Spraying hole locking type blowout preventer for coal mine gas control

Abstract

The invention discloses a spraying hole locking type blowout preventer for coal mine gas control, which comprises a sleeve, a plurality of locking pieces, a plurality of locking pieces and a plurality of locking pieces, the sleeve is used for sleeving outside a drill hole, the inner wall of the sleeve is circumferentially and rotatably provided with a plurality of locking pieces, and the back of each locking piece is provided with a sliding chute; the multiple wedge blocks are circumferentially distributed on the outer wall of the sleeve and can slide in the radial direction of the sleeve, and the outer side faces of the wedge blocks are inclined faces; the inner side face of each wedge block is fixedly connected with the corresponding push rod, the push rods penetrate through the side wall of the sleeve in a sliding mode, and the ends, located in the sleeve, of the push rods are connected to the sliding grooves in the back faces of the corresponding locking pieces in a sliding mode; and the sliding ring is slidably arranged on the outer wall of the sleeve above the wedge block in a sleeving mode, and the inner wall of the sliding ring is attached to the outer side face of the wedge block. Compared with the prior art, the device has the beneficial effects of double locking, pressure feedback, capability of still keeping sealing after the drill rod is withdrawn and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of gas control, and particularly to a spray hole locking type anti-blowout device for coal mine gas control. Background Art

[0002] During the coal mining process, gas, as the main harmful gas underground, its control work is crucial. Especially in the drilling operation, due to complex geological conditions, large differences in coal seam permeability and other factors, the phenomenon of gas spray holes often occurs. Gas spray holes will not only deteriorate the working environment at the operation site, increase safety hazards, but may also trigger catastrophic accidents such as gas explosions in severe cases.

[0003] Currently, in response to the problem of coal mine gas spray holes, there are already various anti-blowout devices on the market. The hydraulic anti-blowout device uses the hydraulic principle to achieve the locking function. Its structure includes a hydraulic pump, a hydraulic cylinder, a locking mechanism, etc. When a gas spray hole occurs, the hydraulic pump starts, pushes the piston of the hydraulic cylinder to move, and then drives the locking mechanism to act. Although this type of device has a large locking force, it also requires an external power source, and the complexity of the hydraulic system and the maintenance cost are relatively high. The locking mechanism is triggered by the change in air pressure. Its structure includes components such as an air pressure sensor, a control valve, and a locking piece. When the air pressure in the drill hole suddenly rises, the air pressure sensor will send a signal, the control valve opens, and the locking piece acts. However, this type of device has a high sensitivity requirement for air pressure changes, and there is a risk of leakage between the locking structures.

[0004] Although the anti-blowout devices of the prior art have alleviated the problem of gas spray holes to a certain extent, there are still some deficiencies: Whether it is a hydraulic or pneumatic anti-blowout device, an external power source is required to drive it to achieve the locking function. This results in a relatively slow response speed of the device, and it may not work properly due to power source failure in an emergency. In the locking process of the anti-blowout devices of the prior art, there are often tiny gaps between the locking structures. Although these gaps seem insignificant, under the action of high-pressure gas, they may become channels for gas leakage, thus affecting the anti-blowout effect. After the drill pipe exits the drill hole, at this time, although the locking structure of the anti-blowout device can seal the gap between the drill hole and the drill pipe, the central hole often cannot be sealed in time. If the central hole remains open for a long time, gas may leak out from these holes, causing safety hazards.

[0005] Therefore, it is necessary to provide a spray hole locking type anti-blowout device for coal mine gas control to solve the problems raised in the above background art. Summary of the Invention

[0006] To achieve the above object, the present invention provides the following technical solution: A spray hole locking type anti-blowout device for coal mine gas control, comprising:

[0007] A casing, the casing is used to sleeve outside a drill hole, and a plurality of locking pieces are circumferentially and rotatably arranged on the inner wall thereof, and a chute is arranged on the back surface of the locking piece;

[0008] Wedges, a plurality of the wedges are circumferentially distributed on the outer wall of the casing and can slide along the radial direction of the casing, and the outer side surface of the wedge is an inclined surface;

[0009] Push rods, each inner side surface of the wedges is fixedly connected with a push rod, the push rod slidably penetrates through the side wall of the casing, and one end of the push rod located inside the casing is slidably connected to the chute on the back surface of the corresponding locking piece;

[0010] A sliding ring, which is slidably sleeved on the outer wall of the casing above the wedge, and the inner wall of the sliding ring fits with the outer side surface of the wedge.

