Zero-energy-consumption white smoke removal method and device for primary flue gas diffusion chimney of converter

Abstract

The invention discloses a zero-energy-consumption white smoke removal method and device for a primary flue gas diffusion chimney of a converter. The white smoke removal device comprises a converter primary flue gas diffusion chimney, a flue gas inlet pipeline, a water baffle, a segmented drainage system, a folded plate demister, a throat spiral fin cooler, a swirler, a water collector, an upper spiral fin cooler, an ignition device and a chimney sealing plate. Flue gas is sequentially subjected to pre-dehydration, primary white smoke removal, intensified cooling, sufficient cooling and secondary white smoke removal and then is discharged into the atmosphere, water vapor in the flue gas is sufficiently condensed and removed in a segmented mode, white smoke plume and various pollutants at an outlet of a diffusion chimney can be effectively reduced, meanwhile, consumption of external energy is not increased in the whole process, and the device is low in initial investment and low in cost. The method has good economical efficiency and is widely suitable for newly-built and reformed projects.

Description

Technical Field

[0001] This invention relates to the field of dry purification and recovery technology of primary flue gas from steelmaking converters in iron and steel enterprises, specifically to a zero-energy whitening method and apparatus for the primary flue gas venting chimney of a converter. Background Technology

[0002] To ensure that the primary flue gas emissions from converters meet ultra-low emission requirements, a pre-cooling scheme using dry dust removal technology is currently commonly employed. After purification by an electrostatic precipitator, the primary flue gas from the converter is further reduced in dust concentration by water spraying in the gas cooler. Subsequently, under the control of a cup-valve switching station, the flue gas that cannot be recovered enters the venting chimney and is then discharged into the atmosphere. However, because the flue gas carries a large number of liquid droplets into the venting chimney after passing through the gas cooler, and these droplets condense upon encountering atmospheric condensation during venting, a large amount of "white plume" forms around the chimney, not only affecting the surrounding environment but also wasting water resources. Therefore, dewhitening treatment of the venting flue gas is necessary to reduce the white plume at the chimney outlet.

[0003] Currently, various industries commonly use the following three methods to treat flue gas for whitening:

[0004] (1) Flue gas condensation and whitening;

[0005] (2) Flue gas reheating and whitening;

[0006] (3) Flue gas charging and whitening.

[0007] These methods all reduce the white plume at the outlet, but methods (2) and (3) consume thermal and electrical energy respectively, while method (1) commonly uses cold water as the heat exchange medium, which also requires energy. Furthermore, the chimney height for converter primary flue gas is typically over 60m, leading to high energy consumption and cost when these methods are applied to the converter primary flue gas venting chimney. Methods and devices for dewhitening converter primary flue gas with low energy consumption and low cost still need to be explored. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a zero-energy white plume removal method and apparatus for converter primary flue gas venting chimneys. This method effectively reduces the moisture content of the flue gas without consuming additional energy, while ensuring ultra-low emissions from the converter primary flue gas, thereby reducing the white plume at the venting chimney outlet.

[0009] This invention is achieved through the following technical solution:

[0010] This invention provides a zero-energy whitening device for a converter primary flue gas venting chimney, comprising a converter primary flue gas venting chimney, a flue gas inlet pipe, a baffle plate, a segmented drainage system, a baffle plate demister, a throat spiral finned cooler, a cyclone separator, a water collector, an upper spiral finned cooler, an ignition device, and a chimney sealing plate.

[0011] The converter primary flue gas venting chimney consists of a lower straight pipe section, a narrowing section, a throat, a diffuser section, and an upper straight pipe section connected sequentially from bottom to top;

[0012] A baffle plate is installed on the inner wall of the flue gas inlet pipe;

[0013] The baffle plate demister is installed in the lower straight pipe section of the chimney and is higher than the flue gas inlet pipe;

[0014] The chimney sealing plate is installed at an angle inside the lower end of the chimney, with its lowest point lower than the flue gas inlet pipe, which is connected to the lower part of the chimney.

