Arsenic flue gas high-temperature filtering and purifying device

Abstract

The invention discloses an arsenic flue gas high-temperature filtering and purifying device, and relates to the technical field of arsenic flue gas purification, the arsenic flue gas high-temperature filtering and purifying device comprises a gas inlet system, a pretreatment system, a high-temperature filtering system, a purifying system, a condensing system and a tail gas treatment system which are sequentially connected according to a gas treatment flow, a gas outlet of the gas storage bag is connected with a plurality of blowing pipes which are positioned right above the pulse bag-type dust collector. The temperature interval is accurately set in the high-temperature filtering system, the optimal filtering temperature interval is determined, T is larger than or equal to 350 DEG C to 460 DEG C, it is ensured that arsenic flue gas is treated in the optimal filtering temperature interval, in the high-temperature environment, condensation and deposition of arsenic compounds in the filtering process can be effectively avoided, the filtering efficiency and the purification effect are improved, the arsenic filtering rate is larger than or equal to 99.95%, and the arsenic removal rate is larger than or equal to 99%. The stability and the high efficiency of the whole treatment process are ensured, so that impurities and target substances in the arsenic flue gas are separated more accurately.

Description

Technical Field

[0001] This invention relates to the field of arsenic flue gas purification technology, specifically to a high-temperature filtration and purification device for arsenic flue gas. Background Technology

[0002] In tin smelting, arsenic is mainly found in minerals such as arsenopyrite and arsenic pyrrhotite. During the volatilization treatment of tin slag in a fumigation furnace, arsenic volatilizes along with tin into the flue gas, forming arsenic-containing tin dust. Arsenic and its compounds (such as arsenic trioxide) are highly toxic. If not effectively recovered during treatment, arsenic released into the environment will cause serious pollution to soil and water sources. The arsenic in these polluted soils and water sources will accumulate through the food chain, ultimately threatening human health. At the same time, arsenic is an important strategic resource with wide applications in semiconductors, pesticides, and many other fields. Direct emission of arsenic from arsenic-containing flue gas during tin smelting would undoubtedly result in the loss of valuable resources, hindering the rational utilization of resources and sustainable development.

[0003] Currently, the treatment of arsenic-containing flue gas mostly adopts the traditional low-temperature filtration process, which involves cooling the flue gas to below 200°C before filtration and purification. Although this process can separate impurities in the flue gas to a certain extent, the low-temperature environment easily causes arsenic compounds (such as As2O3) to condense prematurely and adhere to the surface of the filter material to form a hard shell. This not only clogs the filter pores and reduces the filtration efficiency, but also increases the difficulty of cleaning, leading to a sharp increase in equipment operating resistance and requiring frequent shutdowns for maintenance.

[0004] However, existing equipment suffers from several drawbacks. First, the low-temperature filtration process, with temperatures controlled below 200°C, may not provide sufficient energy for the pyrolysis reaction, leading to incomplete pyrolysis, poor separation of target substances from impurities, and consequently affecting arsenic recovery and product purity. Arsenic recovery rates are generally below 85%, and the final product purity can only reach around 95%. Second, the filter materials lack sufficient temperature resistance. Traditional filter media (such as ordinary polyester filter cloth) are prone to aging and damage in high-temperature flue gas environments and cannot meet the long-term operating requirements above 300°C, resulting in short equipment lifespan and high maintenance costs. Third, it is difficult to effectively remove the hard dust layer adhering to the filter media, and the unremoved dust further increases the filtration resistance, affecting the normal operation of the equipment.

