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

Abstract

The present invention discloses a gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling, comprising an outer tube and a center tube, wherein the center tube is inserted in the outer tube, an annular gas distribution channel is formed between the inner wall of the outer tube and the outer wall of the center tube, a gas distribution joint is connected to the side wall of the outer tube corresponding to the gas distribution joint, a plurality of vents are provided on the side wall of the outer tube, the gas distribution joint is connected to the annular gas distribution channel through the plurality of vents, the gas distribution joint can be connected to the external gas transmission channel, the external input high-pressure gas can enter the annular gas distribution channel through the gas distribution joint, the top of the center tube is connected to a spherical slag guiding bin, the spherical slag guiding bin is connected to a shooting and suction slag guiding pipe, and the drilling slag passing through the inner cavity of the center tube can be discharged from the shooting and suction slag guiding pipe through the spherical slag guiding bin. Beneficial effect: the reverse circulation of the drilling tool system can be formed more stably and powerfully, thereby improving the slag discharge efficiency, reducing repeated crushing, and achieving the purpose of rapid drilling. The service life of the slag guiding bin is improved.

Description

Technical Field

[0001] The invention relates to a gas distribution and slag guiding device, in particular to a gas distribution and slag guiding device used for reverse circulation down-the-hole hammer drilling. Background Art

[0002] At present, rapid drilling and pile formation is an effective technical method in the treatment of broken strata such as large landslides. The reverse circulation casing drilling technology of down-the-hole hammer is suitable for drilling construction in broken strata. Based on the research and development of casing drill bits, reverse circulation down-the-hole hammers, dual-channel reverse circulation drill rods, pipe boots, and casings, in order to solve the technical problem that the negative pressure formed by the suction holes on the drill bit alone could not adapt to the large diameter, deep pile hole, and large amount of drilling slag in large landslides, the reverse circulation down-the-hole hammer gas distribution and slag guide device was developed. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problem that the negative pressure formed by the suction holes on the drill bit alone is difficult to adapt to the large diameter of the piles, the deep pile holes and the large amount of slag discharged from the drilling holes in large landslides, and to provide a gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling.

[0004] The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling provided by the present invention comprises an outer tube and a center tube, wherein the center tube is inserted in the outer tube, an annular gas distribution channel is formed between the inner wall of the outer tube and the outer wall of the center tube, a gas distribution joint is connected to the side wall of the outer tube, a plurality of air vents are opened on the side wall of the outer tube corresponding to the gas distribution joint, the gas distribution joint is connected to the annular gas distribution channel through the plurality of air vents, the gas distribution joint can be connected to the external gas transmission channel, and the high-pressure gas input from the outside can enter the annular gas distribution channel through the gas distribution joint, the top end of the center tube is connected to a spherical slag guiding bin, the spherical slag guiding bin is connected to a shooting and suction slag guiding pipe, and the drilling cuttings passing through the inner cavity of the center tube can be discharged from the shooting and suction slag guiding pipe through the spherical slag guiding bin.

[0005] The top end of the center tube is sealed with the outer tube by a sealing ring, the lower end of the center tube is threadedly connected to the inner tube joint, the top end of the center tube is connected to the spherical slag guide bin through a flange and a connecting pipe, a step is provided inside the flange to limit the axial movement of the center tube, and a sealing ring and a felt ring are provided inside the flange for dust-proof sealing between the flange and the center tube.

