Unpowered SCR exhaust gas purification system for explosion-proof diesel engines in underground coal mines

Abstract

This invention discloses a non-powered SCR exhaust gas purification system for explosion-proof diesel engines in coal mines, belonging to the technical field of mining diesel engine exhaust gas purification systems. It utilizes the gravity of the urea aqueous solution and relies on a needle valve control component to ensure a stable supply of liquid into the spray throat via the connecting pipe. During operation, the supply of urea aqueous solution can be adjusted as needed by the liquid level in the float liquid controller. The combustion gases discharged from the diesel engine combustion chamber vaporize the urea aqueous solution. After mixing with the gaseous urea aqueous solution, an oxidation and neutralization reaction occurs, reducing acidic nitrogen oxides in the exhaust gas to weakly alkaline salts. After passing through an explosion-proof flame arrester for flame arrest and cooling, the system achieves the purpose of non-powered dry exhaust gas purification and emission, resulting in energy saving and environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of mining diesel engine tail gas purification systems, in particular to a non-powered dry tail gas exhaust system for realizing multi-stage explosion-proof and silencing in coal mines. Background Art

[0002] At present, industrialized coal mines require heavy equipment to participate in production. Diesel engines, as an important part of mechanical equipment, need to cope with the characteristics of high gas, high dust, high temperature and other characteristics of the underground coal mine environment. Therefore, underground explosion-proof diesel engines with the advantages of high efficiency, reliability and safety are widely used in ventilation, drainage, transportation and lifting operations in coal mines.

[0003] In view of the safety requirements in the gas environment of coal mines, the ambient air quality in the working area must be guaranteed to meet the working conditions of the on-site personnel. Therefore, the content of nitrogen oxides, carbon monoxide (CO), hydrocarbons (HC), (NOx) and soot particles (PM) in the exhaust emissions of diesel engines during operation must be lower than a certain concentration to ensure that there are no high irritating components in the tunnel. In view of this technical problem, SCR exhaust post-treatment technology can be used to solve the problem of diesel engine emission pollution in the mine. The exhaust gas of the diesel engine is purified by purifying the exhaust gas in the water washing box and eliminating the possible residual flame in the exhaust gas. However, the SCR urea used in conventional vehicle diesel engines currently requires a separate high-pressure pump with additional power, and it needs to cooperate with the on-board ECU electronic control system to force the injection of urea aqueous solution to achieve the purification of the exhaust gas. Therefore, this system and equipment are not suitable for the current underground explosion-proof diesel engine exhaust emission system. The layout of its power system puts forward certain requirements on working conditions such as limited space and underground electrical explosion-proof requirements, and its adaptability to the underground coal mine operation site is poor. Summary of the invention

[0004] This technology was invented to overcome the problems that the diesel engine exhaust purification system of the existing general-purpose vehicle SCR system technology needs to be independently equipped with an additional power-driven high-pressure pump and an ECU electronically controlled injection system, and the vehicles have poor adaptability to underground coal mine operations.

[0005] In view of at least one of the above technical problems, the present invention provides an unpowered SCR tail gas purification system for explosion-proof diesel engines in coal mines, which is applied to explosion-proof diesel engines used in coal mines with combustible gas environments. The tail gas of the diesel engine after entering the exhaust system is mixed with atomized urea aqueous solution after passing through a catalytic SCR aqueous solution injection pipe, and then discharged by oxidation and cooling, so as to achieve dry tail gas purification and emission below a certain temperature. The specific technical scheme is as follows:

[0006] The unpowered SCR exhaust purification system for explosion-proof diesel engines in underground coal mines includes:

[0007] A reaction liquid supply box, wherein a float liquid controller is provided below the reaction liquid supply box; a liquid injection channel is provided at the upper part of the reaction liquid supply box, and a cover is provided at the liquid injection channel; a liquid outlet is provided at the bottom of the reaction liquid supply box; a liquid replenishment port is provided at the top of the float liquid controller, and the liquid path of the liquid replenishment port is connected to the liquid outlet; the float liquid controller includes a needle valve control component, and the needle valve control component is used for the liquid replenishment port; the float liquid controller is provided with a height adjustment component;

[0008] A spraying throat, a communicating pipe is connected between the bottom of the float liquid controller and the middle of the spraying throat, and the communicating pipe is equipped with a control valve; one end of the spraying throat is connected to the exhaust port of the diesel engine, and the other end is connected to a muffler, and the outer end of the muffler is connected to an explosion-proof flame arrester.

