Gas distribution and slag guide device for reverse circulation down-the-hole hammer drilling

Abstract

The invention discloses an air distribution and slag guide device for reverse circulation down-the-hole hammer drilling. The air distribution and slag guide device comprises an outer pipe, a slag guide pipe, an air distribution power mechanism, a drill bit and a drilling cutting conveying mechanism. The outer pipe is provided with an air inlet. The slag guide pipe is coaxially arranged in the outer pipe, and an annular gas distribution channel is formed between the slag guide pipe and the outer pipe and communicated with the gas inlet. And the bottom of the slag guide pipe is provided with a slag suction port, and a slag guide channel is formed in the slag guide pipe. The air distribution power mechanism comprises an air supply machine and an air distribution piston, and the piston slides in the annular air distribution channel in a reciprocating mode. The drill bit is connected with the outer pipe and used for crushing rock strata, and an inner shell and the flow guide cover form an annular cavity. The flow guide cover is provided with a gas distribution nozzle, and the spraying direction corresponds to the slag suction opening. And the drilling cutting conveying mechanism is arranged in the slag guide channel, axially extends and is used for conveying the drilling cuttings to the earth surface. The invention aims to solve the problem that rock debris is easy to retain in a slag guide channel in the existing reverse circulation drilling technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of down-the-hole hammer devices, and particularly relates to a gas distribution and cuttings guiding device for reverse circulation down-the-hole hammer drilling. BACKGROUND

[0002] With the development of modern drilling engineering technology, especially the increasing number of deep hole and complex formation drilling operations, higher requirements are put forward for rock breaking efficiency and cuttings removal capacity in the drilling process. In the process of reverse circulation down-the-hole hammer drilling, high-efficiency distribution of high-pressure gas and rapid guiding of cuttings at the bottom of the hole need to be realized to ensure continuous and efficient drilling operation.

[0003] The existing gas distribution and cuttings guiding structure of the reverse circulation down-the-hole hammer has significant defects. The gas distribution and cuttings conveying system are independent of each other, and lack of linkage optimization design, which leads to easy retention of cuttings in the cuttings guiding channel, especially in large-diameter cuttings or viscous formations, which is more prone to blockage, seriously affecting the cuttings removal efficiency. Therefore, it is urgent to develop a gas distribution and cuttings guiding device for reverse circulation down-the-hole hammer drilling to solve the technical problem of easy retention of cuttings in the cuttings guiding channel in the existing reverse circulation drilling technology. SUMMARY

[0004] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide a gas distribution and cuttings guiding device for reverse circulation down-the-hole hammer drilling to improve the problem of easy retention of cuttings in the cuttings guiding channel in the existing reverse circulation drilling technology.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] The gas distribution and cuttings guiding device for reverse circulation down-the-hole hammer drilling comprises an outer pipe, a cuttings guiding pipe, a gas distribution power mechanism, a drill bit and a drill cuttings conveying mechanism. The outer pipe is provided with an air inlet. The cuttings guiding pipe is coaxially arranged in the inner part of the outer pipe, and a ring-shaped gas distribution channel is formed between the cuttings guiding pipe and the outer pipe, which is in communication with the air inlet. The side of the cuttings guiding pipe close to the ground is provided with a cuttings outlet, and the bottom of the cuttings guiding pipe is provided with a cuttings suction port. The inner part of the cuttings guiding pipe constitutes a cuttings guiding channel for conveying broken cuttings. The gas distribution power mechanism comprises a gas supply machine and a gas distribution piston connected to the output end of the gas supply machine, and the gas distribution piston reciprocates in the ring-shaped gas distribution channel. The drill bit is connected to the outer pipe and is used to break the rock formation. The drill bit is provided with a shell driven by the drill bit support and a flow guide cover. A ring-shaped chamber is formed between the shell and the flow guide cover. The flow guide cover is provided with at least one gas distribution nozzle, and the jet direction of the gas distribution nozzle corresponds to the cuttings suction port. The drill cuttings conveying mechanism is arranged in the cuttings guiding channel and extends in the axial direction of the cuttings guiding pipe, and is used to convey the drill cuttings to the ground. Wherein, the gas flows through the ring-shaped gas distribution channel, the ring-shaped chamber, the gas distribution nozzle, the cuttings suction port, the cuttings guiding channel, the cuttings outlet and the external environment in sequence.

