Purification and treatment equipment and process for coke oven chimney waste gas

Abstract

The present invention discloses a purification treatment device and process for coke oven chimney waste gas, belonging to the technical field of waste gas treatment. Based on the existing operating principle of waste gas desulfurization and denitrification, a desulfurization tower is provided with multiple annular desulfurization cavities distributed inside and outside. In the desulfurization and dust removal process, a rotating gas distribution component is used to spray the incoming raw waste gas upward in a split flow manner and cooperate with the desulfurizing agent inlet pipe to synchronously spray the calcium-based desulfurizing agent upward in a split flow manner. The narrow annular desulfurization cavity is equipped with a multi-point high-speed conveying mode, aiming to provide the power for the upward movement and diffusion of the waste gas, which is beneficial to the full mixing of the desulfurizing agent and the waste gas for reaction, and effectively avoids the situation that some desulfurizing agents sink without reacting in time, improving the utilization rate of the desulfurizing agent. The centrifugal channel at the top is used to realize the separation and fall of dust and calcium sulfate precipitation through the falling cavity. In the denitrification and dust removal process, the ceramic filter tube structure is combined with the heat preservation chamber, and the waste gas reflux is used for heat preservation with waste heat to provide a high-efficiency denitrification 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 the waste gas of a coke oven chimney. Background Art

[0002] A coke oven is a kiln for refining coke from coal. During operation, a large amount of waste gas is generated. In particular, for existing coke oven waste gas, desulfurization waste liquid medium is introduced into the coke oven waste gas and burned together, resulting in a significant increase in the waste gas volume and a doubling of the pollutant concentration. It is necessary to carry out desulfurization treatment before discharging. For the treatment of coke oven waste gas, the traditional coke oven waste gas treatment system adopts the process of "dry desulfurization + dust removal + denitration" to achieve the reduction of waste gas pollutants. The relevant processes can refer to the content with the publication number CN219942346U and the publication number CN115715927A.

[0003] In the prior art for the waste gas desulfurization and dust removal link, most of them directly introduce the desulfurizer 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 widely in all directions due to the pressure reduction. Due to the large volume inside the tower body, it affects the full contact and mixing of the desulfurizer and the waste gas, causing some calcium-based desulfurizer to sink without reacting in time, resulting in low desulfurization efficiency. When the pressure of the waste gas discharged upward is insufficient, the calcium sulfate precipitate generated 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 denitration treatment after waste gas desulfurization, the existing method directly introduces high-temperature flue gas and uses a catalytic ceramic filter tube as a carrier for denitration treatment, and the waste gas is directly discharged 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 gas waste heat is not utilized.

[0005] Therefore, in view of the above problems, we propose a purification treatment device and process for the waste gas of a coke oven chimney. Summary of the Invention

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

[0007] The object of the present invention can be achieved by the following technical solutions: a purification treatment device for coke oven chimney waste gas, including a desulfurization tower and a denitration tower. A desulfurization sleeve is arranged inside the desulfurization tower. The desulfurization sleeve includes an outer ring cylinder, a middle ring cylinder, and an inner ring cylinder that are sleeved and distributed in sequence from outside to inside. A rotating column passing through its upper and lower parts is rotatably installed inside the inner ring cylinder. Multiple annular desulfurization chambers are formed in the desulfurization sleeve and distributed from outside to inside. A gas distribution component located at the bottom of the desulfurization sleeve and passing through to multiple annular desulfurization chambers is fixedly installed at the lower end of the rotating column. A cloth distribution component that is adapted to the gas distribution component and also passes through to multiple annular desulfurization chambers is arranged at the lower end of the outer ring cylinder. The cloth distribution component is located above the gas distribution component;

[0008] Inside the denitration tower, a heating channel located in the middle and multiple heat preservation chambers annularly distributed outside the heating channel are fixedly installed through a fixing plate. Multiple filtering chambers passing through to the bottom are annularly distributed in each heat preservation chamber. The bottom end of the heating channel is respectively communicated with the filtering chambers of each heat preservation chamber through multiple conduction pipes.

