Coal mine goaf surface back water drainage system

Abstract

A coal mine goaf drainage system includes a waterproof wall, drainage pipes, connecting roadways, and drainage tunnels. Its distinguishing feature is the inclusion of timber stacks, a filter screen, a high-pressure submersible pump, a shut-off valve, a backwash device, and a sump. The timber stacks are located at the entrance of the waterproof wall. The filter screen, with a size matching the width of the connecting roadway, is positioned behind the timber stacks. The drainage pipes, consisting of at least two pipes of varying heights, are installed within the waterproof wall, each with a shut-off valve at its outlet. The high-pressure submersible pump is located in the sump and connected to the drainage pipes. The backwash device is positioned between the shut-off valve and the high-pressure submersible pump. This invention solves the problems of large pieces of gangue and coal entering the drainage pipes, causing blockages and making drainage difficult. Furthermore, the timber stacks protect the roof, preventing roof collapse from breaking the pipes and affecting drainage.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, and in particular to a drainage system for the goaf of a coal mine. Background Technology

[0002] Currently, water accumulation in coal mine goaf areas mainly flows out by gravity through the two roadways of the working face. It then flows along pre-laid drainage ditches to pump pits or temporary water tanks, is pumped to the central pump house, and finally discharged to the surface water treatment plant. Once the adjacent roadway construction is completed, goaf water can be drained through the sealed connection of adjacent roadways. It can flow by gravity or through drainage pumps and pipelines to the next drainage point, ultimately reaching the central pump house and surface water treatment plant. However, due to the significant influence of the working face slope, this method is often suitable for downward-facing working faces. For upward-facing working faces, the limitations are significant, often preventing the goaf water from flowing out by gravity, thus affecting safe mining operations. Another method involves sealing the connection with adjacent roadways for drainage. However, due to the large amount of debris and coal gangue in the goaf area, and the lack of support protection at the sealed connection points, the roof is prone to collapse, pipeline breakage, or blockage, resulting in poor drainage. Summary of the Invention

[0003] To address the problems caused by existing working face drainage, a coal mine goaf drainage system is proposed, comprising a waterproof wall, drainage pipes, connecting roadways, and drainage tunnels. The system is characterized by further including timber stacks, a filter screen, a high-pressure submersible pump, a shut-off valve, a backwash device, and a sump. The timber stacks are located at the entrance of the waterproof wall. The filter screen, with a size matching the width of the connecting roadway, is positioned behind the timber stack. The drainage pipes, consisting of at least two pipes of varying heights arranged in a group, are located within the waterproof wall, each with a shut-off valve at its outlet. The high-pressure submersible pump is located within the sump and connected to the drainage pipes. The backwash device is positioned between the shut-off valve and the high-pressure submersible pump.

[0004] Furthermore, the lower drain pipe of the set of drain pipes is at least 20cm away from the roadway floor, the height difference between the upper drain pipe and the lower drain pipe is not less than 10cm, and the interval between each set of drain pipes is not less than 1.5 meters.

[0005] Furthermore, the timber stacks are at least two groups.

[0006] Furthermore, the timber stacks are made of timber of the same specifications, erected in a "well" shape, and secured at the four corners with wedges.

[0007] Furthermore, the filter screen is at least 500mm high, with its four sides fixed with iron corners, and the aperture is no more than 3mm.

[0008] Furthermore, each drain pipe is equipped with two sets of shut-off valves.

[0009] Furthermore, the backwash device is located after the first set of shut-off valves.

[0010] Furthermore, the diameter of the inlet of the backflushing device is the same as the diameter of the drain pipe, and the diameter of the outlet is smaller than that of the inlet.

[0011] Furthermore, the diameter of the outlet of the backwash device is one-third of the diameter of the inlet.

[0012] Furthermore, the submersible pump is a high-lift multistage pump.

[0013] The beneficial effects of this invention are: a drainage system behind the goaf in a coal mine, with wooden stacks installed in front of the waterproof wall to protect the roof of the connecting roadway, the waterproof wall, and the drainage pipe; a filter screen installed behind the wooden stacks to prevent large pieces of gangue and coal from entering the drainage pipe and clogging it; and a backwashing device to clean up the settled gravel, silt, and coal slag under high pressure and discharge them into the pipe, which is safe and fast. This system solves the problems of abundant debris and gangue in the goaf, the lack of support and protection at the closed connecting roadway, the risk of roof collapse, pipe breakage, or pipe blockage, resulting in poor drainage and affecting water supply.

