A fixed-point sealing device for underground drilling in coal mines

Abstract

This invention relates to the field of mine sealing technology and discloses a fixed-point sealing device for underground coal mine boreholes, comprising: a gas extraction pipe, with two grouting and sealing mechanisms symmetrically arranged at both ends of the mine gas extraction hole sealing section on the outer wall of the gas extraction pipe; the grouting and sealing mechanism includes: a grouting bag, the outer wall of which is divided by an isolation layer into an independent sealing grout injection chamber and an external expansion coating bag, the external expansion coating bag being composed of multiple ring arrays of bag units connected end to end; and a coating supply component, which is connected to the feed end of the external expansion coating bag through a pipeline, the outer wall of each bag unit of the external expansion coating bag being provided with a bursting membrane, the bursting pressure threshold of the bursting membrane being matched with the coating spray coverage requirements; the invention adopts the design of the external expansion coating bag and the bursting membrane, which can realize the instantaneous spraying of liquid sealing coating, uniformly covering the inner wall of the extraction hole, forming an initial adhesive layer, and enhancing the adhesion between the sealing material and the hole wall.

Description

Technical Field

[0001] This invention relates to the field of mine borehole sealing, and more specifically, to a fixed-point sealing device for underground coal mine boreholes. Background Technology

[0002] Underground gas extraction in coal mines is an important measure to ensure safe production. During the gas extraction process, in order to improve extraction efficiency and safety, it is necessary to effectively seal the gas extraction holes to prevent gas leakage and the entry of outside air.

[0003] Existing gas extraction hole sealing technologies typically employ grouting. However, grouting often fails to ensure adequate adhesion between the sealing material and the borehole wall, leading to problems such as incomplete sealing and gas leakage, thus affecting the sealing effect and gas extraction efficiency. Therefore, we propose a fixed-point sealing device for underground coal mine boreholes. Summary of the Invention

[0004] This invention provides a fixed-point sealing device for underground drilling in coal mines, which solves the technical problem that grouting sealing methods in related technologies often fail to ensure sufficient adhesion between the sealing material and the borehole wall, easily leading to incomplete sealing and air leakage.

[0005] This invention provides a fixed-point sealing device for underground coal mine boreholes, comprising: a gas extraction pipe, wherein two grouting and sealing mechanisms are provided on the outer wall of the gas extraction pipe, which are symmetrically arranged at both ends of the sealing section of the mine gas extraction hole;

[0006] The grouting and sealing mechanism includes:

[0007] The grouting bag has an outer wall that is divided into two independent sealing grout injection chambers and an external expansion coating bag by an isolation layer. The external expansion coating bag is composed of multiple ring arrays of bag units that are connected end to end.

[0008] The paint supply component is connected to the feed end of the external expansion paint bladder through a pipeline. The outer wall of each bladder unit of the external expansion paint bladder is equipped with an expansion membrane. The rupture pressure threshold of the expansion membrane is matched with the paint spraying coverage requirements.

[0009] Three water-softening support arms are provided on one side of the grouting bag. When the device reaches the designated sealing position, the support arms use their non-water-hardening properties to automatically center and position the un-grouted grouting bag.

[0010] Liquid sealing coating is injected into the expansion coating bladder through the coating supply component. When the pressure reaches the rupture threshold of the expansion membrane, the coating is sprayed to cover the inner wall of the vent hole to form an initial adhesive layer. Subsequently, expansion slurry is injected into the sealing slurry injection chamber, so that the coating remaining on the outer wall of the grouting bladder and the initial adhesive layer of the hole wall form an integral sealing structure during the solidification process.

[0011] Furthermore, a grouting pipe is fixedly connected to the grouting end of the grouting bag, and a burst valve is connected to the end of the grouting pipe near the grouting bag. The grouting pipe of the first grouting sealing mechanism runs along the gas extraction pipe to the outer end of the air extraction hole and passes through the grouting bag of the second grouting sealing mechanism.

[0012] Furthermore, the grouting pipe is connected to a grouting pump travel frame at its feed end. The grouting pump travel frame includes a glue mixing component and an auxiliary supply pump. The grouting pipe and the grouting pump outlet of the glue mixing component are interconnected. The grouting pump travel frame can travel in the coal mine tunnel.

