A urea lance suitable for use in an SNCR system

Abstract

This utility model discloses a urea spray gun suitable for SNCR systems, including a nozzle component and a shell, a cooling sealing tube, an atomizing gas tube, and a urea solution delivery tube nested from the outside in. One end of the urea solution delivery tube has a liquid inlet, and one end of the atomizing gas tube has a first compressed air inlet. The other ends of both the urea solution delivery tube and the atomizing gas tube are connected to the nozzle component. One end of the cooling sealing tube is sealed to the atomizing gas tube and has a second compressed air inlet. One end of the shell is sealed to the cooling sealing tube and has a third compressed air inlet. The other ends of both the cooling sealing tube and the shell are open. The nozzle component is located inside the end of the cooling sealing tube. During the operation of the urea spray gun, compressed air is introduced into the atomizing gas tube, the shell, and the cooling sealing tube. This utility model features a compact structure, simple operation, and high stability, improving the urea spraying effect.

Description

Technical Field

[0001] This utility model relates to the field of waste incineration flue gas treatment technology, specifically to a urea spray gun suitable for SNCR systems. Background Technology

[0002] In existing waste incinerators, the urea spray guns in SNCR systems are generally arranged perpendicular to the flue gas direction. Firstly, this perpendicular arrangement causes the spray guns and nozzles to be worn by particulate impurities carried in the flue gas, resulting in damage and reduced service life. Secondly, most of the urea solution sprayed from the guns mixes with the flue gas near the gun outlet and is then carried into the subsequent horizontal flue gas duct. However, the horizontal duct contains heat exchange surfaces, causing the flue gas temperature to drop rapidly. Therefore, the reaction between the urea solution and flue gas in the horizontal duct misses the optimal reaction temperature, affecting denitrification efficiency and resulting in a high ammonia slip rate. Thirdly, the poor atomization effect of the spray guns prevents the urea solution from fully mixing with the flue gas, and the short effective mixing reaction range leads to a low final denitrification efficiency. Utility Model Content

[0003] The technical problem to be solved by this utility model is to overcome the shortcomings of existing urea spray guns, such as unreasonable arrangement, low atomization degree leading to insufficient mixing of urea solution and flue gas, easy wear and dust accumulation of nozzles, and high ammonia escape, and to provide a urea spray gun with compact structure, convenient operation, and high atomization degree suitable for SNCR system.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0005] A urea spray gun suitable for an SNCR system includes a nozzle component and a housing, a cooling sealing tube, an atomizing gas tube, and a urea solution delivery tube, which are nested from the outside to the inside. One end of the urea solution delivery tube has a liquid inlet, and one end of the atomizing gas tube has a first compressed air inlet. The other ends of both the urea solution delivery tube and the atomizing gas tube are connected to the nozzle component. One end of the cooling sealing tube is sealed to the atomizing gas tube, and a second compressed air inlet is located on its side. One end of the housing is sealed to the cooling sealing tube, and a third compressed air inlet is located on its side. The other ends of both the cooling sealing tube and the housing are open structures, and the nozzle component is located inside the end of the cooling sealing tube. During operation of the urea spray gun, compressed air is introduced into the housing, the atomizing gas tube, and the cooling sealing tube.

[0006] As a further improvement of this utility model, the other end of the outer shell is provided with a movable cover plate assembly; when the urea spray gun is running, the cover plate assembly is opened, and when the urea spray gun is stopped, the cover plate assembly is closed to cover the nozzle component.

[0007] As a further improvement of this utility model, the cover plate assembly includes a hinge seat, a spring, and a cover plate; an mounting block is provided on the inner side of the housing, and there is a gap between the mounting block and the outer wall of the cooling sealing pipe; one end of the spring is connected to the mounting block, and the other end of the spring is connected to the cover plate; the hinge seat is used to achieve hinge connection between the end of the housing and one end of the cover plate; when the urea spray gun is running, the compressed air in the housing and the cooling sealing pipe pushes the spring and the cover plate to move, so as to open the cover plate; when the urea spray gun stops running, the spring pulls the cover plate to reset, so as to block the nozzle component.

