Automatic dust removal and deslagging system for rotary seal of drilling orifice of underground coal mine pressurized air

Abstract

The application discloses a kind of coal mine underground pressure wind drilling hole mouth rotary seal blowout preventer dust removal automatic deslagging system, including hole mouth pipe, hole mouth cross, first sealing assembly, second sealing assembly, filter type negative pressure bag, automatic deslagging device;Drilling construction, first sealing assembly and second sealing assembly alternate effect, realize the sealing under the working condition of axial movement and radial rotation of drill rod, reciprocating alternate sealing until drilling to design hole depth;At the same time, filter type negative pressure bag realizes the filter type dust removal and pre-extraction gas of drilling dust and gas, and automatic deslagging device can fully closed automatic transfer of drilling residue is carried out.The application can realize the whole process of drilling rotary seal, prevent a large amount of dust from pouring out and polluting the working environment during drilling process and gas outburst causes over-limit accident, simultaneously realize the effective separation of solid particles in dust during drilling process, prevent solid particles from entering main negative pressure pipeline and blocking pipeline, realize fully closed automatic transfer of drilling residue, improve the level of automation, reduce labor intensity of operating personnel.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mine drilling, and relates to a method for preventing blowouts and removing dust at the entrance of compressed air drilling in coal mines and for transferring drill cuttings. Specifically, it relates to an automatic slag removal system and method for rotating sealing blowout prevention and dust removal at the entrance of compressed air drilling in coal mines. Background Technology

[0002] In coal mines, compressed air drilling is used for drilling holes for gas control, water exploration, and geological structure exploration. Compressed air drilling causes minimal disturbance to the borehole wall, which is beneficial for drilling in complex geological conditions and results in a high borehole success rate. Furthermore, in recent years, compressed air drilling has been combined with directional drilling to develop pneumatic directional drilling. In gas control drilling in soft, fractured coal seams, this technology not only improves borehole depth and success rate but also offers the advantages of controllable borehole trajectory, high borehole coverage accuracy, and effective avoidance of blind spots in gas control. It has become one of the main technologies for gas control in soft, fractured coal seam mines. However, both compressed air drilling and pneumatic directional drilling present two major challenges: severe dust pollution and the risk of gas exceedance accidents. To address these challenges, numerous researchers have conducted studies. For the severe dust pollution problem, a jet-type dust removal device has been developed. This device uses a high-pressure jet to create a high negative pressure, drawing dust returning from the borehole into the dust removal unit, where it is then suppressed by water mist. Dust collectors were used in conjunction with windbreak curtains for dust removal. Dust returning from the orifice was first removed by a jet dust collector, and any remaining dust was then separated by the windbreak curtain before being removed again by the dust collector. A dust pump truck was developed, integrating the jet dust collector onto a tracked vehicle for easy relocation. However, none of the aforementioned dust collectors achieved a completely sealed dust removal process; a significant amount of dust still returned from the gaps between the dust collector and the drill pipe annulus, polluting the on-site working environment and failing to achieve 100% dust removal. In areas with high gas content... Regarding limitations, various types of blowout preventers (BOPs) have been developed. In recent years, automatic BOPs have been developed. When a large amount of gas is detected surging from the borehole, the automatic controller quickly shuts down the BOP, sealing the gas inside the borehole. However, this automatic BOP is a normally open type, meaning it remains open during drilling. When gas is detected surging from the borehole opening, the time available for the BOP to close is very limited, leading to the possibility of delayed closure and gas leakage. Therefore, the risk of exceeding gas limits still exists. Medium-pressure air drilling in soft, fractured coal seams often generates a large amount of drill cuttings. Currently, manual cleaning is the primary method, resulting in high labor intensity for workers and the fact that cleaning drill cuttings typically takes up drilling time, impacting drilling efficiency. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide an automatic slag removal system for rotary sealing blowout prevention and dust removal at the borehole of compressed air drilling in coal mines. This system solves problems such as incomplete dust control during compressed air drilling, the risk of excessive gas levels, high labor intensity in slag cleaning, and the inefficiency of drilling efficiency improvement.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] An automatic slag removal system for rotary sealing blowout prevention and dust removal at the borehole of a coal mine compressed air drilling hole includes a borehole pipe, a borehole four-way valve, a first sealing component, a second sealing component, a filter-type negative pressure bag, and an automatic slag removal device.

[0006] The orifice pipe, orifice four-way connector, first sealing component, and second sealing component are sequentially arranged from the orifice to the rear and fitted over the drill rod. The front end of the orifice four-way connector is connected to the orifice pipe, the rear end is connected to the first sealing component, the upper end is connected to a filter-type negative pressure bag, and the lower end is connected to an automatic slag discharge device. Both the first and second sealing components can automatically and dynamically seal the outer annulus of the drill rod according to the drilling process to prevent gas and coal dust from overflowing. The second sealing component can move forward with the drill rod and move backward to reset after drilling is completed. The filter-type negative pressure bag can filter solid particles in the dust generated during drilling and introduce the filtered dust and gas into the main negative pressure pipeline through a circular steel pipe to achieve filtration and dust removal and pre-extraction of drilling dust and gas. The automatic slag discharge device can automatically transfer the drill slag falling from the orifice four-way connector in a fully enclosed manner.