[0015] The cyclone separator includes a fixed plate and cyclone blades mounted on the fixed plate. The diameter of the fixed plate is smaller than the diameter of the chimney at its location. One end of the cyclone blades is connected to the fixed plate, and the other end of the cyclone blades is connected to the inner wall of the chimney. The cyclone separator is arranged at the beginning of the upper straight pipe section of the chimney, and the flue gas rises from bottom to top through the gaps between the cyclone blades to generate swirl.

[0016] The ignition device is installed in the upper straight pipe section of the chimney and located above the hydrocyclone. The water collector is arranged between the hydrocyclone and the ignition device. The water collector includes a porous annular wall and an annular sealing plate connected to the bottom edge of the porous annular wall. The porous annular wall is uniformly provided with holes. The central hole of the annular sealing plate communicates with the central hole of the porous annular wall. The annular sealing plate is connected to the inner wall of the chimney to seal the gap between the bottom edge of the porous annular wall and the inner wall of the chimney.

[0017] The segmented drainage system includes a first drain outlet, a second drain outlet, a third drain outlet, several drain pipes, and a gas drainer. The first drain outlet is located at the bottom of the flue gas inlet pipe, the second drain outlet is located on the chimney at the lowest point corresponding to the bottom of the chimney sealing plate, and the third drain outlet is located on the chimney at the lowest point corresponding to the bottom of the annular sealing plate of the water collector. The first drain outlet, the second drain outlet, and the third drain outlet are all connected to the gas drainer through drain pipes.

[0018] Preferably, there are two baffles, which are semi-circular rings. The two baffles are staggered and arranged on the inner wall of the flue gas inlet pipe. One baffle is welded to the lower part of the inner wall of the flue gas inlet pipe, and the other baffle is welded to the upper part of the inner wall of the flue gas inlet pipe.

[0019] Preferably, the folding plate demister includes two sets of support beams arranged in parallel at the top and bottom, and multiple folding plates installed between the two sets of support beams, with both ends of the support beams connected to the inner wall of the chimney.

[0020] Preferably, the upper spiral finned cooler includes fins spirally wrapped around the outer wall of the upper cylindrical body of the chimney; the throat spiral finned cooler includes fins spirally wrapped around the outer wall of the throat of the chimney.

[0021] This invention also provides a whitening method based on a zero-energy whitening device for a converter primary flue gas venting chimney, comprising the following steps:

[0022] (1) Pre-dehydration: After the flue gas enters the converter primary flue gas venting chimney zero-energy whitening device, it first passes through the flue gas inlet pipe. The droplets on the wall of the flue gas inlet pipe and some droplets in the flue gas are intercepted by the baffle plate and finally collect at the bottom of the flue gas inlet pipe. Then it is discharged through the first drain outlet at the bottom of the flue gas inlet pipe to achieve pre-dehydration and reduce the droplets in the flue gas.

[0023] (2) Primary whitening: After the flue gas enters the chimney through the flue gas inlet pipe, it enters the baffle plate demister. When the flue gas with droplets passes through the baffle plate demister, the flue gas flow line is deflected, causing the droplets to be intercepted by the baffle plate. Larger droplets can be effectively separated from the flue gas. The intercepted droplets flow down along the baffle plate, collect at the chimney sealing plate, and are then discharged through the second drain outlet, thus achieving primary whitening.

[0024] (3) Enhanced cooling: After passing through the baffle demister, the flue gas enters the throat of the chimney after passing through the narrow section of the chimney. The spiral fins of the throat spiral fin cooler surrounding the outer wall of the throat can enhance the heat exchange between the flue gas and the outside, which helps to reduce the temperature of the flue gas and accelerate the condensation of water vapor in the flue gas.

[0025] (4) Sufficient cooling: After being cooled by the spiral finned cooler at the throat, the flue gas passes through the diffuser section of the chimney and then enters the cyclone separator. The flue gas generates a swirling flow and then passes through the upper spiral finned cooler. The swirling flow makes the airflow more turbulent and allows it to fully contact the chimney wall, which can effectively enhance the heat exchange between the flue gas and the chimney wall. The spiral fins of the upper spiral finned cooler surrounding the outer wall of the chimney can effectively enhance the heat exchange between the chimney wall and the outside. Under the enhanced heat exchange effect of swirling flow-finned coupling, the flue gas is fully cooled, allowing the water vapor in the flue gas to fully condense.