[0008] As a further improvement of this utility model, the cover plate is a double-door structure.

[0009] As a further improvement of this utility model, the outer periphery of the outer shell is provided with a mounting flange, which is sealed to the flue of the incinerator.

[0010] As a further improvement of this utility model, the mounting flange is installed at the top of the flue so that the urea spray gun is set vertically at the top of the flue, and the atomized urea solution comes into contact with the flue gas in the opposite direction.

[0011] As a further improvement of this utility model, the outer shell is made of silicon carbide material.

[0012] As a further improvement of this utility model, the nozzle component includes a primary mixing chamber and a nozzle, with multiple nozzles arranged around the side of the primary mixing chamber. The primary mixing chamber is connected to an atomizing air pipe, and the end of the urea solution delivery pipe is connected to the primary mixing chamber. After the urea solution and compressed air are primary mixed and atomized in the primary mixing chamber, they are sprayed out through the nozzle.

[0013] As a further improvement of this utility model, the cooling sealing tube and the primary mixing chamber form a secondary atomization chamber, and the atomized urea solution sprayed through the nozzle is mixed and atomized a second time with the compressed air of the cooling sealing tube in the secondary atomization chamber.

[0014] Compared with the prior art, the advantages of this utility model are:

[0015] 1. This utility model relates to a urea spray gun for SNCR systems. By connecting the urea solution delivery pipe and the atomizing gas pipe to the nozzle component, the urea solution is uniformly atomized before being sprayed into the flue of the incinerator. Simultaneously, a cooling sealing pipe and a shell are installed outside the atomizing gas pipe. Both the cooling sealing pipe and the shell have compressed air inlets at one end and open ends at the other, with the nozzle component located inside the end of the cooling sealing pipe. During operation, compressed cooling air is introduced into both the shell and the cooling sealing pipe, achieving dual cooling of the urea spray gun. This helps reduce the temperature near the nozzle component, preventing deformation and damage due to prolonged exposure to high temperatures, thus extending the service life of the urea spray gun. Furthermore, the compressed air introduced into the cooling sealing pipe can further atomize the urea solution sprayed from the nozzle component, improving the atomization degree.

[0016] 2. This utility model relates to a urea spray gun for SNCR systems. By installing a mounting block inside the housing, one end of a spring is connected to the mounting block, and the other end of the spring is connected to a cover plate located at the end of the housing. The cover plate is connected to the end of the housing via a hinged joint, thus achieving a double-door installation of the cover plate at the end of the housing. When the urea spray gun is running, compressed air in the housing and cooling sealing pipe pushes the spring and cover plate to open the cover plate, allowing the atomized urea solution in the nozzle assembly to be sprayed into the flue. When the urea spray gun stops operating, the compressed air supply ceases, the spring pulls the cover plate back to its original position, protecting the nozzle assembly inside the protective housing. This prevents wear on the nozzle from the complex high-temperature flue gas in the flue, extending the service life of the nozzle assembly. Simultaneously, the housing, made of silicon carbide, features high structural strength, excellent wear resistance, corrosion resistance, and high-temperature resistance, protecting the nozzle assembly from erosion and wear caused by high-temperature flue gas. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structural principle of the urea spray gun in a specific embodiment of this utility model;

[0018] Figure 2 This is a side view of the urea spray gun in a specific embodiment of the present utility model;

[0019] Figure 3 Figure (a) is a schematic diagram of the structure and principle of the cover plate in a specific embodiment of the present utility model, and Figure (b) is a schematic diagram of the cover plate in the closed state and the cover plate in the open state.

