Device and method for extracting upper corner gas through underground air jet flow of coal mine

Abstract

The invention relates to the technical field of underground ventilation, in particular to a coal mine underground air jet upper corner gas extraction device which comprises a jet device, the main body of the jet device is in a three-way pipe shape, and the jet device is provided with a first input end, a second input end and a first output end; the first end of the collecting pipe is an air inlet, the air inlet of the collecting pipe is formed in the upper corner area, and the second end of the collecting pipe is connected with the first input end of the jet device; the first end of the extraction pipeline is connected with the first output end of the jet device, and the second end of the extraction pipeline is arranged in an air return roadway area; and the output end of the pressure air output device is connected to the second input end of the jet flow device and used for inputting compressed gas into the inner cavity of the jet flow device, and the device can rapidly extract gas seeping out of the upper corner area underground. Meanwhile, the invention further provides a method for extracting the upper corner gas through the underground coal mine air jet by using the device for extracting the upper corner gas through the underground coal mine air jet.

Description

Technical Field

[0001] The present invention relates to the technical field of underground ventilation, and in particular to a device and method for extracting upper corner gas by air jet in an underground coal mine. Background Art

[0002] The number of high-gas mines and outburst mines in my country is gradually increasing. Gas extraction is of great significance to alleviating coal mine gas accidents. Extracting upper corner gas plays an important role in eliminating gas accumulation and improving mine ventilation. At present, there are many methods and technologies that can be used to extract upper corner gas, including setting up temporary wind barriers in the upper corner, high-position drilling extraction, upper corner buried pipe extraction, gob-side lane exclusion method, wind flow ejector, increasing the air volume of the working face, and return air upper corner airbag filling technology. These methods and technologies have their own advantages and disadvantages, and their scope of application is also different. It is necessary to select the appropriate method according to the specific conditions and actual conditions of the mine. Among them, high-position drilling extraction and upper corner buried pipe extraction are more commonly used methods. High-position drilling extraction is to arrange boreholes at a high position in the goaf, and extract the gas in the goaf through the boreholes and discharge it to the ground or other safe areas, thereby reducing the gas concentration in the upper corner. However, its existing problems cannot be ignored. The effective extraction period of high-position boreholes is short. As the working face advances, the boreholes gradually fall into the caving zone, which will cause cross-wind with the working face and unstable extraction effect. The upper corner buried pipe extraction is to bury pipes at the upper corners, through which the gas in the upper corners is extracted and discharged to the ground or other safe areas, thereby eliminating gas accumulation. The gas pipelines of the upper corner buried pipe extraction are prone to blockage, and untimely extraction and gas accumulation are prone to occur, which may even cause fires, explosions and other accidents. Summary of the invention

[0003] In order to solve the above problems, the present invention provides an air jet device for extracting gas from the upper corners of coal mines. The device is based on fluid mechanics and aerodynamics. It can utilize the air jet principle through Bernoulli's law and the law of conservation of momentum, and utilize a small space and compressed air to mix the upper corner gas with compressed air, thereby accelerating the flow and mixing of the upper corner gas. Through a special air outlet, the gas is ejected into a fixed extraction pipeline in the form of a high-speed jet, thereby achieving the purpose of accelerating the extraction rate of upper corner gas and fundamentally eliminating the gas hazard source, and providing a basis for reducing the gas concentration in the tunnel and ensuring the safety of the underground working environment. The present invention also proposes a method for extracting gas from the upper corners of coal mines by air jet.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] In the first technical solution, an air jet extraction device for upper corner gas in a coal mine comprises:

[0006] A jet device, wherein the main body of the jet device is a three-way tube, and has a first input end, a second input end and a first output end;

[0007] A collecting tube, wherein the first end of the collecting tube is an air inlet, the air inlet of the collecting tube is arranged in the upper corner area, and the second end of the collecting tube is connected to the first input end of the jet device;

[0008] A drainage pipeline, wherein a first end of the drainage pipeline is connected to a first output end of the jet device, and a second end of the drainage pipeline is arranged in a return air lane area;

[0009] A pressure air output device, wherein the output end of the pressure air output device is connected to the second input end of the jet device, and is used for inputting compressed gas into the internal cavity of the jet device.

[0010] In the first technical solution, preferably, the first input end and the first output end are opposite to each other, and the second input end is perpendicular to the conveying direction of the first input end and the first output end, so that the jet device forms a "T"-shaped structure.