[0009] Further, a reflux cover is installed at the top of the desulfurization tower. The space between the reflux cover and the top end of the desulfurization sleeve forms a centrifugal channel. Multiple fan-shaped flow plates are annularly distributed on the end wall of the rotating column located in the centrifugal channel. A falling cavity communicated with the centrifugal channel is formed between the outer ring cylinder and the inner wall of the desulfurization tower.

[0010] Further, the gas distribution component includes a rotating disk coaxially arranged with the rotating column and having a return material gap reserved between the rotating disk and the bottom of the desulfurization sleeve. Multiple internally and externally sleeved and interconnected air pipes are arranged at the bottom end of the rotating disk. Multiple injection pipes passing through the rotating disk and extending to the bottom of the annular desulfurization chamber are annularly and fixedly installed on the air pipes.

[0011] Further, multiple fan-shaped flow pieces corresponding to the positions of multiple annular desulfurization chambers are annularly distributed on the upper end of the rotating disk from inside to outside. The fan-shaped flow pieces are close to the injection pipes and are inclined backward.

[0012] Further, the cloth distribution component includes an annular pipe located outside the bottom of the outer ring cylinder. Multiple cloth distribution pipes are distributed on the annular pipe and are staggered and inclined upward to extend to multiple annular desulfurization chambers respectively. The cloth distribution pipes are located above the injection pipes. One end of the annular pipe is externally connected with a desulfurizing agent inlet pipe.

[0013] Further, plugging plates for embedding and installing the filtering chambers are fixed at both the upper and lower ends of the heat preservation chamber. The filtering chamber includes an outer filter sleeve and a ceramic filter pipe inside it. An air inlet hole communicated with the bottom of the heat preservation chamber is opened on the lower end wall of the outer filter sleeve.

[0014] Further, the top end of the heat preservation chamber is a closed structure. The upper and lower two plugging plates divide the inner part of the heat preservation chamber into a heat preservation cavity. Multiple air vents are opened on the plugging plate located above. And an air outlet for communicating the heat preservation cavity and the denitration tower is opened on the lower end wall of the heat preservation chamber.

[0015] Purification treatment process for coke oven chimney waste gas, comprising the following steps:

[0016] S1. Desulfurization treatment: The original waste gas is rotated and distributed upward along multiple annular desulfurization chambers of the desulfurization sleeve through a booster fan and a gas distribution component, and a calcium-based desulfurizing agent is synchronously sprayed upward in a split flow above the position where the original waste gas is sprayed by using a cloth component. The original waste gas drives the calcium-based desulfurizing agent to diffuse and react upward along multiple annular desulfurization chambers for a long distance, removing sulfur dioxide and other acidic media, and calcium sulfate is generated in this process;

[0017] S2. Dust removal treatment: The waste gas is introduced upward into a centrifugal channel, and dust and the precipitated calcium sulfate generated by the reaction fall through a falling chamber;

[0018] S3. Denitrification-dust removal treatment: After the waste gas undergoes a desulfurization reaction in a fluidized state for the first time, it is introduced into a heating channel for temperature rise, and ammonia gas is sprayed into the top of the heating channel synchronously. After the two are evenly distributed by the air flow, multiple filter chambers are used as carriers to efficiently remove nitrogen oxides and dust in the waste gas;

[0019] S4. Heat preservation treatment for waste gas discharge: The clean waste gas overflows from the top of multiple filter chambers before being discharged and then flows downward and returns to the heat preservation chamber for heat preservation treatment.

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

[0021] 1. 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 the desulfurizing agent and the waste gas, by arranging multiple annular desulfurization chambers with inner and outer sleeves in the desulfurization tower, in the desulfurization and dust removal link, the incoming original waste gas is split and sprayed upward by a rotating gas distribution component and is matched with the desulfurizing agent inlet pipe to synchronously split and spray the calcium-based desulfurizing agent upward. The narrow annular desulfurization chamber is equipped with a multi-point high-speed conveying mode, aiming to provide power for the upward movement and diffusion of the waste gas, which is beneficial to the full mixing and reaction of the desulfurizing agent and the waste gas, and effectively avoids the situation that some desulfurizing agents sink without timely reaction, improves the utilization rate of the desulfurizing agent, and uses the centrifugal channel at the top to cooperate with the falling chamber to realize the separation of calcium sulfate precipitation and the waste gas;