[0007] Further, the drill bit further comprises a pressure stabilizing and flow equalizing chamber for connecting the ring-shaped gas distribution channel and the ring-shaped chamber.

[0008] Further, the drill bit further comprises at least one rectifying orifice plate; the rectifying orifice plate is arranged between the annular gas distribution channel and the pressure stabilizing and flow equalizing cavity; the cross section of the rectifying orifice plate is in a conical structure; a plurality of uniformly distributed gas through holes are formed on the rectifying orifice plate for guiding and uniformly distributing the gas flow.

[0009] Further, the height of the flow guide cover along the axial direction of the outer pipe is lower than the height of the drill beads arranged on the drill bit.

[0010] Further, the flow guide cover is arranged in extension along the axial and radial directions of the outer pipe.

[0011] Further, the flow guide cover is provided with a flow guide surface which is a circular arc surface.

[0012] Further, the drill cuttings conveying mechanism of the slag guide pipe is a spiral conveying rod or a pneumatic conveying pipe.

[0013] Further, a throttle orifice plate is arranged inside the gas distribution nozzle, and a throttle orifice with a smaller diameter than the gas distribution nozzle is formed on the throttle orifice plate.

[0014] Further, a slag collector is arranged at the slag suction port.

[0015] Further, the slag collector is in a horn mouth shape, and a wear-resistant alloy layer is coated on the inner surface thereof.

[0016] Compared with the prior art, the present application has the following beneficial effects:

[0017] 1. Based on the annular gas distribution channel formed by the outer pipe and the slag guide pipe coaxially arranged inside the outer pipe, and the channel being communicated with the gas inlet, the high-pressure gas is stably conveyed along the annular space to provide a uniform gas distribution basis for the down-the-hole hammer; based on the gas distribution power mechanism comprising a gas supply machine and a gas distribution piston driven by the gas supply machine, and the piston reciprocatingly sliding in the annular gas distribution channel to form a periodic pressure pulse gas flow, the down-the-hole hammer can be efficiently driven to impact and break the rock stratum; based on the annular cavity formed by the drill bit middle shell and the flow guide cover, and the flow guide cover being provided with a gas distribution nozzle corresponding to the slag discharge port in the jet direction, the high-pressure gas is directionally injected into the bottom of the slag guide channel to effectively stir and carry the rock cuttings; based on the drill cuttings conveying mechanism being axially arranged in the slag guide channel, and the gas sequentially flowing through the annular gas distribution channel, the annular cavity, the gas distribution nozzle, the slag suction port, the slag guide channel, the slag discharge port and the external environment, the broken rock cuttings can be continuously conveyed to the ground to avoid the accumulation of rock cuttings at the bottom of the hole. Through the integrated structure design of the gas distribution and slag guide, the present application realizes the synergistic operation of efficient gas utilization and continuous removal of rock cuttings.

[0018] 2. The pressure stabilizing and flow equalizing cavity added based on the drill bit, the annular gas distribution channel and the annular chamber are communicated, the pressure stabilization and preliminary flow equalization of high-pressure gas are realized, and the pressure stability of the gas flow into the drill bit is effectively improved; the rectifier orifice plate is arranged between the annular gas distribution channel and the pressure stabilizing and flow equalizing cavity, the cross section of the rectifier orifice plate is a tapered structure, and a plurality of uniformly distributed gas through holes are formed in the tapered structure, the gas flow is further guided and uniformly distributed, and the gas is ensured to be stably delivered to the gas distribution nozzle. The structure realizes the pressure stabilization and flow rectification, and enhances the impact stability of the down-the-hole hammer and the rock breaking efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 FIG. 1 is a structural schematic diagram of a gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to the present application;

[0020] Figure 2 FIG. 2 is a sectional view of the gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to the present application; Figure 1 FIG. 3 is an enlarged view of A in FIG. 2.

[0021] In the drawings: 100, outer pipe; 200, gas inlet; 300, slag guiding pipe; 301, annular gas distribution channel; 302, slag discharge port; 303, slag guiding channel; 304, slag suction port; 400, gas distribution power mechanism; 401, gas supply machine; 402, gas distribution piston; 500, drill bit; 501, outer shell; 502, flow guide cover; 503, throttle orifice plate; 504, annular chamber; 505, gas distribution nozzle; 506, pressure stabilizing and flow equalizing cavity; 507, rectifier orifice plate; 508, gas through hole; 509, drill bead; 600, drill cuttings conveying mechanism. DETAILED DESCRIPTION

[0022] Hereinafter, the present application will be further described in conjunction with the drawings and specific embodiments. It should be noted that the following described embodiments or technical features can be combined in any manner to form new embodiments without conflict.

