A system for filling a gob in a mine

Abstract

The application discloses a kind of goaf filling system underground, it is related to underground filling technical field, and the system will be divided into goaf filling, and the upper and lower two-way multi-point dispersion grouting structure is formed by pipe jacking and tiltable adjustable grid pipe, can realize all-around dead angle grouting filling to stone accumulation gap, cooperate with self-adaptive plugging slurry outlet protection structure, can effectively prevent stone debris blockage slurry outlet, avoid partial lack of slurry, broken slurry defect.The grid pipe can swing and disturb stone, eliminate stacked air gap, and improve stone filling density.Meanwhile, the built-in air bag of grid pipe can squeeze out the residual slurry in pipe after operation, eliminate slurry waste and pipeline solidification blockage.In addition, the system uses modular detachable structure, most components can be recycled, and subarea construction can reuse existing support structure.Effectively solve the problem of uneven distribution of traditional filling slurry, low consolidation strength, improve the goaf filling quality and operation efficiency, reduce construction cost.

Description

Technical Field

[0001] This invention relates to the field of underground filling technology, specifically to an underground goaf filling system. Background Technology

[0002] Underground goaf backfilling is a core technology for managing goaf areas, preventing roof collapse, and ensuring safety during underground operations in coal mines. Currently, the industry commonly uses stone stacking and grouting backfilling, which involves filling the goaf with crushed stones to form a basic support framework, and then injecting consolidation grout to solidify the stones into a whole, thereby achieving the filling and reinforcement of the goaf. However, existing traditional backfilling processes and supporting equipment have significant technical defects in practical applications. The core problem lies in the inability to uniformly deliver grout into the gaps between the filling stones, which seriously affects the overall backfilling and consolidation strength of the goaf.

[0003] Existing filling equipment mostly adopts a single-point or unidirectional grouting structure, which limits the grouting range. After the stone is piled up, a large number of irregular and interwoven small gaps and cavities will be formed inside. Traditional grouting mode is difficult to achieve all-round, dead-angle-free grout dispersion filling.

[0004] This problem directly leads to a significant decrease in the stability of the filling material, making it unable to effectively resist the effects of underground mine pressure. This can easily cause the filling material to crack, break, or even fail completely, leading to safety hazards such as roof subsidence and collapse. At the same time, uneven filling of the slurry will also result in inconsistent filling quality, which seriously restricts the filling and treatment effect of underground goaf areas and fails to meet the construction requirements of safe and high-strength filling in modern mines. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a downhole goaf filling system.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a goaf filling system, which divides the goaf into multiple zones, each filling zone including a pair of symmetrically arranged support frames located at the inner and outer ends of the zone respectively; multiple jacking pipes are installed between the top ends of the two support frames, the multiple jacking pipes are evenly distributed along the length direction of the support frames, and each jacking pipe has multiple downward-facing second slurry outlets along its own length direction;

[0007] Multiple partition components are evenly spaced along the height direction between the two support frames. Each partition component includes an end rod and multiple grid tubes. The end rod is detachably installed on the inner end support frame. The multiple grid tubes are evenly spaced along the length direction of the end rod and are detachably connected to the end rod. Each grid tube has multiple first slurry outlets with upward and downward openings evenly spaced along its own length direction. A fixing plate is fixedly welded to the inside of the end of the grid tube away from the end rod.

[0008] Multiple support rods are detachably installed on the outer end support frame. Each support rod corresponds to a partition component. Multiple support grooves are equally spaced along the length of the support rod. The support grooves are used to support the end of the limiting grid tube.

[0009] A sealing plate is detachably installed on the outer side of the outer end support frame. The sealing plate has multiple through holes that match the grid tube, and the end of the grid tube passes through the corresponding through holes.

[0010] Both support frames have grouting channels inside. The grouting channels of the two support frames are interconnected through multiple jacking pipes. All end rods on the inner end support frame are connected to the grouting channels of the inner end support frame. The internal cavities of the grid pipe are interconnected after being connected to the end rods. A grouting port is fixedly installed on the outer end support frame. The grouting port is connected to the grouting channels of the outer end support frame and is used to deliver filling grout into the system.

[0011] The goaf area is equipped with a crushing and screening machine and a conveyor. The conveyor is used to transport the stone to be crushed to the crushing and screening machine. The crushed and screened stone is used for filling the goaf area in different zones.

