Negative-pressure coal body drilling cutting extraction device
By designing a negative pressure extraction device for coal cuttings, a centrifugal fan is used to generate negative pressure suction, which solves the problem of difficult extraction of drilling cuttings in moist coal, and achieves efficient collection of coal cuttings and improved monitoring accuracy.
Patent Information
- Application Number
- CN202520712855.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-04-16
AI Technical Summary
In moist coal seams, existing drill cuttings methods are difficult to effectively collect drill cuttings, resulting in low monitoring accuracy and significant drill cuttings loss, making it impossible to effectively monitor the risk of rockbursts in coal mines.
Design a negative pressure coal cuttings extraction device, including a drill rod set, connector, drill rig and cuttings collection device. It uses a centrifugal fan to generate negative pressure to extract coal cuttings, and achieves efficient collection of coal cuttings through helical blades and a detachable drill rod structure.
This method improves the efficiency of drill cuttings collection in wet coal seams, reduces drill cuttings loss, and enhances the applicability and monitoring accuracy of the drill cuttings method in wet coal seams.
Smart Images
Figure CN223781415U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a negative pressure extraction device for coal cuttings, belonging to the field of coal mining and coal mine safety technology. Background Technology
[0002] The drill cuttings method is a popular method for monitoring rockburst hazards in coal mines. It is characterized by its simplicity and high accuracy, and is widely used in this field. The method involves drilling a hole in the coal seam using a coal drill bit, followed by the rotation of a twist drill rod to remove drill cuttings. However, when the coal has a high moisture content, the coal particles tend to coat the drill rod, making it difficult to remove the cuttings and hindering effective monitoring of the rockburst hazard in moist coal. Furthermore, mining operations create numerous fissures in the surrounding coal and rock mass, allowing water from aquifers to seep into the coal, increasing its moisture content. High-pressure water injection to soften the coal and mitigate rockburst further exacerbates this problem, often rendering the drill cuttings monitoring method ineffective. Additionally, using a twist drill rod results in significant cuttings loss and low accuracy. Summary of the Invention
[0003] To address the problems existing in the prior art, this utility model provides a negative pressure extraction device for coal cuttings. This device can effectively solve the problems of ineffective collection of drill cuttings from damp coal and leakage of coal cuttings, thereby improving the applicability and scope of the drill cuttings method.
[0004] To achieve the above-mentioned objectives, this utility model provides...
[0005] A negative pressure coal cuttings extraction device includes a drill rod set, a connector, a drilling rig, and a cuttings collection device;
[0006] The drill rod assembly includes a drill bit and multiple hollow drill rods; planar helical blades are wound around the outer circumference of the hollow drill rods along their axial direction, and adjacent hollow drill rods are connected by threaded interfaces;
[0007] The connector includes a rectangular hollow body, a connecting center, and a sealed bearing. The outer surface of the rectangular hollow body is rectangular, and the hollow part is cylindrical. A cylindrical hole is opened on one side of the rectangular hollow body, and a cylindrical brim extends outward from the outside of the hole. The chip collection device communicates with the hole through the brim. The connecting center is embedded in the hollow cylinder, and its upper and lower ends are connected to the drill rod set and the drilling rig, respectively. The middle of the connecting center is a cylindrical hollow body with multiple cylindrical holes on its surface. One end of the cylindrical hollow body faces the rectangular hollow body, and the other end communicates with the hole. A sealed bearing is used to connect the connecting center and the rectangular hollow body.
[0008] The chip collection device includes a chip recovery pipe, a filter, a chip collector, and a centrifugal fan; one end of the chip recovery pipe is connected to the chip outlet end of the hole, the other end of the chip recovery pipe is connected to one end of the filter, the other end of the filter is connected to the centrifugal fan, and the lower end of the filter is connected to the chip collector.
[0009] Furthermore, the drill bit consists of four blades located around the perimeter, with a hole in the center. The drill bit and drill rod are connected by a threaded interface for detachable connection. The outer diameter of the drill bit is 42mm, and the hole diameter is not less than 20mm.
