A dry purification system and method for primary air of a sintering flue gas and waste heat utilization device

Abstract

The application discloses a dry purification system and method for primary air of a sintering flue gas and waste heat utilization device, and belongs to the technical field of environmental protection equipment. A dry purification system is arranged before sintering flue gas enters a CFB boiler primary air fan, and the dry purification system comprises a circulating fluidized bed reactor and a conditioning bag dust collector. After alkali earth metals and iron oxide dust in the sintering flue gas are wrapped by a thousand times of circulating materials of the circulating fluidized bed reactor, the wrapped materials are removed through the conditioning bag dust collector, and the sulfur oxides in the flue gas are removed. The purified sintering flue gas enters the CFB boiler as primary air, and problems of coking and blocking of a primary air cap and corrosion of a primary air duct will not occur any more, so that the CFB boiler and the whole system can be stably and reliably operated.

Description

Technical Field

[0001] This application relates to the field of environmental protection equipment technology, and in particular to a dry purification system and method for primary air of a sintering flue gas co-process waste heat utilization device. Background Technology

[0002] The sintering flue gas co-process waste heat utilization technology uses sintering flue gas as the primary and secondary air of a CFB (circulating fluidized bed boiler) boiler, which is then fed into the furnace to aid combustion. This process can remove dioxins, CO, and VOCs from the sintering flue gas and fully utilize the heat of the sintering flue gas, resulting in good synergistic benefits.

[0003] However, the sintering flue gas contains alkaline earth metals, iron oxide dust, and sulfur oxides. When it enters the CFB boiler's air cap as primary air, it melts and cokes due to the high temperature, clogging the air cap and causing flow deviation and excessive resistance in the CFB boiler system, leading to unstable operation. Simultaneously, the sintering flue gas contains sulfur oxides and acidic gases, and has high humidity. After being pressurized by the primary air fan, it becomes positive pressure, easily causing corrosion and leakage in the primary air duct, resulting in the uncontrolled emission of large amounts of pollutants. Summary of the Invention

[0004] This application provides a dry purification system and method for primary air in a sintering flue gas co-processing waste heat utilization device. It solves the problem in the prior art where sintering flue gas, when used as primary air, enters the air cap of a CFB boiler and, due to high temperature, melts and cokes, clogging the primary air cap and causing flow field deviation, excessive resistance, and unstable operation of the CFB boiler system. The technical solution is as follows: On the one hand, a dry purification system for the primary air of a sintering flue gas co-processing waste heat utilization device is provided. It is equipped with two flue gas circulation channels, a CFB boiler, and a flue gas treatment unit; One of the flue gas flow channels is equipped with a fluidized bed reactor, a conditioning bag filter, and a primary air fan connected in sequence. The primary air in the flue gas flow channel is used to adsorb sulfur oxides and other acidic gases and complete the acid-base neutralization reaction in the fluidized bed reactor; dust removal is performed in the conditioning bag filter; and the primary air fan is used to introduce the treated primary air from the bottom of the CFB boiler into the furnace of the CFB boiler. A secondary air fan is installed on the other flue gas circulation channel, and the secondary air fan is used to introduce secondary air into the main combustion zone of the CFB boiler; The flue gas treatment unit is used to desulfurize and remove dust from the flue gas discharged from the CFB boiler before discharging it.

[0005] Optionally, the flue gas treatment unit is used to collect and recycle the desulfurizing agent and transport it to the fluidized bed reactor as a desulfurization absorbent.

[0006] Optionally, the flue gas treatment unit includes: a pre-electrostatic precipitator, a desulfurization reactor, and a bag filter connected in sequence. The inlet of the pre-electrostatic precipitator is connected to the CFB boiler, and the bag filter is connected to the fluidized bed reactor to deliver the recycled desulfurizing agent to the fluidized bed reactor.

[0007] Optionally, a pipe is provided between the bottom ash discharge port of the bag filter and the fluidized bed reactor, and the ash discharge pump in the bag filter transports the recycled desulfurizing agent to the fluidized bed reactor through the pipe.

