Embedded denitration reactor for zoning drainage of pellet flue gas

Abstract

The invention belongs to the technical field of industrial flue gas denitration, and particularly relates to an embedded denitration reactor for zoned drainage of pellet flue gas, which comprises a rotary kiln and a chain grate machine, the chain grate machine is sequentially provided with a forced air drying section, an air draft drying section, a preheating section I and a preheating section II along a material conveying direction, and the embedded denitration reactor further comprises an SCR denitration reactor, the SCR denitration reactor comprises an SCR-A catalytic zone and an SCR-B catalytic zone, the SCR-A catalytic zone and the SCR-B catalytic zone are arranged in a heat exchange mode, and the gas inlet end of the SCR-A catalytic zone is communicated with the gas outlet end of the preheating section II; the side, close to the preheating section II, of the preheating section I is a denitration adsorption section, the gas outlet end of the denitration adsorption section is communicated with the gas inlet end of the SCR-B catalytic area, the side, away from the preheating section II, of the preheating section I is a direct discharge section, and the gas outlet end of the direct discharge section is communicated with the gas outlet end of the induced draft drying section and the gas inlet end of the chimney; and the air outlet ends of the SCR-A catalytic area and the SCR-B catalytic area are converged and then are communicated with the air inlet end of the air draft drying section.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial flue gas denitration, and in particular relates to an embedded denitration reactor for zoned drainage of pelletized flue gas. Background Art

[0002] The chain grate-rotary kiln process is one of the core equipment for pellet production and is particularly suitable for energy structures using pulverized coal as fuel. In this process, NOx is mainly generated in the high-temperature calcination area from the chain grate preheating section to the rotary kiln, with emission concentrations reaching 500-800 mg / m 3 , and mainly thermal NOx.

[0003] However, traditional end-of-pipe denitrification technology, due to high energy consumption and difficulty controlling ammonia escape rates, can no longer meet the demands of green production. Consequently, embedded SCR denitrification technology, which directly utilizes process waste heat and requires no external energy, has become a key development direction in the industry.

[0004] In current engineering practice, an embedded SCR reactor is typically placed between the preheating II section and the drying section of the grate, leveraging the flue gas temperature of 350-450°C in this range to achieve efficient denitrification. However, during grate operation, negative pressure fluctuations between the preheating I and II sections often cause cross-flow, resulting in the actual gas volume entering the reactor exceeding the designed value. This further causes problems such as flow disturbances within the reactor and imbalance in the total amount of gas at the outlet, which in turn affects the quality of the pellets.

[0005] Therefore, an embedded denitrification reactor with partitioned drainage of pelletized flue gas is urgently needed to solve the problem. Summary of the Invention

[0006] The purpose of the present invention is to provide an embedded denitrification reactor with partitioned drainage of pellet flue gas to solve the above problems.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] An embedded denitrification reactor for zoned drainage of pelletizing flue gas comprises a rotary kiln and a chain grate, wherein the feed end of the rotary kiln is connected to the discharge end of the chain grate, and the chain grate is sequentially provided with a blast drying section, an exhaust drying section, a preheating section I, and a preheating section II along the material conveying direction, and further comprises:

[0009] An SCR denitration reactor, comprising an SCR-A catalytic zone and an SCR-B catalytic zone, wherein the SCR-A catalytic zone and the SCR-B catalytic zone are heat exchanged with each other, and the air inlet end of the SCR-A catalytic zone is connected to the air outlet end of the preheating section II;

[0010] The side of the preheating section I close to the preheating section II is a denitration adsorption section, the outlet end of the denitration adsorption section is connected to the inlet end of the SCR-B catalytic zone, and the side of the preheating section I away from the preheating section II is a straight-discharge section, the outlet end of the straight-discharge section is connected to the outlet end of the exhaust drying section and the inlet end of the chimney;

[0011] The gas outlet ends of the SCR-A catalytic zone and the SCR-B catalytic zone are connected to the gas inlet end of the exhaust drying section after merging.

[0012] Optionally, a plurality of bellows are provided at the bottom of the chain grate, and the air outlet ends of the plurality of bellows located in the preheating section II are connected to the air inlet end of a high-temperature flue through independent branch pipes, and the air outlet end of the high-temperature flue is connected to the SCR-A catalytic zone.

