Spray gun for powder denitration agent

Abstract

The utility model relates to a spray gun for a powder denitration agent, which comprises a gun body, a packing box, a packing gland, a control gate valve, a short connecting pipe, a spray gun blowing air branch pipe, an emptying short pipe, a conveying pipeline, a conveying pipeline blowing air branch pipe and a branch stop valve, the side wall of the conveying pipeline is connected with a conveying pipeline blowing air branch pipe, the side wall of the short connecting pipe is communicated with a spray gun blowing air branch pipe and an emptying short pipe, the other end of the short connecting pipe is connected with a control gate valve, the control gate valve is connected with a gun body, a packing box and a packing gland are arranged at the rear end of the gun body, and a plurality of material outlets are formed in the front end of the gun body. And the front end of the gun body is inserted into a flue or a hearth. According to the utility model, the powder denitration agent spray gun is inserted into the flue gas under pressure under the condition that the device is not shut down, so that the dispersion uniformity of the powder denitration agent is improved, the reaction contact area is increased, and the denitration efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial flue gas purification devices, in particular to a spray gun for a powder denitrification agent. Background Art

[0002] Currently, the main back-end denitrification technologies used in industry are selective catalytic reduction (SCR), selective non-catalytic reduction (SNCR), and combined SCR+SNCR. All three technologies use liquid amino-based reducing agents, primarily liquid ammonia, aqueous ammonia, and urea solutions. In recent years, the use of powdered denitrification agents for industrial flue gas denitrification has been increasing. These include PNCR denitrification using polymeric denitrification agents and SNAR denitrification using solid non-amino-based reducing agents.

[0003] The powder denitrification agent spray gun is a key piece of equipment in denitrification processes using powder denitrification agents. The spray guns used for SCR and SNCR technologies are high-pressure atomizing spray guns used to disperse liquid materials. Directly using existing high-pressure atomizing spray guns to spray solid denitrification agents will cause material blockage. The use of pneumatic conveying technology to spray solid bulk materials into reaction systems has been widely used in the metallurgical industry. However, there is a certain difference between the particle size of the particles sprayed in the metallurgical industry and the particle size of the solid denitrification agents. Furthermore, the metallurgical industry sprays a gas-solid two-phase flow into a liquid environment such as molten steel, while the spraying of powder denitrification agents sprays the gas-solid two-phase flow into the flue gas. Polymer denitrification technology uses a single-tube spray gun, which delivers the polymer powder denitrification agent into the furnace through a nozzle. The nozzle outlet extends into a portion of the furnace, and cooling measures are required to prevent the polymer denitrification agent from adhering to the pipe nozzle due to heat and clogging the pipe nozzle. Unlike polymer denitrifiers, the powdered denitrifier used in SNAR denitrification technology does not adhere to the inner wall of the spray gun due to heat. Instead, it uses dilute-phase pneumatic conveying to deliver trace amounts of denitrifier powder (with a feed-gas ratio less than 1) into the flue gas, where it rapidly decomposes into reducing gases, achieving denitrification. The dispersion of the powdered denitrifier in the flue gas significantly impacts the denitrification effect. Therefore, spray guns that directly utilize liquid denitrifiers, those used in the metallurgical industry, and those used in PNCR denitrification technology cannot achieve uniform spraying of trace amounts of powdered denitrifier within the flue. Furthermore, petrochemical plants often operate continuously, shutting down for maintenance every few years. Industrial boiler flue gas is often pressurized and high-temperature. Therefore, the cost of shutting down the plant to insert a spray gun when implementing denitrification technology using powdered denitrifiers is significant and sometimes even impossible.