[0013] Furthermore, two sets of binding ropes are threaded through the inner wall of the grouting bag. The two sets of binding ropes are located at both ends of the grouting bag and are used to tie it tightly from both ends. There are three binding ropes in each set, and none of the binding ropes come into contact with the sealing grout injection chamber of the grouting bag.

[0014] Furthermore, the closed-loop ends of several binding ropes are set at the pull rope buckle. One end of the binding rope is fixedly connected to the pull rope buckle, and the other end of the binding rope extends through the pull rope buckle to the grouting bag. The three binding ropes in each group are tightened sequentially from the inside to the outside.

[0015] Furthermore, an anti-backflow rubber sheet is installed inside the grout outlet of the grouting pipe within the sealing grout injection chamber. The anti-backflow rubber sheet consists of four fan-shaped plates, which form a circle when closed. All four fan-shaped plates of the anti-backflow rubber sheet are rotatably connected to the grout outlet of the grouting pipe, and the rotation angle of the four fan-shaped plates is 0° - 45°.

[0016] Furthermore, the coating supply assembly includes a coating supply pipe, the end of which is fixedly connected to the auxiliary supply pump away from the grouting bladder. The coating supply pipe of the first grouting and sealing mechanism runs along the gas extraction pipe to the outer end of the air extraction hole and passes through the grouting bladder of the second grouting and sealing mechanism.

[0017] Furthermore, a main support frame is provided on the side of the grouting bag near the outer end of the air extraction hole. The main support frame and the gas extraction pipe form a detachable structure, and three assembly slots are provided on the outer peripheral wall of the main support frame.

[0018] Furthermore, the three wall-supporting arms are fixed in the three assembly slots respectively, with each wall-supporting arm corresponding to one of the assembly slots. The wall-supporting arms and the main auxiliary support structure form an inclined structure, and the angle between the wall-supporting arms and the gas extraction pipe is greater than 45°.

[0019] Furthermore, a limit rebound block is provided in the angle between the wall support arm and the assembly groove. The limit rebound block is fixedly connected to the main auxiliary support frame. A pull wire is fixedly provided on one side of the limit rebound block, and the other end of the pull wire is fixedly connected to the top of the wall support arm. The three wall support arms face three directions respectively.

[0020] The beneficial effects of this invention are as follows:

[0021] The present invention adopts the design of an external expansion coating capsule and an expansion membrane, which can realize the instantaneous spraying of liquid sealing coating, uniformly covering the inner wall of the extraction hole and forming an initial adhesive layer. This significantly enhances the adhesion between the sealing material and the hole wall, and effectively solves the problem of weak adhesion in traditional sealing.

[0022] After the initial bonding layer is formed on the borehole wall, the expansion grout is injected to expand the grouting bag. The residual coating on the outer wall of the grouting bag and the initial bonding layer on the borehole wall form an integral sealing structure during the solidification process. This synergistic effect of "coating first and then expanding" makes the sealing material and the borehole wall form a continuous and dense whole, which greatly improves the reliability and durability of the sealing and effectively prevents gas leakage. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the gas extraction pipe structure of the present invention;

[0025] Figure 3 This is the invention Figure 2 Enlarged view of point A in the middle;

[0026] Figure 4 This is a schematic diagram of the external expansion coating capsule liquid injection state structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the external expansion coating capsule of the present invention in the unfilled state;

[0028] Figure 6 This is a schematic diagram of the internal structure of the grouting bag of the present invention;

[0029] Figure 7 This is the invention Figure 6 Enlarged view of point B in the middle;

[0030] Figure 8 This is a schematic diagram of the wall support arm of the present invention in the state of not encountering water;

[0031] Figure 9 This is a schematic diagram of the wall support arm of the present invention in the state of being exposed to water.

[0032] In the diagram: 11. Gas extraction pipe; 12. Grouting pump travel frame; 13. Adhesive mixing component; 14. Auxiliary supply pump; 2. Grouting sealing mechanism; 21. Grouting bladder; 22. Grouting pipe; 23. Bursting valve; 24. Binding rope; 25. Paint supply pipe; 26. External expansion paint bladder; 27. Bursting membrane; 28. Anti-return film; 29. ​​Restraint rope; 201. Pull rope buckle; 31. Main support frame; 32. Binding strap; 33. Wall support arm; 34. Assembly slot; 35. Limiting rebound block; 36. Pull wire. Detailed Implementation

[0033] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0034] like Figure 1 - Figure 9 As shown, a fixed-point sealing device for underground coal mine drilling includes: a gas extraction pipe 11, and two grouting and sealing mechanisms 2 are provided on the outer wall of the gas extraction pipe 11, which are symmetrically arranged at both ends of the gas extraction hole sealing section in the mine.

