Water jet mining device suitable for physical fluidization mining

Abstract

This utility model discloses a water jet mining device suitable for physical fluidized bed mining, including a mechanical extension arm coal breaking unit, a high-low pressure water circuit control conversion unit, and a positioning and reset unit. The mechanical extension arm coal breaking unit includes a jet support body, a hollow shaft, and a mechanical extension arm. The high-low pressure water circuit control conversion unit includes a high-low pressure conversion valve core, a control spring, and a seal, all coaxially installed within the jet support body. The positioning and reset unit includes a reset torsion spring and a drill pipe connection joint. This water jet mining device suitable for physical fluidized bed mining is small in size, highly mobile, and flexible. Utilizing the mechanical extension arm for borehole enlargement can effectively increase the coal breaking volume and gas extraction concentration per borehole, enabling safe and efficient underground co-mining of coal and gas using fluidized bed technology. It is particularly suitable for coal and gas mining operations in gas-bearing mines.

Description

Technical Field

[0001] This utility model relates to a water jet mining device, specifically a water jet mining device suitable for physical fluidization mining, belonging to the field of coal mining technology. Background Technology

[0002] Currently, apart from a small amount of open-pit mining, over 90% of coal mines in my country use traditional underground mining methods. However, when mining coal and gas outburst-prone seams using underground methods, these methods suffer from drawbacks such as high economic costs, low disaster management efficiency, and significant safety risks. The current coal recovery rate using underground mining is only 30%–40%. Inevitably, some marginal blocks and small coal pillars (commonly known as "corner coal") remain in the mining area. Due to the significant variations in shape and thickness of corner coal, large-scale fully mechanized mining equipment is unsuitable for mining corner coal. Furthermore, the mining conditions for corner coal are usually complex, such as high mining pressure and roof fracturing, making it difficult to mine and often leading to its abandonment. On the other hand, for discontinuous, clustered coal resources (commonly known as "chicken coop coal"), the discontinuous nature and low content of these resources make underground mining extremely cost-effective, often resulting in their abandonment due to lack of mining value. However, abandoning the mining of corner coal and chicken coop coal, which have low coal content and complex geological conditions, leads to a waste of coal resources.

[0003] Existing technologies, such as hydraulic drilling, are one way to address the aforementioned problems. Hydraulic drilling utilizes high-pressure water generated by a high-pressure water pump to impact the coal surface, causing it to break up and thus achieving the purpose of mining. However, hydraulic drilling and similar measures can damage the integrity of the coal seam, altering the stress field in the exposed area, reducing coal strength, and preserving the risk of coal and gas outbursts. Even with pressure relief and permeability enhancement measures, the time required for gas extraction remains very long, especially in high-gas-outburst mines, where extraction can take more than a year, severely impacting and restricting the overall production progress of coal mining. Summary of the Invention

[0004] To address the problems existing in the prior art, this utility model provides a water jet mining device suitable for physical fluidized mining, which can effectively increase the coal breaking capacity and gas extraction concentration per hole, and can realize safe and efficient underground coal and gas fluidized co-mining, and is particularly suitable for coal and gas mining operations in gas-bearing mines.

[0005] To achieve the above objectives, this water jet mining device suitable for physical fluidized mining includes a mechanical extension arm coal breaking unit, a high and low pressure water circuit control and conversion unit, and a positioning and resetting unit.

[0006] The mechanical extension arm coal breaking unit includes a jet support body, a hollow shaft, and a mechanical extension arm. The jet support body has a main hollow water passage arranged in the front-to-back direction, a low-pressure water passage at the front end, and a high-pressure water passage at the rear end. The mechanical extension arm has a secondary hollow water passage arranged along its length. The mechanical extension arm is hinged to the jet support body via the hollow shaft. The hollow shaft has a water inlet that passes through it in the radial direction, and the main hollow water passage and the secondary hollow water passage are connected through the water inlet of the hollow shaft. The mechanical extension arm also has a jet outlet that is connected to the secondary hollow water passage. The central axis of the secondary hollow water passage is located in the tangential direction of the hollow shaft.

