Landfill gas guiding and draining structure

Abstract

The utility model belongs to landfill gas processing technical field especially, it is a kind of landfill gas guide structure, including, the multiple gas guide column units of being arranged in landfill foundation pit bottom;Gas guide column unit includes deep burying in foundation pile, and the multiple section gas guide pipe fixed in pile top;The support cage body is provided on the pile, and the support cage body is sleeved in the outside of gas guide pipe;Support cage body is filled with broken stone filter material layer, the support cage body circumference is evenly provided with several gas collector, and one end of gas collector passes through support cage body and is embedded in broken stone filter material layer. Through the multiple section gas guide pipe vertically arranged and the gas collector laterally arranged, ensure collection efficiency. Through the pile of deep burying in foundation to support the multiple section gas guide pipe vertically arranged, avoid gas guide pipe settlement;And one end of gas collector passes through support cage body and is embedded in broken stone filter material layer, ensure gas to flow into gas guide pipe, avoid lateral gas collector to break down and fail due to settlement.

Description

Technical Field

[0001] This utility model belongs to the field of landfill gas treatment technology, and in particular relates to a landfill gas discharge structure. Background Technology

[0002] With the rapid development of the municipal solid waste incineration industry, the amount of waste incinerated is increasing year by year. At the same time, the fly ash produced is heavy metal waste that needs to be landfilled. The heavy metals in the landfill have an impact on the soil environment. Therefore, higher and stricter requirements are put forward for the design of solidified fly ash landfills.

[0003] Landfills must be equipped with effective landfill gas drainage facilities to prevent fires and explosions caused by the natural accumulation and migration of landfill gases. Drainage wells or blind drainage channels, or a combination thereof, should be installed within the landfill waste pile. Currently, landfill gas collection and drainage typically utilize vertical and horizontal wells.

[0004] When traditional gas-conducting wells are used in solidified fly ash landfills, the following specific problems may exist: 1. The stability of solidified fly ash and well settlement are contradictory. After solidification, fly ash forms a blocky mass, and its overall settlement may be uneven with the surrounding soil, generating shear force on the rigid gas well and easily leading to well pipe breakage.

[0005] 2. Collection efficiency issues due to differences in gas production characteristics. The gas production of fly ash landfills may be less than that of raw landfills, and the gas distribution is more uneven. The collection radius of traditional vertical wells may be insufficient, resulting in blind spots. Utility Model Content

[0006] In view of the technical problems existing in the background art, this utility model provides a landfill gas drainage structure.

[0007] To achieve the above objectives, the technical solution provided by this utility model is as follows: A landfill gas discharge structure, comprising, Multiple air-guiding column units are installed at the bottom of the landfill pit; The air-guiding column unit includes a cast-in-place pile deeply embedded in the foundation, and multiple sections of air-guiding pipe fixed to the top of the cast-in-place pile; a support cage is provided on the cast-in-place pile, and the support cage is sleeved on the outside of the air-guiding pipe. The support cage is filled with a layer of crushed stone filter material, and several air collection pipes are evenly distributed around the circumference of the support cage. One end of each air collection pipe passes through the support cage and is embedded in the crushed stone filter material layer.

[0008] Optionally, the gas collecting pipe includes a pre-embedded steel pipe, a corrugated pipe, and an extended gas pipe. The pre-embedded steel pipe is installed in the support cage and pre-embedded in the crushed stone filter material layer. The pre-embedded steel pipe is connected to the corrugated pipe. One end of the corrugated pipe is connected to the extended gas pipe. The extended gas pipe has a number of filter holes evenly distributed around its circumference.

[0009] Optionally, the extended air pipe is provided with one section and is located at the high end of the landfill.

[0010] Optionally, the extended air pipe is provided with several sections and is located at the lower end of the landfill. The several sections of the extended air pipe are connected by corrugated pipes, and the extended air pipes at both ends are respectively connected to the pre-buried steel pipes on both sides.

[0011] Optionally, the pre-embedded steel pipe has a number of filter holes evenly distributed around its circumference.

