Denitration reactor
By integrating heating, dust removal, and denitrification functions into the denitrification reactor, the problems of complex equipment and low denitrification efficiency in existing technologies are solved, achieving efficient flue gas treatment that is suitable for industrial applications.
Patent Information
- Application Number
- CN202423143345.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-11-11
- Estimated Expiration
- 2034-12-19
AI Technical Summary
Existing technologies cannot simultaneously achieve heating, dust removal, and denitrification in a single device, resulting in complex equipment and low denitrification efficiency. In particular, the catalyst is prone to deactivation in flue gas with high dust content.
Design a denitrification reactor comprising an outer shell and an inner liner. Superheated steam is introduced through the annular gap between the outer shell and the inner liner for heating. A secondary mixing zone and a catalytic reaction zone are set in the inner liner. The denitrification reaction is carried out with the catalyst through a fiber reaction tube, realizing the integration of flue gas heating, dust removal and denitrification.
It enables denitrification of flue gas at high temperatures, making full use of heat, with simple equipment, high denitrification efficiency, suitable for industrial applications, and long service life.
Smart Images
Figure CN223530220U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of environmental protection technology, specifically to a denitrification reactor. Background Technology
[0002] With the continuous development of modern society, people's demand for energy is increasing day by day. While consuming energy, many pollutants are also generated, causing varying degrees of harm to ecosystems and organisms. Among them, nitrogen oxides, as one of the major sources of pollution, seriously damage the ecological environment and people's living environment.
[0003] In recent years, researchers have been continuously exploring technologies to reduce nitrogen oxide emissions, including combustion control and flue gas emission control. Among these, controlling the formation of nitrogen oxides at the source is considered the most effective method. Existing technologies for controlling nitrogen oxides in flue gas emissions mainly include adsorption, absorption, oxidation absorption, and catalytic reduction. Catalytic reduction is the most widely used in industry and is considered the most effective method for eliminating nitrogen oxides in industrial applications.
[0004] Catalytic reduction can be divided into selective catalytic reduction (SCR) and selective non-catalytic reduction (SCCR). However, SCCR involves high reaction temperatures, complex processes, and high consumption of reducing agents. While SCCR, with its lower reaction temperatures and simpler operation, is widely used for nitrogen oxide (NOx) removal, it is more suitable for clean flue gas. For flue gas with high dust content, dust can deactivate the catalyst during the denitrification process. Therefore, a flue gas dust removal facility is often required before NOx removal. Furthermore, SCCR has strict temperature requirements; regardless of whether a medium-low or medium-high temperature catalyst is used, the flue gas needs to be preheated to a specified temperature. This necessitates both a pre-heating and pre-dust removal facility, making the equipment complex. Therefore, given the predicament of many industrial plants in China failing to meet NOx and particulate matter standards in their exhaust gases, there is an urgent need for a simpler and more efficient equipment that can simultaneously perform heating, dust removal, and NOx removal. Utility Model Content
[0005] The purpose of this invention is to overcome the problem that existing technologies cannot simultaneously achieve heating, dust removal, and denitrification in a single device. This invention provides a denitrification reactor with an outer shell and an inner liner. Superheated steam is introduced through the gap between the two parts, keeping the reaction zone in the inner liner at a constant high temperature, thus maximizing heat utilization. This single device can complete the three processes of flue gas heating, denitrification, and dust removal, enabling simple and rapid heating, denitrification, and dust removal of flue gas to meet emission requirements. The operation is simpler, the denitrification performance is stable, and it is more suitable for industrial applications.
[0006] To achieve the above objectives, this utility model provides a denitrification reactor, which includes an outer shell and an inner liner. The outer shell is arranged around the outer periphery of the inner liner to form an annular heating zone. The lower end of the inner liner is provided with a flue gas inlet, and the upper end is provided with a flue gas outlet. The inner cavity of the inner liner is provided with one or more layers of fiber reaction tubes. Flue gas enters the tube from the outer wall of the fiber reaction tube and reacts with the catalyst inside the tube to carry out a denitrification reaction. The reacted flue gas is output from the top of the fiber reaction tube.
[0007] Preferably, the inner cavity of the inner liner is configured from bottom to top as a secondary mixing zone and a catalytic reaction zone, and one or more layers of fiber reaction tubes are disposed in the catalytic reaction zone.