[0022] 2. A heating system and a heat preservation system are added in the denitrification tower. The waste gas after the first fluidized desulfurization is mixed with ammonia gas for temperature rise, and after being guided and evenly distributed by the air flow, it enters a multi-chamber ceramic filter tube structure, effectively improving the denitrification and dust removal effect. In addition, the existing ceramic filter tube structure is improved. The clean waste gas overflows from the top of multiple filter chambers and then flows downward and returns to the heat preservation chamber for heat preservation, reducing the temperature difference between the waste gas and the filter chambers. The heat-exchanged clean waste gas 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 waste gas waste heat utilization effect, thus ensuring a good denitrification treatment environment and enhancing the denitrification and dust removal effect. Description of the Drawings

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

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

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

[0026] Figure 4 It is a bottom view of the desulfurization sleeve of the present invention;

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

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

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

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

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

[0032] Figure 10 It is a cross-sectional view of the joint of the heat preservation chamber and the filtration chamber of the present invention;

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

[0034] Description of the reference numerals in the drawings:

[0035] 1. Desulfurization tower; 2. Denitration tower; 3. Inlet pipe; 301. Shunt branch pipe; 4. Air distribution component; 41. Rotating disk; 42. Vent pipe; 43. Injection pipe; 44. Fan flow piece; 5. Outer ring cylinder; 6. Middle ring cylinder; 7. Inner ring cylinder; 8. Flow guide cover; 9. Rotating column; 10. Desulfurizing agent inlet pipe; 11. Cloth distribution component; 12. Return flow cover; 13. Fan flow plate; 14. Conversion flue; 15. Heat preservation chamber; 151. Air outlet; 16. Filtration chamber; 161. Outer filter sleeve; 161. Ceramic filter tube; 17. Heating channel; 171. Partition piece; 18. Sealing plate; 181. Vent hole; 19. Ammonia inlet pipe; 191. Shunt hole; 20. Waste gas discharge pipe. Detailed Description of the Invention

[0036] The following will describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] Embodiment 1: Aiming at the problem of low desulfurization efficiency caused by insufficient reaction between the desulfurizer and the waste gas in the prior art, the desulfurization equipment is optimized and improved, and the following technical solutions are proposed:

[0038] Please refer to Figure 1 , the present invention discloses a purification treatment device for coke oven chimney waste gas. Please refer to Figure 1 , Figure 4 , including a desulfurization tower 1 and a denitration tower 2. Conical ash hoppers are provided at the bottoms of the desulfurization tower 1 and the denitration tower 2. A desulfurization sleeve is arranged inside the desulfurization tower 1. The desulfurization sleeve includes an outer ring cylinder 5, a middle ring cylinder 6, and an inner ring cylinder 7 that are sleeved and distributed in sequence from outside to inside. A rotating column 9 that penetrates up and down is rotatably installed inside the inner ring cylinder 7. A plurality of annular desulfurization chambers are formed in the desulfurization sleeve and are distributed from outside to inside. Moreover, the middle ring cylinder 6, the inner ring cylinder 7, and the flow guide cover 8 are fixedly installed on the inner wall of the desulfurization tower 1 through partitions on both sides, so that the outer ring cylinder 5, the middle ring cylinder 6, and the inner ring cylinder 7 are in a fixed installation state, facilitating the full mixing of the original waste gas in the annular desulfurization chambers with a smaller gap and the calcium-based desulfurizer powder sprayed upward;