[0007] The present invention also includes the following technical features:

[0008] Specifically, the first sealing component and the second sealing component are connected by a plug-in connection, and the second sealing component can be axially moved and reset by a return spring;

[0009] The first sealing assembly includes a first cylindrical outer shell and a first sealing inner cylinder therein, as well as a first bearing between the two. A first expandable bladder is provided on the inner wall of the first sealing inner cylinder, and a first sealing velvet is provided on the outer side of the first expandable bladder.

[0010] The second sealing assembly includes a second cylindrical outer shell and a second sealing inner cylinder therein, as well as a second bearing between the two. A second expandable bladder is provided on the inner wall of the second sealing inner cylinder, and a second sealing velvet is provided on the outer side of the second expandable bladder.

[0011] Specifically, the front end of the first cylindrical outer shell is connected to the rear port of the orifice four-way through a flange, the side wall is provided with a first air inlet, and the rear side wall is provided with an annular groove with a rear opening; the first cylindrical outer shell and the first sealed inner cylinder are unidirectionally moved by the first bearing and sealed by the first sealing ring; the side wall of the first sealed inner cylinder is provided with a first inner air inlet, which can connect to the inside of the first expandable bag and the first air inlet;

[0012] The front end of the second cylindrical outer shell can be inserted into the annular groove, and an axial return spring is provided between the front end and the bottom of the annular groove. The side wall is provided with a second air inlet. The second cylindrical outer shell can move axially along the annular groove. The second cylindrical outer shell and the second sealed inner cylinder achieve single movement through the second bearing and achieve sealing through the second sealing ring. The side wall of the second sealed inner cylinder is provided with a second inner air inlet, which can connect to the inside of the second expandable bag and the second air inlet.

[0013] Specifically, the first and second expandable bags are made of deformable material, which can expand rapidly under high pressure gas, with a pressure resistance of not less than 1 MPa, and also has wear resistance; the first and second sealing fleece are made of soft fleece material and have wear resistance.

[0014] Specifically, the first sealing component and the second sealing component are connected by a telescopic hydraulic cylinder, and the second sealing component can be axially moved and reset by the telescopic hydraulic cylinder.

[0015] The first sealing assembly includes a first cylindrical rigid body and a first annular rubber block, a first extrusion ring, and a first cylindrical piston inside it. A first flange end cap is provided at the front end of the first cylindrical rigid body and the first annular rubber block, and a first flange is provided at the rear end of the first cylindrical rigid body and the first piston.

[0016] The second sealing assembly includes a second cylindrical rigid body and a second annular rubber block, a second extrusion ring, and a second cylindrical piston inside it. A second flange end cap is provided at the front end of the second cylindrical rigid body. A thrust bearing is provided between the second flange end cap and the second annular rubber block. A thrust ball bearing is provided between the second extrusion ring and the second cylindrical piston. A second flange is provided at the rear of the second cylindrical rigid body and the second piston.

[0017] Specifically, the first flange end cap is connected to the rear port of the orifice four-way, the rear side wall of the first cylindrical rigid body is provided with a first oil inlet and outlet, the first annular rubber block, the first extrusion ring and the first cylindrical piston are arranged closely from front to back, the rear outer convex ring and the rear inner ring of the first cylindrical piston can form a first annular oil cavity with the first cylindrical rigid body and the first flange, and the first annular oil cavity is connected to the first oil inlet and outlet. Hydraulic oil enters the first annular oil cavity and pushes the first extrusion ring to squeeze the first annular rubber block so that it contracts radially and deforms, and then seals with the drill pipe.

[0018] Specifically, the second cylindrical rigid body has a second oil inlet / outlet on its rear side wall. The second annular rubber block, the second extrusion ring, and the second cylindrical piston are arranged closely from front to back. The rear outer convex ring and the rear inner ring of the second cylindrical piston can form a second annular oil cavity with the second cylindrical rigid body and the second flange. The second annular oil cavity is connected to the second oil inlet / outlet. Hydraulic oil enters the second annular oil cavity and pushes the second extrusion ring to compress the second annular rubber block, causing it to shrink and deform radially, and then seal it with the drill pipe. The outer wall of the second annular rubber block, the outer wall of the second extrusion ring, the inner wall of the second flange end cover, and the inner wall of the thrust bearing are provided with inner bushings. The inner bushings, the second annular rubber block, and the second extrusion ring can rotate synchronously with the drill pipe.

[0019] Specifically, the telescopic cylinder includes an inner flange rigid body and an outer flange rigid body sleeved thereon, and a piston inserted from the rear into the annular space between the two; the front flange of the inner flange rigid body is fixedly connected to the front end of the outer flange rigid body to form a front-end sealed annular space; the piston includes the piston head end, piston rod body and piston flange connected in sequence from front to back.

[0020] The front flange of the inner flange body is connected to the first flange, and the piston flange is connected to the second flange end cap. Oil inlet and outlet ports are provided at the front and rear positions of the side wall of the outer flange body. The oil inlet and outlet ports are connected to the annular space between the inner flange body and the outer flange body and are respectively located at the front and rear of the piston head. A seal is provided between the piston rod and the inner flange body and between the piston rod and the outer flange body. The seal is located behind the oil inlet and outlet ports.