[0008] Optionally, the dry purification system of the primary air of the sintering flue gas co-process waste heat utilization device is provided with a first pipe and a second pipe connected to the sintering machine. One end of the first pipe is connected to the fluidized bed reactor, and the second pipe is connected to the secondary air fan and the CFB boiler. The sintering flue gas from the sintering machine is diverted through the first pipe and the second pipe, respectively.

[0009] Optionally, a circulating fluidized bed chute is provided between the conditioning bag filter and the fluidized bed reactor, the circulating fluidized bed chute being used to recycle the ash from the ash hopper in the conditioning bag filter back to the fluidized bed reactor.

[0010] On the other hand, a dry purification method for primary air of a sintering flue gas co-processing waste heat utilization device is provided. The method includes: introducing a sintering flue gas into a fluidized bed reactor to adsorb sulfur oxides and other acidic gases and complete an acid-base neutralization reaction. The flue gas that has completed the acid-base neutralization reaction is introduced into a conditioning bag filter for dust removal; The primary air after dust removal is introduced into the furnace of the CFB boiler from the bottom through a primary air fan.

[0011] Optionally, after the flue gas treatment unit desulfurizes and removes dust from the flue gas discharged from the CFB boiler, the method further includes: the flue gas treatment unit collecting and recycling the desulfurizing agent and conveying it to the fluidized bed reactor as a desulfurization absorbent.

[0012] Optionally, when the flue gas treatment unit includes a pre-electrostatic precipitator, a desulfurization reactor, and a bag filter connected in sequence, the step of the flue gas treatment unit collecting and recycling desulfurizing agent and conveying it to the fluidized bed reactor as a desulfurization absorbent includes: the bag filter is connected to the fluidized bed reactor to convey the recycled desulfurizing agent in the ash hopper of the bag filter to the fluidized bed reactor.

[0013] Optionally, the method further includes: circulating ash from the ash hopper in the conditioning bag filter into the fluidized bed reactor.

[0014] The beneficial effects of the technical solutions provided in this application include at least the following: (1) A dry purification system is set up before the sintering flue gas enters the primary air fan of the CFB boiler. The system includes a circulating fluidized bed reactor and a conditioning bag filter. The circulating fluidized bed reactor uses thousands of times the amount of circulating material to wrap the alkaline earth metal and iron oxide dust in the sintering flue gas. The dust is then removed by the conditioning bag filter. The sulfur oxides in the flue gas can be removed. The purified sintering flue gas enters the CFB boiler as primary air. The problem of coking and blockage of the primary air cap and corrosion of the primary air duct will no longer occur. This ensures that the CFB boiler and the entire system can operate stably and reliably.

[0015] (2) After the flue gas from the CFB boiler outlet is precipitated by the pre-electrostatic precipitator, the recycled desulfurizing agent collected by the desulfurization reactor and bag filter is re-entered into the fluidized bed reactor of the primary air to complete desulfurization and acid gas removal, and then enters the conditioning bag filter of the primary air to complete the flue gas dust conditioning and removal process. The flue gas volume after the CFB boiler is larger, and the recycled desulfurizing agent collected by the desulfurization reactor and bag filter can meet the usage requirements without increasing the consumption of desulfurizing agent. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the structure of a dry purification system for primary air of a sintering flue gas co-process waste heat utilization device provided in an embodiment of this application; Figure 2 This is a schematic flowchart of a primary air drying and purification method for a sintering flue gas co-processing waste heat utilization device provided in an embodiment of this application.