[0013] Optionally, the plurality of wind boxes located in the denitrification adsorption section are connected to the air inlet end of the low-temperature flue through another independent branch pipe, and the air outlet end of the low-temperature flue is connected to the air inlet end of the SCR-B catalytic zone.

[0014] Optionally, the SCR-A catalytic zone is a cylindrical structure, and a catalyst 1 is provided in the SCR-A catalytic zone;

[0015] The SCR-B catalytic zone includes a heat exchange sleeve and a denitrification tube. The heat exchange sleeve is sleeved on the outside of the SCR-A catalytic zone. The heat exchange sleeve is arranged for heat exchange with the SCR-A catalytic zone. The air inlet end of the heat exchange sleeve is connected to the air outlet end of the low-temperature flue, and the air outlet end of the heat exchange sleeve is connected to the air inlet end of the denitrification tube. Catalyst 2 is provided in the denitrification tube.

[0016] The outlet end of the purified gas outlet 2 of the denitrification cylinder and the purified gas outlet 1 of the SCR-A catalytic zone are simultaneously connected to the air inlet end of the confluence pipe, and the outlet end of the confluence pipe is connected to the exhaust drying section through the composite air inlet.

[0017] Optionally, a cross guide plate is provided in the confluence pipe, and the cross guide plate is used to evenly mix the two gases discharged from the purified gas outlet 2 and the purified gas outlet 1.

[0018] Optionally, a functional partition is provided between the heat exchange sleeve and the denitrification cylinder, and gradient micropores are provided on the functional partition.

[0019] Optionally, the large diameter end of the gradient micropore is arranged close to the functional separator SCR-B side, and the small diameter end of the gradient micropore is arranged close to the functional separator SCR-A side.

[0020] Optionally, the large diameter end of the gradient micropore is 2 mm, the small diameter end of the gradient micropore is 0.5 mm, and the gradient micropore transitions smoothly from the large diameter end to the small diameter end.

[0021] Optionally, the catalyst 1 is a VW-Ti / ZrO2 composite honeycomb catalyst.

[0022] Optionally, the second catalyst is a W-Mn-Ce-Ti / Al2O3 catalyst.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects:

[0024] During use, since the SCR-A catalytic zone and the SCR-B catalytic zone are arranged in the SCR denitration reactor, the SCR-A catalytic zone absorbs the hot gas in the preheating section II and performs denitration treatment. At the same time, the SCR-B catalytic zone absorbs the hot gas in the denitration adsorption section and performs denitration treatment. Since the denitration adsorption section is arranged close to the preheating section II, the hot gas flowing from the preheating section I to the preheating section II is sucked by negative pressure when passing through the denitration adsorption section, thereby avoiding cross-flow from the preheating section I to the preheating section II. The gas in the preheating section I enters the SCR-B catalytic zone for denitration treatment. While preventing cross-flow, the SCR denitration reactor can simultaneously perform denitration treatment on the gases in the preheating section I and the preheating section II, thereby improving the denitration efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work.

[0026] Figure 1 This is a schematic structural diagram of the SCR denitration reactor of the present invention;

[0027] Figure 2 This is a top view of the SCR denitration reactor structure of the present invention;

[0028] Figure 3 Schematic diagram of the connection between the rotary kiln-grate and the SCR denitration reactor of the present invention;

[0029] Among them, 1. Rotary kiln; 2. Chain grate; 3. SCR denitrification reactor; 4. Blast drying section; 5. Exhaust drying section; 6. Preheating section I; 7. Preheating section II; 8. SCR-A catalytic zone; 9. SCR-B catalytic zone; 10. High-temperature flue; 11. Low-temperature flue; 12. Purified gas outlet 1; 13. Purified gas outlet 2; 15. Converging duct; 16. Composite air inlet; 17. Cross guide plate; 18. Bellows; 19. Independent branch pipe; 20. Functional partition; 21. Gradient micropore; 22. SCR-A side of functional partition; 23. SCR-B side of functional partition; 24. Catalyst 1; 25. Catalyst 2. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Figures 1 to 3 The present invention discloses an embedded denitrification reactor for zoned drainage of pelletizing flue gas, comprising a rotary kiln 1 and a chain grate 2. The feed end of the rotary kiln 1 is connected to the discharge end of the chain grate 2. The chain grate 2 is provided with a blast drying section 4, an exhaust drying section 5, a preheating section I 6, and a preheating section II 7 in sequence along the material conveying direction. The reactor also comprises:

[0033] SCR denitration reactor 3, SCR denitration reactor 3 includes SCR-A catalytic zone 8 and SCR-B catalytic zone 9, SCR-A catalytic zone 8 and SCR-B catalytic zone 9 are heat exchanged, and the air inlet end of SCR-A catalytic zone 8 is connected to the air outlet end of preheating section II 7;

[0034] The side of the preheating section I 6 close to the preheating section II 7 is the denitration adsorption section, and the outlet end of the denitration adsorption section is connected to the inlet end of the SCR-B catalytic zone 9. The side of the preheating section I 6 away from the preheating section II 7 is the straight-discharge section, and the outlet end of the straight-discharge section is connected to the outlet end of the exhaust drying section 5 and the inlet end of the chimney;

[0035] The gas outlet ends of the SCR-A catalytic zone 8 and the SCR-B catalytic zone 9 are connected to the gas inlet end of the exhaust drying section 5 after merging.

[0036] During use, since the SCR-A catalytic zone 8 and the SCR-B catalytic zone 9 are provided in the SCR denitration reactor 3, the SCR-A catalytic zone 8 absorbs the hot gas in the preheating section II 7 and performs denitration treatment, and at the same time, the SCR-B catalytic zone 9 absorbs the hot gas in the denitration adsorption section and performs denitration treatment. Since the denitration adsorption section is arranged close to the preheating section II 7, the hot gas flowing from the preheating section I 6 to the preheating section II 7 is sucked by negative pressure when passing through the denitration adsorption section, thereby avoiding cross-flow from the preheating section I 6 to the preheating section II 7. The gas in the preheating section I 6 enters the SCR-B catalytic zone 9 for denitration treatment. While preventing cross-flow, the SCR denitration reactor 3 can simultaneously perform denitration treatment on the gases in the preheating section I 6 and the preheating section II 7, thereby improving the denitration efficiency.

[0037] The core of the present invention is to construct a zoned denitrification system that is deeply compatible with the chain grate-rotary kiln process. Through the coordinated design of shell waste heat recovery-graded reaction-embedded gas path, the coordinated treatment of differentiated flue gas and efficient energy utilization are achieved.

[0038] As an optional embodiment, a plurality of bellows 18 are connected to the bottom of the chain grate 2, and the outlet ends of the plurality of bellows 18 located in the preheating section II 7 are connected to the inlet end of the high-temperature flue 10 through an independent branch pipe 19, and the outlet end of the high-temperature flue 10 is connected to the SCR-A catalytic zone 8.

[0039] As an optional embodiment, several wind boxes 18 located in the denitrification adsorption section are connected to the air inlet end of the low-temperature flue 11 through another independent branch pipe 19, and the air outlet end of the low-temperature flue 11 is connected to the air inlet end of the SCR-B catalytic zone 9.

[0040] As an optional embodiment, the SCR-A catalytic zone 8 is a cylindrical structure, and a catalyst 24 is provided in the SCR-A catalytic zone 8;

[0041] The SCR-B catalytic zone 9 includes a heat exchange sleeve and a denitrification tube. The heat exchange sleeve is sleeved on the outside of the SCR-A catalytic zone 8. The heat exchange sleeve and the SCR-A catalytic zone 8 are heat exchanged. The air inlet end of the heat exchange sleeve is connected to the air outlet end of the low-temperature flue 11, and the air outlet end of the heat exchange sleeve is connected to the air inlet end of the denitrification tube. The denitrification tube is provided with a catalyst 25.

[0042] The outlet end of the purified gas outlet 2 13 of the denitrification cylinder and the purified gas outlet 1 12 of the SCR-A catalytic zone 8 are simultaneously connected to the air inlet end of the confluence pipe 15, and the outlet end of the confluence pipe 15 is connected to the exhaust drying section 5 through the composite air inlet 16.

