Off-line energy-saving thermal desorption device for flue gas low-temperature denitration catalyst

Abstract

The utility model discloses an off-line energy-saving thermal desorption device for a flue gas low-temperature denitration catalyst, and mainly relates to the field of flue gas low-temperature denitration. Comprising a smoke inlet pipeline, a smoke outlet pipeline and a hot air pipeline, the smoke inlet pipeline is provided with a standby reaction bin and a plurality of main reaction bins which are communicated, catalyst modules are arranged in the standby reaction bin and the main reaction bins, the hot air pipeline is communicated with a plurality of hot air branch pipes, and the hot air pipeline is provided with an air distribution assembly used in cooperation with the hot air branch pipes. Thermal desorption ring pipes communicated with the hot air branch pipes are arranged in the standby reaction bin and the main reaction bin, and the bottoms of the thermal desorption ring pipes are communicated with a plurality of thermal desorption branch pipes arranged towards the catalyst module. The low-temperature catalyst thermal desorption device has the beneficial effects that the technical problems that the energy consumption is high and the normal production of a coke oven is easily influenced during the thermal desorption of the existing low-temperature catalyst can be solved, the thermal desorption effect is greatly improved, and the energy consumption and the cost of the thermal desorption are reduced.

Description

Technical Field

[0001] The utility model relates to the field of low-temperature flue gas denitration, in particular to an offline energy-saving thermal analysis device for a low-temperature flue gas denitration catalyst. Background Art

[0002] The coking industry is a crucial component of the coal chemical industry, an upstream sector of the steel industry, and a major polluting industry. Flue gas emissions from the coking industry are particularly significant. Coking companies primarily utilize coke oven technology, which produces large amounts of flue gas containing numerous pollutants, such as nitrogen oxides (NOx). NOx in coke oven flue gas can contribute to environmental problems such as acid rain and photochemical smog. With the continuous improvement of environmental laws and regulations and the increasing awareness of environmental protection, domestic coking companies must adopt denitrification technologies to reduce nitrogen oxide emissions in flue gas in order to reduce environmental pollution. Currently, the most commonly used flue gas denitrification technology is Selective Catalytic Reduction (SCR).

[0003] SCR technology primarily uses ammonia as a reducing agent. Under the action of a catalyst at a certain temperature, it reduces NOx in the flue gas to produce ammonia and water. In SCR system design, flue gas temperature is a key operating parameter for catalyst selection. SCR technology requires high efficiency and stability at high temperatures (320-400°C). Improvements to SCR denitrification catalysts have enabled the reaction temperature of medium- and low-temperature catalysts to be reduced to 190-320°C.

[0004] Compared with the flue gas parameters of thermal power plants, the temperature of coke oven flue gas is relatively low, generally below 250°C. If blast furnace gas is used to heat the coke oven, the flue gas temperature will be even lower than 200°C. Due to the low temperature of coke oven flue gas, high-temperature denitrification is not suitable. Therefore, the current coke oven flue gas mainly adopts medium and low temperature denitrification technology. However, when the flue gas temperature is below 250°C, the SO2 in the flue gas will be converted into SO3 under the action of the denitrification catalyst. Ammonia and SO3 react and easily generate ammonium bisulfate. Ammonium bisulfate is very easy to deliquesce and adheres to the catalyst surface, reducing the effective contact area between the flue gas and the catalyst, seriously affecting the efficiency of the catalyst, and also causing catalyst blockage and flue corrosion.

[0005] The SO2 in coke oven flue gas mainly comes from H2S in the coke oven heating fuel and SO2 produced by the combustion of organic sulfur. Due to the low temperature of coke oven flue gas, ammonium bisulfate is easily attached to the catalyst surface. The conventional practice is to set up a separate flue gas heating system to heat the flue gas and then perform online thermal decomposition on the catalyst.

[0006] Thermal decomposition is to provide 340-400℃ high-temperature thermal decomposition gas to the catalyst in the denitrification device. The high-temperature gas sublimates ammonium bisulfate and decomposes the ammonium bisulfate adhering to the catalyst surface. After the ammonium bisulfate sublimates, it is discharged with the flue gas. A high-temperature thermal decomposition generally lasts 12-24 hours. There are two common methods for thermal decomposition: one is to heat the coke oven flue gas to 340-400℃ in a direct-fired furnace. However, the energy consumption of heating the flue gas as a whole is large, and the waste heat recovery rate is not high, resulting in a huge waste of energy and increased operating costs. In addition, the increased flue gas temperature deviates from the optimal temperature reaction range of the medium and low temperature catalyst, resulting in reduced catalyst efficiency during thermal decomposition and prone to NOx exceeding the standard. The second is to shut down the coke oven and stop the flue gas from passing through the denitrification reactor. At this time, the high-temperature gas generated by combustion in the gas heating furnace is mixed with cold air to become a high-temperature thermal decomposition gas in the range of 340-400℃ to pyrolyze the catalyst. However, this thermal decomposition method requires frequent shutdown of the coke oven, which does not conform to the actual production schedule and coke oven process flow. The shutdown causes relatively large economic losses.