[0012] Preferably, the end rod has multiple communication ports at equal intervals along its length, and an adapter sleeve is fitted on the outer wall of the end rod at the position corresponding to each communication port. A threaded sleeve is fixedly connected to the outside of the adapter sleeve. A threaded head is fixedly installed at one end of the grid tube near the end rod. The threaded head and the threaded sleeve are threadedly matched and connected to each other, so as to realize the detachable connection and fixation between the grid tube and the end rod.

[0013] Preferably, the adapter sleeve is rotatably sleeved with the outer wall of the end rod, and a U-shaped block is fixedly installed on the outer wall of the end rod below each adapter sleeve; the bottom of the adapter sleeve is provided with a fitting part that fits with the U-shaped block, and the U-shaped block limits the adapter sleeve by supporting the fitting part, restricting the rotation of the adapter sleeve, so that the threaded sleeve is always kept horizontally arranged.

[0014] Preferably, a sealing ring is provided on the outer side of each grid tube and at the position corresponding to each first slurry outlet, and two adjacent sealing rings are fixedly connected by a connecting rod to form an integral sealing ring assembly;

[0015] A connecting block is fixedly installed on the inner side of a sealing ring near the outer end support frame. The connecting block is slidably adapted to the inner wall of the corresponding first slurry outlet. A movable rod is fixedly connected to the outer side of the connecting block. The movable rod passes through the center of the fixed plate and slides with the fixed plate. A movable plate is fixedly installed at the outer end of the movable rod. A spring is fixedly connected between the opposite end faces of the movable plate and the fixed plate. The spring is sleeved on the outer side of the movable rod.

[0016] The inner side of the end of the grid tube near the fixed plate is integrally formed with an internal thread, and a threaded rod is threadedly fitted onto the internal thread, and a push rod is fixedly installed on the outer end of the threaded rod.

[0017] Preferably, an elastic airbag is fixedly embedded on the inner side of each of the grid tubes, and the airbag is connected to an air supply pipe assembly that extends to the outside of the grid tube.

[0018] Before the grouting of a single section is completed and the grid pipe is recycled, the air bladder is inflated by the air supply pipe group. The inflated air bladder squeezes the residual grout inside the grid pipe and squeezes the residual grout inside the pipe completely into the filling section. After the grout inside the grid pipe is emptied, the grid pipe is extracted and recycled as a whole.

[0019] Preferably, the air supply pipe assembly includes an air supply pipe, a bend, a connector, and a valve. One end of the air supply pipe is sealed and fixedly connected to the airbag, and the other end of the air supply pipe is fixedly connected to the connector. The connector extends through the bend to the outside of the end of the grid pipe, and the valve is fixedly installed at the connector to control the inflation and depressurization of the airbag.

[0020] Preferably, mounting rings are fixedly installed at both ends of the end rod along its length, and a first bolt passes through the mounting ring. The mounting ring is detachably and fixedly connected to the inner end support frame through the first bolt, and the support frame has a threaded groove that matches the first bolt.

[0021] When constructing continuous filling in goaf areas, after the previous area is filled, its outer end support frame can be reused as the inner end support frame for the next area. Only one new outer end support frame is needed to complete the construction of the next area, thus realizing continuous and progressive filling construction in the area.

[0022] Preferably, mounting blocks are fixedly installed at both ends of the support rod along its length, and multiple second bolts are passed through the mounting blocks. The mounting blocks are detachably and fixedly connected to the outer end support frame through the second bolts; a notch is provided at the bottom of the sealing plate to avoid the mounting structure.

[0023] Compared with the prior art, the present invention provides a downhole goaf filling system, which has the following beneficial effects:

[0024] 1. By employing a bidirectional, multi-point, diffused grouting structure, replacing the traditional single-point, unidirectional grouting method, it can comprehensively fill irregular gaps formed by stone accumulation without dead angles. Simultaneously, it features an adaptive sealing grout outlet protection structure, which can prevent debris intrusion during the stone filling stage, completely avoiding grout outlet blockage and localized grout shortages. This effectively eliminates voids and gaps within the filling body, ensuring the stone and grout fully solidify into a unified whole, significantly improving filling density and structural integrity, enhancing the compressive bearing capacity of the filling body, and mitigating safety hazards such as roof settlement and collapse.