[0004] The degree of contact between the powdered denitrifier and the flue gas significantly affects denitrification efficiency. Furthermore, for industrial equipment containing pressurized, high-temperature flue gas, the spray gun must be able to be plugged in and out without shutting down the equipment. Currently, no spray gun can directly achieve this. Therefore, it is necessary to propose a new spray gun for powdered denitrifiers to address this issue. Utility Model Content

[0005] The purpose of the utility model is to provide a spray gun for a powder denitrification agent, which can be inserted into pressurized high-temperature flue gas or the spray gun can be replaced without stopping the device, and the uniformity of the powder denitrification agent dispersion can be improved, the reaction contact area can be increased, and the denitrification efficiency can be improved.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] The utility model discloses a spray gun for a powder denitrification agent, comprising a gun body, a packing box, a packing gland, a control gate valve, a short connecting pipe, a spray gun purge air branch pipe, an exhaust short pipe, a conveying pipeline, a conveying pipeline purge air branch pipe, and a branch cut-off valve. The branch cut-off valve is adjacent to a branch of the conveying pipeline and is connected to the short connecting pipe through a section of the conveying pipeline. The side wall of the conveying pipeline is connected to the conveying pipeline purge air branch pipe. The side wall of the short connecting pipe is communicated with the spray gun purge air branch pipe and the exhaust short pipe. The other end of the short connecting pipe is connected to the control gate valve, and the control gate valve is connected to the gun body. The rear end of the gun body is provided with a packing box and a packing gland, the front end of the gun body is provided with multiple material outlets, and the front end of the gun body is inserted into a flue or a furnace.

[0008] Preferably, the branch shut-off valve is located on the delivery pipeline after the branch, close to the branch position.

[0009] Preferably, the angle between the center plane of the spray gun purge air branch pipe and the exhaust short pipe is 90°~180°.

[0010] Preferably, the packing box and the packing gland are sleeved on the outer wall of the gun body.

[0011] Preferably, the gun body, control gate valve, short pipe, delivery pipeline, and branch shut-off valve are all connected by flanges.

[0012] Preferably, the packing gland may be welded to the gun body or may not be welded.

[0013] Preferably, the flange at the front end of the packing box is connected to the flange of a valve or short pipe installed on the furnace or flue opening, the packing box contains packing, and the flange at the rear end of the packing box is connected to the flange of the packing gland.

[0014] Preferably, the front end of the gun body is sealed with a blind plate, and the openings in the center of the blind plate and the side wall of the front end of the gun body serve as discharge ports.

[0015] The beneficial effects of the utility model are as follows:

[0016] 1. The utility model utilizes the packing gland to compress the packing in the packing box to fix the spray gun and prevent leakage of pressurized high-temperature flue gas, so that the spray gun can be inserted and removed from the pressurized high-temperature flue gas without stopping the device.

[0017] 2. The utility model realizes uniform dispersion of trace reducing agent powder and improves denitration efficiency by sealing the blind plate at the front outlet of the spray gun body and opening a certain number of holes in the blind plate and the side wall of the gun body as discharge ports. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a spray gun for a powder denitrification agent according to the present invention;

[0019] Figure 2 This is a schematic structural diagram of a spray gun for powder denitrification agent without a delivery pipeline and a purge air branch pipe according to the utility model;

[0020] Figure 3 It is a structural diagram of the front end of the spray gun;

[0021] Figure 4 This is the structural diagram of the packing box;

[0022] Figure 5 This is the structural diagram of the packing gland;

[0023] Figure 6 Schematic diagram of the spray gun opening with three rows of holes evenly distributed;

[0024] Figure 7 Schematic diagram of the spray gun opening with three rows of holes and two adjacent rows of holes offset by 60 degrees;

[0025] Figure 8 Schematic diagram of the spray gun openings with two rows of holes arranged at a 60° angle.

[0026] In the above figures, 1. gun body; 2. packing box; 201. opening short-circuit connecting flange; 202. packing box gland connecting flange; 3. packing gland; 4. control gate valve; 5. short pipe; 6. spray gun purge air branch pipe; 7. exhaust short pipe; 8. delivery pipeline; 9. delivery pipeline purge air branch pipe; 10. branch shut-off valve; 11. flue or furnace; 12. opening short-circuit valve; 13. packing. DETAILED DESCRIPTION

[0027] Below will be combined with the accompanying drawings of the present utility model, Figures 1 to 8 , clearly and completely illustrate the present invention. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Directional terms mentioned in the embodiments, such as up, down, front, and back, are only used with reference to the directions in the accompanying drawings and are used to illustrate, not to limit, the present invention.