[0007] Therefore, how to achieve energy saving during thermal decomposition of low-temperature denitrification catalyst of coke oven flue gas without interfering with coke oven production and nitrogen oxide control is a technical problem that needs to be solved urgently. Utility Model Content

[0008] The purpose of the utility model is to provide an offline energy-saving thermal analysis device for flue gas low-temperature denitration catalyst, which can solve the technical problems of high energy consumption and easy impact on the normal production of coke ovens during the existing low-temperature catalyst thermal analysis, and realize fast and accurate thermal analysis operation of the low-temperature catalyst without stopping the coke oven, greatly improving the effect of thermal analysis and reducing the energy consumption and cost of thermal analysis.

[0009] In order to achieve the above-mentioned purpose, the present invention is realized through the following technical solutions:

[0010] An offline energy-saving thermal analysis device for a low-temperature denitrification catalyst for flue gas comprises a smoke inlet pipe, a smoke outlet pipe, and a hot air duct, wherein the smoke inlet pipe is provided with a connected spare reaction chamber and multiple main reaction chambers, the spare reaction chamber and the multiple main reaction chambers are both connected to the smoke outlet pipe, and catalyst modules are both provided in the spare reaction chamber and the main reaction chamber, the hot air duct is provided with multiple hot air branch pipes, and the multiple hot air branch pipes are respectively connected to the spare reaction chamber and the main reaction chamber, the hot air duct is provided with an air distribution component for use with the multiple hot air branch pipes, the spare reaction chamber and the main reaction chamber are both provided with a thermal analysis loop pipe connected to the hot air branch pipe, and the bottom of the thermal analysis loop pipe is connected with multiple thermal analysis branches arranged toward the catalyst module.

[0011] Furthermore, the air distribution component includes a rotating disk rotatably connected to the inside of the hot air duct, the rotating disk is provided with a plurality of ventilation holes, the side wall of the hot air duct located above the rotating disk is provided with a plurality of air outlets connected to the hot air branch pipe, and the rotating disk is provided with an air distribution plate used in conjunction with the air outlet.

[0012] Furthermore, the cross section of the air distribution plate is arc-shaped, and the air distribution plate is provided with an air distribution port used in conjunction with the air outlet.

[0013] Furthermore, a rotating shaft and an air distribution motor for driving the rotating shaft to rotate are provided in the hot air duct, and the rotating disk is fixedly connected to the rotating shaft.

[0014] Furthermore, the thermal decomposition branch pipe is connected to a plurality of inclined thermal decomposition side pipes.

[0015] Furthermore, the hot air duct is provided with a connected hot air furnace, and the hot air furnace is provided with a connected combustion-supporting pipe and a temperature-regulating pipe.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. The utility model sets a spare reaction chamber and a main reaction chamber between the smoke inlet pipe and the smoke outlet pipe, and catalyst modules are set inside the two chambers. When the catalyst module in a main reaction chamber needs to be subjected to thermal desorption treatment, the main reaction chamber is closed and the spare reaction chamber is opened at the same time, so that the flue gas passes through the spare reaction chamber for denitration treatment, and the hot air in the hot air pipe is passed into the main reaction chamber that needs thermal desorption through the hot air branch pipe, so as to realize rapid thermal desorption treatment of the low-temperature catalyst module in the main reaction chamber. The thermal desorption process will not affect the normal denitration treatment of the flue gas, and there is no need to heat the flue gas. Under the premise of ensuring the normal denitration treatment of the flue gas, the energy consumption of thermal desorption is greatly reduced, the interference with the normal production of the coke oven is reduced, and the flue gas treatment cost of the enterprise is reduced;

[0018] 2. The hot air duct is equipped with an air distribution component used in conjunction with multiple hot air branch pipes, so that the hot air can selectively enter the main reaction chamber or the spare reaction chamber that requires thermal desorption. During thermal desorption, the hot air enters the thermal desorption ring pipe through the hot air branch pipe and is evenly distributed to various positions of the catalyst module through multiple thermal desorption branch pipes at the bottom of the thermal desorption ring pipe, so that the ammonium bisulfate accumulated at various positions of the catalyst module is quickly decomposed, ensuring the denitrification catalytic efficiency of the catalyst module and greatly improving the thermal desorption effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Attachment Figure 1 It is a schematic diagram of an application scenario of the present utility model.

