Dry flue gas desulfurization system and method based on simulated moving bed

Abstract

The invention discloses a system and a method for dry flue gas desulfurization based on a simulated moving bed, an adsorption tower and a regeneration double-tower process of the traditional dry flue gas desulfurization are combined into a single module unit adsorption regeneration tower process, the tower is composed of a plurality of module units with the same function, and the module units are similar in structure, are arranged in parallel and are mutually independent. A linkage switching valve is adopted for orderly switching of the working process, efficient coupling between the multi-module units in the tower and the heating medium circulating system, the refrigerant circulating system and the carrier gas injection system is achieved, and the adsorption regeneration technological process of continuous cooperation among the multi-module units is achieved. The gas phase flow direction is periodically changed through the linkage switching valve, meanwhile, the adsorbent is kept still in situ, the effect of simulating a moving bed through a fixed bed is achieved, the solid adsorbent is free of dynamic transfer and abrasion in the whole flow, the fixed bed can keep a good filling state, the gas phase is evenly distributed in the bed layer, and the product quality is stable. And large handling capacity and automatic operation can be conveniently realized.

Description

Technical Field

[0001] This invention relates to the field of dry flue gas desulfurization, specifically to a system and method for dry flue gas desulfurization based on a simulated moving bed. Background Technology

[0002] In existing technologies, the basic method of dry flue gas desulfurization technology is as follows: the raw flue gas enters the bottom of the adsorption tower and comes into cross-flow contact with the adsorbent. The adsorption tower is a moving bed, and the adsorbent moves from top to bottom. The raw flue gas comes into contact with the adsorbent, and harmful substances are adsorbed and removed. At the same time, the temperature inside the tower rises, and the purified flue gas is discharged from the top of the tower. After being pressurized by the purified flue gas fan, it is sent outside the boundary.

[0003] The saturated adsorbent discharged from the bottom of the adsorption tower is conveyed to the top of the regeneration tower by an elevator. The regeneration tower is a moving bed, where the saturated adsorbent moves from top to bottom, completing regeneration within the tower. Since the regeneration process is endothermic, a hot nitrogen circulation system is installed in the upper part of the regeneration tower, with heat provided by a nitrogen electric heater to heat the adsorbent. The adsorption process is exothermic, so an air cooling circulation system is installed in the lower part of the regeneration tower to cool the adsorbent. The SO2-rich gas regenerated from the top of the regeneration tower is pressurized by top and bottom carrier gas and conveyed to the middle of the regeneration tower. The SO2-rich gas is then drawn out from the middle of the regeneration tower, pressurized by an induced draft fan, and sent to the combustion furnace after passing through a dust collector. The regenerated adsorbent discharged from the bottom of the regeneration tower is screened by a vibrating screen to remove fine powder and then conveyed to the top of the adsorption tower by an elevator for recycling.

[0004] Patents CN106563356A and CN113477027A both utilize integrated adsorption and regeneration devices to achieve "in-situ regeneration of the adsorbent." However, the direct contact of high-temperature nitrogen with the adsorbent to complete the regeneration process increases the emission of SO2-rich gas, thereby increasing operating energy consumption and the processing capacity of subsequent devices. They do not take into account the precise heat control and balance of the entire adsorption and regeneration process. In addition, the switching between adsorption, regeneration, and cooling processes is controlled by multiple valves, resulting in numerous control links and a large workload for production and maintenance. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention discloses a system and method for flue gas desulfurization based on simulated moving bed dry process.

[0006] A system for dry flue gas desulfurization based on a simulated moving bed includes an adsorbent silo, a feed valve, an adsorption regeneration tower, a discharge valve, an upper-level linkage switching valve, a lower-level linkage switching valve, a hot circulating fan, a heater, a cooling circulating fan, a cooler, and a dust collector. The adsorbent silo, feed valve, adsorption regeneration tower, and discharge valve are connected sequentially. The upper-level linkage switching valve is connected to the adsorption regeneration tower, the hot circulating fan, the cooling circulating fan, and the dust collector. The hot circulating fan, heater, and lower-level linkage switching valve are connected sequentially. The cooling circulating fan and cooler... The coolant and the lower-level linkage switching valve are connected in sequence, and the lower-level linkage switching valve is connected to the adsorption regeneration tower. The adsorption regeneration tower includes a distribution pipe, a module unit, a vent valve and a collection hopper connected in sequence. The module unit includes a gas chamber, an adsorbent bed and tubes. The adsorbent bed is set in the gas chamber. The wall panel of the adsorbent bed adopts a spliced ​​grid plate. The adsorbent bed is filled with adsorbent. The top of the module unit is provided with an air extraction port. The tubes are vertically set in the adsorbent bed. The upper and lower ends of the tubes penetrate the bed. The gas chamber wall has an air inlet and an exhaust port.

