High-speed jet spray gun for flue gas SNCR (selective non-catalytic reduction) denitration

Abstract

The utility model relates to the technical field of denitration equipment, and discloses a high-speed jet spray gun for flue gas SNCR denitration, which comprises a spray pipe, a spray head and a steam cylinder, the spray pipe comprises a liquid inlet section, an acceleration section, a transition section and an outlet section which are communicated in sequence, the outlet section is communicated with the spray head and comprises a second contraction section, a second throat part and a second expansion section, the steam cylinder is located on the outer side of the spray pipe, a steam cavity is formed between the steam cylinder and the spray pipe, a steam inlet is formed in the side face of the steam cylinder, and an air inlet communicated with the steam cavity is formed in the second expansion section. According to the scheme, the Laval spray pipe is arranged at the outlet of the spray pipe, so that the flow speed of the atomized denitration agent is further increased, and the flue gas denitration effect is guaranteed; the second expansion section, the air inlet and other structures are arranged to suck steam, it is guaranteed that the steam continuously flows to cool the spray pipe, and resources are saved; meanwhile, steam enters the second expansion section to preheat the atomized denitration agent.

Description

Technical Field

[0001] This utility model relates to the field of denitrification equipment technology, specifically to a high-speed jet spray gun for flue gas SNCR denitrification. Background Technology

[0002] SNCR (Synchronous Non-Combustion Reduction) denitrification technology is a process that reduces nitrogen oxides (NOx) to nitrogen and water by reacting them with ammonia, urea, or organic amine solutions sprayed at high temperatures. The SNCR denitrification spray gun is one of the core pieces of equipment in this technology. Its main function is to spray the denitrification agent solution into the furnace or exhaust gas, ensuring its reaction with NOx and reducing NOx emissions. The working principle and design of the spray gun must guarantee the uniformity of the spray and the high efficiency of the reaction.

[0003] Currently, SNCR denitrification spray guns basically adopt dual-fluid spray guns, that is, compressed air is used to break up and atomize the liquid. However, in practical applications, there are some technical bottlenecks that need to be solved. On the one hand, when the flow rate of compressed air is high, although it can provide sufficient power, it will result in a larger atomized droplet size, which cannot achieve the ideal fineness. The size of the droplet directly affects its diffusion effect in the furnace and the degree of mixing with the flue gas. A higher flow rate will result in a larger atomized droplet. Therefore, the flow rate of compressed air is usually low during liquid atomization to ensure the fineness of droplet dispersion. However, a lower flow rate will affect the fluid range, causing the denitrification agent to not be fully dispersed in the furnace, thus affecting the denitrification effect of the flue gas. Utility Model Content

[0004] The present invention aims to provide a high-speed jet spray gun for flue gas SNCR denitrification, so as to solve the problem that the current low spray gun flow rate affects the flue gas denitrification effect.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a high-speed jet spray gun for flue gas SNCR denitrification, comprising: a nozzle, a nozzle head, and a steam cylinder. The nozzle includes a liquid inlet section, an acceleration section, a transition section, and an outlet section connected in sequence. The outlet section is connected to the nozzle head. The acceleration section is used to increase the flow rate of the denitrification agent after atomization. The outlet section includes a second contraction section, a second throat, and a second expansion section. The second contraction section is connected to the transition section, and the second expansion section is connected to the nozzle. The steam cylinder is located outside the nozzle, and a steam chamber is formed between the steam cylinder and the nozzle. A steam inlet is provided on the side of the steam cylinder, and an air inlet connected to the steam chamber is provided on the second expansion section.

[0006] The principle of this scheme is as follows: After atomization, the denitrifying agent enters the inlet section, then is accelerated through the acceleration section, and then enters the transition section, finally entering the second contraction section. The atomized denitrifying agent enters the second contraction section from the transition section with a larger flow cross-section, and the flow rate of the atomized denitrifying agent increases. Then it enters the second throat, which is a key part of the Laval nozzle, controlling the maximum flow rate of the gas. The atomized denitrifying agent reaches its maximum velocity in the second throat. After the second throat, the diameter of the second expansion section increases, and the atomized denitrifying agent continues to expand and accelerate. The pressure in the second expansion section decreases, and steam enters the second expansion section under the action of external air pressure. The steam cools the nozzle and preheats the atomized denitrifying agent.

