High-speed jet spray gun system 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 system for flue gas SNCR (selective non-catalytic reduction) denitration, which comprises a dilution water tank, a denitration agent storage tank, a gas supply device, a mixing pipe, a plunger pump and a spray gun, the mixing pipe, the plunger pump and the spray gun are sequentially connected, the dilution water tank is communicated with the mixing pipe, and the communication position of the mixing pipe and the dilution water tank is positioned at the bottom of the dilution water tank. The denitration agent storage tank is communicated with the mixing pipe, the communication position of the mixing pipe and the denitration agent storage tank is located at the bottom of the denitration agent storage tank, and the gas supply device is used for carrying out beam pressurization on a denitration solution sprayed by the spray gun. According to the scheme, pressurization is conducted through the plunger pump, and the penetrating power of a solution is enhanced; the gas supply device is used for carrying out beam pressurization on the denitration mixed solution, the solution jet intensity is improved, meanwhile, the evaporation speed of high-temperature flue gas to the solution is reduced, and the denitration mixed solution and the flue gas are fully mixed for denitration.

Description

Technical Field

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

[0002] SNCR (Synchronous Non-Combustion Reduction) denitrification technology is a process that, under high-temperature conditions, reacts a denitrifying agent, such as ammonia, urea, or organic amine solution, with nitrogen oxides, reducing them to nitrogen and water. The SNCR denitrification spray gun is one of the core pieces of equipment in this technology. Its main function is to spray the denitrifying agent into the furnace or exhaust gas, ensuring the agent reacts with nitrogen oxides and reducing their emissions. The working principle and design of the spray gun must guarantee uniform spraying and high reaction efficiency.

[0003] Among current flue gas denitrification technologies, SNCR technology is widely used in the treatment of flue gas from coal-fired boilers due to its high efficiency and economy. Currently, SNCR denitrification nozzles mainly employ dual-fluid nozzles. Their working principle involves using compressed air to break up and atomize the denitrification solution, thereby achieving thorough mixing between the denitrifying agent and the flue gas. However, existing dual-fluid nozzles have several problems in practical applications. For example, it is difficult to balance the atomization intensity and stiffness of the nozzle. When the atomization effect is good, the nozzle stiffness is often insufficient, causing the spray shape to be easily disturbed by the airflow inside the furnace, making it impossible to form a stable spray cone angle. Conversely, when the nozzle stiffness is increased, the atomized particle size increases, affecting the contact area between the denitrifying agent and the flue gas. To ensure the atomization effect of the denitrifying agent, the intensity of the atomized liquid jet sprayed from the nozzle is usually relatively low. However, in large boilers, due to the large furnace cross-section, the intensity of the atomized liquid jet is limited, making it difficult for the denitrification solution to penetrate deep into the furnace, resulting in poor mixing between the denitrification solution and the flue gas, leading to low flue gas denitrification efficiency. Utility Model Content

[0004] The present invention aims to provide a high-speed jet spray gun system for flue gas SNCR denitrification, in order to solve the problem of poor mixing effect between denitrification solution and flue gas in large furnaces.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a high-speed jet spray gun system for flue gas SNCR denitrification, comprising: a dilution water tank, a denitrification agent storage tank, an air supply device, and a mixing pipe, a plunger pump, and a spray gun connected in sequence. The dilution water tank is connected to the mixing pipe, and the connection between the mixing pipe and the dilution water tank is located at the bottom of the dilution water tank. The denitrification agent storage tank is connected to the mixing pipe, and the connection between the mixing pipe and the denitrification agent storage tank is located at the bottom of the denitrification agent storage tank. The air supply device is used to pressurize the denitrification solution sprayed from the spray gun.

[0006] The principle of this scheme is as follows: dilution water from the dilution tank enters the mixing pipe, and the denitrification agent solution enters the mixing pipe from the denitrification agent storage tank. The mixed solution is pressurized by a plunger pump to enhance the penetration of the solution and increase the mixing volume with the flue gas. Then, the pressurized mixed solution enters the spray gun and is sprayed into the corresponding equipment for denitrification. At the same time, the air supply device pressurizes the denitrification mixture by jetting it to increase the jet intensity.

[0007] Advantages of this scheme: pressurization is achieved through a plunger pump, which enhances the penetration of the solution; the denitrification mixture is pressurized by a gas supply device to increase the jet intensity of the solution and reduce the evaporation rate of the solution by the high-temperature flue gas, so that the denitrification mixture and the flue gas are fully mixed and denitrified.

[0008] Preferably, it also includes a distribution pipe, the mixing pipe being connected to the plunger pump via the distribution pipe.