[0025] 2. During the stone filling process, the ends of the grid pipes can be tilted to disturb the piled stones, causing them to shake, compact, and rearrange themselves, effectively eliminating gaps and loose voids caused by stone stacking. Simultaneously, it can assist in the inward sliding of stones, increasing the amount of stone filling within the goaf, avoiding problems of loose or voided stone filling, laying a solid foundation for subsequent uniform grouting and consolidation, and further improving the overall filling quality.

[0026] 3. An inflatable elastic airbag structure is installed inside the grid pipe. Before grouting is completed and the pipe is recycled, the airbag expands and squeezes out any residual grout inside the pipe, completely expelling the grout trapped inside and filling it into the goaf gaps. This effectively solves the problems of grout retention and pipe blockage caused by traditional grouting pipes. It avoids grout waste, ensures full and complete grout filling of the goaf gaps, prevents grout from solidifying and sticking to pipes, avoids pipe blockage and scrapping, ensures the integrity and standardization of each filling operation, and improves the quality of the finished filling product.

[0027] 4. Adopting a fully modular and detachable assembly design, unlike traditional fixed filling structures, most functional components can be disassembled, recycled, and reused after filling operations are completed. Simultaneously, the zonal progressive construction mode for goaf areas allows for the reuse of existing support structures, eliminating the need to repeatedly build the entire set of equipment and significantly reducing the investment in new equipment and materials. The recyclable structure effectively reduces material losses and equipment procurement costs in underground filling operations, simplifies construction and disassembly procedures, reduces the accumulation of consumables in underground operations, and balances economic efficiency and environmental protection, adapting to the needs of large-scale, routine goaf filling operations in mines.

[0028] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0029] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0030] Figure 1 This is a schematic diagram of one side of the structure in this invention;

[0031] Figure 2 This is a schematic diagram of the structure on the other side of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the grid tube and the end rod in this invention;

[0033] Figure 4 This is a schematic diagram of the structure of the grid tube and the sealing ring in this invention;

[0034] Figure 5 This is a schematic diagram of the sealing ring assembly in this invention;

[0035] Figure 6 This is a schematic diagram showing the disassembled structure of the threaded rod, the grid tube, and the adapter sleeve in this invention;

[0036] Figure 7 This is a schematic cross-sectional view of the grid tube and threaded rod in this invention;

[0037] Figure 8 This is a schematic diagram of the structure of the airbag, air delivery pipe, bend, connector, and valve in this invention;

[0038] Figure 9 This is a schematic diagram of the structure of the end rod and the adapter sleeve in this invention;

[0039] Figure 10 This is a schematic diagram of the sealing plate in this invention;

[0040] Figure 11 This is a schematic diagram of the support rod in this invention.

[0041] In the diagram: 1. Support frame; 11. Grouting port; 12. Jacking pipe;

[0042] 2. Grille tube; 21. First slurry outlet; 22. Threaded head; 23. Fixing plate; 24. Internal thread section;

[0043] 3. End rod; 31. Connecting port; 32. U-shaped block; 33. Mounting ring; 34. First bolt;

[0044] 4. Support rod; 41. Support groove; 42. Mounting block; 43. Second bolt;

[0045] 5. Sealing ring; 51. Connecting rod; 52. Connecting block; 53. Movable rod; 54. Movable plate; 55. Spring;

[0046] 6. Airbag; 61. Air supply pipe; 62. Bend; 63. Connector; 64. Valve;

[0047] 7. Sealing plate; 71. Perforation; 72. Notch;

[0048] 8. Adapter sleeve; 81. Threaded sleeve; 82. Fitting part;

[0049] 9. Threaded rod; 91. Push rod. Detailed Implementation

[0050] The following is in conjunction with the appendixFigures 1-11 The principles and features of the present invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0051] It should be noted that when a component is described as "fixed to" another component, it can be directly on the other component or may have a component in between. When a component is considered "connected to" another component, it can be directly connected to the other component or may have a component in between. When a component is considered "set on" another component, it can be directly set on the other component or may have a component in between. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0052] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0053] This embodiment discloses an underground goaf filling system. In practical application, the underground goaf to be filled is first divided into multiple independent filling zones. Each filling zone is constructed sequentially. Each filling zone is equipped with a pair of support frames 1. The pair of support frames 1 are respectively installed at the inner and outer ends of the filling zone, serving as the main support foundation structure of the entire filling system to ensure the stability of equipment installation and the safety of filling operations.

