Device for testing firmness coefficient of frozen coal sample containing gas
By designing an automated frozen coal sample testing device, the problem of testing the solidity coefficient of coal sample in low temperature environments in the prior art is solved, and the rigidity coefficient of coal sample is accurately measured in the frozen state is achieved, which simplifies the operating process and improves the testing accuracy.
Patent Information
- Application Number
- CN202422126025.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-30
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-08-30
AI Technical Summary
The existing coal sample robustness coefficient test device cannot be tested in low temperature environments. The frozen coal sample is easy to melt, manual operation is cumbersome and the test error is large, so it cannot truly reflect the strength of the gas-containing coal body.
A test device including a freezer cabinet, a support table, a support column, a cylindrical cylinder, an electromagnet and a drop hammer was designed. The drop hammer hits the frozen coal sample many times, and screens and collects it in the freezer cabinet to ensure the stability of the test.
It realizes automatic testing of the solidity coefficient of frozen coal samples in low temperature environments, reduces errors, ensures the accuracy and stability of the test results, and can truly reflect the impact of different low temperature environments on the solidity of coal samples.
Smart Images
Figure CN223078088U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of coal mine safety, in particular to a device for testing the solidity coefficient of frozen coal samples containing gas. Background Technique
[0002] Coal and gas outburst seriously affects the safety production of coal mines. In particular, the prevention and control of gas outburst during cross-cut uncovering of coal seams and in geological structure zones have become difficult problems that China urgently needs to overcome. The existing measures for preventing and controlling coal and gas outburst pay more attention to reducing the energy storage of coal seams and do not attach enough importance to improving the strength of coal bodies. Gas pressure and coal body strength are two key factors affecting coal and gas outburst. On the one hand, cryogenic freezing can inhibit gas desorption - reduce gas pressure, and on the other hand, it can improve the strength of coal bodies. Inspired by this, a new idea of freezing for outburst prevention has emerged: while implementing gas drainage measures according to regulations, artificial freezing is carried out on local areas such as cross-cut uncovering of coal seams or geological structure zones to quickly reduce the energy storage of coal seams and improve the strength of coal bodies, and effectively eliminate the gas outburst risk at cross-cut uncovering locations and in geological structure zones. The solidity coefficient of coal can characterize the strength characteristics of coal bodies, reflect the damage effect of coal bodies against in-situ stress and gas pressure, and the resistance to the initiation of coal and gas outburst.
[0003] Whether the measures of coal seam water injection plus artificial freezing can improve the strength of coal bodies or how much the strength of coal bodies has increased need to be proved through experiments. This involves a device for testing the solidity coefficient of frozen coal samples containing gas, which can test the solidity coefficient of coal samples under different low-temperature environments to explore the influence of low-temperature environments on the solidity coefficient of coal samples, and lay a theoretical foundation for mastering the freezing response characteristics of coal samples containing gas and the freezing outburst prevention mechanism.
[0004] However, the existing devices for testing the solidity coefficient of coal samples can only test the collected coal samples at room temperature. In terms of current instruments and equipment, it is difficult to test the solidity coefficient of frozen coal samples. The existing devices mainly have the following deficiencies:
[0005] 1. The frozen coal samples may melt after being taken out;
[0006] 2. Even if the frozen coal samples are taken out, the coal samples may melt when the drop hammer breaks the coal samples;
[0007] 3. The coal contains moisture, and the coal powder is extremely easy to become mud and cannot be screened;
[0008] 4. Manually operating the drop hammer is cumbersome, time-consuming and laborious, and the test error is relatively large;
[0009] 5. Most of the existing experiments test the solidity coefficient of coal samples when the coal body is exposed to the air, and cannot truly reflect the strength of coal bodies containing gas. Summary of the Invention
[0010] The purpose of the present utility model is to solve the deficiencies existing in the prior art and provide a device for testing the solidity coefficient of frozen gas-containing coal samples.
