Ecological dredging bottom mud water thermal phase change vacuum preloading dewatering and drying system and method

Abstract

The invention relates to an ecological dredging bottom mud water thermal phase change vacuum preloading dehydration drying system and method, and the system comprises a vertical drainage system which comprises a plastic drainage plate, a drainage branch pipe and a double-hand-plate joint; the vacuum loading system comprises a vacuum pump and a water-vapor separation tank, the water-vapor separation tank is connected with a drainage main pipe, and the drainage main pipe is connected with a drainage branch pipe through a tee joint; the high-temperature hot water circulation loading system comprises a heat preservation heating water tank, a water guide main pipe, steel wire hoses and U-shaped heating pipes, the heat preservation heating water tank is connected with the steel wire hoses through the water guide main pipe, and the steel wire hoses are connected with the U-shaped heating pipes; the temperature control system is used for detecting the water temperature of the heat-preservation heating water tank and heating the heat-preservation heating water tank; the sealing system comprises geotechnical cloth and polyvinyl chloride sealing films, the geotechnical cloth is laid in a layered mode, and the polyvinyl chloride sealing films are pressed into the film pressing grooves in the boundary of the dehydration area respectively. The bottom is heated by adopting a hot water circulating system, the bottom mud is heated, the permeability of the bottom mud is improved, and rapid dehydration and drying are realized in combination with vacuum preloading.

Description

Technical Field

[0001] The invention relates to the technical field of ecological dredging sludge dehydration and drying, and in particular to an ecological dredging sludge hydrothermal phase change vacuum pre-pressing dehydration and drying system and method. Background Art

[0002] Ecological dredging of sediment refers to the process of mixing sediment from rivers, lakes and reservoirs with a large amount of water and blowing it to the surface through human, hydraulic or mechanical means. Sediment is generally composed of a large amount of water, clay, silt and a small amount of organic matter. Its water content is greater than its liquid content and its porosity is greater than 1.5. It has the characteristics of high water content, poor permeability, large porosity and strong compressibility. In recent years, my country has vigorously supported the construction of disaster prevention, mitigation and relief capabilities, and the development of increasing the flow and capacity of rivers, lakes and reservoirs has ushered in an opportunity. However, a large amount of sediment will be generated in the process of ecological dredging. The reduction and resource utilization of sediment have become the key factors restricting the implementation of such projects. For the reduction of sediment, the existing dehydration and drying technologies mainly include: vacuum preloading, pressurization (gas splitting) vacuum preloading, electroosmotic vacuum preloading, geotube bags, mechanical dehydration (plate and frame filter press, belt filter press) and electric heating vacuum preloading. The single vacuum preloading method has a long construction period and poor effect. The pressurized (gas splitting) vacuum preloading can only partially improve the dehydration effect of vacuum preloading. Geotextile tube bags also have similar problems. The complex process, high cost and poor stability of electroosmotic vacuum preloading are the key reasons why it has not been widely used. Mechanical dehydration is restricted by factors such as high cost, low efficiency and limited production capacity. Electric heating vacuum preloading heats the bottom mud by converting electrical energy into thermal energy through heating elements, changing the phase state of water in the bottom mud, improving the permeability of water in the bottom mud, and achieving the purpose of rapid dehydration and drying. Many scholars have studied the influence of heating technology on the dehydration and consolidation of bottom mud in the existing technology. However, it is found in the existing literature and engineering applications that the heating device in the electric heating vacuum preloading has the problem that the temperature cannot be accurately controlled, the temperature change can reach tens to hundreds of degrees, the loading temperature is too high, and energy consumption is wasted. At the same time, the electric heating construction site has complex lines, many joints, many electrical boxes, and many lines. Many line groups are immersed in water, which is highly dangerous and the construction process is complicated. Therefore, based on these problems, it is of great practical significance to provide an ecological dredging sludge hydrothermal phase change vacuum pre-pressing dehydration drying system and method. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide an ecological dredging sludge hydrothermal phase change vacuum pre-pressing dehydration and drying system and method.

[0004] The present invention is achieved through the following technical solutions:

[0005] An ecological dredging sludge hydrothermal phase change vacuum pre-pressing dehydration and drying system, comprising:

[0006] A vertical drainage system, comprising a plastic drainage board, a drainage branch pipe and a double-hand board joint, wherein the drainage branch pipe is connected to a vacuum loading system;

[0007] A vacuum loading system, comprising a vacuum pump and a water vapor separation tank, wherein the vacuum pump is connected to the water vapor separation tank, the water vapor separation tank is connected to a drainage main pipe, and the drainage main pipe is connected to a drainage branch pipe of the vertical drainage system through a tee;

[0008] The high-temperature hot water circulation loading system includes a heat preservation and heating water tank, a water guide pipe, a steel wire hose and a U-shaped heating pipe. The heat preservation and heating water tank is connected to a plurality of steel wire hoses through the water guide pipe, and the steel wire hose is connected to the U-shaped heating pipe.

