Rapid coal seam drilling device

Abstract

The invention relates to the technical field of coal seam protection, and discloses a coal seam rapid drilling device which comprises a gas guide carrier, a first bearing is fixedly connected into the gas guide carrier, a guide-in hole and a plurality of extension mechanisms are formed in the gas guide carrier, and the adjacent extension mechanisms are connected in an axial screwing mode. The extending mechanism comprises an extending carrier fixedly connected with an inner ring of the first bearing, the cooling mechanism comprises a guide pipe fixedly connected to the interior of the guide-in hole, and the drilling mechanism is arranged at the end of the extending carrier in the drilling advancing direction. Through the arrangement of the extension mechanism, the cooling mechanism and the drilling mechanism, during drilling, a gradient cooling field is formed, force generated along with rotation of a drill bit is gradually attenuated and cooled outwards from the axis of the drill bit, liquid nitrogen is introduced into a drilling system based on the low-temperature freezing and phase change expansion characteristics of the liquid nitrogen to achieve dual efficiency, a coal body structure is actively weakened, and the coal body structure is effectively improved. And liquid nitrogen permeation induces microfracture extension, meanwhile, thermal abrasion is restrained, and rapid drilling of the auxiliary coal seam is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of coal seam protection, in particular to a coal seam rapid drilling device. Background Art

[0002] Coal is my country's primary energy source, with annual production remaining high. As shallow coal resources become increasingly depleted, the focus of coal resource development in my country is gradually shifting to deeper areas. However, the significant increase in gas pressure and content in deep coal seams poses a severe challenge to safe coal mining. Pre-drilling coal seam gas extraction is one of the effective methods to mitigate gas hazards.

[0003] However, the high in-situ stress in deep coal seams increases the mechanical strength of the coal mass, restricting drilling efficiency; while the hardness of the coal seams significantly reduces drilling and hole-forming speeds. These factors have led to an increasing problem of fragmentation drilling in high-in-situ stress and hard coal seams. Traditional drilling methods rely on high torque, high speed, and high pressure parameters to increase drilling speed. However, under these conditions, drill bits suffer from severe wear, significantly shortening their service life and producing poor hole formation results. Summary of the Invention

[0004] The purpose of the present invention is to provide a coal seam rapid drilling device to solve the problems of low drilling efficiency and poor hole formation in hard coal seams proposed in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a coal seam rapid drilling device, comprising an air-guiding carrier, a bearing 1 being fixedly connected to the inside of the air-guiding carrier, an inlet hole being opened inside the air-guiding carrier, a plurality of extension mechanisms, adjacent extension mechanisms being connected by axial screwing, the extension mechanism comprising an extension carrier fixedly connected to the inner ring of the bearing 1, a cooling mechanism comprising a guide tube fixedly connected to the inside of the inlet hole, a drilling mechanism arranged at the end of the extension carrier in the drilling forward direction, and a plurality of closing mechanisms respectively arranged at the screwing connection between each two adjacent extension carriers.

[0006] Preferably, a first thread groove is provided at one end of the extension carrier, a second thread groove is provided at the other end of the extension carrier, and a plurality of conveying holes are equidistantly provided inside the extension carrier with the extension carrier as the axis.

[0007] Preferably, when every two adjacent extended carriers are in working state, the conveying holes opened therein are aligned one by one with each other and are interconnected.

[0008] Preferably, the end of the guide tube is fixedly connected to a storage tank, liquid nitrogen is stored in the storage tank, a liquid nitrogen control valve is fixedly connected to the storage tank, and a liquid nitrogen supply valve is fixedly connected to the storage tank.

[0009] Preferably, the drilling mechanism comprises a drill bit threadedly connected to the end of the elongated carrier in the drilling direction, the drill bit surface is equidistantly provided with a plurality of groups of outward holes, and the drill bit interior is equidistantly provided with a plurality of channel holes.

[0010] Preferably, in the working state of the drill bit, the channel holes are in fluid communication with the delivery holes on the elongated carrier, and the channel holes and the outward holes are in internal communication with each other.

[0011] Preferably, the sealing mechanism comprises a bearing two fixedly connected between every two elongated carriers, the bearing two outer ring is fixedly connected with a ring-shaped carrier, the ring-shaped carrier interior is provided with an arc-shaped hole, the arc-shaped hole interior is provided with a ring-shaped air bag, and the ring-shaped carrier surface is fixedly connected with a gas supply pipe close to the ring-shaped air bag side.

[0012] Preferably, the gas supply pipe interior is in communication with the interior of each ring-shaped air bag, and the gas supply pipe interior close to the ring-shaped air bag side is provided with an electrically controlled regulating valve.