[0018] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0021] Specifically, the primary air duct clogging problem is severe, making it difficult for CFB boilers to operate stably and reliably. In the current process, the sintering flue gas only undergoes electrostatic precipitator treatment at the turbine head, resulting in a still high dust concentration. Since the primary air duct vents are small, this dust still accumulates on the vent vents and melts and cokes under the high temperature of the furnace, gradually clogging the vent vents. This leads to high primary air resistance, uneven air distribution, and consequently, poor CFB boiler operation. The existing sintering flue gas co-processing waste heat recovery device experiences widespread duct clogging within less than a month of operation, forcing the boiler to be shut down for cleaning. With thousands of vents in a single boiler, the cleaning process is time-consuming and involves a significant amount of maintenance work.

[0022] Sintering flue gas contains sulfur oxides and acidic gases. Positive pressure operation of the primary air duct leads to flue corrosion and fugitive emissions of pollutants: Sintering flue gas contains corrosive gases such as SO2, SO3, and HCl, and the flue gas has high humidity. After being subjected to positive pressure by the primary air fan, it is easy to cause corrosion of the primary air duct, resulting in problems such as leaks and unorganized emissions of pollutants.

[0023] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a dry purification system for primary air in a sintering flue gas co-processing waste heat utilization device provided in an embodiment of this application. The dry purification system for primary air in this sintering flue gas co-processing waste heat utilization device includes two flue gas flow channels, a CFB boiler 10, and a flue gas treatment unit 20.

[0024] A flue gas flow channel L1 can be equipped with a fluidized bed reactor 30, a conditioning bag filter 40, and a primary air fan 50 connected in sequence. The primary air in the flue gas flow channel L1 undergoes adsorption of sulfur oxides and other acidic gases and completes acid-base neutralization within the fluidized bed reactor 30; dust removal is performed within the conditioning bag filter 40. The primary air fan 50 is used to introduce the primary air, after treatment by the fluidized bed reactor 30 and the conditioning bag filter 40, into the furnace of the CFB boiler 10 from the bottom. Here, the sintering flue gas, as primary air, needs to enter the CFB boiler 10 through the air caps (not shown in the figure) on the air distribution plate.

[0025] A secondary air fan 60 is installed on another flue gas circulation channel L2, which can be used to introduce secondary air into the main combustion zone of the CFB boiler 10.

[0026] The flue gas treatment unit 20 in the dry purification system of the primary air of the sintering flue gas co-processing waste heat utilization device is used to desulfurize and remove dust from the flue gas discharged from the CFB boiler 10 before discharge.

[0027] In this embodiment, a dry purification system is installed before the primary air fan 50 of the sintering flue gas Y enters the CFB boiler 10. This system includes a circulating fluidized bed reactor 30 and a conditioning bag filter 40. The fluidized bed reactor 30 uses thousands of times the amount of circulating material to encapsulate the alkaline earth metals and iron oxide dust in the sintering flue gas, which is then removed by the conditioning bag filter 40. This process also removes sulfur oxides from the flue gas. The purified sintering flue gas then enters the CFB boiler 10 as primary air, eliminating the problems of primary air cap coking and duct corrosion, thus ensuring the stable and reliable operation of the CFB boiler 10 and the entire system. Additionally, one path serves as secondary air, passing through a secondary air fan 60 directly into the main combustion zone of the CFB boiler 10 for combustion support, reducing system investment costs.

[0028] Specifically, the primary air fluidized bed reactor 30 and the primary air conditioning bag filter 40 utilize the advantages of the recycled desulfurizing agent as a calcium absorbent to remove sulfur oxides and other acidic gases, significantly reducing the risk of primary air duct corrosion. They also complete the conditioning and dust removal process for alkaline earth metal and iron oxide dust, ensuring that the primary air entering the boiler meets the requirements for CFB boiler combustion and stable fluidization, thus significantly reducing the risk of primary air duct corrosion.

