A large-dip-angle working face goaf grouting fire prevention and extinguishing system and method

Abstract

The application discloses a large-dip-angle working face goaf grouting fire prevention and extinguishing system and method, which comprises a stirring and mixing system, a solidified foam injection system and a thickened slurry injection system. The stirring and mixing system reciprocates in a stirring pool through a traveling stirrer at a specific traveling speed, and meanwhile, stirring blades rotate and stir water and loess in the stirring pool during the reciprocation, so that regional turbulent flow is formed to ensure sufficient stirring of the loess and water. Then, the solidified foam material or the thickened material is uniformly sprayed into the slurry in the regional turbulent flow in the form of reverse helix, so that the solidified foam material or the thickened material, water and loess are fully and uniformly mixed through the mutual cooperation of the forward and reverse directions. Finally, the prepared solidified foam slurry and thickened slurry are injected into the goaf through the solidified foam injection system and the thickened slurry injection system in sequence, so that the amount of grouting required is greatly reduced under the premise of ensuring that the goaf at a deep position is fully covered.

Description

Technical Field

[0001] This invention relates to a grouting fire prevention and extinguishing system and method, specifically a grouting fire prevention and extinguishing system and method for goaf areas in steeply inclined working faces, belonging to the field of coal mine goaf fire prevention and extinguishing technology. Background Technology

[0002] my country is rich in mineral resources, and coal remains the main source of energy consumption. After coal is mined from the working face, the roof collapses behind it, forming goaf areas. These areas contain large amounts of residual coal, which are prone to spontaneous combustion and fires. With the increasing mechanization of coal mining and the faster pace of deep mining in my country, the area of ​​goaf areas has expanded, and the amount of residual coal has increased, making the fire hazard in goaf areas more prominent, resulting in a high incidence and significant damage from fires.

[0003] In steeply inclined working faces, the large dip angle and irregular collapse of the roof coal and rock during mining lead to more concealed spontaneous combustion of residual coal, increasing the difficulty of fire prevention and control. Furthermore, existing thickened slurries, gels, three-phase foams, and inhibitors, after injection, often fail to achieve uniform mixing during preparation, resulting in uneven distribution of components within the slurry. Some slurries exhibit unsatisfactory viscosity and flowability, causing some to flow rapidly downwards after injection into the goaf, failing to fully cover the depths of the goaf and reducing fire prevention and extinguishing effectiveness, significantly increasing the difficulty of fire suppression. Additionally, the presence of fissures beneath the goaf in steeply inclined working faces allows thickened slurry to enter these fissures, resulting in material waste. Therefore, based on these two issues, currently, it is necessary to continuously increase the injection volume of thickened slurry to achieve comprehensive coverage of the depths of the goaf, which continuously increases grouting costs and hinders its widespread application.

[0004] Therefore, providing a system and method that can effectively achieve uniform mixing during the grout preparation stage and reduce the amount of grout entering the fissures below the goaf during subsequent grouting, thereby significantly reducing the amount of grout required while ensuring full coverage of the depth within the goaf, is one of the research directions in this industry. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a grouting fire prevention and extinguishing system and method for goaf areas in steeply inclined working faces. It can effectively achieve uniform mixing during the grout preparation stage and reduce the amount of grout entering the fissures below the goaf during subsequent grouting. Thus, while ensuring full coverage of the depth within the goaf, it greatly reduces the amount of grout required.

[0006] To achieve the above objectives, the technical solution adopted by this invention is: a grouting fire prevention and extinguishing system for goaf areas in steeply inclined working faces, comprising a mixing system, a solidifying foam injection system, and a thickening slurry injection system. The mixing system is located on the surface, while the solidifying foam injection system and the thickening slurry injection system are both located inside the mine. The mixing system includes a traveling mixing device, a slurry pool, a slurry retarding pool, and a slurry pump.

[0007] The traveling mixing device includes a slurry collection channel and multiple mixing tanks. Each mixing tank is rectangular and arranged in parallel with each other. The main outlet pipe of the slurry collection channel is connected to the slurry pool, and multiple inlet branch pipes of the slurry collection channel are respectively connected to one end of each mixing tank, for the purpose of collecting the slurry after mixing in each mixing tank and transporting it to the slurry pool.

