Device for quickly forming filling column on rear side of fully-mechanized coal mining hydraulic support of coal mine

Abstract

The device comprises a filling workbench, a three-way grouting pipe and a filling mold, the filling workbench is arranged on the lower portion of the rear side of the fully-mechanized mining hydraulic support, the filling mold is arranged on the rear side of the filling workbench, and the rear end of the three-way grouting pipe communicates with the interior of the filling mold; a filling hydraulic baffle is arranged on the upper portion of the rear side of the fully-mechanized mining hydraulic support. The filling mold comprises a mold top plate, a mold front side plate, a mold rear side plate, a mold left baffle and a mold right baffle, a plurality of mold cross braces which are arranged in parallel up and down are arranged between the mold front side plate and the mold rear side plate, the bottoms of the mold front side plate and the mold rear side plate are placed on the coal seam bottom plate, and an exhaust hole is formed in the front part of the mold top plate. According to the utility model, the goaf is filled and isolated at intervals behind the coal mining working face, and the technical problems that the existing device is large in assembly and disassembly workload, long in filling body maintenance time and low in mining efficiency due to difficulty in guaranteeing mining and filling balance are effectively solved.

Description

Technical Field

[0001] This utility model belongs to the field of green backfilling mining technology in coal mines, specifically relating to a device for rapidly forming backfilling columns on the rear side of a fully mechanized hydraulic support in coal mines. Background Technology

[0002] Coal mining has made a significant contribution to ensuring my country's energy security and promoting industrial economic development. However, the ecological damage and resource waste caused by coal mining also constrain the sustainable development of coal-producing areas. First, coal mine production generates 10% to 20% of coal gangue, with an annual increase of 650 to 700 million tons since 2011, accumulating to over 8 billion tons, resulting in severe ground pollution and land occupation. Second, the use of caving methods in coal mines to treat abandoned areas damages the groundwater system, lowers or even eliminates aquifers, expands the area of ​​surface subsidence, and damages the surface morphology and the safety of buildings and structures. Third, my country has a huge amount of coal resources buried under buildings, railways, and water bodies, as well as marginal coal resources, affecting the continuous production of coal mines.

[0003] Cemented coal gangue backfilling mining offers significant advantages in coal-based solid waste disposal and utilization, surface subsidence control, and environmental protection, and has become a major method of green coal mining. However, large-scale production mines face challenges in cemented coal gangue backfilling, including complex backfill material preparation processes, poor slurry transport stability, insufficient backfill gangue volume, high backfilling costs, and difficulty in achieving a balance between mining and backfilling.

[0004] Cemented backfilling mining of the goaf after the longwall face is a large-scale backfilling mining method. It requires the erection of templates before backfilling the goaf, and the backfill material must harden to the required strength before the next steps of coal cutting and template relocation can proceed. Balancing coal mining and backfilling operations is difficult, limiting the working face's production capacity. Furthermore, the large-area backfilling operation in the goaf requires the construction of large-scale backfilling stations for large-scale slurry preparation and pipeline transportation. The coal mine's own coal gangue aggregate volume is insufficient, making it difficult to guarantee the stability of the backfilling system. Therefore, a device with high stability and high subsidence treatment efficiency is needed to quickly construct inter-column backfilling structures behind the hydraulic supports in longwall mining. Utility Model Content

[0005] To address the shortcomings of existing technologies, this invention provides a device that offers high stability, high efficiency in handling subsidence, and the ability to quickly construct inter-column columns in fully mechanized coal mines, thereby rapidly forming inter-column columns behind the goaf filling structures.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A device for rapidly forming a filling column on the rear side of a fully mechanized hydraulic support in a coal mine includes a filling workbench, a three-way grouting pipe, and a filling mold. The filling workbench is located at the lower rear side of the fully mechanized hydraulic support, and the filling mold is located on the rear side of the filling workbench. The rear end of the three-way grouting pipe is connected to the interior of the filling mold. A filling hydraulic baffle is provided on the upper rear side of the fully mechanized hydraulic support.

[0008] The filling mold includes a mold top plate, a mold front plate, a mold rear plate, a mold left baffle, and a mold right baffle. Several mold cross braces are arranged vertically and horizontally between the mold front plate and the mold rear plate. The bottom of the mold front plate and the mold rear plate are placed on the coal seam bottom plate. A vent is provided at the front of the mold top plate.

[0009] The front end of the mold cross brace is connected to the front side plate of the mold, and the rear end of the mold cross brace is connected to the rear side plate of the mold. Expansion bolt structures are provided between the front end of the mold cross brace and the front side plate of the mold, and between the mold cross brace and the rear side plate of the mold.