[0012] Optionally, the upper and lower ends of the air guide pipe are respectively provided with mounting flanges for pipe connection; the support cage includes an outer steel mesh cage and an inner steel mesh cage, the inner steel mesh cage is tightly attached to the outer wall of the mounting flange, the inner steel mesh cage and the air guide pipe form an air collection cavity, and the inner steel mesh cage and the outer steel mesh cage are spaced apart to form a filling cavity for filling the crushed stone filter material layer.

[0013] Optionally, the landfill contains a landfill layer, and a cover layer covering the landfill layer is provided at the top of the landfill. The uppermost air duct extends to the top of the cover layer, and the uppermost support cage is filled with a clay layer, while the remaining parts of the support cage are filled with a gravel filter material layer.

[0014] Optionally, the uppermost air guide tube is an airtight solid-walled tube, while the remaining air guide tubes are permeable tubes with filter holes.

[0015] Optionally, the bottom of the landfill pit of the landfill is formed with alternating ridge-like protrusions and valley-like depressions, the air-guiding column unit is set at the top or middle of the ridge-like protrusions, and the bottom of the valley-like depressions is covered with drainage pipes.

[0016] Optionally, the grouting pile has a pre-reserved drain port that connects to the bottom air duct. Two adjacent drain ports are connected by a seepage pipe. The bottom of the landfill pit is provided with several layers of anti-seepage layer. The bottom of the valley depression is provided with several layers of drainage pipe. The seepage pipe is laid close to the anti-seepage layer.

[0017] This utility model has the following advantages and beneficial effects: 1. Through vertically arranged multi-section gas guide pipes and horizontally arranged gas collection pipes, the entire landfill area is fully covered within the filling site, increasing the collection radius and ensuring collection efficiency.

[0018] 2. Vertically installed multi-section gas guide pipes are supported by cast-in-place piles deeply embedded in the foundation to prevent the gas guide pipes from settling. At the same time, the support cage is supported on the cast-in-place piles to prevent the support cage and the crushed stone filter layer from settling. One end of the gas collection pipe passes through the support cage and is pre-embedded in the crushed stone filter layer. This can ensure that the gas can be collected and enter the gas guide pipes, and can also limit the settlement of the horizontally installed gas collection pipes to prevent the horizontal gas collection pipes from failing due to settlement and breakage. Attached Figure Description

[0019] Figure 1 This is a structural diagram of landfill waste in this utility model; Figure 2 This is a structural diagram of the gas discharge structure in this utility model installed inside the landfill pit; Figure 3 for Figure 2 A magnified view of a portion of point a. Figure 4 This is a structural diagram of the multi-section air guide pipe connected to the cast-in-place pile in this utility model; Figure 5 This is a cross-sectional view of the gas discharge structure of this utility model installed inside the landfill pit; Figure 6 for Figure 5 A cross-sectional view of a landfill pit filled with a layer of waste landfill material. Figure 7 for Figure 5 A cross-sectional view of a landfill pit filled with a waste landfill layer and covered with a capping layer; Figure 8 for Figure 5 A magnified view of a section at point b in the middle; Figure 9 for Figure 7 A magnified view of a section at point c in the middle; Figure 10 for Figure 7 A magnified view of a portion at point d in the middle; Figure 11 This is a structural diagram showing the connection between the air guide tube and the air guide connector in this utility model.

[0020] Attached reference numerals: 1-Foundation, 2-Imperile layer, 21-Drainage pipe, 3-Landfill layer, 31-Covering layer, 32-Clay layer, 4-Gas conduit, 41-Installation flange, 5-Support cage, 5a-Filling cavity, 5b-Gas collection cavity, 51-Outer steel mesh cage, 52-Inner steel mesh cage, 53-Crushed stone filter layer, 6-Cast-in pile, 61-Seepage pipe, 62-Extended air pipe, 63-Corrugated pipe, 64-Embedded steel pipe, 7-Gas transmission pipe, 71-Sampling and testing port. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this utility model, but not all embodiments.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0023] Example like Figures 1 to 11 As shown, a landfill gas discharge structure includes, Multiple air-guiding column units are installed at the bottom of the landfill pit.

