Reaction device for treating low-concentration methane in coal mine exhaust air

Abstract

The utility model discloses a reaction device for treating low-concentration methane in coal mine exhaust air, which comprises a reactor, the upper part of the reactor is communicated with a separation device, the gas end of the separation device is communicated with a flue gas connecting passage, an afterburning device is arranged on the flue gas connecting passage, and the flue gas connecting passage is communicated with a hot side passage of a gas-gas heat exchanger; a cold side passage of the gas-gas heat exchanger is communicated with a hot air passage; and the hot air passage is communicated with the lower part of the reactor. The device has the beneficial effects that an arrangement scheme of a reaction device for treating high-flow and low-concentration methane in coal mine exhaust air is provided, the shortage of related equipment described in the background technology is solved, and the problem of greenhouse effect caused by emission of low-concentration methane in coal mine exhaust air is obviously reduced.

Description

Technical Field

[0001] This application belongs to the technical field of methane emission reduction, and particularly relates to a reaction device for treating low-concentration methane in coal mine ventilation air, which can more effectively treat large-flow and low-concentration methane. Background Art

[0002] Methane is the second largest greenhouse gas globally. The methane concentration in coal mine ventilation gas is low, and it is difficult to utilize, so it has long been discharged into the atmosphere. According to statistics from relevant departments, the amount of methane discharged into the atmosphere in the form of coal mine ventilation gas in China every year is equivalent to the annual gas transmission volume of the West-East Gas Pipeline Project, and the resulting warming gas effect is about 200 million tons of carbon dioxide equivalent.

[0003] Existing technologies for treating low-concentration methane mainly include feeding it into a coal-fired boiler for combustion assistance, regenerative combustion, regenerative catalytic oxidation, etc., but all of them have problems in being difficult to apply at low cost and on a large scale. There is no mature technology and reliable equipment for treating large-flow and low-concentration methane.

[0004] As the issue of global warming has attracted increasing attention from the international community, how to efficiently and low-cost dispose of these large-flow and low-concentration methane gases has become a difficult problem to tackle worldwide. Utility Model Content

[0005] The purpose of this application is to provide a reaction device for treating low-concentration methane in coal mine ventilation air, aiming at effectively treating large-flow and low-concentration methane in coal mine ventilation air, greatly reducing the methane concentration in coal mine ventilation air, with the methane concentration decreasing by more than 90% after the reaction, thereby reducing the greenhouse effect.

[0006] The purpose of this application is achieved through the following technical solutions:

[0007] A reaction device for treating low-concentration methane in coal mine ventilation air includes a reactor. The upper part of the reactor is connected to a separation device. The gas end of the separation device is connected to a flue gas connection passage. A supplementary combustion device is provided on the flue gas connection passage. The flue gas connection passage is connected to the hot side passage of a gas-gas heat exchanger. The cold side passage of the gas-gas heat exchanger is connected to a hot air passage. The hot air passage is connected to the lower part of the reactor.

[0008] Further, the material end of the separation device is connected to a recovery device, and the recovery device is connected to the lower part of the reactor.

[0009] Further, a feeding device is provided at the lower part of the reactor, and an ignition device and a slag discharge device are provided at the bottom of the reactor. The ignition device is located at the outlet of the hot air passage.

[0010] Further, the interior of the reactor has a structure without equipment layout and / or a structure without heating surface layout.

[0011] Further, the reactor is a reaction channel with a reaction time of at least 2 seconds.

[0012] Further, the range of the particle size a of the material in the reactor is 100 μm ≤ a ≤ 800 μm, the range of the flue gas velocity b in the reactor is 4 m / s ≤ b ≤ 6 m / s, and the range of the reactor height c is c > 2b.

[0013] Further, the range of the inner diameter d of the separation device is 1 m ≤ d ≤ 10 m, the range of the net clearance height e at the inlet of the separation device is 0.8d ≤ e ≤ 1.3d, the minimum value f of the net clearance width at the inlet of the separation device is 0.2d ≤ f ≤ 0.4d, and the range of the angle g of the lower conical section of the separation device is 70° ≤ g ≤ 80°.