[0039] Please refer to Figure 3 , a gas distribution assembly 4 is fixedly installed at the lower end of the rotating column 9 and is located at the bottom of the desulfurization sleeve and penetrates into a plurality of annular desulfurization chambers. A cloth distribution assembly 11 that is adapted to the gas distribution assembly 4 and also penetrates into a plurality of annular desulfurization chambers is provided at the lower end of the outer ring cylinder 5. The cloth distribution assembly 11 is located above the gas distribution assembly 4. A bearing tray is fixed at the conical ash hopper at the bottom end of the desulfurization tower 1 through a plurality of strengthening rods. The gas distribution assembly 4 is rotatably installed on the bearing tray through a connecting pipe. The inner end of the air inlet pipe 3 is connected and installed to the connecting pipe through a rotary joint, realizing that the gas distribution assembly 4 does not affect continuous gas supply during rotation;

[0040] Among them, please refer to Figure 6 , the gas distribution assembly 4 includes a rotating disk 41 that 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. A plurality of internally and externally sleeved and interconnected air pipes 42 are provided at the bottom end of the rotating disk 41. A plurality of injection pipes 43 that penetrate through the rotating disk 41 and extend to the bottom of the annular desulfurization chamber are annularly and fixedly installed on the air pipes 42. A plurality of fan-shaped flow vanes 44 corresponding to the positions of a plurality of annular desulfurization chambers are annularly distributed from inside to outside at the upper end of the rotating disk 41. The fan-shaped flow vanes 44 are adjacent to the injection pipes 43 and are inclined backward;

[0041] Please refer toFigure 3 , Figure 4 and Figure 7 , the cloth component 11 includes an annular pipe located on the outer side of the bottom of the outer ring cylinder 5. A plurality of cloth pipes are distributed on the annular pipe, which are arranged in a staggered manner and extend obliquely upward to a plurality of annular desulfurization cavities respectively. The cloth pipes are located above the injection pipes 43. One end of the annular pipe is externally connected to a desulfurizing agent inlet pipe 10. The cloth pipes are annularly distributed, and their inner and outer lengths are adapted to the annular desulfurization cavities distributed inside and outside, that is, the cloth pipes corresponding to the outermost annular desulfurization cavity are the shortest, and gradually increase from the outside to the inside. The cloth pipes distributed inside and outside are arranged in a staggered manner, and the number of cloth pipes from the outside to the inside decreases in turn. One end of the annular pipe is externally connected to a desulfurizing agent inlet pipe 10, and the other end of the desulfurizing agent inlet pipe 10 is also connected to a calcium-based desulfurizing agent supply source through a booster fan.

[0042] Please refer to Figure 3 , the intake pipe 3 located outside the desulfurization tower 1 is fixedly connected to the ventilation pipe 42. A booster fan is externally connected to the intake pipe 3, and the booster fan is connected to the coke oven flue through a pipeline. A plurality of injection pipes 43 distributed in a layer-by-layer annular manner extend to the bottoms of a plurality of annular desulfurization cavities from the outside to the inside respectively;

[0043] The intake pipe 3 is connected to one end of the desulfurizing agent inlet pipe 10 through a shunt branch pipe 301. Taking part of the original waste gas as the conveying medium, part of the waste gas has a certain carrying and conveying capacity, so as to realize the uniform distribution and conveyance of the calcium-based desulfurizing agent to a plurality of annular desulfurization cavities through a plurality of cloth pipes. The plurality of cloth pipes are arranged obliquely upward, have upward power, and can smoothly diffuse upward along the annular desulfurization cavity under the continuous push of the waste gas below. The desulfurizing agent is thermally activated in the annular desulfurization cavity, and the specific surface area increases rapidly, and physical and chemical reactions occur with acidic substances such as sulfur dioxide in the waste gas, so that acidic substances such as sulfur dioxide in the waste gas are absorbed and purified, and sulfur dioxide and other acidic media are removed.