[0009] A temperature control system, acting on the heat preservation and heating water tank of the high-temperature hot water circulation loading system, is used to detect the water temperature of the heat preservation and heating water tank and heat it;

[0010] The sealing system comprises two layers of geotextiles and two layers of polyvinyl chloride sealing films. The geotextiles are laid in layers, and the polyvinyl chloride sealing films are respectively pressed into the film pressing grooves at the boundaries of the dehydration zone to form a sealing system.

[0011] According to the above technical solution, preferably, the high-temperature hot water circulation loading system also includes a hot water circulation pump and a pipeline diverter, the thermal insulation and heating water tank is connected to a water main pipe, a hot water circulation pump is provided on the water main pipe, and the water main pipe is connected to a plurality of steel hoses through the pipeline diverter.

[0012] According to the above technical solution, preferably, the temperature control system includes a heating rod located in the thermal insulation and heating water tank, a temperature sensor and a temperature control device connected to the outside of the thermal insulation and heating water tank, the temperature sensor is connected to the temperature control device outside the thermal insulation and heating water tank, and the temperature control device controls the operation of the heating rod according to the water temperature in the thermal insulation and heating water tank.

[0013] According to the above technical solution, preferably, the inner and outer layers of the thermal insulation and heating water tank are stainless steel plates, and polyurethane foam glue is filled in between.

[0014] According to the above technical solution, preferably, the water-conducting main pipe is an iron pipe, and the outer side is wrapped with a rubber sponge insulation layer.

[0015] According to the above technical solution, preferably, the steel wire hose has a temperature resistance of above 120°C and can withstand a pressure of above 0.2MPa, and the steel wire hose is wrapped with a rubber sponge layer.

[0016] According to the above technical solution, preferably, a frustum is provided at the top end of the U-shaped heating tube, the frustum is connected to the steel wire hose, and the connection is fixed with a clamp.

[0017] The present application also discloses a method for dehydrating and drying ecological dredged sludge by hydrothermal phase change vacuum preloading, based on the above-mentioned system for dehydrating and drying ecological dredged sludge by hydrothermal phase change vacuum preloading, comprising the following steps:

[0018] S1. Laying the working mat, the working mat comprises a layer of woven cloth, two layers of Jingba and a layer of woven cloth laid sequentially;

[0019] S2. The plastic drainage board is inserted into the bottom of the silt by a board inserting machine;

[0020] S3. After the high-temperature hot water circulation loading system is connected, the U-shaped heating pipe is inserted into the bottom of the sludge by a plug-in machine;

[0021] S4. Assemble and connect the plastic drain board, drain branch pipe, double-hand plate joint in the vertical drainage system, and connect the drain branch pipe to the drain main pipe through a tee to complete the connection with the vacuum loading system;

[0022] S5. Sequentially lay two layers of geotextile and two layers of polyvinyl chloride sealing membrane, and the polyvinyl chloride sealing membrane is layered and stepped into the film pressing groove to form a complete closed system;

[0023] S6. The water in the heat preservation and heating water tank is heated to 80°C and then the heating is stopped;

[0024] S7. Vacuum loading step by step through the vacuum loading system;

[0025] S8. After the vacuum preloading is fully loaded, the heat preservation and heating water tank is opened, and the hot water circulation pump is started to form a high-temperature hot water circulation loop to heat the bottom mud;

[0026] S9. After continuous loading, hot water circulation heating is completed, and then after continuous full load vacuuming, hydrothermal phase change vacuum pre-pressing dehydration is completed.

[0027] The beneficial effects of the present invention are:

[0028] The present invention adopts hot water circulation to heat the bottom mud, which can accurately control the temperature change of the surface of the heating element, solves the problem that the temperature cannot be accurately controlled in electric heating, and solves the problem that the bottom mud around the point heating element loses water quickly and hardens, forming a water-proof curtain due to excessive temperature.

[0029] At the same time, the present invention adopts a hot water circulation system to heat the bottom, and the construction process is simple, avoiding the problems of complex traditional electric heating network cable connections, multiple interfaces, and cluttered out-of-control electrical boxes, greatly reducing electricity safety issues, while reducing the high temperature and high energy consumption of electric heating, achieving the green and low-carbon development goals. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1It is a process flow diagram of the method for hydrothermal phase change vacuum pre-pressing dehydration and drying of ecological dredged sludge in the present invention.