[0005] Therefore, it is necessary to invent a high-temperature filtration and purification device for arsenic flue gas to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to provide a high-temperature filtration and purification device for arsenic flue gas, so as to solve the problems of insufficient arsenic recovery rate and product purity, easy damage to filter materials, and inconvenience in cleaning and easy clogging of filter media in the existing technology.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-temperature filtration and purification device for arsenic flue gas, comprising an inlet system, a pretreatment system, a high-temperature filtration system, a purification system, a condensation system, and a tail gas treatment system connected sequentially according to a gas processing flow. The pretreatment system is equipped with a cyclone pre-separator and a shell-and-tube heat exchanger. The high-temperature filtration system is equipped with an electric heater and a pulse bag filter. The inlet end of the electric heater is connected to the outlet end of the shell-and-tube heat exchanger, and the outlet end of the electric heater is connected to the pulse bag filter. The pulse bag filter includes stainless steel fiber felt filter elements, which are evenly distributed in an array inside the pulse bag filter housing. An air storage tank is provided outside the pulse bag filter, and the outlet of the air storage tank is connected to multiple blowpipes located directly above the pulse bag filter.

[0008] Preferably, the outlet end of the cyclone pre-separator is connected to the inlet end of the shell-and-tube heat exchanger by a flange seal, and the shell-and-tube heat exchanger is provided with a spiral guide plate inside.

[0009] Preferably, the bottom of the cyclone pre-separator is provided with a conical ash discharge hopper, and a pneumatic slide valve is installed on the ash discharge hopper.

[0010] Preferably, the blow pipe is equipped with a pulse valve, and the pulse valve is electromagnetically controlled. The bottom end of the blow pipe is provided with a blow nozzle at the position corresponding to the stainless steel fiber felt filter element, and the outlet of the blow nozzle has a tapered structure.

[0011] Preferably, the bottom of the stainless steel fiber felt filter element is provided with a conical ash hopper, and the ash discharge pipe of the conical ash hopper is provided with an ash discharge valve.

[0012] Preferably, the purification system is equipped with a gradient sublimation furnace, which has three internal zones: a low-temperature zone, a medium-temperature zone, and a high-temperature zone. The air inlet of the low-temperature zone is connected to the air outlet of the pulse bag filter. The low-temperature zone has a temperature of 350°C-400°C, the medium-temperature zone has a temperature of 400°C-460°C, and the high-temperature zone has a temperature of 460°C-550°C.

[0013] Preferably, the condensation system includes a primary condenser, a secondary condenser, and a tertiary condenser. The inlet of the primary condenser is connected to the outlet of the medium-temperature zone, the outlet of the primary condenser is connected to the inlet of the secondary condenser, and the outlet of the secondary condenser is connected to the inlet of the tertiary condenser.

[0014] Preferably, the condensation system further includes a feed pipe and a switching valve, wherein the feed pipe is located at the bottom of the primary condensation tower, the secondary condensation tower and the tertiary condensation tower, and the switching valve is located on the feed pipe.

[0015] Preferably, the exhaust gas treatment system includes a spray absorption tower and an activated carbon adsorption box, wherein the inlet end of the spray absorption tower is connected to the outlet end of the three-stage condenser tower.

[0016] Preferably, the outlet of the spray absorption tower is connected to the inlet of the activated carbon adsorption box, and the outlet of the activated carbon adsorption box is connected to a chimney.