[0044] For the desulfurization reaction process, the internal space of the traditional straight-through desulfurization tower is divided into a plurality of annular desulfurization cavities that are separated inside and outside and have a narrow spacing, which is beneficial to the shunt of the original waste gas and the calcium-based desulfurizing agent led upward. On the one hand, it is beneficial for the desulfurizing agent to be fully mixed with the waste gas for reaction. On the other hand, the narrow annular desulfurization cavity is equipped with the continuously upwardly conveyed waste gas and calcium-based desulfurizing agent. The purpose is to make the waste gas have the power to move and diffuse upward, effectively avoiding the situation that some calcium-based desulfurizing agents sink before reacting in time, and improving the utilization rate of the desulfurizing agent;

[0045] In addition, please refer to Figure 4 and Figure 5, a plurality of annularly distributed fan-shaped flow plates 44 are added to the rotating disk 41, and each fan-shaped flow plate 44 is arranged obliquely backward adjacent to the injection pipe 43. When the air distribution assembly 4 rotates counterclockwise with the rotating column 9, the rotation direction of the rotating disk 41 is set opposite to the inclination direction of the injection pipe 43. After the original waste gas is rotationally injected through the injection pipe 43, the waste gas is evenly diffused in the annular desulfurization chamber and moves upward. The fan-shaped flow plates 44 rotating behind each injection pipe 43 are conducive to guiding and diffusing the overflowing original waste gas upward. The plurality of fan-shaped flow plates 44 in circular rotational motion provide a centrifugal swirling force for the waste gas to move further upward, which is conducive to the full and uniform diffusion of the original waste gas in the entire annular desulfurization chamber, further improving the desulfurization reaction effect.

[0046] Please refer to Figure 3 、 Figure 5 , a conical flow guide cover 8 with a wider top and a narrower bottom is fixedly installed at the top of the outer ring cylinder 5. A return cover 12 is installed at the top of the desulfurization tower 1. The space between the return cover 12 and the top of the desulfurization sleeve forms a centrifugal channel. A plurality of fan-shaped plates 13 are annularly distributed on the end wall of the rotating column 9 located in the centrifugal channel. The return cover 12 is fixedly installed at the top of the desulfurization tower 1 and has a narrower top and a wider bottom and is in a conical structure. A driving motor for rotating the rotating column 9 is fixed at the top of the desulfurization tower 1;

[0047] The setting of the flow guide cover 8 is conducive to guiding the waste gas in the plurality of 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 flow guide cover 8 intercepts the calcium-based desulfurizer particles that have not reacted in time and part of the calcium sulfate precipitate generated by the reaction, so that the calcium-based desulfurizer particles that have not reacted in time and part of the calcium sulfate precipitate generated by the reaction flow back to the annular desulfurization chamber under the action of the inclined surface in the flow guide cover 8. In this process, it is conducive to the continuous reaction of the calcium-based desulfurizer particles that have not reacted in time, and the part of the calcium sulfate precipitate that falls is dropped through the return material gap formed between the rotating disk 41 and the bottom of the desulfurization sleeve.

[0048] The waste gas carrying most of the calcium sulfate precipitate enters the centrifugal channel through the flow guide cover 8. Under the action of the centrifugal motion of the plurality of fan-shaped plates 13, the waste gas is thrown out toward the inner wall of the return cover 12. It should be added here that a conical sleeve is fixed on the rotating column 9 above the flow guide cover 8. The conical sleeve has a wider top and a narrower bottom. The plurality of fan-shaped plates 13 are annularly distributed on the conical sleeve, and the fan-shaped plates 13 are obliquely arranged on the conical sleeve, and their inclination direction is opposite to the inclination direction of the fan-shaped flow plates 44. The fan-shaped plates 13 are arranged from bottom to top along the counterclockwise rotation direction. When the fan-shaped plates 13 rotate counterclockwise with the rotating column 9, the lower side of the fan-shaped plates 13 directly contacts the rising waste gas and centrifugally throws the waste gas outward, improving the solid-gas separation effect and enhancing the purification ability of the desulfurization tower.

[0049] A return cavity communicating with 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 towards the inner wall of the return hood 12 and fall through the return cavity, and finally 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 denitration tower 2 through the conversion flue 14 installed at the top.

[0050] Embodiment 2: In this embodiment, the following optimization improvements are made to the existing denitration-dust removal structure:

[0051] Please refer to Figure 2 and Figures 8 - 10 Inside the denitration tower 2, a heating channel 17 located in the middle and a plurality of heat preservation chambers 15 annularly distributed outside the heating channel 17 are fixedly installed through fixing plates. A plurality of filter chambers 16 penetrating to the bottom are annularly distributed in each heat preservation chamber 15. The bottom end of the heating channel 17 is respectively connected to the filter chambers 16 of each heat preservation chamber 15 through a plurality of conduction pipes.

