Purification treatment equipment and process for coke oven chimney waste gas

Abstract

The invention discloses purification treatment equipment and technology for coke oven chimney waste gas, and belongs to the technical field of waste gas treatment.The purification treatment equipment is based on the existing waste gas desulfurization and denitrification operation principle, and a plurality of annular desulfurization cavities distributed inside and outside are formed in a desulfurization tower; inlet raw waste gas is subjected to upward split-flow injection through the gas distribution assembly in rotary operation, a calcium-based desulfurizing agent is subjected to synchronous upward split-flow injection action in cooperation with the desulfurizing agent inlet pipe, and the narrow annular desulfurizing cavity is matched with a multi-point high-speed conveying mode so as to provide power for upward movement and diffusion of the waste gas. According to the present invention, the desulfurization agent and the waste gas can be completely mixed so as to carry out a reaction, the condition that the part of the desulfurization agent sinks without timely reaction can be effectively avoided, the desulfurization agent utilization rate can be improved, and the dust and the calcium sulfate precipitate can be separated and fall through the falling cavity by using the centrifugal channel at the top; and waste gas backflow and waste heat insulation are utilized to provide an efficient denitration environment.

Description

Technical Field

[0001] The present invention relates to the technical field of coke oven waste gas treatment, and more specifically to a purification treatment device and process for coke oven chimney waste gas. Background Art

[0002] A coke oven is a kiln that uses coal to make coke. A large amount of waste gas is generated during operation. In particular, the existing coke oven waste gas is connected to the coke oven waste gas for combustion treatment along with the desulfurization waste liquid medium, which causes a significant increase in waste gas volume and a doubling of pollutant concentration. It needs to be desulfurized before being discharged. For the treatment of coke oven waste gas, the traditional coke oven waste gas treatment system adopts the "dry desulfurization + dust removal + denitrification" process to achieve the reduction of waste gas pollutants. For related processes, please refer to the contents of publication number CN219942346U and publication number CN115715927A.

[0003] In the prior art, for the desulfurization and dust removal of waste gas, the desulfurizer is mostly directly introduced into a straight-through desulfurization tower together with the waste gas. After entering the desulfurization tower with a larger inner diameter, the waste gas diffuses to a large area around due to the reduced pressure. Due to the large volume of the tower body, the desulfurizer and the waste gas are not fully contacted and mixed, causing part of the calcium-based desulfurizer to sink before reacting in time, resulting in low desulfurization efficiency. When the pressure of the waste gas discharged upward is insufficient, the calcium sulfate precipitate produced by the reaction will also sink due to gravity. If the calcium sulfate precipitate is not separated and discharged, the sinking calcium sulfate precipitate will also affect the reaction effect of the desulfurizer and the waste gas.

[0004] In addition, for the denitrification treatment after desulfurization of exhaust gas, the existing method is to directly introduce high-temperature flue gas, use catalytic ceramic filter tubes as carriers for denitrification treatment, and directly discharge the exhaust gas after treatment. On the one hand, the high-temperature flue gas directly contacts the filter tube, and there is a large temperature difference between the two. Excessive temperature fluctuations will affect the reaction effect and the performance of the catalyst. On the other hand, the waste heat of the exhaust gas is not utilized.

[0005] Therefore, in response to the above problems, we propose the purification equipment and process of coke oven chimney exhaust gas. Summary of the invention

[0006] The purpose of the present invention is to solve the existing practical production problems and provide a purification treatment device and process for coke oven chimney exhaust gas compared with the prior art.

[0007] The purpose of the present invention can be achieved through the following technical solutions: a purification and treatment device for exhaust gas from a coke oven chimney, comprising a desulfurization tower and a denitrification tower, wherein a desulfurization sleeve is arranged inside the desulfurization tower, and the desulfurization sleeve comprises an outer ring cylinder, a middle ring cylinder and an inner ring cylinder which are sequentially sleeved and distributed from the outside to the inside, and a rotating column which runs through the inner ring cylinder is rotatably installed inside the inner ring cylinder, and a plurality of annular desulfurization cavities distributed from the outside to the inside are formed inside the desulfurization sleeve, and an air distribution assembly which is located at the bottom of the desulfurization sleeve and runs through the plurality of annular desulfurization cavities is fixedly installed at the lower end of the rotating column, and a distribution assembly which is adapted to the air distribution assembly and also runs through the plurality of annular desulfurization cavities is arranged at the lower end of the outer ring cylinder, and the distribution assembly is located above the air distribution assembly;

[0008] A heating channel in the middle of the denitrification tower and a plurality of insulation chambers distributed in an annular manner on the outside of the heating channel are fixedly installed inside the denitrification tower through a fixed plate. Each insulation chamber is provided with a plurality of filter chambers distributed in an annular manner and extending to the bottom thereof. The bottom end of the heating channel is connected to the filter chamber of each insulation chamber through a plurality of conducting pipes.