[0024] The gas-conducting column unit includes a cast-in-place pile 6 deeply embedded in the foundation 1, and multiple sections of gas-conducting pipe 4 fixed to the top of the cast-in-place pile 6. The cast-in-place pile 6 is formed by drilling and casting at the bottom of the landfill pit. A support cage 5 is installed on the cast-in-place pile 6, which is fitted over the outside of the gas-conducting pipe 4, and the support cage 5 and the gas-conducting pipe 4 are coaxially arranged. The cast-in-place pile 6 serves as the bearing foundation for the gas-conducting pipe 4 and the support cage 5.

[0025] The support cage 5 is filled with a crushed stone filter material layer 53. Several air collection pipes are evenly distributed around the circumference of the support cage 5. One end of the air collection pipe passes through the support cage 5 and is embedded in the crushed stone filter material layer 53.

[0026] This invention utilizes vertically arranged multi-section gas guide pipes 4 and horizontally arranged gas collection pipes to fully cover the entire landfill area, increasing the collection radius and ensuring collection efficiency.

[0027] This invention uses cast-in-place piles 6 deeply embedded in the foundation 1 to support the vertically arranged multi-section air guide pipe 4, thus preventing the air guide pipe 4 from settling. At the same time, the support cage 5 is supported on the cast-in-place piles 6 to prevent the support cage 5 and the crushed stone filter layer 53 from settling. One end of the gas collecting pipe passes through the support cage 5 and is pre-embedded in the crushed stone filter layer 53. This not only ensures that the gas can be collected and enter the air guide pipe 4, but also limits the settlement of the horizontally arranged gas collecting pipe, preventing the horizontal gas collecting pipe from failing due to settlement and breakage.

[0028] like Figures 1 to 11As shown, the gas collection pipe includes a pre-embedded steel pipe 64, a corrugated pipe 63, and an extended air pipe 62. The pre-embedded steel pipe 64 is installed inside the support cage 5 and pre-embedded in the crushed stone filter material layer 53. The pre-embedded steel pipe 64 is fixed to the support cage 5 by welding. The outer end of the pre-embedded steel pipe 64 is connected to the corrugated pipe 63. One end of the corrugated pipe 63 is connected to the extended air pipe 62. The circumference of the extended air pipe 62 is evenly distributed with several filter holes, and a layer of geotextile is laid on the outside of the extended air pipe 62. The pre-embedded steel pipe 64 is welded to the support cage 5 to achieve stable fixation, avoiding the squeezing and settling of the crushed stone filter material layer 53 inside the support cage 5 from affecting the position of the pre-embedded steel pipe 64. At the same time, the pre-embedded steel pipe 64 and the extended air pipe 62 are connected by a corrugated pipe 63. When the landfill layer 3 settles, the corrugated pipe 63 can adapt to the deformation and settlement to achieve a stable and reliable connection, avoiding the vertical settlement of the extended air pipe 62 from causing the connection between it and the pre-embedded steel pipe 64 to break.

[0029] like Figure 5 and Figure 7 As shown, the extended vent pipe 62 has one section and is located at the high end of the landfill. The landfill is constructed with a high center and low sides, so only one section of the extended vent pipe 62 needs to be installed at the high center of the landfill.

[0030] like Figure 5 and Figure 7 As shown, the extended air pipe 62 consists of several sections. The diagram illustrates four sections of extended air pipe 62 connected sequentially, located at the lower end of the landfill. These sections are connected in pairs via corrugated pipes 63, and the extended air pipes at both ends are connected to pre-embedded steel pipes 64 on either side. In this design, at the lower part of the landfill, the distance between adjacent air pipes 4 is relatively large. Therefore, the use of multiple horizontally arranged extended air pipe sections 62, connected in pairs via corrugated pipes 63, allows for adaptive deformation and settlement, ensuring a stable and reliable connection. This prevents vertical settlement of the extended air pipes 62 from causing breakage in their connection to the pre-embedded steel pipes 64, while also guaranteeing effective long-distance air collection.