[0008] Each mixing tank is equipped with a travel track, and each travel track is fitted with a traveling mixer. The traveling mixer includes a support frame, a rotary motor, stirring blades, a feeder, a discharge pipe, a planetary gear set, and a fixed connecting frame. Multiple track wheels are mounted on both sides of the support frame, each track wheel resting on the travel track. One of the track wheels is connected to the traveling motor; the rotation of the traveling motor drives the track wheels to rotate, causing the traveling mixer to reciprocate along the travel track. The rotary motor is mounted inside the support frame, with its drive shaft facing the bottom of the mixing tank. The stirring blades are coaxially connected to the drive shaft via flanges, allowing the drive shaft to rotate synchronously with the stirring blades, mixing the slurry in the mixing tank. There are two feeders. The feeders are symmetrically arranged on both sides of the rotary motor, and each feeder is equipped with universal pulleys at its lower part. A concentric circular track is provided on the support with the rotary motor as the center. The two feeders are mounted on the concentric circular track via their respective universal pulleys. The fixed connecting frame is fixedly connected to the drive shaft in the middle and to the two feeders at both ends. When the drive shaft rotates, it can drive the two feeders to rotate synchronously along the concentric circular track. Each feeder has a connecting pipe at its lower part, and a discharge valve is installed on the connecting pipe. The connecting pipe is coaxially connected to the discharge pipe through a sealed bearing, allowing the connecting pipe and the discharge pipe to rotate independently. The planetary gear set is connected to the drive shaft and the two discharge pipes respectively, so that when the drive shaft rotates, it can drive the two discharge pipes to rotate in opposite directions.

[0009] The slurry pool and the slurry retarding pool are connected by pipelines to transport the slurry in the slurry pool to the slurry retarding pool. The slurry retarding pool is equipped with a fixed mixer to continuously stir the slurry and to transport the slurry to the solidified foam injection system and the thickened slurry injection system through a slurry pump and grouting pipe.

[0010] Furthermore, the discharge port of the discharge pipe is a T-shaped tee. This structure allows the material to be discharged in a spiral spray pattern, resulting in more uniform mixing.

[0011] Furthermore, the shape of the stirring blade matches the bottom of the mixing tank, and its material is silicon carbide fiber. This ensures the strength of the stirring blade and enables better mixing of the slurry in the mixing tank.

[0012] Furthermore, the transmission ratio between the drive shaft and the discharge pipe is 1:4. This transmission ratio allows the discharge pipe to rotate three times faster than the drive shaft, resulting in better pulping performance.

[0013] Furthermore, the bottom of the mixing tank is arc-shaped. This shape facilitates the mixing of the slurry by the agitator blades.

[0014] The working method of the above-mentioned grouting fire prevention and extinguishing system for the goaf of steeply inclined working faces includes the following specific steps:

[0015] Step 1, System Layout: First, determine the inclination direction of the steep working face. Then, place the solidified foam injection system in the roadway near the lower part of the goaf area of ​​the working face, and place the thickened slurry injection system in the roadway near the higher part of the goaf area of ​​the working face. Next, complete the assembly of the mixing system and connect it to the solidified foam injection system and the thickened slurry injection system respectively.

[0016] Step 2: Preparation and Injection of Solidified Foam Slurry: First, set the required travel speed and stirring speed for the solidified foam slurry preparation. According to the required proportions, inject water and yellow mud into each mixing tank separately, and place the solidified foam material into the two feeders. At this time, the discharge valve is closed. Start the travel motor and rotary motor, causing the travel mixer to reciprocate along the mixing tank at the set travel speed. Simultaneously, the drive shaft of the rotary motor drives the mixing blades and the two feeders to rotate synchronously at the set stirring speed. This allows the mixing blades to rotate and stir the water and yellow mud during the reciprocating motion, thereby forming regional turbulence to ensure thorough mixing of the loess and water. After a period of time, open the discharge valve. Because the drive shaft rotates, it can drive the two discharge pipes to rotate in opposite directions, and the rotation speed of the discharge pipes is greater than the rotation speed of the drive shaft. Two feeders rotate synchronously with the drive shaft. At this time, the solidified foam material is evenly sprayed into the regionally turbulent slurry through the discharge pipe in a spiral pattern, achieving a thorough and uniform mixing of the solidified foam material, water, and yellow mud. After a period of time, the solidified foam slurry prepared in each mixing tank is collected in the slurry pool through the slurry collection channel and then transported to the slurry retarding tank. The fixed mixer in the slurry retarding tank continuously stirs the incoming slurry to ensure that the solidified foam slurry does not clump when injected into the goaf. The solidified foam slurry is then transported to the solidified foam injection system through the slurry pump and grouting pipe. The solidified foam injection system injects the slurry into the intersection of the goaf and the roadway through the pre-embedded pipe. The solidified foam slurry solidifies rapidly in the goaf, sealing the cracks below the goaf. After completion, the mixing system stops working.

