Single-wall air bag open-closed dual-purpose sampling device and method

Abstract

The single-wall air bag open-closed dual-purpose sampling device comprises a sampling pipe and a sampling drill bit arranged at the front end of the sampling pipe, a sealing baffle is arranged on the rear side of the sampling pipe, an air measuring hole which is through front and back is formed in the sealing baffle, an air measuring valve is connected to the rear side of the air measuring hole, and an air bag is arranged on the inner wall of the rear side of the sampling pipe in a hidden mode. A one-way water injection pipeline system for injecting water into the air bag to expand is arranged in the wall of the sampling pipe. In order to solve a series of problems that an existing closed sampling device is generally large in weight, complex in structure, tedious in sampling operation and the like, the structure of the sampling device is simplified, and closed acquisition of an underground coal sample of a coal mine is achieved only by adopting one layer of steel pipe and combining with the water injection expansion air bag; meanwhile, the rock core pipe can also be used as a conventional open type rock core pipe (namely, the water injection expansion air bag is taken out, or water is not injected). In short, the device is simple in structure, stable, reliable and convenient to operate and carry.

Description

Technical Field

[0001] The present invention belongs to the technical field of on-site sampling and testing of coal seam gas content, and particularly relates to a single-wall airbag open-closed dual-purpose sampling device and method. Background Art

[0002] Most coal mining enterprises use the direct method to measure the coal seam gas content, and directly calculate the coal seam gas content by drilling gas-containing samples, on-site desorption, and laboratory testing. The key lies in on-site sampling. For the determination of the gas content of coal seam fixed-point sampling, open-type core tubes are generally used. However, during the process of lifting the drill, the gas escapes too much, resulting in low accuracy of gas content measurement. At present, although some scholars and engineers have invented a series of closed core sampling devices, mainly including structures such as a core outer tube, a core inner tube, and a drive tube, which have at least three layers of structures. On the one hand, the structure is complex, increasing the overall weight of the core sampling device. On the other hand, the sealing effect after core sampling is not good, and the sealing performance is poor. Summary of the Invention

[0003] In order to solve the above technical problems existing in the prior art, the present invention provides a special single-wall airbag open-closed dual-purpose sampling device and method for gas drainage, which has a simple structure, is convenient to operate, is easy to seal, and has a good sealing effect.

[0004] To solve the above technical problems, the present invention adopts the following technical solution: A single-wall airbag open-closed dual-purpose sampling device includes a sampling pipe and a sampling drill bit provided at the front end of the sampling pipe. A sealing baffle is provided at the rear side of the sampling pipe. A gas measurement hole that penetrates through the front and rear is opened on the sealing baffle. A gas measurement valve is connected to the rear side of the gas measurement hole. An airbag is hiddenly provided on the inner wall at the rear side of the sampling pipe. A one-way water injection pipeline system for injecting water into the airbag to expand is provided inside the sampling pipe wall.

[0005] The one-way water injection pipeline system includes an axial hole, a front mounting hole, and a rear mounting hole. The front mounting hole and the rear mounting hole are opened along the radial direction of the sampling pipe. The air inlet nozzle of the airbag extends into and is fixed in the front mounting hole. A first stud plug is provided at the outer port of the front mounting hole. The rear mounting hole corresponds to the sealing baffle. An L-shaped hole is opened inside the sealing baffle. One end port of the L-shaped hole is connected to the inner end of the rear mounting hole. The other end port of the L-shaped hole is located on the rear side surface of the sealing baffle. The axial hole is parallel to the center line of the sampling pipe. The axial hole communicates the front mounting hole and the rear mounting hole. The rear port of the axial hole is located on the rear side surface of the sealing baffle. A second stud plug is provided inside the rear port of the axial hole. A one-way valve for communicating the L-shaped hole and the axial hole is provided in the rear mounting hole.

[0006] The one-way valve includes a third stud plug, a compression spring, and a sealing ball. The diameter of the L-shaped hole is smaller than the diameter of the rear mounting hole. The third stud plug is provided at the outer port of the rear mounting hole. The sealing ball is provided at the inner end of the port mounting hole and blocks the hole opening of the L-shaped hole. The two ends of the compression spring are respectively connected to the inner end of the third stud plug and the sealing ball.

