A sintering machine head flue bag dust removal system and method

Abstract

The application discloses a sintering machine head flue bag type dust removal system and method, which comprises a sintering device and sequentially arranged flue gas pretreatment device, flue gas treatment heat recycling device, bag type dust removal mechanism and desulfurization and emission device along the airflow direction. The sintering device comprises a sintering machine, a large flue, a head air bellow mechanism arranged near the head of the sintering machine and a middle-tail air bellow mechanism downstream of the head air bellow mechanism. The middle-tail air bellow mechanism comprises a plurality of sequentially arranged exhaust units and air bellow on-off control valves corresponding to the exhaust units. The exhaust units are used for connecting the sintering machine and the large flue. The flue gas pretreatment device, the flue gas treatment heat recycling device, the bag type dust removal mechanism and the desulfurization and emission device are sequentially arranged downstream of the large flue. The sintering machine head flue bag type dust removal system and method avoid the problems of large sintering flue gas temperature fluctuation and influence on the dust removal efficiency of the bag type dust remover, and avoid low-temperature corrosion of the dust removal bag of the bag type dust removal mechanism.

Description

Technical Field

[0001] This invention relates to the field of sintering machine technology, and in particular, to a bag-type dust collection system and method for sintering machine head flue gas. Background Technology

[0002] Sintering is a fundamental step in the steel industry, providing high-quality raw materials for ironmaking. The sintering process involves batching, mixing, granulating, and then feeding the iron-containing raw materials onto a sintering trolley. Finally, during the uniform operation of the sintering machine, the materials are roasted at high temperatures (≤1400℃) by the action of ventilation, causing a series of physicochemical changes in the materials. After crushing, the materials are transformed into porous, blocky sintered ore with a certain strength.

[0003] Sintering, as a major process in ironmaking, accounts for 20% of the total pollutant emissions from the steel industry. Sintering machine flue gas is characterized by large volume, high temperature, high corrosiveness, easy condensation, high negative pressure, and fluctuating operating conditions, making it difficult to treat. Traditionally, electrostatic precipitators (ESPs) have been used for flue gas purification both domestically and internationally. However, due to their unstable dust removal efficiency, the outlet particulate matter concentration exceeds the standard (ranging from 50 mg / m³ to 150 mg / m³), seriously affecting the stable compliance of subsequent desulfurization and denitrification systems. This has become a bottleneck problem restricting ultra-low emissions from the sintering process and urgently needs to be solved. Baghouse filters can efficiently remove fine particulate matter, with an outlet particulate matter concentration of <10 mg / m³. Using baghouse filters to purify sintering machine flue gas can achieve stable ultra-low emissions.

[0004] Based on baghouse dust collection for flue gas treatment, how to ensure the stable operation of the baghouse dust collection system for sintering machine head flue gas is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The sintering machine head flue gas bag dust collection system and method provided by the present invention solves the technical problem of unstable operation of existing sintering machine head flue gas bag dust collection systems.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A sintering machine head flue gas bag filter system includes a sintering device and a flue gas pretreatment device, a flue gas treatment heat recovery and utilization device, a bag filter mechanism, and a desulfurization emission device arranged sequentially along the airflow direction. The sintering device includes a sintering machine, a main flue, a head bellows mechanism arranged near the head of the sintering machine, and a middle and tail bellows mechanism located downstream of the head bellows mechanism. The middle and tail bellows mechanism includes multiple exhaust units arranged sequentially and bellows on / off control valves arranged one-to-one with the exhaust units. The exhaust units are used to connect the sintering machine and the main flue. The flue gas pretreatment device, the flue gas treatment heat recovery and utilization device, the bag filter mechanism, and the desulfurization emission device are sequentially arranged downstream of the main flue.

[0008] Furthermore, the flue gas pretreatment device includes an inlet pipe, an exhaust pipe, a rotating cone, an ash collection trough, and a dust collector cylinder with a hollow cavity. The inlet pipe and the exhaust pipe are both located on the dust collector cylinder and are connected to the hollow cavity respectively. The exhaust pipe is located above the inlet pipe. The dust collector cylinder covers the rotating cone. The rotating cone is rotatably arranged around the central axis of the dust collector cylinder. The rotating cone is arranged vertically and the large-diameter end of the rotating cone is located close to the rotating drive mechanism. A spiral guide groove is recessed on the outer circumference of the rotating cone. The outlet end of the inlet pipe is connected to the outlet end of the main flue.

[0009] Furthermore, fire extinguishing protrusions are provided on the outer circumferential wall of the rotating cone, and the fire extinguishing protrusions are staggered with the spiral guide groove.

[0010] Furthermore, the sintering machine head flue gas bag dust removal system also includes a PLC controller, and the middle and tail air box mechanism also includes position sensors that are arranged one-to-one with the exhaust unit. The position sensors, air box on / off control valves and PLC controller are electrically connected.