[0011] To achieve the above object, the present utility model is implemented according to the following technical solution:
[0012] A device for testing the solidity coefficient of frozen gas-containing coal samples, including a freezing cabinet body. A transparent cabinet door is provided on the front end face of the freezing cabinet body. A support table is fixed at the bottom inside the freezing cabinet body. A support column for supporting the frozen coal sample is fixed on the upper end face of the support table. A cylindrical barrel concentric with the support column is provided directly above the support column. The outer diameter of the cylindrical barrel is smaller than the diameter of the support column. An O-ring seal is provided at the bottom of the cylindrical barrel. The cylindrical barrel is connected to a first driving mechanism for driving the cylindrical barrel to move up and down in the vertical direction. The top end of the cylindrical barrel is detachably connected to a sealing cover body. A through hole is provided in the center of the sealing cover body. An electromagnet concentric with the cylindrical barrel is provided through the through hole. An O-ring seal is provided in the through hole. The electromagnet is connected to a second driving mechanism for driving the electromagnet to move up and down in the vertical direction. A drop hammer that can fall into the cylindrical barrel is electromagnetically connected to the lower end of the electromagnet. A pushing mechanism for pushing down the broken frozen coal sample is provided on one side of the upper end face of the support column. A concave sieve is provided inside the freezing cabinet body below the cylindrical barrel. The lower end of the concave sieve is fixedly connected to a funnel. The top end of the support column penetrates through the funnel and the top end of the concave sieve. A vibrator connected to the bottom of the funnel is fixed on the support table. The bottom of the funnel is detachably connected to a measuring cylinder. The measuring cylinder is located on one side of the support table. A trachea is connected to the top end of the sealing cover body. The trachea extends outside the freezing cabinet body and is connected to a high-pressure methane gas cylinder. A manual valve and a booster pump are successively provided at the output end of the high-pressure methane gas cylinder. A pressure gauge is provided on the other side of the top end of the sealing cover body.
[0013] Further, the first driving mechanism includes a fixed barrel fixed outside the cylindrical barrel. Connecting rods are connected to both side walls of the fixed barrel. First sliders are provided at the ends of the connecting rods. The first sliders are slidably assembled in longitudinal chutes provided on the inner walls of both sides of the freezing cabinet body. A first servo motor is fixed at the top of the freezing cabinet body. The output shaft end of the first servo motor extends into the freezing cabinet body and axially fixes a first lead screw. The lower part of the first lead screw is threadedly connected to a first threaded hole provided on one of the connecting rods.
[0014] Further, the second driving mechanism includes a cross bar. The top end of the electromagnet is fixed on the cross bar. Second sliders slidably engaged with the chutes are provided at both ends of the cross bar. A second servo motor is fixed at the top of the freezing cabinet body. The output shaft end of the second servo motor extends into the freezing cabinet body and axially fixes a second lead screw. The lower part of the second lead screw is threadedly connected to a second threaded hole provided on one of the cross bars. The top end of the first lead screw penetrates through a through hole provided on the cross bar.
[0015] Further, the pushing mechanism includes an electric push rod and a push plate. The electric push rod is fixed on a support frame arranged outside the freezer cabinet. The rod end of the electric push rod penetrates through the side wall of the freezer cabinet body and extends into the freezer cabinet body, and is fixedly connected to the rear end face of the push plate. The lower end face of the push plate is in contact with the upper end face of the support column.
[0016] Further, the bottom of the funnel is provided with internal threads, and the top of the graduated cylinder is provided with external threads. The top of the graduated cylinder is assembled to the bottom of the funnel through the threads.
[0017] Further, when the first slider slides to the bottom of the longitudinal chute, the bottom of the cylindrical barrel is completely attached to the upper end face of the support column.
[0018] Compared with the prior art, the utility model can electrically control the drop hammer to impact the frozen coal sample multiple times as needed. After multiple impacts, the broken coal samples can be centrally collected. Finally, after being screened by the concave sieve mesh, they are collected by the funnel and enter the graduated cylinder; the whole process is carried out inside the freezer cabinet, ensuring the test stability of the frozen coal sample; at the same time, the utility model can test the firmness coefficient of the gas-containing coal sample under different low-temperature environments to analyze the influence of the low-temperature environment on the firmness coefficient of the coal sample, laying a theoretical foundation for mastering the freezing response characteristics and freezing outburst prevention mechanism of the gas-containing coal. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a schematic structural diagram of the utility model.
[0020] Figure 2 is a diagram of the use state of the utility model.
[0021] Figure 3 is an installation schematic diagram of the vibrator.