[0011] Further, two circles of locking pieces are distributed up and down inside the casing, the upper circle of locking pieces can rotate upward from the horizontal direction, the lower circle of locking pieces can rotate downward from the horizontal direction, and the gaps between adjacent two locking pieces in the same circle of the upper and lower two circles of locking pieces are staggered from each other.

[0012] Further, on both sides of the casing below the wedge, there are respectively arranged horizontal side pipes, the side pipes are communicated with the casing, pistons are slidably arranged inside the side pipes, sliding rods are connected in the pistons, the end of the sliding rod is hinged with a connecting rod, and the other end of the connecting rod is hinged to the sliding ring.

[0013] Further, a piston spring is arranged between each piston and the inner wall of the casing.

[0014] Further, a plurality of downwardly inclined positioning pins are slidably arranged in the side wall of the casing, and each positioning pin abuts against the corresponding wedge;

[0015] The lower end of the positioning pin penetrates into the casing, a retaining ring is slidably arranged on the inner wall of the casing, and the retaining ring blocks the lower end of the positioning pin.

[0016] Further, a plurality of vertical connecting rods are fixed in the retaining ring, and a retaining piece is fixed at the end of each of the connecting rods.

[0017] Further, a plurality of elastic pieces are arranged between the retaining ring and the inner wall of the casing, and in the natural state, the elastic pieces enable the retaining ring to be at the position where the end of the positioning pin is located.

[0018] Further, a groove is formed in each locking piece, a triangular sliding piece is slidably arranged in the groove, and when each sliding piece in the same circle of locking pieces slides to the position closest to the axis, the adjacent sliding pieces are mutually attached.

[0019] Further, a sliding piece spring is arranged between each sliding piece and the corresponding locking piece, and the sliding piece spring provides an elastic force for enabling the sliding piece to slide towards the direction close to the axis.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] In the present invention, when a blowhole phenomenon occurs during drilling operation, when a blowhole occurs in the drill hole, the air pressure will first act on the baffle, causing the slip ring to slide downward along the axial direction of the casing. The inclined surface of the wedge block forces all the wedge blocks to move synchronously towards the axis of the casing, driving the push rod to push the locking piece to rotate around the rotating shaft to a horizontal state, thereby closing the annular gap between the inner wall of the casing and the drill pipe. This process is completed immediately when the blowhole phenomenon occurs, effectively preventing the leakage of gas.

[0022] In the present invention, two circles of locking pieces are distributed up and down in the device, and the gaps between adjacent locking pieces are staggered from each other, which not only enhances the stability of locking, but also avoids the leakage of gas from the gaps between adjacent locking pieces, further improving the sealing effect.

[0023] In the present invention, the piston and connecting rod structure in the device enables the locking to have a feedback effect. When the inside of the casing is in a high-pressure state, the piston will slide to the side away from the axis of the casing, thereby causing the connecting rod to pull the slip ring downward, and then pushing the wedge block to make the locking piece in a horizontal state. The locking force of the locking piece increases with the increase of the pressure inside the casing, effectively preventing the locking piece from being blown open by the air pressure.

