Landfill gas collecting well

Abstract

The utility model discloses a garbage landfill gas collecting well which comprises a well hole vertically penetrating through a garbage landfill layer, a vertical gas collecting pipe is arranged in the center of the well hole, the bottom of the well hole extends to the bottom of a percolate flow guide layer, and a gravel layer, a coarse sand layer, a sand and bentonite mixing layer and a concrete layer are sequentially arranged in the well hole from bottom to top. The gas collecting pipe sequentially comprises a gas suction section, a telescopic section and a gas collecting section from bottom to top, the rubble layer is higher than the upper edge of the telescopic section, a gas collecting hood is arranged at the bottom of the gas suction section, the distance between the bottom of the gas collecting hood and the top of the percolate flow guide layer is 30-40 cm, and gas suction holes are evenly distributed in the side wall of the gas suction section. The landfill gas collecting well has the advantages of being high in guiding and discharging efficiency, good in sealing performance, high in reliability, high in safety and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of garbage disposal, in particular to a landfill gas collection well. Background Art

[0002] After a period of time of landfilling of domestic waste, due to the decomposition of microorganisms, the garbage pile will produce a large amount of combustible landfill gas with a pungent odor, which has hidden dangers such as flammability, explosion and environmental pollution. Therefore, domestic waste landfills must establish a landfill gas drainage system to guide the gas in the landfill layer for utilization, incineration or direct discharge after meeting the emission requirements during the operation period and subsequent maintenance and management period of the landfill, so as to eliminate the combustion and explosion hazards of combustible gases and reduce greenhouse gas emissions.

[0003] The existing landfill gas collection wells have low landfill gas collection efficiency and incomplete landfill gas filtration, which may cause fine garbage particles to block the gas collection pipe. At the same time, under the influence of landfill sedimentation pressure, the landfill gas collection pipe is prone to deformation and damage, and cannot effectively achieve gas drainage, posing a safety hazard. Utility Model Content

[0004] The utility model aims to provide a landfill gas collection well to solve the problems existing in the prior art.

[0005] The purpose of the utility model is achieved as follows: A landfill gas collection well, including a well hole that vertically passes through a landfill layer, a vertical gas collecting pipe is arranged in the center of the well hole, the bottom of the well hole extends to the bottom of a leachate diversion layer, and a crushed stone layer, a coarse sand layer, a mixed layer of sand and bentonite, and a concrete layer are arranged in the well hole from bottom to top. The gas collecting pipe includes an air suction section, a telescopic section and a gas collecting section from bottom to top. The height of the crushed stone layer is higher than the upper edge of the telescopic section. The bottom of the air suction section is provided with an air collecting hood, and the bottom of the air collecting hood is 30-40 cm away from the top of the leachate diversion layer. Air suction holes are evenly distributed on the side wall of the air suction section.

[0006] The landfill gas collection well of the utility model improves the gas drainage efficiency through the gas collecting hood and the air suction hole, and the bottom of the gas collecting hood is a certain distance away from the leachate diversion layer, and the fine garbage particles in the gas can be effectively filtered through the gravel layer to prevent the gas collecting pipe from being blocked, and avoid the possibility that the leachate in the leachate diversion layer does not enter the leachate drainage pipe but enters the gas collecting pipe, further avoiding the blockage of the gas collecting pipe. And through the layered filling in the entrance hole, effective sealing is achieved to avoid the overflow of landfill gas. At the same time, by setting a telescopic section using an elastic pipeline in the gas collecting pipe, it is helpful to withstand the pressure of the settlement of the landfill and avoid deformation and damage of the gas collecting pipe. In summary, the landfill gas collection well of the utility model has the advantages of high drainage efficiency, good sealing, strong reliability, and high safety.

[0007] As a further improvement of the utility model, the upper end of the gas collecting pipe extends out from the wellbore and is connected to a gas collecting and conveying pipeline, which is connected to the gas purification equipment through an induced draft fan, so that the landfill gas can be actively extracted and discharged through the induced draft fan, thereby improving the gas collecting efficiency.