[0029] In summary, this application provides a dry purification system for the primary air of a sintering flue gas co-processing waste heat utilization device. A fluidized bed reactor, a conditioning bag filter, and a primary air fan are sequentially connected in one flue gas flow channel. A dry purification system, including a circulating fluidized bed reactor and a conditioning bag filter, is installed before the sintering flue gas enters the CFB boiler's primary air fan. The circulating fluidized bed reactor uses thousands of times more circulating material to encapsulate alkaline earth metals and iron oxide dust in the sintering flue gas, which are then removed by the conditioning bag filter. Sulfur oxides in the flue gas are also removed. The purified sintering flue gas enters the CFB boiler as primary air, eliminating the problems of primary air cap coking and duct corrosion, thus ensuring stable and reliable operation of the CFB boiler and the entire system. Additionally, one channel serves as secondary air, directly entering the main combustion zone of the CFB boiler for combustion support. This portion of the flue gas requires no treatment, reducing system investment costs.

[0030] In this application, the circulating fluidized bed reactor 30 contains a calcium-based alkaline absorbent, a Venturi device, and nozzles (not shown in the figure). The calcium-based alkaline absorbent is sprayed into the expansion section of the Venturi device in powder form, while atomized water is sprayed into the nozzles simultaneously. The desulfurization method in this application employs dry desulfurization, for example, using sodium bicarbonate (baking soda, NaHCO3) as the adsorbent for flue gas desulfurization, also known as a desulfurizing agent. It removes acidic pollutants (mainly SO2, and contains small amounts of SO3, HF, and HCl) from the flue gas through chemical adsorption, and can also remove some organic and inorganic trace substances through physical adsorption. After passing through the fluidized bed reactor, the flue gas directly enters the conditioning bag filter. The flue gas entering the conditioning bag filter carries unreacted alkaline powders (e.g., NaHCO3 and / or Na2CO3 powders), reaction products of alkaline powders with acidic pollutants (e.g., SO2, HCl, HF, etc.), and fly ash carried by the flue gas itself. The flue gas enters the filter bag from the outer surface of the filter bag 40, and the aforementioned dust-like substances (including unreacted alkaline powders, reaction products of alkaline powders with acidic pollutants, and fly ash carried by the flue gas itself) are trapped on the outer surface of the filter bag. The flue gas with the aforementioned dust-like substances removed (i.e., the filtered flue gas) is discharged from the inside of the conditioning bag through the flue gas outlet of the dust collector to the outside of the conditioning bag filter.

[0031] The conditioning bag filter 40 is a conventional bag filter in the art, generally comprising multiple filter bags; and a desulfurization ash silo is provided at the bottom of the bag filter. In an optional implementation, the fluidized bed reactor can refer to the usage described in relevant document CN101306311B, which can achieve the adsorption of sulfur oxides and other acidic gases and complete the acid-base neutralization reaction.

[0032] In this application, the flue gas treatment unit 20 in the dry purification system of the primary air of the sintering flue gas co-process waste heat utilization device can be used to collect and recycle desulfurizing agent and transport it to the fluidized bed reactor 30 as a desulfurization absorbent.

[0033] Optional, such as Figure 1 As shown, the flue gas treatment unit 20 may include a pre-electrostatic precipitator 21, a desulfurization reactor 22, and a bag filter 23 connected in sequence. The inlet of the pre-electrostatic precipitator 21 can be connected to the CFB boiler 10, and the bag filter 23 can be connected to the fluidized bed reactor 30 to transport the recycled desulfurizing agent into the fluidized bed reactor 30. In this case, after the flue gas from the CFB boiler 10 is precipitated by the pre-electrostatic precipitator 21, the recycled desulfurizing agent collected by the desulfurization reactor 22 and the bag filter 23 re-enters the primary air fluidized bed reactor 30 to complete desulfurization and acid gas removal, and then enters the primary air conditioning bag filter 40 to complete the flue gas dust conditioning and removal process. Since the flue gas volume after the CFB boiler 10 is larger, the recycled desulfurizing agent collected by the desulfurization reactor and the bag filter can meet the usage requirements.

