Quantitative air distribution foam dust removal device, air drilling system and drilling process

Abstract

The application discloses a quantitative air distribution foam dust removal device, an air drilling system and a drilling process. The quantitative air distribution foam dust removal device comprises a sleeved first pipe body and a second pipe body, forms an annular space gap, and is open at one end; an axially communicating channel and a radially communicating channel are inlaid in the pipe wall of the first pipe body at the open end, and the radially communicating channel is communicated with the annular space gap; a quantitative air distribution structure is arranged on the second pipe body at the open end, so as to limit the quantitative air into the annular space gap; and a foam outlet communicated with the annular space gap is arranged on the pipe wall of the first pipe body at the non-open end. The scheme realizes the continuous dust capturing and removing function in the dust production point at the hole bottom and in the process that the dust-containing airflow returns to the orifice from the annular space during the air drilling process. Through the quantitative air distribution foam dust removal device, the foam can be stably and efficiently generated under different air volumes and air pressures.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of coal mine drilling engineering, in particular to a quantitative air distribution foam dust removal device, an air drilling system and a drilling process. BACKGROUND

[0002] With the deep mining of coal mines in China, the proportion of high-gas broken and soft coal seams is increasing. In broken and soft coal seam drilling, air drilling has the advantages of high slag removal efficiency, which is beneficial to the stability of the hole wall, and improves the drilling depth and hole completion rate. It is currently the main drilling method for broken and soft coal seams. The biggest disadvantage of air drilling is that the coal dust is high-speed, small-grained and fast-diffusing after exiting the hole, which is seriously polluting and difficult to control. Therefore, it is difficult to collect and remove dust at the hole. Foam has the advantages of lubrication, good dust capture and powder removal effect, and small environmental pollution. In wet, water-sensitive and unstable formations, foam has unique advantages in powder removal. In air drilling, the quantitative air distribution foam dust removal device can generate foam stably and efficiently under different air volume and pressure. It can combine with fine coal dust at the dust production point at the bottom of the hole and in the process of dust-containing airflow returning to the hole from the annulus to become larger coal dust, playing a continuous dust capture role, reducing the difficulty of hole dust removal, facilitating the continuous drilling work, and avoiding threats to the life and health of underground workers. Therefore, there is a practical need for research on foam dust removal technology and corresponding devices in air drilling. SUMMARY

[0003] The present application solves the problem of high-speed, fast-diffusing, small-grained and serious pollution of coal dust after exiting the hole, which is difficult to control and threatens the life and health of underground workers. A quantitative air distribution foam dust removal device, an air drilling system and a drilling process are provided to realize continuous dust capture at the dust production point at the bottom of the hole and in the process of dust-containing airflow returning to the hole from the annulus during air drilling, and reduce the difficulty of hole dust removal.

[0004] To solve the above problems, the technical scheme adopted by the present application is as follows:

[0005] A quantitative air distribution foam dust removal device comprises: a first pipe body and a second pipe body sleeved to form an annular gap, and one end is open; an axial channel and a radial channel are embedded in the pipe wall of the first pipe body at the open end, and the radial channel is communicated with the annular gap; a quantitative air distribution structure is arranged on the second pipe body at the open end to limit the quantitative air entering the annular gap; a foam outlet is arranged on the pipe wall of the first pipe body at the non-open end and communicated with the annular gap.

[0006] Optionally, the quantitative air distribution structure comprises: a limiting surface ring clamped in the open end of the first pipe body; a baffle and a spring are arranged in the open end of the second pipe body in sequence; the inner diameter of the limiting surface ring gradually decreases from the open end, and the baffle moves back and forth in the annular space of the limiting surface ring.

[0007] Optionally, an axial baffle ring is attached to the front end of the wind shield; an axial guide groove is arranged on the wall of the second pipe body, and the wind shield is clamped to the axial guide groove.

[0008] Optionally, a spiral blade is arranged outside the second pipe body at the rear end of the air-quantity-regulating structure.

