AU2021102242A4 - Underground greenhouse gas acquisition apparatus - Google Patents

Abstract

The utility model belongs to the technical field of soil environment detection, and discloses an underground greenhouse gas acquisition apparatus, including an acquisition tube horizontally arranged in the stratum. Both ends of the acquisition tube are open and are respectively provided with a sealing cap and an acquiring cap with a gas pipe, one end of the gas pipe extends into the acquisition tube, and the other end of the gas pipe extends out of the ground and is equipped with a Luer female connector. The wall of the acquisition tube close to the sealing cap is circumferentially provided with first vent holes and is also horizontally and symmetrically provided with two rows of extending holes. Two pushing plates are provided in the acquisition tube, and acquisition syringes are fixedly connected to the pushing plates, where one end of the acquisition syringe far away from a needle tip is connected to the acquisition tube. The acquisition syringe is slidably connected in the extending hole, the two pushing plates drive the acquisition syringes to extend out of the acquisition tube through a spreading structure, and the acquisition syringes are provided with second vent holes. The acquisition syringes extend out of the acquisition tube and are inserted into the soil, increasing a contact area between the acquisition tube and the soil, thereby increasing a ventilation area, and improving soil gas collection efficiency of the acquisition tube

Description

I UNDERGROUND GREENHOUSE GAS ACQUISITION APPARATUS TECHNICAL FIELD

[01] The utility model relates to the technical field of soil environment detection, and in particular, to an underground greenhouse gas acquisition apparatus.

BACKGROUNDART

[02] Soil as a porous medium contains a large amount of greenhouse gas in the air stored in its voids. As one of the important components of soil, the greenhouse gas in the soil is of great significance to plant growth and soil formation. The composition and concentration of greenhouse gas in the soil vary at different depths. At present, soil gas at different depths can be acquired by inserting several acquisition tubes of different lengths vertically into the soil, and acquiring, through a vent hole provided at the bottom of the acquisition tube, the soil gas at different depths reached by the vent holes. However, there is a big problem with the foregoing apparatus and its arrangement method: the soil air above the vent hole of the acquisition tube is likely to flow along the wall of the acquisition tube to the vent hole. As a result, the finally acquired soil gas includes not only the soil gas at the depth reached by the vent hole, and cannot accurately reflect the soil gas components at this depth.

[03] To solve this problem, the utility model patent entitled "SIMPLE DEEP SOIL GAS SAMPLER AND SAMPLING METHOD THEREOF" with the patent number "201710127750.9" uses a gas acquisition tube, where one end of the gas acquisition tube is closed, and the other end is connected to a gas duct, and two groups of straightly arranged vent holes are arranged on both sides of the gas acquisition tube. The gas acquisition tubes are placed horizontally in soil at different depths to acquire soil gas at different depths. Unlike vertical placement, the horizontal placement can prevent the upper soil gas from getting into the inside of the vent hole along the tube wall. However, there are still some problems with this gas acquisition tube: through holes are provided only on both sides of the tube wall, the ventilation area is insufficient, the ventilation efficiency is low, and consequently, the soil gas cannot be effectively collected.

SUMMARY

[04] To solve the above technical problems, the utility model provides an underground greenhouse gas acquisition apparatus, where first vent holes are provided in the wall of an acquisition tube, acquisition syringes that can extend out of the acquisition tube are provided on both sides of the acquisition tube, and second vent holes are provided on the acquisition syringes. After the acquisition tube is placed horizontally in soil, the acquisition syringes extend out of the acquisition tube and are inserted into the soil, increasing a contact area between the acquisition tube and the soil. Soil gas is acquired through the first vent holes and the second vent holes, thereby significantly improving the gas collection efficiency.

[05] To achieve the above objectives, the utility model provides the following solution: The utility model provides an underground greenhouse gas acquisition apparatus, including an acquisition tube horizontally arranged in the stratum, where both ends of the acquisition tube are open and are respectively provided with a sealing cap and an acquiring cap with a gas pipe, one end of the gas pipe extends into the acquisition tube, and the other end of the gas pipe extends out of the ground and is equipped with a Luer female connector in communication with a gas collection mechanism; the wall of the acquisition tube close to the sealing cap is circumferentially provided with first vent holes, and is also horizontally and symmetrically provided with two rows of extending holes; two pushing plates are provided in the acquisition tube, acquisition syringes are fixedly connected to the pushing plates, one end of the acquisition syringe far away from a needle tip is connected to the acquisition tube, the acquisition syringe is slidably connected in the extending hole, the two pushing plates drive the acquisition syringes to extend out of the acquisition tube through a spreading structure, and the acquisition syringes are provided with second vent holes.