[0017] Step 3: Preparation and Injection of Thickened Slurry: Reset the travel speed and stirring speed required for thickened slurry preparation. Inject water and yellow mud into each mixing tank according to the required ratio, and place the thickened slurry material into the two feeders. At this time, the discharge valve is closed. Start the travel motor and rotary motor, causing the travel mixer to reciprocate along the mixing tank at the set travel speed. Simultaneously, the drive shaft of the rotary motor drives the stirring blades and the two feeders to rotate synchronously at the set stirring speed. This allows the stirring blades to rotate and stir the water and yellow mud during the reciprocating motion, thus forming regional turbulence to ensure thorough mixing of loess and water. After a period of time, open the discharge valve. Because the drive shaft rotates, it drives the two discharge pipes to rotate in opposite directions, and the rotation speed of the discharge pipes is greater than that of the drive shaft. Furthermore, the two feeders continue to rotate synchronously with the drive shaft. At this time, the thickened slurry material... The slurry is evenly sprayed in a spiral pattern through the discharge pipe into the regionally turbulent slurry, achieving thorough and uniform mixing of the thickened slurry material, water, and yellow mud. After a period of time, the thickened slurry prepared in each mixing tank is collected in a slurry pool and then transported to a slurry retarding tank via a slurry collection channel. The fixed mixer in the slurry retarding tank continuously stirs the incoming slurry to ensure that the thickened slurry does not clump when injected into the goaf. The thickened slurry is then transported to the thickened slurry injection system via a slurry pump and grouting pipe. The thickened slurry injection system injects the slurry into the high part of the goaf through a pre-embedded pipe. The thickened slurry slowly flows down the slope from the high part of the goaf, covering the entire goaf up to the lower part of the working face. Because the fissures below the goaf are sealed by solidified foam, the slurry will not enter the fissures after flowing, ultimately achieving complete coverage of the depth of the goaf. After completion, the mixing system stops working.

[0018] Compared with existing technologies, the present invention combines a mixing system, a solidified foam injection system, and a thickened slurry injection system, which has the following advantages:

[0019] 1. The mixing system of the present invention can prepare solidified foam slurry and thickened slurry separately. In the preparation process, by first setting the travel speed and stirring speed, the traveling mixer moves back and forth in the mixing tank at a specific travel speed. At the same time, the stirring blades rotate and stir the water and yellow mud in the mixing tank during the reciprocating motion, thereby forming regional turbulence to ensure that the loess and water are fully mixed. Then, the discharge valve is opened, and the solidified foam material or thickened material in the feeder is discharged from the discharge pipe through the connecting pipe. Since the discharge pipe rotates in opposite directions through the planetary gear set when the drive shaft rotates, and the rotation speed of the discharge pipe is greater than the rotation speed of the drive shaft, the solidified foam material or thickened material is evenly sprayed into the slurry in the regional clockwise turbulence in the form of a counterclockwise spiral. This forward and reverse mutual cooperation realizes the full and uniform mixing of solidified foam material or thickened material, water and yellow mud, and finally prepares solidified foam slurry and thickened slurry with excellent uniformity, ensuring the required performance of the subsequent slurry.

[0020] 2. In this invention, during injection, a solidified foam slurry is first prepared and injected into the lower part of the goaf area of ​​the working face through a solidified foam injection system. This solidified foam seals the cracks below the goaf area, preventing the subsequent thickened slurry from flowing into the cracks, thus avoiding failure to cover the working face and wasting materials. Then, a thickened slurry is prepared and injected from the higher part of the goaf area through a thickened slurry injection system. At this time, the thickened slurry slowly flows along the inclined direction, covering the entire goaf area up to the lower part of the working face. Since the cracks below the goaf area are sealed by the solidified foam, it will not enter the cracks after flowing, ultimately achieving complete coverage of the depth within the goaf area and saving slurry volume.