[0009] Optionally, a first-stage foamer and a second-stage foamer are arranged in sequence at the closed end of the annular space gap.

[0010] Optionally, an adapter is arranged on the open end of the first pipe body in an axial manner.

[0011] An air drilling system is provided with a drill bit, an air-quantity-regulating foam dust removal device, an air screw motor, a lower non-magnetic drill pipe, a probe battery cylinder, an upper non-magnetic drill pipe, a spiral drill pipe and a water channel arranged in sequence; the air-quantity-regulating foam dust removal device is any one of the air-quantity-regulating foam dust removal devices described in the application; the water channel is connected with a wind supply assembly and a foam supply assembly respectively.

[0012] Optionally, the wind supply assembly is provided with a high-pressure rubber pipe, a first flowmeter, a compressed air pipeline and an air compressor.

[0013] Optionally, the foam supply assembly is provided with a foam liquid pipeline, a second flowmeter and a foam liquid pump.

[0014] An air drilling process is implemented by using any one of the air drilling systems described in the application, and comprises the following steps: in the first step, a drill bit, an air-quantity-regulating foam dust removal device, an air screw motor, a lower non-magnetic drill pipe, a probe battery cylinder, an upper non-magnetic drill pipe and a spiral drill pipe are connected in sequence;

[0015] In the second step, the connected spiral drill pipe is connected to the air compressor through the air inlet of the water channel and the high-pressure rubber pipe and the compressed air pipeline, a pressure relief valve is arranged at the end of the water channel, a first flowmeter and a stop valve are arranged between the high-pressure rubber pipe and the compressed air pipeline; at the same time, the foam liquid pipeline is connected to the foam liquid pump through the foam liquid inlet of the water channel, and a second flowmeter is arranged between the foam liquid pipeline and the foam liquid pump;

[0016] In the third step, the air compressor is started to supply air, the compressed air passes through the compressed air pipeline, the stop valve, the first flowmeter, the high-pressure rubber pipe, the water channel, the spiral drill pipe, the upper non-magnetic drill pipe, the probe battery cylinder, the lower non-magnetic drill pipe and the air screw motor, and then enters the air-quantity-regulating foam dust removal device, a small amount of air is distributed to the annular space gap for generating foam, and the remaining air is discharged through the drill bit for carrying residue.

[0017] Fourth step: open the foam pump to inject the foam, the foam passes through the second flow meter, foam pipeline, water, spiral drill pipe, upper non-magnetic drill pipe, probe pipe battery cylinder, lower non-magnetic drill pipe and air screw motor, then enters the annular gap through the annular groove, axial channel and radial channel, the foam is mixed with the quantitative air flowing in, and the gas-liquid mixture realizes gas-liquid mixing along the spiral blade, and then passes through the primary foaming device and the secondary foaming device, and then flows out from the foam outlet.

[0018] The beneficial effects of the present application are:

[0019] (1) The continuous dust capture and removal function in the process of air drilling at the dust production point at the bottom of the hole and in the process of dust-containing air flow returning to the hole from the annulus is realized.

[0020] (2) Through the quantitative foam dust removal device, stable and efficient foam can be generated under different air volume and air pressure.

[0021] (3) With the increase of drilling depth, the continuous dust capture time of the foam on the dust-containing air flow is longer, and the dust capture effect is better.