[06] Preferably, the spreading structure includes a double-sided rack, toggle blocks, and guide rings fixedly connected to an inner wall of the acquisition tube, where the double-sided rack is slidably connected to the guide rings, and an end head of the double-sided rack is provided with a pull handle; one end of the toggle block is provided with a gear meshing with the double-sided rack, and the other end of the toggle block is rotatably connected to the pushing plate.

[07] Preferably, the acquisition syringe includes a tapered section and a cylindrical section, the cylindrical section is circumferentially provided with the second vent holes, and an outer cylinder wall of the cylindrical section is closely attached to a hole wall of the extending hole.

[08] Preferably, the pushing plate is a curved panel, and a surface of the curved panel can be closely attached to an inner wall of the acquisition tube.

[09] Preferably, an outer wall of the acquisition tube in which the first vent holes are located is covered with a screen.

[10] Preferably, the screen is sleeved with a fastening strap.

[11] Preferably, a waterproof gas-permeable membrane is attached to an inner wall of the acquisition tube in which the first vent holes are located.

[12] Preferably, a waterproof gas-permeable membrane is attached to an inner wall of the acquisition syringe in which the second vent holes are located.

[13] Preferably, the gas pipe is a rubber hose.

[14] Preferably, support rings are spaced apart in the gas pipe.

[15] Compared with the prior art, the utility model achieves the following technical effects:

[16] 1. The wall of the acquisition tube close to the sealing cap is circumferentially provided with the first vent holes and is also horizontally and symmetrically provided with two rows of extending holes for the acquisition syringes to extend out. When the acquisition tube is inserted into the soil horizontally, the acquisition syringes extend out of the extending holes under the action of the spreading structure and horizontally insert into the soil on both sides. Through the second vent holes, a ventilation area with the soil on both sides is increased, thereby increasing the soil gas collection efficiency. In addition, because the acquisition syringes and the acquisition tube are at the same soil depth, the gas acquired by the acquisition syringes does not affect the soil air composition at this depth, ensuring accuracy of the greenhouse gas composition and concentration of the acquired soil gas.

[17] 2. The spreading structure uses the double-sided rack and the toggle block that work cooperatively. When the double-sided rack is pulled outwards, the toggle block can simply and quickly push the acquisition syringes out of the acquisition tube. The double-sided rack continues to be pulled until it is pulled out of the acquisition tube. This minimizes the space occupied by the spreading structure in the acquisition tube.

[18] 3. The outer wall of the acquisition tube in which the first vent holes are located is covered with a screen. The screen can effectively prevent soil particles from entering the acquisition tube and blocking the first vent holes, and can also prevent animals and insects in the soil from entering the acquisition tube through the first vent holes.

[19] 4. A waterproof gas-permeable membrane is attached to the inner wall of the acquisition tube in which the first vent holes are located. The waterproof gas-permeable membrane can prevent water vapor in the soil from entering the acquisition tube and staying in the acquisition tube to form water which in turn affects gas collection, thereby avoiding a risk of water being extracted with the gas pipe during gas extraction. The waterproof gas-permeable membrane also plays a role in preventing soil particles from entering the acquisition tube.

[20] 4. A waterproof gas-permeable membrane is attached to the inner wall of the acquisition syringe in which the second vent holes are located. The waterproof gas-permeable membrane can prevent water vapor in the soil from entering the acquisition syringe and staying in the acquisition syringe to form water, and can also prevent soil particles from entering the acquisition syringe.

[21] 5. The support rings are spaced apart in the gas pipe. The support rings support the gas pipe from the inside, which can avoid impact on the gas transmission efficiency by preventing the soil around the gas pipe from squeezing and deforming the gas pipe after the acquisition tube is buried into the soil.

BRIEF DESCRIPTION OF THE DRAWINGS

[22] To describe the technical solutions in embodiments of the utility model or in the prior art more clearly, the accompanying drawings to be used in the embodiments are briefly introduced below. Apparently, the accompanying drawings in the following description show merely some embodiments of the utility model, and a person of ordinary skill in the art can still derive other accompanying drawings from these accompanying drawings without inventive efforts.

[23] FIG. 1 is a schematic diagram of an overall structure of an acquisition tube.

[24] FIG. 2 is a schematic diagram of a local structure of an acquisition tube.

[25] FIG. 3 is a top view of a spreading structure.

[26] FIG. 4 is a schematic diagram of a local structure of a spreading structure.