[0022] Figure 4 is an installation schematic diagram of the vibrator
[0023] Figure 5 is Figure 1 an enlarged view of part A of DETAILED DESCRIPTION OF THE EMBODIMENTS
[0024] In order to make the purpose, technical solutions and advantages of the utility model clearer, the following further describes the utility model in detail with reference to the drawings and embodiments. The specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model.
[0025] As Figures 1 to 5As shown, this embodiment exemplarily shows a device for testing the solidity coefficient of frozen gas-containing coal samples, including a freezing cabinet body 1. The refrigeration mechanism 101 of the freezing cabinet body 1 is arranged outside one side of the bottom of the freezing cabinet body 1. It should be noted that the freezing cabinet body 1 and the refrigeration mechanism 101 can be directly purchased on the market, as long as a certain constant low temperature between 0°C and -40°C can be maintained inside the freezing cabinet body 1; a transparent cabinet door (not shown in the figure) is provided on the front end face of the freezing cabinet body 1. A support platform 2 is fixed at the inner bottom of the freezing cabinet body 1. A support column 3 for supporting the frozen coal sample is fixed on the upper end face of the support platform 2. A cylindrical barrel 4 concentric with the support column 3 is provided directly above the support column 3. The outer diameter of the cylindrical barrel 4 is smaller than the diameter of the support column 3. An O-ring seal is provided at the bottom of the cylindrical barrel 4 to ensure the sealing performance when the bottom of the cylindrical barrel 4 contacts the support column 3. The cylindrical barrel 4 is connected to a first driving mechanism for driving the cylindrical barrel 4 to move up and down in the vertical direction; the top end of the cylindrical barrel 4 is connected with a sealing cover body 24 by threads. A through hole is provided in the center of the sealing cover body 24. An electromagnet 14 concentric with the cylindrical barrel 4 passes through the through hole. An O-ring seal is provided in the through hole to achieve dynamic sealing when the electromagnet 14 slides in the through hole. The electromagnet 14 in this embodiment can be directly purchased on the market. The top end of the electromagnet 14 is connected with a wire connected to the coil on the iron core of the electromagnet. The wire extends outside the freezing cabinet body 1 and then is connected to a power source; the electromagnet 14 is connected to a second driving mechanism for driving the electromagnet 14 to move up and down in the vertical direction; a drop hammer 13 that can fall into the cylindrical barrel 4 is electromagnetically connected to the lower end of the electromagnet 14. In this embodiment, the weight of the drop hammer 13 is 2.4 kg; a pushing mechanism for pushing the broken frozen coal sample is provided on one side of the upper end face of the support column 3. A concave sieve 20 is provided in the freezing cabinet body 1 below the cylindrical barrel 4. The aperture of the sieve holes of the concave sieve 20 is 0.5 mm. A funnel 21 is fixedly connected to the lower end of the concave sieve 20. The top end of the support column 3 passes through the funnel 21 and the top end of the concave sieve 20. An exciter 23 connected to the bottom of the funnel 21 is fixed on the support platform 2; an internal thread is provided at the bottom of the funnel 21, and an external thread is provided at the top end of the measuring cylinder 22. The top end of the measuring cylinder 22 is assembled to the bottom of the funnel 21 by threads. The measuring cylinder 22 is located on one side of the support platform 2; a trachea 25 is connected to the top end of the sealing cover body. The trachea extends outside the freezing cabinet body and is connected to a high-pressure methane gas cylinder (not shown in the figure). A manual valve and a booster pump (not shown in the figure) are successively provided at the output end of the high-pressure methane gas cylinder; a pressure gauge 26 is provided on the other side of the top end of the sealing cover body.
[0026] Specifically, the first driving mechanism includes a fixed cylinder 5 fixed outside the cylindrical cylinder body 4. Connecting rods 6 are connected to both side walls of the fixed cylinder 5. The ends of the connecting rods 6 are provided with first sliders 9, and the first sliders 9 are slidably assembled in the longitudinal chutes 102 opened on both inner walls of the freezer cabinet 1. A first servo motor 8 is fixed on the top of the freezer cabinet 1. The end of the output shaft of the first servo motor 8 extends into the freezer cabinet 1 and is axially fixed with a first lead screw 7. The lower part of the first lead screw 7 is threadedly connected to a first threaded hole opened on one of the connecting rods 6.