[0022] (4) The difficulty of hole mouth dust removal is reduced, which is beneficial to the continuous operation, and the threat to the life and health of the downhole operation personnel is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is a schematic diagram of the air drilling system of the present application;

[0024] Figure 2 is a schematic diagram of the quantitative air distribution foam dust removal device;

[0025] Figure 3 is Figure 2 is a first pipe body structure sectional view in

[0026] Figure 4 is Figure 2 is a second pipe body structure schematic diagram in

[0027] Figure 5 is Figure 4 is a sectional view of

[0028] Figure 6 is Figure 2 is an adapter structure schematic diagram in

[0029] Figure 7 is Figure 1 is a water channel structure schematic diagram in

[0030] Figure 8 is a quantitative air distribution principle formula derivation diagram;

[0031] 1-drill bit, 2-quantitative air distribution foam dust removal device, 3-air screw motor, 4-lower non-magnetic drill pipe, 5-probe battery tube, 6-upper non-magnetic drill pipe, 7-helix drill pipe, 8-water, 9-pressure relief valve, 10-high pressure rubber tube, 11-first flowmeter, 12-stop valve, 13-air pressure pipeline, 14-air compressor, 15-foam liquid pipeline, 16-second flowmeter, 17-foam pump;

[0032] 21-first pipe body, 211-axial channel, 212-radial channel, 213-foam outlet, 214-first pipe body pin, 215-annular groove, 216-step surface, 217-first pipe body box;

[0033] 22-second pipe body, 221-axial retaining ring, 222-wind shield, 223-spring, 224-spiral blade, 225-axial guide groove, 226-second pipe body pin, 227-second pipe body box, 228-wind shield installation groove, 229-second pipe body air inlet channel;

[0034] 23-face limiting ring, 24-first stage foaming device, 25-second stage foaming device;

[0035] 26-adaptor, 261-annular groove, 262-first adaptor box, 263-foam channel, 264-second adaptor box, 265-adaptor air inlet channel;

[0036] 81-foam liquid inlet, 82-foam liquid connector shell, 83-foam liquid channel, 84-foam liquid connector inner rod, 85-air connector, 86-air inlet, 87-water inlet air inlet channel, 88-water inlet pin;

[0037] S1 the left side annular cross-sectional area of the wind shield, S2 the annular cross-sectional area of the wind shield, S3 the right side annular cross-sectional area of the wind shield. DETAILED DESCRIPTION

[0038] The technical solutions of the present application are described below. It should be emphasized that in this disclosure, the orientation words such as "up, down, left, right, front, back" generally correspond to the up, down, left, right, front, back directions facing the drawings, where "up, down" correspond to the vertical direction or height direction, and "left, right" correspond to the horizontal direction. The "axis, radius" refers to the axial or radial direction of the pipe shaft component. However, the above orientation words are only used to explain and illustrate the disclosure and are not used for limitation.

[0039] The quantitative air distribution foam dust removal device of the present application is provided with:

[0040] In combination Figures 1-6The quantitative air distribution foam dust removal device of the present application comprises: a first pipe body 21 and a second pipe body 22 which are nested to form an annular space gap, wherein the annular space gap refers to the annular space generated after the two pipe bodies with different diameters are coaxially nested, and one end is open, wherein the open end refers to that there is no obvious sealing structure at the end, and the annular space gap is in communication with the external space; at the open end, an axial channel 211 and a radial channel 212 are embedded in the pipe wall of the first pipe body 21, and the radial channel 212 is in communication with the annular space gap, and the axial channel 211 is in communication with the channel of the pipe body connected to the front end; at the open end, a quantitative air distribution structure is arranged on the second pipe body 22, which mainly serves the purpose of uniform air distribution, and ensures that the air quantity entering the annular space gap is always uniform and quantitative, for example, a structure moving in the axial direction can be used to adjust the size of the air vent by controlling the length of the axial movement, thereby controlling the air inlet quantity and limiting the quantitative air entering the annular space gap; the stable air quantity entering the annular space gap can be mixed with the foam from the axial channel 211 and the radial channel 212, thereby generating a continuous and stable foam quantity to ensure the dust removal effect; a foam outlet 213 in communication with the annular space gap is arranged on the pipe wall of the first pipe body 21 at the non-open end, so that the generated foam directly passes to the bottom for dust removal; the axial channel of the second pipe body, i.e., the second pipe body air inlet channel 229, is the main channel for incoming air, and the inlet hole bottom is matched with the broken rock. The scheme of the present application realizes the continuous dust capture and removal function during the air drilling process at the dust production point at the bottom of the hole and in the process of returning the dust-containing airflow from the annular space to the hole opening. Through the quantitative air distribution foam dust removal device, stable and efficient foam generation can be realized under different air quantities and air pressures.