[0024] In the present invention, after the drill rod is withdrawn, the sliding piece can slide towards the axis direction under the action of the sliding piece spring, thereby sealing the central hole surrounded by the sliding pieces, ensuring that even after the drill rod is withdrawn, the device can still maintain a sealed state and prevent the leakage of gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a blowhole locking type blowout prevention device for coal mine gas control;

[0026] Figure 2 It is a schematic semi-sectional structure diagram inside the casing;

[0027] Figure 3 It is a schematic sectional structure diagram inside the casing;

[0028] Figure 4 It is a schematic structural diagram at the positioning pin;

[0029] Figure 5 It is a schematic structural diagram of the locking piece when the sliding piece contracts;

[0030] Figure 6 It is a schematic structural diagram of the locking piece when the sliding piece extends;

[0031] In the figure: 1. Sleeve; 2. Locking piece; 21. Groove; 22. Slide piece; 23. Slide piece spring; 3. Wedge block; 4. Push rod; 5. Slip ring; 6. Side pipe; 7. Piston; 8. Slide rod; 9. Connecting rod; 10. Piston spring; 11. Stop ring; 12. Positioning pin; 13. Connecting rod; 14. Retaining piece; 15. Elastic piece.. Specific implementation mode

[0032] Please refer to Figures 1 - 5 , in the embodiment of the present invention, a spray hole locking type anti-spray device for coal mine gas control includes:

[0033] A sleeve 1, the sleeve 1 is used to sleeve the outside of the drill hole, and a plurality of locking pieces 2 are circumferentially and rotatably arranged on the inner wall thereof, and a chute is arranged on the back surface of the locking piece 2;

[0034] Wedge blocks 3, a plurality of the wedge blocks 3 are circumferentially distributed on the outer wall of the sleeve 1 and can slide along the radial direction of the sleeve 1, and the outer side surface of the wedge block 3 is an inclined surface;

[0035] A push rod 4, the inner side surface of each wedge block 3 is fixedly connected with a push rod 4, the push rod 4 slidably penetrates through the side wall of the sleeve 1, and one end of the push rod 4 located inside the sleeve 1 is slidably connected to the chute on the back surface of the corresponding locking piece 2;

[0036] A slip ring 5 is slidably sleeved on the outer wall of the sleeve 1 above the wedge block 3, and the inner wall of the slip ring 5 is attached to the outer side surface of the wedge block 3.

[0037] That is to say, when the drill pipe is in the sleeve 1 for drilling operation, once the spray hole phenomenon occurs, the slip ring 5 slides downward along the axial direction of the sleeve 1, and all the wedge blocks 3 are forced to move synchronously towards the axis direction of the sleeve 1 through the inclined surface of the wedge block 3, driving the push rod 4 to push the locking piece 2 to rotate to the horizontal state around the rotation axis, closing the annular gap between the inner wall of the sleeve 1 and the drill pipe.

[0038] In this embodiment, two circles of locking pieces 2 are distributed up and down in the sleeve 1. The upper circle of locking pieces 2 can rotate upward from the horizontal direction, and the lower circle of locking pieces 2 can rotate downward from the horizontal direction, and the gaps between adjacent two locking pieces 2 in the same circle of the upper and lower two circles of locking pieces 2 are staggered from each other.

[0039] That is to say, when the two circles of locking pieces 2 are in the horizontal state, the gaps between adjacent locking pieces 2 can be sealed, and gas leakage from the gaps between adjacent locking pieces 2 can be avoided.

[0040] In this embodiment, on both sides of the sleeve 1 below the wedge block 3, a horizontal side pipe 6 is provided respectively. The side pipe 6 is communicated with the sleeve 1. A piston 7 is slidably arranged in the side pipe 6. A slide rod 8 is connected in the piston 7. The end of the slide rod 8 is hinged with a connecting rod 9, and the other end of the connecting rod 9 is hinged to the slip ring 5.

[0041] That is to say, when the inside of the casing 1 is in a high-pressure state, the piston 7 will slide to the side away from the axis of the casing 1, so that the connecting rod 9 pulls the slip ring 5 to slide downward, and then pushes the wedge block 3 to make the locking piece 2 in a horizontal state, so that the locking has a feedback effect. The greater the pressure inside the casing 1, the greater the locking force of the locking piece 2, which can prevent the locking piece 2 from being blown open by the air pressure.