[0034] Here, a pipe 24 can be installed between the bottom ash discharge port of the bag filter 23 and the fluidized bed reactor 30. An ash discharge pump (not shown in the figure) installed in the bag filter 23 can transport the recycled desulfurizing agent to the fluidized bed reactor 30 through the pipe 24. It should be noted that the bag filter 23 is typically equipped with an ash discharge port and an ash discharge pump. The ash discharge port connects to the pipe 24 and is connected to the fluidized bed reactor 30. The airflow generated by the ash discharge pump transports the recycled desulfurizing agent to the fluidized bed reactor 30 for reuse. It should also be noted that installing a pre-electrostatic precipitator 21 can intercept and remove most of the dust from the flue gas, thereby reducing the dust content in the recycled desulfurizing agent collected by the downstream bag filter 23 and improving its utilization rate.

[0035] In the embodiments of this application, such as Figure 1 As shown, the dry purification system of the primary air in the sintering flue gas co-processing waste heat utilization device is equipped with a first pipe 70 and a second pipe 80 connected to the sintering machine. One end of the first pipe 70 is connected to and communicates with the fluidized bed reactor 30, and the second pipe 80 is connected to the inlet of the secondary air fan 60. The outlet of the secondary air fan 60 is connected to the main combustion zone of the CFB boiler 10. The sintering flue gas from the sintering machine can be diverted through the first pipe 70 and the second pipe 80 respectively. In this case, by setting up two flue gas flow channels, the first pipe 70 can serve as the primary air flow channel, and the second pipe 80 can serve as the secondary air flow channel after the sintering flue gas is distributed. It should be noted that the outlet of the secondary air fan 60 and the main combustion zone of the CFB boiler 10 can be connected and in a connected state through a connecting pipe 90.

[0036] In this application, as Figure 1 As shown, a circulating fluidized bed reactor 30 can be provided between the conditioning bag filter 40 and the fluidized bed reactor 30. This circulating fluidized bed reactor 30 is used to recycle the ash from the ash hopper of the conditioning bag filter 40 back to the fluidized bed reactor 30. In this way, by providing the circulating fluidized bed reactor 30, the utilization rate of the desulfurizing agent is improved. Here, the conditioning bag filter 40 is also equipped with an ash discharge pump to guide the ash from the ash hopper of the conditioning bag filter 40 into the fluidized bed reactor 30 via airflow.

[0037] The process flow of the dry purification system for the primary air of the sintering flue gas co-processing waste heat utilization device is illustrated below: The flue gas from the main sintering outlet contains a certain amount of sulfur oxides, other acidic gases, and some alkaline earth metals and iron oxide dust. After being distributed through the flue, the flue gas from the main sintering outlet is divided into two paths: one path serves as primary air, entering the primary air fluidized bed reactor and the primary air conditioning bag filter to complete the flue gas conditioning treatment, and is then sent to the CFB boiler as primary air by the primary air fan, entering the primary air chamber and air cap inside the CFB boiler to provide the air volume required for the main combustion zone and fluidization; the other path serves as secondary air, directly sent to the CFB boiler by the secondary air fan, and then sent to the main combustion zone after passing through the secondary air nozzle to meet the air volume required for combustion and burnout. After exiting the CFB boiler, the high dust content flue gas first enters the pre-electrostatic precipitator to remove most of the particulate matter, and then enters the desulfurization reactor to complete the desulfurization reaction. Afterwards, the desulfurizing agent is collected and recycled by the bag filter, and finally, after desulfurization and dust removal, the flue gas is discharged.

[0038] Setting up a pre-electrostatic precipitator can intercept and remove most of the dust in the flue gas, thereby reducing the proportion of dust in the recycled desulfurizing agent collected by the downstream bag filter and improving its utilization rate.