[0041] In the present disclosure, the quantitative air distribution structure comprises: a limiting ring 23 arranged in the open end of the first pipe body 21; a baffle 222 and a spring 223 arranged in the open end of the second pipe body 22 in sequence; the inner diameter of the limiting ring 23 gradually decreases from the open end, and the baffle 222 moves back and forth in the annular space of the limiting ring 23. The limiting ring 23 is externally connected to the step surface 216 by a thread, and the inside is a structure surface with a certain curvature. When the air supply quantity is small, the air pressure is small, the baffle 222 compresses the spring 223 with a small movement stroke, and the cross-sectional area of the quantitative air distribution device composed of the baffle 222 and the inside of the limiting ring 23 is large; when the air supply quantity is large, the air pressure is large, the baffle 222 compresses the spring 223 with a large movement stroke, and the cross-sectional area of the quantitative air distribution device composed of the baffle 222 and the inside of the limiting ring 23 is small; with the change of the air supply quantity, the quantitative air is always delivered to the gas-liquid mixing channel, thereby ensuring the stability of the foaming device.

[0042] In the present disclosure, the shaft stop ring 221 is attached to the front end of the wind shield 222 to further reinforce the wind shield 222; the axial guide groove 225 is arranged on the pipe wall of the second pipe body 22, and the wind shield 222 is clamped to the axial guide groove 225. The axial guide groove 225 is a notch groove extending in the axial direction, so that the movement distance of the wind shield 222 in the axial direction is limited within a certain range, and at least a minimum ventilation amount is ensured to prevent the air vent from being closed.

[0043] In the present disclosure, the spiral blade 224 is arranged outside the second pipe body 22 at the rear end of the quantitative air supply structure. The gas-liquid mixture enters the annular channel formed by the spiral blade 224, prolongs the gas-liquid mixing path, and ensures sufficient mixing and stirring of the gas-liquid.

[0044] In the present disclosure, the first-stage foamer 24 and the second-stage foamer 25 are arranged in sequence at the closed end of the annular space gap. The first-stage foamer 24 and the second-stage foamer 25 are both screen structures, and generally, the screen aperture of the first-stage foamer 24 is large, and the screen aperture of the second-stage foamer 25 is small. After passing through the first-stage foamer 24 and the second-stage foamer 25, the foam can generate more dense foam, and the dust removal effect is further improved.

[0045] In the present disclosure, the adapter 26 is arranged at the open end of the first pipe body 21 in a shaft connection manner. The connection mode is as follows: the first adapter female buckle 262 is connected with the drill rod male buckle, the second adapter female buckle 264 is connected with the first pipe body male buckle 214, the first pipe body female buckle 217 is connected with the second pipe body male buckle 226, at this time, the shaft stop ring 221 fixes the wind shield 222 to the left side of the second pipe body 22, the first-stage foamer 24 and the second-stage foamer 25 are located in the annular channel formed by the first pipe body 21 and the second pipe body 22 at the foam outlet 213 end; the limiting ring 23 is clamped on the stepped surface 216 of the first pipe body 21, and the annular groove 215 is arranged to communicate a plurality of axial channels 211 and ensure the conduction of the foam channel of the front end structure; the second pipe body female buckle 227 is connected with the drill bit at the rear end.