[0010] Furthermore, the adjacent hollow drill rods are connected by threaded interfaces, and the interfaces are sealed; the planar helical blades are welded onto the hollow drill rods.
[0011] Furthermore, both sides of the connecting center are connected to the drilling rig and the hollow drill rod through threaded interfaces, and the axes of the drilling rig and the hollow drill rod are on a straight line; there is a gap between the cylindrical hollow body and the rectangular hollow body to ensure the free rotation of the cylindrical hollow body; the cylindrical holes on the surface of the cylindrical hollow body are evenly distributed, and the axes of the cylindrical holes of the cylindrical hollow body and the rectangular hollow body are on the same line; the cylindrical hollow body and the holes are connected.
[0012] Furthermore, the centrifugal fan features stepless speed regulation.
[0013] Furthermore, the filter mesh diameter is determined according to the size of the crushed coal particles to ensure that it can filter out coal dust while ensuring sufficient air permeability.
[0014] Furthermore, the cuttings recovery pipe is a retractable hose, the inner diameter of which is adapted to the outer diameter of the cylindrical cap of the rectangular hollow body.
[0015] Furthermore, the drill bit, hollow drill rod, connector, drilling rig, filter, chip collector, and centrifugal fan are all detachable connections.
[0016] This utility model also provides a method for negative pressure extraction of drill cuttings from coal seams, specifically as follows:
[0017] 1) Determine the drilling depth and inclination angle of the cuttings holes based on data such as coal seam thickness, roadway height, coal seam dip angle, and coal pillar width.
[0018] 2) First, use a one-meter-long drill rod, with the drill bit and connector at each end respectively. The connector is then connected to the drill rig and the cuttings collector respectively.
[0019] 3) The drilling rig drives the drill rod and drill bit to drill into and cut the coal body to form a borehole. At the same time, the centrifugal fan is started to suck up the crushed coal powder. The coal powder is collected in the chip collector through the drill bit, drill rod and connector. After the first meter of drill rod is completed, the coal powder in the chip collector is weighed and recorded.
[0020] 4) After each meter is completed, add a drill rod and weigh the coal powder. Repeat this process until the borehole reaches the designed depth.
[0021] 5) The method further includes: when an impact occurs inside the hole, the coal powder is discharged by the rotation of the spiral blades on the outside of the drill rod, and the drill rod is continuously withdrawn to avoid the drill rod being stuck or lost.
[0022] This invention comprises a drill rod assembly, a connector, a drill rig, and a cuttings collection device. The connector connects the drill rig, drill rod, and centrifugal fan. A freely rotatable cylindrical hollow body is housed within the connector, with multiple circular through holes. When drilling and breaking coal, the drill rig rotates, and coal debris at the drill bit is drawn into the hollow drill rod by the negative pressure of the centrifugal fan. The debris is then collected in the cuttings collection device through the holes in the cylindrical hollow body and the connector. The centrifugal fan's suction action effectively collects the broken coal debris, solving the problem of damp coal debris that cannot be recovered with twisted drill rods. This device has a simple structure, is easy to operate, and has a wide range of applications. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structure of this utility model;
[0024] Figure 2 This is a schematic diagram of the drill bit design of this utility model;
[0025] Figure 3 This is a schematic cross-sectional view of the drill pipe of this utility model;
[0026] Figure 4 This is a cross-sectional view of the connector of this utility model. Figure 1 ;
[0027] Figure 5 This is a cross-sectional view of the connector of this utility model. Figure 2 .
[0028] In the diagram: 1. Drill rod assembly; 101. Drill bit; 102. Hollow drill rod; 103. Planar helical blade; 104. Threaded interface; 2. Connector; 21. Rectangular hollow body; 211. Hole; 212. Cap; 22. Connecting center; 221. Cylindrical hollow body; 222. Cylindrical hole; 23. Sealed bearing; 3. Drilling rig; 4. Chip collection device; 401. Chip recovery pipe; 402. Filter; 403. Chip collector; 404. Centrifugal fan. Detailed Implementation
[0029] The embodiments of this utility model will be further described below with reference to the accompanying drawings.