[27] Reference signs: 1. acquisition tube; 2. sealing cap; 3. acquiring cap; 4. gas pipe; 5. first vent hole; 6. second vent hole; 7. extending hole; 8. pushing plate; 9. acquisition syringe; 10. double-sided rack; 11. pull handle; 12. toggle block; 13. guide ring; 14. rotating shaft; and 15. pushing plate connection block.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[28] A clear and complete description of the technical solutions in the embodiments of the utility model will be given below, in combination with the accompanying drawings in the embodiments of the utility model. Apparently, the embodiments described below are a part, but not all, of the embodiments of the utility model. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the utility model without inventive efforts fall within the protection scope of the utility model.

[29] An embodiment provides an underground greenhouse gas acquisition apparatus. As shown in FIG. 1 to FIG. 4, the apparatus includes an acquisition tube1 horizontally arranged in the stratum. Both ends of the acquisition tube 1 are open and are respectively equipped with a sealing cap 2 and an acquiring cap 3. The acquiring cap 3 is provided with a small hole for a gas pipe 4 to extend into. One end of the gas pipe 4 extends into the acquisition tube 1 through the small hole, the other end extends out of the ground, and an end head of the gas pipe 4 is equipped with a Luer female connector for in communication with a gas collection mechanism. The wall of the acquisition tube 1 close to the sealing cap 2 is circumferentially provided with first vent holes 5 and is also horizontally and symmetrically provided with two rows of extending holes 7 on both sides. Two pushing plates 8 are provided in the acquisition tube 1. Acquisition syringes 9 with the same quantity and positions as the extending holes 7 are fixedly connected to the pushing plates 8, and the acquisition syringe 9 is slidably connected in the extension hole 7. An end of the acquisition syringe 9 far away from a needle tip is open and communicates with the acquisition tube 1. The acquisition syringe 9 is provided with second vent holes 6. Soil gas can enter the acquisition syringe 9 through the second vent holes 6, and then enter the acquisition tube 1 from the open end of the acquisition syringe 9. The acquisition tube 1 is provided with a spreading mechanism. The two pushing plates 8 can be pushed through the spreading structure, and then the two pushing plates 8 separately drive the acquisition syringes 9 to slide outward through the extending holes 7 and then extend out of the acquisition tube 1. To use the underground greenhouse gas acquisition apparatus, an operator needs to dig a soil profile, drill holes in the profile horizontally at a predetermined depth, insert the acquisition tube 1 into the hole, and make the extending holes 7 horizontal to the soil on both sides. After the acquisition tube 1 is inserted in place, the operator pushes the pushing plates 8 through the spreading mechanism, so that the acquisition syringes 9 extend out of the extending holes 7 and horizontally insert into the soil on both sides of the acquisition tube 1. The spreading action ends after the pushing plates 8 are completely attached to an inner wall of the acquisition tube 1. After the acquisition syringes 9 are inserted into the soil on both sides, a contact area between the acquisition tube 1 and the soil can be increased, thereby increasing a ventilation area and improving gas collection efficiency. In addition, because the acquisition syringes 9 are inserted horizontally into the soil on both sides, their depths are within the range of the soil depth of the acquisition tube 1, without bringing the soil gas above the acquisition tube 1 into this depth, thereby avoiding impact on the greenhouse gas composition and concentration in the acquired gas. To acquire gas, the operator only needs to open the Luer female connector and connect a three-way valve of the gas collection mechanism. After the gas is acquired, the operator only needs to cover the Luer female connector with its cap. The operations are simple and fast. Then, within 24 hours after the gas is extracted, the acquired samples are analyzed with a gas chromatograph to obtain greenhouse gas concentration.

[30] As shown in FIG. 3 and FIG. 4, in this embodiment, the spreading structure includes a double-sided rack 10, toggle blocks 12, and guide rings 13, and the guide rings 13 are fixedly connected to the inner wall of the acquisition tube 1. In this embodiment, two guide rings 13 are used and respectively arranged on the inner wall of the acquisition tube 1 close to the sealing cap 2 and the inner wall of the acquisition tube 1 close to the acquiring cap 3 (certainly, there may be another quantity of guide rings 13 as long as they can effectively guide the double sided rack 10), the double-sided rack 10 is slidably connected in the guide rings 13, and an end head of the double-sided rack 10 is provided with a pull handle 11 for pulling the double-sided rack 10 outwards. There are at least two toggle blocks 12, which are symmetrically arranged on both sides of the double-sided rack 10. One end of the toggle block 12 is provided with a gear, the gear is meshed with the double-sided rack 10, and the other end of the toggle block 12 is rotatably connected to the pushing plate 8. Before the double-sided rack 10 is pulled, there is an included angle between the toggle block 12 and the double-sided rack 10, and an end of the toggle block 12 rotatably connected to the pushing plate 8 faces towards the acquiring cap. When the double-sided rack 10 is being pulled outward, the toggle blocks 12 rotate around the pushing plates 8 and push the pushing plates 8 to both sides of the acquisition tube 1.

