A steel smelting waste heat recovery device and method

Abstract

The application discloses a steel smelting waste heat recovery device and method, and particularly relates to the technical field of steel smelting waste heat recovery, which comprises a main treatment box, a gas outlet pipe arranged at the top end of the main treatment box, a gas collection cover arranged at the bottom end of the main treatment box, a gas inlet pipe arranged at the bottom end of the gas collection cover, a first heat exchange unit arranged on the main treatment box and used for heat exchange of high-temperature steel smelting flue gas entering the main treatment box, and a pretreatment cylinder. The pretreatment cylinder is arranged below the main treatment box, a rotatable filter cylinder is arranged between the main treatment box and the pretreatment cylinder, and the second heat exchange unit is arranged, so that efficient gas-solid separation can be completed before the flue gas enters the main treatment box for heat exchange, solid particles in high-temperature dust-containing flue gas are removed in advance, and particle heat is recovered separately, thereby effectively solving the problems that only flue gas heat is recovered in the traditional waste heat device, high-temperature dust particles waste heat is wasted, and dust particles are easy to wear the heat exchange tube bundle or block the dust screen surface.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology in iron and steel smelting, and in particular to a waste heat recovery device and method for iron and steel smelting. Background Technology

[0002] Iron and steel smelting is a typical high-energy-consuming and high-emission industry in the heavy industry sector. During the iron and steel smelting process, a series of processes such as high-temperature furnace combustion, ore melting, and scrap steel smelting often generate a large amount of high-temperature dust-laden flue gas. If smelting flue gas is directly emitted into the environment, it will seriously pollute the atmospheric environment. Therefore, it is necessary to purify the flue gas to avoid direct emission and damage to the ecological environment. Meanwhile, since the flue gas generated by smelting also carries extremely high temperatures and a large amount of heat energy, it contains abundant waste heat resources. If it is not effectively recovered and utilized, it will cause serious waste of energy resources and heat loss, which does not meet the production requirements of industrial energy conservation and carbon reduction. Therefore, waste heat recovery is often required before purifying the flue gas from steel smelting.

[0003] Currently, existing waste heat recovery devices in steel smelting mostly operate by arranging heat exchange tube bundles inside a container and using water as a medium to exchange heat with high-temperature flue gas, absorbing the waste heat from the flue gas. The heated water can then be used for heating in the plant, equipment heating, and raw material drying, thus achieving the recovery and utilization of waste heat from the flue gas. However, since steel smelting flue gas often contains a large amount of slag (dust particles), these particles easily adhere to and accumulate on the surface of the heat exchange tubes during the heat exchange process, forming scale and ash deposits. This significantly reduces heat exchange efficiency, and long-term accumulation can also cause blockages in the heat exchange pipelines, affecting the normal operation of the equipment. Therefore, existing equipment often uses dustproof nets to intercept dust particles in front of the heat exchange structure or sets up a descaling structure inside the heat exchange structure to regularly clean and descale the surface of the heat exchange tube bundles. For example, in patent number "CN117606256A" entitled "A High-Efficiency Waste Heat Recovery Device for Iron and Steel Smelting," a dust-blocking mesh is used to separate larger dust particles contained in the high-temperature environment, preventing large dust particles from directly contacting the heat exchange tube bundle. In patent number "CN115289875B" entitled "A High-Efficiency Waste Heat Recovery Device for Iron and Steel Smelting," a cleaning liquid is sprayed from nozzles to clean the heat exchange tubes, preventing impurities from adhering to the heat exchange tubes and their fins. However, the former's dust-blocking mesh interception method... In the continuous production process of steel smelting, dust particles accumulate in large quantities in a short period of time, causing mesh blockage and poor flue gas flow. The latter cleaning method is complex due to the large number of internal pipes, making inspection and maintenance difficult and the operating cost extremely high. More importantly, since the dust particles themselves carry a lot of waste heat, both methods will cause the heat of the high-temperature dust particles to be lost, resulting in extremely low energy utilization. At the same time, when the flue gas passes through the heat exchange tubes, the short passage and high flow rate often result in insufficient heat exchange between the flue gas and the tube bundle, resulting in a better overall waste heat recovery effect.