[0014] Further, the range of the height i at which the recovery device is connected to the furnace is 0.5 m ≤ i ≤ 3.5 m.

[0015] Further, the type of the gas-gas heat exchanger is a tubular gas-gas heat exchanger or a rotary gas-gas heat exchanger; when the tubular gas-gas heat exchanger is selected for the gas-gas heat exchanger, the heat exchanger tubes use spiral groove tubes, and the range of the inner diameter j of the heat exchanger tubes is 30 mm ≤ j ≤ 60 mm.

[0016] Further, the range of the feeding height h of the feeding device is 0.5 m ≤ h ≤ 3 m.

[0017] The beneficial effects of this application: A layout scheme of a reaction device for treating large-flow and low-concentration methane in coal mine exhaust air is given, solving the shortage of related equipment described in the background technology, and significantly reducing the greenhouse effect problem caused by low-concentration methane emissions in coal mine exhaust air.

[0018] The main solution of the foregoing application and its various further selection solutions can be freely combined to form multiple solutions, all of which are solutions that can be adopted and claimed in this application; and in this application, (each non-conflicting selection) can be freely combined between selections and with other selections. Those skilled in the art can understand that there are various combinations according to the prior art and common general knowledge after understanding this solution, all of which are the technical solutions to be protected in this application, and will not be enumerated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural diagram of this application.

[0020] Figure 2 is a top view of the structures of the reactor and the separation device of this application.

[0021] In the figure: 1 - reactor, 2 - separation device, 3 - recovery device, 4 - gas-gas heat exchanger, 5 - flue gas connection path, 6 - afterburning device, 7 - hot air path, 8 - ignition device, 9 - slag discharge device, 10 - feeding device. Detailed implementation manners

[0022] The present application will be further described below in conjunction with specific embodiments and the accompanying drawings.

[0023] Referring to Figure 1 and Figure 2 As shown, a reaction device for treating low-concentration methane in coal mine exhaust air includes a reactor 1, a separation device 2, a recovery device 3, a gas-gas heat exchanger 4, a flue gas connection path 5, an afterburning device 6, a hot air path 7, an ignition device 8, a slag discharge device 9, and a feeding device 10.

[0024] The reactor 1 is a separate container, and the interior of the reactor 1 has a structure without equipment layout and / or a structure without heating surface layout. The upper part of the reactor 1 is communicated with the separation device 2, and the lower part of the reactor 1 is communicated with the recovery device 3. The separation device 2 separates the reacted gas and materials, and the material end of the separation device 2 is communicated with the recovery device 3 for recycling the separated materials back into the reactor 1 for reuse.

[0025] The gas end of the separation device 2 is communicated with the flue gas connection path 5, and the flue gas connection path 5 is communicated with the hot side path of the gas-gas heat exchanger 4 to introduce the separated flue gas into the gas-gas heat exchanger 4 for heat recovery. The gas separated by the separation device enters the gas-gas heat exchanger through the flue gas connection path. In the gas-gas heat exchanger, the high-temperature flue gas exchanges heat with the air containing low-concentration methane directly extracted from the coal mine to heat the air temperature to 400 - 600 °C.

[0026] The afterburning device 6 is provided on the flue gas connection path 5. When the methane concentration in the air is too low, the flue gas is heated by afterburning to increase the hot air temperature after the gas-gas heat exchanger, so as to maintain the reaction temperature in the reactor. Arranging the afterburning device here is beneficial to monitoring the reduction of methane concentration, can also better control the reaction temperature in the reactor, and does not affect the temperature distribution in the reactor.