[0007] Furthermore, both the upper-level and lower-level linkage switching valves are of a two-part structure, comprising a lower valve body, an external pipeline interface, an upper valve body, and a valve core. The external pipeline interface is located in the lower valve body and is used to connect to external pipelines. The valve core is located within the upper valve body and contains multiple connecting channels. These channels connect specific external pipeline interfaces in the lower valve body at specific valve position angles. This connection changes at different valve position angles. This valve structure and switching process achieve efficient coupling between the multiple module units inside the tower and the external heating medium nitrogen circulation system, cooling medium nitrogen circulation system, and carrier gas injection system. Through the synchronous operation of the upper-level and lower-level linkage switching valves, the working processes of each module unit inside the tower can be switched in an orderly manner. Each module unit will sequentially achieve the adsorption, regeneration, and cooling stages, maintaining a cyclical cycle.

[0008] The adsorption regeneration tower adopts a modular design, consisting of multiple functionally identical modular units. These units are connected in parallel and operate independently. They can be arranged either centrally in parallel within a single adsorption regeneration tower or distributed individually across multiple towers. During loading, the adsorbent flows from top to bottom through the distribution pipe, filling the bed layer by its own gravity. During unloading, a drain valve at the bottom of the bed discharges any remaining material into a collection hopper, and a discharge valve then transfers the remaining material from the collection hopper to the ash silo.

[0009] Furthermore, a tube inlet pipe is provided at the lower end of the tube, and a tube exhaust pipe is provided at the upper end of the tube. The tube inlet pipe is connected to the lower-level linkage switching valve, and the tube exhaust pipe is connected to the upper-level linkage switching valve.

[0010] Furthermore, the module unit also includes a guide plate, which is disposed between the gas chamber wall and the adsorbent bed wall.

[0011] Furthermore, the air inlet is located on the lower side of the module unit, and the exhaust port is located on the upper side of the module unit. The flue gas flows into the gas chamber through the air inlet and flows through the bed layer from bottom to top under the guidance of the guide plate. The gas flow direction is orthogonal to the bed layer feeding direction, and the purified gas is collected and flows out at the exhaust port of the module unit.

[0012] Furthermore, the upper-level and lower-level linkage switching valves are equipped with multiple valve position angles, which are always switched synchronously and remain the same. At each valve position angle during synchronous operation, the linkage switching valves achieve specific communication relationships with their external interfaces through internal communication channels.

[0013] Furthermore, the upper-level linkage switching valve and the lower-level linkage switching valve can be combined or separated. They can be combined into a single linkage switching valve or each can be further divided into multiple linkage switching valves. The linkage switching valves after changing the combination or separation method still need to maintain synchronization during operation.

[0014] When the pressure of the hot nitrogen and cold nitrogen circulation systems is insufficient, gas is supplied to the system from the outside.

[0015] A method for flue gas desulfurization based on simulated moving bed dry process, employing the aforementioned system for flue gas desulfurization based on simulated moving bed, includes the following steps:

[0016] 1) The adsorbent is stored in the adsorbent silo and fed into the top of the adsorption regeneration tower during feeding. It then flows by gravity into the adsorbent bed through the distribution pipe.

[0017] 2) During the adsorption process, the flue gas enters the inlet of the module unit through the lower linkage switching valve, flows through the bed and contacts the adsorbent. The harmful substances in the flue gas are adsorbed and removed, and the purified gas is discharged from the exhaust port. After passing through the upper linkage switching valve, it is sent to the dust collector for dust removal. The adsorption process is an exothermic reaction. Nitrogen gas is introduced into the bottom of the tube to regulate the bed temperature. The nitrogen gas enters the upper linkage switching valve from the top of the tube, and after passing through the cooling system, it is sent to the bottom of the tube for circulation through the lower linkage switching valve.