[31] Further, as shown in FIG. 3 to FIG. 4, in this embodiment, four toggle blocks 12 are used, every two of which form a group and are symmetrically meshed on both sides of the double-sided rack 10. The other end of the toggle block 12 is rotatably connected to the pushing plate 8 through a rotating shaft 14. Specifically, the two pushing plates 8 are provided with four pushing plate connection blocks 15, where two pushing plate connection blocks 15 form a group and are symmetrically arranged up and down on a surface of the pushing plate 8. Then, the rotating shaft 14 is vertically installed between the two pushing plate connection blocks 15, and an end head of the toggle block 12 is also located between the two pushing plate connection blocks 15 and rotatably connected to the rotating shaft 14. After the acquisition tube 1 is inserted into the holes in the soil profile, the operator presses the wall of the acquisition tube 1 with a hand or foot, and then pulls the pull handle 11 outwards by hand. The double-sided rack 10 moves outwards and brings the ends of the toggle blocks 12 with a gear to move outwards, so that the toggle blocks 12 rotate around the rotating shafts 14 as a whole and push the pushing plates 8 towards both sides of the acquisition tube 1. The pushing plates 8 drive the acquisition syringes 9 to slide outwards from the extending holes 7, and finally extend out of the acquisition tube 1 and insert into the soil on both sides of the acquisition tube 1. When the pushing plates 8 are attached to the inner wall of the acquisition tube 1, the double-sided rack 10 continues to be pulled until it is pulled out of the acquisition tube 1. Then the operator covers the acquisition tube 1 with the acquiring cap 3 to complete arrangement of one acquisition tube 1.

[32] As shown in FIG. 1 to FIG. 4, in this embodiment, the acquisition syringe 9 includes a tapered section and a cylindrical section. When the acquisition syringe 9 extends outwards, a tapered tip of the tapered section faces towards the soil on one side of the acquisition tube 1. The sharp tapered tip can be easily inserted into the soil, reducing the resistance of inserting the acquisition syringe 9 into the soil. In this way, the acquisition syringe 9 can be inserted into the soil more smoothly, reducing the resistance of manually pulling the double-sided rack 10. The cylindrical section is circumferentially provided with the second vent holes 6. Through the second vent holes 6, a ventilation area with the soil is increased, improving the soil gas collection effect. In addition, an outer cylinder wall of the cylindrical section is closely attached to a hole wall of the extending hole 7, enabling the acquisition syringe 9 to extend straight out of the extending hole 7. This prevents the acquisition syringe 9 from swaying in the extending hole 7 and being inserted into the soil obliquely.

[33] In this embodiment, the pushing plate 8 is a curved panel, and a surface of the curved panel matches a shape of the inner wall of the acquisition tube 1. After the pushing plate 8 is pushed to the inner wall of the acquisition tube 1, the surface of the pushing plate 8 can be closely attached to the inner wall of the acquisition tube 1, ensuring that a gap between the bottom of the acquisition syringe 9 and the extending hole 7 is sealed by the surface of the push plate 8.

[34] In this embodiment, an outer wall of the acquisition tube 1 in which the first vent holes 5 are located is covered with a screen. The screen can prevent soil particles from entering the acquisition tube 1 or blocking the first vent holes 5, and can also prevent living beings in the soil from getting stuck in the first vent holes 5 or entering the acquisition tube 1.

[35] Further, a metal screen is used in this embodiment. The metal screen can effectively prevent living beings in the soil from gnawing and destroying the screen.

[36] Further, to prevent the screen from sliding, the screen is fastened to the outer wall of the acquisition tube 1 by using a fastening strap.

[37] In this embodiment, the outer wall of the acquisition syringe 9 in which the second vent holes 6 are located is covered with a screen. The screen can prevent soil particles from blocking the second vent holes 6 or entering the acquisition syringe 9 and can also prevent living beings in the soil from getting stuck in the second vent holes 6 or entering the acquisition syringe 9. In this case, the cylinder wall of the acquisition syringe 9 is closely attached to the extending hole 7 after being covered with the screen.

[38] In this embodiment, a waterproof gas-permeable membrane is attached to the inner wall of the acquisition tube 1 in which the first vent holes 5 are located. The waterproof gas permeable membrane allows soil gas to enter while preventing water vapor from entering the acquisition tube 1 and forming water in the acquisition tube 1. During gas collection, the water is extracted out of the acquisition tube 1 through the gas pipe 4.