[0009] Furthermore, a reflux hood is installed on the top of the desulfurization tower, and the space between the reflux hood and the top of the desulfurization sleeve constitutes a centrifugal channel. A plurality of fan plates are distributed in an annular manner on the end wall of the rotating column located in the centrifugal channel, and a return chamber connected to the centrifugal channel is formed between the outer ring cylinder and the inner wall of the desulfurization tower.

[0010] Furthermore, the air distribution assembly includes a rotating disk which is coaxially arranged with the rotating column and has a return material gap reserved between it and the bottom of the desulfurization sleeve. A plurality of ventilation pipes which are inner and outer coupled and interconnected are provided at the bottom of the rotating disk. A plurality of injection pipes which pass through the rotating disk and extend to the bottom of the annular desulfurization chamber are fixedly installed in an annular manner on the ventilation pipe.

[0011] Furthermore, a plurality of fan flow plates corresponding to the positions of the plurality of annular desulfurization chambers are distributed in an annular manner from the inside to the outside at the upper end of the rotating disk, and the fan flow plates are arranged adjacent to the injection pipe and tilted backward.

[0012] Furthermore, the distribution assembly includes an annular tube located outside the bottom of the outer ring tube, on which are distributed a plurality of distribution pipes which are staggered and extend obliquely upward to a plurality of annular desulfurization chambers respectively. The distribution pipe is located above the injection pipe, and one end of the annular tube is connected to a desulfurizer inlet pipe.

[0013] Furthermore, sealing plates for embedding and installing the filter chamber are fixed at both ends of the insulation chamber. The filter chamber includes an outer filter sleeve and a ceramic filter tube inside it. The lower end wall of the outer filter sleeve is provided with an air inlet hole connected to the bottom of the insulation chamber.

[0014] Furthermore, the top of the insulation chamber is a closed structure, and the upper and lower sealing plates divide the inner part of the insulation chamber into an insulation cavity. A plurality of vents are provided on the upper sealing plate, and an outlet for connecting the insulation cavity and the denitrification tower is provided on the lower end wall of the insulation chamber.

[0015] The purification process of the exhaust gas from the coke oven chimney comprises the following steps:

[0016] S1. Desulfurization treatment: The original exhaust gas is rotated upward along the multiple annular desulfurization chambers of the desulfurization sleeve by the booster fan and the air distribution component. The distribution component is used to synchronously split and spray the calcium-based desulfurizer upward at the upper position of the original exhaust gas injection. The original exhaust gas drives the calcium-based desulfurizer to diffuse upward along the multiple annular desulfurization chambers for a long distance reaction to remove sulfur dioxide and other acidic media. This process generates calcium sulfate;

[0017] S2. Dust removal: The waste gas is passed upward into the centrifugal channel, and the dust and calcium sulfate precipitate generated by the reaction fall through the return cavity;

[0018] S3, Denitrification and Dust Removal: After the exhaust gas undergoes a desulfurization reaction in a fluidized state, it is passed into a heating channel for heating, and ammonia is sprayed into the top of the heating channel simultaneously. After the two are evenly distributed by the airflow, multiple filter chambers are used as carriers to efficiently remove nitrogen oxides and dust in the exhaust gas;

[0019] S4. Exhaust gas external insulation treatment: Before being discharged, the clean exhaust gas overflows from the top of multiple filter chambers and then flows back downward to the insulation chamber for insulation treatment.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] 1. The present invention is based on the existing operation principle of waste gas desulfurization and denitrification. Aiming at the problem of low desulfurization efficiency caused by insufficient reaction between desulfurizer and waste gas, an annular desulfurization chamber with multiple inner and outer outer configurations is arranged in the desulfurization tower. In the desulfurization and dust removal link, the original waste gas introduced is split and sprayed upward by a rotating air distribution component, and the calcium-based desulfurizer is synchronously split and sprayed upward in cooperation with the desulfurizer inlet pipe. The narrow annular desulfurization chamber is equipped with a multi-point high-speed conveying mode, the purpose of which is to provide the power for the waste gas to move upward and diffuse, which is conducive to the full mixing and reaction of the desulfurizer and the waste gas, and effectively avoids the situation where part of the desulfurizer sinks before reacting in time, thereby improving the utilization rate of the desulfurizer, and using the centrifugal channel at the top in cooperation with the fall-back chamber to achieve the separation of calcium sulfate precipitation and waste gas;