[0021] 3. When performing fire prevention and extinguishing grouting in each goaf area, this invention first determines the component ratios of the solidified foam grout and the thickened grout based on the dip angle and internal fissures of the goaf area. Then, multiple tests are conducted using the system of this invention to adjust the travel speed and stirring speed during preparation. The transmission ratio between the drive shaft and the discharge pipe is adjusted by adjusting the planetary gear set. Finally, the optimal travel speed, stirring speed, and planetary gear set for preparing the solidified foam grout and the thickened grout are determined to achieve the best results. Subsequent fire prevention and extinguishing grouting is performed with the optimal parameters, thereby ensuring comprehensive coverage of the depth within each goaf area and providing better applicability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a cross-sectional view of the traveling stirring device in this invention;

[0024] Figure 3 yes Figure 2Top view.

[0025] In the diagram: 1-mixing tank, 2-traveling mixer, 3-slurry collection channel, 4-slurry pool, 5-slurry retarder, 6-stationary mixer, 7-slurry pump, 8-grouting pipe, 9-solidified foam injection system, 10-thickened slurry, 11-solidified foam slurry, 12-support, 13-feeder, 14-rotary motor, 15-universal pulley, 16-concentric track, 17-track wheel, 18-traveling track, 19-discharge valve, 20-sealed bearing, 21-discharge pipe, 22-fixed connecting frame, 23-drive shaft, 24-flange, 25-mixing blade, 26-planetary gear set. Detailed Implementation

[0026] The present invention will be further described below.

[0027] like Figure 1 As shown, a grouting fire prevention and extinguishing system for goaf areas in steeply inclined working faces includes a mixing system, a solidified foam injection system 9, and a thickened slurry injection system. The mixing system is located on the surface, while the solidified foam injection system 9 and the thickened slurry injection system are both located inside the mine. The mixing system includes a traveling mixing device, a slurry pool 4, a slurry retarder 5, and a slurry pump 7.

[0028] The traveling mixing device includes a slurry collection channel 3 and multiple mixing tanks 1. Each mixing tank 1 is rectangular and arranged in parallel with each other. The main outlet pipe of the slurry collection channel 3 is connected to the slurry pool 4. Multiple inlet branch pipes of the slurry collection channel 3 are respectively connected to one end of each mixing tank 1, which are used to collect the slurry after mixing in each mixing tank 1 and transport it to the slurry pool 4.

[0029] like Figure 2 and 3As shown, each mixing tank 1 is equipped with a traveling track 18, and each traveling track 18 is equipped with a traveling mixer 2. The traveling mixer 2 includes a support 2, a rotary motor 14, a stirring blade 25, a feeder 13, a discharge pipe 21, a planetary gear set 26, and a fixed connecting frame 22. Multiple track wheels 17 are mounted on both sides of the support 2, and each track wheel 17 is located on the traveling track 18. One of the track wheels 17 is connected to the traveling motor. When the traveling motor rotates, it drives the track wheel 17 to rotate, causing the traveling mixer 2 to reciprocate along the traveling track 18. The rotary motor 14 is installed inside the support 2, and the drive shaft 23 of the rotary motor 14 faces the bottom of the mixing tank 1. The stirring blade 25 is coaxially connected to the drive shaft 23 through a flange 24, so that when the drive shaft 23 rotates, it drives the stirring blade 25 to rotate synchronously to stir and mix the slurry in the mixing tank 1. There are two feeders 13, and the two feeders 13 are connected to the feeder 2. The feeders 13 are mounted on both sides of the rotary motor 14, and each feeder 13 is equipped with a universal pulley 15 at its lower part. A concentric circular track 16 is provided on the support 2 with the rotary motor 14 as the center. The two feeders 13 are mounted on the concentric circular track 16 via their respective universal pulleys 15. The fixed connecting frame 22 is fixedly connected to the drive shaft 23 in the middle and to the two feeders 13 at both ends. When the drive shaft 23 rotates, it can drive the two feeders 13 to rotate synchronously along the concentric circular track 16. Each feeder 13 has a connecting pipe at its lower part, and a discharge valve 19 is installed on the connecting pipe. The connecting pipe is coaxially connected to the discharge pipe 21 through a sealed bearing 20, allowing the connecting pipe and the discharge pipe 21 to rotate independently. The planetary gear set 26 is connected to the drive shaft 23 and the two discharge pipes 21 respectively, so that when the drive shaft 23 rotates, it can drive the two discharge pipes 21 to rotate in opposite directions. The discharge port of the discharge pipe 21 is a T-shaped tee. This structure allows the material to be discharged from the discharge pipe 21 in a spiral spray pattern, resulting in more uniform mixing.