[0004] Therefore, how to provide a waste heat recovery device for iron and steel smelting is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a waste heat recovery device and method for iron and steel smelting.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A waste heat recovery device for iron and steel smelting, comprising: The main processing box has an exhaust pipe at its top and an exhaust hood at its bottom, with an intake pipe at the bottom of the exhaust hood. The first heat exchange unit is installed on the main processing box and is used to exchange heat with the high-temperature steel smelting flue gas introduced into the main processing box. The pretreatment cylinder is mounted below the gas collection hood via a bracket, and its side wall is provided with a smoke inlet pipe; The filter cartridge has a connecting cylinder at its top end. The connecting cylinder is movably connected to the top end of the pretreatment cartridge via a bearing. The top end of the connecting cylinder passes through the pretreatment cartridge and is rotatably connected to the bottom end of the air inlet pipe via a rotary joint. The pretreatment cartridge is equipped with a rotating mechanism for driving the connecting cylinder to rotate. A material removal mechanism is disposed inside the pretreatment cylinder and is configured to assist in separating the high-temperature slag from the outer wall of the filter cylinder when the filter cylinder rotates. The second heat exchange unit is disposed on the pretreatment cylinder and is used to exchange heat with the high-temperature slag falling into the pretreatment cylinder.

[0007] As a further aspect of the present invention, the first heat exchange unit includes: Several sets of heat exchange tubes are arranged in an array inside the main processing box; Two water storage tanks are symmetrically arranged at both ends of the main treatment tank, and the two ends of the heat exchange tube are respectively connected to the two water storage tanks; One of the water storage tanks is provided with a first water inlet pipe at one end, and the other water storage tank is provided with a first water outlet pipe at one end.

[0008] As a further aspect of the present invention, the second heat exchange unit includes: A heat exchange cylinder is located at the bottom of the pretreatment cylinder. The bottom of the pretreatment cylinder has a conical structure and is connected to a slag discharge pipe. The bottom of the slag discharge pipe extends outside the heat exchange cylinder and is equipped with a control valve. The second water inlet pipe is located above the side wall of the heat exchange cylinder and is used to introduce water into the heat exchange cylinder. The second water outlet pipe is located below the side wall of the heat exchange cylinder and is used to discharge water from the heat exchange cylinder.

[0009] As a further embodiment of the present invention, the rotating mechanism includes a drive motor, which is fixed to the side wall of the pretreatment cylinder by a bracket, and its output end is connected to a first synchronous pulley. A second synchronous pulley is provided at the top of the connecting cylinder near the top of the pretreatment cylinder, and a synchronous belt is sleeved between the second synchronous pulley and the first synchronous pulley.

[0010] As a further aspect of the present invention, the material removal mechanism includes a material removal plate and several sets of elastic telescopic members; The material removal plate is axially inclined between the inner side of the pretreatment cylinder and the outer side of the filter cylinder, and the inner inclined arc surface of the material removal plate is in contact with the outer wall of the filter cylinder. The outer side of the material removal plate is connected to the inner wall of the pretreatment cylinder through several sets of elastic expansion members, and the elastic expansion members provide radial preload, so that the inner inclined arc surface of the material removal plate is always in close contact with the outer wall of the filter cylinder when the filter cylinder rotates.

[0011] As a further embodiment of the present invention, the elastic telescopic member includes a support cylinder and a support rod that are interlocked with each other. One end of the support cylinder is fixedly connected to the pretreatment cylinder, and a spring is fixedly installed inside the support cylinder. One end of the support rod is fixedly connected to the spring, and the other end is fixedly connected to the material removal plate.