[0009] Preferably, it also includes a delivery pump, wherein the dilution water tank is connected to the mixing pipe via the delivery pump, and the denitrification agent storage tank is connected to the mixing pipe via the delivery pump.

[0010] Preferably, the spray gun includes a nozzle and a nozzle head. The two ends of the nozzle are connected to a plunger pump and the nozzle head, respectively. The diameter of the nozzle first decreases and then increases along the direction of the nozzle head. The decrease and increase of the nozzle diameter creates a Venturi effect. When the fluid enters the part of the nozzle where the diameter gradually decreases, the pressure decreases and the fluid velocity increases. That is, the flow velocity of the denitrification solution increases in the narrower part of the nozzle, thereby increasing the flow velocity of the denitrification mixture solution in the nozzle.

[0011] Preferably, the air supply device includes a compressed air duct located outside the nozzle. The compressed air duct is open at one end of the nozzle and closed at the other end. The compressed air duct and the outside of the nozzle form an air cavity, and a cooling air inlet is provided on the side of the compressed air duct. Compressed air enters the air cavity through the cooling air inlet and then flows from the air cavity to the outside of the nozzle, pressurizing the denitrification mixture at the nozzle and increasing the jet intensity.

[0012] Preferably, the side of the compressed air duct is provided with at least one cooling air outlet.

[0013] Preferably, the cooling air outlet is arranged along the tangential direction of the compressed air duct. When the cooling air outlet is arranged tangentially, a spiral airflow is formed at the cooling air outlet of the compressed air duct, which reduces gas backflow, reduces fluid residence time, and improves flow efficiency.

[0014] Preferably, the inner wall of the compressed air duct is provided with a guide groove to guide the airflow and facilitate the concentrating of the denitrification mixed solution.

[0015] Preferably, the nozzle includes a first orifice plate and a second orifice plate. The first orifice plate has a first through hole, and the second orifice plate has a second through hole. The first and second orifice plates are arranged to rotate relative to each other and overlap. When the first and second orifice plates rotate, the size of the holes can be adjusted by partially overlapping. At the same time, pulse jet can be achieved by changing the overlap area of ​​the nozzles in some areas, which is beneficial for flue gas denitrification. Attached Figure Description

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

[0017] Figure 2 This is a partial structural schematic diagram of an embodiment of the present utility model.

[0018] Figure 3 This is a schematic diagram of the nozzle structure in an embodiment of the present invention. Detailed Implementation

[0019] The following detailed description illustrates the specific implementation method:

[0020] The reference numerals in the accompanying drawings include: 1. dilution water tank; 2. denitrification agent storage tank; 3. mixing pipe; 4. distribution pipe; 5. plunger pump; 6. spray gun; 61. spray pipe; 62. nozzle; 7. compressed air pipe; and 71. cooling air outlet.

[0021] Example:

[0022] A high-speed jet spray gun system for flue gas SNCR denitrification, such as Figure 1 , Figure 2 and Figure 3 As shown, it includes: a dilution water tank 1, a denitrification agent storage tank 2, an air supply device, and a mixing pipe 3, a plunger pump 5, and a spray gun 6 connected in sequence.

[0023] Dilution water tank 1 is used to store dilution water, and denitrification agent tank 2 is used to store denitrification agent. The composition of the dilution water and denitrification agent is based on existing technology and will not be described in detail here. The dilution water tank adopts a vertical cylindrical structure and integrates a 316L stainless steel spiral coil heat exchanger. The water temperature is controlled by a PID temperature control module to prevent the denitrification agent, such as urea solution, from crystallizing at low temperatures.

[0024] Both the dilution water tank 1 and the denitrification agent storage tank 2 are connected to the mixing pipe 3. The connection point between the mixing pipe 3 and the dilution water tank 1 is located at the bottom of the dilution water tank 1, and the connection point between the mixing pipe 3 and the denitrification agent storage tank 2 is located at the bottom of the denitrification agent storage tank 2. A transfer pump is also included. The dilution water tank 1 and the denitrification agent storage tank 2 are connected to the mixing pipe 3 via the transfer pump. The transfer pump lifts the dilution water and denitrification agent into the mixing pipe 3. The transfer pump allows for control of the addition rate of the dilution water and denitrification agent, facilitating adjustment of the dilution water and denitrification agent ratio. Flow valves can also be installed on the corresponding pipelines to further control the ratio of dilution water and denitrification agent. Specifically, in this embodiment, the dilution water tank 1 uses a centrifugal pump to deliver water to the mixing pipe 3, and the denitrification agent storage tank 2 uses a centrifugal pump to deliver the denitrification agent to the mixing pipe 3.