[0008] As a further improvement of the utility model, the length of the suction section is not less than 2 / 3 of the total length of the gas collecting pipe, which improves the gas collecting efficiency. Even in the case of unfavorable leachate drainage, the landfill gas collection channel will not be blocked, thereby improving the reliability of landfill gas drainage.

[0009] As a further improvement of the present invention, the diameter of the air intake holes is 1-2 cm, the air intake holes are arranged in layers, the number of air intake holes in each layer is 4 and the spacing between the air intake holes in adjacent layers is 15-20 cm, so as to improve the air collection efficiency and ensure the smoothness of the exhaust.

[0010] As a further improvement of the utility model, the crushed stone layer is filled with washed gravel with a particle size of 2.5-5 cm, which ensures the filtering effect on the landfill gas while avoiding affecting the smoothness of the landfill gas discharge.

[0011] As a further improvement of the utility model, a non-woven geotextile is laid between the crushed stone layer and the coarse sand layer to further intercept fine garbage particles in the rising landfill gas.

[0012] As a further improvement of the utility model, the thickness of the concrete layer and the coarse sand filter layer is 30 cm, and the thickness of the sand and bentonite mixed layer is 100 cm, which effectively absorbs water vapor in the landfill gas and realizes effective sealing.

[0013] As a further improvement of the utility model, the diameter of the well hole is 90-100 cm, and the diameter of the gas collecting pipe is 10-20 cm, so that the influence radius of the collection well can reach 90 m. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of a landfill gas collection well of the utility model.

[0015] Among them, 1 is the landfill layer, 2 is the leachate diversion layer, 3 is the crushed stone layer, 4 is the coarse sand layer, 5 is the mixed layer of sand and bentonite, 6 is the concrete layer, 7 is the air intake section, 8 is the expansion section, 9 is the gas collection section, 10 is the air intake hole, 11 is the induced draft fan, and 12 is the gas purification equipment. DETAILED DESCRIPTION

[0016] like Figure 1The landfill gas collection well shown includes a well hole that vertically passes through the landfill layer 1, and the bottom of the well hole extends to the bottom of the leachate diversion layer 2. In the well hole, there are a crushed stone layer 3, a coarse sand layer 4, a sand and bentonite mixed layer 5, and a concrete layer 6 from bottom to top. The crushed stone layer 3 is filled with washed gravel with a particle size of 2.5-5 cm, which ensures the filtering effect on the landfill gas while avoiding affecting the smoothness of the landfill gas drainage. A non-woven geotextile is laid between the crushed stone layer 3 and the coarse sand layer 4 to further intercept the fine garbage particles in the rising landfill gas. The thickness of the concrete layer 6 and the coarse sand filter layer is 30 cm, and the thickness of the sand and bentonite mixed layer 5 is 100 cm, which effectively absorbs the water vapor in the landfill gas and achieves effective sealing.

[0017] A vertical gas collecting pipe is provided in the center of the well hole. The gas collecting pipe includes an air suction section 7, a telescopic section 8 and a gas collecting section 9 from bottom to top. The height of the gravel layer 3 is higher than the upper edge of the telescopic section 8. The length of the air suction section 7 is not less than 2 / 3 of the total length of the gas collecting pipe, which improves the gas collection efficiency, and even in the case of unfavorable drainage of the leachate, it will not cause the landfill gas collection channel to be blocked, thereby improving the reliability of the landfill gas drainage. The bottom of the air suction section 7 is provided with an air collecting hood, and the bottom of the air collecting hood is 30-40 cm away from the top of the leachate diversion layer 2, and the side walls of the air suction section 7 are evenly distributed with air suction holes 10. In this embodiment, the diameter of the well hole is 90-100 cm, and the diameter of the gas collecting pipe is 10-20 cm, which can make the influence radius of the collection well reach 90 m. The diameter of the air intake holes 10 is 1-2 cm, and the air intake holes 10 are arranged in layers, with 4 air intake holes 10 in each layer and the spacing between the air intake holes 10 in adjacent layers is 15-20 cm, which improves the gas collection efficiency and ensures the smoothness of the drainage. The upper end of the gas collection pipe extends from the well hole and is connected to a gas collection and transportation pipeline, which is connected to the gas purification equipment 12 through the induced draft fan 11, so that the active extraction and drainage of landfill gas can be achieved through the induced draft fan 11, thereby improving the gas collection efficiency.