[0023] It should be noted that when an element is referred to as being “fixed” to another element, it can be directly on the other element or there can be an intervening element. When an element is referred to as being “connected” to another element, it can be directly connected to the other element or there can be an intervening element. The terms “vertical”, “horizontal”, “left”, “right”, and similar terms used herein are for illustrative purposes only and are not intended to be limiting.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items.

[0025] Referring to Figures 1-2 , the detailed description of a preferred embodiment of the present application:

[0026] The application discloses a gas distribution and drill cuttings discharge device for reverse circulation down-the-hole hammer drilling, which is characterized by comprising an outer pipe 100, a drill cuttings discharge pipe 300, a gas distribution power mechanism 400, a drill bit 500 and a drill cuttings conveying mechanism 600. The outer pipe 100 is provided with an air inlet 200. The drill cuttings discharge pipe 300 is coaxially arranged in the inner part of the outer pipe 100, and a ring-shaped gas distribution channel 301 is formed between the drill cuttings discharge pipe 300 and the outer pipe 100, which is communicated with the air inlet 200. The side of the drill cuttings discharge pipe 300 close to the ground is provided with a drill cuttings discharge port 302, and the bottom of the drill cuttings discharge pipe 300 is provided with a drill cuttings suction port 304. The inner part of the drill cuttings discharge pipe 300 constitutes a drill cuttings discharge channel 303 for conveying broken rock cuttings. The gas distribution power mechanism 400 comprises a gas supply machine 401 and a gas distribution piston 402 connected to the output end of the gas supply machine 401, and the gas distribution piston 402 reciprocates in the ring-shaped gas distribution channel 301. The drill bit 500 is connected to the outer pipe 100 and used for breaking rock layers. The drill bit 500 is provided with an outer shell 501 and a flow guide cover 502 driven by the drill bit 500. A ring-shaped chamber 504 is formed between the outer shell 501 and the flow guide cover 502. The flow guide cover 502 is provided with at least one gas distribution nozzle 505, and the jet direction of the gas distribution nozzle 505 corresponds to the drill cuttings suction port 304. The drill cuttings conveying mechanism 600 is arranged in the drill cuttings discharge channel 303 and extends in the axial direction of the drill cuttings discharge pipe 300, and is used for conveying drill cuttings to the ground. In the device, gas flows through the ring-shaped gas distribution channel 301, the ring-shaped chamber 504, the gas distribution nozzle 505, the drill cuttings suction port 304, the drill cuttings discharge channel 303, the drill cuttings discharge port 302 and the external environment in sequence. The core function of the device is to realize stable gas distribution of high-pressure gas and continuous removal of rock cuttings at the bottom of the hole, thereby improving the reverse circulation down-the-hole hammer drilling efficiency.

[0027] The outer pipe 100 and the coaxially arranged drill cuttings discharge pipe 300 constitute a ring-shaped gas distribution channel 301, which is communicated with the air inlet 200. The gas distribution piston 402 of the gas distribution power mechanism 400 is slidably arranged in the ring-shaped gas distribution channel 301. The end of the drill bit 500 is provided with a ring-shaped chamber 504 formed by the outer shell 501 and the flow guide cover 502, and the flow guide cover 502 is provided with a gas distribution nozzle 505 pointing to the drill cuttings discharge port 302. The drill cuttings conveying mechanism 600 axially penetrates the drill cuttings discharge channel 303. The outer pipe 100 can be selectively connected to the drill bit 500 in two connection modes. In one mode, the outer pipe 100 is connected to the output end of a driving motor to drive the drill bit 500 to rotate in the circumferential direction and realize feeding. In the other mode, the outer pipe 100 is driven by the gas distribution device to drive the drill bit 500 to independently feed in the axial direction.

[0028] The gas supply machine 401 drives the gas distribution piston 402 to reciprocate in the annular gas distribution channel 301, to generate a periodic high-pressure pulse gas flow to drive the rock hammer to impact the rock stratum; at the same time, the high-pressure gas is directed to be sprayed into the bottom of the slag guide channel 303 from the gas distribution nozzle 505 through the annular chamber 504, to stir the rock debris and make it enter the drill cuttings conveying mechanism 600, to realize the continuous conveying of the rock debris.