[0017] The technical effects and advantages provided by the present invention in the above technical solution are as follows: 1. This invention precisely sets the temperature range in the high-temperature filtration system to determine the optimal filtration temperature range, T≥350~460℃, ensuring that arsenic flue gas is treated within the optimal filtration temperature range. Under high-temperature conditions, it can effectively avoid the condensation and deposition of arsenic compounds during the filtration process, improve filtration efficiency and purification effect, and make the arsenic filtration rate ≥99.95%, ensuring the stability and efficiency of the entire treatment process, and enabling more precise separation of impurities and target substances in arsenic flue gas. 2. This invention uses 304 stainless steel fiber felt filter elements in pulse bag dust collectors. 304 stainless steel fiber felt has good high temperature resistance and corrosion resistance, and can adapt to the harsh environment of high temperature arsenic flue gas that may contain corrosive substances. The appropriate structural arrangement allows the filter element to fully exert its filtration function, increase the filtration area, improve filtration efficiency, ensure the long-term stable use of the filter element, extend the service life of the equipment, and reduce maintenance costs. 3. This invention features an air storage tank outside the pulse jet bag filter. The air outlet of the storage tank is connected to multiple blowpipes located directly above the filter. Electromagnetically controlled pulse valves are installed on the blowpipes, and tapered nozzles are positioned at the bottom of the blowpipes corresponding to the filter element location. This design makes the cleaning process more precise and effective. The tapered nozzles increase the airflow velocity, enhancing the cleaning effect and ensuring the continuity and efficiency of the filtration process. Simultaneously, it effectively removes dust from the filter element surface, maintaining its filtration performance. The removed dust falls into a conical ash hopper, and the ash discharge valve precisely controls the dust discharge, preventing dust accumulation in the ash hopper from affecting equipment operation and preventing secondary dust re-entry into the filtered flue gas. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a top view of the overall structure of the invention; Figure 3 This is a three-dimensional structural diagram of the feed pipe and the switching valve of the present invention; Figure 4 This is a three-dimensional structural diagram of the gas storage tank of the present invention; Figure 5 This is a three-dimensional structural diagram of the stainless steel fiber felt filter element of the present invention; Figure 6 This is a three-dimensional structural diagram of the blow pipe and blow nozzle of the present invention; Figure 7 This is a schematic diagram of the process for treating arsenic-containing flue gas and recovering arsenic according to the present invention.

[0020] Explanation of reference numerals in the attached figures: 1. Cyclone pre-separator; 2. Shell-and-tube heat exchanger; 3. Electric heater; 4. Pulse bag filter; 401. Stainless steel fiber felt filter element; 402. Air storage tank; 403. Pulse jet pipe; 404. Pulse valve; 405. Pulse nozzle; 406. Conical ash hopper; 407. Ash discharge valve; 5. Gradient sublimation furnace; 501. Low temperature zone; 502. Medium temperature zone; 503. High temperature zone; 6. Condensation system; 601. Primary condenser; 602. Secondary condenser; 603. Tertiary condenser; 604. Feed pipe; 605. Switch valve; 7. Spray absorption tower; 8. Activated carbon adsorption box; 9. Chimney. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0023] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0026] This invention provides, for example Figure 1-7 The device shown is a high-temperature filtration and purification device for arsenic flue gas, comprising an inlet system, a pretreatment system, a high-temperature filtration system, a purification system, a condensation system 6, and a tail gas treatment system connected in sequence according to the gas processing flow. The pretreatment system is equipped with a cyclone pre-separator 1 and a shell-and-tube heat exchanger 2. The outlet end of the cyclone pre-separator 1 is sealed to the inlet end of the shell-and-tube heat exchanger 2 by a flange. The shell-and-tube heat exchanger 2 is equipped with a spiral guide plate inside. A conical ash hopper is provided at the bottom of the cyclone pre-separator 1, and a pneumatic slide valve is installed on the ash hopper. The high-temperature filtration system is equipped with an electric heater 3 and a pulse bag filter 4. The inlet end of the electric heater 3 is connected to the outlet end of the shell-and-tube heat exchanger 2.

[0027] In this embodiment, the cyclone pre-separator 1 utilizes centrifugal force to cause particulate impurities to move towards the wall of the device during the rotation of the flue gas, eventually falling into the conical ash discharge hopper at the bottom. This achieves the initial separation of flue gas from large particulate impurities, which greatly reduces the burden on the subsequent high-temperature filtration system. Furthermore, the shell-and-tube heat exchanger 2 uses an external heat source to preheat the flue gas through heat exchange, thereby reducing the heating load on the subsequent electric heater 3. The spiral guide plate changes the flow state of the flue gas in the shell-and-tube heat exchanger 2, causing the flue gas to move forward in a spiral shape. This flow pattern enhances the turbulence of the fluid, disrupts the fluid boundary layer, and reduces thermal resistance, thus significantly improving the heat exchange efficiency. At the same time, the conical ash discharge hopper design allows the dust separated from the cyclone pre-separator 1 to slide down smoothly and be collected at the bottom of the ash discharge hopper. The conical structure facilitates the automatic accumulation of dust, avoiding uneven accumulation or dead corners in the ash discharge hopper, and providing convenience for subsequent ash discharge operations.