[0008] Preferably, the secondary mixing zone is provided with a plurality of baffles.
[0009] Preferably, the number of baffles in the secondary mixing zone is 3-6.
[0010] Preferably, the denitrification reactor further includes a primary mixing zone connected to the flue gas inlet, and the primary mixing zone is provided with a spray device for injecting a reducing agent.
[0011] Preferably, the spraying direction of the spraying device is opposite to the flow direction of the flue gas in the primary mixing zone, so that the reducing agent sprayed through the spraying device mixes with the flue gas in a countercurrent manner.
[0012] Preferably, in each layer of fiber reaction tubes, a plurality of fiber reaction tubes are disposed within the inner liner via a reaction tube distributor.
[0013] Preferably, the upper part of the outer casing is provided with a steam inlet, and the lower part is provided with a steam outlet.
[0014] Preferably, there are 3 to 10 steam inlets, which are arranged around the upper part of the housing.
[0015] Preferably, each of the steam inlets is provided with a steam nozzle, and the spray angle of the steam nozzle is 90-150°.
[0016] Through the above technical solution, by setting an annular heating zone 7 between the outer shell 1 and the inner liner 2, the flue gas can be heated from the moment it enters the reactor and maintained at a high temperature before reacting with the catalyst inside the tube for denitrification. This results in more efficient heat utilization and higher reaction efficiency. In a preferred embodiment, superheated steam is introduced between the outer shell and the inner liner of the denitrification reactor to heat the inner liner. The inner liner is divided into a secondary mixing zone and a catalytic reaction zone. The flue gas is first further mixed and heated to the temperature required for the denitrification reaction in the secondary mixing zone, and then enters the catalytic reaction zone to react. The catalytic reaction zone remains at a high temperature, preventing the formation of ammonium salts that clog the fiber pores of the tube wall during denitrification. This also ensures more efficient heat utilization. A single device can complete the three processes of flue gas heating, denitrification reaction, and dust removal. This allows for simple and rapid heating, denitrification, and dust removal of flue gas to meet emission requirements. The operation is simpler, the denitrification index is stable, and the equipment has a long service life, making it more suitable for industrial applications. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the internal structure of the denitrification reactor described in this utility model;
[0018] Figure 2 This is a top view of the internal structure of the denitrification reactor described in this utility model;
[0019] Figure 3 This is a schematic flowchart of the flue gas denitrification method described in this utility model.
[0020] Explanation of reference numerals in the attached figures
[0021] 1. Outer shell; 2. Inner liner; 3. Baffle plate; 4. Fiber reaction tube; 5. Reaction tube distributor; 6. Steam inlet; 7. Annular gap heating zone; 8. Secondary mixing zone; 9. Nozzle; 10. Flue gas inlet; 11. Flue gas outlet; 12. Steam outlet; 13. Spray device; 14. Reducing agent regulating valve; 15. Steam regulating valve; 16. Catalytic reaction zone; 17. Primary mixing zone. Detailed Implementation
[0022] The specific embodiments of this utility model are described in detail below. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of this utility model.
[0023] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0024] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. The term "comprising" and any variations thereof mean non-exclusive inclusion, where one or more other features, integers, steps, operations, units, components, and / or combinations thereof may be present or added.
[0025] In addition, terms such as “center,” “horizontal,” “up,” “down,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer” that indicate orientation or positional relationship are based on the orientation or relative positional relationship shown in the accompanying drawings. They are only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.
[0026] Furthermore, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0027] like Figure 1 and 2As shown, the denitrification reactor of this invention includes an outer shell 1 and an inner liner 2. The outer shell 1 surrounds the outer periphery of the inner liner 2, forming an annular heating zone 7. The lower end of the inner liner 2 is provided with a flue gas inlet 10, and the upper end is provided with a flue gas outlet 11. The inner cavity of the inner liner 2 is provided with one or more layers of fiber reaction tubes 4. Flue gas enters the tube from the outer wall of the fiber reaction tube 4 and reacts with the catalyst inside the tube to carry out a denitrification reaction. The reacted flue gas is output from the top of the fiber reaction tube 4. By setting an annular heating zone 7 between the outer shell 1 and the inner liner 2, this invention allows the flue gas to be heated from the moment it enters the reactor and to remain at a high temperature before reacting with the catalyst inside the tube to carry out a denitrification reaction. This results in more efficient heat utilization and higher reaction efficiency.