[0031] Figure 2 It is a top view structural schematic diagram of the ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system in the present invention.

[0032] Figure 3 It is a schematic cross-sectional structure diagram of the ecological dredging sludge hydrothermal phase change vacuum pre-pressing dehydration and drying system of the present invention.

[0033] Figure 4 It is a schematic diagram of the cross-sectional structure of the U-shaped heating tube in the present invention.

[0034] Figure 5 It is a schematic diagram of the cross-sectional structure of the water-conducting main pipe in the present invention.

[0035] Figure 6 It is a schematic diagram of the cross-sectional structure of the medium heat-insulating heating water tank of the present invention.

[0036] In the figure: 1. Insulated heating water tank; 2. Ball valve switch; 3. Hot water circulation pump; 4. Water guide pipe; 5. Pipeline diverter; 6. Steel wire hose; 7. U-shaped heating pipe; 8. Double-hand plate joint; 9. Plastic drain board; 10. Drainage branch pipe; 11. Drainage main pipe; 12. Vacuum loading system; 13. Tee; 14. Water outlet; 15. Clamp; 16. Water ring vacuum pump; 17. Water vapor separation tank; 18. Geotextile; 19. Polyvinyl chloride sealing membrane; 20. Temperature sensor; 21. Water inlet; 22. Heating rod; 23. Temperature control device; 24. Round table; 25. Rubber sponge insulation layer; 26. 201 stainless steel plate; 27. 304 stainless steel plate; 28. Polyurethane foam glue. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and the best embodiment. Based on the embodiments in the invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the invention.

[0038] In the description of the invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the invention.

[0039] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Embodiment 1: As shown in the figure, the present invention includes a vertical drainage system, a vacuum loading system 12, a high-temperature hot water circulation loading system, a temperature control system and a sealing system.

[0041] The vertical drainage system includes a plastic drainage board 9, a drainage branch pipe 10 and a double-hand board joint 8. The plastic drainage board 9 is connected to the drainage branch pipe 10 through the double-hand board joint 8, and the drainage branch pipe 10 is connected to the drainage main pipe 11 of the vacuum loading system 12 through a tee 13.

[0042] The vacuum loading system 12 includes a water ring vacuum pump 16 and a water vapor separation tank 17. The water ring vacuum pump 16 is connected to the water vapor separation tank 17, the water vapor separation tank 17 is connected to the drainage main pipe 11, the drainage main pipe 11 is connected to the drainage branch pipe 10 through a tee 13, and the drainage branch pipe 10 is connected to the double-hand plate to form the vacuum loading system 12.

[0043] The high-temperature hot water circulation loading system includes a heat preservation and heating water tank 1, a hot water circulation pump 3, a water guide pipe 4, a pipe diverter 5, a high-temperature resistant steel wire hose 6 and a stainless steel U-shaped heating pipe 7. In this example, the outer layer of the heat preservation and heating water tank 1 is a 201 stainless steel plate 26 with a thickness of 0.4 mm, and the inner liner is a 304 stainless steel plate 27 with a thickness of 1.5 mm, and polyurethane foam glue 28 is filled in between. The thermal insulation and heating water tank 1 has a water outlet 14 at the bottom, and a water inlet 21 at the top of the thermal insulation and heating water tank 1. A ball valve switch 2 is installed at the water outlet 14. The ball valve switch 2 is connected to the hot water circulation pump 3. The water guide pipe 4 is connected to the hot water delivery pump. A diverter is installed on the water guide pipe 4. The water guide pipe 4 is made of an iron pipe with a diameter of 100 mm and a thickness of 3 mm. The outer side is wrapped with a rubber sponge insulation layer 25, and the thickness of the rubber sponge insulation layer 25 is 50 mm; the diverter has a diameter of 25 mm and is connected to the high-temperature resistant steel wire hose 6. The high-temperature resistant steel wire hose 6 has a temperature resistance of 120°C and can withstand a pressure of 0.2 MPa. The high-temperature resistant steel wire hose 6 exposed to the air is wrapped with a rubber sponge insulation layer 25, and the thickness of the rubber sponge insulation layer 25 is 50 mm. The high temperature resistant steel wire hose 6 is connected to the stainless steel U-shaped heating tube 7. The stainless steel U-shaped heating tube 7 is made of 304 stainless steel, with a diameter of 25 mm and a thickness of 1.5 mm. The inner edge spacing of the U-shaped tube is 120 mm, the outer diameter is 170 mm, and there are 4 cones 24 on the top. The spacing between the cones 24 is 5 mm. The cones 24 are connected to the high temperature resistant stainless steel tube, and the connection is fixed with a clamp 15 to prevent water leakage.