[0021] Specifically, the filter-type negative pressure bag has two layers, an inner layer that is breathable and does not allow solid particles to pass through, and an outer layer that is not breathable; the upper port of the four-way valve is connected to the space between the inner and outer layers; the circular steel pipe extends from the inner layer and connects to the main negative pressure pipeline; the circular steel pipe has sieve holes on the side wall of the inner layer section.

[0022] Specifically, the automatic slag removal device includes a slag removal hose, a slag collection port, a flexible spiral slag remover, a pneumatic motor, and a slag collection device; the slag collection port is connected to the slag removal hose, and the upper end of the slag collection port is connected to a four-way connector via a plug-in connection; the flexible spiral slag remover is located inside the slag removal hose; the pneumatic motor can drive the flexible spiral slag remover to rotate; and the slag collection device is located at the end of the slag removal hose.

[0023] Compared with the prior art, the present invention has the following technical effects:

[0024] This invention employs a fully enclosed automatic blowout prevention and dust removal system. On one hand, the system utilizes negative pressure to filter dust and gas before extracting them into the main negative pressure pipeline, preventing solid particles from entering and causing blockages. On the other hand, alternating expansion and sealing of the sealing components ensures sealing during axial movement and radial rotation in actual drilling operations, suitable for sealing various drill bit structures. This truly achieves fully enclosed blowout prevention and dust removal throughout the drilling process, eliminating gas exceedances. Furthermore, the system enables fully enclosed automatic transfer of drill cuttings during drilling. In summary, the system method of this invention solves the technical problems of severe dust pollution, easy gas ejection leading to exceedances, and high labor intensity in cleaning large amounts of drill cuttings during compressed air drilling. It ensures safe compressed air drilling, improves the working environment, increases automation levels, reduces the labor intensity of operators, and improves drilling efficiency. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention.

[0026] Figure 2 This is a schematic diagram of the structure of the first sealing component in Embodiment 1 of the present invention.

[0027] Figure 3 This is a schematic diagram of the structure of the second sealing component in Embodiment 1 of the present invention.

[0028] Figure 4 This is a schematic diagram of the filter-type negative pressure bag and circular steel pipe structure of the present invention, as well as a coal dust and gas filtration route diagram.

[0029] Figure 5 This is a schematic diagram of the structure of the automatic slag discharge device of the present invention.

[0030] Figure 6 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention.

[0031] Figure 7 This is a schematic diagram of the structure of the first sealing component in Embodiment 2 of the present invention.

[0032] Figure 8 This is a schematic diagram of the telescopic hydraulic cylinder structure in Embodiment 2 of the present invention.

[0033] Figure 9 This is a schematic diagram of the structure of the second sealing component in Embodiment 2 of the present invention.

[0034] The meanings of the labels in the diagram are as follows:

[0035] 1. Orifice pipe, 2. Orifice four-way valve, 3. First sealing assembly, 4. Second sealing assembly, 5. Filter-type negative pressure bag, 6. Automatic slag discharge device; 7. Telescopic cylinder, 8. Main negative pressure pipeline; 311. First cylindrical outer shell, 312. First sealing inner cylinder, 313. First bearing, 314. First expandable bag, 315. First sealing cloth, 316. First air inlet, 317. Annular groove, 318. First inner air inlet, 319. First sealing ring, 3110. Return spring; 321. First cylindrical rigid body, 322. First annular rubber block, 323. First compression ring, 324. First cylindrical piston, 325. First flange end cap, 326. First flange, 327. First oil inlet / outlet, 328. First seal; 411. Second cylindrical outer shell, 412. Second sealing inner cylinder, 413. Second bearing, 414. 415. Second inflatable bladder; 416. Second sealing cloth; 417. Second air inlet; 418. Second inner air inlet; 419. Second sealing ring; 421. Second cylindrical rigid body; 422. Second annular rubber block; 423. Second compression ring; 424. Second cylindrical piston; 425. Second flange end cap; 426. Thrust bearing; 427. Thrust ball bearing; 428. Second flange; 429. Second oil inlet / outlet. 4210. Inner liner; 4211. Second seal; 501. Inner layer; 502. Outer layer; 503. Circular steel pipe; 601. Slag discharge hose; 602. Slag collection port; 603. Flexible spiral slag discharger; 604. Pneumatic motor; 605. Slag collection device; 701. Inner flange rigid body; 702. Outer flange rigid body; 703. Piston; 704. Oil inlet / outlet; 705. Seal; 706. Piston seal. Detailed Implementation