[0042] In this embodiment, a piston spring 10 is arranged between each piston 7 and the inner wall of the casing 1.

[0043] In this embodiment, a plurality of downwardly inclined positioning pins 12 are slidably arranged in the side wall of the casing 1, and each positioning pin 12 abuts against the corresponding wedge block 3;

[0044] The lower end of the positioning pin 12 penetrates into the casing 1, and a retaining ring 11 is slidably arranged on the inner wall of the casing 1, and the retaining ring 11 blocks the lower end of the positioning pin 12.

[0045] In this embodiment, a plurality of vertical connecting rods 13 are fixed in the retaining ring 11, and a retaining piece 14 is fixed at the end of each connecting rod.

[0046] In this embodiment, a plurality of elastic pieces 15 are arranged between the retaining ring 11 and the inner wall of the casing 1, and the elastic pieces 15 make the retaining ring 11 in the position where the end of the positioning pin 12 is located in the natural state.

[0047] That is to say, when a blowout occurs in the borehole, the air pressure will first act on the retaining piece 14, thereby pushing the retaining ring 11 to move upward against the elastic force of the elastic piece 15. When the retaining ring 11 moves upward to leave the lower end of the positioning pin 12, the positioning pin 12 will not be able to abut against the corresponding wedge block 3, so that the piston 7 is pushed to slide to the side away from the axis of the casing 1 under the action of the piston spring 10, making the locking piece 2 in a horizontal state to lock the locking piece 2 in advance before the gas arrives.

[0048] In this embodiment, a groove 21 is formed in each locking piece 2, a triangular sliding piece 22 is slidably arranged in the groove 21, and when each sliding piece 22 in the same circle of locking pieces 2 slides to the closest position to the axis, the adjacent sliding pieces 22 are in contact with each other;

[0049] A sliding piece spring 23 is arranged between each sliding piece 22 and the corresponding locking piece 2, and the sliding piece spring 23 provides an elastic force for the sliding piece 22 to slide in the direction close to the axis.

[0050] That is to say, when there is a drill pipe at the center of the locking piece 2, when the locking piece 2 rotates horizontally, the sliding piece 22 will be blocked by the drill pipe and retracted into the groove 21. Once the drill pipe is retracted, the sliding piece 22 loses the block and will slide towards the axis direction under the action of the sliding piece spring 23, so as to seal the central hole surrounded by the sliding piece 22, ensuring that the sealed state can still be maintained after the drill pipe is retracted.

[0051] During specific implementation, it includes:

[0052] Device installation: Drilling and fixing. Fix the casing 1 to the orifice of the drilling hole through the flange, ensuring that the flange sealing groove is closely attached to the orifice sealing surface. Fasten the flange with bolts and check that the axis of the casing 1 is aligned with the axis of the drilling hole. Insert the drill pipe into the casing 1 from the top of the casing 1, ensuring that the drill pipe is located at the center of the casing. The locking piece 2 is in the initial state (tilted state) to avoid hindering the movement of the drill pipe.

[0053] Automatic triggering of the locking for sudden jet holes: High-pressure gas acts on the baffle 14, pushing the retaining ring 11 to slide upward against the elastic force of the elastic piece 15. The retaining ring 11 disengages from the lower end of the positioning pin 12, releasing the locking of the positioning pin 12. The piston spring 10 pushes the piston 7 in the side pipe 6 to slide outward. The connecting rod 9 pulls the sliding ring 5 to move downward, and its inner wall slides along the inclined surface of the wedge block 3, forcing all the wedge blocks 3 to move synchronously towards the axis of the casing. The push rod 4 pushes the locking piece 2 to rotate around the axis to the horizontal state. The upper and lower two circles of locking pieces 2 are staggered and closed to seal the gap between the drill pipe and the casing. The adjacent locking pieces 2 are misaligned and sealed to eliminate gap leakage. The sliding piece 22 is blocked by the drill pipe and retracted into the groove 21.