[0020] Figure 4 This is a schematic diagram of the nozzle component in a specific embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the arrangement of the urea spray gun in the flue in a specific embodiment of this utility model;

[0022] Legend: 1. Liquid inlet; 2. First compressed air inlet; 3. Second compressed air inlet; 4. Third compressed air inlet; 5. Hinge seat; 6. Spring; 7. Cover plate; 8. Outer shell; 9. Mounting block; 10. Mounting flange; 11. Urea solution delivery pipe; 12. Atomizing gas pipe; 13. Cooling sealing pipe; 14. Nozzle assembly; 141. Primary mixing chamber; 142. Nozzle; 143. Secondary atomizing chamber; 100. Urea spray gun; 200. Incinerator; 201. Flue. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0024] In the description of this utility model, it should be understood that the terms "side", "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Example

[0027] like Figure 1 , Figure 2 and Figure 3As shown, the urea spray gun of this utility model, applicable to an SNCR system, includes a nozzle component 14, and a housing 8, a cooling sealing tube 13, an atomizing air tube 12, and a urea solution delivery tube 11, which are nested from the outside to the inside. The rear end of the urea solution delivery tube 11 has a liquid inlet 1, and the rear end of the atomizing air tube 12 has a first compressed air inlet 2. The front ends of both the urea solution delivery tube 11 and the atomizing air tube 12 are connected to the nozzle component 14. The rear end of the cooling sealing tube 13 is sealed to the atomizing air tube 12, and a second compressed air inlet 3 is provided on the rear side of the cooling sealing tube 13. The rear end of the housing 8 is sealed to the cooling sealing tube 13, and a third compressed air inlet 4 is provided on the rear side of the housing 8. The other ends of both the cooling sealing tube 13 and the housing 8 are open structures, and the nozzle component 14 is located inside the end of the cooling sealing tube 13. During the operation of the urea spray gun, compressed cooling air is introduced into the outer casing 8, the atomizing air pipe 12, and the cooling sealing pipe 13 to atomize the urea solution and cool the urea spray gun. It can be understood that in practical applications, the urea solution delivery pipe 11 and the atomizing air pipe 12 can reciprocate within the cooling sealing pipe 13. The rear end of the cooling sealing pipe 13 is sealed and fixed to the rear end of the outer casing 8 to prevent the cooling sealing pipe 13 from falling off when the urea solution delivery pipe 11 and the atomizing air pipe 12 move.

[0028] In this embodiment, by connecting the urea solution delivery pipe 11 and the atomizing gas pipe 12 to the nozzle component 14, the urea solution is uniformly atomized before being sprayed into the flue of the incinerator. Simultaneously, a cooling sealing pipe 13 and a housing 8 are provided outside the atomizing gas pipe 12. Both the cooling sealing pipe 13 and the housing 8 have compressed air inlets at one end, and their other ends are open. The nozzle component 14 is located inside the end of the cooling sealing pipe 13. During the operation of the urea spray gun, cooling air is introduced into both the housing 8 and the cooling sealing pipe 13, achieving dual cooling of the urea spray gun. This also helps reduce the temperature near the nozzle component 14, preventing deformation and damage due to prolonged exposure to high temperatures, and extending the service life of the urea spray gun. Furthermore, the compressed air introduced into the cooling sealing pipe 13 can further atomize the urea solution sprayed from the nozzle component 14, improving the atomization degree.

[0029] like Figure 4 As shown, the nozzle component 14 includes a primary mixing chamber 141 and a nozzle 142. Multiple nozzles 142 are arranged around the side of the primary mixing chamber 141. The primary mixing chamber 141 is connected to the front end of the atomizing air pipe 12. The front end of the urea solution delivery pipe 11 is connected to the primary mixing chamber 141. After the urea solution and compressed air are primary mixed and atomized in the primary mixing chamber 141, they are sprayed out through the nozzles 142.

[0030] Furthermore, a secondary atomization chamber 143 is formed between the inner side of the front end of the cooling sealing pipe 13 and the outer side of the primary mixing chamber 141. The atomized urea solution sprayed through the nozzle 142 is mixed and atomized a second time with the compressed air of the cooling sealing pipe 13 in the secondary atomization chamber 143, further improving the atomization effect of the urea solution. Finally, a highly atomized fan-shaped spray is formed and sprayed into the flue of the waste incinerator to fully contact and react with the flue gas.