[0036] This invention discloses an automatic slag removal system and method for rotary sealing blowout prevention and dust suppression at the borehole opening of a coal mine compressed air drilling rig, comprising a borehole pipe, a borehole four-way valve, a first sealing component, a second sealing component, a filter-type negative pressure bag, and an automatic slag removal device. The automatic slag removal device includes a flexible spiral slag remover, a slag removal hose, a slag collection port, a pneumatic motor, and a slag collection device. During drilling, the second sealing component tightly adheres to the drill rod to achieve a seal and moves forward with the drill rod as it rotates. The drilling rig drives the drill rod to rotate and drill forward. When the drilling stroke ends, the first sealing component tightly adheres to the drill rod and seals. Then, the second sealing component is separated from the drill rod and moves backward to its original position. The second sealing component then tightly adheres to the drill rod again to seal, and the first sealing component is then separated from the drill rod. The drilling rig drives the drill rod to rotate and drill forward, repeating this process until the borehole reaches the designed depth. During drilling, a large amount of dust returned from the borehole reaches the four-way cavity at the borehole opening. Under the suction of negative pressure, the solid particles in the dust are filtered out through a filter-type negative pressure bag. The filtered dust and gas enter the main negative pressure pipeline. Drill cuttings generated during drilling are transported to the drill cuttings collection device via the four-way slag discharge port at the borehole opening and an automatic slag discharge device. This system can achieve full rotary sealing during drilling, is suitable for drilling tools of various structures, prevents gas outbursts that could cause accidents, and effectively separates solid particles from the dust during drilling, preventing them from entering the main negative pressure pipeline and clogging it. In addition, it achieves fully enclosed automatic transfer of drill cuttings, improving the level of automation and reducing the labor intensity of operators.

[0037] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0038] Example 1:

[0039] like Figures 1 to 5 As shown, this embodiment provides an automatic slag removal system for rotary sealing blowout prevention and dust removal at the borehole of a coal mine compressed air drilling hole. The system is characterized by including a borehole pipe 1, a borehole four-way connector 2, a first sealing component 3, a second sealing component 4, a filter-type negative pressure bag 5, and an automatic slag removal device 6.

[0040] The orifice pipe 1, orifice cross 2, first sealing assembly 3, and second sealing assembly 4 are sequentially arranged from the orifice to the outside of the drill pipe and fitted over it. The front end of the orifice cross 2 is connected to the orifice pipe 1 via a flange, the rear end to the first sealing assembly 3, the upper end to a filter-type negative pressure bag 5, and the lower end to an automatic slag removal device 6. Both the first sealing assembly 3 and the second sealing assembly 4 can alternately and automatically seal the outer annulus of the drill pipe according to the drilling progress to prevent gas and coal dust from escaping during drilling. The second sealing assembly 4 can move forward with the drill pipe during drilling and... After drilling is completed, it moves backward to reset; the filter-type negative pressure bag 5 can filter solid particles in the dust generated during drilling and introduce the filtered dust and gas into the main negative pressure pipeline 8 through the circular steel pipe 503 to achieve filtering and dust removal of drilling dust and gas and pre-extraction of gas, thereby preventing gas from surging out and causing gas over-limit accidents. At the same time, it can effectively prevent a large number of solid particles from being sucked into the main negative pressure pipeline 8, causing blockage of the negative pressure system; the automatic slag discharge device 6 can automatically transfer the drilling slag that falls from the orifice four-way 2 in a fully enclosed manner, improving the level of automation and reducing the labor intensity of operators.

[0041] The first sealing component 3 and the second sealing component 4 are connected by a plug-in connection, and the second sealing component 4 can be axially moved and reset by the return spring 3110.

[0042] The first sealing assembly 3 includes a first cylindrical outer shell 311 and a first sealing inner cylinder 312 therein, and a first bearing 313 between the two. A first expandable bladder 314 is provided on the inner wall of the first sealing inner cylinder 312, and a first sealing velvet 315 is provided on the outer side of the first expandable bladder 314.

[0043] The second sealing assembly 4 includes a second cylindrical outer shell 411 and a second sealing inner cylinder 412 therein, and a second bearing 413 between the two. A second expandable bladder 414 is provided on the inner wall of the second sealing inner cylinder 412, and a second sealing velvet 415 is provided on the outer side of the second expandable bladder 414.

[0044] The front end of the first cylindrical outer shell 311 is connected to the rear port of the orifice four-way 2 via a flange. The side wall is provided with a first air inlet 316, and the rear side wall is provided with an annular groove 317 with a rear opening. The first cylindrical outer shell 311 and the first sealed inner cylinder 312 are unidirectionally moved by the first bearing 313 and sealed by the first sealing ring 319. The side wall of the first sealed inner cylinder 312 is provided with a first inner air inlet 318, which can connect to the inside of the first expandable bag 314 and the first air inlet 316. More specifically, the first sealing ring 319 is provided on both the front and rear sides of the first bearing 313, and the first air inlet 316 and the first inner air inlet 318 are both located between the two first sealing rings 319.

[0045] The front end of the second cylindrical outer shell 411 can be inserted into the annular groove 317, and an axial return spring 3110 is provided between its front end and the bottom of the annular groove 317. The side wall is provided with a second air inlet 416. The second cylindrical outer shell 411 can move axially along the annular groove 317, and the moving distance is the length of a single drilling stroke. The second cylindrical outer shell 411 and the second sealed inner cylinder 412 achieve single movement through the second bearing 413 and achieve sealing through the second sealing ring 418. The side wall of the second sealed inner cylinder 412 is provided with a second inner air inlet 417, which can connect to the second expandable bladder 414 and the second air inlet 416. More specifically, the second sealing ring 418 is provided on both the front and rear sides of the second bearing 413, and the second air inlet 416 and the second inner air inlet 417 are both located between the two second sealing rings 418.