[0054] Retracting the drill pipe: When it is necessary to stop the drilling operation due to continuous high pressure of gas, the drill pipe needs to be retracted. Slowly retract it until it is completely withdrawn from the casing 1. After the drill pipe is withdrawn, the sliding piece 22 loses the block and slides towards the axis under the action of the sliding piece spring 23. The sliding pieces 22 of the locking pieces 2 in the same circle fit together to form a triangular sealing ring, completely sealing the central hole.

[0055] The above-mentioned is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, makes equivalent substitutions or changes, and should be covered within the protection scope of the present invention.

Claims

1. A nozzle-locking type blowout prevention device for coal mine gas control, characterized in that: include: A sleeve (1), the sleeve (1) being used for being sleeved on the outside of a drill hole, and having an inner wall thereof provided with a plurality of locking plates (2) for circumferential rotation, and a slide groove being provided on the back of the locking plates (2); A wedge block (3), wherein a plurality of the wedge blocks (3) are circumferentially distributed on the outer wall of the sleeve (1) and can slide radially along the sleeve (1), and the outer side surface of the wedge block (3) is an inclined surface; A push rod (4), the inner side surface of each wedge block (3) is fixedly connected to a push rod (4), the push rod (4) slides through the side wall of the sleeve (1), and one end of the push rod (4) located in the sleeve (1) is slidably connected to a slide groove on the back side of the corresponding locking plate (2); A slip ring (5) is slidably sleeved on the outer wall of the sleeve (1) above the wedge block (3), and the inner wall of the slip ring (5) is in contact with the outer side surface of the wedge block (3).

2. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 1 is characterized in that: Two circles of locking plates (2) are arranged in the upper and lower parts of the sleeve (1); the upper circle of locking plates (2) can be rotated upward from the horizontal direction, and the lower circle of locking plates (2) can be rotated downward from the horizontal direction; and the gaps between two adjacent locking plates (2) in the same circle of the upper and lower circles of locking plates (2) are staggered.

3. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 1 is characterized in that: A transverse side tube (6) is provided on both sides of the sleeve (1) below the wedge block (3). The side tube (6) is connected to the sleeve (1). A piston (7) is slidably provided in the side tube (6). A sliding rod (8) is connected to the piston (7). A connecting rod (9) is hinged at the end of the sliding rod (8). The other end of the connecting rod (9) is hinged to the slip ring (5).

4. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 3 is characterized in that: A piston spring (10) is arranged between each piston (7) and the inner wall of the sleeve (1).

5. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 3 is characterized in that: A plurality of downwardly inclined positioning pins (12) are slidably disposed in the side wall of the sleeve (1), and each positioning pin (12) abuts against a corresponding wedge block (3); The lower end of the positioning pin (12) penetrates into the sleeve (1), and a retaining ring (11) is slidably provided on the inner wall of the sleeve (1), and the retaining ring (11) retains the lower end of the positioning pin (12).

6. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 5 is characterized in that: A plurality of vertical connecting rods (13) are fixed in the baffle ring (11), and a baffle (14) is fixed at the end of each of the connecting rods.

7. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 5 is characterized in that: A plurality of spring sheets (15) are arranged between the retaining ring (11) and the inner wall of the sleeve (1), and the spring sheets (15) enable the retaining ring (11) to be located at the position where the end of the positioning pin (12) is located in a natural state.

8. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 2 is characterized in that: Each locking plate (2) is provided with a groove (21), in which a triangular sliding plate (22) is slidably arranged, and when each sliding plate (22) in the same circle of locking plates (2) slides to the position closest to the axis, adjacent sliding plates (22) fit together.

9. The nozzle-locking type blowout prevention device for coal mine gas control according to claim 8, characterized in that: A sliding plate spring (23) is provided between each sliding plate (22) and the corresponding locking plate (2), and the sliding plate spring (23) provides an elastic force for causing the sliding plate (22) to slide in a direction close to the axis.

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