[0046] In combination Figure 1The air drilling system of the present application is provided with a drill bit 1, a quantitative air distribution foam dust removal device 2, an air screw motor 3, a lower non-magnetic drill pipe 4, a probe battery barrel 5, an upper non-magnetic drill pipe 6, a spiral drill pipe 7 and a water convenient 8 connected in sequence; the quantitative air distribution foam dust removal device 2 is any quantitative air distribution foam dust removal device 2 of the present application; the water convenient 8 is connected with a wind supply assembly and a foam supply assembly, specifically, a foam liquid inlet 81 is connected with the foam supply assembly and foam liquid is transported through a foam liquid channel 83; an air inlet 86 is used for connecting the wind supply assembly and a water convenient air inlet channel 87 forms a main air inlet channel. The connection mode of the water convenient 8 is that the water convenient 8 is composed of a foam liquid connector outer shell 82, a foam liquid connector inner rod 84 and an air connector 85 which are connected in sequence along the axis, a female screw of the foam liquid connector outer shell 82 is connected with a left male screw of the foam liquid connector inner rod 84 through a screw connection, a right male screw of the foam liquid connector inner rod 84 is connected with a female screw of the left air connector 85, and an air connector male screw 88 is used for connecting subsequent drill pipes and other structures.

[0047] In the present application, the wind supply assembly is provided with a high-pressure rubber tube 10, a first flow meter 11, a compressed air pipeline 13 and an air compressor 14, the water convenient 8 is provided with a pressure relief valve 9, and the first flow meter 11 and a stop valve 12 are arranged between the high-pressure rubber tube 10 and the compressed air pipeline 13.

[0048] In the present application, the foam supply assembly is provided with a foam liquid pipeline 15, a second flow meter 16 and a foam liquid pump 17.

[0049] The working principle of the quantitative air distribution foam dust removal device of the present application is as follows:

[0050] The foam liquid enters the water convenient 8 through the foam liquid inlet 81, is transmitted backward through the foam liquid channel 83 which is buried on the foam liquid connector inner rod 84 and the air connector 85 along the axial direction, enters the axial channel 211 and the radial channel 212 on the quantitative air distribution foam dust removal device 2 through the axial channels on the spiral drill pipe 7 and other components, enters the gas-liquid mixing channel formed by the first pipe body 21 and the second pipe body 22, the foam liquid in the mixing channel is mixed with the quantitative air flowing in through the air baffle 222 and the face limiting ring 23, the gas-liquid mixture enters the annular channel formed by the spiral blade 224, the gas-liquid mixing path is lengthened to ensure sufficient mixing and stirring of the gas and liquid, and then the foam liquid flows out through the foam outlet 213 after passing through the primary foaming device 24 and the more dense secondary foaming device 25, continuously captures dust during the air drilling at the dust production point on the hole bottom and in the process of the dust-containing airflow returning to the hole from the annulus, and as the hole depth increases, the mixing of the foam and the coal dust is more sufficient and the dust capturing effect is better. In this process, due to the screwing and unscrewing and wear of the drilling tools, it is impossible to ensure that the foam liquid channel is completely aligned, so the annular groove 215 is processed to ensure the smooth flow of the foam liquid, and the radial channel 212 is a through hole due to the need for processing, so the outside of the channel needs to be plugged after the processing is completed to ensure the smooth entry of the foam liquid into the mixing channel.

[0051] Wherein, the air entering the adapter head inlet channel 265, a part of which is quantitatively distributed into the gas-liquid mixing channel (annular space gap), and the other part enters the hole bottom matching rock fragments through the second pipe body inlet channel 229. The realization of the quantitative air distribution mechanism depends on the cooperation of the air baffle installation slot 228, the spring 223 and the limiting ring 23, as shown in Figure 2 and 8 As shown in the left side of the air baffle 222, the air baffle 222 and the right side of the air baffle 222, respectively, take three annular sections: a, b and c; list the Bernoulli equation between section a and section b:

[0052]

[0053] In the formula: P1, P2 are the static pressures of sections a, b, respectively, Pa;

[0054] V1, V2 are the average air velocities of sections a, b, respectively, m / s;

[0055] ρ is the average density of air, Kg / m 3 ;