[0013] Preferably, in the working state of each ring-shaped air bag, it is controlled to be inflated by the gas supply pipe, deformed in the arc-shaped hole, and tightly fitted with the arc-shaped hole interior.

[0014] Compared with the prior art, the beneficial effects of the present application are: (1) Through the arrangement of the elongated mechanism, the cooling mechanism and the drilling mechanism, a gradient cooling field is formed during drilling, the force generated by the rotation of the drill bit gradually decays and cools from the drill bit shaft center outward, based on the low-temperature freezing and phase change expansion characteristics of liquid nitrogen, liquid nitrogen is introduced into the drilling system to realize double efficiency, the coal body structure is actively weakened, liquid nitrogen penetration induces micro-crack expansion, and thermal wear is inhibited, thereby realizing rapid drilling of the auxiliary coal seam; (2) Through the cooperation of the delivery hole, the outward hole and the channel hole, the liquid nitrogen is regularly guided and sent out, accurately delivered, and the core area is cooled, so as to avoid the diffusion loss of liquid nitrogen in the non-target area and reduce unnecessary waste; (3) Through the cooperation of the elongated carrier carrying the sealing mechanism during drilling, a segmented pressure-tight space is constructed throughout the drilling process, liquid nitrogen flow and cold loss are avoided, when the drill rod advances to the designed stroke, the ring-shaped air bag releases all the sealed intervals, high pressure is generated, dust in the borehole is sent out, the hole wall dust is stripped, the dust removal process does not need to stop drilling, the dust is automatically returned, and the utilization rate of working hours is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a structural diagram of the elongated mechanism, the gas guide carrier and the drilling mechanism of the present application; Figure 2 It is a structural diagram of the drilling mechanism of the present application. Figure 3 It is the schematic diagram of the gas guide carrier split structure of the present application; Figure 4 It is the schematic diagram of the internal section structure of the extension mechanism of the present application; Figure 5 It is the schematic diagram of one section structure of the extension mechanism of the present application; Figure 6 It is the schematic diagram of the section structure of the closing mechanism of the present application; Figure 7 It is the schematic diagram of the overall structure of the device of the present application.

[0016] In the figure: 100, gas guide carrier; 101, bearing one; 102, import hole; 200, extension mechanism; 201, extension carrier; 202, thread groove one; 203, thread groove two; 204, delivery hole; 300, cooling mechanism; 301, guide pipe; 302, storage tank; 400, drilling mechanism; 401, drill bit; 402, release hole; 403, passage hole; 500, closing mechanism; 501, ring-shaped carrier; 502, ring-shaped air bag; 503, bearing two; 504, air supply pipe. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0018] Please refer to Figures 1-7 The present application provides a technical solution: a coal seam rapid drilling device, comprising a gas guide carrier 100, the gas guide carrier 100 is internally fixedly connected with a bearing one 101, the gas guide carrier 100 is internally provided with an import hole 102, a plurality of extension mechanisms 200, adjacent extension mechanisms 200 are connected through axial screwing, the extension mechanism 200 comprises one extension carrier 201 fixedly connected with the inner ring of the bearing one 101, a cooling mechanism 300, comprising a guide pipe 301 fixedly connected inside the import hole 102, a drilling mechanism 400, arranged at the end of the extension carrier 201 in the drilling direction, a plurality of closing mechanisms 500, respectively arranged at the screwing connection between each two adjacent extension carriers 201.

[0019] In use, the air guide carrier 100 is hollow inside and not connected to the hollow cavity inside the extension carrier 201, only connected to 102 and the delivery hole 204, the air guide carrier 100 has the same axis as the extension carrier 201 and is connected, which is convenient for delivering water, compressed air, drilling fluid and other media to the drilling mechanism 400, and injecting high-pressure fluid / gas from the inside of the extension carrier 201 into the borehole to carry the cuttings out of the annulus between the outer wall of the drilling mechanism 400 and the hole wall.

[0020] The extension carrier 201 is provided with a threaded groove one 202 at one end, and a threaded groove two 203 at the other end, and a plurality of delivery holes 204 are equidistantly arranged inside the extension carrier 201 with the extension carrier 201 as the axis.

[0021] In use, referring to Figure 4 , remove the threaded groove two 203 of the extension carrier 201 in the necessary drilling direction and threadedly connect it with the drilling mechanism 400, and the rest of the extension carrier 201 is connected through the threaded groove one 202 and the threaded groove two 203, which is used to extend the drilling depth, and attention should be paid to that the threaded groove one 202 and the threaded groove two 203 cannot affect the working state of the drilling mechanism 400 when they are connected, and it is ensured that the delivery holes 204 on each extension carrier 201 are connected to each other inside after installation, and can deliver liquid nitrogen.

