Spray pipe and flue gas low-nitrogen denitration device

Abstract

The invention relates to the technical field of flue gas treatment, in particular to a spray pipe and a flue gas low-nitrogen denitration device.The spray pipe comprises a spray pipe component, the spray pipe component comprises a pipe body, a nozzle is arranged at the front end of the pipe body, and a coil pipe assembly is arranged in the pipe body; through the arrangement of the spray pipe component and the mixing mechanism, waste gas and reducing gas are fully mixed, the reduction efficiency in the SCR reactor is improved, and the ammonia escape phenomenon is reduced. And through the cooperative arrangement of the pipe body and the spiral pipe, the atomization effect of liquefied gas (ammonia gas) is improved, and the micronization degree of bubbles is high.

Description

Technical Field

[0001] The present invention relates to the technical field of flue gas treatment, and particularly to a nozzle and a low-nitrogen denitration device for flue gas. Background Art

[0002] Environmental pollution refers to the decline in environmental quality caused by human activities or natural factors, including various forms such as air pollution, water pollution, soil pollution, noise pollution, light pollution, and solid waste pollution.

[0003] Air pollution refers to the harm caused to the ecosystem and human health due to the excessive concentration of harmful gases (such as SO2, NOx, CO) or particulate matter (PM2.5, PM10) in the air, and it is an important part of environmental pollution.

[0004] Currently, the denitration technology for NOx mostly adopts the selective catalytic reduction method (SCR technology). Its principle is that in the presence of a catalyst, by injecting a denitration reagent such as ammonia or urea into the reactor, nitrogen monoxide is reduced to nitrogen, and the denitration efficiency can reach more than 90%.

[0005] SCR technology is widely used in thermal power plants and has achieved remarkable results in practice. Among them, compared with the traditional high-temperature SCR technology, the low-temperature SCR technology (usually below 180°C) can effectively reduce the emission of NOx and has the advantages of low energy consumption and less investment.

[0006] During the operation of the SCR system, ammonia slip may occur, that is, the unreacted ammonia is carried out of the furnace outlet with the flue gas or fly ash and leaks into the environment, forming secondary pollution. The possible reasons for ammonia slip include factors such as excessive ammonia injection, degradation of catalyst performance, uneven flue gas flow field, poor atomization effect, and improper temperature control. Summary of the Invention

[0007] In view of the problem of poor ammonia atomization effect in the above or existing technologies, the present invention is proposed.

[0008] Therefore, the object of the present invention is to provide a nozzle.

[0009] To solve the above technical problems, the present invention provides the following technical solution: a nozzle component, the nozzle component includes a pipe body, a nozzle is provided at the front end of the pipe body, and a spiral pipe assembly is provided inside the pipe body.

[0010] As a preferred solution of the nozzle of the present invention, wherein: the spiral pipe assembly includes a spiral pipe, and the spiral pipe extends in a spiral shape.

[0011] As a preferred solution of the nozzle of the present invention, wherein: a plurality of the spiral pipes are provided, and the plurality of spiral pipes are twisted with each other.

[0012] As a preferred embodiment of the nozzle of the present invention, the nozzle is conically arranged.

[0013] Advantages of the nozzle of the present invention: Through the cooperation of the pipe body and the spiral pipe, the atomization effect of liquefied gas (ammonia) is improved, and the degree of bubble refinement is high.

[0014] In view of the actual use process, there is still a problem of uneven flue gas flow field.

[0015] To solve the above technical problems, the present invention also provides the following technical solution: A flue gas low-nitrogen denitration device, including a nozzle, and

[0016] A mixing mechanism, the mixing mechanism includes a main body housing, and the main body housing includes an air inlet chamber, a mixing chamber and a buffer chamber which are connected in sequence.

[0017] As a preferred embodiment of the flue gas low-nitrogen denitration device of the present invention, the nozzle components are inserted at equal intervals on the circumferential side wall of the air inlet chamber, and the number of the nozzle components is an even number.

[0018] As a preferred embodiment of the flue gas low-nitrogen denitration device of the present invention, the inner diameter of the mixing chamber is smaller than the inner diameters of the air inlet chamber and the buffer chamber.

[0019] As a preferred embodiment of the flue gas low-nitrogen denitration device of the present invention, the mixing mechanism further includes a mixing component, and the mixing component includes a bracket, and the bracket is arranged on the inner wall of the mixing chamber.