[0028] According to the denitrification reactor of this utility model, the inner cavity of the inner liner 2 is configured from bottom to top as a secondary mixing zone 8 and a catalytic reaction zone 16, and one or more layers of fiber reaction tubes 4 are disposed in the catalytic reaction zone 16. The secondary mixing zone 8 is first set at the bottom of the inner liner 2 of the denitrification reactor, which allows the incoming flue gas to be further mixed evenly and heated to the temperature required for the denitrification reaction before entering the catalytic reaction zone 16 to react. The number of fiber reaction tubes 4 in the catalytic reaction zone 16 can be adjusted according to the nitrogen oxide content in the flue gas to ensure the efficiency of flue gas denitrification.
[0029] According to the denitrification reactor of this utility model, a plurality of baffles 3 are provided in the secondary mixing zone 8. In a preferred embodiment, the number of baffles 3 in the secondary mixing zone 8 is 3-6. By configuring the baffles 3, on the one hand, the turbulent mixing of the flue gas and reducing agent mixture can be enhanced, resulting in a higher efficiency of the denitrification reaction; on the other hand, the flue gas residence time can be extended, allowing the flue gas and reducing agent mixture entering the secondary mixing zone 8 to be further fully mixed. Furthermore, by controlling the injection of superheated steam in the annular heating zone 7, the temperature of the flue gas can be adjusted to the temperature required for the denitrification reaction, and the denitrification reaction will subsequently occur in the catalytic reaction zone.
[0030] According to the denitrification reactor of this utility model, the denitrification reactor further includes a primary mixing zone 17 connected to the flue gas inlet, and a spray device 13 for injecting a reducing agent is provided on the primary mixing zone 17. Preferably, the spray direction of the spray device 13 is opposite to the flue gas flow direction in the primary mixing zone 17, so that the reducing agent injected through the spray device 13 mixes countercurrently with the flue gas. In a specific embodiment, the length of the primary mixing zone 17 is not less than 8m, so that the flue gas and the reducing agent can be mixed more thoroughly through countercurrent mixing, resulting in better subsequent catalytic reaction effects.
[0031] According to the denitrification reactor of this utility model, in each layer of fiber reaction tubes 4, a plurality of fiber reaction tubes are arranged inside the inner liner 2 via reaction tube distributors 5. The reaction tube distributors 5 have openings arranged according to the outer diameter of the fiber reaction tubes 4, and the arrangement can be an equilateral triangle or a grid pattern. In some specific embodiments, each reaction tube distributor has 4-8 fiber reaction tubes 4, the length of which is 1-4 meters, and they are evenly distributed on the reaction tube distributors 5.
[0032] According to the denitrification reactor of this invention, the catalytic reaction zone 16 is provided with 2-3 layers of fiber reaction tubes 4. The number of fiber reaction tubes 4 in the catalytic reaction zone 16 can be adjusted according to the flue gas flow rate and the nitrogen oxide content in the flue gas, thereby ensuring the efficiency of flue gas denitrification.
[0033] According to the denitrification reactor of this utility model, the upper part of the outer shell 1 is provided with a steam inlet 6 and the lower part with a steam outlet 12. In a preferred embodiment, the number of steam inlets 6 is 3-10, and these steam inlets are arranged around the upper part of the outer shell 1. In a further preferred embodiment, each steam inlet 6 is provided with a steam nozzle 9, and the spray angle of the steam nozzle 9 is 90-150°. In a specific embodiment, the height of the steam inlet 6 on the outer shell 1 is set above the reaction tube distributor 5 of the highest layer of the inner liner 2. Superheated steam can be injected into the annular heating zone 7 at 90-150° through the steam nozzle 9. After heat exchange, the steam (i.e., the cooled steam) is discharged from the steam outlet 12 at the lower end. This ensures that all fiber reaction tubes 4 are at high temperature, which can improve the effect of catalytic denitrification reaction and prevent the flue gas from forming ammonium salts that cover and block the fiber pores of the tube wall during the denitrification reaction. This makes the equipment more durable, stable and efficient.
[0034] According to the denitrification reactor of this utility model, the outer shell 1 is made of thermal insulation material. When the entire outer shell of the equipment is insulated with thermal insulation material, the heat utilization rate of the superheated steam can be higher.