[0022] In the working state of each two adjacent extension carriers 201, the delivery holes 204 arranged are aligned with each other and connected to each other.

[0023] The end of the guide pipe 301 is fixedly connected with a storage tank 302, the storage tank 302 stores liquid nitrogen inside, the storage tank 302 is fixedly connected with a liquid nitrogen control valve inside, and the storage tank 302 is fixedly connected with a liquid nitrogen supply valve inside.

[0024] In use, referring to Figure 7 , the liquid nitrogen control valve and the liquid nitrogen supply valve in the storage tank 302 are used to control the delivery of liquid nitrogen inside the drilling mechanism 400 and the extension carrier 201, to prevent the reverse flow of liquid nitrogen caused by excessive pressure.

[0025] The drilling mechanism 400 comprises a drill bit 401 threadedly connected to the end of the extension carrier 201 in the drilling direction, a plurality of groups of outward holes 402 are equidistantly arranged on the surface of the drill bit 401, and a plurality of passage holes 403 are equidistantly arranged inside the drill bit 401.

[0026] In use, the drill bit 401 advances towards the drilling area. Liquid nitrogen is transported from the passage hole 403 through the outer hole 402, and then continuously pumped from the outer hole 402 to the working area. Since the drill bit 401 is in high-speed operation, the outer hole 403 first directly and efficiently cools the inside of it. As the drill bit 401 rotates, the liquid nitrogen is further thrown out and covers the drilling working surface. This design forms a gradient cooling field centered on the drill bit 401. The closer the area to the drill bit, the higher the cooling intensity. The farther the area, the weaker the cooling effect. The liquid nitrogen also cools the extension carrier 201 through the inside of the delivery hole 204, reducing the waste of liquid nitrogen, and also accurately delivering liquid nitrogen to the working area. The introduction of liquid nitrogen can effectively improve the pore and micro-crack structure of coal, and improve its permeability. Based on its low-temperature freezing and phase change expansion effect, liquid nitrogen is sent into the borehole during drilling. The drill bit 401 continuously drills down, accompanied by the outer hole 402 sending out liquid nitrogen, which deteriorates the strength of the coal body, damages the coal body structure, weakens its mechanical properties, and makes the coal body more easily broken. At the same time, the extremely low temperature and rapid gasification characteristics of liquid nitrogen are used to efficiently absorb drilling heat, significantly reduce the temperature of the drill bit 401, and prolong its service life.

[0027] In the working state of the drill bit 401, the passage hole 403 and the delivery hole 204 on the extension carrier 201 are in fluid communication, and the passage hole 403 and the outer hole 402 are in communication with each other.

[0028] The sealing mechanism 500 includes a bearing 503 fixedly connected between every two extension carriers 201, an annular carrier 501 fixedly connected to the outer ring of the bearing 503, an arc-shaped hole provided in the inside of the annular carrier 501, a ring-shaped air bag 502 provided in the arc-shaped hole, and a gas delivery pipe 504 fixedly connected to the surface of the annular carrier 501 and close to the ring-shaped air bag 502.

[0029] The gas delivery pipe 504 is in communication with the inside of each ring-shaped air bag 502, and an electrically controlled regulating valve is arranged on the side of the gas delivery pipe 504 close to the ring-shaped air bag 502.

[0030] In the working state of each ring-shaped air bag 502, it is controlled to expand by the gas delivery pipe 504, deforms in the arc-shaped hole, and tightly fits in the arc-shaped hole.

[0031] Working principle: In the preparation stage, the positive pressure gas is introduced into the gas delivery pipe 504, and the driving device is connected to the surface of the extended carrier 201, so that the drilling mechanism 400 can perform drilling work. If the length is not enough, multiple extended carriers 201 can be connected by threads to meet the length requirement of drilling. The drill bit 401 of the drilling mechanism 400 starts to work and drills towards the target area. At this time, the cooling mechanism 300 starts to work. The storage tank 302 of the cooling mechanism 300 delivers liquid nitrogen to the inside of the guide pipe 301, and then to the inside of the guide hole 102 through the guide pipe 301. The cavity in the gas delivery carrier 100 delivers the liquid nitrogen to the inside of each delivery hole 204 on the extended carrier 201. The delivery hole 204 guides the liquid nitrogen inside and rotates by itself. While cooling with liquid nitrogen, the liquid nitrogen is sent into the corresponding channel hole 403 through the delivery hole 204, and then discharged from the outer hole 402 through the rotation of the drill bit 401. While cooling the drill bit 401, the inside of the hole wall is continuously cooled. When one of the extended carriers 201 drills into the hole wall, the ring-shaped carrier 501 enters the hole wall at the same time as the extended carrier 201 deepens into the hole. At this time, the electric regulating valve inside the gas delivery pipe 504 in the hole wall first opens, and the gas delivery pipe 504 delivers gas to the inside of the annular air bag 502 on the ring-shaped carrier 501, so that the annular air bag 502 expands. When another extended carrier 201 enters the hole wall, the above operation is repeated to expand another annular air bag 502. A relatively sealed interval is formed inside the hole wall. At the same time, the hollow part of the extended carrier 201 is filled with high-pressure fluid / gas under the existing technology. Each interval will generate a relatively high-pressure interval through the expansion of the annular air bag 502, forming a local high-pressure area. When the annular air bag 502 inside the gas delivery pipe 504 is discharged after reaching a certain degree, the accumulated potential energy generates a transient high-speed jet flow when passing through the arc-shaped hole, and the high-pressure interval is released. The dust inside the hole can be effectively and quickly discharged, overcoming the dust electrostatic adsorption force and surface tension, and making the hardened dust re-fluidized. By periodically inflating and deflating the annular air bag 502, the stripping efficiency is effectively improved compared with continuous airflow, and the probability of sticking is reduced. The above operation is completed.