[0028] First embodiment:

[0029] Refer to the attached Figures 1 to 8The utility model is a spray gun for powder denitrification agent, comprising a gun body 1, a packing box 2, a packing gland 3, a control gate valve 4, a short pipe 5, a spray gun purge air branch 6, an exhaust short pipe 7, a conveying pipeline 8, a conveying pipeline purge air branch 9, a branch cut-off valve 10 and a packing 13. The branch cut-off valve 10 is adjacent to the branch of the conveying pipeline and is connected to the short pipe 5 through a section of the conveying pipeline 8. The side wall of the conveying pipeline 8 is connected to the conveying pipeline purge air branch 9. The side wall of the short pipe 5 is connected to the spray gun purge air branch 6 and the exhaust short pipe 7. The other end of the short pipe 5 is connected to the control gate valve 4, and the control gate valve 4 is connected to the gun body 1. The rear end of the gun body 1 is provided with a packing box 2 and a packing gland 3. The front end of the gun body 1 is provided with multiple material outlets. The front end of the gun body 1 is inserted into the flue or furnace 11.

[0030] Preferably, the branch shut-off valve 10 is located on the branched delivery pipeline 8, close to the branch position. When there are multiple outlet areas, branch pipelines will be set up, and the branch shut-off valve 10 can control the activation and deactivation of the branch pipelines.

[0031] Preferably, the delivery pipe purge air branch 9 can be eliminated for a delivery pipe 8 less than 0.5 m in length. In a further optimized solution, the delivery pipe 8 is 1 m long, and the side wall of the delivery pipe 8 is connected to the delivery pipe purge air branch 9, which can purge the material accumulated in the delivery pipe 8 to prevent the delivery pipe 8 from being blocked.

[0032] Preferably, the center-plane angle between the spray gun purge air branch 6 and the exhaust short pipe 7 is 90° to 180°. A further optimization solution is to install the spray gun purge air branch 6 and the exhaust short pipe 7 at a 90° center-plane angle. The spray gun purge air branch 6 can purge accumulated material from the gun body 1 to prevent clogging. The exhaust short pipe 7 is used to confirm whether the spray gun is discharging material.

[0033] Preferably, the packing box 2 and the packing gland 3 are sleeved on the outer wall of the gun body 1 .

[0034] Preferably, the gun body 1, the control gate valve 4, the short pipe 5, the delivery pipe 8, and the branch shut-off valve 10 are all connected by flanges. The flange connection facilitates disassembly and is conducive to the maintenance and replacement of various components of the spray gun.

[0035] Preferably, the packing gland 3 can be welded to the gun body 1 or not. When the packing gland 3 is welded to the gun body, the spray gun insertion depth is fixed. When the packing gland 3 is not welded to the gun body 1, the spray gun insertion depth can be adjusted. A further optimization solution is to weld the packing gland 3 to the gun body 1.

[0036] Preferably, the front flange 201 of the packing box 2 is connected to the flange of the short-circuit valve 12 or its connecting short pipe opening in the flue or furnace 11, and the rear flange 202 of the packing box 2 is connected to the flange of the packing gland 3. Packing 13 is wrapped around the inner wall of the packing box 2. During the connection between the rear flange 202 of the packing box 2 and the flange of the packing gland 3, the packing 13 is compressed to secure the spray gun and prevent smoke leakage. In a further optimization solution, the packing 13 is graphite packing.

[0037] Preferably, the front end of the gun body 1 is sealed with a blind plate, and the center of the blind plate and the side wall of the gun body 1 are opened as discharge ports. The opening method is determined according to the diameter of the gun body 1 and the size of the flue or furnace 11. The blind plate at the front end of the gun body 1 is opened with 1 to 3 holes, and the opening method of the side wall of the gun body 1 is generally divided into 3 rows of holes, the adjacent rows of holes in the 3 rows are staggered by 60 degrees, and the holes in the 2 rows are staggered by 60 degrees. Figure 6 The three rows of holes are evenly distributed, as shown in Figure 7 The following figure shows three rows of holes with two adjacent rows of holes staggered 60 degrees. Figure 8 The figure shows two rows of holes arranged at a 60° angle with a staggered spacing. A further optimized solution is to open one hole in the front blind plate of the gun body 1 and to arrange the holes in the side wall of the gun body 1 in three rows with equal spacing.