[0035] The internal structure of the denitrification reactor described in this utility model is as follows: Figure 1As shown, in some embodiments, the denitrification reactor comprises an outer shell 1 and an inner liner 2. A flue gas outlet 11 is provided at the top of the inner liner 2, and a flue gas inlet 10 is provided at the bottom. The flue gas enters the inner liner 2 from bottom to top, first passing through a secondary mixing zone 8. The secondary mixing zone 8 has 3-6 baffles 3, which prolong the residence time of the flue gas in the secondary mixing zone 8, thereby raising the temperature to the temperature required for the denitrification reaction. Then it flows upward to the catalytic reaction zone 16, where 1-3 layers of fiber reaction tubes 4 are distributed. Each layer of fiber reaction tubes 4 is evenly distributed and fixed in the reaction tube. On the distributor 5, the heated flue gas enters the fiber reaction tube 4 from the outer wall and reacts with the catalyst inside the tube to undergo a denitrification reaction. The reacted flue gas is output from the top of the fiber reaction tube 4 and finally discharged through the flue gas outlet 11 at the top of the inner liner 2. In the outer shell 1, 3-10 steam inlets 6 are arranged around the upper end of the outer shell 1, and the height of the steam inlets 6 is higher than the uppermost reaction tube distributor 5 in the inner liner 2. A steam outlet 12 is provided at the lower end of the outer shell 1. The gap between the outer shell 1 and the inner liner 2 is an annular heating zone 7, and the diameter of the annular heating zone 7 is greater than 250 mm. The internal top view structure of the denitrification reactor of this utility model is as follows. Figure 2 As shown, 3-10 steam inlets 6 are arranged around the outer shell 1 of the denitrification reactor, and each steam inlet 6 is equipped with a steam nozzle 9, and the spray angle of the steam nozzle 9 is 90-150°.
[0036] The denitrification reactor described in this invention can be used to treat flue gas for denitrification. The specific method and process are as follows: Figure 3 As shown: The reducing agent regulating valve 14 is opened, and the reducing agent is counter-currently introduced into the primary mixing zone 17 using the spray device 13, so that the flue gas and reducing agent achieve homogeneous distribution in the primary mixing zone 17. Then, it is introduced through the lower flue gas inlet 10 of the aforementioned denitrification reactor and undergoes a series of processes including heating, denitrification, and dust removal within the denitrification reactor, before being discharged from the upper flue gas outlet 11. The heating process includes: when the initial temperature of the flue gas is below 180°C, the steam regulating valve 15 is opened, and superheated steam at a temperature of 230-400°C is introduced through the steam inlet 6 above the outer shell 1 of the denitrification reactor. After counter-current heat exchange with the flue gas, it is discharged from the steam outlet below the outer shell 1; when the initial temperature of the flue gas is above 180°C, the steam regulating valve 15 is closed, and superheated steam is not introduced into the annular heating zone 7.
[0037] During the denitrification process of flue gas, the concentration of nitrogen oxides in the flue gas can be 80-200 mg / m³. 3 The concentration of particulate matter can be 20-50 mg / m³. 3After the flue gas is denitrified by the denitrification reactor described in this utility model, the denitrification efficiency of the discharged flue gas can reach over 80%, and the concentration of particulate matter in the denitrified flue gas is less than 5 mg / m³. 3 The concentration of nitrogen oxides is less than 15 mg / m³. 3 .
[0038] During the denitrification process of flue gas, the flow rate of the flue gas is 5000-10000 m3 / h. Controlling the flow rate of the flue gas can maximize the efficiency of this method. When the flow rate is too low, it will cause energy loss and low heat utilization efficiency; when the flow rate is too high, it will affect the final denitrification efficiency and the catalytic reaction will be incomplete.
[0039] In the process of denitrification of flue gas, the reducing agent can be a nitrogen-containing reducing agent commonly used in the art, preferably at least one of ammonia, urea, nitrogen and liquid nitrogen.
[0040] In the process of denitrification treatment of flue gas, the molar ratio of nitrogen in the reducing agent to the molar ratio of nitrogen in the flue gas can be (1-2):1, preferably (1.2-1.5):1. A ratio within the preferred range can improve the catalytic reduction reaction of the flue gas and increase the denitrification efficiency.