[0011] Furthermore, the flue gas treatment heat recovery and utilization device includes a combustion mechanism and a mixing and denitrification reaction mechanism arranged sequentially along the airflow direction. The combustion mechanism includes a combustion reaction chamber, a burner, and a gas pipe. The burner is located in the combustion reaction chamber, and the gas pipe is located on the combustion reaction chamber. The mixing and denitrification reaction mechanism includes a mixing chamber and an SCR denitrification reaction chamber arranged sequentially. An ammonia inlet pipe is provided on the mixing chamber. The first end of the mixing chamber is connected to the outlet of the combustion reaction chamber, and the second end of the mixing chamber is connected to the inlet of the SCR denitrification reaction chamber. The inlet of the combustion reaction chamber is connected to the outlet pipe.

[0012] Furthermore, a waste heat boiler is also installed between the SCR denitrification reaction chamber and the bag filter dust collection mechanism.

[0013] Furthermore, the desulfurization emission device includes a desulfurization chamber, an exhaust fan, and a chimney arranged sequentially along the airflow direction.

[0014] This invention also provides a baghouse dust collection method for sintering machine head flue gas, used in the aforementioned baghouse dust collection system for sintering machine head flue gas, comprising the following steps: during the start-up process of the sintering system, the head air box mechanism is pre-opened to provide reaction conditions for ignition operation; during the process of the initial sintering trolley moving to the end air box after loading and ignition, the current position information of the first initial sintering trolley is obtained, and before the initial sintering trolley reaches the position of the next exhaust air box, the air box on / off control valve downstream of the initial sintering trolley is pre-opened; the flue gas pretreatment device receives the initial flue gas discharged from the main flue, filters the large particulate dust in the initial flue gas, and discharges the secondary flue gas to the flue gas treatment heat recovery and utilization device; the flue gas treatment heat recovery and utilization device receives the secondary flue gas and burns the secondary flue gas to raise its temperature, then performs mixing and denitrification treatment, and outputs tertiary flue gas; the baghouse dust collection mechanism further filters the tertiary flue gas and discharges it after treatment by the desulfurization emission device.

[0015] Furthermore, during the shutdown process of the sintering system, when the end sintering trolley moves to the top of the tail section wind box mechanism after loading and ignition, the head wind box mechanism is closed; during the process of the end sintering trolley moving to the end wind box after loading and ignition, the current position information of the end sintering trolley is obtained. After the end sintering trolley leaves the position of the previous exhaust wind box, the wind box on / off control valve upstream of the end sintering trolley is closed, or, when the temperature obtained by the temperature sensor upstream of the end sintering trolley reaches the preset low temperature threshold, the corresponding wind box on / off control valve is closed; the flue gas pretreatment device receives the initial flue gas discharged from the main flue, filters and initially extinguishes the large particulate dust in the initial flue gas, and then discharges the secondary flue gas to the flue gas treatment heat recovery and utilization device; the flue gas treatment heat recovery and utilization device receives the secondary flue gas, further extinguishes the sparks by combustion, and then performs mixing and denitrification treatment to output the tertiary flue gas; the bag filter further filters the tertiary flue gas and discharges it after treatment by the desulfurization emission device.

[0016] Furthermore, during continuous operation of the sintering system, the head bellows mechanism is in the open state, and all bellows on / off control valves are in the open state. The flue gas pretreatment device receives the initial flue gas discharged from the main flue and filters the large particulate dust in the initial flue gas before discharging the secondary flue gas to the flue gas treatment heat recovery and utilization device. The flue gas treatment heat recovery and utilization device receives the secondary flue gas and burns it to raise its temperature. After mixing and denitrification treatment, it outputs tertiary flue gas. The bag filter further filters the tertiary flue gas and discharges it after treatment by the desulfurization emission device. When the sintering system is under maintenance, the head bellows mechanism is in the closed state, and all bellows on / off control valves are in the closed state. The combustion mechanism receives blast furnace gas and burns it to generate effective flue gas. The effective flue gas enters the bag filter and is discharged through the chimney to prevent the bag filter from condensing and corroding at low temperatures.

[0017] The present invention has the following beneficial effects:

[0018] The sintering machine head flue gas bag filter dust collection system of the present invention includes a sintering device, a flue gas pretreatment device, a flue gas treatment heat recovery and utilization device, a bag filter dust collection mechanism, and a desulfurization emission device. By treating the sintering machine head flue gas through the bag filter dust collector, stable ultra-low emissions of the sintering machine head flue gas can be achieved. The sintering device includes a sintering machine, a main flue, a head wind box mechanism arranged near the head of the sintering machine, and a middle and tail wind box mechanism located downstream of the head wind box mechanism. The middle and tail wind box mechanism includes multiple exhaust units arranged sequentially and a pair of exhaust units. The installed air box on / off control valves should, when the sintering system is in startup, open the downstream air box control valve adjacent to the initial sintering trolley based on the movement position of the initial sintering trolley or the air box temperature. This effectively prevents excessive cold air from being drawn into the main flue from above the empty sintering trolley during startup, reducing the flow of cold air into the main flue during the startup phase. This facilitates adjustment of the flue gas temperature during startup, helps regulate the temperature fluctuation range of the sintering flue gas, and avoids large temperature fluctuations that could affect the dust removal function of the bag filter. Regarding efficiency, when the sintering system is in a closed state, the upstream air box control valve adjacent to the end sintering trolley can be closed according to the movement position of the end sintering trolley or the air box temperature. This effectively prevents too much cold air from being drawn into the main flue from above the empty sintering trolley during the shutdown process of the sintering system, reduces the flow of cold air into the main flue during the shutdown phase of the sintering system, facilitates the adjustment of the flue gas temperature during the shutdown phase, and helps to adjust the temperature range of the sintering flue gas, avoiding large fluctuations in the sintering flue gas temperature that affect the dust removal efficiency of the bag filter. When the sintering system is in continuous operation, all air box on / off control valves are opened to ensure the normal operation of the sintering system. When the sintering system is under maintenance, all air box on / off control valves are closed to prevent flue gas flow at the sintering machine location. At the same time, high-temperature flue gas is supplied to the bag filter mechanism through the flue gas treatment heat recovery and utilization device, which helps to adjust the temperature range of the sintering flue gas and avoid large temperature fluctuations in the sintering flue gas, which would affect the dust removal efficiency of the bag filter and prevent low-temperature corrosion of the filter bags in the bag filter mechanism.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 This is one of the structural schematic diagrams of a bag filter system for sintering machine head flue gas in one embodiment of the present invention;

[0022] Figure 2 This is a second schematic diagram of the structure of the sintering machine head flue gas bag dust removal system in one embodiment of the present invention;

[0023] Figure 3 yes Figure 2 A schematic diagram of the sintering machine head flue gas pretreatment device;

[0024] Figure 4 yes Figure 3 A schematic diagram of the rotating cone in the diagram.

[0025] Explanation of icon numbers:

[0026] 100. Sintering machine head flue gas bag filter system; 10. Sintering device; 11. Sintering machine; 12. Main flue; 13. Head bellows mechanism; 14. Middle and tail bellows mechanism; 141. Exhaust unit; 142. Bellows on / off control valve; 143. Temperature sensor; 20. Flue gas pretreatment device; 21. Inlet pipe; 22. Exhaust pipe; 23. Rotating cone; 24. Ash collection trough; 25. Dust collector cylinder; 251. Hollow cavity; 26. Fire extinguishing protrusion; 27. Reflection mechanism; 271. Air hole; 30. Flue gas treatment heat recovery and utilization device; 31. Combustion mechanism; 32. Mixing and denitrification reaction mechanism; 40. Bag filter mechanism; 50. Desulfurization emission device; 51. Desulfurization chamber; 52. Exhaust fan; 53. Chimney. Detailed Implementation

[0027] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0030] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0031] Please refer to Figure 1 In the existing sintering machine head flue gas bag filter system, the flue gas in the sintering machine's air box is collected into the main flue by the action of the exhaust fan, and then passes through the bag filter for dust removal, the flue gas desulfurization device for desulfurization, and the flue gas denitrification device for denitrification before being discharged through the chimney.

[0032] Research revealed the following technical problems with existing baghouse dust collection systems for sintering machine flue gas: First, the filter bags are easily burned through by sparks in the flue gas when using existing baghouse dust collectors for sintering flue gas dust collection. Second, large temperature fluctuations in the sintering flue gas affect the dust collection efficiency of the baghouse dust collector; specifically, excessively high flue gas temperatures can easily cause filter bag ignition, while excessively low flue gas temperatures can lead to low-temperature corrosion of the filter bags due to condensation of acidic gases. Third, the existing baghouse dust collection systems for sintering flue gas do not fully utilize the waste heat in the flue gas. Fourth, the existing sintering flue gas bag filter system has unburned coal gas and coal powder in the flue gas during the production process. Coal gas and coal powder are prone to explosion in the bag filter, resulting in poor safety and stability. Fifth, when the sintering machine is started up in a cold state, the temperature of the sintering flue gas is low and unstable. Acidic gases are prone to condensation and corrosion of the filter bags, and the dust removal efficiency of the bag filter is low. Sixth, the filter bags of the existing sintering flue gas bag filter are easily worn by large particles of dust in the flue gas (especially iron ore powder and return ore particles with high hardness and large particle size), resulting in a short service life.

[0033] like Figure 2 , Figure 3 and Figure 4As shown, the present invention provides a sintering machine head flue gas bag filter system 100, including a sintering device 10 and a flue gas pretreatment device 20, a flue gas treatment heat recovery and utilization device 30, a bag filter mechanism 40, and a desulfurization emission device 50 arranged sequentially along the airflow direction. The sintering device 10 includes a sintering machine 11, a main flue 12, a head bellows mechanism 13 arranged near the head of the sintering machine 11, and a middle and tail bellows mechanism 14 located downstream of the head bellows mechanism 13. The middle and tail bellows mechanism 14 includes a plurality of exhaust units 141 arranged sequentially and bellows on / off control valves 142 arranged one-to-one with the exhaust units 141. The exhaust units 141 are used to connect the sintering machine 11 and the main flue 12. The flue gas pretreatment device 20, the flue gas treatment heat recovery and utilization device 30, the bag filter mechanism 40, and the desulfurization emission device 50 are sequentially arranged downstream of the main flue 12.