[0009] In some embodiments of the present disclosure, the injection channel is an injection tube, and the cover is a one-way pressure relief sealing cover; the tube mouth of the injection tube is provided with an outer flange, and the outer flange is circumferentially provided with several bayonet holes; the one-way pressure relief sealing cover comprises a cover body, and the cover edge of the cover body is provided with a clip matched with the bayonet hole; a center rod is vertically provided on the inner surface of the cover body; the center rod is successively penetrated by a coil spring I, a breathable pressure cover, an elastic sealing sheet and a coil spring II from the root to the end, and a spring limiting assembly is provided at the end of the center rod; the projection of the tube mouth of the injection tube is inside the bottom surface of the breathable pressure cover, and the breathable pressure cover is provided with a breathable through hole in the area within the projection; the projection of the breathable through hole is inside the elastic sealing sheet, and the projection of the elastic sealing sheet is inside the tube mouth of the injection tube; the contact surface between the tube mouth of the injection tube and the breathable pressure cover is provided with a sealing member.

[0010] In some embodiments of the present disclosure, a sealing ring groove is provided on the outer side of the nozzle of the injection tube, and the sealing member is located in the sealing ring groove, and the sealing member is an O-ring.

[0011] In some embodiments of the present disclosure, the fluid inlet is a variable diameter channel that is larger at the bottom and smaller at the top; the float fluid controller includes a solution chamber; the needle valve control assembly includes a float and a valve needle, the float is arranged in the solution chamber, the valve needle is arranged on the upper part of the float, and the valve needle is a conical structure with a pointed top.

[0012] In some embodiments of the present disclosure, the variable diameter channel is a concentric stepped tube.

[0013] In some embodiments of the present disclosure, the communicating vessel pipeline includes an L-shaped pipeline I, the upper end of which is connected to the solution chamber, and the lower end of which is connected to the control valve in a threaded flange connection, wherein the bolt holes of one flange are long arc holes; the control valve is connected to the spraying throat through a matching pipeline II, and the pipe opening at the outer end of the pipeline II is perpendicular to the axis of the spraying throat.

[0014] In some embodiments of the present disclosure, a concentric variable-diameter curved inner throat is provided in the middle of the spray throat, the inner diameter of the curved inner throat gradually increases from the middle to both ends, and the pipe opening at the outer end of the pipeline II is lower than the axis of the spray throat.

[0015] In some embodiments of the present disclosure, a height adjustment assembly is provided on the left and right sides of the float liquid controller, and the height adjustment assembly includes a fixed plate, and the fixed plate supports an ear plate, and the inner side of the ear plate is fixedly connected to the outer side of the float liquid controller, and a bolt assembly is vertically connected between the ear plate and the fixed plate, and the ear plate is vertically provided with a threaded through hole, and the threaded through hole is equipped with a top screw acting on the upper surface of the fixed plate.

[0016] In some embodiments of the present disclosure, the silencer includes a silencer pipe having one end connected to the spray throat, the inner cavity of the silencer pipe is provided with two mutually parallel partitions and two mutually parallel silencer tubes, the two partitions are plate I and plate II, and the two silencer tubes are tube I and tube II; the partition is perpendicular to the axis of the silencer pipe, and the silencer tube is parallel to the axis of the silencer pipe; hole I is provided on plate I, and hole II is provided on plate II; one end of tube I is connected to plate I, and the other end extends out of hole II; one end of tube II is connected to plate II, and the other end extends out of hole I; the other end of the silencer pipe is connected to the explosion-proof flame arrester.

[0017] In some embodiments of the present disclosure, the explosion-proof flame arrester includes a flame arrester tube, and a corrugated flame arrester filter element is disposed in the flame arrester tube. The width of the fire filtering gap of the corrugated flame arrester filter element is 1 to 2 mm, and the length is 40 to 300 mm.

[0018] Compared with the prior art, the above-mentioned coal mine underground explosion-proof diesel engine unpowered SCR exhaust purification system has the following beneficial effects:

[0019] The supply of the urea aqueous solution in the present invention does not require the cooperation of an external power source. The gravity of the urea aqueous solution itself is relied on by the needle valve control component to ensure the stable supply of the liquid entering the spraying throat from the communicating pipe. The supply amount of the urea aqueous solution in the working state can be adjusted as needed by the liquid level height in the float liquid controller. The combustion gas discharged from the combustion chamber of the diesel engine realizes the vaporization of the urea aqueous solution. After the gas is mixed with the gaseous urea aqueous solution, an oxidation neutralization reaction occurs. The acidic nitrogen oxides in the tail gas are reduced to weakly alkaline salts. After the explosion-proof flame arrester is used to block the fire and reduce the temperature, the purpose of dry tail gas purification and emission is achieved, which is energy-saving and environmentally friendly.