[0018] 3) During the regeneration process, the heated heat transfer medium nitrogen is introduced into the bottom of the tube through the lower linkage switching valve. After heat exchange, the nitrogen enters the upper linkage switching valve, is reheated, and then sent to the lower linkage switching valve to continue the next cycle. The regeneration process is an endothermic reaction. Regeneration and catalysis occur in the bed, which allows the adsorbent to be regenerated and volatile substances to be emitted. The carrier gas nitrogen enters the inlet through the lower linkage switching valve, flows through and purges the volatile substances in the bed, and the resulting mixed gas finally flows through the exhaust port and is discharged. At this time, the exhaust ports of each corresponding module unit are closed by the upper linkage switching valve.

[0019] 4) During the cooling process, the cooled refrigerant nitrogen is injected into the tube through the lower linkage switching valve. After heat exchange, it is sent into the cooling system through the upper linkage switching valve. After cooling, it flows back to the lower linkage switching valve to continue the next cycle. At this time, the air inlet, exhaust port and air extraction port of each corresponding module unit are closed.

[0020] 5) Each parallel module unit sequentially undergoes adsorption, regeneration, and cooling processes, maintaining a cyclical pattern;

[0021] 6) When unloading, the remaining material is unloaded into the collection hopper, and then the remaining material is sent from the collection hopper to the ash silo.

[0022] Due to the adoption of the above-mentioned technical methods and systems, the present invention has the following beneficial effects:

[0023] 1. The traditional dry flue gas desulfurization process of adsorption tower and regeneration dual tower is combined into a single modular adsorption and regeneration tower process. This tower is composed of multiple modular units with the same function. Each modular unit has a similar structure, is arranged in parallel and is independent of each other. Overall, it reduces equipment investment, land occupation and capital investment, simplifies the process flow and reduces the difficulty of operation.

[0024] 2. Heat exchange tubes are installed in the adsorption regeneration tower bed to achieve precise heat control and balance throughout the adsorption regeneration process through indirect heat exchange between the bed and the heat / cooling medium, ensuring the safe operation of the bed.

[0025] 3. Heat exchange tubes are installed in the adsorption regeneration tower bed to isolate the heat / cooling medium gas from the flue gas, minimizing the emission of mixed gas, reducing operating energy consumption and the processing capacity of subsequent equipment.

[0026] 4. The working process is switched in an orderly manner by using a linkage switching valve, which realizes the efficient coupling between the multiple module units inside the tower and the auxiliary systems outside the tower: the hot medium circulation system, the cold medium circulation system, and the carrier gas injection system. This enables the adsorption and regeneration process to be continuously coordinated among the multiple module units, which is simple to operate and easy to coordinate production.

[0027] 5. Each module of the adsorption regeneration tower is equipped with a vertical fixed bed filled with adsorbent. During the continuous adsorption and regeneration process, multiple linked switching valves periodically change the gas phase flow direction while the adsorbent remains stationary in place, achieving the effect of a fixed bed simulating a moving bed. Throughout the process, the solid adsorbent experiences no dynamic transport or wear, the fixed bed maintains a good filling state, the gas phase is uniformly distributed within the bed, product quality is stable, and it facilitates high-volume processing and automated operation. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the system flow of the present invention;

[0029] Figure 2 This is a schematic diagram of the adsorption regeneration tower structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the linkage switching valve structure of the present invention;

[0031] In the diagram: 1. Adsorbent silo; 2. Feed valve; 3. Adsorption regeneration tower; 31. Distribution pipe; 21. Module unit A; 22. Module unit B; 23. Module unit C; 24. Module unit D; 33. Adsorbent bed; 34. Tube; 35. Gas chamber; 36. Relief valve; 37. Collection hopper; 38. Guide plate; 41. Air inlet; 42. Air outlet; 43. Air extraction port; 45. Discharge valve; 5. Linkage switching valve; 51. Upper linkage switching valve; 52. Lower linkage switching valve; 55. Lower valve body flap; 56. External pipeline interface; 57. Upper valve body flap; 58. Valve core; 6. Hot air circulation fan; 7. Heater; 8. Cooling circulation fan; 9. Cooler; 10. Dust collector;