[0052] The heat preservation chamber 15 has an upper-wide and lower-narrow conical cylinder structure. The top end of the heating channel 17 is connected to the conversion flue 14, and an ammonia inlet pipe 19 for supplying ammonia is also externally connected to the top end of the heating channel 17;

[0053] Using the cooperation structure between the heating channel 17 and the ammonia inlet pipe 19 to divert and evenly distribute the exhaust gas and ammonia, specifically as follows: A heating pipe is provided inside the heating channel 17. The other end of the ammonia inlet pipe 19 is adjacent to the top end of the heating pipe. A plurality of partition plates 171 are annularly distributed at the outer end of the heating pipe. The partition plates 171 are made of heat-conducting materials. The plurality of partition plates 171 divide the interior of the heating channel 17 into heating spaces adapted to the number of the plurality of heat preservation chambers 15. A plurality of groups of shunt holes 191 communicating with the heating spaces are opened at the bottom end of the ammonia inlet pipe 19 to realize spraying ammonia at the top of the heating channel 17;

[0054] In this process, ammonia and the introduced exhaust gas are evenly flowed into the plurality of heating spaces together. The heating channel 17 is used to raise the temperature of the exhaust gas to 300°C - 400°C, and the heated exhaust gas is introduced into the plurality of heat preservation chambers 15 through the conduction pipes. Here, it should be added that a plurality of diversion 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 diversion and air flow distribution, it enters the plurality of heat preservation chambers 15. With the plurality of filter chambers 16 as carriers, nitrogen oxides and dust in the exhaust gas are efficiently removed under the action of ammonia.

[0056] In the exhaust gas discharge heat preservation treatment link, in order to make full use of the waste heat energy of the treated clean exhaust gas, the existing ceramic filter tube structure is improved, specifically as follows:

[0057] Sealing plates 18 for embedding and installing a plurality of filter chambers 16 are fixedly arranged at both the upper and lower ends of the heat preservation chamber 15. The filter chamber 16 includes an outer filter sleeve 161 and a ceramic filter tube 162 inside it. An air inlet hole communicating with the bottom of the heat preservation chamber 15 is provided on the end wall of the outer filter sleeve 161 located below the lower sealing plate 18.

[0058] The top end of the heat preservation chamber 15 is a closed structure. The upper and lower two sealing plates 18 divide the interior of the heat preservation chamber 15 into a heat preservation cavity. A plurality of ventilation openings 181 are provided on the upper sealing plate 18, and an air outlet 151 for communicating the heat preservation cavity and the denitration tower 2 is provided on the lower end wall of the heat preservation chamber 15.

[0059] The heated waste gas is mixed evenly with ammonia, enters the heat preservation chamber through the conduction pipe, and is introduced into the filter chamber 16 through the air inlet hole. With a plurality of ceramic filter tubes 162 as carriers, the treated clean waste gas overflows from the top of the plurality of filter chambers 16 and then flows downward and back into the heat preservation cavity in the heat preservation chamber 15. The heat preservation chamber 15 is also made of a heat-conducting material. The purpose is to ensure that the treatment temperature of the filter chamber 16 can be controlled between 280 - 350 °C, reduce the temperature difference between the waste gas and the filter chamber 16. The treated clean waste gas enters the denitration tower 2 through a plurality of air outlet holes 151 at the bottom of the heat preservation chamber 15. During the diffusion process of the clean waste gas from top to bottom, it insulates the overall environment outside the plurality of heat preservation chambers 15, and finally moves upward and is discharged through the waste gas discharge pipe 20 installed at the top of the denitration tower 2. The waste gas discharge pipe 20 is connected to the chimney through an induced draft fan.

