Intermittent grouting fire preventing and extinguishing device and method for coal mine goaf

Abstract

The invention relates to an intermittent grouting fire preventing and extinguishing device and method for a coal mine goaf, and belongs to the technical field of coal mine fire preventing and extinguishing. The tube distributor is arranged on the arch-shaped bracket and is used for distributing the fire extinguishing agent; the main pipeline is used for conveying a fire extinguishing agent and is communicated with the branch pipe device; one end of the grouting rod is communicated with the branch pipe device, and the other end of the grouting rod penetrates through the top of the arch-shaped support to penetrate into the goaf top plate and is used for injecting a fire extinguishing agent into the top plate for preventive grouting; and the spraying assembly is connected below the pipe distributing device and used for spraying a fire extinguishing agent into the goaf space. The invention has the advantages of preventive grouting function, flexible fire fighting capability and efficient fire extinguishing agent utilization effect.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine fire prevention and extinguishing, and in particular relates to an intermittent grouting fire prevention and extinguishing device and method for coal mine goaf areas. Background Art

[0002] In the process of coal mining, the safety management of goaf has always been an important challenge faced by coal mining enterprises. Due to the complexity of coal seam geological conditions and the disturbance of coal mining activities to coal seams, goafs often form cracks connected to the surface or adjacent coal seams. These cracks may not only become air leakage channels, aggravating the oxidation and spontaneous combustion process of coal seams, but also become channels for the spread of fire, seriously threatening the safe production of coal mines.

[0003] Grouting fire prevention devices mainly inject fire extinguishing materials (such as water, yellow mud, fly ash, etc.) into the roof of the goaf or the inside of the coal wall to block the air leakage channel and slow down the oxidation and spontaneous combustion rate of the coal seam. The grouting pump pressurizes the fire extinguishing material and injects it into the grouting hole through the grouting pipe, and then penetrates into the cracks of the coal seam and the roof. The fire extinguishing agent spraying device is mainly used for rapid fire extinguishing after the fire occurs. These devices spray water, foam, dry powder and other fire extinguishing agents to quickly reduce the temperature of the fire source, isolate oxygen, and achieve the purpose of fire extinguishing. When a fire occurs, the control system starts the sprinkler head to spray the fire extinguishing agent into the fire source area.

[0004] The current grouting fire prevention device mainly blocks the potential fire sources in the cracks of the coal seam and roof, but its fire extinguishing effect is limited for the surface fire sources that have already formed. This is mainly reflected in the limited coverage of the fire extinguishing device, which is difficult to cover all fire sources. If the fire extinguishing agent fails to fully penetrate into the cracks of the coal seam and roof, or fails to form an effective covering layer to isolate oxygen, the fire is easy to reignite after the fire is extinguished. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an intermittent grouting fire prevention and extinguishing device and method for coal mine goaf, which has a preventive grouting function, flexible fire fighting capability, and efficient fire extinguishing agent utilization effect.

[0006] An intermittent grouting fire prevention and extinguishing device for coal mine goaf, comprising a plurality of arch supports, which are sequentially attached to the inner wall of the goaf tunnel of the coal mine to provide support;

[0007] A distributor, which is arranged on an arch support and is used for distributing the fire extinguishing agent;

[0008] A main pipeline, used for conveying fire extinguishing agent, and connected with the branch pipe;

[0009] A grouting rod, one end of which is connected to the manifold, and the other end of which passes through the top of the arch support and penetrates into the roof of the goaf, and is used to inject fire extinguishing agent into the roof for preventive grouting;

[0010] The spraying assembly is connected below the distributor and is used to spray the fire extinguishing agent into the goaf space.

[0011] A plurality of fire extinguishing agent outlets are arranged on the top of the manifold, and the fire extinguishing agent outlets are used to connect one end of the grouting rod.

[0012] The spray assembly includes a cylindrical shell with multiple openings distributed on the side wall of the shell; a centrifugal wheel is rotatably connected inside the shell, the middle part of the centrifugal wheel is connected to the distributor, and the fire extinguishing agent enters the middle part of the centrifugal wheel from the distributor and enters the shell through the side of the centrifugal wheel; a driving motor is fixed under the shell.