[0007] Advantages of this scheme: By setting a Laval nozzle at the nozzle outlet to further increase the flow rate of the atomized denitrification agent, the fluid range can be increased, allowing the denitrification agent to be fully dispersed in the furnace and react with the corresponding flue gas, ensuring the denitrification effect of the flue gas; at the same time, the denitrification agent can be quickly injected into the flue gas, accelerating the mixing process between the denitrification agent and the flue gas; the temperature inside the furnace is high, reaching 800℃, and by setting up structures such as the second expansion section and air inlet to draw steam, a continuous flow of steam is ensured to cool the nozzle, saving resources; at the same time, the steam entering the second expansion section preheats the atomized denitrification agent, allowing the denitrification agent to quickly reach the reaction temperature in the furnace and react with the flue gas, accelerating the denitrification speed of the flue gas.

[0008] Preferably, the acceleration section includes a first contraction section, a first throat, and a first expansion section, wherein the first expansion section and the transition section are connected. By setting the first contraction section, the first throat, and the first expansion section, a Laval nozzle structure is formed to accelerate the atomized denitrification agent and increase the fluid velocity.

[0009] Preferably, the steam inlet is located above the liquid inlet section.

[0010] Preferably, the second expansion section is provided with multiple air inlets, which are evenly distributed in a ring on the second expansion section. Providing multiple air inlets accelerates the speed at which steam enters the second expansion section.

[0011] Preferably, the air inlet is inclinedly disposed on the second expansion section.

[0012] Preferably, the inlet section is equipped with a plunger pump to pressurize the solution and enhance its penetrating power.

[0013] Preferably, a sealed steam chamber is formed between the steam cylinder and the nozzle. Forming a sealed steam chamber can reduce steam diffusion and loss, thus saving resources.

[0014] Preferably, the nozzle includes a spray plate with multiple nozzles evenly distributed on it, and the spray plate is positioned at the outlet of the second expansion section. By providing multiple nozzles to disperse the denitrification agent and guide its injection direction, the denitrification agent is more evenly distributed in the flue gas, increasing the contact area between the denitrification agent and the flue gas.

[0015] Preferably, the steam inlet is connected to the side wall of the steam cylinder with an arc-shaped transition. Sharp turns can cause airflow separation, eddies, and turbulence, thereby increasing resistance. The arc-shaped transition allows the airflow to flow smoothly from the inlet into the pipe, avoiding abrupt angle changes or sharp corners and reducing airflow resistance. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram of an embodiment of the present utility model. Detailed Implementation

[0017] The following detailed description illustrates the specific implementation method:

[0018] The reference numerals in the accompanying drawings include: nozzle 1, liquid inlet section 11, acceleration section 12, first contraction section 121, first throat 122, first expansion section 123, transition section 13, outlet section 14, second contraction section 141, second throat 142, second expansion section 143, air inlet 1431, nozzle 2, steam cylinder 3, and steam inlet 31.

[0019] Example:

[0020] A high-speed jet spray gun for flue gas SNCR denitrification, as shown in the attached image. Figure 1 As shown, it includes: a nozzle 1, a nozzle 2, and a steam cylinder 3. The nozzle 1 includes a liquid inlet section 11, an acceleration section 12, a transition section 13, and an outlet section 14 connected in sequence. Among them, the liquid inlet section 11 is equipped with a plunger pump, which pressurizes the solution to enhance the solution's penetration.

[0021] The acceleration section 12 is used to increase the flow rate of the atomized denitrification agent. The acceleration section 12 includes a first contraction section 121, a first throat 122, and a first expansion section 123, which is connected to the transition section 13. The diameters of the first contraction section 121 and the first expansion section 123 are both larger than the diameter of the first throat 122. By setting the first contraction section 121, the first throat 122, and the first expansion section 123, a Laval nozzle structure is formed to accelerate the atomized denitrification agent and increase the fluid velocity. The core function of the Laval nozzle is to convert the pressure and temperature energy of the gas into kinetic energy and the velocity of the airflow. The Laval nozzle includes a contraction section, a throat, and an expansion section. The contraction section is typically wider at the inlet and gradually narrows as the nozzle length increases. In this section, the airflow accelerates, the pressure and temperature gradually decrease, and the velocity gradually increases. Throat: The narrowest part of the nozzle. The throat is the core of the Laval nozzle and determines the velocity limit of the jet. The gas is fastest, at the lowest pressure and temperature when passing through the throat, and the airflow speed reaches the speed of sound here. Divergence section: The divergence section after the throat. The diameter of the nozzle gradually increases. Under ideal conditions, the airflow is further accelerated here, and the speed can break the speed of sound and reach supersonic speed.