[0020] Attachment Figure 2 It is a schematic diagram of the three-dimensional structure of the hot air duct of the utility model.

[0021] Attachment Figure 3 It is a right side view of the hot air duct of the present utility model.

[0022] Attachment Figure 4 This utility model is attached Figure 3 Cross-sectional view in the AA direction.

[0023] Attachment Figure 5 This utility model is attached Figure 4 Cross-sectional view along the BB direction.

[0024] Reference numerals shown in the accompanying drawings:

[0025] 1. Smoke inlet duct; 2. Smoke outlet duct; 3. Hot air duct; 4. Spare reaction chamber; 5. Main reaction chamber; 6. Catalyst module; 7. Hot air branch pipe; 8. Thermal desorption ring pipe; 9. Thermal desorption branch pipe; 10. Rotating plate; 11. Ventilation hole; 12. Air outlet; 13. Air distribution plate; 14. Air distribution port; 15. Rotating shaft; 16. Air distribution motor; 17. Thermal desorption side pipe; 18. Hot air furnace; 19. Combustion-supporting pipe; 20. Temperature control pipe. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the contents of this invention, those skilled in the art may make various changes or modifications to the present invention, and that these equivalent forms also fall within the scope defined in this application.

[0027] Reference Figure 1The utility model is an offline energy-saving thermal analysis device for low-temperature denitration catalyst of flue gas. The main structure includes a smoke inlet pipe 1, a smoke outlet pipe 2, and a hot air pipe 3. The smoke generated by the coke oven enters the denitration reaction chamber through the smoke inlet pipe 1 for denitration treatment. The smoke after denitration treatment is discharged from the smoke outlet pipe 2. The hot air generated by the existing hot air furnace 18 and other heating equipment enters the denitration reaction chamber through the hot air pipe 3 to perform thermal analysis on the low-temperature catalyst. The smoke inlet pipe 1 is provided with a connected spare reaction chamber 4 and multiple main reaction chambers 5. The spare reaction chamber 4 and the main reaction chamber 5 have the same structure. When the flue gas is undergoing denitration treatment, the spare reaction chamber 4 is closed, and the multiple main reaction chambers are closed. The reaction chamber 5 is opened, and the flue gas enters multiple main reaction chambers 5 for denitration treatment. When the denitration efficiency of the low-temperature catalyst in a main reaction chamber 5 decreases, the standby reaction chamber 4 is opened and the main reaction chamber 5 is closed, so that the flue gas passes through the standby reaction chamber 4 for denitration treatment, so that the main reaction chamber 5 that requires thermal desorption is in an offline state. In this state, the hot air introduced into the hot air duct 3 is used to perform thermal desorption treatment on the offline main reaction chamber 5, which will not interfere with the normal denitration of the flue gas, does not require the coke oven to be shut down, and does not require the flue gas to be heated as a whole, greatly reducing the interference with the normal production of the coke oven, reducing the energy consumption of thermal desorption, and effectively reducing the cost of flue gas treatment;