[0030] like Figures 1 to 5 As shown, a negative pressure coal cuttings extraction device includes a drill rod set 1, a connector 2, a drill rig 3, and a cuttings collection device 4;
[0031] The drill rod assembly 1 includes a drill bit 101 and multiple hollow drill rods 102; a planar helical blade 103 is wound around the outer circumference of the hollow drill rod 102 along its axial direction, and adjacent hollow drill rods 102 are connected by a threaded interface 104.
[0032] The connector 2 includes a rectangular hollow body 21, a connecting center 22, and a sealed bearing 23. The outer surface of the rectangular hollow body 21 is rectangular, and the hollow part is cylindrical. A cylindrical hole 211 is opened on one side of the rectangular hollow body 21, and a cylindrical brim 212 extends outward from the outside of the hole 211. The chip collection device 4 communicates with the hole 211 through the brim 212. The connecting center 22 is embedded in the hollow cylinder, and its upper and lower ends are connected to the drill rod set 1 and the drilling machine 3, respectively. The middle of the connecting center 22 is a cylindrical hollow body 221 with multiple cylindrical holes 222 on its surface. One end of the cylindrical hollow body 221 faces the rectangular hollow body 21, and the other end communicates with the hole 211. The connecting center 22 and the rectangular hollow body 21 are connected by a sealed bearing 23.
[0033] The chip collection device 4 includes a chip recovery pipe 401, a filter 402, a chip collector 403, and a centrifugal fan 404; one end of the chip recovery pipe 401 is connected to the chip outlet end of the hole 211, the other end of the chip recovery pipe 401 is connected to one end of the filter 402, the other end of the filter 402 is connected to the centrifugal fan 404, and the lower end of the filter 402 is connected to the chip collector 403.
[0034] In one preferred embodiment, the drill bit 101 consists of four blades located around the perimeter, with a hole in the center of the drill bit. The drill bit and the drill rod are connected by a threaded interface, allowing for detachable connection.
[0035] In a preferred embodiment, adjacent hollow drill rods 102 are connected by threaded interfaces, and the interfaces are sealed; the planar helical blades 103 are welded onto the hollow drill rods 102.
[0036] In a preferred embodiment, both sides of the connecting center 22 are connected to the drilling rig 3 and the hollow drill rod 102 via threaded interfaces, and the axes of the drilling rig 3 and the hollow drill rod 102 are on a straight line; a gap is provided between the cylindrical hollow body 221 and the rectangular hollow body 21; cylindrical holes 222 are evenly distributed on the surface of the cylindrical hollow body 221, and the axes of the cylindrical hollow body 221 and the cylindrical holes 211 of the rectangular hollow body 21 are on the same line; the cylindrical hollow body 221 and the holes 211 are connected.
[0037] As a preferred embodiment, the centrifugal fan 404 is infinitely variable in speed.
[0038] In a preferred embodiment, the drill cuttings recovery pipe 401 is a retractable hose whose inner diameter is adapted to the outer diameter of the cylindrical cap 212 of the rectangular hollow body 21.
[0039] In a preferred embodiment, the drill bit 101, hollow drill rod 102, connector 2, drilling rig 3, filter 402, chip collector 403, and centrifugal fan 404 are all detachably connected.
[0040] In use, the drill bit 101 is connected to the hollow drill rod 102 to form the drill rod assembly 1. A sealed bearing 23 is first installed on one side of the connecting center 22, which is then inserted into the rectangular hollow body 21. The other sealed bearing 23 is then installed, forming the connector 2. Both ends of the connecting center 22 are connected to the drill rod assembly 1 and the drilling rig 3, respectively. The cylindrical cap 212, the cuttings recovery pipe 401, the filter 402, the cuttings collector 403, and the centrifugal fan 404 are connected in sequence. This assembles a negative pressure coal seam cuttings extraction device.