[0054] Multiple jacking pipes 12 are installed between the tops of the two support frames 1. These pipes 12 are evenly distributed at equal intervals along the length of the support frame 1, with the spacing adjustable according to the cross-sectional dimensions of the goaf and the diffusion properties of the filling grout to ensure complete grout coverage at the top. Each jacking pipe 12 has multiple downward-facing secondary grout outlets evenly distributed along its length. The filling grout can be diffused downwards through these outlets, achieving grout filling in the upper part of the goaf, eliminating voids, and preventing future roof collapse. Hollow grout delivery channels are provided inside both support frames 1. These channels are interconnected through the internal pipes of the multiple jacking pipes 12, forming a continuous top grout delivery path. A grouting port 11 is fixedly installed on the outer wall of the outer support frame 1. The grouting port 11 is sealed and connected to the grout delivery channel inside the outer support frame 1, allowing external grouting equipment to deliver filling grout to the entire system through the grouting port 11, providing a foundation for the overall filling operation.

[0055] Multiple partition components are evenly spaced along the height direction in the space between the two support frames 1. The multi-layer partition components can divide the interior of the filling zone into layers, realizing layered filling and grouting, and greatly improving the filling density. Each partition component includes an end rod 3 and multiple grid tubes 2. The end rod 3 is detachably assembled on the support frame 1 at the inner end of the zone. The multiple grid tubes 2 are evenly spaced along the length direction of the end rod 3, and each grid tube 2 is detachably connected to the end rod 3, which facilitates equipment disassembly and assembly, zone adaptation, and subsequent recycling and reuse.

[0056] The grating pipe 2 is made of high-strength, wear-resistant, and corrosion-resistant alloy steel, possessing high compressive strength, resistance to underground moisture and corrosion, and resistance to deformation and damage. It can withstand long-term stone extrusion and slurry erosion, making it suitable for complex underground operating environments. The sealing ring assembly for the grating pipe 2 is made of high-toughness, wear-resistant engineering plastic, combining lightweight, high wear resistance, and anti-aging advantages. It can effectively slide against the wall of the grating pipe 2, while avoiding wear failure caused by friction with stones and slurry, ensuring a sealing and protective effect. Each grating pipe 2 has multiple first slurry outlets 21 evenly spaced along its length. The first slurry outlets 21 are arranged in two ways: opening upwards and opening downwards, enabling bidirectional slurry discharge to fill the gaps between stones from all directions, completely solving the problems of uneven filling and local voids caused by slurry discharge from one side. A fixing plate 23 is fixedly welded to the end of the grid tube 2 away from the end rod 3. An internal thread 24 is integrally formed on the inner side of the end of the grid tube 2 close to the fixing plate 23. The internal thread 24 is integrally formed with the grid tube 2, which has high structural strength and good thread accuracy, and can stably match the thread rod 9 to realize thread transmission assembly.

[0057] The end rod 3 has multiple connecting ports 31 spaced evenly along its length. Each connecting port 31 is fitted with a set of adapter sleeves 8, which are rotatably mounted on the outer wall of the end rod 3. A threaded sleeve 81 is fixedly connected to the outer side of the adapter sleeve 8. A threaded head 22 is fixedly installed at the end of the grid tube 2 closest to the end rod 3. The threaded head 22 and the threaded sleeve 81 are matched in specifications and threaded fit, achieving a tight connection through screwing. This ensures complete communication between the grid tube 2 and the internal cavity of the end rod 3, while also enabling quick assembly and disassembly, improving work efficiency. A U-shaped block 32 is fixedly installed on the outer wall of the end rod 3, below each adapter sleeve 8. An integral fitting part 82 is provided at the bottom of the adapter sleeve 8. The top of the U-shaped block 32 fits against the surface of the fitting part 82, providing support and limiting the adapter sleeve 8. This effectively restricts the adapter sleeve 8 from rotating during operation, ensuring the threaded sleeve 81 remains horizontally positioned. This significantly reduces the alignment difficulty of the grid tube 2 during installation, improving assembly efficiency and sealing.