[0006] The lower end of the outer tube is screwed to the top of the dual-channel reverse circulation drill pipe, and tapered roller bearings are arranged on both sides of the middle step of the outer tube to bear radial force and axial force. An oil retaining ring is arranged on the inner side of the tapered roller bearing. A gas distribution sleeve is arranged on the middle shaft section of the outer tube, and the gas distribution sleeve and the outer tube are sealed by a sealing ring. The gas distribution sleeve and the gas distribution joint are screwed, and the gas distribution joint is fixedly connected to the outer tube by a gland and screws. An annular gas distribution space is formed between the gas distribution sleeve and the outer tube, and the annular gas distribution space corresponds to the vent hole on the outer tube, and the annular gas distribution space is connected to the annular gas distribution vent through the vent hole. The two channels are interconnected, an outer sleeve is also provided on the outer tube, an oil cup is provided on the outer sleeve, the oil cup is used for lubrication of the tapered roller bearing and the sealing ring, the upper and lower ends of the outer tube are respectively screwed with an upper end cover and a lower end cover, the upper end cover and the lower end cover are connected to the outer sleeve by screws, adjustment gaskets are provided between the upper end cover, the lower end cover and the end face of the outer tube, the adjustment gasket is used for fixing and pre-tightening the position of the tapered roller bearing, sealing rings and felt rings are provided on the upper end cover and the lower end cover for dustproof sealing between the upper end cover, the lower end cover and the outer tube, and the upper end cover is connected to the flange by screws.

[0007] A sleeve is provided on the shooting and suction slag guiding pipe, and an annular jet chamber is formed between the inner wall of the sleeve and the outer wall of the shooting and suction slag guiding pipe. A number of inclined jet holes are opened on the outer wall of the shooting and suction slag guiding pipe corresponding to the annular jet chamber, and the inner cavity of the shooting and suction slag guiding pipe is connected with the annular jet chamber through the jet holes. The annular jet chamber is also connected with an air intake pipe, and high-pressure gas is input from the annular jet chamber and the jet holes into the inner cavity of the shooting and suction slag guiding pipe through the air intake pipe.

[0008] Two lifting lugs are connected to the outer sleeve of the outer tube, and two lifting rods are connected to the two lifting lugs. The top ends of the two lifting rods are connected through a lifting shaft. When the drilling rig is drilling, the lifting shaft is connected to the wire rope on the winch.

[0009] Working principle of the present invention:

[0010] The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling provided by the present invention is connected to the lifting shaft with the winch wire rope on the drilling rig to suspend the drilling tool when in use, the lower end of the outer tube is screwed with the double-channel reverse circulation drill rod, and the lower part of the double-channel reverse circulation drill rod is screwed with the down-the-hole hammer. The high-pressure hose connected to the air compressor is screwed with the gas distribution joint, and another high-pressure hose connected to the air compressor is screwed with the air intake pipe on the annular jet chamber.

[0011] During drilling, the drilling rig's rotary system drives the reverse circulation dual-channel drill pipe and the down-the-hole hammer to rotate. The high-pressure gas generated by the air compressor enters the annular gas distribution channel formed between the central tube and the outer tube through the gas distribution joint and then enters the down-the-hole hammer to drive the reverse circulation down-the-hole hammer to work. The crushed rock debris enters the central channel of the reverse circulation dual-channel drill pipe through the reverse circulation drill bit. The rock debris continues to return to the inner cavity of the central tube and then enters the spherical debris guide bin. At this time, high-pressure gas is input into the annular jet bin, so that a strong negative pressure is generated in the inner cavity of the jet suction slag guide pipe, and the rock debris in the spherical slag guide bin and even some large-grained rock debris in the dual-channel drill pipe are sucked into the jet suction slag guide pipe. Under the action of airflow and gravity, the rock debris enters the slag discharge hose and is discharged to the surface.

[0012] The structure of the spherical slag guide bin can form a flow field that is easy to discharge slag and reduces wear on the bin wall. Compared with the curved pipe structure used before, it can greatly increase the service life.

[0013] The high-pressure gas input from the annular jet chamber generates a strong negative pressure in the inner cavity of the jet suction slag pipe, which can greatly improve the slag discharge efficiency and reduce repeated crushing, and play an important role in the stable formation of reverse circulation and the cooling of the drill bit; especially under the conditions of large drilling diameter, large drilling depth and formation crushing requiring casing drilling, the jet slag guiding technology will be the key to the smooth progress of drilling.