[0030] The slurry pool 4 and the slurry retarding pool 5 are connected by pipelines, used to transport the slurry in the slurry pool 4 to the slurry retarding pool 5; the slurry retarding pool 5 is equipped with a fixed mixer 6 for continuous mixing of the slurry, and the slurry is transported to the solidified foam injection system 9 and the thickened slurry injection system through the slurry pump 7 and the grouting pipe 8. The solidified foam injection system 9 and the thickened slurry injection system are both existing structures in the mine.

[0031] As an improvement of the present invention, the bottom of the mixing tank 1 is arc-shaped. This shape facilitates the stirring of the slurry by the stirring blades 25; the shape of the stirring blades 25 matches the bottom of the mixing tank 1, and their material is silicon carbide fiber. This ensures the strength of the stirring blades 25 and enables better stirring and mixing of the slurry in the mixing tank 1.

[0032] A working method for a grouting fire prevention and extinguishing system in the goaf of a steeply inclined working face, comprising the following specific steps:

[0033] Step 1, System Layout: First, determine the inclination direction of the steep working face. Place the solidified foam injection system 9 in the roadway near the lower part of the goaf area of ​​the working face, and place the thickened slurry injection system in the roadway near the higher part of the goaf area of ​​the working face. Then, complete the assembly of the mixing system and connect it to the solidified foam injection system 9 and the thickened slurry injection system respectively. The transmission ratio between the drive shaft 23 and the discharge pipe 21 is 1:4 through the adjustment of the planetary gear set 26. This transmission ratio makes the discharge pipe 21 rotate 3 times faster than the drive shaft 23, achieving a better slurry preparation effect.

[0034] Step 2: Preparation and Injection of Solidified Foam Slurry: First, set the required travel speed and stirring speed for the solidified foam slurry preparation. According to the required proportions, inject water and yellow mud into each mixing tank 1, and place the solidified foam material into the two feeders 13. At this time, the discharge valve 19 is closed. Start the travel motor and rotary motor 14, causing the traveling mixer 2 to reciprocate along the mixing tank 1 at the set travel speed. Simultaneously, the drive shaft of the rotary motor 14 drives the stirring blades 25 and the two feeders 13 to rotate clockwise synchronously at the set stirring speed. This allows the stirring blades 25 to rotate and stir the water and yellow mud during the reciprocating motion, thus forming regional clockwise turbulence to ensure thorough mixing of the loess and water. After a period of time, open the discharge valve 19. Because the drive shaft 23 can drive the two discharge pipes 21 to rotate counterclockwise when rotating, and the rotation speed of the discharge pipes 21 is greater than the rotation speed of the drive shaft 23, and the two feeders... The feeder 13 rotates clockwise along with the drive shaft 23. At this time, the solidified foam material is evenly sprayed into the slurry in a counterclockwise spiral pattern through the discharge pipe 21. By combining forward and reverse methods, the solidified foam material, water and yellow mud are fully and evenly mixed. After a period of time, the solidified foam slurry prepared in each mixing tank 1 is collected in the slurry pool 4 through the slurry collection channel 3 and then transported to the slurry slowing tank 5. The fixed mixer 6 in the slurry slowing tank 5 continuously stirs the incoming slurry to ensure that the solidified foam slurry 11 will not clump when injected into the goaf. The solidified foam slurry 11 is then transported to the solidified foam injection system 9 through the slurry pump 7 and the grouting pipe 8. The solidified foam injection system 9 injects the solidified foam slurry into the intersection of the goaf and the roadway through the pre-embedded pipe. The solidified foam slurry 11 solidifies rapidly in the goaf and seals the cracks below the goaf. After completion, the mixing system stops working.