[0043] As an optional embodiment, a cross guide plate 17 is provided in the confluence pipe 15 , and the cross guide plate 17 is used to evenly mix the two gases discharged from the purified gas outlet 2 13 and the purified gas outlet 1 12 .

[0044] The SCR denitration reactor 3 is internally divided into an SCR-A catalytic zone 8 and an SCR-B catalytic zone 9. The core of the SCR-A catalytic zone 8 is the SCR-B catalytic zone 9. The SCR denitration reactor 3 employs a unique sleeve-type structure. The SCR-B catalytic zone 9 comprises a heat exchange sleeve and a denitration sleeve. The heat exchange sleeve surrounds the SCR-A catalytic zone 8 to form a hollow shell, which forms an independent annular flue. This shell is made of a high-temperature resistant composite material, and its inner wall closely adheres to the outer surface of the SCR-A catalytic zone 8 to achieve efficient heat conduction.

[0045] The preheating section II 7 generates high-temperature flue gas with a temperature range of 400-500°C. The high-temperature flue gas directly enters the SCR-A catalytic zone 8 for denitrification. After denitrification, the gas is transported to the exhaust drying section, and the residual heat is used to assist in material drying. The preheating section I 6 generates low-temperature flue gas with a temperature range of 220-260°C. The low-temperature flue gas flows through the annular shell flue formed between the heat exchange sleeve and the SCR-A catalytic zone 8. When the flue gas flows through the periphery of the SCR-A catalytic zone 8, the inner wall of the shell directly absorbs the residual heat released by the reaction of the SCR-A catalytic zone 8. Its surface temperature is 380-480°C, causing the flue gas temperature gradient to rise to 280-320°C. The heated flue gas then enters the denitrification cylinder of the adjacent SCR-B catalytic zone 9 for denitrification. The purified gas returns to the exhaust drying section through the reflux pipe, forming an embedded heat exchange-closed-loop gas path self-balancing system, which simultaneously solves the cross-gas problems caused by insufficient activity of low-temperature flue gas and negative pressure fluctuations, and achieves a dual improvement in denitrification efficiency and process stability.

[0046] Multiple sets of wind boxes 18 are symmetrically arranged on both sides of the chain grate 2 to accommodate the high flow characteristics of high-temperature flue gas. The independent flue design further reduces temperature and velocity fluctuations in the mixed flue gas. Rectifier grilles are installed at the outlet of each partition, with their diversion angles matching the airflow direction of the corresponding process section. For example, the diversion angle in the drying section is 10°-20°, and in the recirculation section it is 5°-15°. By optimizing the flow field distribution, local eddies are reduced and the uniformity of gas distribution is improved.

[0047] As an optional embodiment, a functional partition 20 is provided between the heat exchange sleeve and the denitrification cylinder, and gradient micropores 21 are opened on the functional partition 20.

[0048] As an optional embodiment, the large diameter end of the gradient micropore 21 is disposed close to the functional separator SCR-B side 23 , and the small diameter end of the gradient micropore 21 is disposed close to the functional separator SCR-A side 22 .

[0049] As an optional embodiment, the large diameter end of the gradient micropore 21 is 2 mm, the small diameter end of the gradient micropore 21 is 0.5 mm, and the gradient micropore 21 smoothly transitions from the large diameter end to the small diameter end.

[0050] The partition isolation inside the SCR denitrification reactor 3 is achieved by a functional partition 20 with gradient micropores 21. The gradient micropores 21 can be designed to allow a small amount of airflow to penetrate to balance the pressure difference while avoiding complete crosstalk of the gas path.

[0051] As an optional embodiment, the catalyst 24 is a VW-Ti / ZrO2 composite honeycomb catalyst.

[0052] VW-Ti / ZrO2 composite honeycomb catalyst has a porosity of ≥65% and a specific surface area of ≥80m 2 / g, operating temperature window 380-430℃.

[0053] As an optional embodiment, the catalyst 25 is a W-Mn-Ce-Ti / Al2O3 catalyst.