[0013] A guide plate is rotatably arranged in each of the openings, and a rotating shaft is connected to one side of the guide plate. The rotating shaft is rotatably connected to the upper and lower surfaces of the shell, thereby forming a gap at the opening of the shell side wall; the size of the gap in the opening of the shell side wall is changed by rotating the angle of the guide plate, thereby adjusting the flow and range of spraying the fire extinguishing agent.

[0014] The lower end of the rotating shaft of the guide plate passes through the outside of the shell, and a rotating rod arranged vertically therewith is fixed to the lower end of the rotating shaft; a lift plate that can be raised and lowered is provided under the shell, and a plurality of universal rods are distributed on the lifting plate along its circumference, one end of the universal rod is connected to the lifting plate, and the other end of the universal rod is connected to each of the rotating rods; the lifting plate is driven by a lifting cylinder, and the lifting cylinder drives the lifting plate to rise and fall along the axial direction of the shell, so that each universal rod synchronously pushes the corresponding rotating rod to rotate, thereby adjusting the rotation angle of each guide plate.

[0015] A stirring assembly is rotatably arranged between each two adjacent guide plates in the shell.

[0016] A gear is fixed above the stirring component, a gear ring is fixed above the centrifugal wheel, and the gear ring is meshed with each of the gears.

[0017] The stirring assembly includes an upper shaft, which is coaxially fixed with the gear, and a lower shaft is slidably connected below the upper shaft; a plurality of upper stirring rods are hinged circumferentially around the upper shaft, and a plurality of lower stirring rods are hinged circumferentially around the lower shaft, and the upper stirring rods and the lower stirring rods are hinged to each other; the angle between the upper stirring rod and the lower stirring rod, that is, the opening amplitude, is changed by raising and lowering the axial sliding of the lower shaft.

[0018] The lower end of the lower shaft is rotatably connected to a connection cover, a lifting shaft is fixed below the connection cover, the lifting shaft slides through the bottom plate of the shell and is fixedly connected to the lifting plate, and the lifting shaft moves up and down driven by the lifting plate.

[0019] The method for using the intermittent grouting fire prevention and extinguishing device for coal mine goafs specifically comprises the following steps:

[0020] S1. Device installation:

[0021] S1-1, attach multiple arch supports to the inner wall of the tunnel in the coal mine goaf in sequence to ensure that the supports are stable and provide support;

[0022] S1-2. Fix the manifold in the arch bracket and install the main pipeline so that the manifold is connected to the main pipeline to ensure that the fire extinguishing agent can be evenly distributed;

[0023] S1-3. Install multiple grouting rods on the top of each bracket to ensure that the grouting rods can penetrate into the roof of the goaf;

[0024] S1-4. Fix the spraying assembly under each manifold to ensure that the spraying assembly can accurately spray the fire extinguishing agent into the goaf space;

[0025] S2. Preventive grouting:

[0026] S2-1. Adjust the grouting pressure and flow rate of the grouting rod according to the tunnel conditions and crack conditions;

[0027] S2-2, inject fire extinguishing agent into the top plate through the grouting rod to carry out preventive grouting to block the air leakage channel;

[0028] S2-3. Observe the grouting effect and adjust the grouting pressure and flow rate according to actual needs to ensure that the fire extinguishing agent fully fills the cracks;

[0029] S3. Fire fighting:

[0030] S3-1. When a fire occurs, immediately start the drive motor of the spray assembly to drive the centrifugal wheel to rotate;

[0031] S3-2, the lifting plate is driven to lift and slide by the lifting cylinder, and the opening gap size of the spraying component is changed by adjusting the rotation angle of the guide plate, thereby adjusting the flow rate and range of the spraying fire extinguishing agent;

[0032] S3-3. Stirring the fire extinguishing agent: When the centrifugal wheel rotates, it drives the stirring assembly to rotate in the opposite direction, stirring the fire extinguishing agent sprayed from the opening of the side wall of the spray assembly to increase its foaming degree.