[0026] (5) Secondary de-whitening: After the flue gas is fully cooled by the upper spiral finned cooler, the water vapor in the flue gas is fully condensed and released. The water mist enters the water collector under the action of swirling flow and separates from the flue gas. The water vapor attached to the porous cylindrical wall or the inner wall of the chimney is finally collected at the annular sealing plate of the water collector and then discharged through the third drain outlet to achieve secondary de-whitening.

[0027] The converter primary flue gas venting chimney zero-energy whitening device provided by the present invention has the following beneficial effects:

[0028] 1) Through pre-dehydration by baffle plate, primary de-whitening by baffle plate demister, enhanced cooling by throat spiral fin cooler, full cooling by cyclone separator and upper spiral fin cooler, and secondary de-whitening by water collector, water vapor in flue gas is fully condensed and removed, effectively reducing the moisture content of flue gas and efficiently reducing the white plume at the chimney outlet, resulting in good social benefits.

[0029] 2) Cooling is achieved through natural heat dissipation, utilizing the kinetic energy of the flue gas itself for dewhitening. The entire process does not increase the consumption of external energy, which meets the requirements of energy conservation and emission reduction.

[0030] 3) A segmented drainage system is adopted, where condensate is collected from each drain outlet through drain pipes and then discharged through a gas drainer. This shortens the path of condensate as it flows downwards along the wall and reduces the risk of condensate being carried away by airflow. After collection, the condensate can be discharged in a timely, smooth, and safe manner, ensuring the whitening effect. In addition, the condensate can be recycled and reused, avoiding waste of water resources.

[0031] 4) By adopting a thorough condensation and dehydration method, not only can the water content in the flue gas be reduced, but also particulate matter and gaseous pollutants in the flue gas can be removed, further reducing the emission concentration of particulate matter and gaseous pollutants in the flue gas, which helps to achieve ultra-low emissions.

[0032] 5) This device requires low initial investment, is highly economical, and is easy to install with a short construction period. It can directly modify existing converter primary flue gas venting chimneys and is widely applicable to new construction and renovation projects. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the zero-energy whitening device for the converter primary flue gas venting chimney according to an embodiment of the present invention;

[0034] Figure 2 This is a side view of the water collector according to an embodiment of the present invention;

[0035] Figure 3 This is a top view of the hydrocyclone according to an embodiment of the present invention;

[0036] Figure 4 This is a side view of the folding plate demister according to an embodiment of the present invention;

[0037] Figure 5 This is a schematic diagram of the water baffle plate according to an embodiment of the present invention. Detailed Implementation

[0038] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0039] like Figures 1 to 5 As shown in the figure, this embodiment discloses a zero-energy whitening device for the primary flue gas venting chimney of a converter, which is connected to the outlet pipe of the cup valve switching station in the dry dust removal system of the converter. Flue gas that cannot be recovered is discharged into the atmosphere through this device.

[0040] Specifically, the converter primary flue gas venting chimney zero-energy whitening device includes a converter primary flue gas venting chimney 1, flue gas inlet pipe 2, baffle plate 3, segmented drainage system 4 (referred to as drainage system), baffle plate demister 5, throat spiral fin cooler 6, cyclone separator 7, water collector 8, upper spiral fin cooler 9, ignition device 10, and chimney sealing plate 11.

[0041] The converter's primary flue gas venting chimney 1, ignition device 10, and flue gas inlet pipe 2 are all conventional designs. For example... Figure 1 The converter primary flue gas venting chimney has a throat 101, a diffuser section 102, a narrowing section 103, a lower straight pipe section 104, and an upper straight pipe section 105, which are connected sequentially from bottom to top.

[0042] Two baffle plates 3 are provided. The baffle plates 3 are made of angle steel or flat steel and are semi-circular rings. The two baffle plates 3 are welded to the inner wall of the flue gas inlet pipe 2 at a 180° angle. The two baffle plates 3 are staggered and set on the inner wall of the flue gas inlet pipe 2. One baffle plate 3 is welded to the lower part of the inner wall of the flue gas inlet pipe 2 (close to the flue gas inlet) to prevent condensate in the chimney 1 from flowing back to the flue gas inlet pipe 2 along the pipe wall. The other baffle plate 3 is welded to the upper part of the inner wall of the flue gas inlet pipe 2 (arranged at the rear, closer to the chimney 1) to intercept droplets on the pipe wall and some droplets in the flue gas, preventing them from entering the venting chimney 1. The intercepted condensate is discharged through the drainage system 4.