[0056] ζ is the local resistance coefficient, which can be obtained from the table, for the case of sudden reduction of section,

[0057] Let the air volume passing through the annular section be Q, according to the fluid continuity equation:

[0058] Q = V1 S1 = V2 S2 (1-2);

[0059] In the formula: S1, S2 are the areas of sections a and b, respectively, m 2 ,

[0060] From formula 1-1 and 1-2, we can get:

[0061]

[0062] The annular space gap between section a and section c is selected as the control body, and the momentum equation of the fluid in the control body is:

[0063] P1S1-P3S3-F = ρQ(V3-V1) (1-4);

[0064] In the formula: S3 is the area of section c, m 2 ,

[0065] V3 is the planar velocity of section c, m / s;

[0066] F is the reaction force of the air baffle to the fluid, N.

[0067] When the fluid flows from the cross section b to the cross section c, the cross section suddenly expands, due to the existence of inertia, the flow beam cannot suddenly expand according to the shape of the pipeline, but like a jet, after leaving the small cross section, the flow beam passes a distance before the entire annular cross section is filled again, so:

[0068] V3 = V2, P3 = P2;

[0069] Since the wind deflector belongs to a thin plate structure, the cross sections a and c are very close, so S1 is approximately equal to S3, for the purpose of simplifying the calculation, it is assumed that S1 = S3 here.

[0070] Substitute V3 = V2, P3 = P2, S1 = S3 into formulas 1-4 to obtain:

[0071] (P1-P2)S1-F = rhoQ(V2-V1) (1-5);

[0072] Substitute formulas 1-2, 1-3 into formula 1-5 to obtain:

[0073]

[0074]

[0075] In the formula: r1 is the inner diameter of the wind deflector (constant), r2 is the outer radius of the wind deflector (constant), and r3 is the radius from the shaft center to the curved surface (variable).

[0076] Through the above-mentioned quantitative air distribution device, when the air supply is small, the air pressure is small, the wind deflector 222 compresses the spring 223 to have a small movement stroke, and the cross-sectional area S2 of the quantitative air distribution device composed of the wind deflector 222 and the inside of the limiting surface ring 23 is large; when the air supply is large, the air pressure is large, the wind deflector 222 compresses the spring 223 to have a large movement stroke, and the cross-sectional area S2 of the quantitative air distribution device composed of the wind deflector 222 and the inside of the limiting surface ring 23 is small; with the change of the air supply, the quantitative air is always delivered to the gas-liquid mixing channel, and the stability of the foaming device is ensured.

[0077] The air drilling process of the application is realized through an air drilling system, and specifically includes the following steps:

[0078] First step: sequentially connect the drill bit 1, the quantitative air distribution foam dust removal device 2, the air screw motor 3, the lower non-magnetic drill pipe 4, the probe battery cylinder 5, the upper non-magnetic drill pipe 6 and the spiral drill pipe 7;

[0079] Second step: the connected auger rod 7 is connected to the air compressor 14 through the air inlet of the water channel 8 and the high-pressure rubber pipe 10 and the compressed air pipe 13, the water channel 8 is provided with a pressure relief valve 9, the high-pressure rubber pipe 10 is provided with a first flow meter 11 and a stop valve 12 between the compressed air pipe 13; at the same time, the foam liquid pipe 15 is connected to the foam liquid pump 17 through the foam liquid inlet of the water channel 8, and a second flow meter 16 is arranged between the foam liquid pipe 15 and the foam liquid pump 17;

[0080] Third step: the air compressor 14 is turned on to supply air, the compressed air passes through the compressed air pipe 13, the stop valve 12, the first flow meter 11, the high-pressure rubber pipe 10, the water channel 8, the auger rod 7, the upper non-magnetic drill pipe 6, the probe battery barrel 5, the lower non-magnetic drill pipe 4 and the air screw motor 3, and then enters the quantitative air foam dust removal device 2, a small amount of quantitative air is distributed to the annular space gap to generate foam, and the remaining air is discharged through the drill bit 1 for carrying slag;