[0027] The cold side path of the gas-gas heat exchanger 4 is communicated with the hot air path 7, and the hot air path 7 is communicated with the lower part of the reactor 1. The air containing low-concentration methane directly extracted from the coal mine absorbs the heat of the flue gas to achieve temperature rise, and then the air heated by the gas-gas heat exchanger enters the reactor through the bottom of the reactor for catalytic oxidation to achieve the treatment of methane, and the flue gas cooled by the gas-gas heat exchanger is discharged from the tail.

[0028] The lower part of the reactor 1 is provided with a feeding device 10, and the bottom of the reactor 1 is provided with an ignition device 8 and a slag discharging device 9. The ignition device 8 is located at the outlet of the hot air passage 7. The material is fed into the reactor through the feeding device and discharged from the reactor through the slag discharging device.

[0029] The methane concentration in the flue gas in the area before the afterburning device in the flue gas connection passage is reduced by more than 90% compared with the methane concentration in the air just fed into the reactor, greatly reducing the greenhouse effect caused by methane emissions.

[0030] The design of the reactor needs to consider the methane reaction time in the reactor. The reactor 1 is a reaction channel with a reaction time of at least 2 seconds. The range of the particle size a of the material in the reactor 1 is 100μm ≤ a ≤ 800μm, the range of the flue gas velocity b in the reactor 1 is 4m / s ≤ b ≤ 6m / s, and the range of the height c of the reactor 1 is c > 2b.

[0031] The separation device 2 uses a cyclone separator. The range of the inner diameter d of the separation device 2 is 1m ≤ d ≤ 10m, the range of the net clearance height e at the inlet of the separation device 2 is 0.8d ≤ e ≤ 1.3d, the minimum value f of the net clearance width at the inlet of the separation device 2 is 0.2d ≤ f ≤ 0.4d, and the range of the angle g of the lower conical section of the separation device is 70° ≤ g ≤ 80°.

[0032] The range of the height i at which the recovery device 3 is connected to the furnace is 0.5m ≤ i ≤ 3.5m.

[0033] The type of the gas-gas heat exchanger 4 is a tubular gas-gas heat exchanger or a rotary gas-gas heat exchanger. When the gas-gas heat exchanger 4 is selected as a tubular gas-gas heat exchanger, the heat exchanger tubes use spiral groove tubes, and the range of the inner diameter j of the heat exchanger tubes is 30mm ≤ j ≤ 60mm.

[0034] The range of the feeding height h of the feeding device 10 is 0.5m ≤ h ≤ 3m.

[0035] Example

[0036] Reference Figure 1 And Figure 2 As shown, a reaction device for treating low-concentration methane in coal mine exhaust air includes a reactor 1, a separation device 2, a recovery device 3, a gas-gas heat exchanger 4, a flue gas connection passage 5, an afterburning device 6, a hot air passage 7, an ignition device 8, a slag discharging device 9, and a feeding device 10.

[0037] The treatment flow rate is 10,000 Nm 3 / h, the exhaust air of a coal mine with a methane volume content of 0.2%. Reactor 1 is a single container. The flue gas velocity b is selected as 5 m / s. The height c of Reactor 1 is 15 m. The upper part is connected to the separation device 2. The inner diameter d of the separation device 2 is 1 m. The angle g of the lower cone section of the separation device 2 is 75°. A feeding device 10 is arranged at the lower part of Reactor 1. The feeding height h of the feeding device 10 is 1.8 m. The lower part is connected to the recovery device 3. The height i at which the recovery device is connected to the furnace is 1.8 m. A slag discharging device 9 and an ignition device 8 are arranged at the bottom. The flue gas generated by Reactor 1 enters the gas-gas heat exchanger 4 after passing through the separation device 2 and then entering the flue gas connection path 5. Since the methane concentration is too low, when passing through the flue gas connection path 5, a supplementary combustion device 6 is needed to further increase the flue gas temperature. At this time, the cold air containing low-concentration methane is heated to 510 °C after heat exchange in the gas-gas heat exchanger 4 and enters Reactor 1 through the hot air path 7 for reaction. In this example, a tubular gas-gas heat exchanger is used, and the heat exchanger uses a spiral groove tube with an inner diameter j of 42 mm. The methane content of the flue gas in the flue gas connection path 5 before the supplementary combustion device 6 is reduced by more than 90% compared with the air just entering Reactor 1.