[0033] By means of the above technical solution, the present invention has at least the following beneficial effects:

[0034] The present invention uses multiple arched supports to fit the inner wall of the tunnel in the coal mine goaf to form a stable support structure. The fire extinguishing agent is evenly distributed to each grouting rod through the main pipeline and the distributor. The grouting rod can intermittently inject the fire extinguishing agent into the roof, effectively blocking the air leakage channel and preventing the coal seam from spontaneously igniting. It not only reduces the risk of spontaneous combustion of the coal seam, but also promotes the formation of the regenerated roof, further enhancing the stability of the tunnel.

[0035] When a fire occurs, the spray assembly can be quickly activated, and the centrifugal wheel is driven by the drive motor to rotate, so that the fire extinguishing agent is centrifugally diffused to the surroundings and sprayed out from the opening to achieve rapid fire extinguishing. The design of the spray assembly allows the flow and range of the fire extinguishing agent to be adjusted according to the fire intensity. By changing the rotation angle of the guide plate, the spraying range and the distribution of the fire extinguishing agent can be accurately controlled to improve the fire extinguishing efficiency.

[0036] The stirring assembly in the spraying assembly can rotate in the opposite direction when the centrifugal wheel rotates, stirring the fire extinguishing agent sprayed from the opening to increase its foaming degree. The foamed fire extinguishing agent can quickly form a covering layer, isolate oxygen, and inhibit the oxidation and spontaneous combustion process of coal. At the same time, the foam layer can remain moist for a long time, continuously absorb heat and cool down, effectively prevent the fire area from re-igniting, and improve the utilization efficiency of the fire extinguishing agent. The device drives the lifting plate to lift and slide through the lifting cylinder, automatically adjusts the rotation angle of the guide plate and the opening range of the stirring assembly, and realizes accurate spraying and efficient stirring of the fire extinguishing agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A schematic diagram of the structure of an intermittent grouting fire prevention and extinguishing device for coal mine goaf provided by the present invention;

[0038] Figure 2 It is a schematic diagram of the overall structure of the spray assembly in the present invention;

[0039] Figure 3 is a schematic diagram of a longitudinal section of a spray assembly in the present invention;

[0040] Figure 4 is a schematic diagram of a transverse cross-section of a spray assembly in the present invention;

[0041] Figure 5 It is a structural schematic diagram of the stirring assembly in the present invention;

[0042] in:

[0043] 1- bracket, 2- main pipeline, 3- distributor, 4- grouting rod, 5- spraying assembly, 51- shell, 52- guide plate, 53- centrifugal wheel, 54- rotating rod, 55- universal rod, 56- stirring assembly, 561- upper shaft, 562- lower shaft, 563- upper stirring rod, 564- lower stirring rod, 565- connecting cover, 57- gear ring, 58- gear, 59- lifting shaft, 6- driving motor, 7- lifting plate, 8- lifting cylinder. DETAILED DESCRIPTION

[0044] In order to better explain the present invention and facilitate understanding, the technical solutions and effects of the present invention are described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0045] An intermittent grouting fire prevention and extinguishing device for coal mine goaf, such as Figure 1-5 As shown, it includes a plurality of arch supports 1, which are sequentially attached to the inner wall of the tunnel in the goaf of the coal mine and arranged along the direction of the tunnel to provide support. A manifold 3 is provided on the arch support 1, and the main pipeline 2 is connected to the manifold 3 and fixedly installed in the arch support 1 for conveying fire extinguishing agent. A plurality of fire extinguishing agent outlets are provided above the manifold 3, and the plurality of fire extinguishing agent outlets are connected to the grouting rod 4, and the end of the grouting rod 4 passes through the top of the arch support 1 and penetrates into the roof of the goaf. The manifold 3 is used to evenly distribute the fire extinguishing agent conveyed by the main pipeline 2, and intermittently inject the fire extinguishing agent into the roof through the grouting rod to block the air leakage channel and promote the formation of a regenerated roof.