[0054] The porosity of the W-Mn-Ce-Ti / Al2O3 catalyst is ≥70%, the specific surface area is ≥100m2 / g, and the operating temperature window is 280-320℃.

[0055] The activity retention rate of VW-Ti / ZrO2 composite honeycomb catalyst and W-Mn-Ce-Ti / Al2O3 catalyst after high temperature impact at 800℃ is ≥85%, and the service life is ≥25000h.

[0056] The optimized gas path design further enhances system efficiency. The flue gas from the preheating section is classified and processed through independent paths to avoid turbulence in the temperature and flow fields after mixing. At the same time, the return gas from the SCR-B catalytic zone 9 is evenly injected into the exhaust drying section 5 through a multi-point air distribution device. The multi-point air distribution device is a prior art and will not be described in detail. The purified gas from the SCR-B catalytic zone 9 returns to the exhaust drying section 5 through the return pipe 15 for material drying. At the same time, the low-temperature flue gas at the inlet of the SCR-B catalytic zone 9 absorbs the waste heat from the SCR-A catalytic zone 8 through the shell and heats up to 280-320°C, achieving self-balancing of the temperature difference between the preheating section I 6 and the preheating section II 7, thereby reducing the overall coal consumption of the system. In addition, the catalyst is designed to take into account both anti-sintering and anti-poisoning capabilities. After a high-temperature shock of 800°C, it can still maintain ≥85% of its initial activity, significantly extending its service life to 25,000 hours.

[0057] The ammonia injection system in the catalytic zone utilizes a zoned management strategy. A heat-resistant ammonia injection grid is installed at the interface between the high-temperature flue and the SCR-A catalytic zone 8. The high-temperature zone's ammonia injection grid is constructed of heat-resistant materials, and the ammonia-nitrogen molar ratio is dynamically adjusted based on the inlet concentration. An ammonia injection system is installed at the end of the annular shell flue and at the inlet of the SCR-B catalytic zone 9. The low-temperature zone's ammonia injection system reduces the ammonia-nitrogen ratio to minimize byproduct formation. The ammonia injection rate has a fast response time, adapting to transient fluctuations in flue gas composition. The ammonia injection system and its configuration are conventional in the field and are therefore not detailed here.

[0058] The catalyst selection takes into account both anti-sintering and anti-poisoning capabilities. A high-activity formula is used in the high-temperature zone, and anti-sulfur performance is enhanced in the low-temperature zone to ensure stable activity over a wide temperature range.

[0059] Regarding equipment maintenance, the catalyst replacement cycle is optimized based on operating conditions, and the independent zoning design allows for maintenance in individual zones without impacting overall system operation. Furthermore, a waste heat recovery module recycles heat from the denitrified gas back into the drying stage, reducing process energy consumption and improving energy efficiency.

[0060] In practical application, the system's closed-loop design and zoning control strategy significantly improved denitrification efficiency and stability. Cross-flow in the preheating section was effectively suppressed, flow field turbulence caused by excess flue gas was significantly reduced, and the rate of catalyst activity decay was slowed. Denitrification efficiency was increased to a high level, ammonia slip rates were stabilized at a low level, and system pressure drop was significantly optimized. Furthermore, waste heat recovery reduced external energy demand, improving both economic and environmental performance.

[0061] The technical advantages of this invention are reflected in the comprehensive improvement of denitrification efficiency and system stability. Compared with the traditional scheme: in terms of denitrification efficiency, the denitrification efficiency of the flue gas from the preheating stage II is increased from 80%-85% to more than 95%, and the denitrification efficiency of the flue gas from the preheating stage I 6 is also increased from 60%-65% to more than 95%; in terms of by-product production, the concentration of N2O by-products after denitrification of the flue gas from the preheating stage II 7 is increased from 30-50mg / m 3 Reduce to 5 mg / m 3 the following.

[0062] Through the collaborative design of partition embedding, closed-loop control and dynamic balance, the present invention realizes the efficient and stable operation of the SCR denitrification system in the chain grate-rotary kiln process, providing an innovative solution for the green transformation of the steel industry, combining environmental value and economy.