[0028] The outlet of the electric heater 3 is connected to a pulse bag filter 4. The pulse bag filter 4 includes a stainless steel fiber felt filter element 401. The stainless steel fiber felt filter element 401 is evenly distributed in an array inside the housing of the pulse bag filter 4. An air storage tank 402 is provided on the outside of the pulse bag filter 4. The outlet of the air storage tank 402 is connected to multiple blow pipes 403 located directly above the pulse bag filter 4. A pulse valve 404 is provided on the blow pipe 403, and the pulse valve 404 is electromagnetically controlled. A blow nozzle 405 is provided at the bottom of the blow pipe 403 corresponding to the position of the stainless steel fiber felt filter element 401. The outlet of the blow nozzle 405 has a tapered structure. A conical ash hopper 406 is provided at the bottom of the stainless steel fiber felt filter element 401. An ash discharge valve 407 is provided on the ash discharge pipe of the conical ash hopper 406.

[0029] In this embodiment, the electric heater 3 adopts a resistance wire heating structure with an adjustable power of 50-200kW and a stable outlet temperature of 400±5℃. The stainless steel fiber felt filter element 401 is made of 304 stainless steel felt with a filter element pore size of 0.5-2μm, a temperature resistance of ≤600℃, and a filtration area of ​​≥50m². The air storage tank 402 has a pressure of 0.6-0.8MPa, and the nozzle 405 has a pulse width of 50-100ms. The air storage tank 402 provides a stable air source for pulse cleaning. When cleaning is required, the electromagnetically controlled pulse valve 404 opens rapidly, and the compressed air in the air storage tank 402 is ejected at high speed through the blow pipe 403 and the gradually narrowing nozzle 405, forming a strong pulse airflow. This pulsed airflow can instantly impact the surface of the stainless steel fiber felt filter element 401, causing the dust adhering to the filter element to fall off, achieving efficient dust removal. The connection between the electric heater 3 and the pulse bag dust collector 4 makes the entire high-temperature filtration system a coherent whole, ensuring the temperature stability of the flue gas during the treatment process and the continuity of the process flow. It avoids the normal operation of the entire treatment system due to temperature fluctuations or flue gas interruptions. The conical ash hopper 406 can collect the dust that falls off the stainless steel fiber felt filter element 401 at the bottom, and periodically discharge the dust from the system through the ash discharge pipe and ash discharge valve 407, avoiding the accumulation of dust in the dust collector and affecting the normal operation of the equipment and the filtration effect.

[0030] The purification system is equipped with a gradient sublimation furnace 5, which has three internal zones: a low-temperature zone 501, a medium-temperature zone 502, and a high-temperature zone 503. The inlet of the low-temperature zone 501 is connected to the outlet of the pulse bag filter 4. The temperature of the low-temperature zone 501 is 350℃-400℃, the temperature of the medium-temperature zone 502 is 400℃-460℃, and the temperature of the high-temperature zone 503 is 460℃-550℃.

[0031] In this embodiment, the low-temperature zone 501, the medium-temperature zone 502, and the high-temperature zone 503 are each set with different temperature ranges to create a gradient heating environment. This gradient heating method is beneficial for the gradual sublimation and separation of arsenic and its impurities at different temperatures. In the low-temperature zone 501, some low-boiling-point impurities will sublimate first, while arsenic remains relatively stable. As the gas enters the medium-temperature zone 502, arsenic begins to gradually sublimate, while some higher-boiling-point impurities also sublimate in this area. In the high-temperature zone 503, arsenic can fully sublimate, while the remaining high-boiling-point impurities remain in the furnace, thereby achieving effective separation of arsenic from impurities and improving the purity of arsenic.