[0058] Both ends of the end rod 3 are fixedly installed with mounting rings 33 along its length. Each mounting ring 33 is fitted with a first bolt 34. The side wall of the inner end support frame 1 has a threaded groove that matches the first bolt 34. The mounting rings 33 are locked to the inner end support frame 1 by the first bolts 34, realizing the detachable installation and fixation of the end rod 3. The installation and fixation are convenient and the fixation is firm. In the process of continuous filling construction in the goaf, after the filling and reinforcement work of the previous filling section is completed, the outer end support frame 1 of the previous section can be directly reused as the inner end support frame 1 of the next newly added filling section. Only one set of outer end support frames 1 needs to be added to complete the equipment construction of the next section. There is no need to replace the entire support frame 1 structure, which greatly reduces the equipment investment cost, simplifies the construction process, and realizes continuous progressive filling construction in the goaf.

[0059] Multiple support rods 4 are detachably installed on the support frame 1 at the outer end of the partition. Each support rod 4 corresponds to a partition component, and each support rod 4 supports the end of the grid tube 2 of a partition component. Multiple support grooves 41 are evenly spaced along the length of the support rod 4. The groove shape and size of the support grooves 41 match the diameter of the grid tube 2. The end of the grid tube 2 away from the end rod 3 can be inserted into the support groove 41 to achieve precise support and positioning, effectively preventing the grid tube 2 from shifting under force and sagging deformation, and ensuring the horizontality and stability of the grid tube 2. Mounting blocks 42 are fixedly installed at both ends of the support rod 4 along its length. Multiple second bolts 43 are passed through each mounting block 42. The mounting blocks 42 are locked to the side wall of the outer end support frame 1 by the second bolts 43, realizing the detachable assembly of the support rod 4.

[0060] A sealing plate 7 is detachably installed on the outer side of the outer end support frame 1. The sealing plate 7 completely covers the outer port of the filling section, achieving section sealing and preventing the overflow of stone and slurry. Multiple through holes 71 matching the diameter of the grid pipes 2 are provided on the sealing plate 7. The outer end of each grid pipe 2 extends through the corresponding through hole 71 to the outside of the sealing plate 7, ensuring both the layout of the grid pipes 2 and the slurry discharge operation are not affected, while also guaranteeing the sealing effect of the sealing plate 7. Simultaneously, a notch 72 is provided at the bottom of the sealing plate 7. The notch 72 effectively avoids interference between the sealing plate 7 and the installation structure of the support frame 1 and support rod 4, ensuring a proper fit and installation of the sealing plate 7.

[0061] Each grid tube 2 has a sealing ring 5 installed on its outer side, corresponding to each first slurry outlet 21. The inner diameter of the sealing ring 5 matches the outer diameter of the grid tube 2, allowing it to slide axially against the wall of the grid tube 2. Adjacent sealing rings 5 ​​are fixedly connected by a rigid connecting rod 51. All sealing rings 5 ​​and connecting rods 51 combine to form an integrated sealing ring assembly, which slides synchronously to ensure the synchronous sealing and opening of all first slurry outlets 21. A connecting block 52 is fixedly installed on the inner side of the outermost sealing ring 5 near the outer end support frame 1. The connecting block 52 slides and fits onto the inner wall of the corresponding first slurry outlet 21, allowing it to slide smoothly along the axial direction of the first slurry outlet 21, providing guidance and limiting for the overall movement of the sealing ring assembly. A movable rod 53 is fixedly connected to the center of the outer side of the connecting block 52. The movable rod 53 passes through the center of the fixed plate 23 and slides with the fixed plate 23, allowing the movable rod 53 to slide freely. A movable plate 54 is fixedly installed on the outer end of the movable rod 53. A spring 55 is fixedly connected between the opposite end faces of the movable plate 54 and the fixed plate 23. The spring 55 is sleeved on the outside of the movable rod 53. The automatic reset and sealing of the sealing ring assembly is achieved by the elastic extension and contraction of the spring 55. A push rod 91 is fixedly installed on the outer end of the threaded rod 9. Tightening the threaded rod 9 can push the movable plate 54 to move, thereby driving the entire sealing ring assembly to slide, realizing the switching between sealing and opening of the first slurry outlet 21.