[0022] 2. A heating system and a heat preservation system are added to the denitrification tower. The exhaust gas after primary fluidized desulfurization is mixed with ammonia and heated up. After diversion and airflow uniformity, it enters the multi-compartment ceramic filter tube structure, which effectively improves the denitrification and dust removal effect. In addition, the existing ceramic filter tube structure is improved. The clean exhaust gas overflows from the top of multiple filter chambers and then flows back downward to the heat preservation chamber for heat preservation, thereby reducing the temperature difference between the exhaust gas and the filter chamber. The clean exhaust gas after heat exchange treatment enters the denitrification tower through multiple air outlets at the bottom of the heat preservation chamber, creating a high-temperature heating environment in the denitrification tower again, improving the utilization effect of waste heat of exhaust gas, thereby ensuring a good denitrification treatment environment and enhancing the denitrification and dust removal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the junction of the desulfurization tower and the denitration tower of the present invention;

[0024] Figure 2 It is a cross-sectional view of the junction of the desulfurization tower and the denitration tower of the present invention;

[0025] Figure 3 is a cross-sectional view of a desulfurization tower of the present invention;

[0026] Figure 4 A bottom view of the desulfurization sleeve of the present invention;

[0027] Figure 5 It is a schematic diagram of the structure of the joint between the air distribution assembly, the rotating column and the fan plate of the present invention;

[0028] Figure 6 It is a bottom view of the joint between the air distribution assembly, the rotating column and the fan plate of the present invention;

[0029] Figure 7 It is a structural schematic diagram of the cloth component of the present invention;

[0030] Figure 8 It is a schematic structural diagram of the junction of a pair of heat preservation chambers and a heating channel of the present invention;

[0031] Fig. 9 It is a cross-sectional view of the junction of the heat preservation chamber and the heating channel of the present invention;

[0032] Fig.10 It is a cross-sectional view of the junction of the heat preservation chamber and the filtering chamber of the present invention;

[0033] Fig.11 It is a process flow chart of the present invention.

[0034] Description of the numbers in the figure:

[0035] 1. Desulfurization tower; 2. Denitrification tower; 3. Air inlet pipe; 301. Branch pipe; 4. Air distribution assembly; 41. Rotating disk; 42. Ventilation pipe; 43. Injection pipe; 44. Fan flow plate; 5. Outer ring cylinder; 6. Middle ring cylinder; 7. Inner ring cylinder; 8. Guide cover; 9. Rotating column; 10. Desulfurizer inlet pipe; 11. Distribution assembly; 12. Backflow cover; 13. Fan flow plate; 14. Conversion flue; 15. Insulation chamber; 151. Air outlet; 16. Filter chamber; 161. Outer filter sleeve; 161. Ceramic filter tube; 17. Heating channel; 171. Separator; 18. Blocking plate; 181. Ventilation port; 19. Ammonia inlet pipe; 191. Diverter hole; 20. Exhaust pipe. DETAILED DESCRIPTION

[0036] The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0037] Example 1: In view of the problem in the prior art that the desulfurization efficiency is low due to insufficient reaction between the desulfurizer and the exhaust gas, the desulfurization equipment is optimized and improved, and the following technical solution is proposed:

[0038] See also Figure 1 The present invention discloses a coke oven chimney exhaust gas purification treatment device, please refer to Figure 1 , Figure 4 , including a desulfurization tower 1 and a denitration tower 2. The bottoms of the desulfurization towers 1 and 2 are both provided with conical ash hoppers. A desulfurization sleeve is provided inside the desulfurization tower 1. The desulfurization sleeve includes an outer ring tube 5, a middle ring tube 6, and an inner ring tube 7 which are sequentially sleeved from the outside to the inside. A rotating column 9 which runs through the inner ring tube 7 is rotatably installed. A plurality of annular desulfurization cavities distributed from the outside to the inside are formed in the desulfurization sleeve. The middle ring tube 6, the inner ring tube 7, and the guide cover 8 are fixedly installed with the inner wall of the desulfurization tower 1 through the partitions on both sides, so that the outer ring tube 5, the middle ring tube 6, and the inner ring tube 7 are in a fixed installation state, which is convenient for the original exhaust gas to be fully mixed with the calcium-based desulfurizer powder sprayed upward in the annular desulfurization cavity with a small gap;