[0046] Due to the existence of faults, folds and other factors in coal seam geology, as well as the impact of coal mining and tunneling on coal seams, cracks connected to the goaf may be formed, and these cracks may become air leakage channels. According to the conditions of the tunnel, the arch support 1 is arranged in the crack high-incidence area, the grouting pressure and flow of the grouting rod 4 are adjusted, and the fire extinguishing agent is injected into the roof for preventive grouting to block the air leakage channel and form a regenerated roof to ensure that it effectively isolates the wind flow and prevents the fire from spreading to other areas.

[0047] The manifold distributor 3 is connected with a spraying assembly 5 which is fixed below the manifold distributor 3 and is used to spray the fire extinguishing agent distributed from the main pipeline 2 by the manifold distributor 3 into the goaf space to achieve rapid fire extinguishing.

[0048] Specifically, when a fire occurs, the spraying assembly 5 is activated to spray the fire extinguishing agent into the goaf space to quickly extinguish the fire source.

[0049] As a preference, Figure 2 As shown, the spray assembly 5 includes a cylindrical shell 51, and a plurality of openings are distributed on the side wall of the shell 51. A centrifugal wheel 53 is rotatably connected in the shell 51, and the middle part of the centrifugal wheel 53 is connected with the manifold distributor 3. The fire extinguishing agent enters the middle part of the centrifugal wheel 53 from the manifold distributor 3, and enters the shell 51 through the side of the centrifugal wheel 53. A driving motor 6 is fixed below the shell 51, and the centrifugal wheel 53 is connected to the output end of the driving motor 6. The driving motor 6 drives the centrifugal wheel 53 to rotate, so that the fire extinguishing agent entering the shell 51 from the manifold distributor 3 is spread to the surroundings by centrifugal action and sprayed out from the openings on the side wall of the shell 51.

[0050] A guide plate 52 is rotatably arranged in each of the openings, and a rotating shaft is connected to one side of the guide plate 52, and the rotating shaft is rotatably connected to the upper and lower surfaces of the shell 51, so as to form a gap at the opening of the side wall of the shell 51. The gap size of the opening of the side wall of the shell 51 is changed by rotating the angle of the guide plate 52, so as to adjust the flow rate and range of the sprayed fire extinguishing agent to adapt to different fire conditions. When there are multiple scattered fire sources in the goaf, the gap size of the opening of the shell 51 can be reduced to increase the spraying range to ensure that the fire extinguishing agent can cover all fire sources and achieve comprehensive fire extinguishing; for concentrated fire sources, the gap size of the opening of the shell 51 can be increased to reduce and concentrate the spraying range, so as to improve the utilization rate of the fire extinguishing agent and the fire extinguishing efficiency.

[0051] By rotating the guide plate 52, the size of the gap of the opening of the shell 51 can be changed, thereby adjusting the flow rate and range of the fire extinguishing agent sprayed to adapt to different fires. When there are multiple dispersed fire sources in the goaf, the size of the gap of the opening of the shell 51 can be reduced to increase the spraying range to ensure that the fire extinguishing agent can cover all fire sources and achieve comprehensive fire extinguishing; for concentrated fire sources, the size of the gap of the opening of the shell 51 can be increased to reduce and concentrate the spraying range to improve the utilization rate of the fire extinguishing agent and the fire extinguishing efficiency.

[0052] In this embodiment, the lower end of the rotating shaft of the guide plate 52 passes through the outside of the housing 51, and a rotating rod 54 arranged vertically therewith is fixed to the lower end of the rotating shaft. A lifting plate 7 that can be raised and lowered is arranged below the housing 51, and a plurality of universal rods 55 are distributed on the lifting plate 7 along its circumference, one end of the universal rod 55 is connected to the lifting plate 7, and the other end of the universal rod 55 is connected to each of the rotating rods 54. The lifting plate 7 is driven by a lifting cylinder 8, and the fixed end of the lifting cylinder 8 is fixed to a fixed frame on the driving motor 6.