[0029] The high-pressure gas enters the annular gas distribution channel 301 through the gas inlet 200, and the reciprocating movement of the gas distribution piston 402 forms an alternating pressure change to push the rock hammer to work; after the drill bit 500 breaks the rock stratum, the rock debris is entrained to the slag discharge port 302 under the action of the gas flow of the gas distribution nozzle 505, and the drill cuttings conveying mechanism 600 continuously outputs the rock debris along the slag guide channel 303 to the ground.

[0030] It can be understood that, based on the outer tube 100 and the slag guide tube 300 coaxially arranged inside the outer tube 100 to form the annular gas distribution channel 301, and the channel being communicated with the gas inlet 200, the stable conveying of the high-pressure gas along the annular space is realized, to provide a uniform gas distribution basis for the rock hammer; based on the gas distribution power mechanism 400 including the gas supply machine 401 and the gas distribution piston 402 driven by the gas supply machine 401, and the piston reciprocating sliding in the annular gas distribution channel 301, a periodic pressure pulse gas flow is formed, which can efficiently drive the rock hammer to impact and break the rock stratum; based on the annular chamber 504 formed by the outer shell 501 and the flow guide cover 502 in the drill bit 500, and the gas distribution nozzle 505 arranged on the flow guide cover 502 and corresponding to the slag discharge port 302 in the spraying direction, the high-pressure gas is directed to be sprayed into the bottom of the slag guide channel 303, to effectively stir and carry the rock debris; based on the drill cuttings conveying mechanism 600 axially arranged in the slag guide channel 303, the broken rock debris can be continuously conveyed to the ground, to avoid the accumulation of rock debris at the bottom of the hole. The present application realizes the synergistic operation of efficient gas utilization and continuous removal of rock debris through the integrated structure design of gas distribution and slag guide.

[0031] Preferably, the drill bit 500 further includes a pressure stabilizing and flow equalizing chamber 506 for communicating the annular gas distribution channel 301 with the annular chamber 504. The core function of this structure is to stabilize and preliminarily distribute the high-pressure gas through the pressure stabilizing and flow equalizing chamber 506, to improve the stability of the gas flow, to provide a basis for efficient gas distribution in the drill bit 500.

[0032] The pressure stabilizing and flow equalizing chamber 506 is arranged inside the drill bit 500, the inlet end thereof is communicated with the annular gas distribution channel 301, and the outlet end thereof is communicated with the annular chamber 504 formed by the outer shell 501 and the flow guide cover 502 of the drill bit 500, to constitute a transitional pressure stabilizing space.

[0033] In operation, the pulsed high-pressure gas from the annular gas distribution channel 301 first enters the pressure stabilizing and flow equalizing cavity 506, the internal space of which plays a buffering and equalizing role for the gas flow, effectively suppressing pressure fluctuations, so that the gas enters the annular chamber 504 at a more stable pressure and flow rate. The high-pressure gas is transported to the pressure stabilizing and flow equalizing cavity 506 through the annular gas distribution channel 301, where pressure regulation and preliminary flow equalization are completed, and then stably introduced into the annular chamber 504, and finally forms a stable directional jet through the gas distribution nozzle 505 on the flow guide cover 502, effectively stirring the hole bottom cuttings.

[0034] Preferably, the drill bit 500 further comprises at least one flow regulating orifice plate 507; the flow regulating orifice plate 507 is arranged between the annular gas distribution channel 301 and the pressure stabilizing and flow equalizing cavity 506; the cross section of the flow regulating orifice plate 507 is a tapered structure; and a plurality of uniformly distributed gas through holes 508 are formed on the flow regulating orifice plate 507 for guiding and uniformly distributing the gas flow. The core function of this structure is to guide and uniformly distribute the high-pressure gas through the tapered flow regulating orifice plate 507, further stabilize the gas flow, and ensure its smooth delivery to the gas distribution nozzle 505, thereby improving the working stability and rock breaking efficiency of the down-the-hole hammer.