[0034] The sintering machine head flue gas bag filter system 100 of the present invention includes a sintering device 10, a flue gas pretreatment device 20, a flue gas treatment heat recovery and utilization device 30, a bag filter mechanism 40, and a desulfurization emission device 50. By treating the flue gas from the sintering machine head 11 through the bag filter, stable ultra-low emissions of the flue gas from the sintering machine head 11 can be achieved. The sintering device 10 includes a sintering machine 11, a main flue 12, a head bellows mechanism 13 arranged near the head of the sintering machine 11, and a mid-tail bellows mechanism 14 located downstream of the head bellows mechanism 13. The mid-tail bellows mechanism 14 includes... Multiple exhaust units 141 arranged sequentially and corresponding air box on / off control valves 142 are arranged one-to-one with each exhaust unit 141. When the sintering system is in the start-up state, the downstream air box on / off control valves 142 adjacent to the initial sintering trolley can be opened according to the movement position of the initial sintering trolley or the air box temperature. This effectively prevents too much cold air from being drawn into the main flue 12 from above the empty trolley of the sintering machine 11 during the start-up process, reduces the flow of cold air into the main flue 12 during the start-up phase of the sintering system, facilitates the adjustment of the flue gas temperature during the start-up phase, and helps to adjust the temperature range of the sintering flue gas, avoiding... The large temperature fluctuations in sintering flue gas affect the dust removal efficiency of baghouse dust collectors. When the sintering system is shut down, the upstream air box on / off control valve 142, located adjacent to the end sintering trolley, can be closed based on the movement of the end sintering trolley or the air box temperature. This effectively prevents excessive cold air from being drawn into the main flue 12 from above the empty trolley of the sintering machine 11 during the shutdown process, reducing the flow of cold air into the main flue 12 during the shutdown phase. This facilitates adjustment of the flue gas temperature during shutdown, helps regulate the temperature fluctuation range of the sintering flue gas, and avoids large temperature fluctuations that could affect the dust removal efficiency of the baghouse dust collector. Regarding dust collection efficiency, when the sintering system is in continuous operation, all air box on / off control valves 142 are opened to ensure the normal operation of the sintering system. When the sintering system is under maintenance, all air box on / off control valves 142 are closed to prevent flue gas flow at the sintering machine 11. At the same time, high-temperature flue gas is supplied to the bag filter dust collection mechanism 40 through the flue gas treatment heat recovery and utilization device 30, which helps to adjust the temperature range of the sintering flue gas and avoid large temperature fluctuations in the sintering flue gas, which would affect the dust collection efficiency of the bag filter and prevent low-temperature corrosion of the dust collection bags in the bag filter dust collection mechanism 40.

[0035] Understandably, the head bellows mechanism 13 includes bellows and pipes located below and upstream of the electric furnace. The head bellows mechanism is equipped with control valves for opening and closing. When the head bellows mechanism is open, flue gas is discharged into the main flue; when the head bellows mechanism is closed, flue gas is not discharged into the main flue. Specifically, the head bellows mechanism includes four sets of bellows, with the bellows, pipes, and control valves arranged correspondingly. The exhaust unit 141 includes exhaust bellows and bellows pipes. The mid-to-tail bellows mechanism 14 includes multiple exhaust bellows, bellows pipes, and bellows on / off control valves 142 located downstream of the electric furnace. The sintering machine 11 and the main flue 12 are connected through the head bellows mechanism 13 and the tail bellows mechanism. Optionally, the bellows on / off control valves 142 can be located on the exhaust bellows or on the bellows pipes.

[0036] Understandably, the flue gas pretreatment device 20 is used to receive the initial flue gas discharged from the main flue 12, and after filtering and extinguishing the large particulate dust in the initial flue gas, it discharges the secondary flue gas to the flue gas treatment heat recovery and utilization device 30; the flue gas treatment heat recovery and utilization device 30 receives the secondary flue gas and burns it to raise the temperature of the secondary flue gas and extinguish the sparks, and then performs mixing and denitrification treatment to output the tertiary flue gas; the bag filter dust collector 40 further filters the tertiary flue gas and treats it through the desulfurization emission device 50 before discharging it to the outside.

[0037] Optionally, the temperature sensor is placed on the corresponding bellows.

[0038] Understandably, the flue gas pretreatment device 20, the flue gas treatment heat recovery and utilization device 30, the bag filter dust collector 40, and the desulfurization emission device 50 are connected by pipelines.

[0039] In specific implementation, the mid-tail bellows mechanism 14 includes exhaust bellows and bellows pipes arranged in a one-to-one correspondence. Multiple exhaust bellows are arranged sequentially on the sintering machine 11. The bellows pipe is equipped with a bellows on / off control valve 142. The input end of the bellows pipe is connected to the corresponding exhaust bellows, and the output end of the bellows pipe is connected to the main flue 12. The flue gas pretreatment device 20, the flue gas treatment heat recovery and utilization device 30, the bag filter dust removal mechanism 40, and the desulfurization emission device 50 are sequentially arranged downstream of the main flue 12.