[0053] By driving the lifting plate 7 to move up and down along the axial direction of the housing 51 through the lifting cylinder 8 , each universal rod 55 can synchronously push its corresponding rotating rod 54 to rotate, thereby adjusting the rotation angle of each guide plate 52 .

[0054] Preferably, a stirring assembly 56 is rotatably provided between each two adjacent guide plates 52 in the housing 51. The fire extinguishing agent sprayed from the opening of the side wall of the housing 51 is stirred by the stirring assembly 56 to increase its foaming degree. The foamed fire extinguishing agent can quickly form a thick foam covering layer in the coal mine fire area, effectively isolating oxygen, thereby inhibiting the oxidation and spontaneous combustion process of coal, and achieving the purpose of rapid fire extinguishing. At the same time, the foam layer can remain moist for a long time, continuously absorb heat and cool down, and prevent the fire area from re-igniting.

[0055] In this embodiment, a stirring assembly 56 is rotatably disposed between each two adjacent guide plates 52 in the housing 51. A gear 58 is fixed above the stirring assembly 56, and a gear ring 57 is fixed above the centrifugal wheel 53, and the gear ring 57 is meshed with each gear 58. When the centrifugal wheel 53 rotates under the drive of the driving motor 6, it can drive each stirring assembly 56 to rotate in the opposite direction, thereby stirring the fire extinguishing agent to be sprayed out from the opening of the side wall of the housing 51.

[0056] Preferably, the stirring assembly 56 includes an upper shaft 561, which is coaxially fixed with the gear 58, and a lower shaft 562 is slidably connected below the upper shaft 561. A plurality of upper stirring rods 563 are hingedly connected to the circumference of the upper shaft 561, and a plurality of lower stirring rods 564 are hingedly connected to the circumference of the lower shaft 562. The upper stirring rods 563 and the lower stirring rods 564 are hingedly connected to each other. By lifting and lowering the lower shaft 562 to slide along the axial direction of the upper shaft 561, the angle between the upper stirring rods 563 and the lower stirring rods 564, i.e., the opening range, can be changed, thereby adapting to the size of the gap opened by the guide plate 52.

[0057] Furthermore, the lower end of the lower shaft 562 is rotatably connected to a connecting cover 565, and a lifting shaft 59 is fixed below the connecting cover 565. The lifting shaft 59 slides through the bottom plate of the outer shell 51 and is fixedly connected to the lifting plate 7. The lifting shaft 59 can move up and down along its axis under the drive of the lifting plate 7.

[0058] In this embodiment, the lower end of the lower shaft 562 is rotatably connected to a connection cover 565, and a lifting shaft 59 is fixed below the connection cover 565. The lifting shaft 59 passes through the bottom plate of the housing 51 and is fixedly connected to the lifting plate 7. The lifting shaft 59 can move up and down along the circumference of the lifting plate 7. When the lifting plate 7 is lifted or lowered, the opening range of the upper and lower stirring rods is adjusted while adjusting the opening range of the guide plate 52. Specifically, when the lifting plate 7 is lifted or lowered, the lower shaft 562 can be driven by the lifting shaft 59 to move synchronously, thereby changing the opening range of the upper stirring rod 563 and the lower stirring rod 564.

[0059] That is to say, when the lifting plate 7 rises, the open gap of the guide plate 52 becomes larger, and the opening range of the upper stirring rod 563 and the lower stirring rod 564 also becomes larger; conversely, when the lifting plate 7 descends, the open gap of the guide plate 52 becomes smaller, and the opening range of the upper stirring rod 563 and the lower stirring rod 564 also becomes smaller, so that it can automatically adapt to the open gap of the guide plate 52, ensuring that the fire extinguishing agent sprayed from the opening of the side wall of the outer shell 51 can be stirred, and preventing the upper stirring rod 563 and the lower stirring rod 564 from hitting the guide plate 52.