[0032] The condensing system 6 includes a primary condensing tower 601, a secondary condensing tower 602, and a tertiary condensing tower 603. The inlet of the primary condensing tower 601 is connected to the outlet of the intermediate temperature zone 502. The outlet of the primary condensing tower 601 is connected to the inlet of the secondary condensing tower 602. The outlet of the secondary condensing tower 602 is connected to the inlet of the tertiary condensing tower 603. The condensing system 6 also includes a feed pipe 604 and a switch valve 605. The feed pipe 604 is located at the bottom of the primary condensing tower 601, the secondary condensing tower 602, and the tertiary condensing tower 603. The switch valve 605 is located on the feed pipe 604.

[0033] In this embodiment, the primary condenser 601, secondary condenser 602, and tertiary condenser 603 are connected in series to form a staged condensation process. Arsenic vapor exiting from the intermediate temperature zone 502 of the gradient sublimation furnace 5 first enters the primary condenser 601. In the primary condenser 601, most of the higher-boiling-point impurities and some arsenic vapor condense into solids under the action of circulating cooling water, achieving preliminary separation and purification. The uncondensed arsenic vapor continues to enter the secondary condenser 602 for further condensation, causing more arsenic and impurities to condense. Finally, the remaining small amount of arsenic vapor undergoes deep condensation in the tertiary condenser 603 using the extremely low temperature of liquid nitrogen, ensuring almost complete condensation of the arsenic vapor and significantly improving the arsenic recovery rate and condensation efficiency. The feed pipe 604, located at the bottom of each condenser stage, provides a discharge channel for the solid arsenic product obtained from condensation. When a certain amount of solid arsenic accumulates in the condenser, the product can be smoothly discharged by opening the switch valve 605 on the feed pipe 604, facilitating collection and further processing. The exhaust gas treatment system includes a spray absorption tower 7 and an activated carbon adsorption box 8. The inlet of the spray absorption tower 7 is connected to the outlet of the three-stage condenser tower 603, and the outlet of the spray absorption tower 7 is connected to the inlet of the activated carbon adsorption box 8. The outlet of the activated carbon adsorption box 8 is connected to a chimney 9.

[0034] In this embodiment, the spray absorption tower 7 adopts a two-stage counter-current spray structure. The absorbent is a 5%-10% dilute nitric acid solution with a liquid-to-gas ratio of 1:20-1:30. When using dilute nitric acid solution as the absorbent, it can chemically react with arsenic compounds in the exhaust gas, such as arsenic trioxide and arsenous acid, oxidizing and dissolving them in the solution. Through this chemical reaction, gaseous arsenic compounds are effectively converted into liquid arsenates, thereby removing them from the exhaust gas. The dilute nitric acid solution can also react with other harmful gases in the exhaust gas, such as sulfur dioxide and nitrogen oxides. Sulfur dioxide reacts with dilute nitric acid to produce sulfuric acid and nitric oxide, and nitrogen oxides can also be converted and removed under the oxidation of dilute nitric acid. These reactions further purify the exhaust gas and reduce emissions. With fewer emissions of various harmful gases, and a suitable liquid-to-gas ratio ensuring sufficient absorbent liquid to contact and react with harmful substances in the exhaust gas, the humidity of the exhaust gas increases after treatment by the spray absorption tower 7. Appropriate humidity is beneficial for the adsorption of harmful substances by activated carbon in the subsequent activated carbon adsorption box 8, as a certain level of humidity can enhance the adsorption activity of the activated carbon surface and improve adsorption efficiency. As the final treatment step in the exhaust gas treatment system, the activated carbon adsorption box 8 can ensure that the exhaust gas meets emission standards under any circumstances. Finally, the chimney 9 safely and stably discharges the purified exhaust gas, after treatment by the spray absorption tower 7 and activated carbon adsorption box 8, into the atmosphere, allowing the exhaust gas to fully diffuse and dilute in the atmosphere, reducing its impact on the surrounding environment.