[0011] In the first technical solution, preferably, the pipe section of the jet device between the first input end and the first output end is a reduced diameter section.

[0012] In the first technical solution, preferably, the second input end of the jet device is connected to the beginning of the reduced diameter section.

[0013] In the first technical solution, preferably, the first end of the collection tube extends to the middle section of the jet device.

[0014] In the first technical solution, preferably, the second end of the collection tube is a reduced diameter section or a trumpet-shaped structure.

[0015] In the first technical solution, preferably, the pressure air output device is an air compressor.

[0016] In the second technical solution, a method for extracting upper corner gas by air jet in a coal mine is provided, using the device for extracting upper corner gas by air jet in a coal mine as described in the first technical solution, characterized in that the method comprises the following steps:

[0017] On the premise that the device can operate normally, the device is placed at a suitable position in the upper corner area, and the air inlet of the collection pipe is set in the upper corner area; when it is found that the gas concentration in the upper corner is high, the gas monitoring device alarms and it is necessary to extract the local gas, the device is turned on for extraction;

[0018] During the extraction process, the compressed air output device compresses the air. According to Bernoulli's principle, the compressed air enters the jet device to form an annular high-speed flowing gas. Negative pressure is formed in the jet device to suck the gas in the upper corner area into the jet device from the air inlet; the upper corner gas is mixed with the annular high-speed flowing gas after entering the absorption chamber. According to the law of conservation of momentum, the upper corner gas exchanges momentum with the compressed gas and is discharged from the diffuser into the extraction pipeline, and then discharged into the recovery tunnel area;

[0019] When the gas concentration in the upper corner drops below the alarm value, the working face can be mined normally; after the test, the device will be moved as the working face advances to continuously extract the gas from the upper corner to prevent the gas from exceeding the limit in the upper corner during the mining process.

[0020] The beneficial effects of using the present invention are:

[0021] At present, the gas extraction technology for upper corner gas is the high-position drilling of the roof or the buried pipe in the upper corner. The high-position drilling of the roof is costly and time-consuming. The buried pipe process in the upper corner is complicated and takes a long time, which affects the normal recovery speed of the coal mine. In view of this problem, an air jet device for extracting upper corner gas in underground coal mines is designed. The device adopts an air jet device and uses an air compressor to compress air, so that the upper corner gas can be extracted at a higher rate. It is small in size and easy to install and disassemble. The greatly increased extraction rate of upper corner gas in the underground mine fundamentally eliminates the gas hazard source and ensures the safety of the underground working environment. The air jet device for extracting upper corner gas in underground coal mines has the following characteristics:

[0022] The device uses a jet device, which can extract gas at a higher rate. It has no moving parts, generates little heat and no noise. It is used to replace the traditional underground hydraulic vacuum pump, improves the comfort of the working environment of underground workers, and has little pollution to the surrounding environment.

[0023] Compared with traditional underground extraction pumps, this device is smaller in size, easier to install and disassemble, suitable for short-cycle gas extraction, and has a longer service life. Secondly, the design structure of this device greatly improves energy utilization and saves energy. Finally, the air compressor and jet device models can be adjusted according to different underground conditions, suitable for a variety of usage scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the upper corner gas extraction device and method by air jet according to the present invention.

[0025] Reference numerals include:

[0026] 1-upper corner area, 2-air inlet, 3-air compressor, 4-compressed gas, 5-jet device, 6-mixed gas, 7-upper corner gas, 8-diffuser, 9-extraction pipeline, 10-return air tunnel area. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the technical solution more clear, the technical solution is further described in detail below in conjunction with specific implementation methods. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the technical solution.

[0028] In order to solve the problems of easy blockage, untimely extraction and gas accumulation in the existing technology of gas pipelines buried in the upper corner, Figure 1 As shown, this embodiment proposes an air jet extraction upper corner gas device for underground coal mines, including a jet device 5, the main body of the jet device 5 is a three-way tube, which has a first input end, a second input end and a first output end; the first end of the collection pipe is an air inlet 2, the air inlet 2 of the collection pipe is arranged in the upper corner area 1, and the second end of the collection pipe is connected to the first input end of the jet device 5; the first end of the extraction pipeline 9 is connected to the first output end of the jet device 5, and the second end of the extraction pipeline 9 is arranged in the return air tunnel area 10; the output end of the pressure air output device is connected to the second input end of the jet device 5, and is used to input compressed gas 4 into the internal cavity of the jet device 5. In this embodiment, the pressure air output device is an air compressor 3.