[0035] Grouting and sealing mechanism 2 includes:

[0036] The grouting bag 21 has an outer wall that is divided into two independent sealing grout injection chambers and an external expansion coating bag 26 by an isolation layer. The external expansion coating bag 26 is composed of multiple ring arrays of bag units that are connected end to end.

[0037] The paint supply component is connected to the feed end of the external expansion paint bladder 26 through a pipeline. The outer wall of the bladder unit of the external expansion paint bladder 26 is provided with an expansion membrane 27. The rupture pressure threshold of the expansion membrane 27 is matched with the paint spraying coverage requirements.

[0038] Three water-softening support arms 33 are provided on one side of the grouting bag 21. When the device reaches the designated sealing position, the support arms 33 use their non-water-hardening properties to automatically center and position the un-grouted grouting bag 21.

[0039] Liquid sealing coating is injected into the outward expansion coating bladder 26 through the coating supply component. When the pressure reaches the rupture threshold of the expansion membrane 27, the coating is sprayed to cover the inner wall of the vent hole to form an initial adhesive layer. Subsequently, expansion slurry is injected into the sealing slurry injection chamber, so that the coating remaining on the outer wall of the grouting bladder 21 and the initial adhesive layer of the hole wall form an integral sealing structure during the solidification process.

[0040] The grouting end of the grouting bag 21 is fixedly connected to the grouting pipe 22. The end of the grouting pipe 22 near the grouting bag 21 is connected to the burst valve 23. The grouting pipe 22 of the first grouting sealing mechanism 2 runs along the gas extraction pipe 11 to the outer end of the air extraction hole and passes through the grouting bag 21 of the second grouting sealing mechanism 2.

[0041] The grouting pipe 22 is connected to the grouting pump travel frame 12 at the feeding end. The grouting pump travel frame 12 includes a glue mixing component 13 and an auxiliary supply pump 14. The grouting pipe 22 and the grouting pump outlet end of the glue mixing component 13 are interconnected. The grouting pump travel frame 12 can travel in the coal mine tunnel.

[0042] Two sets of binding ropes 29 are threaded through the inner wall of the grouting bag 21. The two sets of binding ropes 29 are located at both ends of the grouting bag 21 and are used to tie it tightly from both ends. There are three binding ropes in each set. None of the binding ropes 29 can contact the sealing grout injection chamber of the grouting bag 21.

[0043] Several binding ropes 29 have their closed-loop ends set at the pull rope buckle 201. One end of the binding rope 29 is fixedly connected to the pull rope buckle 201, and the other end of the binding rope 29, the auxiliary binding pull rope 24, passes through the pull rope buckle 201 and extends out of the grouting bag 21. The three binding ropes 29 in each group are tightened sequentially from the inside to the outside.

[0044] Inside the grout outlet of the grouting pipe 22, which is located inside the grout injection chamber, there is a backflow prevention sheet 28. The backflow prevention sheet 28 consists of four fan-shaped plates. When the four fan-shaped plates are closed, they form a circle. All four fan-shaped plates of the backflow prevention sheet 28 are rotatably connected to the grout outlet of the grouting pipe 22. The rotation angle of the four fan-shaped plates is 0-45°.

[0045] The coating supply assembly includes a coating supply pipe 25. The end of the coating supply pipe 25 away from the grouting bag 21 is fixedly connected to the auxiliary supply pump 14. The coating supply pipe 25 of the first grouting sealing mechanism 2 runs along the gas extraction pipe 11 to the outer end of the air extraction hole and passes through the grouting bag 21 of the second grouting sealing mechanism 2.

[0046] A main support frame 31 is provided on the side of the grouting bag 21 near the outer end of the air extraction hole. The main support frame 31 and the gas extraction pipe 11 form a detachable structure. Three assembly slots 34 are provided on the outer peripheral wall of the main support frame 31.

[0047] All pipes running along the gas extraction pipe 11 are secured to the main support frame 31 with straps 32.