[0007] The outer circumference of the front end of the sampling tube is provided with an external thread connection buckle, and the inner circumference of the rear end of the sampling tube is provided with a first internal thread connection buckle; the rear end of the sampling drill bit is provided with a second internal thread connection buckle that is threadedly connected to the external thread connection buckle. There is a centrally penetrating central hole inside the sampling drill bit, and the diameter of the central hole is equal to the inner diameter of the sampling tube. A plurality of sampling cutting teeth are provided on the front annular surface of the sampling drill bit, and a plurality of drilling cutting teeth are provided on the outer circumference of the sampling drill bit. The maximum rotary diameter of the drilling cutting teeth is greater than the maximum rotary diameter of the sampling cutting teeth.

[0008] An annular groove is provided on the inner circumference of the front side of the sampling tube, and the non-inflated water-filled airbag is hidden on the inner wall of the annular groove.

[0009] The single-wall airbag open-closed dual-purpose sampling method is carried out by using the single-wall airbag open-closed dual-purpose sampling device, including open sampling and closed sampling; during open sampling, the airbag is not inflated with water, the front end of the sampling tube is open, and the front side of the coal sample entering the sampling tube is open; during closed sampling, high-pressure water is injected into the L-shaped hole, and the high-pressure water pushes the sealing ball to further compress the compression spring. The L-shaped hole is communicated with the axial hole through the rear mounting hole, and the high-pressure water is injected forward into the airbag through the axial hole, and the airbag expands to block the front port of the sampling tube, thereby sealing the coal sample entering the sampling tube.

[0010] The open sampling specifically includes the following steps: (1) Connect the front end of the sampling tube to the rear end of the sampling drill bit, close the gas measurement valve, then connect the rear end of the sampling tube to the drill pipe, and then insert the sampling drill bit and the sampling tube into the bottom of the coal seam borehole. (2) Start the drilling rig to drive the drill pipe to rotate and drive the drill pipe forward. The drill pipe drives the sampling tube and the sampling drill bit to rotate. The sampling cutting teeth and the drilling cutting teeth drill forward, and the coal sample enters the sampling tube through the central hole of the sampling drill bit. After the drill pipe is advanced 1-2 meters forward, stop drilling, and the coal sample is stored in the sampling tube. (3) Control the drilling rig to withdraw the drill, and separate the sampling tube from the drill pipe. (4) Connect the rubber hose of the on-site desorption instrument to the gas measurement valve, and slowly open the valve to perform on-site desorption of the gas content of the coal sample. (5) After the on-site desorption is completed, pour out the coal sample in the sampling tube and put it into the coal sample tank, take it out of the well, and conduct laboratory tests.

[0011] The closed sampling specifically includes the following steps: S1: Connect the front end of the sampling tube to the rear end of the sampling drill bit, close the gas measurement valve, then connect the rear end of the sampling tube to the drill pipe, and then insert the sampling drill bit and the sampling tube into the bottom of the coal seam borehole. S2: Start the drill rig to drive the drill pipe to rotate and move forward. The drill pipe drives the sampling pipe and the sampling bit to rotate. The sampling picks and the drilling picks drill forward. The coal sample enters the sampling pipe through the central hole of the sampling bit. After the drill pipe advances 1 - 2 meters, stop drilling and store the coal sample in the sampling pipe. S3: Inject high - pressure water into the drill pipe. The pressure of the high - pressure water is 0.5 - 2 MPa. The high - pressure water advances forward into the rear port of the sampling pipe, enters the L - shaped hole, and the high - pressure water pushes the sealing ball to further compress the compression spring. The sealing ball moves outward along the rear mounting hole until the L - shaped hole communicates with the axial hole through the rear mounting hole. The high - pressure water is injected forward into the airbag through the axial hole. After the airbag expands, it fills the inner circle of the sampling pipe, thus blocking the front port of the sampling pipe. The coal sample is sealed in the sampling pipe between the sealing baffle and the airbag. S4: Cut off the high - pressure water. Under the action of the compression spring, the sealing ball moves inward along the rear mounting hole, and the sealing ball blocks the L - shaped hole. At the same time, control the drill rig to retract the drill, and separate the sampling pipe from the drill pipe. S5: Connect the rubber hose of the on - site desorption instrument to the gas - measuring valve, and slowly open the valve to conduct on - site desorption of the coal sample gas content. S6: After the on - site desorption is completed, screw out the first stud plug from the front mounting hole, drain the water in the expansion airbag, restore the airbag to a flat shape and hide it in the annular groove. S7: Pour out the coal sample in the sampling pipe and load it into the coal sample can, take it out of the underground and conduct laboratory tests.