[0044] The temperature control system is to install a temperature sensor 20 in the heat preservation and heating water tank 1 to monitor the water temperature in the water tank in real time. The temperature sensor 20 is connected to an external temperature control device 23, and the temperature control device 23 controls the operation of the heating rod 22 inside the heat preservation and heating water tank 1. In this example, a heating rod 22 is installed inside the water tank, and the power of the heating rod 22 can be customized according to the volume of the water tank. A temperature sensor 20 is installed at the center of the water tank, and the temperature sensor 20 is connected to an external temperature control device 23. The temperature control device 23 can control the operation of the heating rod 22 according to the water temperature in the water tank.

[0045] The sealing system is composed of two layers of geotextiles 18 and two layers of polyvinyl chloride sealing membranes 19. The geotextiles 18 are laid in layers, and the sealing membranes are pressed into the membrane pressing grooves at the boundaries of the dehydration area to form a sealing system.

[0046] Example 2: The present application also discloses an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying method, based on the above-mentioned ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system, comprising the following steps:

[0047] Step S1: laying a working cushion layer, the working cushion layer comprising: laying a layer of woven cloth, two layers of jingba and a layer of woven cloth in sequence;

[0048] Step S2: insert the plastic drain board to the bottom of the sludge manually or by a track-type board inserting machine. The bottom of the plastic drain board is bent back and folded 20 cm to prevent the drain board from being blocked. The spacing between the drain boards is 0.8 m.

[0049] Step S3: Insert the stainless steel U-shaped heating pipe connected to the high-temperature resistant steel wire hose 1m away from the bottom of the mud, one end of the high-temperature resistant steel wire hose is connected to the hot water circulation pump, and the hot water circulation pump is connected to the water outlet of the thermal insulation and heating water tank. The high-temperature resistant steel wire hose can be connected in series with multiple stainless steel U-shaped heating pipes, with a plane insertion spacing of 3m, and the other end is connected to the water inlet of the thermal insulation and heating water tank to form a high-temperature hot water circulation loop.

[0050] Step S4: Connect the plastic drain plate through a double-hand plate, connect the double-hand plate to the drain branch pipe, the drain branch pipe is a steel hose with a diameter of 25 mm, the drain branch pipe is connected to the drain main pipe through a tee, the drain main pipe is a steel hose with a diameter of 50 mm; the drain main pipe is connected to the water vapor separation tank, and the water vapor separation tank is connected to the water ring vacuum pump through the steel hose;

[0051] Step S5: After step S4 is completed, two layers of geotextiles and two layers of sealing membranes are laid thereon in sequence, and the sealing membranes are stepped into the film pressing grooves in layers to form a complete closed system;

[0052] Step S6: Before the vacuum preloading is fully loaded, the water in the heat preservation and heating water tank is heated to 80° C., and then the heating is stopped.

[0053] Step S7: vacuum loading step by step, setting the vacuum pressure to 20 kPa, the loading time to 2 days, then setting the vacuum pressure to 40 kPa, the loading time to 2 days, then setting the vacuum pressure to 60 kPa, the loading time to 3 days, and finally setting the vacuum pressure to 85 kPa to reach full load;

[0054] Step S8: After the vacuum preloading is fully loaded, open the ball valve switch of the water inlet of the insulation and heating water tank, start the hot water circulation pump, form a high-temperature hot water circulation loop, and start heating the bottom mud. Due to the low temperature of the bottom mud, the water in the insulation and heating water tank gradually decreases after reflux. When the water temperature in the insulation and heating water tank is lower than 70°C, the temperature control system controls the heating rod to start and start heating. When the water temperature in the insulation and heating water tank is greater than 80°C, stop heating the heating rod.

[0055] Step S9: According to step S8, hot water circulation heating is completed after continuous loading for 24 days, and hydrothermal phase change vacuum pre-pressing dehydration is completed after continuous full load vacuuming for 60 days.