[0028] The standby reaction chamber 4 and multiple main reaction chambers 5 are all connected to the smoke outlet pipe 2. Preferably, the tops of the standby reaction chamber 4 and the main reaction chamber 5 are connected to the smoke inlet pipe 1, and the bottoms are evenly connected to the smoke outlet pipe 2, so that the inlet and outlet of the smoke are smoother. The standby reaction chamber 4 and the main reaction chamber 5 are both provided with a catalyst module 6. The catalyst module 6 is located between the smoke inlet pipe 1 and the smoke outlet pipe 2, so that the incoming smoke is discharged after being processed by the catalyst module 6. The catalyst module 6 is generally a catalyst material that plays a catalytic role in a low-temperature environment and is generally applicable to temperatures below 250 degrees. , which is convenient for denitrification of coke oven flue gas and thermal power plant flue gas. The hot air duct 3 is connected with a plurality of hot air branch pipes 7, and the plurality of hot air branch pipes 7 are respectively connected with the standby reaction bin 4 and the main reaction bin 5. The hot air in the hot air duct 3 enters the standby reaction bin 4 or the main reaction bin 5 through the plurality of hot air branch pipes 7. The hot air duct 3 is provided with an air distribution component used in conjunction with the plurality of hot air branch pipes 7. The air distribution component is used to control the distribution of the hot air so that the hot air only enters the bin body that needs thermal decomposition, thereby achieving full utilization of the hot air and reducing the loss of the hot air. Figure 2 and Figure 3The standby reaction chamber 4 and the main reaction chamber 5 are both provided with a thermal decomposition loop pipe 8 connected to the hot air branch pipe 7. The thermal decomposition loop pipe 8 is located above the catalyst module 6. The bottom of the thermal decomposition loop pipe 8 is connected to multiple thermal decomposition branch pipes 9 arranged toward the catalyst module 6. This structure allows the hot air to be evenly distributed at various positions of the catalyst module 6 through the thermal decomposition loop pipe 8 and the thermal decomposition branch pipe 9 at the bottom, so that the ammonium bisulfate accumulated at various positions of the catalyst module 6 can be quickly and accurately decomposed, thereby ensuring sufficient contact between various positions of the catalyst module 6 and the flue gas, ensuring the catalytic efficiency of the catalyst module 6, and further improving the effect of thermal decomposition.

[0029] Preferably, refer to Figure 4 The air distribution component includes a rotating disk 10 rotatably connected to the inside of the hot air duct 3. The rotating disk 10 is rotatably connected to the inside of the hot air duct 3 through a bearing to block the hot air duct 3. The rotating disk 10 is provided with a plurality of through ventilation holes 11, so that the hot air passes through the ventilation holes 11 and enters the hot air branch pipe 7. The side wall of the hot air duct 3 above the rotating disk 10 is provided with a plurality of air outlets 12 connected to the hot air branch pipe 7. The rotating disk 10 is provided with an air distribution plate 13 used in conjunction with the air outlet 12. The air distribution plate 13 can open a certain air outlet 12 when the rotating disk 10 rotates, so that the hot air only enters the hot air branch pipe 7 that needs thermal decomposition, thereby realizing accurate distribution of hot air, simple structure, more accurate air distribution process, ensuring the efficiency of thermal decomposition, and reducing the cost caused by hot air loss.

[0030] Preferably, refer to Figure 5 The cross section of the air distribution plate 13 is arc-shaped, and the arc-shaped structure can better fit the inner wall of the hot air duct 3, so that the air outlet 12 on the inner wall of the hot air duct 3 is sealed more tightly. The air distribution plate 13 is provided with an air distribution port 14 used in conjunction with the air outlet 12. When the air distribution plate 13 is driven to rotate by the rotating disk 10, when the air distribution port 14 is aligned with a certain air outlet 12, the hot air passing through the ventilation hole 11 on the rotating disk 10 can enter the corresponding hot air branch pipe 7, further improving the convenience and accuracy of air distribution control.

[0031] Preferably, a rotating shaft 15 and an air distribution motor 16 for driving the rotating shaft 15 to rotate are provided in the hot air duct 3. The rotating shaft 15 is fixed to the output shaft of the air distribution motor 16 by welding or bolts, and the rotating disk 10 is welded or bolted to the rotating shaft 15. Such a structure utilizes the rotation of the air distribution motor 16 to realize automatic control of the air distribution, further reduces the difficulty of the air distribution, and improves the efficiency and convenience of the thermal analysis operation.

[0032] Preferably, the thermal decomposition branch pipe 9 is connected to a plurality of inclined thermal decomposition side pipes 17, and the inclined thermal decomposition side pipes 17 can blow hot air toward various positions of the catalyst module 6, thereby further improving the uniformity of the distribution of the hot air on the catalyst module 6, and further improving the effect and uniformity of the thermal decomposition.

[0033] Preferably, the hot air duct 3 is provided with a connected hot air furnace 18, and the hot air furnace 18 is provided with a connected combustion-supporting duct 19 and a temperature-regulating duct 20. Preferably, the combustion-supporting duct 19 is connected to the outside air, and the temperature-regulating duct 20 is connected to the flue gas after dust removal, so that the treated flue gas can be recycled, thereby improving the utilization rate of the heat in the flue gas and further reducing the cost of thermal analysis.