[0025] It also includes a distribution pipe 4, and a mixing pipe 3 is connected to a plunger pump 5 via the distribution pipe 4. In this embodiment, multiple cooperating pipes are provided, which can simultaneously control multiple spray guns 6 to work, improving the efficiency of flue gas denitrification. The mixed solution is pressurized by the plunger pump 5 to enhance the penetration of the solution and increase the mixing volume with the flue gas. The plunger pump adopts a three-cylinder hydraulic drive structure. In this scheme, the distribution pipe system adopts a main pipeline branch structure, and the flow of each branch is balanced by a dynamic balancing valve.

[0026] The spray gun 6 includes a nozzle 61 and a nozzle 62. The nozzle 61 is connected to a plunger pump 5 at both ends and the nozzle 62 at the other end. The diameter of the nozzle 61 decreases and then increases along the direction of the nozzle 62. This decrease in nozzle diameter creates a Venturi effect; when fluid enters the gradually decreasing diameter section of the nozzle 61, the pressure decreases, and the fluid velocity increases. Specifically, the denitrification solution velocity increases at the narrower part of the nozzle 61, thus increasing the velocity of the denitrification mixture within the nozzle 61. In this embodiment, the nozzle 61 is made of 316L stainless steel, and its inner diameter changes in three sections along the axial direction: the inlet section has a diameter of 80mm, the contraction section gradually narrows to a minimum diameter of 32mm with a 15° cone angle, and the diffusion section gradually expands to an outlet diameter of 60mm with an 8° cone angle. The inner wall of the nozzle 61 is coated with a laser-laminated tungsten carbide coating to reduce turbulent friction losses.

[0027] The nozzle 62 includes a first orifice plate and a second orifice plate. The first orifice plate has a first through hole, and multiple first through holes are evenly distributed on the first orifice plate. These multiple first through holes effectively disperse the liquid, increasing the contact area with the flue gas and improving the flue gas denitrification effect. The second orifice plate has a second through hole, and multiple second through holes are evenly distributed on the second orifice plate. These multiple second through holes also effectively disperse the liquid, increasing the contact area with the flue gas and improving the flue gas denitrification effect. The first and second orifice plates are arranged in a relatively rotatable, overlapping configuration. When the first and second orifice plates rotate, the size of the holes can be adjusted by partially overlapping them. Simultaneously, the change in the overlap area of ​​the nozzle 62 in some areas enables pulse jetting, which is beneficial for flue gas denitrification. In this embodiment, the first and second orifice plates have the same size and structure. A threaded connection allows the two orifice plates to rotate relative to each other, and the overlap area of ​​the through holes is continuously adjustable between 0% and 100%.

[0028] The air supply device is used to pressurize the denitrification solution sprayed from the spray gun 6. After being pressurized by the plunger pump 5, the mixed solution enters the spray gun 6 and is sprayed into the corresponding equipment for denitrification. At the same time, the air supply device pressurizes the denitrification mixture to increase the jet intensity. Pressurization by the plunger pump 5 enhances the penetration of the solution; pressurization of the denitrification mixture by the air supply device increases the jet intensity of the solution and simultaneously cools the solution, reducing the evaporation rate of the solution by the high-temperature flue gas.

[0029] The air supply device includes a compressed air duct 7, located outside the nozzle 61. The compressed air duct 7 is open at one end of the nozzle 62 and closed at the other. The compressed air duct 7 and the outside of the nozzle 61 form an air cavity. A cooling air inlet 71 is provided on the side of the compressed air duct 7. Compressed air enters the air cavity through the cooling air inlet 71 and then flows from the air cavity to the outside of the nozzle 62, pressurizing the denitrification mixture at the nozzle 62 and increasing the jet intensity. In this embodiment, compressed cold air is introduced into the air cavity, which cools the nozzle 61 and the liquid, reduces the evaporation rate of the solution from the high-temperature flue gas, increases the penetration ability of the solution, and ensures thorough mixing and denitrification of the denitrification mixture with the flue gas. Simultaneously, it cools the corresponding structures, increasing the service life of the spray gun 6.

[0030] At least one cooling air outlet 71 is provided on the side of the compressed air duct 7. The cooling air outlet 71 is arranged along the tangential direction of the compressed air duct 7. The tangential direction of the cooling air outlet 71 forms a spiral airflow at the cooling air outlet 71 of the compressed air duct 7, which reduces gas backflow, reduces fluid residence time, and improves flow efficiency. In this embodiment, there are two symmetrical cooling air outlets 71.