[0048] The three wall-supporting arms 33 are fixed in the three assembly slots 34 respectively. The wall-supporting arms 33 and the assembly slots 34 correspond one-to-one. The wall-supporting arms 33 and the main auxiliary support frame 31 form an inclined structure, and the angle between the wall-supporting arms 33 and the gas extraction pipe 11 is greater than 45°.

[0049] A limit rebound block 35 is provided in the angle between the wall support arm 33 and the assembly groove 34. The limit rebound block 35 is fixedly connected to the main auxiliary support frame 31. A pull wire 36 is fixedly provided on one side of the limit rebound block 35, and the other end of the pull wire 36 is fixedly connected to the top of the wall support arm 33. The three wall support arms 33 face three directions respectively.

[0050] The design of the grouting pump travel frame 12 allows the grouting equipment to move through coal mine tunnels, improving the equipment's mobility and on-site adaptability. The design of the restraint rope 29 and the pull rope buckle 201 facilitates the pre-tightening and fixing of the grouting bag 21, simplifying the installation process.

[0051] By setting three water-softening wall-supporting arms 33, the wall-supporting arms 33 maintain their rigidity before grouting, which enables the grouting bag 21 to be automatically centered in the borehole, avoiding contact between the grouting bag 21 and the borehole wall, ensuring the uniformity of subsequent paint spraying and grout injection, and improving the sealing quality.

[0052] In use, first, put the two grouting bags 21 in their initial state onto the gas extraction pipe 11, and adjust the position of the two grouting bags 21 so that they match the section of the extraction hole that needs to be sealed. Then, the operator pulls the binding rope 24 from the inside out in sequence, so that the two sets of binding ropes 29 are pulled from the inside out in sequence, and fixes the binding rope 24 with the rope buckle 201, thereby fixing the grouting bags 21. Then, put the main pipe auxiliary support frame 31 into the preset position on the gas extraction pipe 11, and tighten the screws of the main pipe auxiliary support frame 31 to fix the main pipe auxiliary support frame 31 tightly. Then, use the binding strap 32 to tie the passing pipe to the main pipe auxiliary support frame 31. The same operation is performed for both grouting bags 21.

[0053] Secondly, the operator inserts the assembled gas extraction pipe 11 into the air extraction hole, so that one grouting bag 21 is at the inner end of the blocked section and the other is at the outer end of the blocked section. When the three wall-supporting arms 33 are inserted into the air extraction hole, they always maintain a certain rigidity and a certain opening angle. The three wall-supporting arms 33 can keep the grouting bag 21 in the center of the air extraction hole before grouting, without contacting the inner wall of the air extraction hole, and leaving some space.

[0054] Other workers added the raw materials required for grouting to the adhesive mixing unit 13 in proportion and stirred them. They also connected the grouting pipe 22 to the outlet of the adhesive mixing unit 13 and connected the paint supply pipe 25 to the outlet of the auxiliary pump 14.

[0055] First, liquid coating is pumped into the coating supply pipe 25 via the auxiliary pump 14. The coating then enters the outer expansion coating bladders 26 of the two grouting bags 21 through the coating supply pipe 25. As the amount of liquid coating in the outer expansion coating bladders 26 increases, all the outer expansion coating bladders 26 gradually expand. When the expansion coating bladders 26 expand to the capacity of the rupture membrane 27, the rupture membrane 27 will burst instantly. The liquid coating in the outer expansion coating bladders 26 is instantly sprayed onto the inner wall of the air extraction hole. Each outer expansion coating bladder 26 is individually connected to the coating supply pipe 25. Even if all the outer expansion coating bladders 26 do not burst at the same time, it will not affect the liquid flow. The liquid inlet of the rupture membrane 27 is a rubber structure. Liquid will only enter under a certain pressure impact. After individual rupture membranes 27 burst, it will not affect the liquid flow into other rupture membranes 27.

[0056] When the outer coating bladders 26 on the two grouting bags 21 expand and burst, grout is injected into the two grouting pipes 22 through the adhesive mixing component 13. Grout is then injected into the sealing grout injection chambers in the two grouting bags 21 through the grouting pipes 22, causing the grouting bags 21 to expand until the air pressure in the grouting bags 21 reaches the preset air pressure value. At this time, the grouting bags 21 are fully expanded and bulge, making full contact with the inner wall of the air extraction hole. The liquid coating on the inner wall of the air extraction hole is not completely solidified and forms an integral part with the remaining liquid coating on the grouting bags 21.