[0046] During drilling, compressed air is alternately supplied to the first sealing component 3 and the second sealing component 4, causing the expandable bag to expand and bulge. The sealing cloth fits tightly against the drill rod to achieve a seal, preventing gas and coal dust from overflowing from the gap during drilling and solving the problem of excessive gas during drilling.

[0047] The first expandable bladder 314 and the second expandable bladder 414 are made of deformable material, which can expand rapidly under the action of high pressure gas, with a pressure bearing capacity of not less than 1 MPa, and at the same time have good wear resistance; the first sealing fleece 315 and the second sealing fleece 415 are made of soft fleece material, which has good wear resistance.

[0048] The filter-type negative pressure bag 5 has two layers, an inner layer 501 that is breathable but does not allow solid particles to pass through, and an outer layer 502 that is not breathable. The upper port of the four-way valve 2 is connected to the space between the inner layer 501 and the outer layer 502. A circular steel pipe 503 extends from the inner layer 501 and connects to the main negative pressure pipeline 8. The side wall of the circular steel pipe 503 located in the inner layer 501 section has mesh. A large amount of dust and gas generated during drilling is drawn into the filter-type negative pressure bag 5 through the four-way valve 2 under negative pressure. Under the filtering effect of the inner layer 501, the solid particles in the dust are filtered out, while the filtered dust and gas pass through the inner layer 501 into the circular steel pipe 503, and finally into the main negative pressure pipeline 8. This achieves filtration and dust removal of drilling dust and gas, as well as pre-extraction of gas, thereby preventing gas outbursts and gas exceeding limits. At the same time, it can effectively prevent a large amount of solid particles from being sucked into the main negative pressure pipeline 8, causing blockage of the negative pressure system.

[0049] The automatic cuttings removal device 6 includes a cuttings removal hose 601, a cuttings collection port 602, a flexible spiral cuttings remover 603, a pneumatic motor 604, and a cuttings collection device 605. The cuttings collection port 602 is connected to the cuttings removal hose 601, and its upper end is connected to a four-way connector 2. The flexible spiral cuttings remover 603 is located inside the cuttings removal hose 601, and the pneumatic motor 604 drives the flexible spiral cuttings remover 603 to rotate. The cuttings collection device 605 is located at the end of the cuttings removal hose 601. During drilling, high-pressure gas drives the pneumatic motor 604, which in turn drives the flexible spiral cuttings remover 603 to rotate. The cuttings that fall from the four-way connector 2 into the cuttings collection port 602 are then transferred through the cuttings removal hose 601 to the cuttings collection device 605, achieving fully enclosed automatic transfer of the cuttings, improving the level of automation, and reducing the labor intensity of operators. The slag discharge hose 601 is made of flexible material, and the spiral slag discharger has a flexible structure, which can be used for the transfer of drilling slag on various routes.

[0050] This embodiment describes the use of a rotary sealing blowout prevention, dust suppression, and automatic slag removal system at the borehole inlet of an underground compressed air drill in a coal mine for drilling operations. The specific steps include:

[0051] Step 1: Connect the orifice pipe, orifice four-way valve, first sealing assembly, second sealing assembly, filter negative pressure bag, and automatic slag discharge device in sequence;

[0052] Step 2: Connect the first sealing assembly, the second sealing assembly, and the pneumatic motor to the air supply pipeline respectively; connect the filter-type negative pressure bag and the upper end of the circular steel pipe to the main negative pressure pipeline;

[0053] Step 3: Open the air supply valve of the air supply pipeline to supply air to the pneumatic motor. The flexible spiral slag remover starts to rotate. The drill cuttings generated during the drilling process are transferred to the drill cuttings collection device through the rotating flexible spiral slag remover and the slag removal hose.

[0054] Step 4: Open the air supply valve of the air supply pipeline to supply air to the second sealing component. Wait for the second expandable bladder to expand and bulge, and the second sealing cloth to fit tightly against the drill rod.

[0055] Step 5: Start drilling. When the drilling rig feed device finishes one stroke of drilling, open the air supply valve of the air supply line to supply air to the first sealing component. When the first expandable bladder expands and the first sealing cloth is tightly attached to the drill rod, open the air supply line depressurization valve to depressurize the second sealing component. The second expandable bladder contracts and the second sealing cloth separates from the drill rod. Under the action of the return spring, the second sealing component returns to its initial position.

[0056] Step 6: Open the air supply valve of the air supply line to supply air to the second sealing component. When the second expandable bladder expands and the second sealing cloth is tightly attached to the drill rod, open the pressure relief valve of the air supply line to depressurize the first sealing component, the first expandable bladder contracts, the first sealing cloth separates from the drill rod, and the next stroke of drilling begins.

[0057] Step 7: Repeat steps 5 and 6 to complete the drilling.

[0058] Example 2:

[0059] like Figures 6 to 9 As shown, this embodiment provides an automatic slag removal system for rotary sealing blowout prevention and dust removal at the borehole of a coal mine compressed air drilling, including a borehole pipe 1, a borehole four-way valve 2, a first sealing component 3, a second sealing component 4, a filter-type negative pressure bag 5, and an automatic slag removal device 6; the first sealing component 3, the second sealing component 4, and the connection method in this embodiment are different from those in embodiment 1, while the structures of other components are the same.