[0031] In this embodiment, the front end of the outer casing 8 is provided with a movable cover plate assembly. When the urea spray gun is running, the cover plate assembly is opened, and when the urea spray gun is stopped, the cover plate assembly is closed to cover the nozzle component 14.

[0032] like Figure 3 As shown, the cover assembly includes a hinge seat 5, a spring 6, and a cover plate 7. A mounting block 9 is provided inside the housing 8, with a gap between the mounting block 9 and the outer wall of the cooling sealing pipe 13 to allow for smooth flow of compressed air. One end of the spring 6 is connected to the mounting block 9, and the other end is connected to the cover plate 7. The hinge seat 5 is used to hinge the end of the housing 8 to one end of the cover plate 7. When the urea spray gun is running, the compressed air in the housing 8 and the cooling sealing pipe 13 pushes the spring 6 and the cover plate 7 to move, thus opening the cover plate 7. When the urea spray gun stops, the spring 6 pulls the cover plate 7 back to its original position to cover the nozzle component 14.

[0033] like Figure 3 As shown, cover plate 7 is a double-door structure. When cover plate 7 is opened, it will not affect the spraying of urea solution by nozzle component 14. It can be understood that during the operation of the urea spray gun, the pressure of compressed air is between 0.3MPa and 0.5MPa. Spring 6 is impacted by the compressed air in the outer casing 8, and spring 6 will extend to a certain extent. Cover plate 7 will be impacted by the compressed air in the cooling sealing pipe 13 and the atomized urea sprayed from nozzle component 14. Combined with the action of hinge seat 5, cover plate 7 will be forced open. Overall, due to the large impact force, cover plate 7 can rotate 90° without obstructing the spraying of urea solution by nozzle component 14. Furthermore, the contact surfaces of the two cover plates 7 are provided with mutually mating stepped surfaces. When cover plate 7 is closed, it minimizes the intrusion of flue gas into the urea spray gun. Although the cover plate 7 cannot completely seal the nozzle component 14 in the housing 8, the cover plate 7 can still block the flue gas to a certain extent, prevent the flue gas from directly washing the nozzle component 14, reduce the damage to the nozzle component 14, and also prevent dust accumulation on the nozzle component 14 to a certain extent.

[0034] In this embodiment, the outer shell 8 is made of silicon carbide material, which has high structural strength and good heat insulation effect in high-temperature environments, and can protect the cooling sealing pipe 13, the atomizing gas pipe 12 and the urea solution delivery pipe 11. The cover plate 7 can also be made of silicon carbide material to improve high temperature resistance, corrosion resistance and impact resistance, and enhance the protection of the nozzle component 14.

[0035] like Figure 1 As shown, the outer periphery of the outer casing 8 is provided with a mounting flange 10, which is sealed to the flue 201 of the incinerator 200.

[0036] like Figure 5 As shown, the mounting flange 10 is installed at the top of the flue 201 so that the urea spray gun 100 is set vertically at the top of the flue 201. The atomized urea solution comes into contact with the flue gas in the opposite direction to improve the mixing degree of urea and flue gas, so as to achieve full reaction of urea and flue gas in the optimal reaction range and control the ammonia escape rate from the source.

[0037] In this embodiment, the urea solution is first initially broken up through a small hole in the nozzle of the inlet 1, and then fully mixed with compressed air in the atomizing pipe 12 to form a highly atomized fan-shaped water mist. The atomization cross-section can be adjusted to fully overlap with the entire cross-section of the first flue 201 of the incinerator 200 by adjusting the orifice size of the urea solution delivery pipe 11, the compressed air pressure in the atomizing pipe 12, and the airflow, thereby achieving thorough mixing of the urea solution and flue gas. It is understood that in actual operation, the spray velocity of the atomized urea needs to be higher than the flue gas velocity to penetrate the flue gas, but it cannot be too high, as this would cause the droplets to impact the flue wall.