[0007] The high-low pressure water circuit control conversion unit is located at the front end of the main hollow water passage. It includes a high-low pressure conversion valve core, a control spring, and a seal, which are coaxially installed in the jet support body. The high-low pressure conversion valve core has a blind hole structure at the end facing the main hollow water passage, and a low-pressure water outlet that penetrates the high-low pressure conversion valve core in a radial direction is located at the bottom of the blind hole structure. When no pressurized water is injected into the main hollow water passage, the low-pressure water outlet of the high-low pressure conversion valve core is misaligned and blocked from the low-pressure water passage. When low-pressure water is injected into the main hollow water passage, the low-pressure water outlet of the high-low pressure conversion valve core is aligned and connected to the low-pressure water passage. When high-pressure water is injected into the main hollow water passage, the low-pressure water outlet of the high-low pressure conversion valve core is misaligned and blocked from the low-pressure water passage.

[0008] The positioning and resetting unit includes a reset torsion spring and a drill rod connecting joint. The reset torsion spring is sleeved on the hollow shaft, and the drill rod connecting joint is fixedly located at the rear end of the jet support body.

[0009] As a further improvement of this utility model, the positioning and resetting unit also includes a positioning buckle, which is fixedly installed on the jet support body. When the mechanical extension arm is in the retracted state, the positioning buckle is engaged with the mechanical extension arm.

[0010] As a further improvement of this utility model, a hard alloy patch is fixedly provided on the outside of the mechanical extension arm.

[0011] As a further improvement of this utility model, the secondary hollow water passage is a tapered channel structure that gradually narrows along the jetting direction.

[0012] As a further improvement of this utility model, the jet outlet and the secondary hollow water passage are coaxially arranged.

[0013] Compared with existing technologies, when this water jet mining device, suitable for physical fluidized bed mining, is installed at the front of the hollow drill pipe, before the jet coal breaking operation, the mechanical extension arm is retracted into the jet support body. The extension of the mechanical extension arm is controlled by the water pressure. When low pressure is injected into the main hollow water passage, the low pressure water outlet of the high-low pressure conversion valve core is in a positive connection state with the low pressure water passage, which can realize the low pressure water jet cleaning the drill bit and cooling the drill bit through the low pressure water passage. When high pressure water is injected into the main hollow water passage, the mechanical extension arm can rotate and extend outward within the range of 0 to 90° around the hollow shaft. After the jet coal breaking operation, the water pressure is reduced, and the mechanical extension arm is retracted into the jet support body in the opposite direction of the extension. This water jet mining device, based on the physical fluidization of coal and gas, eliminates the need for longwall mining faces and large machinery. Its small size, high mobility, and flexibility allow for increased single-hole mining range through the use of a mechanical extension arm, improving mining efficiency and reducing costs. It enables safe and efficient mining of difficult-to-mine (or abandoned) coal resources, including edge coal, nested coal seams, geologically complex seams, thin seams, steeply inclined seams, and abandoned coal pillars. Furthermore, the jet breaking of the coal body allows for complete desorption and release of gas. The mechanical extension arm further increases the gas extraction volume and concentration per hole, allowing for direct use in gas generator sets. Gas and dust are not directly discharged into roadways or chambers, and operators are kept away from the coal-breaking area, resulting in a better working environment and safety, and enabling efficient development and utilization of gas resources. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the mechanical extension arm of this utility model in its fully extended state.

[0015] Figure 2 This is a cross-sectional view of the present invention;

[0016] Figure 3 This is a three-dimensional structural schematic diagram of the mechanical extension arm of this utility model;

[0017] Figure 4 This is a cross-sectional view of the mechanical extension arm of this utility model;

[0018] Figure 5 This is a three-dimensional structural schematic diagram of the high-low pressure switching valve core of this utility model;

[0019] Figure 6 This is a cross-sectional view of the high-low pressure switching valve core of this utility model.

[0020] In the diagram: 1. Mechanical extension arm coal breaking unit; 1-1. Jet support main body; 1-2. Hollow shaft; 1-3 Mechanical extension arm; 2. High and low pressure water circuit control conversion unit; 2-1. High and low pressure conversion valve core; 2-2. Control spring; 2-3. Seal; 3. Positioning and reset unit; 3-1. Positioning buckle; 3-2. Reset torsion spring; 3-3. Drill rod connection joint. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings (hereinafter referred to as...). Figure 1 , Figure 2 (The right-hand direction is described as the front).

[0022] like Figure 1 , Figure 2 As shown, this water jet mining device suitable for physical fluidized bed mining includes a mechanical extension arm coal breaking unit 1, a high and low pressure water circuit control conversion unit 2, and a positioning and reset unit 3.