[0041] During the denitrification process of flue gas, the catalyst in the fiber reaction tube 4 can be a sulfur-resistant denitrification catalyst commonly used in the art, preferably at least one of a medium-low temperature sulfur-resistant denitrification catalyst and a medium-high temperature denitrification catalyst.
[0042] During the denitrification process of flue gas, the temperature of the superheated steam is 230-400℃. Using superheated steam to exchange heat with flue gas in a countercurrent manner is more efficient, environmentally friendly, and safe.
[0043] During the denitrification process of flue gas, the length of the primary mixing zone 17 can be 8-10m.
[0044] In a specific embodiment, the method for flue gas denitrification using the denitrification reactor described in this utility model is as follows: The reducing agent regulating valve 14 is opened, and the reducing agent is counter-currently introduced into the primary mixing zone 17 using the spray device 13. This allows the flue gas and reducing agent to initially mix and achieve homogeneous distribution in the primary mixing zone 17. Then, the flue gas is introduced from the lower flue gas inlet 10 of the inner liner 2 of the denitrification reactor. The flue gas first passes through the secondary mixing zone 8, where 3-6 baffles 3 are distributed. The baffles 3 allow the flue gas to mix again in the secondary mixing zone 8, and extend the residence time, thereby raising the temperature of the flue gas to the temperature required for the catalytic reaction. The flue gas then moves upwards to the catalytic reaction zone 16, where 1-3 layers of fiber reaction tubes 4 are distributed. Each layer has 4-8 fiber reaction tubes 4 evenly distributed and fixed on the reaction tube distributor 5. The heated flue gas enters the tube from the outer wall of the fiber reaction tube 4 and reacts with the sulfur-resistant denitrification catalyst inside the tube. The reacted flue gas is output from the top of the fiber reaction tube 4 and finally discharged through the flue gas outlet 11 at the top of the inner liner 2. At the same time, when the initial temperature of the flue gas is below 180°C, the steam regulating valve 15 is opened, and superheated steam at a temperature of 230-400°C is introduced from the steam inlet 6 above the outer shell 1 of the denitrification reactor into the annular gap heating zone 7. After countercurrent heat exchange with the flue gas, it is discharged from the steam outlet below the outer shell 1. When the initial temperature of the flue gas is above 180°C, the steam regulating valve 15 is closed.
[0045] The denitrification reactor of this utility model is further illustrated below through embodiments. These embodiments are implemented based on the technical solution of this utility model, providing detailed implementation methods and specific operating procedures. However, the scope of protection of this utility model is not limited to the following embodiments.
[0046] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.
[0047] In the following embodiments, the denitrification reactor is configured as follows: The denitrification reactor comprises an outer shell 1 and an inner liner 2. A flue gas outlet 11 is provided at the top of the inner liner 2, and a flue gas inlet 10 is provided at the bottom. Below the inner liner 2 is a secondary mixing zone 8, in which 3-6 baffles 3 are distributed. Above the secondary mixing zone 8 is a catalytic reaction zone 16, in which 1-3 layers of fiber reaction tubes 4 are distributed. Each layer has 4-8 fiber reaction tubes 4 evenly distributed and fixed on a reaction tube distributor 5. In the outer shell 1, 3-10 steam inlets 6 are arranged around the upper end of the outer shell 1, and the height of the steam inlets 6 is higher than the uppermost reaction tube distributor 5 in the inner liner 2. A steam outlet 12 is provided at the lower end of the outer shell 1, and the gap between the outer shell 1 and the inner liner 2 is an annular heating zone 7.
[0048] Example 1
[0049] The flue gas flow rate used in this embodiment is 7000 m³ / h. 3 / h, temperature 40℃, nitrogen oxide concentration in flue gas 90mg / m³ 3 The particulate matter concentration was 30 mg / m³. 3 .