[0032] Pipelines in the diagram: 101, Flue gas inlet pipe 1; 102, Flue gas inlet pipe 2; 103, Flue gas exhaust pipe 3; 104, Flue gas exhaust pipe 4; 121, Module unit A inlet pipe; 122, Module unit B inlet pipe; 123, Module unit C inlet pipe; 124, Module unit D inlet pipe; 141, Module unit A exhaust pipe; 142, Module unit B exhaust pipe; 143, Module unit C exhaust pipe; 144, Module unit D exhaust pipe; 161, Module unit A extraction pipe; 162, Module unit B extraction pipe; 163, Module unit C extraction pipe; 164, Module unit D extraction pipe; 13 1. Module Unit A tube inlet pipe; 132. Module Unit B tube inlet pipe; 133. Module Unit C tube inlet pipe; 134. Module Unit D tube inlet pipe; 151. Module Unit A tube exhaust pipe; 152. Module Unit B tube exhaust pipe; 153. Module Unit C tube exhaust pipe; 154. Module Unit D tube exhaust pipe; 181. Hot air circulation fan inlet pipe; 182. Reheat gas pipe; 191. Cooling circulation fan inlet pipe; 192. Recooled gas pipe; 196. Hot medium nitrogen circulation system make-up gas pipe; 198. Cold medium nitrogen circulation system make-up gas pipe; 199. Carrier gas injection pipe. Detailed Implementation

[0033] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments are merely specific illustrations of the present invention, intended to enable those skilled in the art to better understand the technical solutions of this application, and should not be regarded as limitations on the present invention.

[0034] like Figure 1 , Figure 2 , Figure 3As shown, the present invention discloses a method and system for dry flue gas desulfurization based on a simulated moving bed, wherein the adsorption regeneration tower 3 has the following characteristics:

[0035] The adsorbent is stored in the adsorbent silo 1 and enters the top of the adsorption-regeneration tower 3 via the feed valve 2. The adsorption-regeneration tower 3 is a fixed bed composed of multiple functionally identical modular units. Each modular unit has a similar structure, is arranged in parallel, and is independent of the others. Each modular unit has a vertical bed layer with a modular grid plate as the bed wall panel, and the bed layer is filled with adsorbent. A distribution pipe 31 is located at the upper end of the bed layer, and a discharge valve 36 is located at the lower end of the bed layer. The operation of each modular unit is controlled by a linkage switching valve to complete the adsorption, regeneration, and cooling processes respectively. When the adsorbent is loaded, it moves from top to bottom in the tower and flows into the bed layer by gravity through the distribution pipe 31. When the adsorbent is unloaded, it also moves from top to bottom. The discharge valve 36 at the bottom of the bed layer discharges the remaining material into the collection hopper 37, and the discharge valve 45 then sends the remaining material from the collection hopper 37 to the ash silo.

[0036] In this embodiment, the adsorption-regeneration tower 3 consists of four module units, all centrally and uniformly arranged. Module units A21, B22, C23, and D24 have vertical tubes 34 within their beds. These tubes 34 are arranged vertically side-by-side along the bed, penetrating the bed at both ends to exchange heat with it during adsorption, regeneration, and cooling processes. The lower ends of each module unit's tubes 34 are connected to the tube inlet pipes (131, 132, 133, and 134), and the upper ends are connected to the tube exhaust pipes (151, 152, 153, and 154).

[0037] Each module unit is equipped with an air inlet 41 and an exhaust outlet 42. Gas flows into the inner cavity of the module unit through the air inlet 41 and flows through each stage of the bed under the guidance of the guide plate 38. In this embodiment, three stages of the bed are set up. The gas passes through the adsorbent bed 33 three times in sequence. The gas flow direction is orthogonal to the bed feeding direction. After passing through the three stages of the bed, the gas is collected at the exhaust outlet 42 of the module unit and flows out under the guidance of the guide plate 38. At the same time, the top of the last stage of the bed of each module unit is equipped with an air extraction outlet 43.

[0038] Module units A21, B22, C23, and D24 all undergo three processes in sequence: adsorption, regeneration, and cooling, and maintain a cyclical process.