[0014] Beneficial effects of the present invention:

[0015] The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling provided by the present invention is suitable for drilling construction in broken strata. Together with the pipe drill bit, reverse circulation down-the-hole hammer, dual-channel reverse circulation drill rod, pipe boot, casing, etc., a complete drilling tool system is formed. It can make the formation of reverse circulation of the drilling tool system more stable and powerful, thereby improving the slag discharge efficiency, reducing repeated crushing, and achieving the purpose of rapid drilling. The flow field that is conducive to slag discharge formed in the spherical slag guiding bin can reduce the wear of the rock slag on the inner wall of the spherical slag guiding bin, thereby increasing the service life of the slag guiding bin. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the gas distribution and slag guiding device described in the present invention.

[0017] Figure 2 It is a schematic diagram of the cross-sectional structure of the gas distribution and slag guiding device described in the present invention.

[0018] The annotations in the above figure are as follows:

[0019] 1. Outer tube 2. Center tube 3. Annular gas distribution channel 4. Gas distribution joint

[0020] 5. Ventilation hole 6. Spherical slag guide bin 7. Slag guide pipe 8. Internal pipe joint

[0021] 9. Flange 10. Connecting pipe 11. Tapered roller bearing 12. Gas sleeve 13. Jacket

[0022] 14, oil cup 15, upper end cover 16, lower end cover 17, sleeve 18, annular jet chamber

[0023] 19, jet hole 20, air inlet pipe 21, hanging ear column 22, lifting rod 23, lifting shaft. DETAILED DESCRIPTION

[0024] See also Figure 1 to Figure 2 As shown:

[0025] The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling provided by the present invention comprises an outer tube 1 and a center tube 2, wherein the center tube 2 is inserted in the outer tube 1, and an annular gas distribution channel 3 is formed between the inner wall of the outer tube 1 and the outer wall of the center tube 2. A gas distribution joint 4 is connected to the side wall of the outer tube 1, and a plurality of air vents 5 are opened on the side wall of the outer tube 1 corresponding to the gas distribution joint 4. The gas distribution joint 4 is connected to the annular gas distribution channel 3 through the plurality of air vents 5. The gas distribution joint 4 can be connected to an external gas transmission channel, and the high-pressure gas input from the outside can enter the annular gas distribution channel 3 through the gas distribution joint 4. The top end of the center tube 2 is connected to a spherical slag guiding bin 6, and the spherical slag guiding bin 6 is connected to a shooting and suction slag guiding pipe 7. The drilling slag passing through the inner cavity of the center tube 2 can be discharged from the shooting and suction slag guiding pipe 7 through the spherical slag guiding bin 6.

[0026] The top end of the center tube 2 is sealed with the outer tube 1 by a sealing ring, the lower end of the center tube 2 is threadedly connected to the inner tube joint 8, the top end of the center tube 2 is connected to the spherical slag guide bin 6 through a flange 9 and a connecting pipe 10, a step is provided inside the flange 9 to limit the axial movement of the center tube 2, and a sealing ring and a felt ring are provided inside the flange 9 for dust-proof sealing between the flange 9 and the center tube 2.