[0043] The folding plate demister 5 includes two sets of parallel support beams 52 and a folding plate 51 installed between the two sets of support beams 52. The two ends of the support beams 52 are connected to the inner wall of the chimney 1. The folding plate demister 5 is arranged in the lower straight pipe section 104 of the chimney 1, which is higher than the flue gas inlet pipe 2. The angle, thickness, and spacing of the folding plate 51 of the folding plate demister 5 are designed according to the working conditions. Liquid droplets in the flue gas can be intercepted by the folding plate 51, and then flow down along the folding plate 51, collect at the chimney sealing plate 11, and then be discharged through the drainage system 4.

[0044] The chimney sealing plate 11 is installed at an angle inside the lower straight pipe section 104 of the chimney 1, with its lowest point lower than the flue gas inlet pipe 2, to prevent water from accumulating at the bottom of the chimney 1 and being difficult to drain. The liquid droplets in the flue gas input from the flue gas inlet pipe 2 can be intercepted by the bend plate 51, and then flow down along the bend plate 51, collecting at the chimney sealing plate 11.

[0045] The throat spiral finned cooler 6 includes fins spirally wrapped around the outer wall of the chimney throat 101; the fins of the throat spiral finned cooler 6 spirally wrapped around the outer wall of the chimney throat 101 enhance the heat exchange of flue gas in the chimney throat 101 and accelerate the condensation of water vapor in the flue gas.

[0046] The cyclone separator 7 includes a fixed plate 72 and cyclone blades 71 mounted on the fixed plate 72. The diameter of the fixed plate 72 is smaller than the diameter of the chimney 1 at its location. One end of the cyclone blades 71 is connected to the fixed plate 72, and the other end of the cyclone blades 71 is connected to the inner wall of the chimney 1. The cyclone separator 7 is arranged at the beginning of the upper straight pipe section 105 of the chimney. The flue gas rises from bottom to top through the gaps between the cyclone blades 71, generating a swirling flow. The size, number, and spatial angle of the cyclone blades 71 of the cyclone separator 7 are designed according to the working conditions. After the flue gas passes through the cyclone separator, it generates a swirling flow, thereby making full contact with the inner wall of the chimney 1 for further cooling. At the same time, the water mist in the flue gas is thrown into the water collector 8 (that is, between the porous annular wall 81 and the inner wall of the chimney 1).

[0047] The ignition device is installed in the upper straight pipe section of the chimney and located above the cyclone separator. The water collector 8 includes a porous annular wall 81 and an annular sealing plate 83 connected to the bottom edge of the porous annular wall 81. The porous annular wall 81 is evenly provided with holes 82. The central hole of the annular sealing plate 83 communicates with the central hole of the porous annular wall 81. The annular sealing plate 83 connects to the inner wall of the chimney 1 to seal the gap between the bottom of the porous annular wall 81 and the inner wall of the chimney 1. The size and spacing of the holes 82 on the porous annular wall 81 of the water collector 8 are designed according to the working conditions. The water collector 8 is arranged between the cyclone separator 7 and the ignition device 10. Water mist enters the interior of the water collector 8 through the porous annular wall 81 under the action of the cyclone, adheres to the porous annular wall 81 or the inner wall of the chimney 1, and then collects downward at the third drain outlet 43 at the bottom of the water collector 8, and is finally discharged through the drainage system 4.

[0048] The upper spiral finned cooler 9 includes fins spirally wrapped around the outer wall of the upper straight pipe section 105 of the chimney. The fins of the upper spiral finned cooler 9 spirally wrapped around the outer wall of the upper straight pipe section 105 of the chimney 1 enhance the heat exchange of flue gas in the swirl section and accelerate the condensation of water vapor in the flue gas.