[0035] At least one flow regulating orifice plate 507 with a tapered cross section is arranged between the annular gas distribution channel 301 and the pressure stabilizing and flow equalizing cavity 506; a plurality of circumferentially uniformly distributed gas through holes 508 are formed on the flow regulating orifice plate 507 to form a gas channel.

[0036] The gas flow from the annular gas distribution channel 301 first passes through the tapered flow regulating orifice plate 507, which guides the gas flow through its tapered structure, and the plurality of uniformly distributed gas through holes 508 divide the gas flow into multiple streams and re-mix them uniformly, achieving secondary flow regulation and distribution of the gas flow.

[0037] When the high-pressure gas flow passes through the flow regulating orifice plate 507, the gas flow is effectively eliminated and the gas flow pressure is balanced through the flow guiding effect of the tapered structure and the flow dividing effect of the uniformly distributed through holes, so that the gas enters the pressure stabilizing and flow equalizing cavity 506 more smoothly, and finally forms a uniform and stable gas distribution jet.

[0038] Preferably, the height of the flow guide cover 502 in the axial direction of the outer tube 100 is lower than the height of the drill beads 509 arranged on the drill bit 500. The core function of this structure is to preferentially ensure that the drill beads 509 effectively break the rock formation, while avoiding direct wear or interference of the flow guide cover 502 during drilling.

[0039] The flow guide cover 502 is fixedly installed inside the drill bit 500, and the height of the top portion of the flow guide cover 502 in the axial direction of the outer tube 100 is lower than the protruding height of the drill beads 509 arranged on the drill bit 500, so that the drill beads 509 become the first component of the drill bit 500 to contact the rock formation.

[0040] When the drill bit 500 rotates and drills, the drill beads 509 at higher positions first contact and break the bottom rock, while the relatively inwardly recessed flow guide 502 is protected from direct scraping with the rock by the drill beads 509, and the gas distribution nozzle 505 on the flow guide 502 is always in an effective working position to stably play the flow guiding and debris cleaning functions.

[0041] Preferably, the flow guide 502 is provided with a flow guide surface; the flow guide surface extends in the axial and radial directions of the outer tube 100. The core function of this structure is to effectively guide the high-pressure gas flow through the flow guide surface extending in the specific direction, optimize the bottom hole flow field, and enhance the stirring and carrying capacity of the cuttings.

[0042] The flow guide 502 is provided with one or more flow guide surfaces that extend in the axial and radial directions of the outer tube 100, forming a spatial curved surface structure with an outlet direction pointing to the area of the debris discharge port 302.

[0043] The high-pressure gas sprayed from the gas distribution nozzle 505 is guided by the flow guide surface to generate velocity components in the axial and radial directions at the same time, forming a rotating upward gas flow that effectively covers a larger range of bottom hole area, efficiently sucking and guiding the cuttings to the debris discharge port 302.

[0044] Preferably, the flow guide 502 is provided with a flow guide surface that is a circular arc surface. The core function of this structure is to optimize the gas flow guiding effect through the circular arc flow guide surface, reduce the flow resistance, form a more concentrated gas jet, and improve the cleaning efficiency of the bottom hole cuttings.

[0045] The flow guide surface of the flow guide 502 is in the shape of a circular arc surface, which smoothly transitions along the gas flow direction, and the center of curvature is directed towards the gas flow injection direction, enabling continuous guidance of the gas flow.

[0046] In operation, when the high-pressure gas flows along the circular arc flow guide surface, it forms a converging effect under the guidance of the curved surface, the gas flow direction is smoothly changed, the energy loss is small, and finally a concentrated and stable gas jet is formed, effectively impacting the bottom hole cuttings.

[0047] Preferably, the debris conveying mechanism 600 of the debris guide pipe 300 is a spiral conveying rod or a pneumatic conveying pipe. The core function of this structure is to continuously convey the bottom hole broken cuttings to the ground through mechanical or pneumatic conveying, ensuring smooth drilling.

[0048] The debris conveying mechanism 600 is axially arranged in the debris guide channel 303 inside the debris guide pipe 300, and can be in the form of a spiral conveying rod or a pneumatic conveying pipe; the spiral conveying rod has a continuous spiral blade structure, and the pneumatic conveying pipe is a hollow pipe structure and is in communication with a high-pressure gas source.