[0010] The front and rear side plates of the mold have the same structure, both including an upper side plate, a middle side plate, and a lower side plate. The top of the upper side plate is connected to the front end of the mold top cover. The bottom of the upper side plate and the bottom of the middle side plate are provided with connecting protrusions. The top of the middle side plate and the top of the lower side plate are provided with connecting grooves corresponding to the connecting protrusions. Locking buckles are provided at the connection between the upper side plate and the middle side plate and at the connection between the middle side plate and the lower side plate.

[0011] A front connecting plate assembly and a rear connecting plate assembly are provided between the left baffle and the right baffle of the mold. The front connecting plate assembly and the rear connecting plate assembly have the same structure, each including a left connecting plate, a middle connecting plate and a right connecting plate. The left end of the left connecting plate, the middle connecting plate and the right connecting plate are provided with trapezoidal grooves, and the right end of the left connecting plate, the middle connecting plate and the right connecting plate are provided with trapezoidal protrusions corresponding to the trapezoidal grooves. The right end of the left baffle of the mold is provided with trapezoidal protrusions, and the left end of the right baffle of the mold is provided with trapezoidal grooves.

[0012] An anchor rod is installed between the bottom layer of the mold cross brace and the coal seam floor. The bottom end of the anchor rod is fastened to the inside of the coal seam floor, and the top end of the anchor rod is connected to the bottom layer of the mold cross brace.

[0013] In practical use, the device is first assembled behind the hydraulic support; then, filling slurry is injected into the device, and after the filling slurry has achieved early strength, the device is moved as the working face advances to prevent the fracture zone in the goaf behind the working face from developing into the water-resistant layer; after the filling slurry hardens, it forms filling columns. At this point, a new device is assembled and moved so that the device forming the filling columns is completely placed within the goaf; this cycle is repeated until a row of filling columns is formed along the length of the working face.

[0014] In summary, this utility model is simple to operate and highly stable. It can be used to control the development range of caving zones and fracture zones, effectively solving the technical problems of large workload in device assembly and disassembly, long curing time of backfill body, and difficulty in ensuring mining-backfill balance, which leads to low mining efficiency. It is conducive to promoting pillarless mining, promoting the full development and utilization of coal resources, and realizing safe, efficient, green and sustainable mining of coal mines. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model.

[0016] Figure 2 This is a structural schematic diagram of the filling mold of this utility model.

[0017] Figure 3 yes Figure 2 Enlarged view of section B in the middle.

[0018] Figure 4 yes Figure 2 Enlarged view of section C.

[0019] Figure 5 This is a left-side view of the filling mold of this utility model.

[0020] Figure 6 yes Figure 2 A cross-sectional view of plane AA.

[0021] Figure 7 yes Figure 6 Enlarged view of section A.

[0022] Figure 8 This is a schematic diagram of the structure for water-conserving mining in the goaf area with filling columns according to this utility model. Detailed Implementation

[0023] like Figures 1-8 As shown, the device for rapidly forming a filling column on the rear side of a fully mechanized hydraulic support in a coal mine includes a filling workbench 2, a three-way grouting pipe 3, and a filling mold 9. The filling workbench 2 is located at the lower rear side of the fully mechanized hydraulic support 1, and the filling mold 9 is located at the rear side of the filling workbench 2. The rear end of the three-way grouting pipe 3 is connected to the interior of the filling mold 9. A filling hydraulic baffle 5 is provided on the upper rear side of the fully mechanized hydraulic support 1. The grouting pipe suspended in the filling operation space behind the hydraulic support 1 of the fully mechanized working face 24 is a three-way grouting pipe 3. The spacing of the filling branch pipes can be set according to the length of the filling mold 9. A PLC controller and a corresponding liquid level sensor can also be set to automatically control the filling pipe valve by sensing the liquid level position of the filling slurry 7 in the filling mold 9 when it is about to be filled.