[0056] The present invention couples the hot water circulation loading system and the vacuum preloading system, and on the basis of vacuum preloading, couples the hot water circulation loading to reduce the cohesion between water and soil particles in the bottom mud, suddenly changes the permeability coefficient of the bottom mud, increases the permeability of water vapor in the bottom mud, and achieves the purpose of rapid dehydration and drying. At the same time, the hot water circulation loading can accurately control the loading temperature, avoid the formation of a "heat-proof insulation wall" in the bottom mud due to high temperature, save energy consumption, simplify the construction process, and improve the safety of construction and operation.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system, characterized in that: include: A vertical drainage system comprises a plastic drainage board (9), a drainage branch pipe (10) and a double-hand board joint (8), wherein the drainage branch pipe (10) is connected to a vacuum loading system (12); A vacuum loading system (12) comprises a vacuum pump and a water vapor separation tank (17), wherein the vacuum pump is connected to the water vapor separation tank (17), the water vapor separation tank (17) is connected to a drainage main pipe (11), and the drainage main pipe (11) is connected to a drainage branch pipe (10) of the vertical drainage system via a tee (13); A high-temperature hot water circulation loading system comprises a heat preservation and heating water tank (1), a water guide pipe (4), a steel wire hose (6) and a U-shaped heating pipe (7), wherein the heat preservation and heating water tank (1) is connected to a plurality of steel wire hoses (6) via the water guide pipe (4), and the steel wire hose (6) is connected to the U-shaped heating pipe (7); The temperature control system acts on the heat preservation and heating water tank (1) of the high-temperature hot water circulation loading system and is used to detect the water temperature of the heat preservation and heating water tank (1) and heat the water.

2. According to claim 1, an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system is characterized in that: The high-temperature hot water circulation loading system further comprises a hot water circulation pump (3) and a pipeline diverter (5). The heat preservation and heating water tank (1) is connected to a water pipe (4), a hot water circulation pump (3) is provided on the water pipe (4), and the water pipe (4) is connected to a plurality of steel hoses (6) via the pipe diverter (5).

3. According to claim 2, an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system is characterized in that: The temperature control system comprises a heating rod (22) located in the thermal insulation and heating water tank (1), a temperature sensor (20), and a temperature control device (23) connected to the outside of the thermal insulation and heating water tank (1). The temperature sensor (20) is connected to a temperature control device (23) outside the thermal insulation and heating water tank (1), and the temperature control device (23) controls the operation of the heating rod (22) according to the water temperature in the thermal insulation and heating water tank (1).

4. According to claim 3, an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system is characterized in that: The inner and outer layers of the heat-insulating heating water tank (1) are stainless steel plates, and polyurethane foam glue (28) is filled in between.

5. According to claim 2, an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system is characterized in that: The water-conducting main pipe (4) is an iron pipe, and the outer side is wrapped with a rubber sponge insulation layer (25).

6. According to claim 5, an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system is characterized in that: The steel wire hose (6) has a temperature resistance of more than 120° C. and a pressure resistance of more than 0.2 MPa. The steel wire hose (6) is wrapped with a rubber sponge layer.

7. According to claim 6, an ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system is characterized in that: A round platform (24) is provided at the top end of the U-shaped heating tube (7), and the round platform (24) is connected to the steel wire hose (6), and the connection is fixed by a clamp (15).

8. The ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system according to any one of claims 2 to 7, characterized in that: Also includes: The sealing system comprises two layers of geotextile (18) and two layers of polyvinyl chloride sealing membrane (19). The geotextile (18) is laid in layers, and the polyvinyl chloride sealing membrane (19) is pressed into the film pressing grooves at the boundaries of the dehydration zone to form a sealing system.

9. An ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying method, based on the ecological dredging sludge hydrothermal phase change vacuum preloading dehydration and drying system described in claim 8, characterized in that: The steps include: S1. Laying the working mat, the working mat comprises a layer of woven cloth, two layers of Jingba and a layer of woven cloth laid sequentially; S2. The plastic drainage board (9) is inserted into the bottom of the sludge by a board inserting machine; S3. After the high-temperature hot water circulation loading system is connected, the U-shaped heating tube (7) is inserted into the bottom of the sludge by a plug-in machine; S4. Assemble and connect the plastic drain board (9), drain branch pipe (10), and double-hand plate joint (8) in the vertical drainage system, and connect the drain branch pipe (10) to the drain main pipe (11) through a tee (13), and complete the connection with the vacuum loading system (12); S5. Sequentially lay two layers of geotextile (18), two layers of polyvinyl chloride sealing film (19), the polyvinyl chloride sealing film (19) is layered into the film pressing groove to form a complete closed system; S6. The water in the heat preservation and heating water tank (1) is heated to 80°C and then the heating is stopped; S7. Vacuum loading step by step through the vacuum loading system (12); S8. After the vacuum preloading is fully loaded, the heat preservation and heating water tank (1) is opened, and the hot water circulation pump (3) is started to form a high-temperature hot water circulation loop to heat the bottom mud; S9. After continuous loading, hot water circulation heating is completed, and then after continuous full load vacuuming, hydrothermal phase change vacuum pre-pressing dehydration is completed.

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