[0032] The contents not described in detail in the description belong to the prior art known to those skilled in the art. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments or make equivalent replacements of part of the technical features, as long as they are within the spirit and principles of the present application. Any modification, equivalent replacement, improvement, etc. made within the scope of the present application shall be included in the protection scope of the present application.

Claims

1. A coal seam rapid drilling device, characterized in that: include: An air guide carrier (100), wherein a bearing 1 (101) is fixedly connected to the interior of the air guide carrier (100), and an inlet hole (102) is provided inside the air guide carrier (100); A plurality of extension mechanisms (200), adjacent extension mechanisms (200) are connected via axial screwing, and the extension mechanisms (200) include an extension carrier (201) fixedly connected to the inner ring of the bearing (101); A cooling mechanism (300) includes a guide tube (301) fixedly connected to the interior of the introduction hole (102); A drilling mechanism (400) is provided at the end of the extension carrier (201) in the drilling direction; A plurality of closing mechanisms (500) are respectively arranged at the screw connection between every two adjacent extension carriers (201).

2. A coal seam rapid drilling device according to claim 1, characterized in that: A first thread groove (202) is provided at one end of the extension carrier (201), a second thread groove (203) is provided at the other end of the extension carrier (201), and a plurality of conveying holes (204) are equidistantly provided inside the extension carrier (201) with the extension carrier (201) as the axis.

3. A coal seam rapid drilling device according to claim 2, characterized in that: When each two adjacent extended carriers (201) are in a working state, the conveying holes (204) opened therein are aligned one by one with each other and are interconnected.

4. A coal seam rapid drilling device according to claim 3, characterized in that: The end of the guide tube (301) is fixedly connected to a storage tank (302), liquid nitrogen is stored in the storage tank (302), a liquid nitrogen control valve is fixedly connected to the storage tank (302), and a liquid nitrogen supply valve is fixedly connected to the storage tank (302).

5. The coal seam rapid drilling device according to claim 4, characterized in that: The drilling mechanism (400) comprises a drill bit (401) threadedly connected to the end of an extension carrier (201) in the drilling direction, a plurality of groups of external holes (402) are equidistantly formed on the surface of the drill bit (401), and a plurality of channel holes (403) are equidistantly formed inside the drill bit (401).

6. The coal seam rapid drilling device according to claim 5, characterized in that: When the drill bit (401) is in working condition, the channel hole (403) maintains fluid communication with the delivery hole (204) on the extension carrier (201), and the channel hole (403) is internally communicated with the external hole (402).

7. The coal seam rapid drilling device according to claim 6, characterized in that: The sealing mechanism (500) comprises a second bearing (503) fixedly connected between each two extended carriers (201); the outer ring of the second bearing (503) is fixedly connected to the annular carrier (501); an arc-shaped hole is provided inside the annular carrier (501); an annular airbag (502) is provided inside the arc-shaped hole; and an air supply pipe (504) is fixedly connected to the side of the surface of the annular carrier (501) close to the annular airbag (502).

8. The coal seam rapid drilling device according to claim 7, characterized in that: The interior of the air supply pipe (504) is connected to the interior of each of the annular airbags (502), and an electric regulating valve is provided on one side of the air supply pipe (504) close to the annular airbag (502).

9. The coal seam rapid drilling device according to claim 8, characterized in that: When each of the annular airbags (502) is in a working state, it is controlled to expand by the air supply tube (504) and deforms inside the arc-shaped hole until it forms a tight fit with the inside of the arc-shaped hole.

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