[0049] The segmented drainage system 4 includes a first drain outlet 41, a second drain outlet 42, a third drain outlet 43, several drain pipes 44, and a gas drainer 45. The first drain outlet 41 is located at the bottom of the flue gas inlet pipe 2 (between the two baffles 3). The second drain outlet 42 is located on the chimney 1 at the lowest point corresponding to the chimney sealing plate 11. The third drain outlet 43 is located on the chimney 1 at the lowest point corresponding to the annular sealing plate 83 of the water collector 8. The first drain outlet 41, the second drain outlet 42, and the third drain outlet 43 are all connected to the gas drainer 45 through the drain pipes 44, and the condensate separated from the flue gas is discharged in segments. The condensate is collected through the drain pipes 44 and then discharged into the gas drainer 45.

[0050] This embodiment also provides a whitening method based on the above-mentioned zero-energy whitening device for the converter primary flue gas venting chimney. When the converter primary flue gas needs to be vented, it enters the zero-energy whitening device for the converter primary flue gas venting chimney after passing through the cup valve switching station. After pre-dehydration, primary whitening, enhanced cooling, sufficient cooling, and secondary whitening, it is discharged into the atmosphere. The method specifically includes the following steps:

[0051] 1) Pre-dehydration: After the flue gas enters the primary flue gas venting chimney device of the zero-energy whitening converter, it first passes through the flue gas inlet pipe 2. The droplets on the wall of the flue gas inlet pipe 2 and some droplets in the flue gas are intercepted by the baffle plate 3 and finally collect at the bottom of the flue gas inlet pipe 2. Then it is discharged through the first drain outlet 41 at the bottom of the flue gas inlet pipe 2, thus achieving pre-dehydration and reducing the droplets in the flue gas.

[0052] 2) Primary dehydration: After pre-dehydration, the flue gas enters the chimney through the flue gas inlet pipe 2 and then enters the baffle plate demister 5. When the flue gas with droplets passes through the baffle plate demister 5, the flue gas flow line is deflected, causing the droplets to be intercepted by the baffle plate. Larger droplets can be effectively separated from the flue gas. The intercepted droplets flow down along the baffle plate 51, collect at the chimney sealing plate 11, and are then discharged through the second drain outlet 42, achieving primary dehydration and significantly reducing the number of droplets in the flue gas.

[0053] 3) Enhanced cooling: After passing through the baffle demister 5, the flue gas enters the throat 101 of the chimney after passing through the narrow section 103 of the chimney. The spiral fins (throat spiral fin cooler 6) surrounding the outer wall of the throat can effectively enhance the heat exchange between the flue gas and the outside world in the throat 101, which helps to reduce the flue gas temperature and accelerate the condensation of water vapor in the flue gas.

[0054] 4) Sufficient cooling: After being cooled by the spiral finned cooler 6 at the throat, the flue gas passes through the diffuser section 102 of the chimney and then enters the cyclone separator 7. The flue gas generates a swirling flow and then passes through the upper spiral finned cooler 9. The swirling flow makes the airflow more turbulent and allows it to fully contact the wall of the chimney 1, which can effectively enhance the heat exchange between the flue gas and the wall of the chimney 1. The spiral fins surrounding the outer wall of the chimney 1 (upper spiral finned cooler 9) can effectively enhance the heat exchange between the wall of the chimney 1 and the outside. Under the enhanced heat exchange effect of swirling flow-finned coupling, the flue gas is fully cooled, allowing the water vapor in the flue gas to fully condense.

[0055] 5) Secondary de-whitening: After the flue gas is fully cooled by the upper spiral finned cooler 9, the water vapor in the flue gas is fully condensed and released. The water mist in the central hole of the porous annular wall 81 passes through the porous annular wall 81 under the action of swirling flow and enters the water collector 8. In the water collector 8, the flue gas and condensate are efficiently separated. Due to the centrifugal force, the water vapor entering the water collector 8 can hardly escape from the water collector 8 through the porous annular wall 81. Finally, the water attached to the porous annular wall 81 of the water collector 8 or the inner wall of the chimney 1, together with the water condensed directly on the porous annular wall 81 or the inner wall of the chimney 1, flows down together and finally collects at the annular sealing plate 83 of the water collector 8, and is discharged through the third drain outlet 43 at the lower position, realizing secondary de-whitening and effectively reducing the moisture content of the flue gas again.