[0029] like Figure 1 As shown, in the coal mine underground air jet extraction upper corner gas device in this embodiment, the first input end and the first output end are directly opposite, and the second input end is perpendicular to the conveying direction of the first input end and the first output end, so that the jet device 5 forms a "T"-shaped structure. The pipe section of the jet device 5 between the first input end and the first output end is a reduced diameter section. The second input end of the jet device 5 is connected to the beginning of the reduced diameter section. The first end of the collection pipe extends to the middle section of the jet device 5. The second end of the collection pipe is a reduced diameter section or a trumpet-shaped structure.

[0030] The function of the above structure is to utilize aerodynamic principles, such as the Bernoulli effect and the law of conservation of momentum, to rapidly extract the retained gas in the upper corner area 1. Specifically, the equipment mainly uses an air compressor 3 to compress the air, and the compressed gas 4 enters the jet device 5 through a connecting device to form a high-speed jet flow, and the Bernoulli principle is used to suck the gas from the upper corner area 1 into the jet device 5 from the air inlet 2. After entering the jet device 5, under the action of the compressed gas 4, according to the law of conservation of momentum, the upper corner gas 7 exchanges momentum with the compressed gas 4 in the jet device 5, gradually mixes with the compressed gas 4 to form a mixed gas 6, and is discharged from the diffuser 8 to the extraction pipeline 9, and finally discharged to the return air tunnel area 10.

[0031] This embodiment also proposes a method for extracting upper corner gas by air jet in coal mines, using the above-mentioned upper corner gas extraction device by air jet in coal mines, which is specifically as follows:

[0032] Taking the working face of a mine in production as an example, first, under the premise that the device can operate normally, the device is placed at a suitable position in the upper corner area 1. When it is found that the concentration of gas 7 in the upper corner is high, the gas monitoring device alarms and it is necessary to extract the local gas, so the device is turned on for extraction.

[0033] The air compressor 3 compresses the air. According to Bernoulli's principle, the compressed air enters the jet device 5 to form an annular high-speed flowing gas. Negative pressure is formed in the jet device 5 to suck the gas in the upper corner area 1 into the jet device 5 from the air inlet 2. The upper corner gas 7 is mixed with the annular high-speed flowing gas after entering the absorption chamber. According to the law of conservation of momentum, the upper corner gas 7 exchanges momentum with the compressed gas 4 and is discharged from the diffuser 8 to the extraction pipeline 9, and then discharged into the recovery tunnel area.

[0034] When the concentration of upper corner gas 7 drops below the alarm value, the working face can be mined normally. After the test, the device is moved along with the advancement of the working face to continuously extract the upper corner gas 7 to prevent the upper corner gas 7 from exceeding the limit during the mining process.

[0035] Combined with the above-mentioned device and method, in general, the technical solution assembles the air compressor 3, the jet device 5, and the diffuser 8 in a suitable area of ​​the upper corner of the well, and connects the diffuser 8 to the extraction pipeline 9. Start the air compressor 3, the device starts to run, and the upper corner gas 7 is extracted.

[0036] The device uses air jets, and the air compressor 3 presses the compressed gas 4 into the jet device 5. The high-speed rotation of the compressed gas 4 forms a negative pressure in the space of the jet device 5, and the upper corner gas 7 is extracted from the upper corner, mixed with the compressed gas 4 in the space, and discharged from the diffuser 8. The extraction rate of the upper corner gas 7 is faster than that of ordinary negative pressure extraction, and is more convenient and economical than methods such as high-position hole drilling and upper corner pipe burying.

[0037] The present invention utilizes the air jet method to reduce the extraction time of the upper corner gas 7 and the cost of drilling and pipe laying, effectively solves the problem of upper corner gas 7 exceeding the limit, accelerates the extraction rate of upper corner gas 7, and ensures the underground working environment.