[0020] As a preferred embodiment of the flue gas low-nitrogen denitration device of the present invention, the mixing component further includes a fan, and the fan is rotatably connected to the bracket.

[0021] As a preferred embodiment of the flue gas low-nitrogen denitration device of the present invention, the mixing mechanism further includes an air inlet component, and the air inlet component includes an air inlet pipe, and the air inlet pipe is inserted at the air inlet end of the air inlet chamber, and a flange is arranged on the air inlet pipe, and the flange is adapted to the air inlet end of the air inlet chamber.

[0022] Advantages of the flue gas low-nitrogen denitration device of the present invention: Through the arrangement of the nozzle components and the mixing mechanism, the waste gas and the reducing gas are fully mixed, the reduction efficiency in the SCR reactor is improved, and the phenomenon of ammonia slip is reduced. Description of the Drawings

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other accompanying drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is an overall schematic diagram of the nozzle.

[0025] Figure 2 It is a structural schematic diagram of the swirl tube assembly.

[0026] Figure 3 It is a cross-sectional view of the pipe body.

[0027] Figure 4 It is a structural schematic diagram of the flue gas low-nitrogen denitration device.

[0028] Figure 5 It is a cross-sectional view of the flue gas low-nitrogen denitration device.

[0029] Figure 6 It is a structural schematic diagram of the hybrid component. Detailed implementation manners

[0030] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below in conjunction with the detailed implementation manners and the accompanying drawings.

[0031] The terms used in the present invention are those general terms that are currently widely used in the art in consideration of the functions of the present invention. However, these terms can change according to the intentions of those of ordinary skill in the art, precedents, or new technologies in the art. In addition, specific terms can be selected by the applicant, and in this case, their detailed meanings will be described in the detailed description of the present invention. Therefore, the terms used in the specification should not be understood as simple names, but based on the meanings of the terms and the overall description of the present invention.

[0032] The present invention provides a nozzle, and the nozzle is used to atomize the conveyed liquid.

[0033] Specifically, it includes a nozzle component 1. Refer to Figure 3 , the nozzle component 1 includes a pipe body 11, and a nozzle 12 is provided at the front end of the pipe body 11. In this embodiment, the pipe body 11 is arranged in a circular pipe, and high-pressure air is conveyed inside it.

[0034] As an alternative embodiment, refer to Figure 1 and 2 , a swirl tube assembly 13 is arranged inside the pipe body 11.

[0035] Furthermore, refer to Figure 2, the swirl tube assembly 13 includes a spiral tube 131 which extends in a spiral shape. The spiral tube 131 is used to transport liquefied gas. When the liquefied gas passes through the spiral tube 131, it obtains rotational momentum and forms a rotating liquid flow. The outlet of the spiral tube 131 is arranged at the connection between the tube body 11 and the nozzle 12.

[0036] In this embodiment, the liquefied gas is liquefied ammonia.

[0037] As an alternative embodiment, referring to Figure 2 , a plurality of spiral tubes 131 are provided. The plurality of spiral tubes 131 are twisted with each other. In this embodiment, the number of spiral tubes 131 is preferably set to three. The three spiral tubes 131 are twisted into one strand. After the liquefied gas passes through the spiral tubes 131, a rotating liquid flow is formed at the outlet of the spiral tubes 131, which is beneficial to further atomize the liquefied gas.

[0038] As an alternative embodiment, referring to Figure 3 , the nozzle 12 is arranged in a conical shape and is arranged at the fog outlet end of the tube body 11. The high-pressure gas transported in the tube body impacts with the rotating liquid flow at the nozzle 12 to atomize the rotating liquid flow. A spray opening is provided at the smallest end of the nozzle 12, and the liquefied gas is sprayed out at the spray opening of the nozzle 12 after being atomized.

[0039] The present invention also provides a flue gas low-nitrogen denitration device. Referring to Figure 4 and Figure 5 , it includes the aforementioned spray tube, and a mixing mechanism 2. The mixing mechanism 2 includes a main body housing 21. The main body housing 21 includes an air inlet chamber 211, a mixing chamber 212 and a buffer chamber 213 which are connected in sequence.