[0056] By employing the above-mentioned device and method, zero-energy, low-cost, and highly efficient dewhitening treatment of converter primary flue gas is achieved, solving the problem of a large amount of "white fog" forming around the converter primary flue gas venting chimney. This method offers the following advantages and beneficial effects:

[0057] 1) By pre-dehydration, primary de-whitening, enhanced cooling, full cooling and secondary de-whitening, water vapor in the flue gas is fully condensed and removed, the moisture content of the flue gas is effectively reduced, and the white plume at the outlet of chimney 1 is efficiently reduced, which has good social benefits.

[0058] 2) Cooling is achieved through natural heat dissipation, utilizing the kinetic energy of the flue gas itself for dewhitening. The entire process does not increase the consumption of external energy, which meets the requirements of energy conservation and emission reduction.

[0059] 3) A segmented drainage method is adopted. A first drain outlet 41 is installed at the pre-dehydration stage; a chimney sealing plate 11 and a second drain outlet 42 are installed at the primary bleaching stage; and a water collector 8 and a third drain outlet 43 are installed at the secondary bleaching stage. Condensate is collected from each drain outlet via drain pipe 44 and then discharged through a gas drainer 45. This shortens the path of condensate flowing downwards along the wall and reduces the risk of condensate being re-entrained by airflow. After collection, the condensate can be discharged promptly, smoothly, and safely, ensuring the bleaching effect. Furthermore, the condensate can be recycled and reused, avoiding water waste.

[0060] 4) By adopting a thorough condensation and dehydration method, not only can the water content in the flue gas be reduced, but also particulate matter and gaseous pollutants in the flue gas can be removed, further reducing the emission concentration of particulate matter and gaseous pollutants in the flue gas, which helps to achieve ultra-low emissions.

[0061] 5) The spiral fins surrounding the outer wall of the chimney 1 used in the throat spiral fin cooler 6 and the upper spiral fin cooler 9 also have the function of reinforcing the chimney 1, which helps to enhance the strength of the chimney 1.

[0062] 6) Two baffles 3 are used to achieve a two-way water blocking effect. They not only intercept the droplets on the flue gas duct wall and some droplets in the flue gas to prevent them from entering the chimney 1, but also intercept the condensate formed in the chimney 1 to prevent it from flowing back to the flue gas duct along the pipe wall.

[0063] 7) The initial investment of the equipment is low, which makes it highly economical. It is also simple to install and has a short construction period. It can directly modify the existing converter primary flue gas venting chimney and is widely applicable to new construction and renovation projects.

[0064] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features therein. These modifications or substitutions do not cause the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention. Therefore, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

Claims

1. A zero-energy-consumption desulfurization device for primary flue gas venting chimney of a converter, characterized in that, It includes a converter primary flue gas venting chimney, flue gas inlet pipe, baffle plate, segmented drainage system, baffle plate demister, throat spiral finned cooler, cyclone separator, water collector, upper spiral finned cooler, ignition device and chimney sealing plate; The converter primary flue gas venting chimney consists of a lower straight pipe section, a narrowing section, a throat, a diffuser section, and an upper straight pipe section connected sequentially from bottom to top; A baffle plate is installed on the inner wall of the flue gas inlet pipe; The baffle plate demister is installed in the lower straight pipe section of the chimney and is higher than the flue gas inlet pipe; The chimney sealing plate is installed at an angle inside the lower end of the chimney, with its lowest point lower than the flue gas inlet pipe, which is connected to the lower part of the chimney. The cyclone separator includes a fixed plate and cyclone blades mounted on the fixed plate. The diameter of the fixed plate is smaller than the diameter of the chimney at its location. One end of the cyclone blades is connected to the fixed plate, and the other end of the cyclone blades is connected to the inner wall of the chimney. The cyclone separator is arranged at the beginning of the upper straight pipe section of the chimney, and the flue gas rises from bottom to top through the gaps between the cyclone blades to generate swirl. The ignition device is installed in the upper straight pipe section of the chimney and located above the hydrocyclone. The water collector is arranged between the hydrocyclone and the ignition device. The water collector includes a porous annular wall and an annular sealing plate connected to the bottom edge of the porous annular wall. The porous annular wall is uniformly provided with holes. The central hole of the annular sealing plate communicates with the central hole of the porous annular wall. The annular sealing plate is connected to the inner wall of the chimney to seal the gap between the bottom edge of the porous annular wall and the inner wall of the chimney. The segmented drainage system includes a first drain outlet, a second drain outlet, a third drain outlet, several drain pipes, and a gas drainer. The first drain outlet is located at the bottom of the flue gas inlet pipe, the second drain outlet is located on the chimney at the lowest point corresponding to the bottom of the chimney sealing plate, and the third drain outlet is located on the chimney at the lowest point corresponding to the bottom of the annular sealing plate of the water collector. The first drain outlet, the second drain outlet, and the third drain outlet are all connected to the gas drainer through drain pipes.