[0038] Second embodiment:

[0039] The difference between this embodiment and the first embodiment is that: Figure 2 As shown, the delivery pipe 8 is less than 0.5m long, and the sidewall of the delivery pipe 8 is not connected to the delivery pipe purge air branch 9. The center plane angle between the spray gun purge air branch 6 and the exhaust short pipe 7 is 180°. The packing gland 3 is not welded to the gun body 1. The packing 13 is made of carbon fiber packing. The front blind plate of the gun body 1 has two holes, and the sidewall holes of the gun body 1 are arranged in two rows with a 60° angle.

[0040] The working principle of this utility model is as follows:

[0041] After a hole is opened in the flue or furnace, a short circuit and valve are installed, or a short pipe is connected after the valve to prevent flue gas leakage. The front end of the spray gun body is sealed with a blind plate. The side walls of the gun body are perforated in a specific pattern. The front end of the gun body is inserted a certain distance into the flue or furnace, and these holes serve as the spray gun's discharge port. The packing is wrapped in a packing box, and the flange of the packing gland is connected to the flange at the rear end of the packing box. During the tightening process, the packing gland compresses the packing, securing the spray gun and preventing flue gas leakage in the flue or furnace. The packing box and packing gland enable online insertion and removal of the spray gun. A branch shut-off valve controls the activation and deactivation of the branch line. The spray gun purge air branch can purge accumulated material from the gun body to prevent clogging. The short exhaust pipe can be used to confirm whether the spray gun discharge is unobstructed.

[0042] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various improvements and modifications to the technical solutions of the present invention made by ordinary technicians in this field should fall within the scope of protection determined by the claims of the present invention.

Claims

1. A spray gun for powder denitrification agent, characterized in that: Including gun body, packing box, packing gland, control gate valve, short pipe, spray gun purge air branch pipe, short exhaust pipe, delivery pipeline, delivery pipeline purge air branch pipe, branch shut-off valve; The branch shut-off valve is adjacent to the branch of the conveying pipeline and is connected to a short pipe through a section of the conveying pipeline. The side wall of the conveying pipeline is connected to the purge air branch of the conveying pipeline. The side wall of the short pipe is connected to the spray gun purge air branch and the exhaust short pipe. The other end of the short pipe is connected to the control gate valve, and the control gate valve is connected to the gun body. The rear end of the gun body is provided with a packing box and a packing gland, and the front end of the gun body is provided with multiple material outlets. The front end of the gun body is inserted into the flue or furnace.

2. A spray gun for powder denitrification agent according to claim 1, characterized in that: The branch cut-off valve is located on the delivery pipeline after the branch, close to the branch position.

3. A spray gun for powder denitrification agent according to claim 1, characterized in that: The central plane angle between the spray gun purge air branch pipe and the exhaust short pipe is 90°~180°.

4. A spray gun for powder denitrification agent according to claim 1, characterized in that: The packing box and the packing gland are sleeved on the outer wall of the gun body.

5. The spray gun for powder denitrification agent according to claim 1, characterized in that: The gun body, the control gate valve, the short pipe, the delivery pipeline and the branch cut-off valve are all connected by flanges.

6. The spray gun for powder denitrification agent according to claim 1, characterized in that: The flange at the front end of the packing box is connected to the flange of a valve or short pipe installed on the furnace or flue opening. The packing box contains packing, and the flange at the rear end of the packing box is connected to the flange of the packing gland.

7. The spray gun for powder denitrification agent according to claim 1, characterized in that: The front end of the gun body is sealed with a blind plate, and the openings in the center of the blind plate and the side wall of the front end of the gun body serve as discharge ports.

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