[0049] When the screw conveying rod is used, the cuttings are pushed upward along the slag guide channel 303 by the rotating movement; when the pneumatic conveying pipe is used, the cuttings are sucked into the pipe by the negative pressure generated by the high-speed airflow and conveyed to the ground; both of the two ways can realize the continuous removal of the cuttings. In addition, the chain scraper conveying mechanism, the hydraulic conveying pipe driven by the mud pump or the screw extrusion mechanism driven by the hole bottom motor can also be used to realize the mechanical lifting of the cuttings.

[0050] Preferably, a throttle orifice plate 503 is arranged inside the gas distribution nozzle 505, and the throttle orifice plate 503 is provided with throttle orifices with a smaller diameter than the passageway of the gas distribution nozzle 505. The core function of this structure is to accelerate the airflow of the nozzle twice through the throttle orifice plate 503 to form a high-speed jet, thereby enhancing the impact and suction capacity on the cuttings at the bottom of the hole.

[0051] The throttle orifice plate 503 is fixedly installed inside the gas distribution nozzle 505, and the flow cross section of the throttle orifice plate 503 is smaller than the original passageway of the gas distribution nozzle 505; the throttle orifices provided on the throttle orifice plate 503 are single or multiple small-diameter channels for constraining and concentrating the airflow.

[0052] When the high-pressure gas flows through the gas distribution nozzle 505, the gas pressure can be converted into kinetic energy through the diameter contraction effect of the throttle orifice plate 503, the flow rate is significantly increased, a high-speed focused jet is formed, and the cuttings at the bottom of the hole can be more effectively impacted and stirred, and the cuttings can be sucked into the slag guide channel 303.

[0053] Preferably, a slag collector is arranged at the slag suction port 304. The core function of this structure is to efficiently collect the broken cuttings at the bottom of the hole through the slag collector, and guide the cuttings into the slag guide channel 303, so as to prevent the cuttings from accumulating at the bottom of the hole and improve the slag removal efficiency.

[0054] The slag collector is fixedly installed at the inlet of the bottom end of the slag guide pipe 300, and the structure is in the shape of a bell mouth or a funnel, and the inlet diameter is larger than the passageway diameter of the slag guide pipe 300 to expand the cuttings collection range.

[0055] The cuttings stirred and carried by the high-pressure airflow move to the inlet of the slag collector under the action of the fluid at the bottom of the hole, are guided and converged through the bell mouth structure, and then smoothly enter the inside of the slag guide channel 303, and are continuously conveyed to the ground by the cuttings conveying mechanism 600.

[0056] Preferably, the slag collector is in the shape of a bell mouth, and a wear-resistant alloy layer is coated on the inner surface thereof. The core function of this structure is to expand the cuttings collection range through the bell mouth-shaped slag collector, and to resist the erosion and wear of the high-speed cuttings by using the wear-resistant alloy layer, thereby significantly improving the service life and reliability of the slag collector.

[0057] The slag collector is in the shape of a bell mouth, and the inlet diameter is significantly larger than the passageway diameter of the slag guide pipe 300; the entire inner surface of the slag collector is firmly coated with a high-hardness wear-resistant alloy layer to form an anti-abrasion protective surface.

[0058] High-speed moving debris is impacted on the inner surface of the slag collector under the entrainment of the airflow, and the wear-resistant alloy layer effectively resists the continuous erosion and abrasion of the debris, ensuring that the horn structure remains intact for a long time, thereby continuously and efficiently collecting and guiding the dispersed debris into the slag guiding channel 303.

[0059] The device forms an annular gas distribution channel 301 based on the outer pipe 100 and the slag guiding pipe 300 coaxially arranged inside the outer pipe 100, and communicates with the gas inlet 200, realizing stable delivery of high-pressure gas along the annular space to provide a uniform gas distribution basis for the down-the-hole hammer; the gas distribution power mechanism 400 drives the gas distribution piston 402 to reciprocate in the annular gas distribution channel 301 by the gas supply machine 401, forming a periodic pressure pulse airflow to efficiently drive the down-the-hole hammer to impact and break the rock stratum; the outer shell 501 and the flow guide cover 502 in the drill bit 500 form an annular chamber 504, and the flow guide cover 502 is provided with a gas distribution nozzle 505 corresponding to the slag discharge port 302 in the direction of injection, so that the high-pressure gas is injected into the bottom of the slag guiding channel 303 in a directional manner, effectively stirring and carrying the debris; the drill cuttings conveying mechanism 600 is axially arranged in the slag guiding channel 303, which can continuously convey the broken debris to the ground to avoid the accumulation of debris at the bottom of the hole. In addition, the annular gas distribution channel 301 and the annular chamber 504 are connected by the pressure stabilizing and flow equalizing cavity 506 added based on the drill bit 500, realizing pressure stabilization and preliminary flow equalization of the high-pressure gas and improving the pressure stability of the airflow entering the interior of the drill bit 500; the rectifier orifice plate 507 is arranged between the annular gas distribution channel 301 and the pressure stabilizing and flow equalizing cavity 506, and the conical structure and the uniformly distributed gas through holes 508 further guide and evenly distribute the airflow, ensuring that the gas is stably delivered to the gas distribution nozzle 505. Through the integrated structure design of gas distribution and slag guiding, as well as the pressure stabilization and flow rectification, the present application realizes the synergistic operation of efficient gas utilization and continuous removal of debris, and enhances the impact stability and rock breaking efficiency of the down-the-hole hammer.