[0023] The mechanical extension arm coal breaking unit 1 includes a jet support body 1-1, a hollow shaft 1-2, and a mechanical extension arm 1-3. The jet support body 1-1 has a main hollow water passage arranged in the front-to-back direction. The front end of the jet support body 1-1 has a low-pressure water passage for cleaning the drill bit, and the rear end of the jet support body 1-1 has a high-pressure water passage for connecting the hollow drill rod. The mechanical extension arm 1-3 has a secondary hollow water passage arranged along its length. The mechanical extension arm 1-3 is hinged to the jet support body 1-1 via the hollow shaft 1-2. The hollow shaft 1-2 has a water inlet that penetrates the hollow shaft 1-2 in the radial direction, and the main hollow water passage and the secondary hollow water passage are connected through the water inlet of the hollow shaft 1-2. The mechanical extension arm 1-3 also has a jet outlet that communicates with the secondary hollow water passage, and the jet outlet can be coaxially arranged with the secondary hollow water passage. Figure 3 , Figure 4 As shown, the central axis of the secondary hollow water passage is located in the tangential direction of the hollow shaft 1-2. When high-pressure water enters the secondary hollow water passage through the water inlet of the hollow shaft 1-2, it can provide the swinging power for the mechanical extension arm 1-3 to swing, so that the mechanical extension arm 1-3 can rotate and extend outward around the axis of the hollow shaft 1-2 in the range of 0 to 90°.

[0024] The high-low pressure water circuit control conversion unit 2 is located at the front end of the main hollow water passage, and includes a high-low pressure conversion valve core 2-1, a control spring 2-2, and a seal 2-3, which are coaxially installed in sequence within the jet support body 1-1. Figure 5 , Figure 6As shown, the high-low pressure switching valve core 2-1 has a blind hole structure at one end facing the main hollow water passage, and a low-pressure water outlet is provided at the bottom of the blind hole structure, which penetrates the high-low pressure switching valve core 2-1 in a radial direction. When no pressurized water is injected into the main hollow water passage, the high-low pressure switching valve core 2-1, under the elastic force of the control spring 2-2, makes the low-pressure water outlet and the low-pressure water passage in a misaligned and blocked state. When low-pressure water is injected into the main hollow water passage, the low-pressure water can push the high-low pressure switching valve core 2-1 to overcome the elastic force of the control spring 2-2 and make the low-pressure water outlet and the low-pressure water passage in a aligned and connected state. When high-pressure water is injected into the main hollow water passage, the high-pressure water can push the high-low pressure switching valve core 2-1 to compress the control spring 2-2 and make the low-pressure water outlet and the low-pressure water passage in a misaligned and blocked state.

[0025] The positioning and resetting unit 3 includes a positioning buckle 3-1, a resetting torsion spring 3-2, and a drill rod connecting joint 3-3. The positioning buckle 3-1 is fixedly installed on the jet support body 1-1. When the mechanical extension arm 1-3 is in the retracted state, the positioning buckle 3-1 can be engaged with the mechanical extension arm 1-3 to position the mechanical extension arm 1-3 inside the jet support body 1-1. The resetting torsion spring 3-2 is sleeved on the hollow shaft 1-2. Its main function is to provide restoring force so that the mechanical extension arm 1-3 retracts inward from the extended state to the retracted state after the operation is completed. The drill rod connecting joint 3-3 is fixedly installed at the rear end of the jet support body 1-1 and is used to connect the hollow drill rod.

[0026] To increase the wear resistance of the mechanical extension arms 1-3, as a further improvement to this utility model, such as... Figure 3 , Figure 4 As shown, a hard alloy patch can be fixedly installed on the outside of the mechanical extension arm 1-3.

[0027] To achieve a better diameter expansion effect, as a further improvement of this utility model, the secondary hollow water passage is a tapered channel structure that gradually narrows along the jet direction.