[0060] In this embodiment, the first sealing component 3 and the second sealing component 4 are connected by a telescopic cylinder 7, and the second sealing component 4 can be axially moved and reset by the telescopic cylinder 7.

[0061] The first sealing assembly 3 includes a first cylindrical rigid body 321 and a first annular rubber block 322, a first compression ring 323 and a first cylindrical piston 324 inside it. A first flange end cap 325 is provided at the front end of the first cylindrical rigid body 321 and the first annular rubber block 322, and a first flange 326 is provided at the rear of the first cylindrical rigid body 321 and the first piston 303.

[0062] The second sealing assembly 4 includes a second cylindrical rigid body 421 and a second annular rubber block 422, a second compression ring 423 and a second cylindrical piston 424 inside it. A second flange end cap 425 is provided at the front end of the second cylindrical rigid body 421. A thrust bearing 426 is provided between the second flange end cap 425 and the second annular rubber block 422. A thrust ball bearing 427 is provided between the second compression ring 423 and the second cylindrical piston 424. A second flange 428 is provided at the rear of the second cylindrical rigid body 421 and the second piston 703.

[0063] The first flange end cap 325 is connected to the rear port of the orifice four-way 2. The front and rear ends of the first cylindrical rigid body 321 are fixedly connected to the first flange end cap 325 and the first flange 326, respectively. The rear side wall of the first cylindrical rigid body 321 is provided with a first oil inlet / outlet 327. The first annular rubber block 322, the first compression ring 323, and the first cylindrical piston 324 are arranged closely from front to back. The rear outer convex ring and the rear inner ring of the first cylindrical piston 324 can form a first annular oil cavity with the first cylindrical rigid body 321 and the first flange 326. The annular oil chamber is connected to the first inlet / outlet 327. Hydraulic oil enters the first annular oil chamber and pushes the first extrusion ring 323 to extrude the first annular rubber block 322, causing it to expand and deform radially and seal with the drill pipe. First seals 328 are provided between the first flange end cap 325 and the first cylindrical rigid body 321, between the first cylindrical piston 324 and the first cylindrical rigid body 321, between the rear outer protruding ring of the first cylindrical piston 324 and the first cylindrical rigid body 321, and between the rear inner ring of the first cylindrical piston 324 and the inner wall of the first flange 326.

[0064] The front and rear ends of the second cylindrical rigid body 421 are fixedly connected to the second flange end cap 425 and the second flange 428, respectively. The rear side wall of the second cylindrical rigid body 421 is provided with a second oil inlet / outlet 429. The second annular rubber block 422, the second extrusion ring 423 and the second cylindrical piston 424 are arranged closely from front to back. The rear outer convex ring and the rear inner ring of the second cylindrical piston 424 can form a second annular oil cavity with the second cylindrical rigid body 421 and the second flange 428, and the second annular oil cavity communicates with the second oil inlet / outlet 429. Hydraulic oil enters the second annular oil cavity and pushes the second extrusion ring 423 to extrude the second annular rubber block 422, causing it to expand and deform radially and seal with the drill pipe. The outer wall of the second annular rubber block 422, the outer wall of the second extrusion ring 423, the inner wall of the second flange end cap 425 and the inner wall of the thrust bearing 426 are provided with inner bushings 4210. The inner bushings 4210, the second annular rubber block 422 and the second extrusion ring 423 can rotate synchronously with the drill pipe. A second seal 4211 is provided between the second flange end cover 425 and the inner bushing 4210, between the rear outer protruding ring of the second cylindrical piston 424 and the second cylindrical rigid body 421, and between the rear inner ring of the second cylindrical piston 424 and the inner wall of the second flange 428.

[0065] The telescopic cylinder 7 includes a cylindrical inner flange rigid body 701 and a cylindrical outer flange rigid body 702 sleeved on it, and a cylindrical piston 703 inserted from the rear into the annulus between the two; the front flange of the inner flange rigid body 701 is fixedly connected to the front end of the outer flange rigid body 702 to form a front sealing annulus; the piston 703 includes the head end of the piston 703, the rod body of the piston 703 and the flange of the piston 703 connected sequentially from front to back.

[0066] The front flange of the inner flange rigid body 701 is connected to the first flange 326, and the flange of the piston 703 is connected to the second flange end cap 425. Oil inlet and outlet ports 704 are provided at the front and rear positions of the side wall of the outer flange rigid body 702. The oil inlet and outlet ports 704 connect the annular space between the inner flange rigid body 701 and the outer flange rigid body 702 and are located at the front and rear of the head end of the piston 703, respectively. A seal 705 is provided between the piston rod and the inner flange rigid body 701 and between the piston rod and the outer flange rigid body 702. This seal 705 is located behind the rear oil inlet and outlet ports 704 and behind the head end of the piston 703. A piston seal 706 is provided between the head of the piston 703 and the inner flange rigid body 701 and between the outer flange rigid body 702.

[0067] This embodiment describes the use of a rotary sealing blowout prevention, dust suppression, and automatic slag removal system at the borehole inlet of an underground compressed air drill in a coal mine for drilling operations. The specific steps include:

[0068] Step 1: Connect the orifice pipe, orifice four-way valve, first sealing assembly, telescopic cylinder, second sealing assembly, filter negative pressure bag, and automatic slag discharge device in sequence;

[0069] Step 2: Connect the first sealing assembly, the second sealing assembly, the telescopic cylinder to the oil supply line, and the pneumatic motor to the air supply line; connect the filter-type negative pressure bag and the upper end of the circular steel pipe to the main negative pressure line.