[0039] During the adsorption process, the raw flue gas enters from outside the boundary area, passes through the lower-level linkage switching valve 52, and then flows into the inner cavity of each module unit through the inlet pipes (121, 122, 123, and 124) of each module unit. Guided by the guide plate 38, it penetrates the primary adsorbent bed 33 perpendicular to the bed feeding direction. Under the action of adsorption, catalysis, and filtration, harmful substances in the flue gas are removed. Then it flows into the primary intermediate gas chamber 35. Due to the obstruction of the guide plate 38, the flue gas continues to penetrate the secondary adsorbent bed 33. After chemical and physical processes, it flows into the secondary... After the intermediate gas chamber 35 continues to penetrate the three-stage adsorbent bed 33, the purified flue gas is collected and discharged at the module unit exhaust port 42. At this time, the control valves corresponding to the extraction ports 43 of each module unit are closed, and the extraction pipes (161, 162, 163 and 164) of each module unit are cut off. After the purified flue gas is discharged from the adsorption regeneration tower 3, it is sent to the dust collector 10 through the exhaust pipes (141, 142, 143 and 144) of each module unit by the upper linkage switching valve 51. The purified gas after dust removal is sent to the purified gas induced draft fan and then sent out. The dust removed by the dust collector 10 is sent to the ash silo.

[0040] During the adsorption process, the refrigerant nitrogen circulation system operates as follows: the cooled refrigerant nitrogen first flows through the lower-level linkage switching valve 52, through the inlet pipes (131, 132, 133 and 134) of each module unit tube, and is injected into the heat exchange tubes 34 of each module unit. The refrigerant nitrogen cools the adsorbent bed 33 through the heat exchange tubes 34, suppressing the reaction temperature rise and ensuring the safe operation of the bed. After heat exchange, the refrigerant nitrogen flows through the exhaust pipes (151, 152, 153 and 154) of each module unit tube, through the upper-level linkage switching valve 51, the cooling circulation fan inlet pipe 191 and the cooling circulation fan 8 in sequence. The cooling circulation fan 8 pressurizes the nitrogen and sends it to the cooler 9. After cooling, the nitrogen re-enters the lower-level linkage switching valve 52 through the recooling gas pipe 192 to continue the next cycle. When the pressure of the refrigerant nitrogen circulation system is insufficient, the refrigerant nitrogen circulation system replenishment pipe 198 replenishes the system.

[0041] During the regeneration process, the working process of the heat transfer medium nitrogen circulation system is as follows: the heated heat transfer medium nitrogen first flows through the lower linkage switching valve 52, through the air inlet pipes (131, 132, 133 and 134) of each module unit tube, and is injected into the heat exchange tubes 34 of each module unit. The heat transfer medium nitrogen heats the adsorbent bed 33 through the heat exchange tubes 34, and regeneration and catalysis occur in the bed, and harmful substances are emitted, thus regenerating the adsorbent. After heat exchange, the heat transfer medium nitrogen flows through the exhaust pipes (151, 152, 153 and 154) of each module unit tube, and sequentially through the upper linkage switching valve 51, the heat circulation fan inlet pipe 181 and the heat circulation fan 6. The heat circulation fan 6 pressurizes the nitrogen and sends it to the heater 7. After heating, the nitrogen re-enters the lower linkage switching valve 52 through the reheat gas pipe 182 to continue the next cycle. When the pressure of the nitrogen circulation system is insufficient, nitrogen is supplied to the system through the nitrogen circulation system replenishment pipe 196.

[0042] During the regeneration process, the carrier gas injection system operates as follows: Nitrogen carrier gas from outside the boundary area enters through the carrier gas injection pipe 199 and the lower-level linkage switching valve 52, then flows through the inlet pipes (121, 122, 123, and 124) of each module unit, and into the inner cavity of each module unit through the inlet port 41. Guided by the guide plate 38, it penetrates the primary adsorbent bed 33 perpendicular to the bed feeding direction, purging out harmful substances volatilized from the bed. Then, it flows into the primary intermediate gas chamber 35. Due to the obstruction of the guide plate 38, the carrier nitrogen gas continues to penetrate the secondary adsorbent bed 33 and flows into the secondary intermediate gas chamber 35. After the carrier nitrogen gas continues to penetrate the tertiary adsorbent bed 33, the resulting mixed gas is collected at the extraction ports 43 of each module unit and discharged through the extraction pipes (161, 162, 163 and 164) of each module unit. The exhaust pipes (141, 142, 143 and 144) of each module unit, which are connected to the exhaust ports 42 of each module unit, are closed by the upper linkage switching valve 51 at this time.