[0027] As Figures 1 to 5 shown, in this embodiment, in order to facilitate lifting the drop hammer 13 and enabling the drop hammer 13 to freely fall at a certain height, the second driving mechanism includes a cross bar 15. The top of the electromagnet 14 is fixed on the cross bar 15. Second sliders 18 slidably engaged with the chutes 102 are provided at both ends of the cross bar 15. A second servo motor 17 is fixed on the top of the freezer cabinet 1. The end of the output shaft of the second servo motor 17 extends into the freezer cabinet 1 and is axially fixed with a second lead screw 16. The lower part of the second lead screw 16 is threadedly connected to a second threaded hole opened on one of the cross bars 15. The top of the first lead screw 7 penetrates through a through hole 19 opened on the cross bar 15.
[0028] As Figure 1 shown, in this embodiment, in order to quickly push the crushed frozen coal sample off the top of the support column 3, the pushing mechanism includes an electric push rod 11 and a push plate 10. The electric push rod 11 is fixed on a support frame 12 arranged outside the freezer cabinet 1. The end of the push rod of the electric push rod 11 penetrates through the side wall of the freezer cabinet 1 and extends into the freezer cabinet 1 and is fixedly connected to the rear end face of the push plate 10. The lower end face of the push plate 10 is in contact with the upper end face of the support column 3.
[0029] During actual use, in order to simplify control, when the first slider 9 slides to the bottom of the longitudinal chute 102, the bottom of the cylindrical cylinder body 4 is completely attached to the upper end face of the support column 3.
[0030] Referring to Figure 1 、 Figure 2, when it is necessary to test the solidity coefficient of the frozen coal sample, the temperature inside the freezing cabinet 1 is adjusted by the refrigeration mechanism 101 to, for example, -20°C. The ejector rod of the electric push rod 11 is controlled to retract, driving the push plate 10 to move to the left end of the support column 3. The cylindrical barrel 4 is driven by the first servo motor 8 to move downward until the bottom of the cylindrical barrel 4 is completely attached to the upper end surface of the support column 3. The sealing cover 24 is opened, and the frozen coal sample is placed into the cylindrical barrel 4. The electromagnet 14 is driven by the second servo motor 17 to move upward above the cylindrical barrel 4. The output end of the high-pressure methane gas cylinder is successively provided with a manual valve and a booster pump. Methane gas is injected into the sealed cylindrical barrel 4 through the air pipe 25. When the pressure inside the cylindrical barrel 4 is observed by the pressure gauge 26 on one side of the plunger to reach a certain pressure (generally 0.74 Mpa), the manual valve and the booster pump are closed; then the electromagnet 14 is not powered off, so that the drop hammer 13 is lifted above the cylindrical barrel 4, and the lower end surface of the drop hammer 13 is 600 mm away from the top of the support column 3. The transparent cabinet door is opened, and each time 50 g of frozen coal sample with a particle size of 1 - 3 mm is added to the cylindrical barrel 4. The transparent cabinet door is closed, and then the electromagnet 14 is powered off to make the drop hammer fall freely and impact the frozen coal sample. Each frozen coal sample is impacted 5 times by the drop hammer; after the impact, the cylindrical barrel 4 is driven by the first servo motor 8 to move upward until the bottom of the cylindrical barrel 4 is above the push plate 10. Then, the ejector rod of the electric push rod 11 is reciprocated to drive the push plate 10 to push the crushed frozen coal sample at the top of the support column 3 onto the concave sieve 20; after all five frozen coal samples are crushed, the vibrator 23 is started, and the frozen coal sample with a particle size less than 0.5 mm is screened out through the concave sieve 20 and collected by a graduated cylinder with a diameter of 23 mm. The height h of the powder in the graduated cylinder is measured and recorded. Finally, the solidity coefficient f value of the frozen coal sample is calculated according to the formula for testing the solidity coefficient of the coal sample by the conventional drop hammer method in the art; after the test, the concave sieve and the graduated cylinder are cleaned after opening the transparent cabinet door to facilitate subsequent tests; the temperature inside the freezing cabinet 1 is adjusted by the refrigeration mechanism 101 to test the solidity coefficient of the gas-containing coal sample under different low-temperature environments.