[0024] The filling mold 9 includes a mold top plate, a mold front side plate 10, a mold rear side plate 13, a mold left baffle 16, and a mold right baffle 18. Several mold cross braces 6 are arranged vertically and horizontally between the mold front side plate 10 and the mold rear side plate 13. The bottom of the mold front side plate 10 and the mold rear side plate 13 are placed on the coal seam bottom plate 14. A vent hole 4 is opened at the front of the mold top plate. During the grouting process, the gas in the filling mold 9 is discharged from the vent hole 4 to ensure the uniformity of the distribution of the filling slurry 7. The filling mold 9 is assembled in sections at the start of the cut and is assembled close to the filling workbench 2 under the protection of the filling hydraulic baffle 5. The length of one section of the mold is the total width of one frame movement, and the width of the mold is equal to the coal mining step distance of one cut. After assembly, it moves forward with the advancement of the working face 24 under the protection of the filling hydraulic baffle 5. The moving distance is such that the fracture zone above the caving zone cannot develop to the aquitard 20 (the filling mold 9 moves with the hydraulic support 1 for an integer multiple of the coal mining depth, and this dimension controls the development of the roof fracture zone to the aquitard 20). Early strength filling slurry 7 is injected into the mold through the three-way grouting pipe 3. The filling body and the mold together form the filling inter-column 27. The filling inter-column 27 isolates the goaf 26 in sections, controls the range of roof caving and the depth of fracture expansion, and protects the aquitard 20 and the aquifer 19. After the filling material reaches early strength, the hydraulic support 1 is moved one section depth. Under the protection of the filling hydraulic baffle 5, a new device is quickly assembled between the filling workbench 2 and the previous filling column 27. After assembly, it moves forward a small goaf 26 span as the working face 24 advances, and then injects early-strength filling slurry 7 to form the second filling column 27. The front end of the mold cross brace 6 is connected to the front side plate 10 of the mold, and the rear end of the mold cross brace 6 is connected to the rear side plate 13 of the mold. Expansion bolt structures 11 are provided between the front end of the mold cross brace 6 and the front side plate 10 of the mold, and between the mold cross brace 6 and the rear side plate 13 of the mold. Through the tenon joint of the expansion bolt structure 11, the stability of the filling mold 9 can be improved, and the side plate can be prevented from excessively deforming under the action of horizontal stress of gangue and hydrostatic pressure of slurry. The filling of the inter-pillar 27 separates the goaf 26, transforming the continuous collapse of the roof into intermittent collapse, effectively controlling the range of the caving zone and fracture zone, protecting the aquifer 19 and the surface, and effectively treating coal gangue, realizing parallel mining and filling operations, and improving the efficiency of green mining.

[0025] The front side plate 10 and the rear side plate 13 of the mold have the same structure, both including an upper side plate, a middle side plate and a lower side plate. The top of the upper side plate is connected to the front end of the mold top cover 15. The bottom of the upper side plate and the bottom of the middle side plate are provided with connecting protrusions 29. The top of the middle side plate and the top of the lower side plate are provided with connecting grooves 30 corresponding to the connecting protrusions 29. Locking buckles 12 are provided between the connection between the upper side plate and the middle side plate and between the connection between the middle side plate and the lower side plate.

[0026] A front connecting plate assembly and a rear connecting plate assembly are provided between the left baffle 16 and the right baffle 18 of the mold. The front connecting plate assembly and the rear connecting plate assembly have the same structure, each including a left connecting plate, a middle connecting plate and a right connecting plate. The left end of the left connecting plate, the middle connecting plate and the right connecting plate is provided with a trapezoidal groove 32, and the right end of the left connecting plate, the middle connecting plate and the right connecting plate is provided with a trapezoidal protrusion 31 corresponding to the trapezoidal groove 32. The right end of the left baffle 16 of the mold is provided with a trapezoidal protrusion 31, and the left end of the right baffle 18 of the mold is provided with a trapezoidal groove 32. Through the embedded connection of the connecting groove 30 and the connecting protrusion 29, and the embedded connection of the trapezoidal groove 32 and the trapezoidal protrusion 31, the filling mold 9 can withstand the hydrostatic pressure of the filling slurry 7 in all directions. After the filling mold 9 is assembled, it is linked with the filling workbench 2 behind the frame to prevent falling gangue from flowing into the filling operation area 25. The assembly of the filling mold 9, the filling grouting, and the coal cutting by the coal mining machine are carried out simultaneously. After the grouting in the filling mold 9 is completed and the filling body forms early strength, the hydraulic support 1 is moved one step distance. The resulting filling inter-column 27 is still under the protection of the filling hydraulic baffle 5. A new filling mold 9 is assembled between the filling workbench 2 and the filling inter-column 27. It moves with the working face 24 to the allowable interval distance of the goaf 26. After grouting, a new filling inter-column is constructed. After the inter-column interacts with the roof, it changes the stress distribution of the roof together with the previous filling inter-column, isolates several discontinuous small goaf 26, and restricts the formation of the water-conducting channel of the water-proof layer 20 above the goaf 26.