[0038] The above is an overall layout scheme of a reaction device for treating low-concentration methane in coal mine exhaust air.

[0039] The basic example of the present application and its various further selected examples can be freely combined to form multiple embodiments, all of which are the embodiments that can be adopted and claimed in the present application. In the solution of the present application, each selected example can be arbitrarily combined with any basic example and selected example.

[0040] The above are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A reaction device for treating low-concentration methane in coal mine exhaust air, comprising a reactor (1), characterized in that: The upper part of the described reactor (1) is in communication with the separation device (2), the gas end of the separation device (2) is in communication with the flue gas connection passage (5), a supplementary combustion device (6) is provided on the flue gas connection passage (5), the flue gas connection passage (5) is in communication with the hot side passage of the gas-gas heat exchanger (4), the cold side passage of the gas-gas heat exchanger (4) is in communication with the hot air passage (7), and the hot air passage (7) is in communication with the lower part of the reactor (1).

2. The reaction device for treating low-concentration methane in coal mine exhaust air according to claim 1, characterized in that: The material end of the described separation device (2) is in communication with the recovery device (3), and the recovery device (3) is in communication with the lower part of the reactor (1).

3. The reaction device for treating low-concentration methane in coal mine exhaust air according to claim 1 or 2, characterized in that: The lower part of the described reactor (1) is provided with a feeding device (10), the bottom of the reactor (1) is provided with an ignition device (8) and a slag discharging device (9), and the ignition device (8) is located at the outlet of the hot air passage (7).

4. The reaction device for treating low-concentration methane in the exhaust air of coal mines according to claim 1, characterized in that: The interior of the described reactor (1) has a structure without equipment layout and / or a structure without heating surface layout.

5. The reaction device for treating low-concentration methane in the exhaust air of coal mines according to claim 1 or 4, characterized in that: The described reactor (1) is a reaction channel with a reaction time of at least 2 seconds.

6. The reaction device for treating low-concentration methane in the exhaust air of coal mines according to claim 1, wherein: The range of the particle size a of the material in the reactor (1) is 100μm ≤ a ≤ 800μm, the range of the flue gas velocity b in the reactor (1) is 4m / s ≤ b ≤ 6m / s, and the range of the height c of the reactor (1) is c > 2b.

7. The reaction device for treating low-concentration methane in coal mine exhaust air according to claim 1 or 6, characterized in that: The range of the inner diameter d of the described separation device (2) is 1m ≤ d ≤ 10m, the range of the net clearance height e at the inlet of the separation device (2) is 0.8d ≤ e ≤ 1.3d, the range of the minimum value f of the net clearance width at the inlet of the separation device (2) is 0.2d ≤ f ≤ 0.4d, and the range of the angle g of the lower cone section of the separation device is 70° ≤ g ≤ 80°.

8. The reaction device for treating low-concentration methane in the exhaust air of coal mines according to claim 2, characterized in that: The range of the height i at which the described recovery device (3) is connected to the furnace is 0.5m ≤ i ≤ 3.5m.

9. The reaction device for treating low-concentration methane in coal mine exhaust air according to claim 1, wherein: The type of the described gas-gas heat exchanger (4) is a tubular gas-gas heat exchanger or a rotary gas-gas heat exchanger; when the gas-gas heat exchanger (4) is selected as a tubular gas-gas heat exchanger, the heat exchanger tubes use spiral groove tubes, and the range of the inner diameter j of the heat exchanger tubes is 30mm ≤ j ≤ 60mm.

10. The reaction device for treating low-concentration methane in the mine exhaust air according to claim 3, characterized in that: The range of the feeding height h of the described feeding device (10) is 0.5m ≤ h ≤ 3m.

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