[0039] The recycled desulfurizing agent collected by the bag filter is transported via pipeline to the primary fluidized bed reactor as a desulfurization absorbent. Inside the primary fluidized bed reactor, a large amount of desulfurizing agent is recycled and subjected to efficient turbulent flow, forming a high specific surface area alkaline particulate bed. This bed adsorbs sulfur oxides and other acidic gases, completing the acid-base neutralization reaction. The acidic gases in the flue gas are essentially completely desulfurized, significantly reducing the risk of corrosion in the primary air duct. Afterwards, the residual desulfurizing agent and flue gas dust are collected again by the primary air conditioning bag filter and recycled within the primary fluidized bed reactor. Meanwhile, the flue gas from the main exhaust outlet of the sintering process contains certain alkaline earth metals and iron oxide dust. After particulate matter encapsulation reaction and dust removal and conditioning, the flue gas entering the primary air fan meets the fluidization requirements of the CFB boiler. After conditioning and dust removal, the dust content in the flue gas is greatly reduced, and the alkaline earth metals and iron oxide components in the dust that easily cause coking and blockage of the boiler air cap are greatly reduced, thus achieving the conditioning process.

[0040] Please refer to Figure 2 , Figure 2 This is a schematic flowchart of a dry purification method for primary air in a sintering flue gas co-processing waste heat utilization device, provided in an embodiment of this application. This application also provides a dry purification method for primary air in a sintering flue gas co-processing waste heat utilization device. This dry purification method for primary air in a sintering flue gas co-processing waste heat utilization device can be applied to any of the dry purification systems for primary air in sintering flue gas co-processing waste heat utilization devices given above. The method may include: One stream of sintering flue gas is introduced into a fluidized bed reactor to adsorb sulfur oxides and other acidic gases and complete the acid-base neutralization reaction; The flue gas that has completed the acid-base neutralization reaction is introduced into a conditioning bag filter for dust removal; The primary air after dust removal is introduced into the furnace of the CFB boiler from the bottom through a primary air fan.

[0041] In summary, this application provides a dry purification method for primary air of a sintering flue gas co-processing waste heat utilization device. A dry purification system is set up before the sintering flue gas enters the primary air fan of the CFB boiler. The system includes a circulating fluidized bed reactor and a conditioning bag filter. The circulating fluidized bed reactor uses thousands of times the amount of circulating material to encapsulate the alkaline earth metals and iron oxide dust in the sintering flue gas. The dust is then removed by the conditioning bag filter. Sulfur oxides in the flue gas can be removed. The purified sintering flue gas enters the CFB boiler as primary air, eliminating the problems of coking and blockage of the primary air cap and corrosion of the primary air duct. This ensures the stable and reliable operation of the CFB boiler and the entire system.

[0042] In this application, after the flue gas treatment unit desulfurizes and removes dust from the flue gas discharged from the CFB boiler, the dry purification method of the primary air of the sintering flue gas combined with the waste heat utilization device may further include: the flue gas treatment unit collects and recycles the desulfurizing agent and transports it to the fluidized bed reactor as a desulfurization absorbent.

[0043] In this embodiment of the application, when the flue gas treatment unit includes a pre-electrostatic precipitator, a desulfurization reactor, and a bag filter connected in sequence, the step of the flue gas treatment unit collecting and recycling desulfurizing agent and conveying it to the fluidized bed reactor as a desulfurization absorbent may include: connecting the bag filter to the fluidized bed reactor to convey the recycled desulfurizing agent in the ash hopper of the bag filter to the fluidized bed reactor.

[0044] Optionally, the dry purification method for the primary air of the sintering flue gas co-processing waste heat utilization device may also include: introducing the ash from the ash hopper of the conditioning bag filter into the fluidized bed reactor.

[0045] Here, a pipe is installed between the bottom ash discharge port of the bag filter and the fluidized bed reactor. The ash discharge pump installed in the bag filter can transport the recycled desulfurizing agent to the fluidized bed reactor through the pipe.

[0046] The embodiments of the dry purification system for primary air of the sintering flue gas co-process waste heat utilization device and the dry purification method for primary air of the sintering flue gas co-process waste heat utilization device provided in this invention can be referred to each other, and the embodiments of this invention will not be described again here.