[0039] See also Figure 3 , the lower end of the rotating column 9 is fixedly installed with an air distribution component 4 located at the bottom of the desulfurization sleeve and penetrating and distributed to multiple annular desulfurization cavities, and the lower end of the outer ring tube 5 is provided with a distribution component 11 adapted to the air distribution component 4 and also penetrating to multiple annular desulfurization cavities. The distribution component 11 is located above the air distribution component 4. A bearing tray is fixed at the conical ash hopper at the bottom end of the desulfurization tower 1 through multiple reinforcing rods. The air distribution component 4 is rotatably installed on the bearing tray through a connecting pipe, and the inner end of the air inlet pipe 3 is connected and installed with the connecting pipe through a rotating joint, so that the air distribution component 4 does not affect the continuous air supply during the rotation process;

[0040] Among them, see Figure 6 The air distribution assembly 4 includes a rotating disk 41 which is coaxially arranged with the rotating column 9 and has a return material gap reserved between the rotating disk 41 and the bottom of the desulfurization sleeve. The bottom end of the rotating disk 41 is provided with a plurality of vent pipes 42 which are connected to each other and are connected to each other. A plurality of injection pipes 43 which penetrate the rotating disk 41 and extend to the bottom of the annular desulfurization chamber are fixedly installed in an annular manner on the vent pipe 42. A plurality of fan flow sheets 44 which correspond to the positions of the plurality of annular desulfurization chambers are distributed in an annular manner from the inside to the outside on the upper end of the rotating disk 41. The fan flow sheets 44 are arranged adjacent to the injection pipes 43 and tilted backwards;

[0041] See also Figure 3 , Figure 4 as well as Figure 7 The distribution assembly 11 includes an annular tube located outside the bottom of the outer ring tube 5, and a plurality of distribution tubes are distributed on the annular tube, which are staggered and obliquely extended to a plurality of annular desulfurization chambers respectively. The distribution tube is located above the injection tube 43, and a desulfurizer inlet pipe 10 is connected to one end of the annular tube. The distribution tubes are distributed in an annular manner, and the inner and outer lengths are adapted to the annular desulfurization chambers distributed inside and outside, that is, the distribution tube with the outermost annular desulfurization chamber is the shortest, and gradually increases from the outside to the inside, and the distribution tubes distributed inside and outside are staggered with each other, and the number of distribution tubes decreases from the outside to the inside. A desulfurizer inlet pipe 10 is connected to one end of the annular tube, and the other end of the desulfurizer inlet pipe 10 is also connected to the calcium-based desulfurizer supply source through a booster fan.

[0042] See also Figure 3 The air inlet pipe 3 located outside the desulfurization tower 1 is fixedly connected to the ventilation pipe 42, and the air inlet pipe 3 is externally connected to a booster fan, which is connected to the coke oven flue through a pipeline. Multiple injection pipes 43 distributed in an annular manner extend from the outside to the inside to the bottom of multiple annular desulfurization chambers;

[0043] The air inlet pipe 3 is connected to one end of the desulfurizer inlet pipe 10 through the branch pipe 301, and part of the original exhaust gas is used as the conveying medium. Part of the exhaust gas has a certain carrying and conveying capacity, so that the calcium-based desulfurizer is evenly distributed and conveyed to multiple annular desulfurization chambers through multiple distribution pipes. The multiple distribution pipes are inclined upward and have upward power. Under the continuous push of the exhaust gas below, they can smoothly diffuse upward along the annular desulfurization chamber. The desulfurizer is thermally activated in the annular desulfurization chamber, and the specific surface area increases rapidly. It undergoes physical and chemical reactions with acidic substances such as sulfur dioxide in the exhaust gas, so that acidic substances such as sulfur dioxide in the exhaust gas are absorbed and purified, and sulfur dioxide and other acidic media are removed.