[0035] Working principle of this invention: Refer to the instruction manual appendix Figure 1 -Appendix Figure 7 In using this invention, firstly, flue gas containing arsenic and other impurities is introduced into the intake system and transported to the pretreatment system through pipelines. After entering the cyclone pre-separator 1, the flue gas is subjected to centrifugal force during rotation, causing particulate impurities to move towards the wall of the separator and eventually fall into the conical ash discharge hopper at the bottom, achieving preliminary separation of flue gas from large particulate impurities. When a certain amount of ash accumulates, the pneumatic gate valve is opened to discharge the ash. The flue gas from the cyclone pre-separator 1 enters the shell-and-tube heat exchanger 2, where it is preheated by an external heat source through heat exchange. The pretreated flue gas then enters the electric heater 3 for further processing. The flue gas is reheated and then enters the pulse bag dust collector 4. The stainless steel fiber felt filter element 401 filters out the tiny particles and impurities in the flue gas. When a dust removal operation is required, the electromagnetically controlled pulse valve 404 opens quickly, and the compressed air in the air storage tank 402 is ejected at high speed through the blow pipe 403 and the gradually narrowing blow nozzle 405, forming a strong pulse airflow. This pulse airflow can instantly impact the surface of the stainless steel fiber felt filter element 401, causing the dust adhering to the stainless steel fiber felt filter element 401 to fall off. The fallen dust falls into the conical ash hopper 406 and is periodically discharged through the ash discharge pipe and the ash discharge valve 407. The flue gas, after being filtered at high temperature, enters the low-temperature zone 501 of the gradient sublimation furnace 5, where the temperature is 350℃-400℃. At this temperature, some low-boiling-point impurities sublimate first, while arsenic remains relatively stable. The flue gas continues into the medium-temperature zone 502, where the temperature is 400℃-460℃. In this zone, arsenic begins to gradually sublimate, and some higher-boiling-point impurities also sublimate. Finally, the flue gas enters the high-temperature zone 503, where the temperature is 460℃-550℃. Under this high-temperature environment, arsenic can fully sublimate, while the remaining high-boiling-point impurities remain in the furnace, thus achieving effective separation of arsenic from impurities and improving the purity of arsenic. The arsenic vapor exiting the medium-temperature zone 502 of the gradient sublimation furnace 5 first enters the primary condenser 601. In the primary condenser 601... Most of the higher-boiling-point impurities and some arsenic vapor condense into solids under the action of circulating cooling water, achieving preliminary separation and purification. The uncondensed arsenic vapor continues to enter the secondary condenser 602 for further condensation, causing more arsenic and impurities to condense. Finally, the remaining small amount of arsenic vapor undergoes deep condensation in the tertiary condenser 603 using the extremely low temperature of liquid nitrogen, ensuring that the arsenic vapor is almost completely condensed, greatly improving the arsenic recovery rate and condensation efficiency. The feed pipe 604 provides a discharge channel for the solid arsenic product obtained from condensation. When a certain amount of solid arsenic accumulates in the condenser, the product can be smoothly discharged by opening the switch valve 605 on the feed pipe 604, facilitating collection and further processing. After condensation, the exhaust gas enters the spray absorption tower 7. The dilute nitric acid solution sprayed inside the spray absorption tower 7 can chemically react with arsenic compounds (such as arsenic trioxide, arsenous acid, etc.) in the exhaust gas, oxidizing and dissolving them in the solution. This effectively converts gaseous arsenic compounds into liquid arsenates, thereby removing them from the exhaust gas. At the same time, the dilute nitric acid solution can also react with other harmful gases in the exhaust gas, such as sulfur dioxide and nitrogen oxides, further purifying the exhaust gas and reducing the emission of various harmful gases. The exhaust gas exiting the spray absorption tower 7 enters the activated carbon adsorption box 8. The activated carbon in the activated carbon adsorption box 8 has a rich pore structure and a large specific surface area, which can adsorb the residual harmful substances in the exhaust gas. Finally, the purified exhaust gas after treatment by the spray absorption tower 7 and the activated carbon adsorption box 8 is safely and stably discharged into the atmosphere through the chimney 9.