[0060] The method for using the intermittent grouting fire prevention and extinguishing device for coal mine goaf specifically comprises the following steps:

[0061] S1. Device installation:

[0062] S1-1, attaching multiple arch supports 1 to the inner wall of the tunnel in the coal mine goaf in sequence, ensuring that the supports are stable and provide support;

[0063] S1-2, fix the manifold 3 in the arch support 1, and install the main pipeline 2, so that the manifold 3 is connected with the main pipeline 2 to ensure that the fire extinguishing agent can be evenly distributed;

[0064] S1-3, a plurality of grouting rods 4 are fixedly installed on the top of each bracket 1 to ensure that the grouting rods can penetrate into the roof of the goaf;

[0065] S1-4, fix the spraying assembly 5 under each manifold 3 to ensure that the spraying assembly can accurately spray the fire extinguishing agent into the goaf space;

[0066] S2. Preventive grouting:

[0067] S2-1, adjusting the grouting pressure and flow rate of the grouting rod 4 according to the tunnel conditions and crack conditions;

[0068] S2-2, injecting fire extinguishing agent into the top plate through the grouting rod 4 to perform preventive grouting to block the air leakage channel;

[0069] S2-3. Observe the grouting effect and adjust the grouting pressure and flow rate according to actual needs to ensure that the fire extinguishing agent fully fills the cracks;

[0070] S3. Fire fighting:

[0071] S3-1, when a fire occurs, immediately start the driving motor 6 of the spray assembly 5 to drive the centrifugal wheel 53 to rotate;

[0072] S3-2, the lifting plate 7 is driven to lift and slide by the lifting cylinder 8, and the opening gap size of the spraying assembly 5 is changed by adjusting the rotation angle of the guide plate 52, thereby adjusting the flow rate and range of the spraying fire extinguishing agent;

[0073] S3-3, stirring the fire extinguishing agent: When the centrifugal wheel 53 rotates, it drives the stirring assembly 56 to rotate in the opposite direction, stirring the fire extinguishing agent sprayed from the opening of the side wall of the spraying assembly 5 to increase its foaming degree.

Claims

1. An intermittent grouting fire prevention and extinguishing device for coal mine goaf, characterized in that: It comprises a plurality of arch supports (1), which are sequentially attached to the inner wall of a tunnel in a coal mine goaf to provide support; A distributor (3), arranged on the arch support (1), for distributing the fire extinguishing agent; A main pipeline (2) is used for conveying fire extinguishing agent and is connected to the branch pipe (3); A grouting rod (4), one end of which is connected to the manifold (3), and the other end of which passes through the top of the arch support (1) and penetrates into the roof of the goaf, and is used to inject a fire extinguishing agent into the roof for preventive grouting; The spraying assembly (5) is connected below the manifold (3) and is used to spray the fire extinguishing agent into the goaf space.

2. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 1 is characterized in that: A plurality of fire extinguishing agent outlets are provided above the manifold (3), and the fire extinguishing agent outlets are used to connect one end of a grouting rod (4).

3. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 1 is characterized in that: The spray assembly (5) comprises a cylindrical outer shell (51), and a plurality of openings are distributed on the side wall of the outer shell (51); a centrifugal wheel (53) is rotatably connected inside the outer shell (51), and the middle part of the centrifugal wheel (53) is connected to the manifold (3); the fire extinguishing agent enters the middle part of the centrifugal wheel (53) from the manifold (3), and enters the outer shell (51) through the side of the centrifugal wheel (53); and a driving motor (6) is fixed below the outer shell (51).

4. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 3 is characterized in that: A guide plate (52) is rotatably arranged in each of the openings, one side of the guide plate (52) is connected to a rotating shaft, and the rotating shaft is rotatably connected to the upper and lower surfaces of the shell (51), thereby forming a gap at the opening of the side wall of the shell (51); the size of the gap of the opening of the side wall of the shell (51) is changed by rotating the angle of the guide plate (52), thereby adjusting the flow rate and range of spraying the fire extinguishing agent.

5. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 4 is characterized in that: The lower end of the rotating shaft of the guide plate (52) passes through the outside of the outer shell (51), and a rotating rod (54) arranged vertically therewith is fixed to the lower end of the rotating shaft; a lifting plate (7) that can be raised and lowered is arranged below the outer shell (51), and a plurality of universal rods (55) are distributed on the lifting plate (7) along its circumference, one end of the universal rod (55) is connected to the lifting plate (7), and the other end of the universal rod (55) is connected to each of the rotating rods (54); the lifting plate (7) is driven by a lifting cylinder (8), and the lifting cylinder (8) drives the lifting plate (7) to rise and fall along the axial direction of the outer shell (51), so that each universal rod (55) synchronously drives the corresponding rotating rod (54) to rotate, thereby adjusting the rotation angle of each guide plate (52).

6. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 3 is characterized by: A stirring assembly (56) is rotatably arranged between each two adjacent guide plates (52) in the housing (51).

7. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 6, characterized in that: A gear (58) is fixed above the stirring assembly (56), a gear ring (57) is fixed above the centrifugal wheel (53), and the gear ring (57) is meshed with each of the gears (58).

8. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 6, characterized in that: The stirring assembly (56) comprises an upper shaft (561), the upper shaft (561) is coaxially fixed with the gear (58), and a lower shaft (562) is slidably connected below the upper shaft (561); a plurality of upper stirring rods (563) are hingedly connected circumferentially around the upper shaft (561), and a plurality of lower stirring rods (564) are hingedly connected circumferentially around the lower shaft (562); the upper stirring rod (563) and the lower stirring rod (564) are hingedly connected to each other; and the angle between the upper stirring rod (563) and the lower stirring rod (564), i.e. the opening amplitude, is changed by raising and lowering the axial sliding of the lower shaft (562).

9. The intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 8, characterized in that: The lower end of the lower shaft (562) is rotatably connected to a connecting cover (565), a lifting shaft (59) is fixed below the connecting cover (565), the lifting shaft (59) slides through the bottom plate of the outer shell (51) and is fixedly connected to the lifting plate (7), and the lifting shaft (59) moves up and down under the drive of the lifting plate (7).

10. The method for using the intermittent grouting fire prevention and extinguishing device for coal mine goaf according to claim 9, characterized in that: The specific steps include: S1. Device installation: S1-1, attaching a plurality of arch supports (1) to the inner wall of the tunnel in the goaf of the coal mine in sequence, ensuring that the supports are stable and provide support; S1-2, fix the manifold (3) in the arch support (1), and install the main pipeline (2), so that the manifold (3) is connected with the main pipeline (2), so as to ensure that the fire extinguishing agent can be evenly distributed; S1-3, a plurality of grouting rods (4) are fixedly installed on the top of each support (1), ensuring that the grouting rods can penetrate into the roof of the goaf; S1-4, fixing the spraying assembly (5) below each manifold (3) respectively, to ensure that the spraying assembly can accurately spray the fire extinguishing agent into the goaf space; S2. Preventive grouting: S2-1, adjusting the grouting pressure and flow rate of the grouting rod (4) according to the tunnel conditions and crack conditions; S2-2, injecting a fire extinguishing agent into the interior of the top plate through a grouting rod (4) to perform preventive grouting to block the air leakage channel; S2-3. Observe the grouting effect and adjust the grouting pressure and flow rate according to actual needs to ensure that the fire extinguishing agent fully fills the cracks; S3. Fire fighting: S3-1, when a fire occurs, immediately start the drive motor (6) of the spray assembly (5) to drive the centrifugal wheel (53) to rotate; S3-2, driving the lifting plate (7) to lift and slide by means of the lifting cylinder (8), and changing the size of the opening gap of the spraying assembly (5) by adjusting the rotation angle of the guide plate (52), thereby adjusting the flow rate and range of the spraying fire extinguishing agent; S3-3, stirring the fire extinguishing agent: when the centrifugal wheel (53) rotates, it drives the stirring assembly (56) to rotate in the opposite direction, stirring the fire extinguishing agent sprayed from the opening of the side wall of the spraying assembly (5), thereby increasing the degree of foaming thereof.

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