[0012] Adopting the above - mentioned technical solution, compared with the prior art, the present invention has the following beneficial effects: (1) When the present invention conducts airtight sampling, by injecting high - pressure water, driving the sealing ball of the one - way valve to move to open the water path, injecting the high - pressure water into the airbag, and after the airbag expands, blocking the front port of the sampling pipe, thus realizing airtight sampling. At the same time, cut off the high - pressure water. Under the elastic force of the compression spring, the sealing ball blocks the L - shaped hole, and the water in the airbag does not flow back, maintaining a constant pressure to ensure the sealing performance of the front port.

[0013] (2) When the present invention conducts open sampling, the airbag can be taken out and the inner port of the front mounting hole can be blocked; or the airbag can be not removed and no water injection is required during the sampling process.

[0014] In summary, aiming at a series of problems such as the generally large weight, complex structure, and cumbersome sampling operation of the existing airtight sampling devices, the present invention simplifies the structure of the sampling device, and only uses a single - layer steel pipe combined with an injection - inflated airbag to realize the airtight acquisition of coal samples in coal mines. At the same time, the invention can also be used as a conventional open - type core tube (that is: take out the injection - inflated airbag, or no water injection is required). In short, the present invention has a simple structure, is stable and reliable, and is convenient for operation and carrying. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of the external structure of the present invention; Figure 2 is a schematic diagram of the internal structure of the present invention; Figure 3 is Figure 2 an enlarged view of the sampling tube in Figure 4 is Figure 2 an enlarged view of the sampling drill bit in Figure 5 is a schematic diagram of the internal structure of the sampling tube after the airbag is inflated by water injection. Specific Embodiments

[0016] The following further describes in detail the embodiments of the present invention in conjunction with the drawings and embodiments.

[0017] As Figures 1 - 5 shown, the single-wall airbag open-closed dual-purpose sampling device of the present invention includes a sampling tube 1 and a sampling drill bit 2 provided at the front end of the sampling tube 1. A sealing baffle 3 is provided at the rear side of the sampling tube 1. A front and rear through gas detection hole is opened on the sealing baffle 3. A gas detection valve 4 is connected to the rear side of the gas detection hole. An airbag 5 is hiddenly provided on the inner wall at the rear side of the sampling tube 1. A one-way water injection pipeline system for injecting water into the airbag 5 to expand is provided in the tube wall of the sampling tube 1.

[0018] The one-way water injection pipeline system includes an axial hole 6, a front mounting hole 7 and a rear mounting hole 8. The front mounting hole 7 and the rear mounting hole 8 are opened along the radial direction of the sampling tube 1. The air inlet nozzle of the airbag 5 extends into and is fixed in the front mounting hole 7. A first stud plug 9 is provided at the outer port of the front mounting hole 7. The rear mounting hole 8 corresponds to the sealing baffle 3. An L-shaped hole 10 is opened in the sealing baffle 3. One port of the L-shaped hole 10 is connected to the inner end of the rear mounting hole 8, and the other port of the L-shaped hole 10 is located on the rear side surface of the sealing baffle 3. The axial hole 6 is parallel to the center line of the sampling tube 1. The axial hole 6 communicates with the front mounting hole 7 and the rear mounting hole 8. The rear port of the axial hole 6 is located on the rear side surface of the sealing baffle 3. A second stud plug 11 is provided inside the rear port of the axial hole 6. A one-way valve for communicating the L-shaped hole 10 with the axial hole 6 is provided in the rear mounting hole 8.

[0019] The one-way valve includes a third stud plug 12, a compression spring 13 and a sealing ball 14. The diameter of the L-shaped hole 10 is smaller than the diameter of the rear mounting hole 8. The third stud plug 12 is provided at the outer port of the rear mounting hole 8. The sealing ball 14 is provided at the inner end of the port mounting hole and blocks the orifice of the L-shaped hole 10. The two ends of the compression spring 13 are respectively connected to the inner end of the third stud plug 12 and the sealing ball 14.