[0044] In view of the desulfurization reaction process, the internal space of the traditional straight-through desulfurization tower is divided into multiple annular desulfurization chambers with narrow spacing inside and outside, which is conducive to the diversion of the original exhaust gas and calcium-based desulfurizer directed upward. On the one hand, it is conducive to the full mixing of the desulfurizer and the exhaust gas for reaction. On the other hand, the narrow annular desulfurization chamber is equipped with the exhaust gas and calcium-based desulfurizer continuously transported upward. The purpose is to make the exhaust gas have the power to move upward and diffuse, effectively avoiding the situation where some calcium-based desulfurizers sink before reacting in time, and improving the utilization rate of the desulfurizer;

[0045] Also, see Figure 4 and Figure 5A plurality of annularly distributed fan flow pieces 44 are added to the rotating disk 41, and each fan flow piece 44 is arranged tilted backward near the injection pipe 43. When the air distribution component 4 rotates counterclockwise with the rotating column 9, the rotating direction of the rotating disk 41 is opposite to the tilt direction of the injection pipe 43. After the original exhaust gas is rotated and injected through the injection pipe 43, the exhaust gas is evenly diffused in the annular desulfurization chamber and moves upward. The fan flow pieces 44 rotating behind each injection pipe 43 are beneficial to the upward diversion and diffusion of the overflowing original exhaust gas. The plurality of fan flow pieces 44 rotating in a circle provide the exhaust gas with a centrifugal swirling force for further upward movement, which is beneficial to the full and even diffusion of the original exhaust gas in the entire annular desulfurization chamber, further improving the desulfurization reaction effect.

[0046] See also Figure 3 , Figure 5 A guide hood 8 with a tapered structure that is wide at the top and narrow at the bottom is fixedly installed on the top of the outer ring cylinder 5. A reflux hood 12 is installed on the top of the desulfurization tower 1. The space between the reflux hood 12 and the top of the desulfurization sleeve constitutes a centrifugal channel. A plurality of fan plates 13 are distributed in an annular manner on the end wall of the rotating column 9 located in the centrifugal channel. The reflux hood 12 is fixedly installed on the top of the desulfurization tower 1 and is narrow at the top and wide at the bottom and has a conical structure. A driving motor for rotating the rotating column 9 is fixed on the top of the desulfurization tower 1;

[0047] The setting of the guide hood 8 is beneficial to guiding the exhaust gas in multiple annular desulfurization chambers toward the middle of the top and into the middle position of the centrifugal channel. On the other hand, the setting of the guide hood 8 intercepts the calcium-based desulfurizer particles that have not reacted in time and the calcium sulfate precipitate generated by the partial reaction, so that the calcium-based desulfurizer particles that have not reacted in time and the calcium sulfate precipitate generated by the partial reaction can flow back to the annular desulfurization chamber under the action of the inclined surface inside the guide hood 8. This process is beneficial for the calcium-based desulfurizer particles that have not reacted in time to continue to react, and the fallen part of the calcium sulfate precipitate falls from the return material gap formed between the rotating disk 41 and the bottom of the desulfurization sleeve.

[0048] The exhaust gas carries most of the calcium sulfate precipitate into the centrifugal channel through the guide hood 8. Under the centrifugal movement of multiple fan plates 13, the exhaust gas is thrown toward the inner wall of the return hood 12. It should be added that a conical sleeve located above the guide hood 8 is fixed on the rotating column 9. The conical sleeve is wide at the top and narrow at the bottom. Multiple fan plates 13 are distributed in an annular manner on the conical sleeve, and the fan plates 13 are tilted on the conical sleeve. The tilt direction is opposite to the tilt direction of the fan plates 44. The fan plates 13 are arranged from bottom to top along the counterclockwise rotation direction. When the fan plates 13 rotate counterclockwise with the rotating column 9, the lower side of the fan plates 13 directly contacts the rising exhaust gas and centrifugally throws the exhaust gas outward, thereby improving the solid-gas separation effect and enhancing the purification capacity of the desulfurization tower.

[0049] A return cavity connected to the centrifugal channel is formed between the outer ring cylinder 5 and the inner wall of the desulfurization tower 1. Dust and calcium sulfate precipitate are thrown to the inner wall of the reflux hood 12 and fall through the return cavity. Finally, they are discharged through the conical ash hopper at the bottom of the desulfurization tower 1 together with the calcium sulfate precipitate falling from the return material gap. The exhaust gas after desulfurization treatment is connected to the top of the denitrification tower 2 through the conversion flue 14 installed on the top.

[0050] Example 2: This example optimizes and improves the existing denitration-dust removal structure as follows:

[0051] See also Figure 2 and Figure 8-Figure 10 A heating channel 17 in the middle of the denitrification tower 2 and a plurality of heat-insulating chambers 15 annularly distributed on the outside of the heating channel 17 are fixedly installed inside the denitrification tower 2 through a fixed plate. A plurality of filter chambers 16 are annularly distributed inside each heat-insulating chamber 15 and penetrate to the bottom thereof. The bottom end of the heating channel 17 is connected to the filter chamber 16 of each heat-insulating chamber 15 through a plurality of conducting pipes.