[0040] Please refer to Figure 3 and Figure 4Furthermore, the flue gas pretreatment device 20 includes an inlet pipe 21, an exhaust pipe 22, a rotating cone 23, a dust collection trough 24, and a dust collector cylinder 25 with a hollow cavity 251. The inlet pipe 21 and the exhaust pipe 22 are both located on the dust collector cylinder 25 and are respectively connected to the hollow cavity 251. The exhaust pipe 22 is located above the inlet pipe 21. The dust collector cylinder 25 covers the rotating cone 23. The rotating cone 23 is rotatably arranged around the central axis of the dust collector cylinder 25. The rotating cone 23 is arranged vertically and its large-diameter end is located close to the rotating drive mechanism. A spiral guide groove is recessed on the outer circumferential wall of the rotating cone 23. The outlet end of the inlet pipe 21 is connected to the outlet end of the large flue 12.

[0041] In specific implementation, the flue gas pretreatment device 20 includes an inlet pipe 21, an exhaust pipe 22, a rotating cone 23, a support frame, a dust collection trough 24, and a dust collector cylinder 25 with a hollow cavity 251. The inlet pipe 21 and the exhaust pipe 22 are both located on the dust collector cylinder 25 and are respectively connected to the hollow cavity 251. The exhaust pipe 22 is located above the inlet pipe 21. The dust collector cylinder 25 covers the rotating cone 23. The support frame is located at the bottom opening of the dust collector cylinder 25. The rotating drive mechanism is located on the support frame and is used to drive the rotating cone 23 to rotate around the central axis of the dust collector cylinder 25. The rotating cone 23 is arranged vertically and the large diameter end of the rotating cone 23 is located close to the rotating drive mechanism. A spiral guide groove is recessed on the outer circumferential wall of the rotating cone 23. The outlet end of the inlet pipe 21 is connected to the large flue 12. Optionally, the rotary drive mechanism can be a rotary drive motor, and the dust collection trough 24 can be a dust collection hopper, with a discharge valve at the bottom of the hopper. In this invention, the dust collection trough 24 is used to cover the bottom opening, thereby receiving dust falling from the hollow cavity 251; large dust particles slide down from the side of the rotating cone 23 into the dust collection trough 24. Optionally, the spiral guide channel is an upward spiral channel, mounted on the bottom opening of the dust collector cylinder 25, and the rotating cone 23 is mounted on the mounting bracket.

[0042] By setting up a pre-treatment device 20 for the flue gas from the sintering machine 11, the flue gas from the machine head is introduced into the dust collector frame through the air inlet pipe 21. The rotating drive mechanism, mounted on the mounting frame, drives the rotating cone 23 to rotate within the hollow cavity 251. When the flue gas from the machine head impacts the rotating cone 23 under the guidance of the air inlet pipe 21, large dust particles (mainly iron ore powder and return ore) in the flue gas impact the surface of the rotating cone 23 and fall directly into the dust collection trough 24. The rotating drive mechanism drives the rotating cone 23 to rotate, and under the action of the spiral guide groove, an upward vortex force is generated in the hollow cavity 251, causing the flue gas from the machine head to form a vortex, which is beneficial for mixing the flue gas from the machine head. The filtered flue gas from the machine head is discharged through the exhaust pipe 22, thus achieving preliminary purification treatment of the flue gas from the machine head. This solves the technical problem that the existing flue gas from the machine head is directly discharged into the dust collector bag, and the large dust particles in the flue gas easily accelerate the wear of the dust collector bag.

[0043] Optionally, in order to further reduce the workload of the bag filter, the rotating cone 23, the dust filter hood, the dust collection trough 24 and the dust collection cylinder 25 are arranged coaxially, the rotating drive mechanism is mounted on the mounting frame, and the first discharge port is located on the top surface of the dust collection cylinder 25 and is arranged coaxially with the dust collection cylinder 25.

[0044] Furthermore, the flue gas pretreatment device 20 also includes a reflection mechanism 27 disposed above the rotating cone 23. The reflection mechanism 27 includes a reflector plate, and the reflector plate is provided with air holes 271 penetrating the surface of the reflector plate. Optionally, the air holes 271 are inverted frustum-shaped holes that gradually narrow downwards along the vertical direction. There are multiple reflector plates, which are arranged at intervals along the vertical direction, and the air holes 271 of adjacent vertical reflector plates are staggered in the horizontal direction. In actual operation, under the action of the rotating cone 23, the flue gas rises and passes through the air holes 271 before being discharged through the exhaust pipe 22. The reflection mechanism 27 further blocks and filters the rising and discharged flue gas, further preventing large particles of dust in the flue gas from being discharged into the dust collector bag.