[0020] An external thread connection buckle 15 is provided on the outer circle at the front end of the sampling tube 1; a first internal thread connection buckle 16 is provided on the inner circle at the rear end of the sampling tube 1; a second internal thread connection buckle 17 that is threadedly connected to the external thread connection buckle 15 is provided at the rear end of the sampling drill bit 2; Inside the sampling bit 2, there is a central hole 18 that penetrates through from front to back. The diameter of the central hole 18 is equal to the inner diameter of the sampling tube 1. A number of sampling picks 19 are provided on the front annular surface of the sampling bit 2, and a number of drilling picks 20 are provided on the outer circle of the sampling bit 2. The maximum rotary diameter of the drilling picks 20 is greater than the maximum rotary diameter of the sampling picks 19.

[0021] An annular groove 21 is provided on the inner circle of the front side of the sampling tube 1, and the non-water-injected and non-expanded airbag 5 is hidden in the inner wall of the annular groove 21.

[0022] The single-wall airbag open-closed dual-purpose sampling method is carried out by using the single-wall airbag open-closed dual-purpose sampling device, including open sampling and closed sampling; during open sampling, the airbag is not inflated with water, the front end of the sampling tube 1 is open, and the front side of the coal sample entering the sampling tube 1 is open; during closed sampling, high-pressure water is injected into the L-shaped hole 10, the high-pressure water pushes the sealing ball 14 to further compress the compression spring 13. The L-shaped hole 10 is communicated with the axial hole 6 through the rear mounting hole 8, and the high-pressure water is injected forward into the airbag through the axial hole 6. The airbag 5 expands to block the front port of the sampling tube 1, thereby sealing the coal sample entering the sampling tube 1.

[0023] The open sampling specifically includes the following steps: (1) Connect the front end of the sampling tube 1 to the rear end of the sampling bit 2, close the gas measuring valve 4, then connect the rear end of the sampling tube 1 to the drill pipe, and then insert the sampling bit 2 and the sampling tube 1 into the bottom of the coal seam borehole; (2) Start the drill rig to drive the drill pipe to rotate and drive the drill pipe forward. The drill pipe drives the sampling tube 1 and the sampling bit 2 to rotate. The sampling picks 19 and the drilling picks 20 drill forward. The coal sample enters the sampling tube 1 through the central hole 18 of the sampling bit 2. After the drill pipe advances 1 - 2 meters forward, stop drilling, and the coal sample is stored in the sampling tube 1; (3) Control the drill rig to retract the drill, and separate the sampling tube 1 from the drill pipe; (4) Connect the rubber hose of the on-site desorption instrument to the gas measuring valve 4, and slowly open the valve to perform on-site desorption of the gas content of the coal sample; (5) After the on-site desorption is completed, pour out the coal sample in the sampling tube 1 and put it into the coal sample can, take it out of the underground, and conduct laboratory tests.

[0024] The closed sampling specifically includes the following steps: S1: Connect the front end of the sampling tube 1 to the rear end of the sampling bit 2, close the gas measuring valve 4, then connect the rear end of the sampling tube 1 to the drill pipe, and then insert the sampling bit 2 and the sampling tube 1 into the bottom of the coal seam borehole; S2: Start the drill rig to drive the drill pipe to rotate and move forward. The drill pipe drives the sampling pipe 1 and the sampling bit 2 to rotate. The sampling picks 19 and the drilling picks 20 drill forward. The coal sample 22 enters the sampling pipe 1 through the central hole 18 of the sampling bit 2. After the drill pipe advances 1 - 2 meters forward, stop drilling. The coal sample 22 is stored in the sampling pipe 1. S3: Inject high - pressure water into the drill pipe. The pressure of the high - pressure water is 0.5 - 2 MPa. The high - pressure water moves forward into the rear port of the sampling pipe 1, enters the L - shaped hole 10. The high - pressure water pushes the sealing ball 14 to further compress the compression spring 13. The sealing ball 14 moves outward along the rear mounting hole 8 until the L - shaped hole 10 communicates with the axial hole 6 through the rear mounting hole 8. The high - pressure water is injected forward into the airbag through the axial hole 6. After the airbag expands, it fills the inner circle of the sampling pipe 1, thus blocking the front port of the sampling pipe 1. The coal sample 22 is sealed in the sampling pipe 1 between the sealing baffle 3 and the airbag. S4: Disconnect the high - pressure water. Under the action of the compression spring 13, the sealing ball 14 moves inward along the rear mounting hole 8, and the sealing ball 14 blocks the L - shaped hole 10. At the same time, control the drill rig to retract the drill, and separate the sampling pipe 1 from the drill pipe. S5: Connect the rubber hose of the on - site desorber to the gas measuring valve 4, and slowly open the valve to conduct on - site desorption of the gas content of the coal sample. S6: After the on - site desorption is completed, screw out the first stud plug 9 from the front mounting hole 7, drain the water in the inflated airbag, restore the airbag to a flat shape and hide it in the annular groove 21. S7: Pour out the coal sample in the sampling pipe 1 and load it into the coal sample can, take it out of the mine and conduct laboratory tests.