[0020] The urea aqueous solution of this system is easy to replenish, and the start and stop of the system can be directly controlled by the control valve according to the on-site conditions. The operation method is simple, and there is no need for a lot of additional training on how to use it for operators.

[0021] The structure of the design is intuitive, without complicated mechanical transmission coordination and precision parts. It is suitable for working environments with poor sanitary conditions underground, has a high degree of adaptability to underground diesel engines, and is easy to promote and use immediately;

[0022] The explosion-proof power exhaust device can be equipped on diesel engine trackless rubber-wheeled transport vehicles, underground diesel generators and other equipment in underground gas explosion environments, and provides new technical inspiration for the purification method of the exhaust purification system of underground coal mine equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the general assembly structure of Example 3 of the present invention;

[0024] Figure 2 is a cross-sectional schematic diagram of the reaction liquid supply box in Example 3;

[0025] Figure 3 is a cross-sectional schematic diagram of the cover member in Example 3;

[0026] Figure 4 is a cross-sectional schematic diagram of the closed-circuit state of the needle valve control assembly in Example 3;

[0027] Figure 5 is a cross-sectional schematic diagram of the passage state of the needle valve control assembly in Example 3;

[0028] Figure 6 This is an exploded schematic diagram of the connection between pipeline I and the control valve thread flange in Example 3;

[0029] Figure 7 It is a partial cross-sectional schematic diagram of the spraying throat in Example 3;

[0030] Figure 8 A partial cross-sectional view of the muffler in Example 3

[0031] Fig. 9 A partial cross-sectional schematic diagram of the explosion-proof flame arrester in Example 3

[0032] Fig.10 It is a partial cross-sectional schematic diagram of the corrugated fire-blocking filter element in Example 3;

[0033] Explanation of the numbers in the figure: 1. Reaction liquid supply box; 11. Liquid injection channel; 111. Outer flange; 2. Float liquid controller; 21. Liquid filling port; 22. Needle valve control assembly; 221. Float; 222. Valve needle; 23. Height adjustment assembly; 231. Fixing plate; 232. Ear plate; 233. Bolt assembly; 234. Top screw; 24. Solution chamber; 3. Cover; 31. Cover body; 32. Center rod; 33. Coil spring I; 34. Breathable pressure cap ; 341. Air permeable hole; 35. Elastic sealing sheet; 36. Coil spring II; 37. Spring limit assembly; 38. Seal; 4. Spray throat; 41. Curved inner throat; 5. Connecting pipe; 51. Control valve; 52. Pipeline I; 53. Pipeline II; 6. Muffler; 61. Muffler pipe; 62. Plate I; 63. Plate II; 64. Cylinder I; 65. Cylinder II; 7. Explosion-proof flame arrester; 71. Flame arrester pipe; 72. Corrugated flame arrester filter element. DETAILED DESCRIPTION

[0034] In order to better understand the purpose, structure and function of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below.

[0035] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "provided with" and any variations thereof in this application are open-ended and are intended to cover non-exclusive inclusions.

[0036] The serial numbers assigned to the components herein are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" mentioned in this disclosure, unless otherwise specified, includes both direct and indirect "connections". In the description of this application, it should be understood that the directions or positional relationships indicated by the directional terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like are based on the attached Figure 1 The orientation or positional relationship in the use state shown is only for the convenience of description, and does not indicate or imply that the device or unit referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0037] As shown in the attached figure Figures 1 to 10As shown, an unpowered SCR exhaust purification system for explosion-proof diesel engines in coal mines is designed. When in use, it does not require a high-pressure pump, additional power, or an electronic control system to force the injection of urea aqueous solution. It can be used in coal mines with combustible gas working environments to achieve the purpose of neutralizing and purifying nitrogen oxides in diesel engine exhaust. It creates a basic working condition suitable for workers while ensuring the gas exchange capacity of the environment. The structure of the design is intuitive, without complicated mechanical transmission coordination and precision components. It is suitable for working environments with poor sanitary conditions underground, has a high degree of adaptability to underground diesel engines, and is easy to promote and use immediately. The system mainly includes:

[0038] A reaction liquid supply tank 1 for containing urea aqueous solution is provided. The reaction liquid supply tank 1 is arranged at a high place so that the urea aqueous solution inside can obtain sufficient potential energy. A float liquid controller 2 is provided below the reaction liquid supply tank 1. An injection channel 11 for replenishing urea aqueous solution is provided at the upper part of the reaction liquid supply tank 1. The injection channel 11 is provided with a cover 3. The inside of the reaction liquid supply tank 1 is in a non-airtight state so that the external atmospheric pressure can act on the urea aqueous solution inside the reaction liquid supply tank 1. A liquid outlet is provided at the bottom to facilitate the discharge of the urea aqueous solution; a liquid replenishing port 21 is provided at the top of the float liquid controller 2, and the liquid replenishing port 21 is connected to the liquid outlet; the float liquid controller 2 includes a needle valve control component 22, and the needle valve control component 22 is equipped with the liquid replenishing port 21; the float liquid controller 2 is equipped with a height adjustment component 23, which can adjust the overall height of the float liquid controller 2, so as to control the replenishment timing and replenishment amount of the urea aqueous solution and the volume of the urea aqueous solution in the float liquid controller 2 through the needle valve control component 22;

[0039] The spraying throat 4 is equipped with a communicating tube 5 between the bottom of the float liquid controller 3 and the middle of the spraying throat 4, forming an effect similar to a communicating tube. The communicating tube 5 is equipped with a control valve 51, which can control the on-off of the communicating tube 5 as needed; one end of the spraying throat 4 is connected to the exhaust port of the diesel engine, and the other end is connected to a muffler 6, and the outer end of the muffler 6 is connected to an explosion-proof flame arrester 7.

[0040] When ready for use, remove the cover 3, and inject urea aqueous solution into the reaction liquid supply tank 1 through the injection channel 11. The urea aqueous solution of the system is convenient to replenish. Since there is no liquid in the float liquid controller 2 to provide buoyancy for the float of the float liquid controller 2, the needle valve control component 22 is in a falling state, and the liquid replenishing port 21 forms a passage, so that the urea aqueous solution in the reaction liquid supply tank 1 enters the float liquid controller 2 to form water storage. The connection height of the float liquid controller 2 is adjusted by the height adjustment component 23, so that when the liquid level in the float liquid controller 2 is higher than the external port of the communicating vessel pipeline 5, the needle valve control component 22 floats up, blocks the liquid replenishing port 21, stops the liquid replenishment in the float liquid controller 2, and the system enters the standby state. When it is necessary to start exhaust gas treatment, open the control valve 51, and the urea aqueous solution can be sprayed out from the middle of the spraying throat 4 through the communicating vessel pipeline 5 according to the working principle of the communicating vessel, and the control valve can be directly controlled according to the on-site conditions. The system is easy to start and stop, and the operation method is simple. When using it, it does not require a lot of additional training on how to use it for the operators. The high-temperature exhaust gas sprayed by the diesel engine will atomize the urea aqueous solution and realize an oxidation neutralization reaction with it. Among them, the supply of the urea aqueous solution does not require the cooperation of an external power source. The gravity of the urea aqueous solution itself and the needle valve control component 22 ensure the stable supply of the urea aqueous solution entering the spray throat 4 from the communicating tube 5. The supply amount of the urea aqueous solution in the working state can be adjusted as needed by the liquid level height in the float liquid controller 2. The combustion gas discharged from the combustion chamber of the diesel engine realizes the vaporization of the urea aqueous solution. After the gas is mixed with the gaseous urea aqueous solution, an oxidation neutralization reaction occurs. The acidic nitrogen oxides in the exhaust gas are reduced to weakly alkaline salts. After the explosion-proof flame arrester 7 is used to block the fire and cool down, the purpose of dry exhaust gas purification and emission is achieved, which is energy-saving and environmentally friendly. When it is stopped, the control valve 51 is turned off, the communicating tube 5 can lose the working state of the communicating tube, and the infusion function is stopped.

[0041] This system can be equipped on explosion-proof power exhaust devices of diesel engine trackless rubber-wheeled transport vehicles, underground diesel generators and other equipment in underground gas explosion environments, and provides new technical inspiration for the purification method of exhaust gas purification systems of underground coal mine equipment.

[0042] In the above implementation mode, three embodiments are listed to implement the above technical solution. The reference to "embodiment" in this article means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. In the absence of conflict, the various embodiments in the present application can be combined with each other.