[0031] Furthermore, the pre-embedded steel pipe 64 has several filter holes evenly distributed around its circumference. The pre-embedded steel pipe 64 is a water-permeable and air-permeable steel pipe, which allows gas to pass through within the crushed stone filter layer 53, so as to guide the gas into the air guide pipe 4 more smoothly.

[0032] like Figures 1 to 11 As shown, the upper and lower ends of the air duct 4 are respectively provided with mounting flanges 41 for pipe docking, so as to realize the detachable connection of adjacent air ducts 4, and the detachable connection of air duct 4 and grouting pile 6.

[0033] like Figures 1 to 11As shown, the support cage 5 includes an outer steel mesh cage 51 and an inner steel mesh cage 52. A layer of geotextile is laid on the outside of the outer steel mesh cage 51. The inner steel mesh cage 52 is tightly attached to the outer wall of the mounting flange 41. The inner steel mesh cage 52 and the air guide pipe 4 form an air collection chamber 5b. The inner steel mesh cage 52 and the outer steel mesh cage 51 are spaced apart to form a filling chamber 5a for filling the crushed stone filter material layer 53. As a preferred embodiment, the filling chamber 5a is filled with the crushed stone filter material layer 53, while the air collection chamber 5b may be left unfilled to provide a flow cavity for the gas. Of course, the air collection chamber 5b may also be filled with a breathable filter layer, which allows gas to pass through and further enhances the support strength of the air guide pipe 4.

[0034] like Figures 1 to 11 As shown, the landfill contains a landfill layer 3, and a covering layer 31 is provided at the top of the landfill to cover the landfill layer 3, ensuring that the landfill can be reliably sealed and compacted after the waste is landfilled.

[0035] like Figures 1 to 11 As shown, the uppermost gas duct 4 extends to the upper side of the cover layer 31 and connects to the gas transmission pipe 7. The gas transmission pipe 7 is used to transport gas to external equipment, such as for direct combustion power generation, or as fuel for boilers or industrial kilns. The gas transmission pipe 7 is equipped with a sampling and detection port 71, allowing operators to conveniently and safely perform gas sampling and real-time online monitoring.

[0036] like Figure 9 As shown, the uppermost support cage 5 is filled with a clay layer 32, while the remaining parts of the support cage 5 are filled with a gravel filter material layer 53. The clay layer 32 is used to achieve compaction and sealing of the upper layer, preventing gas leakage. Together with the covering layer 31 on the clay layer 32, a reliable seal is achieved.

[0037] like Figure 9 As shown, the uppermost gas guide pipe 4 is an airtight solid-walled pipe. This section of the gas guide pipe 4 is located between the upper cover layer 31 and the clay layer 32, and mainly serves to transport gas. The remaining part of the gas guide pipe 4 is a permeable pipe with filter holes. This part of the gas guide pipe 4 is buried in the landfill layer 3 and serves to transport gas and guide the gas in the landfill layer 3 into the gas guide pipe 4.

[0038] like Figures 1-10 As shown, the bottom of the landfill pit forms alternating ridge-like protrusions and valley-like depressions. Air-guiding column units are located at the top or middle of the ridge-like protrusions, and drainage pipes 21 are laid at the bottom of the valley-like depressions. Positioning the air-guiding column units at a relatively high location facilitates the natural drainage of seepage water from the bottom side of the unit, achieving gas-liquid separation.

[0039] like Figures 1-10As shown, a drainage port connected to the bottom air duct 4 is reserved inside the cast-in-place pile 6. Adjacent drainage ports are connected by a seepage pipe 61. This allows the seepage water that eventually flows into the bottom of the air duct 4 to be naturally drained through the seepage pipe 61 into the drainage pipe 21 at the bottom of the foundation pit. Several layers of impermeable layers 2 are provided at the bottom of the foundation pit. These impermeable layers 2 can be composed of geotextile, HDPE membrane, etc. Several layers of drainage pipes 21 are installed at the bottom of the valley-shaped depression, with the seepage pipes 61 laid tightly against the impermeable layers 2. Through the drainage pipes 21, the seepage water is ultimately guided, collected, and discharged.