[0027] In practical use, the device of this application is first assembled behind the hydraulic support 1; then, filling slurry 7 is injected into the device of this application, and after the filling slurry 7 has formed early strength, the device of this application is moved as the working face 24 advances to prevent the fracture zone of the goaf 26 behind the working face 24 from developing to the aquitard 20; after the filling slurry 7 hardens, filling columns 27 are formed. At this time, a new device is assembled and moved so that the device forming the filling columns 27 is completely placed in the goaf 26; this cycle is repeated until a row of filling columns 27 is formed along the length of the working face 24. The above steps are repeated, and the filling columns 27 change the continuous roof collapse under the traditional coal mining method to intermittent collapse, isolate the continuous goaf 26 into the intermittent goaf 26, effectively control the expansion range of the collapse zone and fracture zone, avoid the generation of fractures in the aquitard 20, protect the aquifer 19, prevent surface subsidence, and effectively treat coal gangue to prevent gangue from accumulating on the ground and causing environmental pollution in the mining area. During installation, firstly, the filling workbench 2 is installed on the rear side of the hydraulic support 1; then, the filling mold 9 is assembled close to the filling workbench 2, so that the filling workbench 2 provides horizontal support for the filling mold 9; a three-way grouting pipe 3 is installed on the upper side plate of the filling mold 9, and early-strength filling grout 7 is injected into the mold through the three-way grouting pipe 3. Before grouting, anchor bolts 8 are installed on the coal seam floor 14 for fixation. The top of the anchor bolt 8 is connected to the bottommost mold cross brace 6, and the lower end of the anchor bolt 8 is fastened inside the coal seam floor 14 to prevent the filling mold 9 from floating during grouting; finally, the filling hydraulic baffle 5 is installed on the upper rear side of the hydraulic support 1. When installing the mold, first assemble the front side plate 10 and the rear side plate 13 of the mold. The upper side plate, the middle side plate, and the lower side plate are installed together through the connecting protrusion 29 and the connecting groove 30, and the connection is locked with the locking buckle 12. Then, the mold top cover 15 is installed between the top of the front side plate 10 and the rear side plate 13 of the mold. Several mold cross braces 6 are installed vertically and parallel between the front side plate 10 and the rear side plate 13 of the mold through the expansion bolt structure 11. Then, assemble the front connecting plate assembly and the rear connecting plate assembly of the mold. The left connecting plate, the middle connecting plate, and the right connecting plate are assembled together through the trapezoidal groove 32 and the trapezoidal protrusion 31. Finally, the left baffle 16 of the mold is installed at the left end of the front connecting plate assembly and the rear connecting plate assembly, and the right baffle 18 of the mold is installed at the right end of the front connecting plate assembly and the rear connecting plate assembly. Furthermore, the assembly and grouting of the filling mold 9 are carried out in parallel with the coal mining operation of the working face 24. The filling slurry 7 used is supplemented with an early-strength agent and must be able to form early strength within 12 hours. A quick-setting agent is added during grouting. The early hardening of the filling body should be completed at the end of the inspection shift, so as not to affect the advancement and frame shifting of the working face 24, and to ensure the safety of the new mold assembly operation after the frame shifting. Alternatively, a group-interval frame shifting method can be adopted, so that the hardening of the filling body, the assembly of the new mold, and the frame shifting are carried out alternately. The length of each section of the filling mold 9 is equal to the total width of one frame shifting, and the width of each section of the filling mold 9 is equal to the coal mining step distance of one cut.The filling mold 9 is made of lightweight, high-strength, and plastic material, which can be cast integrally, resulting in low cost. The filling mold 9 is transported to the working face 24 and quickly assembled under the protection of the filling hydraulic baffle 5, reducing manual labor intensity. Robotic assistance can also be used to improve efficiency and reduce manpower. Furthermore, to improve the efficiency of handling subsidence in the goaf 26, some coal mines use methods such as delamination grouting, high-level drilling grouting, adjacent grouting, and low-level grouting in the goaf 26. Delamination grouting requires geological conditions where the key rock stratum 23 delamination occurs; the key stratum is thick and has easily deformable rock strata 23 below it. Grouting in the goaf 26 is prone to grout leakage, polluting the working face 24 and the retreat roadway, requiring a large amount of sealing work. High-level drilling is costly, and drilling accuracy is difficult to control at greater mining depths, and drilling in fracture zones is difficult. Adjacent grouting and low-level grouting involve complex underground filling and drainage pipeline layouts, requiring a large amount of manual work. In this application, the filling mold 9 is assembled and grouting is carried out in parallel with coal mining after the 24th frame of the fully mechanized mining face. The filling mold 9 adopts a tenon-and-mortise and nested structure for rapid segmented assembly. A quick-setting agent is added to form the early strength of the filling body. The filling column 27 is composed of the filling mold 9 and the filling body formed by the hardened filling slurry 7. No demolding is required. The filling operation is flexible and safe, with low manual labor intensity, easy intelligent control, and easy to achieve mining-filling balance.