[0043] During the cooling process, the refrigerant nitrogen circulation system operates as follows: the cooled refrigerant nitrogen first flows through the lower linkage switching valve 52, through the inlet pipes (131, 132, 133 and 134) of each module unit tube, and is injected into the heat exchange tubes 34 of each module unit. The refrigerant nitrogen cools the adsorbent bed 33 through the heat exchange tubes 34. After heat exchange, the refrigerant nitrogen flows through the exhaust pipes (151, 152, 153 and 154) of each module unit tube, and sequentially through the upper linkage switching valve 51, the cooling circulation fan inlet pipe 191 and the cooling circulation fan 8. The cooling circulation fan 8 pressurizes the nitrogen and sends it to the cooler 9. After cooling, the nitrogen re-enters the lower linkage switching valve 52 through the recooling gas pipe 192 to continue the next cycle. When the pressure of the refrigerant nitrogen circulation system is insufficient, the refrigerant nitrogen circulation system replenishment pipe 198 replenishes the system.

[0044] During the cooling process, the air inlet pipes (121, 122, 123 and 124) of each module unit connected to the air inlet 41 of each module unit are closed by the lower linkage switching valve 52, the exhaust pipes (141, 142, 143 and 144) of each module unit connected to the exhaust port 42 of each module unit are closed by the upper linkage switching valve 51, and the air extraction pipes (161, 162, 163 and 164) of each module unit connected to the air extraction port 43 of each module unit are closed by the control valve.

[0045] The aforementioned linkage switching valve has the following characteristics:

[0046] The linkage switching valve consists of an upper linkage switching valve 51 and a lower linkage switching valve 52. The two have the same structure. By synchronizing their operation, the working process of each module unit in the tower can be switched in an orderly manner, and each module unit will sequentially realize the adsorption, regeneration and cooling processes.

[0047] The upper-position linkage switching valve 51 and the lower-position linkage switching valve 52 are of a two-part structure. The lower part 55 of the valve body is used to connect with external pipelines and has multiple external pipeline interfaces 56. The upper part 57 of the valve body contains the switching valve core 58. The valve core 58 has multiple connecting channels, which are used to connect specific external interfaces of the lower part to each other at a specific valve position angle.

[0048] The synchronous operation of the upper-position linkage switching valve 51 and the lower-position linkage switching valve 52 is as follows: The upper-position linkage switching valve 51 and the lower-position linkage switching valve 52 have four valve position angles: 0°, 90°, 180°, and 270°. Before valve operation, the valve position angles of the upper-position linkage switching valve 51 and the lower-position linkage switching valve 52 remain the same, and during valve operation, the upper-position linkage switching valve 51 and the lower-position linkage switching valve 52 remain synchronized, achieving orderly switching between the multi-module units inside the tower and the external heating medium nitrogen circulation system, cooling medium nitrogen circulation system, and carrier gas injection system. The upper valve core 58 of the upper-position linkage switching valve 51 and the lower-position linkage switching valve 52 has multiple connecting channels. These channels are used to connect specific external interfaces of the lower valve core at specific valve position angles. This connection relationship changes periodically with different valve position angles.

[0049] The working process of each module unit and the sequence of their interrelationships at each valve position angle of the upper-level linkage switching valve 51 and the lower-level linkage switching valve 52 are shown in Table 1 below:

[0050] Table 1. Working process and sequence of each module unit

[0051] Serial Number Linkage switching valve 0° position Linkage switching valve 90° position 180° position of the linkage switching valve 270° position of the linkage switching valve Module Unit A Adsorption regeneration cool down Adsorption Module Unit B Adsorption Adsorption regeneration cool down Module Unit C cool down Adsorption Adsorption regeneration Module Unit D regeneration cool down Adsorption Adsorption

[0052] During the operation of each module unit as described in Table 1, the interconnection relationship of the external interfaces of the linkage switching valve 5 under each valve position angle of the synchronously operating linkage switching valve is shown in Table 2 below:

[0053] Table 2. Connection relationships of the external interfaces of the linkage switching valve

[0054]

[0055]

[0056]

[0057] Through the interconnection between the external interfaces of the upper linkage switching valve 51 and the lower linkage switching valve 52, the efficient coupling between each module unit inside the tower and the external heat medium nitrogen circulation system, cold medium nitrogen circulation system, and carrier gas injection system is realized. Thus, each module unit inside the tower undergoes three processes in sequence: adsorption, regeneration, and cooling, and maintains a cyclical cycle.

[0058] The parts of this invention not described in detail are prior art.