[0060] It should be added here that a set of pulse dust cleaning structure is provided at the top end of each heat preservation chamber 15. During dust cleaning, pulse gas is introduced into the interior of the plurality of filter chambers 16. This gas can directly use the clean waste gas discharged from the waste gas discharge pipe 20. The clean waste gas has a temperature. Compared with introducing air, the clean waste gas with temperature can maintain the heat preservation environment of the filter chamber 16 while cleaning the dust. The dust cleaned down falls into the conical ash hopper of the denitration tower 2 through the bottom of the heat preservation chamber 15.

[0061] When a chamber needs to be offline for dust cleaning, close the intake valve on the conduction pipe at the bottom of this chamber to isolate this chamber and ensure that other chambers are in a working state.

[0062] Combined with Embodiment 1 and Embodiment 2, for the purification treatment process of coke oven chimney waste gas, please refer to Figure 11 , including the following steps:

[0063] S1. Desulfurization treatment: The original waste gas is sent into the desulfurization tower 1 through the booster fan from the intake pipe 3. The original waste gas is distributed in a swirling manner upward along a plurality of annular desulfurization cavities of the desulfurization sleeve through the air distribution component 4, and the calcium-based desulfurizing agent is simultaneously sprayed upward in a split manner at a position above the injection of the original waste gas by the cloth distribution component 11.

[0064] The original waste gas drives the calcium-based desulfurizer to diffuse and react upward over a long distance along multiple annular desulfurization chambers distributed inside and outside the desulfurization sleeve, removing sulfur dioxide and other acidic media, and calcium sulfate is generated in this process.

[0065] S2. Dust removal treatment: The reacted waste gas continuously moves upward along the desulfurization sleeve and enters the centrifugal channel. Here, multiple fan-shaped flow plates 13 driven by the rotating column 9 centrifuge the waste gas, and the dust and the precipitated calcium sulfate generated by the reaction are thrown towards the inner wall of the return hood 12 and fall through the return cavity.

[0066] S3. Denitration treatment: After the original waste gas undergoes a mixed desulfurization reaction in a fluidized state for the first time, it enters the heating channel 17 installed at the axial center of the denitration tower 2 through the conversion flue 14. Ammonia is sprayed at the top of the heating channel 17 to raise the temperature of the waste gas to 300°C - 400°C. After diversion and uniform air distribution, it enters multiple heat preservation chambers 15. With multiple filter chambers 16 as carriers, nitrogen oxides and dust in the waste gas are efficiently removed under the action of ammonia.

[0067] S4. Heat preservation treatment for waste gas discharge: The treated clean waste gas overflows from the top of multiple filter chambers 16 and then flows downward and back into the heat preservation chambers 15 to ensure that the treatment temperature of the filter chambers 16 is controlled between 280 - 350°C. The clean waste gas after heat exchange treatment enters the denitration tower 2 through multiple air outlets 151 at the bottom of the heat preservation chambers 15 to keep the overall environment inside the denitration tower 2 warm, and finally enters the chimney through the gas discharge pipe 20.

[0068] In summary: Based on the existing operating principle of waste gas desulfurization and denitration, this invention sets multiple annular desulfurization chambers distributed inside and outside in the desulfurization tower. In the desulfurization and dust removal link, the distributed gas component that rotates operates to shunt and spray the incoming original waste gas upward and cooperates with the desulfurizer inlet pipe to synchronously shunt and spray the calcium-based desulfurizer upward. The narrow annular desulfurization chambers are equipped with a multi-point high-speed transportation mode, aiming to provide the power for the upward movement and diffusion of the waste gas, which is not only conducive to the full mixing of the desulfurizer and the waste gas for reaction, but also effectively avoids the situation where some desulfurizer sinks without reacting in time, improves the utilization rate of the desulfurizer, and uses the centrifugal channel at the top to realize the separation and fall of dust and calcium sulfate precipitation through the return cavity. In the denitration and dust removal link, the ceramic filter tube structure is combined with the heat preservation chambers, and the waste gas reflux is used to keep warm with the waste heat to provide an efficient denitration environment.

[0069] The above; only the preferred specific implementation manners of the present invention; but the protection scope of the present invention is not limited thereto; any person skilled in the art within the technical scope disclosed by the present invention; according to the technical solutions of the present invention and their improved concepts, making equivalent substitutions or changes; should 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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