[0052] The heat preservation chamber 15 is a conical cylinder structure that is wide at the top and narrow at the bottom. The top of the heating channel 17 is connected to the conversion flue 14, and the top of the heating channel 17 is also externally connected to an ammonia inlet pipe 19 for supplying ammonia.

[0053] The exhaust gas and ammonia are guided and evenly distributed by utilizing the matching structure between the heating channel 17 and the ammonia inlet pipe 19, specifically as follows: a heating pipe is arranged inside the heating channel 17, the other end of the ammonia inlet pipe 19 is adjacent to the top of the heating pipe, a plurality of partitions 171 are distributed in an annular manner at the outer end of the heating pipe, the partitions 171 are made of heat-conducting material, and the plurality of partitions 171 divide the interior of the heating channel 17 into heating spaces that are compatible with the number of the plurality of heat-insulating chambers 15, and a plurality of groups of diverter holes 191 connected to the heating spaces are provided at the bottom end of the ammonia inlet pipe 19, so as to realize the injection of ammonia at the top of the heating channel 17;

[0054] In this process, ammonia and the introduced exhaust gas flow together into multiple heating spaces, and the exhaust gas temperature is raised to 300°C-400°C by the heating channel 17. The heated exhaust gas is introduced into multiple insulation chambers 15 by the conducting pipe. It should be added here that multiple guide plates staggered from top to bottom can be added in the heating space to extend the exhaust gas heating path and improve the exhaust gas heating effect.

[0055] After being guided and evenly distributed, the air flows into a plurality of heat-insulating chambers 15, and a plurality of filter chambers 16 serve as carriers to efficiently remove nitrogen oxides and dust from the exhaust gas under the action of ammonia.

[0056] In the exhaust gas insulation treatment process, in order to make full use of the residual heat energy of the clean exhaust gas after treatment, the existing ceramic filter tube structure is improved as follows:

[0057] The insulation chamber 15 is fixed with a plugging plate 18 at both ends thereof for embedding and installing a plurality of filter chambers 16. The filter chamber 16 includes an outer filter sleeve 161 and a ceramic filter tube 162 therein. The outer filter sleeve 161 is located on the end wall under the lower plugging plate 18 and is provided with an air inlet hole connected to the bottom of the insulation chamber 15.

[0058] The top of the insulation chamber 15 is a closed structure, and the upper and lower blocking plates 18 divide the interior of the insulation chamber 15 into an insulation chamber. A plurality of vents 181 are provided on the upper blocking plate 18, and an air outlet 151 for connecting the insulation chamber and the denitration tower 2 is provided on the lower end wall of the insulation chamber 15;

[0059] The exhaust gas after heating treatment is evenly mixed with ammonia, enters the insulation bin through the conducting pipe, and enters the filter chamber 16 through the air inlet, with multiple ceramic filter tubes 162 as carriers. The treated clean exhaust gas overflows from the top of multiple filter chambers 16 and then flows back downward to the insulation cavity in the insulation chamber 15. The insulation chamber 15 is also made of heat-conducting material. Its purpose is to ensure that the treatment temperature of the filter chamber 16 can be controlled between 280-350°C and reduce the temperature difference between the exhaust gas and the filter chamber 16. The clean exhaust gas after heat exchange treatment enters the denitrification tower 2 through multiple air outlets 151 at the bottom of the insulation chamber 15. During the diffusion of the clean exhaust gas from top to top, the overall environment outside the multiple insulation chambers 15 is insulated, and finally moves upward and is discharged through the exhaust pipe 20 installed on the top of the denitrification tower 2. The exhaust pipe 20 is connected to the chimney through an induced draft fan.

[0060] It should be added that a set of pulse cleaning structure is provided at the top of each heat preservation chamber 15. During the cleaning, pulse gas is introduced into the multiple filter chambers 16. The gas can directly refer to the clean exhaust gas discharged from the exhaust pipe 20. The clean exhaust gas has temperature. Compared with the introduced air, the clean exhaust gas with temperature can maintain the heat preservation environment of the filter chamber 16 while cleaning. The cleaned dust falls into the conical ash hopper of the denitrification tower 2 through the bottom of the heat preservation chamber 15.

[0061] When a chamber needs to be cleaned offline, close the air inlet valve on the bottom pipe of the chamber to isolate the chamber and ensure that other chambers are in working condition.