[0040] As an alternative embodiment, referring to Figure 4 , spray tube components 1 are inserted at equal intervals on the circumferential side wall of the air inlet chamber 211. The number of spray tube components 1 is set to be even. The nozzles 12 of the spray tube components 1 are inserted into the air inlet chamber 211. In this embodiment, the number of spray tube components 1 is preferably six groups, which are arranged in pairs. And the spiral tubes 131 in the two opposite groups of spray tube components 1 rotate in opposite directions, so that greater disturbance occurs between the atomized liquefied gas with a rotating tendency sprayed out from the two opposite spray tube components 1, making the atomized liquefied gas and the flue gas mix more fully and evenly, so that the atomized liquefied gas and the flue gas can fully undergo a chemical reaction to reduce NOx in the flue gas.

[0041] As an alternative embodiment, referring to Figure 5 , the inner diameter of the mixing chamber 212 is smaller than the inner diameters of the air inlet chamber 211 and the buffer chamber 213. When the flue gas and the atomized liquefied gas in the air inlet chamber 211 reach the mixing chamber 212, they are concentrated in the mixing chamber 212, so that the atomized liquefied gas and the flue gas are further mixed.

[0042] As an alternative embodiment, referring to Figure 5 , the mixing mechanism 2 further includes a hybrid component 22, and the hybrid component 22 is used to disturb the atomized liquefied gas and flue gas, so that the atomized gas and the flue gas are mixed more evenly.

[0043] As an alternative embodiment, referring to Figure 6 , the hybrid component 22 includes a bracket 222, and the bracket 222 is arranged on the inner wall of the mixing chamber 212; in this embodiment, the bracket 222 is arranged as two opposite support plates, the top of the support plate is welded to the inner wall of the mixing chamber 212, and a mating hole is provided at the lower part of the support plate for installing the rotating shaft of the fan 221.

[0044] The hybrid component 22 further includes a fan 221, and both ends of the rotating shaft of the fan 221 are fixedly connected to the bracket 222, and the rotating fan stirs the atomized liquefied gas and flue gas passing through the mixing chamber 212.

[0045] As an alternative embodiment, referring to Figure 4 , the mixing mechanism 2 further includes an air intake component 23, and the air intake component 23 includes an air intake pipe 231, the air intake pipe 231 is inserted into the air intake end of the air intake chamber 211, and one end of the air intake pipe 231 located outside the air intake chamber 211 is communicated with a flue gas discharge device.

[0046] A flange 232 is provided on the air intake pipe 231, and the flange 232 is bolted to the air intake end of the air intake chamber 211.

[0047] The air intake component 23 is provided in multiple groups to increase the intake volume of the flue gas and prevent the flue gas from entering the air intake chamber 211 concentratedly, which affects the mixing of the flue gas and the atomized gas and results in unfavorable denitrification of the flue gas.

[0048] The following introduces the basic structure and working principle of the present invention, which will be described with reference to the embodiments shown in the drawings:

[0049] The nozzle component 1 is provided with two layers inside and outside. The inner layer is a spiral tube assembly 13 composed of three spiral tubes. The three spiral tubes are precisely arranged together to form a triple spiral structure. Its main function is to transport liquefied gas.

[0050] When the liquefied gas passes through the spiral tube, the liquefied gas obtains rotational potential energy in the spiral tube and will generate a rotational motion. The rotating liquefied gas is beneficial to enhancing the discrete effect of the liquid during the atomization process.

[0051] The outer layer is a tubular body 11 in the shape of a circular pipe, which is sleeved on the coiled pipe assembly 13. The tubular body 11 is responsible for transporting high-pressure air. The high-pressure air flows rapidly inside the tubular body 11. As the cross-sectional area of the nozzle 12 gradually decreases, the flow rate of the high-pressure air continuously increases, and finally a high-speed air flow is formed at the outlet of the nozzle 12.

[0052] When the liquefied gas and the high-pressure air are simultaneously transported to the nozzle 12, the liquefied gas obtains rotational momentum through the inner coiled pipe, forming a rotating liquid flow. The high-pressure air inside the outer tubular body 11 rapidly expands at the outlet of the nozzle 12, forming a high-speed air flow. The high-speed air flow impacts the rotating liquid, causing the liquefied gas to be atomized.

[0053] Formation of the atomization effect: Due to the strong impact of the high-pressure air and the rotational movement of the liquefied gas, the liquefied gas is rapidly torn into countless tiny droplets, generating an atomization effect. Moreover, the atomized droplets are of uniform size and widely distributed, which can greatly improve the efficiency and uniformity of spraying.