[0040] In this invention, waste needs to be stacked in layers when filling it. For example... Figure 6 As shown, for each section of the air duct 4 installed, a corresponding section of the support cage 5 is installed, and then a layer of landfill 3 is filled. After filling a layer of landfill 3, an air collection pipe (pre-embedded steel pipe 64, corrugated pipe 63, and extended air pipe 62) is installed on top of it. In this way, the layers are stacked and compacted until the final covering layer 31 is covered.

[0041] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A landfill gas discharge structure, characterized in that: include, Multiple air-guiding column units are installed at the bottom of the landfill pit; The air-guiding column unit includes a cast-in-place pile deeply embedded in the foundation, and multiple sections of air-guiding pipe fixed to the top of the cast-in-place pile; a support cage is provided on the cast-in-place pile, and the support cage is sleeved on the outside of the air-guiding pipe. The support cage is filled with a layer of crushed stone filter material, and several air collection pipes are evenly distributed around the circumference of the support cage. One end of each air collection pipe passes through the support cage and is embedded in the crushed stone filter material layer.

2. The landfill gas drainage structure according to claim 1, characterized in that: The gas collection pipe includes a pre-embedded steel pipe, a corrugated pipe, and an extended gas pipe. The pre-embedded steel pipe is installed in the support cage and pre-embedded in the crushed stone filter material layer. The pre-embedded steel pipe is connected to the corrugated pipe. One end of the corrugated pipe is connected to the extended gas pipe. The extended gas pipe has several filter holes evenly distributed around its circumference.

3. The landfill gas drainage structure according to claim 2, characterized in that: The extended air pipe has one section and is located at the high end of the landfill.

4. The landfill gas drainage structure according to claim 2, characterized in that: The extended air pipe is provided in several sections and is located at the lower end of the landfill. The several sections of the extended air pipe are connected by corrugated pipes, and the extended air pipes at both ends are respectively connected to the pre-buried steel pipes on both sides.

5. The landfill gas drainage structure according to claim 2, characterized in that: The pre-embedded steel pipe has several filter holes evenly distributed around its circumference.

6. The landfill gas drainage structure according to claim 1, characterized in that: The upper and lower ends of the air guide pipe are respectively provided with mounting flanges for pipe connection; the support cage includes an outer steel mesh cage and an inner steel mesh cage. The inner steel mesh cage is tightly attached to the outer wall of the mounting flange. The inner steel mesh cage and the air guide pipe form an air collection cavity. The inner steel mesh cage and the outer steel mesh cage are spaced apart to form a filling cavity for filling the crushed stone filter material layer.

7. The landfill gas drainage structure according to claim 6, characterized in that: The landfill contains a landfill layer, and a cover layer is provided at the top of the landfill to cover the landfill layer. The air duct at the top extends to the top of the cover layer. The support cage at the top is filled with a clay layer, and the rest of the support cage is filled with a gravel filter material layer.

8. The landfill gas drainage structure according to claim 7, characterized in that: The uppermost air guide tube is an airtight solid-walled tube, while the remaining air guide tubes are permeable tubes with filter holes.

9. The landfill gas drainage structure according to claim 7, characterized in that: The bottom of the landfill pit of the landfill site has alternating ridge-like protrusions and valley-like depressions. The air-guiding column unit is set at the top or middle of the ridge-like protrusions, and a drainage pipe is laid at the bottom of the valley-like depressions.

10. The landfill gas discharge structure according to claim 9, characterized in that: The grouting pile has a pre-reserved drainage port that connects to the bottom air duct. Adjacent drainage ports are connected by seepage pipes. The bottom of the landfill pit is provided with several layers of anti-seepage layer. The bottom of the valley depression is provided with several layers of drainage pipes. The seepage pipes are laid close to the anti-seepage layer.

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