[0062] In conjunction with Example 1 and Example 2, the purification process of the coke oven chimney exhaust gas can be found in Fig.11 , including the following steps:

[0063] S1, desulfurization treatment: The original exhaust gas is sent into the desulfurization tower 1 through the air inlet pipe 3 by the booster fan, and the original exhaust gas is rotated upward along the multiple annular desulfurization chambers of the desulfurization sleeve through the air distribution component 4, and the calcium-based desulfurizer is synchronously sprayed upward at the upper position of the original exhaust gas injection by the distribution component 11;

[0064] The original exhaust gas drives the calcium-based desulfurizer to diffuse upward along the multiple annular desulfurization cavities distributed inside and outside the desulfurization sleeve for a long distance reaction, removing sulfur dioxide and other acidic media. This process generates calcium sulfate.

[0065] S2, dust removal treatment: the reaction waste gas continues to move upward along the desulfurization sleeve and enters the centrifugal channel, where the waste gas is centrifuged by multiple fan flow plates 13 driven by the rotating column 9, and the dust and calcium sulfate precipitate generated by the reaction are thrown to the inner wall of the return hood 12 and fall through the return cavity;

[0066] S3, denitration treatment: the original exhaust gas undergoes a mixed desulfurization reaction in a fluidized state and then passes through the conversion flue 14 into the heating channel 17 installed at the axial position of the denitration tower 2. Ammonia is sprayed into the top of the heating channel 17 to raise the exhaust gas temperature to 300°C-400°C. After diversion and uniform airflow distribution, the exhaust gas enters multiple heat preservation chambers 15. Multiple filter chambers 16 serve as carriers to efficiently remove nitrogen oxides and dust in the exhaust gas under the action of ammonia.

[0067] S4. Exhaust gas insulation treatment: The treated clean exhaust gas overflows from the top of multiple filter chambers 16 and then flows back downward to the insulation chamber 15, ensuring that the treatment temperature of the filter chamber 16 is controlled between 280-350°C. The clean exhaust gas after heat exchange treatment enters the denitrification tower 2 through multiple air outlets 151 at the bottom of the insulation chamber 15 to insulate the overall environment inside the denitrification tower 2, and finally enters the chimney through the exhaust pipe 20.

[0068] In summary: The present invention is based on the operating principle of existing waste gas desulfurization and denitrification. A plurality of annular desulfurization chambers distributed inside and outside are arranged in the desulfurization tower. In the desulfurization and dust removal link, a rotating air distribution component is used to split and spray the incoming original waste gas upward and cooperate with the desulfurizer inlet pipe to simultaneously split and spray the calcium-based desulfurizer upward. The narrow annular desulfurization chamber is equipped with a multi-point high-speed conveying mode. Its purpose is to provide the power for the waste gas to move upward and diffuse, which is beneficial to the full mixing and reaction of the desulfurizer and the waste gas, and effectively avoids the situation where some desulfurizers sink before reacting in time, thereby improving the utilization rate of the desulfurizer, and utilizing the centrifugal channel at the top to separate and fall the dust and calcium sulfate precipitation through the return cavity. In the denitrification and dust removal link, the ceramic filter tube structure is coordinated with the insulation chamber, and the waste gas reflux is utilized for waste heat insulation to provide an efficient denitrification environment.

[0069] The above is only a preferred specific implementation manner of the present invention; but the protection scope of the present invention is not limited thereto; any technician familiar with the technical field within the technical scope disclosed by the present invention; any equivalent replacement or change based on the technical solution and improved concept of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A purification treatment device for exhaust gas from a coke oven chimney, comprising a desulfurization tower (1) and a denitrification tower (2), characterized in that: The desulfurization tower (1) is provided with a desulfurization sleeve inside, and the desulfurization sleeve comprises an outer ring cylinder (5), a middle ring cylinder (6), and an inner ring cylinder (7) which are sequentially sleeved and arranged from the outside to the inside. A rotating column (9) is rotatably installed inside the inner ring cylinder (7) and penetrates the inner ring cylinder from top to bottom. A plurality of annular desulfurization cavities are formed inside the desulfurization sleeve from the outside to the inside. A gas distribution component (4) located at the bottom of the desulfurization sleeve and penetrating and distributed to the plurality of annular desulfurization cavities is fixedly installed at the lower end of the rotating column (9). A material distribution component (11) which is compatible with the gas distribution component (4) and also penetrates the plurality of annular desulfurization cavities is provided at the lower end of the outer ring cylinder (5); The denitration tower (2) is fixedly provided with a heating channel (17) in the middle thereof and a plurality of heat-insulating chambers (15) annularly distributed outside the heating channel (17) via a fixing plate, each heat-insulating chamber (15) having a plurality of filter chambers (16) annularly distributed inside the heat-insulating chamber (15) and extending to the bottom thereof, and the bottom end of the heating channel (17) is respectively connected to the filter chamber (16) of each heat-insulating chamber (15) via a plurality of conducting pipes.