[0062] Each grid tube 2 has an elastic airbag 6 fixedly embedded in its inner wall. The elastic airbag 6 is made of highly elastic and wear-resistant rubber, which can be stably embedded inside the grid tube 2, and is not easy to fall off or break. The elastic airbag 6 is connected to an air supply pipe assembly, which extends to the outside of the grid tube 2. After the filling operation is completed and before the grid tube 2 is recycled, air can be injected into the elastic airbag 6 through the air supply pipe assembly, so that the elastic airbag 6 can expand rapidly. The expanded airbag can completely squeeze the filling slurry remaining in the cavity of the grid tube 2, and completely squeeze the slurry remaining in the tube into the filling zone, so as to completely avoid material waste and pipeline blockage caused by slurry residue. After the slurry is emptied, the grid tube 2 and the sealing ring assembly can be extracted and recycled as a whole.

[0063] The air supply pipe assembly for the airbag 6 specifically includes an air supply pipe 61, a bend 62, a connector 63, and a valve 64. One end of the air supply pipe 61 is sealed and fixedly connected to the elastic airbag 6 to ensure inflation sealing and eliminate the risk of air leakage. The other end of the air supply pipe 61 is fixedly connected to the connector 63. The connector 63 extends and bends through the bend 62 to the outer side of the end of the grid tube 2, facilitating the connection of external inflation equipment by the operator. The valve 64 is fixedly installed at the connector 63 and is used to precisely control the inflation and depressurization of the airbag 6. When inflating, the valve 64 is opened to complete the pressurization and inflation. After the operation is completed, the valve 64 is closed to maintain the airbag in an inflated state. When depressurizing, the valve 64 is opened to quickly release air, facilitating the reset and recovery of the grid tube 2.

[0064] This invention provides a complete underground goaf filling operation process. During operation, the assembly of the partition support frame 1, jacking pipe 12, partition components, and support rods 4 is completed first. Then, the stone to be crushed is conveyed to the integrated crushing and screening machine in the goaf via a conveyor. After being processed into uniformly sized stone particles by the integrated crushing and screening machine, the stone is evenly placed above each partition component, filling the entire filling partition in layers and eliminating large gaps. After the stone filling is completed, the sealing plate 7 is installed, and filling slurry is then conveyed into the system's slurry delivery channel through the grouting port 11. The slurry enters the jacking pipe 12 and the grid pipe 2 respectively. The jacking pipe 12 discharges slurry downwards through the second slurry outlet, and the grid pipe 2 discharges slurry bidirectionally through the first slurry outlet 21, filling the gaps between the stones from all directions and ensuring a dense filling within the partition. After grouting is completed and the grout has initially solidified, the residual grout in the airbag 6 is first emptied from the air vent pipe. Then, reusable equipment such as the grid pipe 2, sealing ring assembly, and support rod 4 are extracted and recycled. Finally, the perforation 71 of the sealing plate 7 is sealed. After the grout solidifies, the sealing plate 7 is removed and recycled for filling the next section. The support frame 1 and the jacking pipe 12 are retained as permanent support structures, which effectively improves the overall support strength of the goaf after filling, prevents collapse, and has a high equipment reuse rate, good filling effect, and low construction cost.

[0065] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A downhole goaf filling system, characterized in that, The goaf is divided into multiple zones, and each filling zone includes a pair of symmetrically arranged support frames located at the inner and outer ends of the zone, respectively; multiple jacking pipes are erected between the tops of the two support frames, and the multiple jacking pipes are evenly distributed along the length of the support frames, and each jacking pipe has multiple downward-facing second slurry outlets along its own length. Multiple partition components are evenly spaced along the height direction between the two support frames. Each partition component includes an end rod and multiple grid tubes. The end rod is detachably installed on the inner end support frame. The multiple grid tubes are evenly spaced along the length direction of the end rod and are detachably connected to the end rod. Each grid tube has multiple first slurry outlets with upward and downward openings evenly spaced along its own length direction. A fixing plate is fixedly welded to the inside of the end of the grid tube away from the end rod. Multiple support rods are detachably installed on the outer end support frame. Each support rod corresponds to a partition component. Multiple support grooves are equally spaced along the length of the support rod. The support grooves are used to support the end of the limiting grid tube. A sealing plate is detachably installed on the outer side of the outer end support frame. The sealing plate has multiple through holes that match the grid tube, and the end of the grid tube passes through the corresponding through holes. Both support frames have grouting channels inside. The grouting channels of the two support frames are interconnected through multiple jacking pipes. All end rods on the inner end support frame are connected to the grouting channels of the inner end support frame. The internal cavities of the grid pipe are interconnected after being connected to the end rods. A grouting port is fixedly installed on the outer end support frame. The grouting port is connected to the grouting channels of the outer end support frame and is used to deliver filling grout into the system. The goaf area is equipped with a crushing and screening machine and a conveyor. The conveyor is used to transport the stone to be crushed to the crushing and screening machine. The crushed and screened stone is used for filling the goaf area in different zones.