[0045] Furthermore, a fire extinguishing protrusion 26 is provided on the outer circumferential wall of the rotating cone 23, and the fire extinguishing protrusion 26 is staggered with the spiral guide groove. Understandably, the fire extinguishing protrusion 26 is triangular or quadrilateral in shape. More preferably, to facilitate the falling of large dust particles, the outer wall of the fire extinguishing protrusion 26 is a downward-sloping surface, allowing large dust particles to fall along the inclined surface into the ash collection trough 24. By providing the fire extinguishing protrusion 26, large dust particles (mainly iron ore powder and return ore) in the flue gas impact the fire extinguishing protrusion 26 and fall into the ash collection trough 24, while sparks in the flue gas impact the fire extinguishing protrusion 26 and are extinguished.

[0046] Furthermore, the sintering machine head flue gas bag filter system 100 also includes a PLC controller, and the mid-to-tail air box mechanism 14 also includes temperature sensors and / or position sensors arranged one-to-one with the exhaust unit 141. The temperature sensors and / or position sensors, the air box on / off control valve 142, and the PLC controller are electrically connected. By setting temperature sensors and / or position sensors and a PLC controller, it is convenient to pre-open the air box pipe downstream of the initial sintering trolley when the sintering system is in the start-up state, and to close the air box pipe upstream of the end sintering trolley when the sintering system is in the shutdown state. This not only helps to reduce energy loss, but also reduces flue gas fluctuations through the bag filter mechanism 40.

[0047] Furthermore, the flue gas treatment heat recovery and utilization device 30 includes a combustion mechanism 31 and a mixing and denitrification reaction mechanism 32 arranged sequentially along the airflow direction. The combustion mechanism 31 includes a combustion reaction chamber, a burner, and a gas pipe. The burner is located in the combustion reaction chamber, and the gas pipe is located on the combustion reaction chamber. The mixing and denitrification reaction mechanism 32 includes a mixing chamber and an SCR denitrification reaction chamber arranged sequentially. An ammonia inlet pipe is provided on the mixing chamber. The first end of the mixing chamber is connected to the outlet of the combustion reaction chamber, and the second end of the mixing chamber is connected to the inlet of the SCR denitrification reaction chamber. The inlet of the combustion reaction chamber is connected to the outlet pipe.

[0048] Furthermore, a waste heat boiler is also provided between the SCR denitrification reaction chamber and the bag filter dust removal mechanism 40.

[0049] Furthermore, the desulfurization emission device 50 includes a desulfurization chamber 51, an exhaust fan 52, and a chimney 53 arranged sequentially along the airflow direction.

[0050] Understandably, the gas supplied through the gas pipe is preferably low-calorific-value gas such as surplus blast furnace gas or converter gas from steel enterprises. The combustion of low-calorific-value gas can remove sparks from the flue gas, and the combustion temperature will not be too high to form nitrogen oxides. The initial flue gas entering the combustion chamber can effectively remove sparks and residual gas. Designing the combustion chamber to remove sparks and residual gas from the initial flue gas is one of the further innovations of this invention. This is because during the sintering process, the sintering mixture is sintered from top to bottom under the action of ventilation. The carbon in the material layer may not be completely burned after ignition before entering the flue under the action of ventilation. Because the blast furnace gas inside has a low calorific value and a large surplus, much of it is directly released into the air. The low-calorific-value surplus blast furnace gas is used to remove sparks from the high-temperature flue gas at the tail of sintering machine 11, ensuring that the sparks are fully burned in the combustion chamber. At the same time, the above design can also be linked to the SCR denitrification reaction. The reason why it is difficult and costly to carry out SCR operation on existing sintering flue gas is that the sintering flue gas cannot reach the temperature of the SCR denitrification reaction (280-420℃). After the flue gas in the tail wind box of sintering machine 11 is desparked in the combustion chamber, it can be heated up to carry out the subsequent SCR denitrification reaction. In actual operation, the flue gas after being de-ignited and purified by the combustion chamber is transported to the mixing chamber through a pipeline. The mixing chamber 15 is connected to an ammonia inlet pipe. The flue gas in the mixing chamber is then transported to the SCR denitrification reaction chamber through a pipeline. After mixing, the flue gas passes through the SCR denitrification reaction chamber to remove nitrogen oxides. Then, it is connected to the waste heat boiler through a pipeline to recover the waste heat in the flue gas. After the waste heat in the flue gas is recovered, it can enter the bag filter of the bag dust collector 40 under the action of the exhaust fan 52 for dust removal, and then enter the desulfurization device for desulfurization. The desulfurized flue gas is directly discharged into the atmosphere through the chimney 53.