[0043] Embodiment 1 discloses an unpowered SCR tail gas purification system for an explosion-proof diesel engine in an underground coal mine. The system mainly includes:

[0044] A reaction liquid supply tank 1 is used for containing urea aqueous solution. The reaction liquid supply tank 1 can be an alkali-resistant container made of stainless steel or anti-corrosion engineering plastic. When in use, a tank body of different volumes is configured according to the actual vehicle model used. The reaction liquid supply tank 1 is set at a high place so that the urea aqueous solution inside can obtain sufficient potential energy. A float liquid controller 2 is provided below the reaction liquid supply tank 1; an injection channel 11 for replenishing urea aqueous solution is provided on the upper part of the reaction liquid supply tank 1. The injection channel 11 is equipped with a cover 3. The inside of the reaction liquid supply tank 1 is in a non-airtight state so that the external atmospheric pressure can Acting on the urea aqueous solution inside the reaction liquid supply tank 1; a liquid outlet is provided at the bottom of the reaction liquid supply tank 1 to facilitate the discharge of the urea aqueous solution; a liquid replenishment port 21 is provided at the top of the float liquid controller 2, and the liquid replenishment port 21 is connected to the liquid outlet; the float liquid controller 2 includes a needle valve control component 22, and the needle valve control component 22 is equipped with the liquid replenishment port 21; the float liquid controller 2 is equipped with a height adjustment component 23, which can adjust the overall height of the float liquid controller 2, so as to control the replenishment timing and replenishment amount of the urea aqueous solution and the volume of the urea aqueous solution in the float liquid controller 2 through the needle valve control component 22;

[0045] The spraying throat 4, a communicating tube 5 is connected between the bottom of the float liquid controller 3 and the middle of the spraying throat 4, forming an effect similar to a communicating tube, and the communicating tube 5 is equipped with a control valve 51, which can control the on and off of the communicating tube 5 as needed; one end of the spraying throat 4 is connected to the exhaust port of the diesel engine, and the other end is connected to a muffler 6, and the outer end of the muffler 6 is connected to an explosion-proof flame arrester 7;

[0046] Among them, the injection channel 11 is the injection port, and the cover 3 is a breathable functional part covering the injection port, which can be a breathable membrane, and similarly it can also be a breathable valve, and the breathable functional part is used to realize the adjustment of the pressure difference between the inside and outside of the reaction liquid supply box 1; the liquid replenishment port 21 is a variable diameter channel with a larger bottom and a smaller top. In this embodiment, the liquid replenishment port 21 is a ball groove structure; the float liquid controller 2 includes a solution cavity 24, and the needle valve control assembly 22 includes a float 221 and a valve needle 222, the float 221 is arranged in the solution cavity 24, and the valve needle 222 is arranged on the upper part of the float 221, and the valve needle 222 is a conical structure with a pointed top, and the side of the valve needle 222 cooperates with the inner wall of the liquid replenishment port 21, and the diameter of the root of the valve needle 222 is larger than the liquid replenishment cavity. The diameter of the port 21; the communicating vessel pipeline 5 includes an L-shaped pipeline Ⅰ52, the upper end of the pipeline Ⅰ52 is connected to the solution chamber 24, and the lower end of the pipeline Ⅰ52 is connected to the control valve 51 in a threaded flange connection; the explosion-proof flame arrester 7 includes a flame arrester tube 71, and a corrugated flame arrester filter element 72 is arranged in the flame arrester tube 71, and the width of the fire filtering gap of the corrugated flame arrester filter element 72 is 1mm and the length is 40mm; the system does not need to be separately configured with a high-pressure pump, additional power and an electronic control system to force the injection of urea aqueous solution, and can be applied to explosion-proof diesel engines used in coal mines with combustible gases. It completely abandons the existing water washing box exhaust gas purification and wet exhaust gas purification and explosion-proof systems that eliminate possible residual flames in the exhaust gas.