[0038] The above description is merely a preferred embodiment of this utility model. The protection scope of this utility model is not limited to the above embodiments. All technical solutions falling within the scope of this utility model's concept are protected. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A urea spray gun suitable for an SNCR system, characterized in that, The device includes a nozzle assembly (14) and, from the outside to the inside, a housing (8), a cooling and sealing pipe (13), an atomizing gas pipe (12), and a urea solution delivery pipe (11), which are nested sequentially. One end of the urea solution delivery pipe (11) has a liquid inlet (1), and one end of the atomizing gas pipe (12) has a first compressed air inlet (2). The other ends of both the urea solution delivery pipe (11) and the atomizing gas pipe (12) are connected to the nozzle assembly (14). One end of the cooling and sealing pipe (13) is tightly sealed to the atomizing gas pipe (12). The cooling sealing pipe (13) is sealed and connected to the cooling sealing pipe (13) with a second compressed air inlet (3) on the side. One end of the outer shell (8) is sealed and connected to the cooling sealing pipe (13), and the outer shell (8) has a third compressed air inlet (4) on the side. The other ends of the cooling sealing pipe (13) and the outer shell (8) are open structures, and the nozzle component (14) is located inside the end of the cooling sealing pipe (13). During the operation of the urea spray gun, compressed air is introduced into the outer shell (8), the atomizing air pipe (12) and the cooling sealing pipe (13).

2. The urea spray gun for an SNCR system according to claim 1, characterized in that, The other end of the housing (8) is provided with a movable cover assembly; when the urea spray gun is running, the cover assembly is opened, and when the urea spray gun is stopped, the cover assembly is closed to cover the nozzle component (14).

3. The urea spray gun for an SNCR system according to claim 2, characterized in that, The cover plate assembly includes a hinge seat (5), a spring (6), and a cover plate (7); the inner side of the outer shell (8) is provided with a mounting block (9), and there is a gap between the mounting block (9) and the outer wall of the cooling sealing pipe (13). One end of the spring (6) is connected to the mounting block (9), and the other end of the spring (6) is connected to the cover plate (7). The hinge seat (5) is used to realize the hinge connection between the end of the outer shell (8) and one end of the cover plate (7). When the urea spray gun is running, the compressed air in the outer shell (8) and the cooling sealing pipe (13) pushes the spring (6) and the cover plate (7) to move, so as to realize the opening of the cover plate (7). When the urea spray gun stops running, the spring (6) pulls the cover plate (7) to reset, so as to block the nozzle component (14).

4. The urea spray gun for an SNCR system according to claim 3, characterized in that, The cover plate (7) is a double door structure.

5. The urea spray gun for an SNCR system according to any one of claims 1 to 4, characterized in that, The outer periphery of the outer shell (8) is provided with a mounting flange (10), which is sealed to the flue (201) of the incinerator (200).

6. The urea spray gun for an SNCR system according to claim 5, characterized in that, The mounting flange (10) is installed on the top of the flue (201) so that the urea spray gun (100) is set vertically on the top of the flue (201) and the atomized urea solution comes into contact with the flue gas in the opposite direction.

7. The urea spray gun for an SNCR system according to any one of claims 1 to 4, characterized in that, The outer shell (8) is made of silicon carbide material.

8. The urea spray gun for an SNCR system according to any one of claims 1 to 4, characterized in that, The nozzle component (14) includes a primary mixing chamber (141) and nozzles (142). Multiple nozzles (142) are arranged around the side of the primary mixing chamber (141). The primary mixing chamber (141) is connected to the atomizing air pipe (12). The end of the urea solution delivery pipe (11) is connected to the primary mixing chamber (141). After the urea solution and compressed air are primary mixed and atomized in the primary mixing chamber (141), they are sprayed out through the nozzles (142).

9. The urea spray gun for an SNCR system according to claim 8, characterized in that, The cooling sealing tube (13) and the primary mixing chamber (141) form a secondary atomization chamber (143). The atomized urea solution sprayed through the nozzle (142) is mixed and atomized a second time with the compressed air of the cooling sealing tube (13) in the secondary atomization chamber (143).

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