[0051] The present invention also provides a method for baghouse dust collection of flue gas from 11 sintering machine heads, used in the aforementioned baghouse dust collection system 100 for sintering machine heads, comprising the following steps:

[0052] During the start-up of the sintering system, the head bellows mechanism is pre-activated to provide reaction conditions for ignition. As the initial sintering trolley moves to the end bellows after loading and ignition, the current position information of the leading initial sintering trolley is obtained. Before the initial sintering trolley reaches the next exhaust bellows, the bellows on / off control valve 142 downstream of the initial sintering trolley is pre-activated. Alternatively, when the temperature obtained by the temperature sensor reaches a preset high-temperature threshold, the corresponding bellows on / off control valve 142 is activated. The flue gas pretreatment device 20 receives the initial flue gas discharged from the main flue duct 12 and filters the large particulate dust in the initial flue gas before discharging secondary flue gas into the flue gas treatment heat recovery and utilization device 30. The flue gas treatment heat recovery and utilization device 30 receives the secondary flue gas and burns it to raise its temperature. After mixing and denitrification, it outputs tertiary flue gas. The bag filter dust collector 40 further filters the tertiary flue gas and discharges it after treatment by the desulfurization emission device 50.

[0053] Furthermore, during the shutdown process of the sintering system, when the end sintering trolley moves to the top of the middle and rear air box mechanism after loading and ignition, the head air box mechanism is closed; during the process of the end sintering trolley moving to the end air box after loading and ignition, the current position information of the end sintering trolley is obtained. After the end sintering trolley leaves the position of the previous exhaust air box, the air box on / off control valve 142 upstream of the end sintering trolley is closed, or the temperature obtained by the temperature sensor upstream of the end sintering trolley reaches the preset low temperature threshold. When the value is reached, the corresponding air box on / off control valve 142 is closed. The flue gas pretreatment device 20 receives the initial flue gas discharged from the main flue duct 12, filters the large particulate dust in the initial flue gas and extinguishes the sparks, and then discharges the secondary flue gas to the flue gas treatment heat recovery and utilization device 30. The flue gas treatment heat recovery and utilization device 30 receives the secondary flue gas and further extinguishes the sparks by combustion, and then performs mixing and denitrification treatment to output the tertiary flue gas. The bag filter dust collector 40 further filters the tertiary flue gas and discharges it after treatment by the desulfurization emission device 50.

[0054] Understandably, the preset high temperature threshold and the preset low temperature threshold are set according to the actual situation. By setting the preset high temperature threshold, the air box on / off control valve located downstream of the initial sintering trolley is pre-opened during the start-up process of the sintering system. By setting the preset low temperature threshold, the air box on / off control valve located upstream of the end sintering trolley is closed after the end sintering trolley leaves the position of the previous exhaust air box during the shutdown process of the sintering system.

[0055] Furthermore, during the continuous operation of the sintering system, the head bellows mechanism is in the open state, and all bellows on / off control valves 142 are in the open state. The flue gas pretreatment device 20 receives the initial flue gas discharged from the main flue duct 12, filters the large particulate dust in the initial flue gas, and then discharges the secondary flue gas to the flue gas treatment heat recovery and utilization device 30. The flue gas treatment heat recovery and utilization device 30 receives the secondary flue gas and burns it to raise its temperature. After mixing and denitrification treatment, it outputs tertiary flue gas. The bag filter dust collector 40 further filters the tertiary flue gas and discharges it after treatment by the desulfurization emission device 50.

[0056] When the sintering system is under maintenance, the head bellows mechanism is closed, and all bellows on / off control valves are shut off. The combustion mechanism receives blast furnace gas and burns it to produce effective flue gas. This effective flue gas enters the bag filter and is then discharged through the chimney to prevent low-temperature condensation corrosion of the bag filter. Understandably, maintenance typically lasts one day, and the biggest concern is the risk of corrosion after the bag filter cools down. During maintenance, the sintering machine is stopped, so there is no flue gas. With all bellows on / off control valves closed, no flue gas is discharged from the main flue. At this time, high-temperature flue gas (effective flue gas) is generated by burning blast furnace gas in the combustion chamber. This high-temperature flue gas enters the bag filter to prevent low-temperature condensation corrosion of the bag filter.