[0036] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-temperature filtration and purification device for arsenic flue gas, comprising an inlet system, a pretreatment system, a high-temperature filtration system, a purification system, a condensation system (6), and a tail gas treatment system connected sequentially according to a gas processing flow, characterized in that: The pretreatment system is equipped with a cyclone pre-separator (1) and a shell-and-tube heat exchanger (2). The high-temperature filtration system is equipped with an electric heater (3) and a pulse bag filter (4). The inlet of the electric heater (3) is connected to the outlet of the shell-and-tube heat exchanger (2). The outlet of the electric heater (3) is connected to the pulse bag filter (4). The pulse bag filter (4) includes a stainless steel fiber felt filter element (401). The stainless steel fiber felt filter element (401) is evenly distributed in an array inside the housing of the pulse bag filter (4). An air storage tank (402) is provided on the outside of the pulse bag filter (4). The outlet of the air storage tank (402) is connected to multiple blow pipes (403) located directly above the pulse bag filter (4).

2. The high-temperature filtration and purification device for arsenic flue gas according to claim 1, characterized in that: The outlet end of the cyclone pre-separator (1) is connected to the inlet end of the shell-and-tube heat exchanger (2) by a flange seal, and the shell-and-tube heat exchanger (2) is provided with a spiral guide plate inside.

3. The high-temperature filtration and purification device for arsenic flue gas according to claim 2, characterized in that: The bottom of the cyclone pre-separator (1) is provided with a conical ash discharge hopper, and a pneumatic slide valve is installed on the ash discharge hopper.

4. The high-temperature filtration and purification device for arsenic flue gas according to claim 1, characterized in that: The blow pipe (403) is equipped with a pulse valve (404), and the pulse valve (404) is electromagnetically controlled. The bottom end of the blow pipe (403) is provided with a blow nozzle (405) corresponding to the position of the stainless steel fiber felt filter element (401), and the outlet of the blow nozzle (405) has a tapered structure.

5. The high-temperature filtration and purification device for arsenic flue gas according to claim 4, characterized in that: The bottom of the stainless steel fiber felt filter element (401) is provided with a conical ash hopper (406), and the ash discharge pipe of the conical ash hopper (406) is provided with an ash discharge valve (407).

6. The high-temperature filtration and purification device for arsenic flue gas according to claim 1, characterized in that: The purification system is equipped with a gradient sublimation furnace (5). The gradient sublimation furnace (5) has three internal zones: a low-temperature zone (501), a medium-temperature zone (502), and a high-temperature zone (503). The inlet of the low-temperature zone (501) is connected to the outlet of the pulse bag filter (4). The low-temperature zone (501) is 350℃-400℃, the medium-temperature zone (502) is 400℃-460℃, and the high-temperature zone (503) is 460℃-550℃.

7. The high-temperature filtration and purification device for arsenic flue gas according to claim 1, characterized in that: The condensation system (6) includes a primary condenser (601), a secondary condenser (602), and a tertiary condenser (603). The inlet of the primary condenser (601) is connected to the outlet of the medium temperature zone (502), the outlet of the primary condenser (601) is connected to the inlet of the secondary condenser (602), and the outlet of the secondary condenser (602) is connected to the inlet of the tertiary condenser (603).

8. The high-temperature filtration and purification device for arsenic flue gas according to claim 7, characterized in that: The condensation system (6) also includes a feed pipe (604) and a switch valve (605). The feed pipe (604) is located at the bottom of the primary condensation tower (601), the secondary condensation tower (602) and the tertiary condensation tower (603), and the switch valve (605) is located on the feed pipe (604).

9. The high-temperature filtration and purification device for arsenic flue gas according to claim 1, characterized in that: The exhaust gas treatment system includes a spray absorption tower (7) and an activated carbon adsorption box (8), with the inlet of the spray absorption tower (7) connected to the outlet of the three-stage condenser tower (603).

10. The high-temperature filtration and purification device for arsenic flue gas according to claim 9, characterized in that: The outlet of the spray absorption tower (7) is connected to the inlet of the activated carbon adsorption box (8), and the outlet of the activated carbon adsorption box (8) is connected to a chimney (9).

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