action of its own gravity, the water precipitates from the pores on the surface of the geotube bag.

[0109] Step 2: using a mud conveying device to convey the high-water content mud after flocculation treatment to a geotube dewatering device;

[0110] The high-water content mud after flocculation treatment is transported to the geotube bag body 1 through the conveying pipe 10. During the transportation process, the front spoiler 11, the agitator 12 and the rear spoiler 13 in the conveying pipe 10 can mix the high-water content mud and the compound flocculant again, further improving the mixing uniformity of the two.

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

[0112] Step 31, first use the process drainage structure to dehydrate the high-water content mud in the geotube bag body 1;

[0113] After the high-water-content mud is filled into the geotube bag body 1, the high-water-content mud is first drained under the action of its own gravity; then the vacuum pump 2 is turned on, and the vacuum pump 2 vacuums the three-dimensional drainage board net 4 through the vacuum tube 3 to generate negative pressure in the geotube bag body 1, thereby accelerating the discharge of water in the high-water-content mud and air in the geotube bag body 1.

[0114] Step 32: Dewater the high-water content slurry in the geotube bag body 1 using the post-drainage structure.

[0115] After the vacuum indication remains unchanged and the sludge in the geotube is consolidated by its own gravity for a period of time, the water content of the high-water content mud is reduced by 50%, and the vacuum unit is turned off; the zipper on the top of the geotube is opened, and a plurality of rigid guide columns 7 are inserted into the geotube body 1 from the top of the geotube body 1 by a pile driver in the vertical direction by vibration or static pressure; the high-water content mud in the geotube body 1 is further dehydrated by the rigid guide columns 7. After dehydration is completed, the consolidated sludge is randomly sampled on the surface of the geotube with a soil sampler, and the water content of the samples is tested on site; if the average water content of the samples has dropped below 30%, it indicates that the dehydration is completed.

[0116] Compared with the prior art, the present invention dehydrates the high-water content mud in stages to ensure that the high-water content mud is dehydrated more thoroughly and efficiently. The moisture content of the soil after dehydration is reduced to 30%, which can shorten the construction period, improve the utilization rate of geotube bags, and improve the efficiency of land turnover.

[0117] The process of dehydrating the geotube bag dehydration system using the above-mentioned high-water content mud includes:

[0118] Step 1: pretreating the high water content mud using a mud pretreatment device; specifically comprising the following sub-steps:

[0119] Step 11: Use an environmentally friendly cutter suction dredger to carry out construction operations;

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

[0121] It should be pointed out that a wire mesh with an aperture of 1 mm is laid above the sedimentation tank to remove white garbage and large rocks from the dredged mud. The mud with preliminary impurities removed falls into the sedimentation tank and waits for 1 hour to allow the mud and sand to sink to the bottom under its own gravity.

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

[0123] It should be pointed out that the regulating volume of the regulating tank is calculated according to the following formula:

[0124] V=T·|Q0-Q n And V ≥ 0.5Q0, V ≥ 0.5Q1 (1)

[0125] Where:

[0126] V - the regulating volume of the regulating pool, in cubic meters (m 3 );

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

[0128] Q n - Mud flow rate for subsequent treatment, in cubic meters per hour (m 3 / h), n is a natural number; T is the interval between stopping the extraction of mud due to the minimum liquid level in the regulating tank or stopping the entry of mud due to the maximum liquid level in the regulating tank, in hours (h); T is greater than or equal to 2h.

[0129] In the dewatering site where the mud is dehydrated by geotube bags, if it is necessary to transport the consolidated soil out in time and reuse the dewatering site, the total area of ​​the dewatering site can be divided into several working surfaces of equal area. If the number of working surfaces is determined to be n, the total area of ​​the dewatering site required is calculated according to the following formula (2):

[0130]

[0131] If the total area F of the dehydration site is determined, the number of working surfaces that need to be divided is calculated according to the following formula (3):

[0132]

[0133] The grouting time Y1 of a single working face is calculated as follows:

[0134]

[0135] The excavation time Y3 of a single working face is calculated as follows:

[0136]

[0137] Where:

[0138] F - total area of ​​dehydration site, in square meters (m 2 );

[0139] n is the number of working surfaces, which is actually an integer, and the integer digit of the value calculated in formula (3) is added by 1, and it is dimensionless;

[0140] W - the mass of dry mud processed daily, W = Q n C n T / 1000, unit is tons per day (t / d);

[0141] Q n - Mud flow, in cubic meters per hour (m 3 / h);

[0142] C n - Mud concentration, in kilograms per cubic meter (kg / m 3 );

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

[0144] Y1 - the grouting time required for all geotubes on a single working surface to be filled with slurry, in days (d);

[0145] Y2 - the time for water seepage and drying from the end of grouting to the excavation of a single working face, in days (d), Y2 is greater than or equal to 15d;

[0146] Y3―The time required to transport all the consolidated soil from a single working face, in days (d);

[0147] Y4―idle time of a single working face, in days (d);

[0148] H - the maximum stacking height of geotube bags, in meters (m), H is greater than or equal to 15m;

[0149] M-the bulk dry density of the soil in the tube bag after dehydration, in tons per cubic meter (t / m 3 );

[0150] P - daily volume of soil transported out, in cubic meters per day (m 3 / d).

[0151] Step 2: When the high-water content slurry in the regulating tank is transported to the geotube bag body 1, the velocity gradient G value of the mixer in the transport pipeline 10 is greater than 600s -1 , the head loss of the mixer is less than or equal to 0.5m;

[0152] Step 3: After the geotube bag is filled and reaches the designed height, the vacuum pump 2 is turned on, and the high-water content mud in the geotube bag body 1 is first dehydrated using the process drainage structure; and then the high-water content mud in the geotube bag body 1 is dehydrated using the post-drainage structure. After the drainage and consolidation are completed, the zipper structure 6 on the top of the geotube bag is opened to remove the harder soil blocks in the geotube bag from the top.

[0153] The above description is only a 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 conceived by any technician familiar with the technical field 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 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, 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; 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 using the post-drainage structure.

2. The geotube dewatering system for high-water content slurry according to claim 1 is characterized in that: The process drainage structure includes a plurality of three-dimensional drainage panels which are parallel to each other and arranged along the length direction of the geotube bag body.

3. The geotube dewatering system for high-water content slurry according to claim 2, characterized in that: 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; The inner drainage board net is connected to the vacuum device, 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 generate relative rotation with the inner drainage board net.

4. The geotube dewatering system for high-water content slurry according to claim 3, 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.

5. The geotube dewatering system for high-water content slurry according to claim 4, 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.

6. 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.

7. The geotube dewatering system for high-water content slurry according to claim 6, 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.

8. The geotube dewatering system for high-water content slurry according to claim 7, 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.

9. 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 mud according to any one of claims 1 to 8; the geotube bag dehydration method for high-water-content mud 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.

10. The method for dehydrating geotube bags of high-water content slurry according to claim 9, 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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