[0035] Step 3: Preparation and Injection of Thickened Slurry: Reset the travel speed and stirring speed required for thickened slurry preparation. Inject water and yellow mud into each mixing tank 1 according to the required proportions, and place the thickened slurry material into the two feeders 13. At this time, the discharge valve 19 is closed. Start the travel motor and rotary motor 14, causing the traveling mixer 2 to reciprocate along the mixing tank 1 at the set travel speed. Simultaneously, the drive shaft 23 of the rotary motor 14 drives the stirring blades 25 and the two feeders 13 to rotate clockwise synchronously at the set stirring speed. This allows the stirring blades 25 to rotate and stir the water and yellow mud during the reciprocating motion, thus forming regional clockwise turbulence to ensure thorough mixing of the loess and water. After a period of time, open the discharge valve 19. Because the drive shaft 23 can drive the two discharge pipes 21 to rotate counterclockwise when rotating, and the rotation speed of the discharge pipes 21 is greater than that of the drive shaft 23... The rotation speed of the 3 is such that the two feeders 13 continuously rotate clockwise synchronously with the drive shaft 23. At this time, the thickened slurry material is evenly sprayed into the regional clockwise turbulent slurry through the discharge pipe 21 in the form of a counterclockwise spiral. Through the combination of forward and reverse methods, the thickened slurry material, water and yellow mud are fully and evenly mixed. After a period of time, the thickened slurry prepared by each mixing tank 1 is collected by the slurry pool 4 through the slurry collection channel 3 and then transported to the slurry slowing tank 5. The fixed mixer 6 of the slowing tank 5 continuously stirs the incoming slurry to ensure that the thickened slurry 10 will not clump when injected into the goaf. The thickened slurry 10 is transported to the thickened slurry injection system through the slurry pump 7 and the grouting pipe 8. The thickened slurry injection system is injected into the high place of the goaf of the working face through the pre-embedded pipe. During grouting, a filter plate can be placed at the grouting port to prevent large particles of sediment from entering the grouting pipeline and causing blockage. Thickened slurry 10 flows slowly from the high point of the goaf along the inclined direction, covering the entire goaf up to the low point of the working face. Because the fissures below the goaf are sealed by solidified foam, it will not enter the fissures after flowing, ultimately achieving complete coverage of the depth of the goaf. After completion, the mixing system stops working. By injecting thickened slurry + solidified foam fire prevention and extinguishing technology, corresponding pipelines are buried in the "spontaneous combustion zone" of the goaf or at the junction of the "spontaneous combustion zone" and the "oxidation zone" to inject fire prevention and extinguishing materials, thereby effectively preventing spontaneous combustion of coal remaining in the "spontaneous combustion zone" of the goaf.

[0036] The ratios of the solidified foam slurry 11 and the thickened slurry 10 mentioned above are known ratios in the industry. In addition, the travel speed and stirring speed required for the preparation of the solidified foam slurry 11 and the thickened slurry 10 mentioned above can be determined by conducting experiments in advance to find the optimal parameters, thereby ensuring that the solidified foam slurry and the thickened slurry are prepared to the best effect.