[0022] The outlet section 14 is connected to the nozzle 2. The outlet section 14 includes a second contraction section 141, a second throat 142, and a second expansion section 143. The diameters of the second contraction section 141 and the second expansion section 143 are both larger than the diameter of the second throat 142. The second contraction section 141 is connected to the transition section 13, and the second expansion section 143 is connected to the nozzle. After atomization, the denitrifying agent enters the inlet section 11, and then is accelerated through the acceleration section 12. After acceleration, it enters the transition section 13, and finally enters the second contraction section 141. The atomized denitrifying agent enters the second contraction section 141, gradually contracting from the transition section 13 with a larger flow cross-section, and the flow rate of the atomized denitrifying agent increases. Then it enters the further contracting second throat 142. The throat is a key part of the Laval nozzle, controlling the maximum flow rate of the gas. The atomized denitrifying agent reaches its maximum velocity in the second throat 142. After the second throat 142, the diameter of the second expansion section 143 increases, and the atomized denitrifying agent continues to expand and accelerate. By setting a Laval nozzle at the outlet of nozzle 1 to further increase the flow rate of the atomized denitrifying agent, the range of the fluid can be increased, allowing the denitrifying agent to be fully dispersed in the furnace and react with the corresponding flue gas, ensuring the denitrification effect of the flue gas; at the same time, the denitrifying agent can be rapidly injected into the flue gas, accelerating the mixing process between the denitrifying agent and the flue gas. In this embodiment, the throat diameter of the Laval nozzle formed by the acceleration section 12 and the outlet section 14 is 4-10 cm, and the cone angle of the expansion section is within 10 degrees.

[0023] The steam cylinder 3 is located outside the nozzle 1, forming a steam chamber between the steam cylinder 3 and the nozzle 1. A steam inlet 31 is located on the side of the steam cylinder 3, above the liquid inlet section 11 and the acceleration section 12. An air inlet 1431 communicating with the steam chamber is located on the second expansion section 143. The pressure decreases at the second expansion section 143, and steam enters the second expansion section 143 under external air pressure. The steam cools the nozzle 1 and preheats the atomized denitrification agent. The temperature inside the furnace is high, reaching 800℃. By setting up the second expansion section 143 and the air inlet 1431, steam is drawn in, ensuring a continuous flow of steam to cool the nozzle 1 and conserve resources. Simultaneously, the steam entering the second expansion section 143 preheats the atomized denitrification agent, allowing it to quickly reach the reaction temperature and react with the flue gas, accelerating the denitrification speed.

[0024] The second expansion section 143 is provided with multiple air inlets 1431, which are evenly distributed in a ring on the second expansion section 143. By providing multiple air inlets 1431, the speed at which steam enters the second expansion section 143 is accelerated. The air inlets 1431 are inclinedly arranged on the second expansion section 143. The inner wall of each air inlet 1431 is machined with a spiral guide groove.

[0025] A sealed steam chamber is formed between the steam cylinder 3 and the nozzle 1. This sealed chamber reduces steam diffusion and loss, conserving resources. The steam inlet 31 is connected to the side wall of the steam cylinder 3 via an arc-shaped transition. Sharp turns can cause airflow separation, eddies, and turbulence, increasing resistance. The arc-shaped transition streamlines the connection, allowing airflow to flow smoothly from the inlet 1431 into the pipe, avoiding abrupt angle changes or sharp turns, thus significantly reducing airflow resistance.