[0060] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0061] In addition, the terms "first", "second", etc. are used only for the purpose of description, and should not be understood as indicating or implying relative importance or an indicated number of technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0062] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of various changes or replacements within the technical scope disclosed by the present application, which should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling, characterized in that, include: An outer tube (100) is provided with an air inlet (200); A slag guide pipe (300) is coaxially disposed inside the outer pipe (100), and an annular gas distribution channel (301) is formed between the slag guide pipe (300) and the outer pipe (100). The annular gas distribution channel (301) is connected to the air inlet (200). A slag discharge port (302) is provided on the side of the slag guide pipe (300) near the ground surface, and a slag suction port (304) is provided at the bottom of the slag guide pipe (300). The interior of the slag guide pipe (300) forms a slag guide channel (303) for conveying crushed rock cuttings. The gas distribution power mechanism (400) includes a gas supply machine (401) and a gas distribution piston (402) connected to the output end of the gas supply machine (401). The gas distribution piston (402) slides back and forth within the annular gas distribution channel (301). A drill bit (500) is connected to the outer tube (100) and is used to break rock strata. The drill bit (500) is provided with a shell (501) and a flow guide (502) supported and driven by the drill bit (500). An annular chamber (504) is formed between the shell (501) and the flow guide (502). The flow guide (502) is provided with at least one air distribution nozzle (505), and the spray direction of the air distribution nozzle (505) corresponds to the slag suction port (304). A cuttings conveying mechanism (600) is provided in the cuttings channel (303) and extends along the axial direction of the cuttings pipe (300), and is used to convey cuttings to the surface. The gas flows sequentially through the annular gas distribution channel (301), the annular chamber (504), the gas distribution nozzle (505), the slag suction port (304), the slag guiding channel (303), the slag discharge port (302), and the external environment.

2. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 1, characterized in that, The drill bit (500) also includes a pressure stabilizing and flow equalizing cavity (506) for connecting the annular gas distribution channel (301) with the annular chamber (504).

3. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 2, characterized in that, The drill bit (500) also includes at least one flow rectifier plate (507); the flow rectifier plate (507) is disposed between the annular gas distribution channel (301) and the pressure stabilizing and flow equalizing cavity (506); the cross-section of the flow rectifier plate (507) is a conical structure; the flow rectifier plate (507) has a plurality of evenly distributed gas through holes (508) for guiding and evenly distributing the airflow.

4. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 1, characterized in that, The height of the flow guide (502) along the axial direction of the outer tube (100) is lower than the height of the drill ball (509) provided on the drill bit (500).

5. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 4, characterized in that, The flow guide (502) extends along the axial and radial directions of the outer tube (100).

6. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 5, characterized in that, The flow guide (502) is provided with a flow guide surface; the flow guide surface is an arc surface.

7. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 1, characterized in that, The cuttings conveying mechanism (600) of the cuttings guide pipe (300) is a screw conveyor or a pneumatic conveying pipe.

8. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 1, characterized in that, The gas distribution nozzle (505) is provided with a throttling orifice plate (503), and the throttling orifice plate (503) has a throttling orifice with a diameter smaller than that of the gas distribution nozzle (505).

9. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 1, characterized in that, The slag suction port (304) is equipped with a slag collector.

10. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 9, characterized in that, The slag collector is funnel-shaped, and its inner surface is coated with a wear-resistant alloy layer.

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