[0028] This application, through the support of the backfill pillars 27 on the roof 21 of the coal seam, transforms the continuous collapse of the goaf 26 under traditional mining methods into intermittent collapse, forming an intermittent goaf 26 isolated by the backfill pillars 27. This significantly reduces the range of the goaf 26, effectively controls the expansion of the caving and fracture zones, prevents the development of induced fractures under the aquitard 20, blocks water-conducting channels, protects the aquifer 19, and inhibits surface subsidence. This application is simple and convenient to operate and can be used for mining overlying coal seams 22 and corner coal seams. It effectively solves the technical problems of large dismantling workload, long backfill curing time, and difficulty in ensuring mining-backfill balance, leading to low mining efficiency. Furthermore, it facilitates the advancement of pillarless mining, promotes the full development and utilization of coal resources, and achieves safe, efficient, green, and sustainable coal mining.

[0029] This embodiment does not impose any limitation on the shape, material, structure, etc. of this utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this utility model shall fall within the protection scope of this utility model.

Claims

1. A device for rapidly forming a filling column behind a fully mechanized hydraulic support in a coal mine, characterized in that: It includes a filling workbench, a three-way grouting pipe, and a filling mold. The filling workbench is located at the lower rear side of the fully mechanized hydraulic support, and the filling mold is located at the rear side of the filling workbench. The rear end of the three-way grouting pipe is connected to the interior of the filling mold. A filling hydraulic baffle is provided at the upper rear side of the fully mechanized hydraulic support. The filling mold includes a mold top plate, a mold front plate, a mold rear plate, a mold left baffle, and a mold right baffle. Several mold cross braces are arranged vertically and horizontally between the mold front plate and the mold rear plate. The bottom of the mold front plate and the mold rear plate are placed on the coal seam bottom plate. A vent is provided at the front of the mold top plate.

2. The device for rapidly forming a filling column on the rear side of a fully mechanized hydraulic support in coal mines according to claim 1, characterized in that: The front end of the mold cross brace is connected to the front side plate of the mold, and the rear end of the mold cross brace is connected to the rear side plate of the mold. Expansion bolt structures are provided between the front end of the mold cross brace and the front side plate of the mold, and between the mold cross brace and the rear side plate of the mold.

3. The device for rapidly forming a filling column on the rear side of a fully mechanized hydraulic support in coal mines according to claim 2, characterized in that: The front and rear side plates of the mold have the same structure, both including an upper side plate, a middle side plate, and a lower side plate. The top of the upper side plate is connected to the front end of the mold top cover. The bottom of the upper side plate and the bottom of the middle side plate are provided with connecting protrusions. The top of the middle side plate and the top of the lower side plate are provided with connecting grooves corresponding to the connecting protrusions. Locking buckles are provided at the connection between the upper side plate and the middle side plate and at the connection between the middle side plate and the lower side plate.

4. The device for rapidly forming a filling column on the rear side of a fully mechanized hydraulic support in coal mines according to claim 3, characterized in that: A front connecting plate assembly and a rear connecting plate assembly are provided between the left baffle and the right baffle of the mold. The front connecting plate assembly and the rear connecting plate assembly have the same structure, each including a left connecting plate, a middle connecting plate and a right connecting plate. The left end of the left connecting plate, the middle connecting plate and the right connecting plate are provided with trapezoidal grooves, and the right end of the left connecting plate, the middle connecting plate and the right connecting plate are provided with trapezoidal protrusions corresponding to the trapezoidal grooves. The right end of the left baffle of the mold is provided with trapezoidal protrusions, and the left end of the right baffle of the mold is provided with trapezoidal grooves.

5. The device for rapidly forming a filling column on the rear side of a fully mechanized hydraulic support in coal mines according to claim 4, characterized in that: An anchor rod is installed between the bottom layer of the mold cross brace and the coal seam floor. The bottom end of the anchor rod is fastened to the inside of the coal seam floor, and the top end of the anchor rod is connected to the bottom layer of the mold cross brace.

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