[0057] As grout continues to be injected into the first grouting bag 21, the pressure exceeds the withstand capacity of the burst valve 23, causing it to burst and break. At this point, the grout flows out and gradually fills the space between the two grouting bags 21.

[0058] When the burst valve 23 breaks and stops grouting into the grouting bag 21, the backflow prevention film 28 closes under pressure to prevent leakage.

[0059] When grout is injected into the space between the two grouting bags 21, the wall support arm 33 comes into contact with water, and the grout softens. After softening, the elasticity of the pull wire 36 pulls the three wall support arms 33 into the grout.

[0060] The grouting bag 21 has a double-layer structure: the isolation layer realizes the layered function of "first coating coverage and then grout sealing". The outer expansion coating bag 26 sprays coating to form an initial bonding layer, and the sealing grout injection chamber injects expansion grout to form an overall sealing structure. The dual effect improves the sealing performance and integrity of the hole.

[0061] The external expansion coating capsule 26 consists of an annular array capsule unit and an expansion membrane 27. The annular array capsule unit ensures that the coating uniformly covers the hole wall 360°. The rupture pressure threshold of the expansion membrane 27 matches the coating spraying requirements, ensuring that the coating covers the hole wall in a spray pattern, forming a uniform initial adhesive layer and avoiding sealing defects caused by uneven coating distribution.

[0062] Water-softening support arm 33: When not in contact with water, it maintains its hard properties, allowing the un-grouted grouting bag 21 to be automatically centered and positioned, avoiding displacement caused by friction between the bag and the hole wall; after softening in water, it is elastically recovered through the pull wire 36, preventing the hardened support arm 33 from affecting the solidification of the grout, thus achieving both positioning and sealing effects.

[0063] Structure of restraint rope 29 + pull rope buckle 201: Two sets of three restraint ropes 29 are tightened from the inside to the outside and fixed by pull rope buckle 201. The grouting bag 21 is tied from both ends to prevent the bag from shifting due to gravity or vibration before grouting, ensuring the accurate initial position of the bag and improving the sealing accuracy.

[0064] Backflow prevention film 28: After the four fan-shaped plates close, they form a circular sealing surface. During grouting, the grout is allowed to flow into the sealing grout injection chamber in one direction. After the burst valve 23 is broken, it closes automatically to prevent the grout from flowing back into the grouting pipe 22, thus avoiding pipe blockage or grout waste.

[0065] Main support frame 31 + assembly slot 34 + limit rebound block 35: The detachable structure facilitates quick installation to the gas extraction pipe 11. The assembly slot 34 fixes the wall support arm 33 and controls its tilt angle, with the angle between it and the pipe body >45°. The limit rebound block 35 is linked to the wall support arm 33 through the pull wire 36, ensuring that the wall support arm 33 can be smoothly retracted after it softens in water, thus improving the ease of operation of the device.

[0066] Grouting pipe 22 installation design: The grouting pipe 22 and paint supply pipe 25 of the first grouting sealing mechanism 2 run along the gas extraction pipe 11 and pass through the second grouting bag 21, reducing the exposure of the pipeline, avoiding damage to the pipeline by debris in the borehole, and improving the adaptability of the device in narrow spaces.

[0067] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms based on the guidance of the present embodiments, all of which are within the protection scope of the present embodiments.