[0047] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0048] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dry purification system for primary air of a sintering flue gas co-processing waste heat utilization device, characterized in that, It is equipped with two flue gas circulation channels, a CFB boiler, and a flue gas treatment unit; One of the flue gas flow channels is equipped with a fluidized bed reactor, a conditioning bag filter, and a primary air fan connected in sequence. The primary air in the flue gas flow channel is used to adsorb sulfur oxides and other acidic gases and complete the acid-base neutralization reaction in the fluidized bed reactor; dust removal is performed in the conditioning bag filter; and the primary air fan is used to introduce the treated primary air from the bottom of the CFB boiler into the furnace of the CFB boiler. A secondary air fan is installed on the other flue gas circulation channel, and the secondary air fan is used to introduce secondary air into the main combustion zone of the CFB boiler; The flue gas treatment unit is used to desulfurize and remove dust from the flue gas discharged from the CFB boiler before discharging it.

2. The dry purification system for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 1, characterized in that, The flue gas treatment unit is used to collect and recycle the desulfurizing agent and transport it to the fluidized bed reactor as a desulfurization absorbent.

3. The dry purification system for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 2, characterized in that, The flue gas treatment unit includes a pre-electrostatic precipitator, a desulfurization reactor, and a bag filter connected in sequence. The inlet of the pre-electrostatic precipitator is connected to the CFB boiler, and the bag filter is connected to the fluidized bed reactor to transport the recycled desulfurizing agent into the fluidized bed reactor.

4. The dry purification system for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 3, characterized in that, A pipe is provided between the bottom ash discharge port of the bag filter and the fluidized bed reactor. The ash discharge pump installed in the bag filter transports the recycled desulfurizing agent to the fluidized bed reactor through the pipe.

5. The dry purification system for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 1, characterized in that, The dry purification system of the primary air of the sintering flue gas co-process waste heat utilization device is provided with a first pipe and a second pipe connected to the sintering machine. One end of the first pipe is connected to the fluidized bed reactor, and the second pipe is connected to the secondary air fan and the CFB boiler. The sintering flue gas from the sintering machine is diverted through the first pipe and the second pipe, respectively.

6. The dry purification system for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 1, characterized in that, A circulating fluidized bed reactor is provided between the conditioning bag filter and the fluidized bed reactor. The circulating fluidized bed reactor is used to recycle the ash from the ash hopper in the conditioning bag filter back to the fluidized bed reactor.

7. A dry purification method for primary air in a sintering flue gas co-processing waste heat utilization device, characterized in that, The method is applied to the dry purification system of the primary air of the sintering flue gas co-processing waste heat utilization device according to any one of claims 1-6, and the method includes: One stream of sintering flue gas is introduced into a fluidized bed reactor to adsorb sulfur oxides and other acidic gases and complete the acid-base neutralization reaction; The flue gas that has completed the acid-base neutralization reaction is introduced into a conditioning bag filter for dust removal; The primary air after dust removal is introduced into the furnace of the CFB boiler from the bottom through a primary air fan.

8. The dry purification method for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 7, characterized in that, After the flue gas treatment unit desulfurizes and removes dust from the flue gas discharged from the CFB boiler, the method further includes: the flue gas treatment unit collects and recycles the desulfurizing agent and transports it to the fluidized bed reactor as a desulfurization absorbent.

9. The dry purification method for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 8, characterized in that, In the case where the flue gas treatment unit includes a pre-electrostatic precipitator, a desulfurization reactor, and a bag filter connected in sequence, the step of the flue gas treatment unit collecting and recycling desulfurizing agent and conveying it to the fluidized bed reactor as a desulfurization absorbent includes: the bag filter is connected to the fluidized bed reactor to convey the recycled desulfurizing agent in the ash hopper of the bag filter to the fluidized bed reactor.

10. The dry purification method for primary air of the sintering flue gas co-processing waste heat utilization device according to claim 7, the method further comprising: The ash in the ash hopper of the conditioning bag filter is circulated into the fluidized bed reactor.

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