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A working method for a grouting fire prevention and extinguishing system in the goaf of a steeply inclined working face, characterized in that, The system includes a mixing system, a solidified foam injection system, and a thickened slurry injection system. The mixing system is located on the ground and includes a traveling mixer, a slurry pool, a slurry retarder, and a slurry pump. The traveling mixer includes a slurry collection channel and multiple mixing pools, each rectangular and arranged parallel to each other. The main outlet pipe of the slurry collection channel is connected to the slurry pool, and multiple inlet branch pipes of the slurry collection channel are connected to one end of each mixing pool to collect the slurry mixed in each pool and transport it to the slurry pool. Each mixing pool has... Each mixing tank is equipped with a travel track, and each travel track is fitted with a traveling mixer. The traveling mixer includes a support frame, a rotary motor, stirring blades, a feeder, a discharge pipe, a planetary gear set, and a fixed connecting frame. Multiple track wheels are mounted on both sides of the support frame, and each track wheel is positioned on the travel track. One of the track wheels is connected to the traveling motor; when the traveling motor rotates, it drives the track wheels to rotate, causing the traveling mixer to reciprocate along the travel track. The rotary motor is installed inside the support frame, with its drive shaft facing the bottom of the mixing tank. The stirring blades are coaxially connected to the drive shaft via flanges, allowing the main... When the drive shaft rotates, it drives the stirring blades to rotate synchronously, stirring and mixing the slurry in the mixing tank. There are two feeders, symmetrically arranged on both sides of the rotary motor, each with a universal pulley at its lower part. A concentric circular track is provided on the support with the rotary motor as the center. The two feeders are mounted on the concentric circular track via their respective universal pulleys. The fixed connecting frame is fixedly connected to the drive shaft in the middle and to the two feeders at both ends. When the drive shaft rotates, it drives the two feeders to rotate synchronously along the concentric circular track. Each feeder has a connecting... The connecting pipe is equipped with a discharge valve. The connecting pipe is coaxially connected to the discharge pipe via a sealed bearing, allowing the connecting pipe and discharge pipe to rotate independently. The planetary gear set is connected to the drive shaft and the two discharge pipes respectively, enabling the drive shaft to rotate the two discharge pipes in opposite directions. The slurry pool and the slurry retarder are connected by pipelines to transport the slurry from the slurry pool to the retarder. The retarder is equipped with a fixed mixer for continuous mixing of the slurry, and the slurry is transported to the solidified foam injection system and the thickened slurry injection system via a slurry pump and injection pipe. The specific steps are as follows: Step 1, System Layout: First, determine the inclination direction of the steep working face. Then, place the solidified foam injection system in the roadway near the lower part of the goaf area of ​​the working face, and place the thickened slurry injection system in the roadway near the higher part of the goaf area of ​​the working face. Next, complete the assembly of the mixing system and connect it to the solidified foam injection system and the thickened slurry injection system respectively. Step 2: Preparation and Injection of Solidified Foam Slurry: First, set the required travel speed and stirring speed for solidified foam slurry preparation. According to the required proportions, inject water and yellow mud into each mixing tank separately, and place the solidified foam material into the two feeders. At this time, the discharge valve is closed. Start the travel motor and rotary motor. After a period of time, open the discharge valve. The solidified foam material is evenly sprayed through the discharge pipe in a spiral pattern into the slurry in the regionally turbulent state, achieving thorough and uniform mixing of the solidified foam material, water, and yellow mud. After a period of time, through... The slurry collection channel gathers the solidified foam slurry prepared in each mixing tank and then transports it to the slurry retarding tank. The fixed mixer in the slurry retarding tank continuously stirs the incoming slurry to ensure that the solidified foam slurry does not clump when injected into the goaf. The solidified foam slurry is then transported to the solidified foam injection system via a slurry pump and injection pipe. The solidified foam injection system injects the slurry into the intersection of the goaf and the roadway through a pre-embedded pipe. The solidified foam slurry solidifies rapidly in the goaf, sealing the cracks below the goaf. Once this is completed, the mixing system stops operating. Step 3: Preparation and Injection of Thickened Slurry: Reset the travel speed and stirring speed required for thickened slurry preparation. Inject water and yellow mud into each mixing tank according to the required proportions, and place the thickened slurry material into the two feeders. At this time, the discharge valve is closed. Start the travel motor and rotary motor. After a period of time, open the discharge valve. The thickened slurry material is evenly sprayed into the regionally turbulent slurry through the discharge pipe in a spiral pattern, achieving thorough and uniform mixing of the thickened slurry material, water, and yellow mud. After a period of time, the thickened slurry prepared in each mixing tank is collected in the slurry pool via the slurry collection channel. The slurry is transported to a slurry retarding tank, where a fixed mixer continuously agitates the incoming slurry to ensure that the thickened slurry does not clump when injected into the goaf. The thickened slurry is then transported to a thickened slurry injection system via a slurry pump and injection pipe. This system injects the slurry into the higher part of the goaf through pre-embedded pipes. The thickened slurry flows slowly down the slope from the higher part of the goaf, covering the entire goaf up to the lower part of the working face. Because the cracks below the goaf are sealed by solidified foam, the slurry will not enter the cracks after flowing, ultimately achieving complete coverage of the depth within the goaf. Once completed, the mixing system is stopped.

2. The working method according to claim 1, characterized in that, The discharge port of the discharge pipe is a T-shaped tee.

3. The working method according to claim 1, characterized in that, The shape of the stirring blade matches the bottom of the mixing tank, and its material is silicon carbide fiber.

4. The working method according to claim 1, characterized in that, The transmission ratio between the drive shaft and the discharge pipe is 1:

4.

5. The working method according to claim 1, characterized in that, The bottom of the mixing tank is arc-shaped.

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