[0047] Embodiment 2 discloses an unpowered SCR exhaust purification system for an explosion-proof diesel engine in an underground coal mine. The difference between this embodiment and embodiment 1 is that the injection channel 11 is an injection pipe, and the cover 3 is a one-way pressure relief sealing cover; the pipe mouth of the injection pipe is provided with an outer flange 111, and the outer flange 111 is circumferentially provided with several bayonet holes; the one-way pressure relief sealing cover comprises a cover body 31, and the cover edge of the cover body 31 is provided with a clip for use with the bayonet hole; a center rod 32 is vertically provided on the inner surface of the cover body 31; the center rod 32 is successively penetrated with a coil spring I 33, a breathable pressure cover 34, an elastic sealing sheet 35 and a coil spring II 36 from the root to the end, and a spring limit assembly 37 is provided at the end of the center rod 32; the projection of the pipe mouth of the injection pipe is located in the breathable The inside of the bottom surface of the pressure cover 34, and the air-permeable pressure cover 34 is provided with an air-permeable through hole 341 in the area within the projection; the projection of the air-permeable through hole 341 is located inside the elastic sealing sheet 35, and the projection of the elastic sealing sheet 35 is located inside the nozzle of the injection pipe; the elastic sealing sheet 35 can be a soft rubber sheet, and the contact surface between the nozzle of the injection pipe and the air-permeable pressure cover 34 is provided with a sealing member 38; when in use, align the clip with the clip mouth, press the cover body 31, and the coil spring I33 retracts. When the clip is lower than the height of the outer flange 111, screw the cover body 31 so that the clip and the lower surface of the outer flange 111 form a locking position to fix, thereby fixing the cover 3 to the reaction liquid supply tank 1. During the working process, the gradual reduction of the urea aqueous solution will cause the reaction When the pressure in the reaction liquid supply tank 1 drops and negative pressure occurs, affecting the normal liquid supply, the elastic sealing sheet 35 is deformed under the negative pressure condition to open the air permeable hole 341, and the gas is replenished into the reaction liquid supply tank 1 from the air permeable hole 341 to maintain the normal liquid supply pressure and avoid the urea aqueous solution from being unable to be discharged normally due to the seal; the liquid replenishment port 21 is a variable diameter channel with a larger bottom and a smaller top. In this embodiment, the liquid replenishment port 21 is a conical circular hole structure; the float liquid controller 2 includes a solution chamber 24, and the needle valve control assembly 22 includes a float 221 and a valve needle 222. The float 221 is arranged in the solution chamber 24, and the valve needle 222 is arranged on the upper part of the float 221. The valve needle 222 is a conical structure with a pointed top, and the side of the valve needle 222 is The inner wall of the inlet 21 is matched, and the diameter of the root of the valve needle 222 is larger than the diameter of the inlet 21; the communicating vessel pipeline 5 includes an L-shaped pipeline Ⅰ52, the upper end of the pipeline Ⅰ52 is connected to the solution chamber 24, and the lower end of the pipeline Ⅰ52 is connected to the control valve 51 in a threaded flange connection, and the bolt hole of the flange plate at the lower end of the pipeline Ⅰ52 is a circular arc long hole, and the circular arc long hole can be changed within a certain angle range to achieve fine adjustment of the angles at both ends; the control valve 51 is connected to the spraying throat 4 through the matching pipeline Ⅱ53, and the pipe opening at the outer end of the pipeline Ⅱ53 is perpendicular to the axis of the spraying throat 4, so as to ensure that the urea aqueous solution sprayed from the outer end of the pipeline Ⅱ53 contacts as much exhaust gas as possible, and at the same time, avoid exhaust gas from blowing into the pipeline Ⅱ53 as much as possible;The silencer 6 comprises a silencer pipe 61 with one end connected to the spraying throat pipe 4. The inner cavity of the silencer pipe 61 is provided with two mutually parallel partitions and two mutually parallel silencer tubes. The two partitions are plate I 62 and plate II 63, and the two silencer tubes are tube I 64 and tube II 65. The partition is perpendicular to the axis of the silencer pipe 61, and the silencer tube is parallel to the axis of the silencer pipe 61. The plate I 62 is provided with a hole I, and the plate II 63 is provided with a hole II. One end of the tube I 64 is connected to the Connected to the plate Ⅰ62, the other end extends out of the hole Ⅱ; one end of the tube Ⅱ65 is connected to the plate Ⅱ63, and the other end extends out of the hole Ⅰ; the other end of the muffler 61 is connected to the explosion-proof flame arrester 7, and the tube Ⅰ64 and the tube Ⅱ65 can also achieve the purpose of explosion relief and pressure reduction; the explosion-proof flame arrester 7 includes a flame arrester tube 71, and a corrugated flame arrester filter 72 is arranged in the flame arrester tube 71, and the width of the fire filtering gap of the corrugated flame arrester filter 72 is 1.8mm and the length is 100mm. ;