[0028] When this water jet mining device, suitable for physical fluidized bed mining, is installed at the front of the hollow drill pipe, before the jet coal breaking operation, the mechanical extension arm 1-3 is housed inside the jet support body 1-1. The extension of the mechanical extension arm 1-3 is controlled by the water pressure. When the pressure water injected into the main hollow water passage reaches 5MPa, the low-pressure water outlet of the high-low pressure conversion valve core 2-1 is aligned with the low-pressure water passage, allowing the low-pressure water jet to clean the drill bit and cool it down. When the pressure water injected into the main hollow water passage reaches 10-30MPa, the mechanical extension arm 1-3 can rotate outward within a range of 0-90° around the hollow shaft 1-2. After the jet coal breaking operation, the water pressure decreases, and the mechanical extension arm 1-3 is retracted into the jet support body 1-1 in the opposite direction of its extension. This water jet mining device, based on the physical fluidization of coal and gas, eliminates the need for longwall mining faces and large machinery. Its small size, high mobility, and flexibility allow for increased single-hole mining range through the use of mechanical extension arms 1-3, improving mining efficiency and reducing costs. It enables safe and efficient mining of difficult-to-mine (or abandoned) coal resources, including edge coal, nested coal seams, geologically complex coal seams, thin coal seams, steeply inclined coal seams, and abandoned coal pillars. Furthermore, the jet breaking of the coal body allows for complete desorption and release of gas. The increased gas extraction volume and concentration per hole through the mechanical extension arms 1-3 allows for direct use in gas generator sets. Gas and dust are not directly discharged into roadways or chambers, and operators are kept away from the coal breaking area, resulting in a better working environment and safety, and enabling efficient development and utilization of gas resources.

Claims

1. A water jet mining device suitable for physical fluidization mining, characterized in that, It includes a mechanical extension arm coal breaking unit (1), a high and low pressure water circuit control conversion unit (2), and a positioning and reset unit (3); The mechanical extension arm coal breaking unit (1) includes a jet support body (1-1), a hollow shaft (1-2), and a mechanical extension arm (1-3); the jet support body (1-1) has a main hollow water passage arranged in the front-to-back direction, a low-pressure water passage at the front end of the jet support body (1-1), and a high-pressure water passage at the rear end of the jet support body (1-1); the mechanical extension arm (1-3) has a secondary hollow water passage arranged along its length direction. The arm (1-3) is hinged to the jet support body (1-1) via the hollow shaft (1-2). The hollow shaft (1-2) is provided with a water inlet that passes through the hollow shaft (1-2) in the radial direction. The main hollow water inlet channel and the secondary hollow water inlet channel are connected through the water inlet of the hollow shaft (1-2). The mechanical extension arm (1-3) is also provided with a jet outlet that is connected to the secondary hollow water inlet channel. The central axis of the secondary hollow water inlet channel is located in the tangential direction of the hollow shaft (1-2). The high-low pressure water circuit control conversion unit (2) is located at the front end of the main hollow water passage, including a high-low pressure conversion valve core (2-1), a control spring (2-2), and a seal (2-3) which are coaxially installed in the jet support body (1-1). The high-low pressure conversion valve core (2-1) has a blind hole structure at one end facing the main hollow water passage, and a low-pressure water circuit outlet that penetrates the high-low pressure conversion valve core (2-1) in the radial direction is located at the bottom of the blind hole structure. When no pressurized water is injected into the main hollow water passage, the low-pressure water outlet of the high-low pressure switching valve core (2-1) and the low-pressure water passage are misaligned and blocked. When low-pressure water is injected into the main hollow water passage, the low-pressure water outlet of the high-low pressure switching valve core (2-1) and the low-pressure water passage are aligned and connected. When high-pressure water is injected into the main hollow water passage, the low-pressure water outlet of the high-low pressure switching valve core (2-1) and the low-pressure water passage are misaligned and blocked. The positioning and reset unit (3) includes a reset torsion spring (3-2) and a drill rod connecting joint (3-3). The reset torsion spring (3-2) is sleeved and connected to the hollow shaft (1-2), and the drill rod connecting joint (3-3) is fixedly located at the rear end of the jet support body (1-1).

2. The water jet mining apparatus for physical fluidization mining according to claim 1, characterized in that, The positioning and reset unit (3) also includes a positioning buckle (3-1), which is fixedly installed on the jet support body (1-1). When the mechanical extension arm (1-3) is in the retracted state, the positioning buckle (3-1) is engaged with the mechanical extension arm (1-3).

3. The water jet mining apparatus for physical fluidization mining according to claim 1, characterized in that, The mechanical extension arm (1-3) is externally fixed with a hard alloy patch.

4. The water jet mining apparatus for physical fluidization mining according to claim 1, characterized in that, The secondary hollow water passage is a cone-shaped channel structure that gradually narrows along the jet direction.

5. The water jet mining apparatus for physical fluidization mining according to claim 1, characterized in that, The jet outlet and the secondary hollow water passage are coaxially arranged.

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