[39] Further, in this embodiment, a waterproof gas-permeable membrane is attached to the inner wall of the acquisition syringe 9 in which the second vent holes 6 are located.

[40] In this embodiment, the gas pipe 4 is a rubber hose. After the soil profile is buried, a length of the gas pipe 4 protruding from the ground is at least 100 mm, which can be easily noticed by the staff and protect the gas pipe 4 from being stepped on by the staff during sampling.

[41] Further, in this embodiment, support rings are spaced apart in the gas pipe 4. The support rings can support the gas pipe 4 from the inside, preventing the gas pipe 4 from being squeezed and deformed by the soil and affecting air extraction efficiency.

[42] In this embodiment, the acquisition tube 1 is made of a plastic cylinder with a length of 500 mm and an inner diameter of 18 mm. The first vent holes 5 with a diameter of 3 mm allow gases to freely exchange inside and outside the acquisition tube 1. An end of the gas pipe 4 is equipped with a Luer female connector with a cap. A three-way valve of the syringe can be connected to the Luer female connector. Each time 100 ml of gas is extracted with the syringe. After the sample is acquired, the operator closes the three-way valve, pulls it out, and covers the Luer female connector with its cap. Then within 24 hours after the gas is extracted, the sample is analyzed with a gas chromatograph to obtain the greenhouse gas concentration and composition.

[43] Several examples are used for illustration of the principles and implementation methods of the utility model. The description of the embodiments is used to help illustrate the method and its core principles of the utility model. In addition, a person of ordinary skill in the art can make various modifications in terms of specific embodiments and scope of application in accordance with the teachings of the utility model. In conclusion, the content of this specification shall not be construed as a limitation to the utility model.

Claims (10)

WHAT IS CLAIMED IS:

1. An underground greenhouse gas acquisition apparatus, comprising an acquisition tube horizontally arranged in the stratum, wherein both ends of the acquisition tube are open and are respectively provided with a sealing cap and an acquiring cap with a gas pipe, one end of the gas pipe extends into the acquisition tube, and the other end of the gas pipe extends out of the ground and is equipped with a Luer female connector in communication with a gas collection mechanism; the wall of the acquisition tube close to the sealing cap is circumferentially provided with first vent holes, and is also horizontally and symmetrically provided with two rows of extending holes; two pushing plates are provided in the acquisition tube, and acquisition syringes are fixedly connected to the pushing plates, wherein one end of the acquisition syringe far away from a needle tip is connected to the acquisition tube; the acquisition syringe is slidably connected in the extending hole, the two pushing plates drive the acquisition syringes to extend out of the acquisition tube through a spreading structure, and the acquisition syringes are provided with second vent holes.

2. The underground greenhouse gas acquisition apparatus according to claim 1, wherein the spreading structure comprises a double-sided rack, toggle blocks, and guide rings fixedly connected to an inner wall of the acquisition tube, wherein the double-sided rack is slidably connected in the guide ring, and an end head of the double-sided rack is provided with a pull handle; one end of the toggle block is provided with a gear meshing with the double-sided rack, and the other end of the toggle block is rotatably connected to the pushing plate.

3. The underground greenhouse gas acquisition apparatus according to claim 1 or 2, wherein the acquisition syringe comprises a tapered section and a cylindrical section, the cylindrical section is circumferentially provided with the second vent holes, and an outer cylinder wall of the cylindrical section is closely attached to a hole wall of the extending hole.

4. The underground greenhouse gas acquisition apparatus according to claim 3, wherein the pushing plate is a curved panel, and a surface of the curved panel is closely attached to an inner wall of the acquisition tube.

5. The underground greenhouse gas acquisition apparatus according to claim 1 or 2, wherein an outer wall of the acquisition tube in which the first vent holes are located is covered with a screen.

6. The underground greenhouse gas acquisition apparatus according to claim 5, wherein the screen is sleeved with a fastening strap.

7. The underground greenhouse gas acquisition apparatus according to claim 5, wherein a waterproof gas-permeable membrane is attached to an inner wall of the acquisition tube in which the first vent holes are located.

8. The underground greenhouse gas acquisition apparatus according to claim 7, wherein a waterproof gas-permeable membrane is attached to an inner wall of the acquisition syringe in which the second vent holes are located.

9. The underground greenhouse gas acquisition apparatus according to claim 1, wherein the gas pipe is a rubber hose.

10. The underground greenhouse gas acquisition apparatus according to claim 9, wherein support rings are spaced apart in the gas pipe.