[0059] The embodiments selected herein for the purpose of disclosing the inventive objectives are currently considered suitable; however, it should be understood that the invention is intended to include all variations and modifications of the embodiments that fall within the scope of this concept and invention.

Claims

1. A system and method for dry flue gas desulfurization based on simulated moving bed, characterized in that: The adsorbent bin, the feeding valve, the adsorption regeneration tower, the discharging valve, the upper linkage switching valve, the lower linkage switching valve, the hot circulating fan, the heater, the cooling circulating fan, the cooler and the dust remover are sequentially connected.

2. The system for dry flue gas desulphurization based on simulated moving bed according to claim 1, characterized in that: The upper linkage switching valve and the lower linkage switching valve are both of upper and lower two-piece structure, and each comprises a valve body lower piece, an external pipeline interface, a valve body upper piece and a valve core.

3. The simulated moving bed dry flue gas desulfurization based system as claimed in claim 1, wherein: The adsorption regeneration tower is designed in the form of a module unit, and a plurality of module units are connected in parallel.

4. The simulated moving bed dry flue gas desulfurization based system as claimed in claim 1, wherein: The module units can be arranged in parallel in a single adsorption regeneration tower or arranged separately in a plurality of adsorption regeneration towers.

5. The simulated moving bed dry flue gas desulfurization based system as claimed in claim 1, wherein: The lower end of the column tube is provided with a column tube air inlet pipe, and the upper end of the column tube is provided with a column tube air outlet pipe.

6. The simulated moving bed dry flue gas desulfurization based system as claimed in claim 1, wherein: The module unit further comprises a flow guide plate arranged between the gas chamber wall and the adsorbent bed wall.

7. The system for dry flue gas desulphurization based on simulated moving bed according to claim 6, characterized in that: The gas inlet is located on the lower side of the module unit, and the gas outlet is located on the upper side of the module unit.

8. The simulated moving bed dry flue gas desulfurization system according to claim 2, characterized in that: The upper linkage switching valve and the lower linkage switching valve are provided with a plurality of valve position angles.

9. The simulated moving bed dry flue gas desulfurization based system as claimed in claim 2, wherein: The upper linkage switching valve and the lower linkage switching valve can be combined or divided into a single linkage switching valve or a plurality of linkage switching valves.

10. A process for dry flue gas desulfurization based on simulated moving bed, characterized in that, The steps include: 1) The adsorbent is stored in the adsorbent bin and fed into the top of the adsorption regeneration tower during feeding, and then flows into the adsorbent bed through the distribution pipe. 2) During the adsorption process, flue gas enters the module unit inlet through the lower linkage switch valve, flows through the bed layer and contacts the adsorbent, the harmful substances in the flue gas are removed by adsorption, and the purified gas is discharged from the exhaust port and sent to the dust collector for dust removal after the upper linkage switch valve; the adsorption process is an exothermic reaction, and the column bottom is supplied with coolant nitrogen to regulate the bed temperature, nitrogen enters the upper linkage switch valve from the column top, and then passes through the cooling system and is sent to the column bottom through the lower linkage switch valve to circulate; 3) During the regeneration process, the heated hot medium nitrogen enters the column bottom through the lower linkage switch valve, and after heat exchange, the nitrogen enters the upper linkage switch valve, is heated again, and is sent to the lower linkage switch valve for the next cycle; The regeneration process is an endothermic reaction, and the bed layer undergoes regeneration and catalysis, so that the spent adsorbent can be regenerated, and volatile substances are discharged, the carrier gas nitrogen enters the inlet through the lower linkage switch valve, flows through and purges the volatile substances in the bed layer, and the mixed gas formed finally flows through the exhaust port and is discharged, at this time the exhaust port of each corresponding module unit is closed by the upper linkage switch valve; 4) During the cooling process, the cooled coolant nitrogen is injected into the column through the lower linkage switch valve, and after heat exchange, it is sent to the cooling system through the upper linkage switch valve, and then it is returned to the lower linkage switch valve for the next cycle, at this time the inlet, exhaust port and exhaust port of each corresponding module unit are closed; 5) Each parallel module unit sequentially undergoes adsorption, regeneration and cooling processes and maintains periodic circulation; 6) When discharging, the remaining material is discharged into the collection hopper, and then the remaining material is sent from the collection hopper to the ash bin.

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