[0025] The above embodiments illustrate the basic principles and characteristics of the present invention. However, the above only illustrates the preferred embodiments of the present invention and is not limited by the described embodiments. Those of ordinary skill in the art, inspired by this patent, without departing from the spirit of the present invention and the scope protected by the claims, can also make many forms of deformation and improvement, which are all within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be subject to the appended claims.

Claims

1. A single-walled airbag open-closed dual-purpose sampling device, comprising a sampling tube and a sampling drill bit arranged at the front end of the sampling tube, characterized in that: A sealing baffle is provided on the rear side of the sampling tube, on which a gas measuring hole which is transparent from front to back is opened, a gas measuring valve is connected to the rear side of the gas measuring hole, an air bag is hidden on the inner wall on the rear side of the sampling tube, and a one-way water injection pipeline system is provided inside the wall of the sampling tube for injecting water into the air bag for expansion.

2. The single-wall airbag open-closed dual-purpose sampling device according to claim 1 is characterized in that: The one-way water injection pipeline system includes an axial hole, a front mounting hole and a rear mounting hole. The front mounting hole and the rear mounting hole are opened along the radial direction of the sampling tube. The air inlet nozzle of the airbag extends into and is fixed in the front mounting hole. A first stud plug is provided at the outer port of the front mounting hole. The rear mounting hole corresponds to the sealing baffle. An L-shaped hole is opened in the sealing baffle. One port of the L-shaped hole is connected to the inner end of the rear mounting hole, and the other port of the L-shaped hole is located on the rear side of the sealing baffle. The axial hole is parallel to the center line of the sampling tube. The axial hole connects the front mounting hole and the rear mounting hole. The rear port of the axial hole is located on the rear side of the sealing baffle. A second stud plug is provided inside the rear port of the axial hole. A one-way valve for connecting the L-shaped hole and the axial hole is provided in the rear mounting hole.

3. The single-wall airbag open-closed dual-purpose sampling device according to claim 2 is characterized in that: The one-way valve includes a third stud plug, a compression spring and a sealing ball. The diameter of the L-shaped hole is smaller than the diameter of the rear mounting hole. The third stud plug is arranged at the outer port of the rear mounting hole. The sealing ball is arranged at the inner end of the rear mounting hole and seals the L-shaped hole. The two ends of the compression spring are respectively connected to the inner end of the third stud plug and the sealing ball.

4. The single-wall airbag open-closed dual-purpose sampling device according to claim 3 is characterized in that: The front end outer circle of the sampling tube is provided with an external thread connection buckle, and the rear end inner circle of the sampling tube is provided with a first internal thread connection buckle; the rear end of the sampling drill bit is provided with a second internal thread connection buckle threadedly connected with the external thread connection buckle; There is a central hole that is transparent from front to back inside the sampling drill bit, and the diameter of the central hole is equal to the inner diameter of the sampling tube. A plurality of sampling picks are arranged on the annular surface at the front end of the sampling drill bit, and a plurality of drilling picks are arranged on the outer circle of the sampling drill bit. The maximum rotation diameter of the drilling picks is greater than the maximum rotation diameter of the sampling picks.