[0081] Fourth step: the foam liquid pump 17 is turned on to inject foam liquid, the foam liquid passes through the second flow meter 16, the foam liquid pipe 15, the water channel 8, the auger rod 7, the upper non-magnetic drill pipe 6, the probe battery barrel 5, the lower non-magnetic drill pipe 4 and the air screw motor 3, and then enters the annular space gap through the annular groove 215, the axial passage 211 and the radial passage 212, the foam liquid is mixed with the inflowing quantitative air to realize gas-liquid mixing along the spiral blade 224, and the gas-liquid mixture passes through the primary foaming device 24 and the secondary foaming device 25 and then flows out from the foam outlet 213.

[0082] Fifth step: the foam realizes continuous dust capturing effect on the dust production point at the bottom of the hole and in the process of the dust-containing airflow returning to the hole from the annular space, thereby reducing the difficulty of hole mouth dust removal.

[0083] Compared with the traditional air drilling process method of hole mouth dust removal, the foam has the advantages of lubrication, good dust capturing and powder discharging effect, small environmental pollution and the like, and has unique superiority in wet, water-sensitive and unstable strata. During air drilling, the quantitative air foam dust removal device can stably and efficiently generate foam under different air volume and air pressure, can combine with fine coal dust to become larger coal dust in the process of the dust-containing airflow returning to the hole from the annular space, thereby playing a continuous dust capturing effect and reducing the difficulty of hole mouth dust removal. With the increase of the hole depth, the mixing of the foam and the coal dust is more sufficient, and the dust capturing effect is better, which is suitable for the development trend of the current air drilling of broken soft coal seam.

[0084] The above detailed description takes the best embodiments as an example in combination with the drawings, and is not used to limit the present application. In the above description, various specific technical features can be combined in any suitable form without contradiction, and the present application will not be described one by one. Any person skilled in the art can take any combination or equivalent replacement of the technical scheme without departing from the scope of the technical scheme, and the simple modification or modification means does not affect the essence of the technical scheme, which still belongs to the protection scope of the technical scheme represented by each embodiment of the present application.

Claims

1. A quantitative air distribution foam dust removal device, characterized in that, include: The first tube (21) and the second tube (22) are fitted together to form an annular space gap, with one end open; At the open end, the first pipe body (21) has an axial channel (211) and a radial channel (212) embedded in its pipe wall, and the radial channel (212) is connected to the annular space gap; at the open end, the second pipe body (22) is provided with a quantitative air distribution structure to limit the quantitative airflow into the annular space gap; A foam outlet (213) communicating with the annular space gap is provided on the wall of the first tube (21) at the non-open end. The quantitative air distribution structure includes: a limiting ring (23) fitted inside the open end of the first pipe body (21); a baffle plate (222) and a spring (223) sequentially fitted onto the open end of the second pipe body (22); the inner diameter of the limiting ring (23) gradually decreases from the open end, and the baffle plate (222) moves back and forth within the annular space of the limiting ring (23); the external threaded connection of the limiting ring (23) is placed at the stepped surface (216), and the interior is a structural surface with a certain curvature; when the air supply volume is small... When the air pressure is low, the compression spring (223) of the baffle plate (222) moves a short distance, and the cross-sectional area of ​​the quantitative air distribution device formed by the baffle plate (222) and the limiting ring (23) is large; when the air supply is large, the air pressure is high, the compression spring (223) of the baffle plate (222) moves a long distance, and the cross-sectional area of ​​the quantitative air distribution device formed by the baffle plate (222) and the limiting ring (23) is small; as the air supply changes, the quantitative air is always delivered to the gas-liquid mixing channel to ensure the stability of the foaming device; A shaft retaining ring (221) is attached to the front end of the wind baffle (222); an axial guide groove (225) is provided on the pipe wall of the second pipe body (22), and the wind baffle (222) is engaged with the axial guide groove (225); the axial guide groove (225) is a notch extending along the axial direction, which limits the movement distance of the wind baffle (222) along the axial direction, and at least ensures the minimum ventilation volume, so as to avoid sealing the ventilation opening; Spiral blades (224) are installed outside the second pipe (22) at the rear end of the quantitative air distribution structure; a primary foamer (24) and a secondary foamer (25) are sequentially installed at the closed end of the annular space gap; the primary foamer (24) and the secondary foamer (25) are wire mesh structures, and the wire mesh aperture of the primary foamer (24) is larger than that of the secondary foamer (25); after passing through the primary foamer (24) and the secondary foamer (25), dense foam is generated.