[0041] The drilling rig starts, causing the connector, drill rod, and drill bit to rotate. The blades at the front of the drill bit cut and break up the coal. Under the negative pressure suction generated by the centrifugal fan, the coal debris enters the hollow drill rod through the hole in the middle of the drill bit, passes through the connector, and collects in the main drill cuttings recovery pipe, settling into the cuttings collection device. The drill rod and drill bit move forward continuously under the thrust of the drilling rig, making close contact with the coal wall and cutting forward. When the forward distance reaches 1m, drilling is stopped, the drill rod is added, and the weight of the drill cuttings within 1m is weighed. This cycle is repeated until the designed drilling depth is reached. In cases of dynamic disasters such as coal blasting, where the borehole wall collapses and crushes the drill rod, the collapsed coal dust is continuously discharged through the external threads of the drill rod. This portion of coal dust is not weighed. After completing the drill cuttings monitoring, the drill rod is pulled out by the backward force of the drilling rig, and the coal dust on the borehole wall is discharged by the external threads of the drill rod until the drill rod is completely removed.
Claims
1. A negative pressure extraction device for coal cuttings, characterized in that, Includes drill pipe assembly (1), connector (2), drilling rig (3), and chip collection device (4); The drill rod assembly (1) includes a drill bit (101) and multiple hollow drill rods (102); the outer circumference of the hollow drill rod (102) is wound with a planar helical blade (103) along its axial direction, and adjacent hollow drill rods (102) are connected by a threaded interface (104); The connector (2) includes a rectangular hollow body (21), a connecting center (22), and a sealed bearing (23); the outer surface of the rectangular hollow body (21) is rectangular, and the hollow part is cylindrical; a cylindrical hole (211) is provided on one side of the rectangular hollow body (21), and a cylindrical brim (212) extends outward from the outside of the hole (211); the chip collection device (4) communicates with the hole (211) through the brim (212); The connecting center (22) is embedded in the hollow cylinder, and its upper and lower ends are connected to the drill rod set (1) and the drilling machine (3) respectively. The middle of the connecting center (22) is a cylindrical hollow body (221) with multiple cylindrical holes (222) on its surface. One end of the cylindrical hollow body (221) faces the rectangular hollow body (21), and the other end is connected to the hole (211). The connecting center (22) and the rectangular hollow body (21) are connected by a sealed bearing (23). The chip collection device (4) includes a chip recovery pipe (401), a filter (402), a chip collector (403), and a centrifugal fan (404); one end of the chip recovery pipe (401) is connected to the chip outlet end of the hole (211), the other end of the chip recovery pipe (401) is connected to one end of the filter (402), the other end of the filter (402) is connected to the centrifugal fan (404), and the lower end of the filter (402) is connected to the chip collector (403).
2. The negative pressure coal cuttings extraction device according to claim 1, characterized in that, The drill bit (101) consists of four blades located around the perimeter, with a hole in the center. The drill bit and the drill rod are connected by a threaded interface and can be detached.
3. The negative pressure coal cuttings extraction device according to claim 1, characterized in that, The adjacent hollow drill rods (102) are connected by threaded interfaces and the interfaces are sealed; the planar helical blades (103) are welded onto the hollow drill rods (102).
4. The negative pressure coal cuttings extraction device according to claim 1, characterized in that, Both sides of the connecting center (22) are connected to the drilling machine (3) and the hollow drill rod (102) through threaded interfaces. The axes of the drilling machine (3) and the hollow drill rod (102) are on a straight line. There is a gap between the cylindrical hollow body (221) and the rectangular hollow body (21). The cylindrical holes (222) on the surface of the cylindrical hollow body (221) are evenly distributed, and the axes of the cylindrical hollow body (221) and the cylindrical holes (211) of the rectangular hollow body (211) are on the same line. The cylindrical hollow body (221) and the hole (211) are connected.
5. The negative pressure coal cuttings extraction device according to claim 1, characterized in that, The centrifugal fan (404) is infinitely variable in speed.
6. The negative pressure coal cuttings extraction device according to claim 1, characterized in that, The cuttings recovery pipe (401) is a retractable hose whose inner diameter is adapted to the outer diameter of the cylindrical cap (212) of the rectangular hollow body (21).
7. The negative pressure coal cuttings extraction device according to claim 1, characterized in that, The drill bit (101), hollow drill rod (102), connector (2), drilling rig (3), filter (402), chip collector (403), and centrifugal fan (404) are all detachable connections.