Claims

1. A fixed-point sealing device for underground drilling in coal mines, characterized in that, The utility model relates to a kind of gas extraction pipe and its sealing device, including: Gas extraction pipe (11), the outer wall of gas extraction pipe (11) is provided with two grouting sealing mechanism (2), respectively symmetrically arranged in the both ends of mine gas extraction hole sealing section; The grouting sealing mechanism (2) includes: Grouting bag (21), its outer wall is separated into mutually independent sealing slurry injection chamber and outer expansion coating bag (26) double-layer structure by isolation layer, the outer expansion coating bag (26) is made of multiple annular array and head-to-tail communication bag body unit; Coating supply assembly is communicated with the feed end of outer expansion coating bag (26) by pipeline, the bag body unit outer wall of outer expansion coating bag (26) is each equipped with expansion membrane (27), and the rupture pressure threshold of expansion membrane (27) is matched with coating jet covering demand; One side of the grouting bag (21) is equipped with three water-softening type wall-supporting arms (33), when the device reaches the specified sealing position, wall-supporting arm (33) is automatically positioned in the middle by the unhardened characteristics of water, and the grouting bag (21) is not grouted; One side of the grouting bag (21) close to the outer end of the air hole is provided with a main pipe auxiliary support frame (31), the main pipe auxiliary support frame (31) and the gas extraction pipe (11) form a detachable structure, and three assembly grooves (34) are formed on the outer circumferential wall of the main pipe auxiliary support frame (31). Three wall-supporting arms (33) are respectively fixed in three assembly grooves (34), the wall-supporting arm (33) and the assembly groove (34) are one-to-one corresponding, the wall-supporting arm (33) and the main pipe auxiliary support frame (31) form an inclined structure, and the included angle between the wall-supporting arm (33) and the gas extraction pipe (11) is greater than 45°. The included angle between the wall-supporting arm (33) and the assembly groove (34) is provided with a limit rebound block (35), the limit rebound block (35) is fixedly connected with the main pipe auxiliary support frame (31), one side of the limit rebound block (35) is fixedly provided with a collection wire (36), and the other end of the collection wire (36) is fixedly connected with the top end of the wall-supporting arm (33), and three wall-supporting arms (33) are respectively directed to three directions. By coating supply assembly, liquid sealing hole coating is injected into outer expansion coating bag (26), when the pressure reaches the rupture threshold of expansion membrane (27), the coating forms an initial adhesive layer in the form of jet covering the inner wall of the air hole, and then expanding slurry is injected into the sealing slurry injection chamber, so that the residual coating on the outer wall of the grouting bag (21) and the initial adhesive layer on the hole wall form an integral sealing structure during the solidification process.

2. The device according to claim 1, characterized in that, The grouting end of the grouting bag (21) is fixedly connected with a grouting pipe (22), one end of the grouting pipe (22) close to the grouting bag (21) is connected with a blasting valve (23), and the grouting pipe (22) of the first grouting sealing mechanism (2) is wired along the gas extraction pipe (11) to the outer end of the air hole, passing through the grouting bag (21) of the second grouting sealing mechanism (2).

3. The device according to claim 2, characterized in that, The feeding end of the grouting pipe (22) is connected with a grouting pump traveling frame (12), the grouting pump traveling frame (12) comprises a glue liquid mixing element (13) and an auxiliary supply pump (14), the grouting pipe (22) and the grouting pump outflow end of the glue liquid mixing element (13) are in communication with each other, and the grouting pump traveling frame (12) travels in a coal mine passage.

4. The point sealing device for underground coal drilling according to claim 1, characterized in that, The inner wall of the grouting bag (21) is provided with two groups of binding ropes (29), and the two groups of binding ropes (29) are located at two ends of the grouting bag (21) respectively, and are used for tightening the grouting bag (21) from two ends thereof, each group of the binding ropes (29) has three, and all the binding ropes (29) cannot contact the plugging slurry injection chamber of the grouting bag (21).

5. The device according to claim 4, characterized in that, The closed loop end of the plurality of binding ropes (29) is provided with a pull rope buckle (201), one end of the binding rope (29) is fixedly connected with the pull rope buckle (201), the other end of the binding rope (29) is extended out of the grouting bag (21) through the pull rope buckle (201), and the three binding ropes (29) in each group are sequentially tightened from inside to outside.

6. The point sealing device for underground coal drilling according to claim 2, characterized in that, The grouting pipe (22) is provided with a return glue blocking piece (28) inside the outflow port inside the plugging slurry injection chamber, the return glue blocking piece (28) is composed of four fan-shaped plates, the four fan-shaped plates are circular after being closed, the four fan-shaped plates of the return glue blocking piece (28) are rotationally connected with the outflow port of the grouting pipe (22), and the rotation angle of the four fan-shaped plates is 0°-45°.

7. The device according to claim 3, characterized in that, The paint supply assembly comprises a paint supply pipe (25), one end of the paint supply pipe (25) away from the grouting bag (21) is fixedly connected with the auxiliary supply pump (14), the paint supply pipe (25) of the first grouting sealing mechanism (2) is wired along the gas extraction pipe (11) to the outer end of the air extraction hole, and passes through the grouting bag (21) of the second grouting sealing mechanism (2).

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