[0027] The lower end of the outer tube 1 is screwed to the top of the dual-channel reverse circulation drill pipe. Tapered roller bearings 11 are provided on both sides of the middle step of the outer tube 1 to bear radial force and axial force. An oil retaining ring is provided on the inner side of the tapered roller bearing 11. A gas distribution sleeve 12 is provided on the middle shaft section of the outer tube 1. The gas distribution sleeve 12 and the outer tube 1 are sealed by a sealing ring. The gas distribution sleeve 12 is screwed to the gas distribution joint 4. The gas distribution joint 4 is fixedly connected to the outer tube 1 by a gland and screws. An annular gas distribution space is formed between the gas distribution sleeve 12 and the outer tube 1. The annular gas distribution space corresponds to the vent hole 5 on the outer tube 1. The annular gas distribution space is connected to the annular gas distribution channel 3 through the vent hole 5. The outer tube 1 An outer sleeve 13 is also provided on the upper part, and an oil cup 14 is provided on the outer sleeve 13. The oil cup 14 is used for lubrication of the tapered roller bearing 11 and the sealing ring. The upper end and the lower end of the outer tube 1 are respectively screwed with an upper end cover 15 and a lower end cover 16. The upper end cover 15 and the lower end cover 16 are connected to the outer sleeve 13 by screws. Adjustment gaskets are provided between the upper end cover 15 and the lower end cover 16 and the end surface of the outer tube 1. The adjustment gaskets are used to fix and pre-tighten the position of the tapered roller bearing 11. The upper end cover 15 and the lower end cover 16 are provided with sealing rings and felt rings for dustproof sealing between the upper end cover 15 and the lower end cover 16 and the outer tube 1. The upper end cover 15 is connected to the flange 9 by screws.

[0028] A sleeve 17 is sleeved on the slag-shooting and suction guiding tube 7, and an annular jet chamber 18 is formed between the inner wall of the sleeve 17 and the outer wall of the slag-shooting and suction guiding tube 7. A number of inclined jet holes 19 are opened on the outer wall of the slag-shooting and suction guiding tube 7 corresponding to the annular jet chamber 18. The inner cavity of the slag-shooting and suction guiding tube 7 is connected with the annular jet chamber 18 through the jet holes 19. The annular jet chamber 18 is also connected with an air inlet pipe 20. High-pressure gas is input from the annular jet chamber 18 and the jet holes 19 into the inner cavity of the slag-shooting and suction guiding tube 7 through the air inlet pipe 20.

[0029] Two lifting lugs 21 are connected to the outer sleeve 13 of the outer tube 1, and two lifting rods 22 are connected to the two lifting lugs 21. The top ends of the two lifting rods 22 are connected by a lifting shaft 23. When the drilling rig is drilling, the lifting shaft 23 is connected to the wire rope on the winch.

[0030] Working principle of the present invention:

[0031] When in use, the gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling provided by the present invention has a lifting shaft 23 connected to a winch wire rope on a drilling rig to suspend the drilling tool, the lower end of the outer tube 1 is screwed to a double-channel reverse circulation drill rod, and the lower end of the double-channel reverse circulation drill rod is screwed to a down-the-hole hammer. A high-pressure hose connected to an air compressor is screwed to a gas distribution joint 4, and another high-pressure hose connected to the air compressor is screwed to an air intake pipe 20 on an annular jet chamber 18.

[0032] During drilling, the drilling rig rotation system drives the reverse circulation dual-channel drill pipe and the down-the-hole hammer to rotate, and the high-pressure gas generated by the air compressor enters the annular gas distribution channel 3 formed between the central tube 2 and the outer tube 1 through the gas distribution joint 4, and then enters the down-the-hole hammer to drive the reverse circulation down-the-hole hammer to work. The crushed rock slag enters the central channel of the reverse circulation dual-channel drill pipe through the reverse circulation drill bit, and the rock slag continues to return to the inner cavity of the central tube 2 and then enters the spherical slag guide bin 6. At this time, high-pressure gas is input into the annular jet bin 18, so that a strong negative pressure is generated in the inner cavity of the jet suction slag guide pipe 7, and the rock slag in the spherical slag guide bin 6 and even some large-particle rock slag in the dual-channel drill pipe are sucked into the jet suction slag guide pipe 7. Under the action of airflow and gravity, the rock slag enters the slag discharge hose and is discharged to the surface.

[0033] The structure of the spherical slag guide bin 6 can form a flow field that is easy to discharge slag and reduces the wear of the bin wall, and can greatly increase the service life compared to the curved pipe structure used previously.