[0038] At present, the extraction of upper corner gas 7 adopts the roof high-position drilling gas extraction technology or upper corner buried pipe. The cost of drilling high-position holes in the roof is high and it takes a long time. The upper corner buried pipe process is complicated and takes a long time, which affects the normal recovery rate of the coal mine. In view of this problem, an air jet extraction upper corner gas device is designed for underground coal mines. The device adopts an air jet device 5 and uses an air compressor 3 to compress the air so that the upper corner gas 7 can be extracted at a higher rate. It is small in size and easy to install and disassemble. The greatly increased extraction rate of the upper corner gas 7 underground fundamentally eliminates the gas hazard source and ensures the safety of the underground working environment. The underground coal mine air jet extraction upper corner gas device has the following characteristics:

[0039] The device adopts a jet device 5, which can extract gas at a higher rate. It has no moving parts, generates little heat and no noise, and is used to replace the traditional underground hydraulic vacuum pump, thereby improving the comfort of the working environment of underground workers and causing little pollution to the surrounding environment.

[0040] Compared with the traditional underground extraction pump, the device is smaller in size, easy to install and disassemble, suitable for short-cycle gas extraction, and has a long service life. Secondly, the design structure of the device greatly improves the energy utilization rate and saves energy. Finally, the models of the air compressor 3 and the jet device 5 can be adjusted according to different underground conditions, which is suitable for a variety of usage scenarios.

[0041] It should be noted that, in the description of the present invention, unless otherwise specified, the meaning of "multiple" is two or more; the orientation or position relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. At the same time, in the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0042] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, many changes can be made in the specific implementation methods and application scopes based on the ideas of the present technical content. As long as these changes do not deviate from the concept of the present invention, they all fall within the scope of protection of this patent.

Claims

1. An air jet extraction device for upper corner gas in underground coal mines, characterized in that: include A jet device, wherein the main body of the jet device is a three-way tube, and has a first input end, a second input end and a first output end; A collecting tube, wherein the first end of the collecting tube is an air inlet, the air inlet of the collecting tube is arranged in the upper corner area, and the second end of the collecting tube is connected to the first input end of the jet device; A drainage pipeline, wherein a first end of the drainage pipeline is connected to a first output end of the jet device, and a second end of the drainage pipeline is arranged in a return air lane area; A pressure air output device, wherein the output end of the pressure air output device is connected to the second input end of the jet device, and is used for inputting compressed gas into the internal cavity of the jet device.

2. The device for extracting upper corner gas from air jet in underground coal mines according to claim 1, characterized in that: The first input end and the first output end are directly opposite to each other, and the second input end is perpendicular to the conveying direction of the first input end and the first output end, so that the jet device forms a "T"-shaped structure.

3. The device for extracting upper corner gas from air jet in underground coal mines according to claim 2, characterized in that: The pipe section between the first input end and the first output end of the jet device is a reduced diameter section.

4. The device for extracting upper corner gas from air jet in underground coal mines according to claim 3 is characterized in that: The second input end of the jet device is connected to the beginning of the reduced diameter section.

5. The device for extracting upper corner gas from air jet in underground coal mines according to claim 3 is characterized in that: The first end of the collection tube extends to the middle section of the jet device.

6. The device for extracting upper corner gas from air jet in underground coal mines according to claim 5, characterized in that: The second end of the collection tube is a reduced diameter section or a trumpet-shaped structure.

7. The device for extracting upper corner gas from air jet in underground coal mines according to claim 1, characterized in that: The pressure air output device is an air compressor.

8. A method for extracting upper corner gas by air jet in a coal mine, using the device for extracting upper corner gas by air jet in a coal mine as claimed in any one of claims 1 to 7, characterized in that: The method comprises the following steps: On the premise that the device can operate normally, the device is placed at a suitable position in the upper corner area, and the air inlet of the collection pipe is set in the upper corner area; when it is found that the gas concentration in the upper corner is high, the gas monitoring device alarms and it is necessary to extract the local gas, the device is turned on for extraction; During the extraction process, the compressed air output device compresses the air. According to Bernoulli's principle, the compressed air enters the jet device to form an annular high-speed flowing gas. Negative pressure is formed in the jet device to suck the gas in the upper corner area into the jet device from the air inlet; the upper corner gas is mixed with the annular high-speed flowing gas after entering the absorption chamber. According to the law of conservation of momentum, the upper corner gas exchanges momentum with the compressed gas and is discharged from the diffuser into the extraction pipeline, and then discharged into the recovery tunnel area; When the gas concentration in the upper corner drops below the alarm value, the working face can be mined normally; after the test, the device will be moved as the working face advances to continuously extract the gas from the upper corner to prevent the gas from exceeding the limit in the upper corner during the mining process.

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