[0070] Step 3: Open the air supply valve of the air supply pipeline to supply air to the pneumatic motor. The flexible spiral slag remover starts to rotate. The drill cuttings generated during the drilling process are transferred to the drill cuttings collection device through the rotating flexible spiral slag remover and the slag removal hose.

[0071] Step 4: Open the oil supply valve in the oil supply line to supply oil to the second sealing component, and wait for the second annular rubber block to deform and fit tightly against the drill pipe;

[0072] Step 5: Start drilling. When the drilling rig feed device finishes one stroke of drilling, open the oil supply valve of the oil supply line to supply oil to the first sealing component. After the first annular rubber block deforms and fits tightly with the drill rod, open the pressure relief valve of the oil supply line to depressurize the second sealing component. The second annular rubber block resets and separates from the drill rod. Under the action of the telescopic cylinder, the second sealing component returns to its initial position.

[0073] Step 6: Open the oil supply valve of the oil supply line to supply oil to the second sealing component. After the second annular rubber block deforms and fits tightly with the drill pipe, open the pressure relief valve of the oil supply line to depressurize the first sealing component, and the first annular rubber block separates from the drill pipe, and the next stroke of drilling begins.

[0074] Step 7: Repeat steps 5 and 6 to complete the drilling.

[0075] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0076] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0077] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A rotary sealing blowout prevention and dust removal automatic slag discharge system for underground compressed air drilling inlets in coal mines, characterized in that, Includes orifice pipe (1), orifice four-way (2), first sealing assembly (3), second sealing assembly (4), filter negative pressure bag (5), and automatic slag discharge device (6); The orifice pipe (1), orifice cross (2), first sealing component (3), and second sealing component (4) are arranged sequentially from the orifice to the back and are fitted over the drill rod. The front end of the orifice cross (2) is connected to the orifice pipe (1), the rear end is connected to the first sealing component (3), the upper end is connected to the filter-type negative pressure bag (5), and the lower end is connected to the automatic slag discharge device (6). The first sealing component (3) and the second sealing component (4) can automatically and dynamically seal the outer annulus of the drill rod according to the drilling process to prevent gas and coal dust from overflowing. The second sealing component (4) can move forward with the drill rod and move backward to reset after drilling is completed. The filter-type negative pressure bag (5) can filter the solid particles in the dust generated during drilling and introduce the filtered dust and gas into the main negative pressure pipeline (8) through the circular steel pipe (503) to achieve filtering dust removal and pre-extraction of drilling dust and gas. The automatic slag discharge device (6) can automatically transfer the drill slag falling from the orifice cross (2) in a fully enclosed manner. The first sealing component (3) and the second sealing component (4) are connected by a plug-in connection, and the second sealing component (4) can be axially moved and reset by a reset spring (3110); The first sealing assembly (3) includes a first cylindrical outer shell (311) and a first sealing inner cylinder (312) therein, and a first bearing (313) between the two. A first expandable bladder (314) is provided on the inner wall of the first sealing inner cylinder (312), and a first sealing velvet (315) is provided on the outer side of the first expandable bladder (314). The second sealing assembly (4) includes a second cylindrical outer shell (411) and a second sealing inner cylinder (412) therein, and a second bearing (413) between the two. A second expandable bladder (414) is provided on the inner wall of the second sealing inner cylinder (412), and a second sealing velvet (415) is provided on the outer side of the second expandable bladder (414). The front end of the first cylindrical outer shell (311) is connected to the rear port of the orifice four-way (2) through a flange. The side wall is provided with a first air inlet (316), and the rear side wall is provided with an annular groove (317) with a rear opening. The first cylindrical outer shell (311) and the first sealed inner cylinder (312) are connected by a first bearing (313) to achieve single movement and are sealed by a first sealing ring (319). The side wall of the first sealed inner cylinder (312) is provided with a first inner air inlet (318), which can connect to the inside of the first expandable bag (314) and the first air inlet (316). The front end of the second cylindrical outer shell (411) can be inserted into the annular groove (317) and an axial return spring (3110) is provided between its front end and the bottom of the annular groove (317). The side wall is provided with a second air inlet (416). The second cylindrical outer shell (411) can move axially along the annular groove (317). The second cylindrical outer shell (411) and the second sealed inner cylinder (412) achieve single movement through the second bearing (413) and achieve sealing through the second sealing ring (418). The side wall of the second sealed inner cylinder (412) is provided with a second inner air inlet (417) and can connect to the second inflatable bladder (414) and the second air inlet (416).

2. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the inlet of an underground compressed air drilling rig in a coal mine as described in claim 1, characterized in that, The first expandable bladder (314) and the second expandable bladder (414) are made of deformable material, which can expand rapidly under the action of high pressure gas, and have a pressure bearing capacity of not less than 1 MPa, while also having wear resistance; the first sealing velvet cloth (315) and the second sealing velvet cloth (415) are made of soft velvet material, which has wear resistance.

3. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the intake of underground compressed air drilling in coal mines as described in claim 1, characterized in that, The first sealing component (3) and the second sealing component (4) are connected by a telescopic cylinder (7), and the second sealing component (4) can be axially moved and reset by the telescopic cylinder (7); The first sealing assembly (3) includes a first cylindrical rigid body (321) and a first annular rubber block (322), a first compression ring (323) and a first cylindrical piston (324) inside it. A first flange end cap (325) is provided at the front end of the first cylindrical rigid body (321) and the first annular rubber block (322), and a first flange (326) is provided at the rear of the first cylindrical rigid body (321) and the first cylindrical piston (324). The second sealing assembly (4) includes a second cylindrical rigid body (421) and a second annular rubber block (422), a second compression ring (423), and a second cylindrical piston (424) inside it. A second flange end cap (425) is provided at the front end of the second cylindrical rigid body (421). A thrust bearing (426) is provided between the second flange end cap (425) and the second annular rubber block (422). A thrust ball bearing (427) is provided between the second compression ring (423) and the second cylindrical piston (424). A second flange (428) is provided at the rear of the second cylindrical rigid body (421) and the second cylindrical piston (424).

4. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the intake of underground compressed air drilling in coal mines as described in claim 3, characterized in that, The first flange end cap (325) is connected to the rear port of the orifice four-way (2). The rear side wall of the first cylindrical rigid body (321) is provided with a first oil inlet / outlet port (327). The first annular rubber block (322), the first extrusion ring (323) and the first cylindrical piston (324) are arranged closely from front to back. The rear outer protrusion ring and the rear inner ring of the first cylindrical piston (324) can form a first annular oil cavity with the first cylindrical rigid body (321) and the first flange (326). The first annular oil cavity is connected to the first oil inlet / outlet port (327). Hydraulic oil enters the first annular oil cavity and pushes the first extrusion ring (323) to extrude the first annular rubber block (322) to make it radially expand and deform, and then seal it with the drill pipe.

5. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the intake of underground compressed air drilling in coal mines as described in claim 3, characterized in that, The second cylindrical rigid body (421) has a second oil inlet / outlet (429) on its rear side wall. The second annular rubber block (422), the second extrusion ring (423), and the second cylindrical piston (424) are arranged closely from front to back. The rear outer convex ring and the rear inner ring of the second cylindrical piston (424) can form a second annular oil cavity with the second cylindrical rigid body (421) and the second flange (428), and the second annular oil cavity is connected to the second oil inlet / outlet (429). Oil enters the second annular oil chamber and pushes the second extrusion ring (423) to extrude the second annular rubber block (422) to expand and deform radially, and then seals with the drill pipe; the outer wall of the second annular rubber block (422), the outer wall of the second extrusion ring (423), the inner wall of the second flange end cap (425), and the inner wall of the thrust bearing (426) are provided with inner bushings (4210); the inner bushings (4210), the second annular rubber block (422), and the second extrusion ring (423) can rotate synchronously with the drill pipe.

6. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the intake of underground compressed air drilling in coal mines as described in claim 3, characterized in that, The telescopic cylinder (7) includes an inner flange rigid body (701) and an outer flange rigid body (702) sleeved thereon, and a piston (703) inserted from the rear into the annular space between the two; the front flange of the inner flange rigid body (701) is fixedly connected to the front end of the outer flange rigid body (702) to form a front end sealed annular space; the piston (703) includes the head end of the piston (703), the rod body of the piston (703) and the flange of the piston (703) connected in sequence from front to back; The front flange of the inner flange body (701) is connected to the first flange (326), and the piston (703) flange is connected to the second flange end cap (425). An oil inlet and outlet port (704) is provided at the front and rear positions of the side wall of the outer flange body (702). The oil inlet and outlet port (704) connects the annulus between the inner flange body (701) and the outer flange body (702) and is located at the front and rear of the head end of the piston (703). A seal (705) is provided between the piston rod and the inner flange body (701) and between the piston rod and the outer flange body (702). The seal (705) is located behind the oil inlet and outlet port (704).

7. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the intake of underground compressed air drilling in coal mines as described in claim 1, characterized in that, The filter-type negative pressure bag (5) has two layers, an inner layer (501) that is breathable and does not allow solid particles to pass through, and an outer layer (502) that is not breathable. The upper port of the orifice four-way (2) is connected to the space between the inner layer (501) and the outer layer (502). The circular steel pipe (503) extends from the inner layer (501) and connects to the main negative pressure pipeline (8). The circular steel pipe (503) has sieve holes on the side wall of the inner layer (501) section.

8. The automatic slag removal system for rotary sealing blowout prevention and dust suppression at the intake of underground compressed air drilling in coal mines as described in claim 1, characterized in that, The automatic slag discharge device (6) includes a slag discharge hose (601), a slag collection port (602), a flexible spiral slag discharger (603), a pneumatic motor (604), and a slag collection device (605). The slag collection port (602) is connected to the slag discharge hose (601), and the upper end of the slag collection port (602) is connected to a four-way connector (2) through a plug-in connection. The flexible spiral slag discharger (603) is located inside the slag discharge hose (601). The pneumatic motor (604) can drive the flexible spiral slag discharger (603) to rotate. The slag collection device (605) is located at the end of the slag discharge hose (601).

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