[0050] Open the reducing agent regulating valve 14, and use the spray device 13 to reverse-flow ammonia gas with a concentration of 0.0252 mol / h into the primary mixing zone 17 with a length of 8 m. This allows the flue gas and ammonia gas to be initially mixed in the primary mixing zone 17 to achieve a homogeneous distribution. Then, the flue gas is introduced from the flue gas inlet 10 below the inner liner 2 of the denitrification reactor. The flue gas first passes through the secondary mixing zone 8, which has three baffles 3. The baffles 3 cause the flue gas to be mixed again in the secondary mixing zone 8, and the residence time is extended, thereby raising the temperature of the flue gas to 180°C. Then, it flows upward to the catalytic reaction zone 16. A layer of six 4-meter-long fiber reaction tubes 4 are distributed. The heated flue gas enters the tube from the outer wall of the fiber reaction tube 4 and reacts with the sulfur-resistant denitrification catalyst inside the tube. The reacted flue gas exits from the top of the fiber reaction tube 4 and is finally discharged through the flue gas outlet 11 at the top of the inner liner 2. Simultaneously, the steam regulating valve 15 is opened, and superheated steam at 350°C is introduced into the annular gap heating zone 7 at an angle of 110° through the six steam inlets 6 above the outer shell 1 of the denitrification reactor. After countercurrent heat exchange with the flue gas, the steam temperature drops to 250°C and is discharged from the steam outlet below the outer shell 1. The flue gas temperature exiting the denitrification reactor after the reaction is 220°C, and the nitrogen oxide concentration is <15mg / m³. 3 Particulate matter concentration <5mg / m³ 3 The denitrification efficiency is shown in Table 1.
[0051] Example 2
[0052] The flue gas flow rate used in this embodiment is 10000 m³ / h. 3 / h, temperature is 120℃, nitrogen oxide concentration in flue gas is 200mg / m³ 3 The particulate matter concentration was 30 mg / m³. 3 .
[0053] Open the reducing agent regulating valve 14, and use the spray device 13 to reverse-flow ammonia gas with a concentration of 0.08 mol / h into the primary mixing zone 17 with a length of 9 m. This allows the flue gas and ammonia gas to be initially mixed in the primary mixing zone 17 to achieve a homogeneous distribution. Then, the flue gas is introduced from the flue gas inlet 10 below the inner liner 2 of the denitrification reactor. The flue gas first passes through the secondary mixing zone 8, which has 5 baffles 3. The baffles 3 cause the flue gas to be mixed again in the secondary mixing zone 8, and the residence time is extended, thereby raising the temperature of the flue gas to 180°C. Then, it flows upward to the catalytic reaction zone 16, which has two... Each layer consists of eight 2.5-meter-long fiber reaction tubes 4. The heated flue gas enters the tubes from the outer wall and reacts with the sulfur-resistant denitrification catalyst inside. The reacted flue gas exits from the top of the fiber reaction tubes 4 and is finally discharged through the flue gas outlet 11 at the top of the inner liner 2. Simultaneously, the steam regulating valve 15 is opened, and superheated steam at 300°C is introduced into the annular heating zone 7 at a 120° angle through eight steam inlets 6 above the outer shell 1 of the denitrification reactor. After counter-current heat exchange with the flue gas, the steam temperature drops to 240°C and is discharged from the steam outlet below the outer shell 1. The flue gas temperature exiting the denitrification reactor after the reaction is 220°C, and the nitrogen oxide concentration is <20 mg / m³. 3 Particulate matter concentration <5mg / m³ 3 The denitrification efficiency is shown in Table 1.
[0054] Example 3
[0055] The flue gas flow rate used in this embodiment is 5000 m³ / h. 3 / h, temperature is 200℃, nitrogen oxide concentration in flue gas is 80mg / m³ 3 The particulate matter concentration was 50 mg / m³. 3 .
[0056] Open the reducing agent regulating valve 14, and use the spray device 13 to backflow urea at a concentration of 0.01 mol / h into the 10 m long primary mixing zone 17. This allows the flue gas and ammonia to initially mix and achieve a homogeneous distribution in the primary mixing zone 17. Then, the flue gas is introduced from the flue gas inlet 10 at the bottom of the inner liner 2 of the denitrification reactor. The flue gas first passes through the secondary mixing zone 8, which has 6 baffles 3. The baffles 3 allow the flue gas and reducing agent to mix again. The flue gas then flows upward to the catalytic reaction zone 16, which has three layers of 4 fiber reaction tubes 4, each 2 m long. The flue gas enters the tube from the outer wall of the fiber reaction tube 4 and reacts with the sulfur-resistant denitrification catalyst inside the tube. The reacted flue gas exits from the top of the fiber reaction tube 4 and is finally discharged through the flue gas outlet 11 at the top of the inner liner 2. The temperature of the flue gas exiting the denitrification reactor after the reaction is 190℃, and the nitrogen oxide concentration is <15 mg / m³. 3 Particulate matter concentration <10mg / m³3 The denitrification efficiency is shown in Table 1.