2. The coke oven chimney exhaust gas purification equipment according to claim 1, characterized in that: A reflux hood (12) is installed on the top of the desulfurization tower (1), and the space between the reflux hood (12) and the top of the desulfurization sleeve forms a centrifugal channel. The end wall of the rotating column (9) located in the centrifugal channel is provided with a plurality of fan plates (13) distributed in an annular manner, and a return cavity connected to the centrifugal channel is formed between the outer ring cylinder (5) and the inner wall of the desulfurization tower (1).

3. The coke oven chimney exhaust gas purification equipment according to claim 2, characterized in that: The air distribution assembly (4) comprises a rotating disk (41) which is coaxially arranged with the rotating column (9) and has a return material gap reserved between the rotating disk and the bottom of the desulfurization sleeve. The bottom end of the rotating disk (41) is provided with a plurality of ventilation pipes (42) which are connected to each other and are inner and outer connected. The ventilation pipes (42) are annularly fixedly mounted with a plurality of injection pipes (43) which penetrate the rotating disk (41) and extend to the bottom of the annular desulfurization chamber.

4. The coke oven chimney exhaust gas purification equipment according to claim 3, characterized in that: A plurality of fan flow plates (44) corresponding to the positions of the plurality of annular desulfurization chambers are annularly distributed from the inside to the outside at the upper end of the rotating disk (41), and the fan flow plates (44) are adjacent to the injection pipe (43) and are arranged to tilt backwards.

5. The coke oven chimney exhaust gas purification equipment according to claim 4, characterized in that: The material distribution assembly (11) comprises an annular tube located outside the bottom of the outer ring tube (5), on which are distributed a plurality of material distribution pipes which are staggered and extend obliquely upward to a plurality of annular desulfurization chambers respectively, the material distribution pipe being located above the injection pipe (43), and one end of the annular tube being externally connected to a desulfurization agent inlet pipe (10).

6. The coke oven chimney exhaust gas purification equipment according to claim 1, characterized in that: The upper and lower ends of the heat-insulating chamber (15) are fixed with blocking plates (18) for embedding and installing the filter chamber (16); the filter chamber (16) comprises an outer filter sleeve (161) and a ceramic filter tube (162) therein; the lower end wall of the outer filter sleeve (161) is provided with an air inlet hole connected to the bottom of the heat-insulating chamber (15).

7. The coke oven chimney exhaust gas purification equipment according to claim 6, characterized in that: The top of the heat-insulating chamber (15) is a closed structure, and the interior of the heat-insulating chamber (15) is divided into a heat-insulating chamber by upper and lower sealing plates (18). A plurality of vents (181) are provided on the upper sealing plate (18), and an air outlet (151) for connecting the heat-insulating chamber and the denitration tower (2) is provided on the lower end wall of the heat-insulating chamber (15).

8. A process for purifying exhaust gas from a coke oven chimney, using the purifying exhaust gas from a coke oven chimney equipment as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1, desulfurization treatment: the original exhaust gas is rotated and distributed upward along the multiple annular desulfurization chambers of the desulfurization sleeve through the booster fan and the air distribution component (4), and the calcium-based desulfurizer is synchronously split and sprayed upward at the upper position of the original exhaust gas injection by the distribution component (11). The original exhaust gas drives the calcium-based desulfurizer to diffuse and react upward along the multiple annular desulfurization chambers over a long distance, thereby removing sulfur dioxide and other acidic media. Calcium sulfate is generated in this process; S2. Dust removal: The waste gas is passed upward into the centrifugal channel, and the dust and calcium sulfate precipitate generated by the reaction fall through the return cavity; S3, denitrification and dust removal treatment: After the exhaust gas undergoes a desulfurization reaction in a fluidized state, it is passed into a heating channel (17) for heating, and ammonia is simultaneously sprayed into the top of the heating channel (17). After the two are evenly distributed by air flow, multiple filter chambers (16) are used as carriers to efficiently remove nitrogen oxides and dust in the exhaust gas; S4. Exhaust gas external discharge insulation treatment: Before being discharged, the clean exhaust gas overflows from the top of the multiple filter chambers (16) and then flows back downward to the insulation chamber (15) for insulation treatment.

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