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] Figure 1 This is a planar schematic diagram of the present invention;

[0016] Figure 2 Schematic diagram of the AA cross-section of the present invention;

[0017] Figure 3 Schematic diagram of the BB cross-section of the present invention;

[0018] Figure 4 Top view of the timber stack of this invention;

[0019] Figure 5 A schematic diagram of the backwashing device of the present invention. Detailed Implementation

[0020] Example 1: Figures 1 to 5 As shown, a coal mine goaf drainage system includes a waterproof wall 1, drainage pipes 2, connecting roadways 3, and drainage tunnels 4. The system is characterized by further including timber stacks 5, a filter screen 6, a high-pressure submersible pump 7, a sump pit 8, a shut-off valve 9, and a backflushing device 10. Two sets of timber stacks 5 are located at the entrance of the waterproof wall 1. The filter screen 6, with a size consistent with the width of the connecting roadway 3, is located behind the timber stacks 5. At least two drainage pipes 2 are staggered within the waterproof wall 1, each with a shut-off valve 9 at its outlet. The high-pressure submersible pump 7 is located within the sump pit 8 and connected to the outlet of the drainage pipe 2. The backflushing device is located between the shut-off valve and the high-pressure submersible pump.

[0021] Example 2: Based on the above-mentioned coal mine goaf drainage system, the lower drainage pipe is 20cm away from the bottom plate, the height difference between the upper drainage pipe and the lower drainage pipe is not less than 10cm, and the interval is not less than 1.5 meters.

[0022] Example 3: Based on Examples 1-2, the diameter of the drain pipe is 300 mm.

[0023] Example 4: Figure 3 , Figure 4 As shown, based on the above embodiment, the timber stack uses square-section timber of the same specifications, and is erected in a "well" shape. The timber is 1.2 meters long, 0.2 meters wide, and 0.2 meters thick. It is erected layer by layer from bottom to top, keeping the whole stack straight. The four corners must be aligned and fixed with wedges. The erection process and method are as follows: First, determine the position of the timber stack and clear the stack area. Then, place the first layer along the direction of the connecting alley, place the second layer perpendicular to the first layer, and so on, alternating until it contacts the top plate. After the timber stack is erected, the adjacent two layers of timber are fixed with rake nails 501.

[0024] Example 5: Figures 1 to 3 As shown, based on the above embodiment, the filter screen is at least 500mm high. For structural stability, the filter screen is fixed with iron angle 601 around its perimeter, and the filter screen has a pore size of 3mm.

[0025] Example 6: As Figure 1 , Figure 2 As shown, based on the above embodiment, each drain pipe outlet is equipped with two sets of shut-off valves.

[0026] Example 7: During the use of the drain pipe, some mud, sand and small gravel will gradually accumulate inside the pipe, affecting the drainage effect. When performing backflushing operation, based on Examples 1 to 6, this invention removes the second set of shut-off valves at the outlet of the drain pipe and temporarily closes the first set of shut-off valves. The backflushing device is installed after the first set of shut-off valves, and the reverse water flow is achieved through a high-pressure submersible pump.

[0027] Example 8: As Figure 5 As shown, based on the above embodiment, the backwash device is connected to the outlet pipe of the drain pipe. The inlet diameter is the same as that of the drain pipe, and the outlet diameter is smaller than that of the inlet. The backwash device is bolted to the drain pipe through flange 11.

[0028] Example 9: Further, the diameter of the outlet of the backwash device is one-third of the diameter of the inlet.

[0029] Example 10: Further, when the water volume in the goaf is large and the drainage capacity of the submersible pump is insufficient, a high-head multistage pump is used.

Claims

1. A drainage system for the goaf of a coal mine, comprising a waterproof wall, a drainage pipe, a connecting roadway, and a drainage roadway, characterized in that, It also includes timber stacks, filter screens, high-lift multistage pumps, shut-off valves, backwash devices, and sump pits. The timber stacks are located at the entrance to the waterproof wall, with two sets arranged in a "well" shape, secured at the four corners by wedges. The timber dimensions are 1.2 meters long, 0.2 meters wide, and 0.2 meters thick. The first layer is stacked along the direction of the connecting lane, the second layer is stacked perpendicular to the first layer, and so on, alternating until it contacts the roof. After the timber stacks are stacked, adjacent layers are secured with rake nails (501). The filter screen is the same size as the width of the connecting lane, at least 500 mm high, with a aperture no larger than 3 mm, and is located behind the timber stacks. The drainage pipes are provided in sets of at least two pipes, one high and one low. The lower pipe is at least 20 cm from the bottom of the lane, and the higher pipe... The height difference between the drain pipe and the low-pressure pipe shall not be less than 10cm, the interval between each set of drain pipes shall not be less than 1.5 meters, the pipe diameter shall be 300 mm, and the drain pipe shall be installed inside the waterproof wall. Each drain pipe shall be equipped with two sets of shut-off valves at its outlet. The high-lift multistage pump shall be installed in the sump and connected to the drain pipe. The backwash device shall be installed between the shut-off valve and the high-lift multistage pump. The inlet diameter of the backwash device shall be the same as the drain pipe diameter, and the outlet diameter shall be one-third of the inlet diameter. When performing backwash operation, the second set of shut-off valves shall be removed at the outlet of the drain pipe, and the first set of shut-off valves shall be temporarily closed. The backwash device shall be installed after the first set of shut-off valves, and the reverse water flow shall be achieved through the high-lift multistage pump.

2. The coal mine goaf drainage system according to claim 1, characterized in that, The backwash device is located after the first set of shut-off valves.

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