[0048] like Figures 1 to 10As shown, embodiment 3 discloses an unpowered SCR exhaust purification system for an explosion-proof diesel engine in an underground coal mine. The difference between this embodiment and embodiment 2 is that a sealing ring groove is provided on the outer side of the injection pipe orifice, and the sealing member 38 is in the sealing ring groove. The sealing member 38 is an O-ring, which can be a rubber ring; the liquid replenishing port 21 is a variable diameter channel with a larger bottom and a smaller top. In this embodiment, the liquid replenishing port 21 is a concentric stepped tube structure; the float liquid controller 2 includes a solution chamber 24, and the needle valve control assembly 22 includes a float 221 and a valve needle 222. The float 221 is arranged in the solution chamber 24, and the valve needle 222 is arranged on the upper part of the float 221. The valve needle 222 is a conical structure with a pointed top. 2 is matched with the inner wall of the inlet 21, and the diameter of the valve needle 222 is larger than the diameter of the small hole in the step hole of the inlet 21; the communicating vessel pipeline 5 includes an L-shaped pipeline Ⅰ52, the upper end of the pipeline Ⅰ52 is connected to the solution chamber 24, and the lower end of the pipeline Ⅰ52 is connected to the control valve 51 in a threaded flange connection, and the bolt hole of the front end flange of the control valve 51 is a circular arc long hole, and the circular arc long hole can be changed within a certain angle range to achieve fine adjustment of the angles at both ends; the control valve 51 is connected to the spraying throat 4 through the matching pipeline Ⅱ53, and the nozzle at the outer end of the pipeline Ⅱ53 is perpendicular to the axis of the spraying throat 4; the middle part of the spraying throat 4 is provided with a concentric variable diameter curved inner throat 41, and the inner The diameter size increases gradually from the middle to both ends. The pipe opening at the outer end of the pipeline II 53 is lower than the axis of the spraying throat 4. The structure of the curved inner throat 41 can form a narrow tube effect. The position of the SCR aqueous solution spraying port is the smallest, and the exhaust emission flow rate is the largest, so that the negative pressure in the high-speed gas movement process sucks out and atomizes the urea aqueous solution; the left and right sides of the float liquid controller 2 are respectively provided with a height adjustment component 23, and the height adjustment component 23 includes a fixing plate 231, which can be fixed on the frame of the equipment used in the diesel engine to form a positional association and fixation between the diesel engine and the system. The fixing plate 231 supports an ear plate 232, and the inner side of the ear plate 232 is fixedly connected to the outer side of the float liquid controller 2, which can be welded A bolt assembly 233 is vertically connected between the ear plate 232 and the fixed plate 231. The ear plate 232 is vertically provided with a threaded through hole, and the threaded through hole is equipped with a top screw 234 acting on the upper surface of the fixed plate 231. The top screws 234 on the left and right sides of the float liquid controller 2 can adjust the height and angle of the float liquid controller 2 as needed to ensure the service life of the needle valve control assembly 22 and the volume of the urea aqueous solution in the solution chamber 24; the plate Ⅰ62, the plate Ⅱ63, the cylinder Ⅰ64 and the cylinder Ⅱ65 are provided with a plurality of silencer holes, which can achieve the purpose of explosion relief and pressure reduction; the explosion-proof flame arrester 7 includes a flame arrester tube 71, and the flame arrester tube 71 is equipped with a corrugated flame arrester filter 72, which can be a corrugated plate structure, such as Fig.10As shown, the fire filtering gap of the corrugated fire-blocking filter element 72 has a width of 2 mm and a length of 300 mm.

[0049] It can be understood that the above description is only for illustrating the specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the disclosure scope of the present application.