2. The zero-energy whitening device for converter primary flue gas venting chimney as described in claim 1, characterized in that: The water baffle has two sections, which are semi-circular in shape. The two water baffles are staggered and installed on the inner wall of the flue gas inlet pipe. One water baffle is welded to the lower part of the inner wall of the flue gas inlet pipe, and the other water baffle is welded to the upper part of the inner wall of the flue gas inlet pipe.

3. The zero-energy whitening device for converter primary flue gas venting chimney as described in claim 1, characterized in that: The folding plate demister includes two sets of support beams arranged in parallel at the top and bottom, and multiple folding plates installed between the two sets of support beams. The two ends of the support beams are connected to the inner wall of the chimney.

4. The zero-energy whitening device for converter primary flue gas venting chimney as described in claim 1, characterized in that: The upper spiral finned cooler includes fins spirally wrapped around the outer wall of the upper straight cylindrical body of the chimney; the throat spiral finned cooler includes fins spirally wrapped around the outer wall of the throat of the chimney.

5. A whitening method based on the zero-energy whitening device for converter primary flue gas venting chimney as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Pre-dehydration: After the flue gas enters the converter primary flue gas venting chimney zero-energy whitening device, it first passes through the flue gas inlet pipe. The droplets on the wall of the flue gas inlet pipe and some droplets in the flue gas are intercepted by the baffle plate and finally collect at the bottom of the flue gas inlet pipe. Then it is discharged through the first drain outlet at the bottom of the flue gas inlet pipe to achieve pre-dehydration and reduce the droplets in the flue gas. (2) Primary whitening: After the flue gas enters the chimney through the flue gas inlet pipe, it enters the baffle plate demister. When the flue gas with droplets passes through the baffle plate demister, the flue gas flow line is deflected, causing the droplets to be intercepted by the baffle plate. Larger droplets can be effectively separated from the flue gas. The intercepted droplets flow down along the baffle plate, collect at the chimney sealing plate, and are then discharged through the second drain outlet, thus achieving primary whitening. (3) Enhanced cooling: After passing through the baffle demister, the flue gas enters the throat of the chimney after passing through the narrow section of the chimney. The spiral fins of the throat spiral fin cooler surrounding the outer wall of the throat can enhance the heat exchange between the flue gas and the outside, which helps to reduce the temperature of the flue gas and accelerate the condensation of water vapor in the flue gas. (4) Sufficient cooling: After being cooled by the spiral finned cooler at the throat, the flue gas passes through the diffuser section of the chimney and then enters the cyclone separator. The flue gas generates a swirling flow and then passes through the upper spiral finned cooler. The swirling flow makes the airflow more turbulent and allows it to fully contact the chimney wall, which can effectively enhance the heat exchange between the flue gas and the chimney wall. The spiral fins of the upper spiral finned cooler surrounding the outer wall of the chimney can effectively enhance the heat exchange between the chimney wall and the outside. Under the enhanced heat exchange effect of swirling flow-finned coupling, the flue gas is fully cooled, allowing the water vapor in the flue gas to fully condense. (5) Secondary de-whitening: After the flue gas is fully cooled by the upper spiral finned cooler, the water vapor in the flue gas is fully condensed and released. The water mist enters the water collector under the action of swirling flow and separates from the flue gas. The water vapor attached to the porous cylindrical wall or the inner wall of the chimney is finally collected at the annular sealing plate of the water collector and then discharged through the third drain outlet to achieve secondary de-whitening.

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