[0034] The high-pressure gas input from the annular jet chamber 6 generates a strong negative pressure in the inner cavity of the jet suction slag guide pipe 7, which can greatly improve the slag discharge efficiency and reduce repeated crushing, and play an important role in the stable formation of reverse circulation and the cooling of the drill bit; especially under the conditions of large drilling diameter, large drilling depth and formation crushing requiring casing drilling, the jet slag guide technology will be the key to whether the drilling can proceed smoothly.

Claims

1. A gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling, comprising an outer tube and a center tube, wherein the center tube is inserted in the outer tube, an annular gas distribution channel is formed between the inner wall of the outer tube and the outer wall of the center tube, a gas distribution joint is connected to the side wall of the outer tube, a plurality of vents are opened on the side wall of the outer tube corresponding to the gas distribution joint, the gas distribution joint is connected to the annular gas distribution channel through the plurality of vents, the gas distribution joint can be connected to an external gas transmission channel, and the high-pressure gas input from the outside can enter the annular gas distribution channel through the gas distribution joint, the top end of the center tube is connected to a spherical slag guiding bin, the spherical slag guiding bin is connected to a shooting and suction slag guiding pipe, and the drilling slag passing through the inner cavity of the center tube can be discharged from the shooting and suction slag guiding pipe through the spherical slag guiding bin, characterized in that: The top end of the center tube is sealed with the outer tube by a sealing ring, the lower end of the center tube is threadedly connected to the inner tube joint, the top end of the center tube is connected to the spherical slag guide bin by a flange and a connecting pipe, a step is provided inside the flange to limit the axial movement of the center tube, and a sealing ring and a felt ring are provided inside the flange to seal against dust between the flange and the center tube; a sleeve is provided on the shooting and suction slag guide tube, an annular jet bin is formed between the inner wall of the sleeve and the outer wall of the shooting and suction slag guide tube, a number of inclined jet holes are provided on the outer wall of the shooting and suction slag guide tube corresponding to the annular jet bin, the inner cavity of the shooting and suction slag guide tube is connected with the annular jet bin through the jet holes, and an air inlet pipe is also connected to the annular jet bin, and high-pressure gas is input from the annular jet bin and the jet holes into the inner cavity of the shooting and suction slag guide tube through the air inlet pipe.

2. The gas distribution and slag guiding device for reverse circulation down-the-hole hammer drilling according to claim 1, characterized in that: The lower end of the outer tube is screwed to the top of the dual-channel reverse circulation drill pipe, tapered roller bearings are arranged on both sides of the middle step of the outer tube to bear radial force and axial force, an oil retaining ring is arranged on the inner side of the tapered roller bearing, a gas distribution sleeve is arranged on the middle shaft section of the outer tube, the gas distribution sleeve and the outer tube are sealed by a sealing ring, the gas distribution sleeve and the gas distribution joint are screwed, the gas distribution joint is fixedly connected to the outer tube by a gland and screws, an annular gas distribution space is formed between the gas distribution sleeve and the outer tube, the annular gas distribution space corresponds to the vent hole on the outer tube, and the annular gas distribution space is connected to the annular distribution through the vent hole. The air channels are interconnected, and an outer sleeve is also provided on the outer tube. An oil cup is provided on the outer sleeve, and the oil cup is used for lubrication of the tapered roller bearing and the sealing ring. The upper and lower ends of the outer tube are respectively screwed with an upper end cover and a lower end cover, and the upper end cover and the lower end cover are connected to the outer sleeve by screws. Adjustment gaskets are provided between the upper end cover, the lower end cover and the end face of the outer tube, and the adjustment gaskets are used for fixing and pre-tightening the position of the tapered roller bearing. Sealing rings and felt rings are provided on the upper end cover and the lower end cover for dustproof sealing between the upper end cover and the lower end cover and the outer tube, and the upper end cover is connected to the flange by screws.

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