[0063] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0064] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. An embedded denitrification reactor for zoned drainage of pelletizing flue gas, comprising a rotary kiln (1) and a chain grate (2), wherein the feed end of the rotary kiln (1) is connected to the discharge end of the chain grate (2), and the chain grate (2) is sequentially provided with a blast drying section (4), an exhaust drying section (5), a preheating section I (6), and a preheating section II (7) along the material conveying direction, characterized in that: Also includes: An SCR denitration reactor (3), the SCR denitration reactor (3) comprising an SCR-A catalytic zone (8) and an SCR-B catalytic zone (9), the SCR-A catalytic zone (8) and the SCR-B catalytic zone (9) being arranged for heat exchange, the air inlet end of the SCR-A catalytic zone (8) being in communication with the air outlet end of the preheating section II (7); The side of the preheating section I (6) close to the preheating section II (7) is a denitration adsorption section, the outlet end of the denitration adsorption section is connected to the inlet end of the SCR-B catalytic zone (9), and the side of the preheating section I (6) away from the preheating section II (7) is a straight-discharge section, the outlet end of the straight-discharge section is connected to the outlet end of the exhaust drying section (5) and the inlet end of the chimney; The gas outlets of the SCR-A catalytic zone (8) and the SCR-B catalytic zone (9) are connected to the gas inlet of the exhaust drying section (5) after merging.

2. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 1, characterized in that: The bottom of the chain grate (2) is connected to a plurality of wind boxes (18), and the air outlet ends of the plurality of wind boxes (18) located in the preheating section II (7) are connected to the air inlet end of the high-temperature flue (10) through independent branch pipes (19), and the air outlet end of the high-temperature flue (10) is connected to the SCR-A catalytic zone (8).

3. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 2, characterized in that: The plurality of wind boxes (18) located in the denitration adsorption section are connected to the air inlet end of the low-temperature flue (11) through another independent branch pipe (19), and the air outlet end of the low-temperature flue (11) is connected to the air inlet end of the SCR-B catalytic zone (9).

4. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 3, characterized in that: The SCR-A catalytic zone (8) is a cylindrical structure, and a catalyst 1 (24) is provided in the SCR-A catalytic zone (8); The SCR-B catalytic zone (9) includes a heat exchange sleeve and a denitrification tube. The heat exchange sleeve is sleeved on the outside of the SCR-A catalytic zone (8). The heat exchange sleeve and the SCR-A catalytic zone (8) are heat exchanged. The air inlet end of the heat exchange sleeve is connected to the air outlet end of the low-temperature flue (11). The air outlet end of the heat exchange sleeve is connected to the air inlet end of the denitrification tube. The denitrification tube is provided with a catalyst 2 (25). The outlet end of the purified gas outlet 2 (13) of the denitrification cylinder and the purified gas outlet 1 (12) of the SCR-A catalytic zone (8) are simultaneously connected to the air inlet end of the confluence pipe (15), and the outlet end of the confluence pipe (15) is connected to the exhaust drying section (5) through the composite air inlet (16).

5. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 4, characterized in that: A cross guide plate (17) is provided in the confluence pipe (15), and the cross guide plate (17) is used to evenly mix the two gases discharged from the purified gas outlet 2 (13) and the purified gas outlet 1 (12).

6. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 4, characterized in that: A functional partition (20) is provided between the heat exchange sleeve and the denitration cylinder, and gradient micropores (21) are provided on the functional partition (20).

7. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 6, characterized in that: The large diameter end of the gradient micropore (21) is arranged close to the functional separator SCR-B side (23), and the small diameter end of the gradient micropore (21) is arranged close to the functional separator SCR-A side (22).

8. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 7, characterized in that: The large diameter end of the gradient micropore (21) is 2 mm, the small diameter end of the gradient micropore (21) is 0.5 mm, and the gradient micropore (21) smoothly transitions from the large diameter end to the small diameter end.

9. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 4, characterized in that: The catalyst one (24) is a VW-Ti / ZrO2 composite honeycomb catalyst.

10. The embedded denitrification reactor for zoned drainage of pelletized flue gas according to claim 4, characterized in that: The catalyst 2 (25) is a W-Mn-Ce-Ti / Al2O3 catalyst.

Images