2. The quantitative air distribution foam dust removal device according to claim 1, characterized in that, An adapter (26) is axially connected to the open end of the first tube (21).

3. An air drilling system, characterized in that, The system consists of a drill bit (1), a quantitative air distribution foam dust removal device (2), an air screw motor (3), a lower non-magnetic drill rod (4), a probe battery cylinder (5), an upper non-magnetic drill rod (6), a spiral drill rod (7), and a water pipe (8), which are connected in sequence. The quantitative air distribution foam dust removal device (2) is the quantitative air distribution foam dust removal device (2) according to any one of claims 1-2; The water supply (8) is connected to the air supply assembly and the foam supply assembly respectively.

4. The air drilling system according to claim 3, characterized in that, The air supply assembly includes a high-pressure hose (10), a first flow meter (11), a compressed air pipeline (13), and an air compressor (14).

5. The air drilling system according to claim 3, characterized in that, The foam assembly is equipped with a foam liquid pipeline (15), a second flow meter (16), and a foam liquid pump (17).

6. An air drilling process, characterized in that, Implemented using the air drilling system according to any one of claims 3-5, comprising: Step 1: Connect the drill bit (1), quantitative air distribution foam dust removal device (2), air screw motor (3), lower non-magnetic drill rod (4), probe battery cylinder (5), upper non-magnetic drill rod (6) and spiral drill rod (7) in sequence. Step 2: Connect the connected spiral drill rod (7) to the air compressor (14) through the air inlet of the water pipe (8), the high-pressure hose (10), and the compressed air pipeline (13). A pressure relief valve (9) is installed at the end of the water pipe (8). A first flow meter (11) and a shut-off valve (12) are installed between the high-pressure hose (10) and the compressed air pipeline (13). At the same time, the foam liquid inlet of the water pipe (8) is connected to the foam liquid pump (17) through the foam liquid pipeline (15). A second flow meter (16) is installed between the foam liquid pipeline (15) and the foam liquid pump (17). Step 3: Turn on the air compressor (14) to supply air. After the compressed air passes through the compressed air pipeline (13), the shut-off valve (12), the first flow meter (11), the high-pressure hose (10), the water pipe (8), the spiral drill rod (7), the upper non-magnetic drill rod (6), the probe battery cylinder (5), the lower non-magnetic drill rod (4) and the air screw motor (3), a small portion of the quantitative air is distributed to the annular space gap in the quantitative air distribution foam dust removal device (2) to generate foam, and the remaining air is discharged through the drill bit (1) to carry slag. Step 4: Turn on the foam liquid pump (17) to inject foam liquid. After passing through the second flow meter (16), foam liquid pipeline (15), water pipe (8), spiral drill rod (7), upper non-magnetic drill rod (6), probe battery cylinder (5), lower non-magnetic drill rod (4) and air screw motor (3), the foam liquid enters the annular space gap through the annular groove (215), axial channel (211) and radial channel (212). The foam liquid mixes with the incoming quantitative air and achieves gas-liquid mixing along the spiral blades (224). The gas-liquid mixture then passes through the first-stage foamer (24) and the second-stage foamer (25) and flows out from the foam outlet (213).

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