[0031] The inner wall of the compressed air duct 7 is provided with a guide groove, which is axially arranged to guide the airflow and facilitate the concentrating of the denitrification mixed solution. In this embodiment, the air cavity is divided into three sections along the axial direction: the inlet section: two symmetrically distributed upper and lower cooling air inlets 71 are provided; the transition section: the inner wall is machined with axial guide grooves, which are evenly distributed with a groove spacing of 15° to eliminate airflow turbulence; the spray section: the end is trumpet-shaped, and the distance between the outlet end face and the nozzle end face is 5mm, forming an annular air curtain.

[0032] The specific implementation process is as follows:

[0033] Diluent water in dilution tank 1 is pumped into mixing pipe 3 via a transfer pump. Denitrification agent solution is pumped from denitrification agent storage tank 2 into mixing pipe 3 via a transfer pump. The flow rate of the transfer pump can be adjusted according to actual needs to ensure that diluent water and denitrification agent solution enter mixing pipe 3 in a preset ratio. The mixed solution is pressurized by plunger pump 5 to enhance the penetration of the solution and increase the mixing volume with flue gas. Then, the pressurized denitrification mixed solution enters nozzle 61 and is sprayed from nozzle 62 into the corresponding equipment to denitrify the flue gas. Compressed cold air is injected into compressed air pipe 7 through cooling air outlet 71. The cold air contacts the denitrification mixed solution near nozzle 62, cooling and pressurizing the denitrification mixed solution to improve the solution jet intensity. At the same time, the size of the nozzle can be adjusted by adjusting the relative position of the first orifice plate and the second orifice plate, and the nozzle can be controlled to spray the denitrification mixed solution in a pulse manner to ensure the denitrification effect of the flue gas.

[0034] This scheme uses a plunger pump 5 to pressurize the solution, enhancing its penetration; a gas supply device to pressurize the denitrification mixture solution by jetting, increasing the jet intensity of the solution while reducing the evaporation rate of the solution by the high-temperature flue gas; adjusting the relative positions of the first and second orifice plates to adjust the nozzle size and controlling the nozzle to spray the denitrification mixture solution in a pulse manner to ensure the denitrification effect of the flue gas; the diameter of the nozzle 61 first decreases and then increases, forming a Venturi effect, increasing the flow velocity of the denitrification solution at the narrower part of the nozzle 61, thus increasing the flow velocity of the denitrification mixture solution within the nozzle 61.

[0035] 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 system for flue gas SNCR denitrification, characterized in that, include: The system includes a dilution water tank, a denitrification agent storage tank, an air supply device, and a mixing pipe, a plunger pump, and a spray gun connected in sequence. The dilution water tank is connected to the mixing pipe, and the connection between the mixing pipe and the dilution water tank is located at the bottom of the dilution water tank. The denitrification agent storage tank is connected to the mixing pipe, and the connection between the mixing pipe and the denitrification agent storage tank is located at the bottom of the denitrification agent storage tank. The air supply device is used to pressurize the denitrification solution sprayed from the spray gun.

2. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 1, characterized in that: It also includes a distribution pipe, which is connected to the plunger pump via the distribution pipe.

3. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 1, characterized in that: It also includes a delivery pump, the dilution water tank is connected to the mixing pipe via the delivery pump, and the denitrification agent storage tank is connected to the mixing pipe via the delivery pump.

4. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 1, characterized in that: The spray gun includes a nozzle and a nozzle head. The two ends of the nozzle are connected to a plunger pump and the nozzle head, respectively. The diameter of the nozzle first decreases and then increases along the direction of the nozzle head.

5. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 4, characterized in that: The air supply device includes a compressed air pipe located outside the nozzle. The compressed air pipe is open at the nozzle end and closed at the other end. The compressed air pipe and the outside of the nozzle form an air cavity. A cooling air inlet is provided on the side of the compressed air pipe.

6. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 5, characterized in that: At least one cooling air vent is provided on the side of the compressed air duct.

7. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 5, characterized in that: The cooling air vents are arranged along the tangent of the compressed air duct.

8. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 5, characterized in that: The inner wall of the compressed air duct is provided with a guide groove.

9. The high-speed jet spray gun system for flue gas SNCR denitrification according to claim 4, characterized in that: The nozzle includes a first orifice plate and a second orifice plate. The first orifice plate has a first through hole, and the second orifice plate has a second through hole. The first orifice plate and the second orifice plate are arranged to rotate and overlap relative to each other.

Images