[0034] Working principle: The utility model sets a spare reaction chamber 4 and a main reaction chamber 5 between the smoke inlet pipe 1 and the smoke outlet pipe 2, and a catalyst module 6 is set inside both. When the catalyst module 6 in a certain main reaction chamber 5 needs to be subjected to thermal analysis, the main reaction chamber 5 is closed and the spare reaction chamber 4 is opened at the same time, so that the flue gas passes through the spare reaction chamber 4 and undergoes denitration treatment. The hot air in the hot air pipe 3 is passed into the main reaction chamber 5 that needs thermal analysis through the hot air branch pipe 7, so as to realize rapid thermal analysis treatment of the low-temperature catalyst module 6 in the main reaction chamber 5. The thermal analysis process will not affect the normal denitration treatment of the flue gas, and there is no need to heat the flue gas, thereby ensuring the normal denitration of the flue gas. Under the premise of denitrification treatment, the energy consumption of thermal analysis is greatly reduced, the interference with the normal production of the coke oven is reduced, and the enterprise's flue gas treatment cost is reduced; the hot air duct 3 is provided with an air distribution component used in conjunction with multiple hot air branch pipes 7, so that the hot air can selectively enter the main reaction chamber 5 or the spare reaction chamber 4 that requires thermal analysis. During thermal analysis, the hot air enters the thermal analysis ring pipe 8 through the hot air branch pipe 7, and is evenly distributed at various positions of the catalyst module 6 through multiple thermal analysis branch pipes 9 at the bottom of the thermal analysis ring pipe 8, so that the ammonium bisulfate accumulated at various positions of the catalyst module 6 is quickly decomposed, thereby ensuring the denitrification catalytic efficiency of the catalyst module 6 and greatly improving the effect of thermal analysis.

Claims

1. An off-line energy-saving thermal analysis device for flue gas low-temperature denitration catalyst, comprising a smoke inlet pipe (1), a smoke outlet pipe (2), and a hot air pipe (3), characterized in that: The smoke inlet pipe (1) is provided with a standby reaction chamber (4) and a plurality of main reaction chambers (5) that are connected. The standby reaction chamber (4) and the plurality of main reaction chambers (5) are both connected to the smoke outlet pipe (2). The standby reaction chamber (4) and the main reaction chamber (5) are both provided with a catalyst module (6). The hot air pipe (3) is provided with a plurality of hot air branch pipes (7) that are connected. The plurality of hot air branch pipes (7) are respectively connected to the standby reaction chamber (4) and the main reaction chamber (5). The hot air pipe (3) is provided with an air distribution component used in conjunction with the plurality of hot air branch pipes (7). The standby reaction chamber (4) and the main reaction chamber (5) are both provided with a thermal decomposition ring pipe (8) that is connected to the hot air branch pipe (7). The bottom of the thermal decomposition ring pipe (8) is connected with a plurality of thermal decomposition branch pipes (9) that are arranged toward the catalyst module (6).

2. The offline energy-saving thermal desorption device for flue gas low-temperature denitration catalyst according to claim 1, characterized in that: The air distribution component includes a rotating disk (10) rotatably connected to the inside of the hot air duct (3), the rotating disk (10) is provided with a plurality of ventilation holes (11), the side wall of the hot air duct (3) located above the rotating disk (10) is provided with a plurality of air outlets (12) connected to the hot air branch pipe (7), and the rotating disk (10) is provided with an air distribution plate (13) used in conjunction with the air outlets (12).

3. The offline energy-saving thermal desorption device for flue gas low-temperature denitration catalyst according to claim 2, characterized in that: The cross section of the air distribution plate (13) is arc-shaped, and the air distribution port (14) used in conjunction with the air outlet (12) is provided on the air distribution plate (13).

4. The offline energy-saving thermal desorption device for flue gas low-temperature denitration catalyst according to claim 2, characterized in that: A rotating shaft (15) and an air distribution motor (16) for driving the rotating shaft (15) to rotate are provided in the hot air duct (3), and the rotating disk (10) is fixedly connected to the rotating shaft (15).

5. The offline energy-saving thermal desorption device for flue gas low-temperature denitration catalyst according to claim 1, characterized in that: The thermal decomposition branch pipe (9) is connected to a plurality of inclined thermal decomposition side pipes (17).

6. The offline energy-saving thermal desorption device for flue gas low-temperature denitration catalyst according to claim 1, characterized in that: The hot air duct (3) is provided with a connected hot air furnace (18), and the hot air furnace (18) is provided with a connected combustion-supporting pipe (19) and a temperature-regulating pipe (20).

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