[0057] Comparative Example 1
[0058] The flue gas denitrification reaction was carried out according to the method of Example 1, except that the denitrification reactor used did not have the annular heating zone 7, the secondary mixing zone 8, and the baffle 3, and superheated steam was not introduced. The temperature of the flue gas exiting the denitrification reactor after the reaction was 35°C, and the nitrogen oxide concentration was 85 mg / m³. 3 Particulate matter concentration 20 mg / m³ 3 The denitrification efficiency is shown in Table 1.
[0059] Table 1
[0060]
[0061] As can be seen from the results in Table 1, the denitrification efficiency of the denitrification reactor described in this invention is significantly higher. Specifically, when using the denitrification reactor described in this invention for flue gas denitrification, the denitrification efficiency and dust removal efficiency can simultaneously reach over 80%. According to the denitrification reactor described in this invention, superheated steam is introduced between the outer shell and the inner liner of the reactor to heat the inner liner. The inner liner is further divided into a secondary mixing zone and a catalytic reaction zone. This allows the introduced flue gas to first be heated to the required temperature for the catalytic reaction in the secondary mixing zone before entering the catalytic reaction zone to react. The catalytic reaction zone remains at a high temperature, ensuring more efficient heat utilization and preventing the formation of ammonium salts that clog the fiber pores of the pipe wall during the denitrification process. Only one device can complete the three processes of flue gas heating, denitrification reaction, and dust removal, making it simpler, faster, and providing stable denitrification indicators, making it more suitable for industrial applications.
[0062] The preferred embodiments of this utility model have been described in detail above; however, this utility model is not limited thereto. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed by this utility model and are all within the protection scope of this utility model.
Claims
1. A denitrification reactor, characterized in that, The denitrification reactor includes an outer shell (1) and an inner liner (2). The outer shell (1) is arranged around the outer periphery of the inner liner (2) and forms an annular heating zone (7). The lower end of the inner liner (2) is provided with a flue gas inlet (10) and the upper end is provided with a flue gas outlet (11). The inner cavity of the inner liner (2) is provided with one or more layers of fiber reaction tubes (4). Flue gas enters the tube from the outer wall of the fiber reaction tube (4) and reacts with the catalyst inside the tube to carry out a denitrification reaction. The flue gas after the reaction is output from the top of the fiber reaction tube (4).
2. The denitrification reactor according to claim 1, characterized in that, The inner cavity of the inner liner (2) is configured from bottom to top as a secondary mixing zone (8) and a catalytic reaction zone (16), and one or more fiber reaction tubes (4) are arranged in the catalytic reaction zone (16).
3. The denitrification reactor according to claim 2, characterized in that, The secondary mixing zone (8) is provided with several baffles (3).
4. The denitrification reactor according to claim 3, characterized in that, In the secondary mixing zone (8), the number of baffles (3) is 3-6.
5. The denitrification reactor according to any one of claims 1-4, characterized in that, The denitrification reactor also includes a primary mixing zone (17) connected to the flue gas inlet, and the primary mixing zone (17) is provided with a spray device (13) for spraying in a reducing agent.
6. The denitrification reactor according to claim 5, characterized in that, The spraying direction of the spray device (13) is opposite to the flow direction of the flue gas in the primary mixing zone (17), so that the reducing agent sprayed through the spray device (13) mixes with the flue gas in a countercurrent manner.
7. The denitrification reactor according to any one of claims 1-4, characterized in that, In each layer of fiber reaction tubes (4), several fiber reaction tubes are arranged in the inner liner (2) through a reaction tube distributor (5).
8. The denitrification reactor according to any one of claims 1-4, characterized in that, The upper part of the outer shell (1) is provided with a steam inlet (6), and the lower part is provided with a steam outlet (12).
9. The denitrification reactor according to claim 8, characterized in that, The number of steam inlets (6) is 3-10, and these steam inlets are arranged around the upper part of the outer shell (1).
10. The denitrification reactor according to claim 8, characterized in that, Each of the steam inlets (6) is provided with a steam nozzle (9), and the spray angle of the steam nozzle (9) is 90-150°.