[0031] The technical solution of the present invention is not limited to the limitations of the above specific embodiments. Any technical deformation made according to the technical solution of the present invention falls within the protection scope of the present invention.
Claims
1. A device for testing the solidity coefficient of frozen coal samples containing gas, comprising a freezing cabinet body, characterized in that: A transparent cabinet door is provided on the front end face of the freezer cabinet body. A support platform is fixed at the bottom inside the freezer cabinet body. A support column for supporting the frozen coal sample is fixed on the upper end face of the support platform. A cylindrical barrel concentric with the support column is provided directly above the support column. The outer diameter of the cylindrical barrel is smaller than the diameter of the support column. An O-ring seal is provided at the bottom of the cylindrical barrel. The cylindrical barrel is connected to a first driving mechanism for driving the cylindrical barrel to move up and down in the vertical direction. A sealing cover body is detachably connected to the top end of the cylindrical barrel. A through hole is provided in the center of the sealing cover body. An electromagnet concentric with the cylindrical barrel is provided through the through hole. An O-ring seal is provided in the through hole. The electromagnet is connected to a second driving mechanism for driving the electromagnet to move up and down in the vertical direction. A drop hammer that can fall into the cylindrical barrel is electromagnetically connected to the lower end of the electromagnet. A pushing mechanism for pushing the broken frozen coal sample is provided on one side of the upper end face of the support column. A concave sieve is provided inside the freezer cabinet body below the cylindrical barrel. The lower end of the concave sieve is fixedly connected to a funnel. The top end of the support column penetrates through the funnel and the top end of the concave sieve. A vibrator connected to the bottom of the funnel is fixed on the support platform. A measuring cylinder is detachably connected to the bottom of the funnel. The measuring cylinder is located on one side of the support platform. A trachea is connected to the top end of the sealing cover body. The trachea extends outside the freezer cabinet body and is connected to a high-pressure methane gas cylinder. A manual valve and a booster pump are sequentially provided at the output end of the high-pressure methane gas cylinder. A pressure gauge is provided on the other side of the top end of the sealing cover body.
2. The device for testing the solidity coefficient of frozen gas-containing coal samples according to claim 1, wherein: The first driving mechanism includes a fixed cylinder fixed outside the cylindrical barrel. Connecting rods are connected to the two side walls of the fixed cylinder. First sliders are provided at the ends of the connecting rods. The first sliders are slidably assembled in longitudinal chutes provided on the inner walls of the two sides of the freezer cabinet body. A first servo motor is fixed at the top of the freezer cabinet body. The output shaft end of the first servo motor extends into the freezer cabinet body and a first lead screw is axially fixed. The lower part of the first lead screw is threadedly connected to a first threaded hole provided on the connecting rod on one side.
3. The device for testing the solidity coefficient of frozen gas-containing coal samples according to claim 2, characterized in that: The second driving mechanism includes a cross bar. The top end of the electromagnet is fixed on the cross bar. Second sliders that are slidably matched with the chutes are provided at both ends of the cross bar. A second servo motor is fixed at the top of the freezer cabinet body. The output shaft end of the second servo motor extends into the freezer cabinet body and a second lead screw is axially fixed. The lower part of the second lead screw is threadedly connected to a second threaded hole provided on the cross bar on one side. The top end of the first lead screw penetrates through a through hole provided on the cross bar.
4. The device for testing the firmness coefficient of a frozen gas-containing coal sample according to claim 1, wherein: The pushing mechanism includes an electric push rod and a push plate. The electric push rod is fixed on a support frame provided outside the freezer cabinet body. The push rod end of the electric push rod penetrates through the side wall of the freezer cabinet body and extends into the freezer cabinet body and is fixedly connected to the rear end face of the push plate. The lower end face of the push plate is in contact with the upper end face of the support column.
5. The device for testing the solidity coefficient of frozen gas-containing coal samples according to claim 1, characterized in that: Internal threads are provided at the bottom of the funnel. External threads are provided at the top end of the measuring cylinder. The top end of the measuring cylinder is threadedly assembled at the bottom of the funnel.
6. The device for testing the solidity coefficient of frozen gas-containing coal samples according to claim 2, characterized in that: When the first slider slides to the bottom of the longitudinal chute, the bottom of the cylindrical barrel is completely attached to the upper end face of the support column.