2. The downhole goaf filling system according to claim 1, characterized in that: The end rod has multiple communication ports evenly spaced along its length. An adapter sleeve is fitted on the outer wall of the end rod at the position corresponding to each communication port. A threaded sleeve is fixedly connected to the outside of the adapter sleeve. A threaded head is fixedly installed at one end of the grid tube near the end rod. The threaded head and the threaded sleeve are threadedly matched and connected to each other, so as to realize the detachable connection and fixation between the grid tube and the end rod.

3. The downhole goaf filling system according to claim 2, characterized in that: The adapter sleeve is rotatably sleeved with the outer wall of the end rod. A U-shaped block is fixedly installed on the outer wall of the end rod below each adapter sleeve. The bottom of the adapter sleeve is provided with a fitting part that fits the U-shaped block. The U-shaped block limits the adapter sleeve by supporting the fitting part, restricting the rotation of the adapter sleeve, so that the threaded sleeve is always horizontally arranged.

4. The underground goaf filling system according to claim 1, characterized in that: Each of the grid tubes is provided with a sealing ring on the outside of each first slurry outlet, and two adjacent sealing rings are fixedly connected by a connecting rod to form an integral sealing ring assembly. A connecting block is fixedly installed on the inner side of a sealing ring near the outer end support frame. The connecting block is slidably adapted to the inner wall of the corresponding first slurry outlet. A movable rod is fixedly connected to the outer side of the connecting block. The movable rod passes through the center of the fixed plate and slides with the fixed plate. A movable plate is fixedly installed at the outer end of the movable rod. A spring is fixedly connected between the opposite end faces of the movable plate and the fixed plate. The spring is sleeved on the outer side of the movable rod. The inner side of the end of the grid tube near the fixed plate is integrally formed with an internal thread, and a threaded rod is threadedly fitted onto the internal thread, and a push rod is fixedly installed on the outer end of the threaded rod.

5. A downhole goaf filling system according to claim 1, characterized in that: Each of the grid tubes has an elastic airbag fixedly embedded on its inner side, and the airbag is connected to an air supply pipe assembly that extends to the outside of the grid tube. Before the grouting of a single section is completed and the grid pipe is recycled, the air bladder is inflated by the air supply pipe group. The inflated air bladder squeezes the residual grout inside the grid pipe and squeezes the residual grout inside the pipe completely into the filling section. After the grout inside the grid pipe is emptied, the grid pipe is extracted and recycled as a whole.

6. A downhole goaf filling system according to claim 5, characterized in that: The air supply pipe assembly includes an air supply pipe, a bend, a connector, and a valve. One end of the air supply pipe is sealed and fixedly connected to the airbag, and the other end of the air supply pipe is fixedly connected to the connector. The connector extends through the bend to the outside of the end of the grid pipe. The valve is fixedly installed at the connector and is used to control the inflation and depressurization of the airbag.

7. A downhole goaf filling system according to claim 1, characterized in that: Both ends of the end rod are fixedly installed with mounting rings, and a first bolt passes through the mounting ring. The mounting ring is detachably and fixedly connected to the inner end support frame through the first bolt. The support frame has a threaded groove that matches the first bolt. When constructing continuous filling in goaf areas, after the previous area is filled, its outer end support frame can be reused as the inner end support frame for the next area. Only one new outer end support frame is needed to complete the construction of the next area, thus realizing continuous and progressive filling construction in the area.

8. A downhole goaf filling system according to claim 1, characterized in that: Mounting blocks are fixedly installed at both ends of the support rod along its length. Multiple second bolts are threaded through the mounting blocks, and the mounting blocks are detachably and fixedly connected to the outer end support frame through the second bolts. A notch is provided at the bottom of the sealing plate to avoid the mounting structure.

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