[0057] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for baghouse dust collection of flue gas at the sintering machine head, used in a baghouse dust collection system for flue gas at the sintering machine head, characterized in that, Includes the following steps: The sintering machine head flue gas bag filter system includes a sintering device and a flue gas pretreatment device, a flue gas heat recovery and utilization device, a bag filter mechanism, and a desulfurization emission device arranged sequentially along the airflow direction. The sintering device includes a sintering machine, a main flue, a head bellows mechanism arranged near the head of the sintering machine, and a middle and tail bellows mechanism located downstream of the head bellows mechanism. The middle and tail bellows mechanism includes multiple exhaust units arranged sequentially and bellows on / off control valves arranged one-to-one with the exhaust units. The exhaust units are used to connect the sintering machine and the main flue. The flue gas pretreatment device, the flue gas heat recovery and utilization device, the bag filter mechanism, and the desulfurization emission device are sequentially located downstream of the main flue. During the start-up of the sintering system, the head bellows mechanism is pre-activated to provide reaction conditions for ignition. As the initial sintering trolley moves from its initial loading and ignition stage to the end bellows, the current position of the leading initial sintering trolley is acquired. Before the initial sintering trolley reaches the next exhaust unit, the bellows on / off control valve downstream of the initial sintering trolley is pre-activated. The flue gas pretreatment device receives the initial flue gas discharged from the main flue and filters out large dust particles before discharging secondary flue gas into the flue gas treatment heat recovery and utilization device. The flue gas treatment heat recovery and utilization device receives the secondary flue gas and combusts it to raise its temperature. After mixing and denitrification, it outputs tertiary flue gas. The bag filter further filters the tertiary flue gas and treats it through a desulfurization emission device before discharging it externally. During the shutdown process of the sintering system, when the end sintering trolley loading and ignition moves to above the middle and tail bellows mechanism, the head bellows mechanism is shut down. During the process of moving to the end air box after the end sintering trolley is loaded and ignited, the current position information of the end sintering trolley at the end is obtained. After the end sintering trolley leaves the position of the previous exhaust unit, the air box on / off control valve upstream of the end sintering trolley is closed. The flue gas pretreatment unit receives the initial flue gas discharged from the main flue and filters and initially extinguishes sparks from the large particulate dust in the initial flue gas. Then, it discharges the secondary flue gas into the flue gas treatment heat recovery and utilization unit. The flue gas treatment heat recovery and utilization unit receives the secondary flue gas and further extinguishes sparks by combustion. After mixing and denitrification, it outputs tertiary flue gas. The bag filter further filters the tertiary flue gas and treats it through the desulfurization emission device before discharging it.

2. The baghouse dust collection method for sintering machine head flue gas according to claim 1, characterized in that, The flue gas pretreatment device includes an inlet pipe, an exhaust pipe, a rotating cone, a dust collection trough, and a dust collector cylinder with a hollow cavity. The inlet pipe and the exhaust pipe are both located on the dust collector cylinder and are respectively connected to the hollow cavity. The exhaust pipe is positioned above the inlet pipe, and the dust collector cylinder covers the rotating cone. The rotating cone is rotatably arranged around the central axis of the dust collector cylinder. The rotating cone is vertically arranged with its large-diameter end close to the rotation drive mechanism. A spiral guide groove is recessed on the outer circumferential wall of the rotating cone. The air outlet of the air inlet pipe is connected to the air outlet of the main flue.

3. The method for baghouse dust collection of sintering machine head flue gas according to claim 2, characterized in that, Fire extinguishing protrusions are provided on the outer circumferential wall of the rotating cone, and the fire extinguishing protrusions are staggered with the spiral guide groove.

4. The sintering machine head flue gas bag filter method according to any one of claims 1 to 3, characterized in that, The sintering machine head flue gas bag filter system also includes a PLC controller. The mid-tail air box mechanism also includes position sensors that are arranged one-to-one with the exhaust unit. The position sensors, the air box on / off control valve, and the PLC controller are electrically connected.

5. The method for baghouse dust collection of sintering machine head flue gas according to any one of claims 2 or 3, characterized in that, The flue gas treatment heat recovery and utilization device includes a combustion mechanism and a mixing and denitrification reaction mechanism arranged sequentially along the airflow direction. The combustion mechanism includes a combustion reaction chamber, a burner nozzle, and a gas pipe. The burner nozzle is disposed within the combustion reaction chamber, and the gas pipe is disposed on the combustion reaction chamber. The mixing and denitrification reaction mechanism includes a mixing chamber and an SCR denitrification reaction chamber arranged in sequence. The mixing chamber is equipped with an ammonia inlet pipe. The first end of the mixing chamber is connected to the outlet of the combustion reaction chamber. The second end of the mixing chamber is connected to the inlet of the SCR denitrification reaction chamber. The inlet of the combustion reaction chamber is connected to the exhaust pipe.

6. The baghouse dust collection method for sintering machine head flue gas according to claim 5, characterized in that, A waste heat boiler is also provided between the SCR denitrification reaction chamber and the bag filter dust removal mechanism.

7. The method for baghouse dust collection of sintering machine head flue gas according to claim 1, characterized in that, The desulfurization emission device includes a desulfurization chamber, an exhaust fan, and a chimney arranged sequentially along the airflow direction.

8. The method for baghouse dust collection of flue gas at the sintering machine head according to claim 1, characterized in that, During the continuous operation of the sintering system, the head bellows mechanism is in the open state, all bellows on / off control valves are in the open state, the flue gas pretreatment device receives the initial flue gas discharged from the main flue, and after filtering the large particulate dust in the initial flue gas, it discharges the secondary flue gas to the flue gas treatment heat recovery and utilization device. The flue gas treatment heat recovery and utilization device receives secondary flue gas and burns it to raise its temperature. After mixing and denitrification, it outputs tertiary flue gas. The bag filter further filters the tertiary flue gas and treats it through the desulfurization emission device before discharging it to the outside. When the sintering system is under maintenance, the head bellows mechanism is closed, all bellows on / off control valves are closed, the combustion mechanism receives blast furnace gas and burns it to produce effective flue gas, which is then discharged through the chimney after entering the bag filter to prevent low-temperature condensation and corrosion of the bag filter.

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