[0026] The nozzle 2 includes a spray plate with multiple nozzles evenly distributed on it. The spray plate is positioned at the outlet of the second expansion section 143. By using multiple nozzles to disperse the denitrifying agent and guide its spray direction, the denitrifying agent is more evenly distributed in the flue gas, increasing the contact area between the agent and the flue gas. The nozzles are arranged concentrically or in a matrix on the spray plate. A concentric arrangement ensures uniform liquid distribution at different distances, particularly suitable for scenarios requiring uniform liquid distribution over a large area. A matrix arrangement ensures liquid reception in every area, guaranteeing effective denitrification in each region of the furnace. For example, a grid arrangement of nozzles can further enhance denitrification. The nozzles on the spray plate 2 are fan-shaped, allowing for more even liquid distribution over a large area, reducing missed or insufficient spraying areas. The size of the spray plate matches the diameter of the second expansion section 143.

[0027] The specific implementation process is as follows:

[0028] After atomization, the denitrifying agent enters the inlet section 11 and is pressurized by a plunger pump. Then, it is accelerated through the acceleration section 12, which consists of a first contraction section 121, a first throat 122, and a first expansion section 123. After acceleration, it enters the transition section 13 and finally the second contraction section 141. The atomized denitrifying agent enters the second contraction section 141 and enters the contraction section from the transition section 13, which has a larger flow cross-section, thus increasing the flow rate of the atomized denitrifying agent. Then, it enters the further contracted second throat 142, where the atomized denitrifying agent reaches its maximum velocity. After the second throat 142, the diameter of the second expansion section 143 increases, and the atomized denitrifying agent continues to expand and accelerate. The pressure at the second expansion section 143 decreases, and steam enters the second expansion section 143 under the action of external air pressure. The steam cools the nozzle 1 and preheats the atomized denitrifying agent. Finally, the atomized denitrifying agent is ejected from the nozzle of the spray plate.

[0029] This scheme forms a Laval nozzle structure by setting a first contraction section 121, a first throat 122, and a first expansion section 123 to accelerate the atomized denitrification agent and increase the fluid velocity. A Laval nozzle is set at the outlet of nozzle 1 to further increase the flow rate of the atomized denitrification agent, increase the fluid range, and ensure the denitrification effect of the flue gas. Simultaneously, the denitrification agent can be rapidly injected into the flue gas, accelerating the mixing process between the agent and the flue gas. Steam enters the second expansion section 143 to preheat the atomized denitrification agent, enabling it to quickly reach the reaction temperature in the furnace and react with the flue gas, accelerating the denitrification speed. At the same time, the second expansion section 143 and the air inlet 1431 are used to extract steam, saving resources.

[0030] The above descriptions are merely embodiments of this utility model, and common technical solutions and / or characteristics known in the scheme are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solution of this utility model. In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. The scope of protection claimed in this application shall be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A high-speed jet spray gun for SNCR denitrification of flue gas, characterized in that, include: The nozzle comprises a spray pipe, a nozzle, and a steam cylinder. The spray pipe includes a liquid inlet section, an acceleration section, a transition section, and an outlet section connected in sequence. The outlet section is connected to the nozzle. The acceleration section is used to increase the flow rate of the denitrifying agent after atomization. The outlet section includes a second contraction section, a second throat, and a second expansion section. The second contraction section is connected to the transition section, and the second expansion section is connected to the nozzle. The steam cylinder is located outside the spray pipe, and a steam chamber is formed between the steam cylinder and the spray pipe. A steam inlet is provided on the side of the steam cylinder, and an air inlet connected to the steam chamber is provided on the second expansion section.

2. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: The acceleration section includes a first contraction section, a first throat, and a first expansion section, wherein the first expansion section and the transition section are connected.

3. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: The steam inlet is located above the liquid inlet section.

4. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: The second expansion section is provided with multiple air inlets, which are evenly distributed in a ring on the second expansion section.

5. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: The air inlet is inclined and positioned on the second expansion section.

6. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: A plunger pump is installed on the inlet section.

7. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: A closed steam chamber is formed between the steam cylinder and the nozzle.

8. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 1, characterized in that: The nozzle includes a spray plate with multiple nozzles evenly distributed on it. The spray plate is located at the outlet of the second expansion section.

9. A high-speed jet spray gun for flue gas SNCR denitrification according to claim 8, characterized in that: The steam inlet is connected to the side wall of the steam cylinder in an arc transition.

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