[0054] In addition, the nozzle components 1 are set to six groups, and are inserted into the circumferential side wall of the intake chamber 211 every 60°. This setting method of the nozzle components 1 can fully atomize the liquefied gas and evenly disperse it into the device, enabling the atomized liquefied gas to be evenly mixed with the flue gas, and preventing the liquefied gas from escaping from the reactor without participating in the reaction.

[0055] The flue gas and the atomized liquefied gas initially mixed in the intake chamber 211 are pushed by the intake pressure of the flue gas to the mixing chamber 212 in the middle area of the main body housing 21. The mixing chamber 212 is a region for deep gas mixing.

[0056] A fan 221 is installed in the mixing chamber 212. The inner diameter of the mixing chamber 212 is smaller than the inner diameters of the intake chamber 211 and the buffer chamber 213. When the mixed gas flows through the mixing chamber 212, due to the reduction of the inner diameter of the mixing chamber 212, the flow rate of the mixed gas will rapidly increase, causing the mixed gas to form a more disordered turbulent flow. And the fan in the mixing chamber 212 also helps the flue gas and the atomized liquefied gas to be fully mixed. After the mixed gas enters the buffer chamber 213, the flow rate decreases and gradually stabilizes, and then enters the SCR reaction system through the buffer chamber 213.

[0057] The present invention realizes the full mixing of the waste gas and the reducing gas through the setting of the nozzle components and the mixing mechanism, improves the reduction efficiency in the SCR reactor, and reduces the phenomenon of ammonia escape. Through the coordinated setting of the tubular body and the coiled pipe, the atomization effect of the liquefied gas (ammonia) is enhanced, and the degree of bubble refinement is high.

[0058] Finally, it should be pointed out that the methods and devices described in detail above are only examples, and those skilled in the art can modify these examples in different ways as long as they do not depart from the scope of the present invention.

Claims

1. A nozzle, characterized in that: Comprising, a nozzle component (1), the nozzle component (1) includes a pipe body (11), a nozzle (12) is provided at the front end of the pipe body (11), and a spiral pipe assembly (13) is provided inside the pipe body (11).

2. The nozzle according to claim 1, wherein: the spiral pipe assembly (13) includes a spiral pipe (131), and the spiral pipe (131) is arranged to extend in a spiral shape.

3. The nozzle according to claim 2, wherein: a plurality of the spiral pipes (131) are provided, and the plurality of spiral pipes (131) are screwed together with each other.

4. The nozzle according to any one of claims 1 to 3, wherein: the nozzle (12) is arranged in a conical shape, and a spray opening is provided at the smallest end of the nozzle (12).

5. A flue gas low-nitrogen denitration device, characterized in that: Comprising the nozzle according to any one of claims 1 to 4, and, a mixing mechanism (2), the mixing mechanism (2) includes a main body housing (21), and the main body housing (21) includes an air inlet chamber (211), a mixing chamber (212) and a buffer chamber (213) which are communicated in sequence.

6. The flue gas low-nitrogen denitration device according to claim 5, wherein: the nozzle components (1) are inserted equidistantly on the circumferential side wall of the air inlet chamber (211), and the number of the nozzle components (1) is an even number.

7. The flue gas low-nitrogen denitration device according to claim 6, wherein: the inner diameter of the mixing chamber (212) is smaller than the inner diameters of the air inlet chamber (211) and the buffer chamber (213).

8. The flue gas low-nitrogen denitration device according to claim 7, wherein: the mixing mechanism (2) further includes a mixing component (22), the mixing component (22) includes a bracket (222), and the bracket (222) is arranged on the inner wall of the mixing chamber (212).

9. The flue gas low-nitrogen denitration device according to claim 8, wherein: the mixing component (22) further includes a fan (221), and the fan (221) is rotatably connected to the bracket (222).

10. The flue gas low-nitrogen denitration device according to claim 8 or 9, wherein: the mixing mechanism (2) further includes an air inlet component (23), the air inlet component (23) includes an air inlet pipe (231), the air inlet pipe (231) is inserted into the air inlet end of the air inlet chamber (211), a flange (232) is provided on the air inlet pipe (231), and the flange (232) is adapted to the air inlet end of the air inlet chamber (211).

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