[0018] The landfill gas collection well of the present embodiment improves the gas drainage efficiency through the gas collecting hood and the air suction hole 10, and the bottom of the gas collecting hood is a certain distance away from the leachate diversion layer 2. The gravel layer 3 can effectively filter the fine garbage particles in the gas to prevent the gas collecting pipe from being blocked, and avoid the possibility that the leachate in the leachate diversion layer does not enter the leachate drainage pipe but enters the gas collecting pipe, further avoiding the blockage of the gas collecting pipe. And through the layered filling in the entrance hole, effective sealing is achieved to avoid the overflow of landfill gas. At the same time, by setting the telescopic section 8 using an elastic pipeline in the gas collecting pipe, it is helpful to withstand the pressure of the settlement of the landfill and avoid deformation and damage of the gas collecting pipe. In summary, the landfill gas collection well of the present embodiment has the advantages of high drainage efficiency, good sealing, strong reliability, and high safety.

[0019] The present utility model is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present utility model, technicians in this field can make some substitutions and deformations to some technical features therein according to the disclosed technical content without creative labor, and these substitutions and deformations are all within the protection scope of the present utility model.

Claims

1. A landfill gas collection well, comprising a well hole vertically passing through a landfill layer, wherein a vertical gas collecting pipe is provided in the center of the well hole, characterized in that: The bottom of the well hole extends to the bottom of the leachate diversion layer. A gravel layer, a coarse sand layer, a sand and bentonite mixed layer, and a concrete layer are arranged in the well hole from bottom to top. The gas collecting pipe includes an air suction section, a telescopic section, and an air collecting section from bottom to top. The height of the gravel layer is higher than the upper edge of the telescopic section. The bottom of the air suction section is provided with an air collecting hood. The bottom of the air collecting hood is 30-40 cm away from the top of the leachate diversion layer. Air suction holes are evenly distributed on the side wall of the air suction section.

2. The landfill gas collection well according to claim 1, characterized in that: The upper end of the gas collecting pipe extends out from the well hole and is connected to a gas collecting and conveying pipeline, and the gas collecting and conveying pipeline is connected to the gas purification equipment through an induced draft fan.

3. The landfill gas collection well according to claim 1, characterized in that: The length of the air intake section is not less than 2 / 3 of the total length of the air collecting pipe.

4. The landfill gas collection well according to claim 1, characterized in that: The diameter of the air intake holes is 1-2 cm, and the air intake holes are arranged in layers, the number of air intake holes in each layer is 4, and the spacing between the air intake holes in adjacent layers is 15-20 cm.

5. The landfill gas collection well according to claim 1, characterized in that: The crushed stone layer is filled with washed gravel with a particle size of 2.5-5 cm.

6. The landfill gas collection well according to claim 1, characterized in that: A non-woven geotextile is laid between the crushed stone layer and the coarse sand layer.

7. The landfill gas collection well according to claim 1, characterized in that: The thickness of the concrete layer and the coarse sand filter layer is 30 cm, and the thickness of the sand and bentonite mixed layer is 100 cm.

8. The landfill gas collection well according to any one of claims 1 to 5, characterized in that: The diameter of the well hole is 90-100 cm, and the diameter of the gas collecting pipe is 10-20 cm.

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