Claims

1. The unpowered SCR tail gas purification system for explosion-proof diesel engines in coal mines is characterized by: include: A reaction liquid supply box (1), wherein a float liquid controller (2) is provided below the reaction liquid supply box (1); a liquid injection channel (11) is provided at the top of the reaction liquid supply box (1), and the liquid injection channel (11) is provided with a cover (3); a liquid outlet is provided at the bottom of the reaction liquid supply box (1); a liquid replenishment port (21) is provided at the top of the float liquid controller (2), and the liquid path of the liquid replenishment port (21) is connected to the liquid outlet; the float liquid controller (2) comprises a needle valve control component (22), and the needle valve control component (22) is used for the liquid replenishment port (21); height adjustment components (23) are provided on the left and right sides of the float liquid controller (2), and the height adjustment component (23) comprises a fixing plate (231), and the fixing plate (231) supports an ear plate (232). The inner side of the ear plate (232) is fixedly connected to the outer side of the float liquid controller (2); a bolt assembly (233) is vertically connected between the ear plate (232) and the fixed plate (231); the ear plate (232) is vertically provided with a threaded through hole; the threaded through hole is provided with a top screw (234) acting on the upper surface of the fixed plate (231); the liquid replenishing port (21) is a variable diameter channel with a larger lower portion and a smaller upper portion, and the variable diameter channel is a concentric stepped tube; the float liquid controller (2) comprises a solution chamber (24); the needle valve control assembly (22) comprises a float (221) and a valve needle (222); the float (221) is arranged in the solution chamber (24); the valve needle (222) is arranged on the upper portion of the float (221); the valve needle (222) is a conical structure with a pointed upper portion; A spraying throat (4), a communicating pipe (5) is connected between the bottom of the float liquid controller (3) and the middle of the spraying throat (4), the communicating pipe (5) is provided with a control valve (51), the control valve (51) is connected to the spraying throat (4) through a connecting pipe II (53), the pipe opening at the outer end of the pipe II (53) is perpendicular to the axis of the spraying throat (4); a concentric variable diameter curved inner throat pipe (41) is provided in the middle of the spraying throat (4), the inner diameter of the curved inner throat pipe (41) gradually increases from the middle to the two ends, the pipe opening at the outer end of the pipe II (53) is lower than the axis of the spraying throat (4); one end of the spraying throat (4) is connected to the exhaust port of the diesel engine, and the other end is connected to a muffler (6), the outer end of the muffler (6) is connected to an explosion-proof flame arrester (7).

2. The coal mine underground explosion-proof diesel engine unpowered SCR tail gas purification system according to claim 1 is characterized in that: The injection channel (11) is an injection tube, and the cover (3) is a one-way pressure relief sealing cover; the tube mouth of the injection tube is provided with an outer flange (111), and the outer flange (111) is provided with a plurality of bayonet holes in the circumferential direction; the one-way pressure relief sealing cover comprises a cover body (31), and the cover edge of the cover body (31) is provided with a clamp for matching with the bayonet hole; a center rod (32) is vertically provided on the inner surface of the cover body (31); the center rod (32) is penetrated with a coil spring I (33), a breathable pressure cover (34), an elastic sealing sheet (35) and Coil spring II (36), the end of the center rod (32) is provided with a spring limit assembly (37); the projection of the injection pipe opening is located inside the bottom surface of the breathable pressure cover (34), and the breathable pressure cover (34) is provided with a breathable through hole (341) in the area within the projection; the projection of the breathable through hole (341) is located inside the elastic sealing sheet (35), and the projection of the elastic sealing sheet (35) is located inside the injection pipe opening; the contact surface between the injection pipe opening and the breathable pressure cover (34) is provided with a sealing member (38).

3. The coal mine underground explosion-proof diesel engine unpowered SCR tail gas purification system according to claim 2 is characterized in that: A sealing ring groove is provided on the outside of the injection pipe opening, the sealing member (38) is located in the sealing ring groove, and the sealing member (38) is an O-type sealing ring.

4. The coal mine underground explosion-proof diesel engine unpowered SCR tail gas purification system according to claim 1, characterized in that: The communicating vessel pipeline (5) comprises an L-shaped pipeline I (52), the upper end of the pipeline I (52) being connected to the solution chamber (24), and the lower end of the pipeline I (52) being connected to the control valve (51) in the form of a threaded flange, wherein a bolt hole of one flange is a circular arc long hole.

5. The coal mine underground explosion-proof diesel engine unpowered SCR tail gas purification system according to claim 1, characterized in that: The silencer (6) comprises a silencer pipe (61) having one end connected to the spraying throat pipe (4); the inner cavity of the silencer pipe (61) is provided with two mutually parallel partitions and two mutually parallel silencer tubes, the two partitions are plate I (62) and plate II (63), and the two silencer tubes are tube I (64) and tube II (65); the partition is perpendicular to the axis of the silencer pipe (61), and the silencer tube is parallel to the axis of the silencer pipe (61); the plate I (62) is provided with a hole I, and the plate II (63) is provided with a hole II; one end of the tube I (64) is connected to the plate I (62), and the other end extends out of the hole II; one end of the tube II (65) is connected to the plate II (63), and the other end extends out of the hole I; the other end of the silencer pipe (61) is connected to the explosion-proof flame arrester (7).

6. The coal mine underground explosion-proof diesel engine unpowered SCR tail gas purification system according to claim 1, characterized in that: The explosion-proof flame arrester (7) comprises a flame arrester tube (71), wherein a corrugated flame arrester filter element (72) is arranged in the flame arrester tube (71), and the width of the fire filtering gap of the corrugated flame arrester filter element (72) is 1 to 2 mm, and the length is 40 to 300 mm.

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