5. The single-wall airbag open-closed dual-purpose sampling device according to claim 4 is characterized in that: An annular groove is arranged on the inner circle of the front side of the sampling tube, and the air bag which is not inflated by water is hidden in the inner wall of the annular groove.

6. A single-walled airbag open-closed dual-purpose sampling method, using the single-walled airbag open-closed dual-purpose sampling device as claimed in claim 5, characterized in that: It includes open sampling and closed sampling. During the open sampling process, the airbag is not filled with water to expand, the front end of the sampling tube is open, and the front side of the coal sample entering the sampling tube is open. During the closed sampling, high-pressure water is injected into the L-shaped hole, and the high-pressure water pushes the sealing ball to further compress the compression spring. The L-shaped hole is connected with the axial hole through the rear mounting hole, and high-pressure water is injected forward into the airbag through the axial hole. The airbag expands and blocks the front port of the sampling tube, thereby sealing the coal sample entering the sampling tube.

7. The single-wall airbag open-closed dual-purpose sampling method according to claim 6 is characterized in that: Open sampling specifically includes the following steps: (1) Connect the front end of the sampling tube to the rear end of the sampling drill bit, close the gas measuring valve, then connect the rear end of the sampling tube to the drill pipe, and then insert the sampling drill bit and the sampling tube into the bottom of the coal seam borehole; (2) Turn on the drilling rig to drive the drill rod to rotate and drive the drill rod forward. The drill rod drives the sampling tube and the sampling drill bit to rotate. The sampling pick and the drilling pick drill forward. The coal sample enters the sampling tube from the center hole of the sampling drill bit. The drill rod stops drilling after it advances 1 to 2 meters forward. The coal sample is stored in the sampling tube. (3) Operate the drilling rig to retract the drill and separate the sampling tube from the drill pipe; (4) Connect the rubber hose of the on-site desorption instrument to the gas measuring valve, and slowly open the valve to perform on-site desorption of the gas content of the coal sample; (5) After the on-site desorption is completed, the coal sample in the sampling tube is poured out and placed into a coal sample tank, which is then taken out of the mine for laboratory testing.

8. The single-wall airbag open-closed dual-purpose sampling method according to claim 6 is characterized in that: Closed sampling The following steps are involved: S1: Connect the front end of the sampling tube to the rear end of the sampling drill bit, close the gas measuring valve, then connect the rear end of the sampling tube to the drill pipe, and then insert the sampling drill bit and the sampling tube into the bottom of the coal seam borehole; S2: Turn on the drilling rig to drive the drill rod to rotate and drive the drill rod forward. The drill rod drives the sampling tube and the sampling drill bit to rotate. The sampling pick and the drilling pick drill forward. The coal sample enters the sampling tube from the center hole of the sampling drill bit. The drill rod stops drilling after it advances 1 to 2 meters forward, and the coal sample is stored in the sampling tube. S3: Inject high-pressure water into the drill pipe with a pressure of 0.5~2 MPa. The high-pressure water enters forward to the rear port of the sampling tube and enters the L-shaped hole. The high-pressure water pushes the sealing ball to further compress the compression spring. The sealing ball moves outward along the rear mounting hole until the L-shaped hole is connected to the axial hole through the rear mounting hole. The high-pressure water is injected forward into the airbag through the axial hole. After the airbag expands, it fills the inner circle of the sampling tube, thereby blocking the front port of the sampling tube. The coal sample is sealed in the sampling tube between the sealing baffle and the airbag. S4: Disconnect the high-pressure water. Under the action of the compression spring, the sealing ball moves inward along the rear mounting hole, and the sealing ball blocks the L-shaped hole. At the same time, the drilling rig is controlled to retract the drill and separate the sampling tube from the drill pipe. S5: Connect the rubber hose of the on-site desorption instrument to the gas measuring valve, and slowly open the valve to perform on-site desorption of the gas content of the coal sample; S6: After the on-site desorption is completed, the first stud plug is screwed out of the front installation hole to release the water in the expanded airbag, and the airbag is restored to a flat shape and hidden in the annular groove; S7: Pour out the coal sample in the sampling tube and put it into the coal sample tank, take it out of the mine and conduct laboratory testing.

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