[0012] As a further aspect of the present invention, the waste heat recovery device for iron and steel smelting also includes: The partition includes several upper partitions and several lower partitions. The several upper partitions are located at the top inside the main processing box, and the several lower partitions are located at the bottom inside the main processing box. The upper partitions and lower partitions are arranged alternately. A flow guide is installed above the inner cavity of the gas collection hood, and the top branch of the flow guide is connected to the bottom of several lower partitions respectively. The upper partition, lower partition and flow guide form multiple continuous zigzag flue gas flow paths in the main processing box. The heat exchange tube is arranged longitudinally along the zigzag flue gas flow paths. Several guide vanes, each corresponding to one of the heat exchange tubes, are arranged in an alternating pattern within the loop-shaped flue gas flow path.

[0013] As a further embodiment of the present invention, the guide plate includes an inner arc segment and an outer arc segment, and the distance between the tube wall of the heat exchange tube and the inner arc segment of the guide plate gradually decreases along the flue gas forward direction.

[0014] As a further embodiment of the present invention, an exhaust fan is provided inside the air outlet pipe.

[0015] A method for recovering waste heat from an iron and steel smelting waste heat recovery device, using the aforementioned iron and steel smelting waste heat recovery device, includes the following steps: S1. High-temperature steel smelting flue gas is fed into the pretreatment cylinder through the flue pipe. S2. Flue gas is drawn into the inner cavity through the filter holes of the filter cylinder. The slag in the flue gas is trapped on the outer wall of the filter cylinder. The filter cylinder rotates around its own axis and uses centrifugal force to initially throw off the slag attached to the outer wall. At the same time, the material removal mechanism further scrapes and separates the slag on the outer wall of the filter cylinder and guides the slag downward through its oblique arc guiding action. S3. Under the action of gravity, the high-temperature slag falls into the conical bottom of the pretreatment cylinder. The heat exchange medium is introduced into the heat exchange cylinder. The accumulated high-temperature slag heats the medium in the heat exchange cylinder, realizing the recovery of the heat of the slag itself. The cooled slag can be discharged out through the open slag discharge pipe to complete the solidification process. S4. The high-temperature flue gas entering the filter cartridge is guided into the gas collection hood through the connecting tube, and then diverted into two sets of symmetrically arranged loop flue gas flow paths in the main treatment box. During the back-and-forth flow of the high-temperature flue gas, it flows through the heat exchange tubes arranged longitudinally on the path in sequence. With the convergence and guidance of the staggered flow guide plates, the convective heat exchange between the high-temperature flue gas and the circulating water in the heat exchange tube is enhanced, so as to achieve efficient recovery of the high-temperature heat of the gas. S5. After heat exchange and cooling, the gas flows upward along the loop-shaped flue gas flow path and converges into the outlet pipe, and is discharged outward through the outlet pipe, thus completing the waste heat recovery operation.

[0016] The technical effects and advantages provided by the present invention in the above technical solution are as follows: This invention, by setting a pretreatment cylinder below the main treatment box and a rotatable filter cylinder between them, and in conjunction with a second heat exchange unit, can complete efficient gas-solid separation before the flue gas enters the main box for heat exchange, remove solid particles from the high-temperature dust-laden flue gas in advance and recover the heat of the particles separately. This effectively solves the problems of traditional waste heat devices that only recover the heat of the flue gas, resulting in the loss of waste heat from high-temperature dust particles, as well as the problems of dust particles easily wearing down the heat exchange tube bundle or clogging the dustproof mesh. By setting a material removal mechanism between the filter cartridge and the pretreatment cartridge, the inclined arc surface of the material removal plate on the material removal mechanism adaptively fits the outer wall of the filter cartridge. With the centrifugal rotation of the filter cartridge, the filter cartridge can be self-cleaned and the high-temperature slag can be concentrated and guided downward. The heat exchange tube at the bottom of the pretreatment cartridge stores and exchanges heat on the high-temperature slag, realizing the recovery of the heat of the slag itself and completing the solid material treatment. This invention forms multiple continuous, zigzag flue gas flow paths by setting up partitions and guide frames. High-temperature flue gas can flow along the zigzag flue gas flow paths and pass through the heat exchange tubes arranged longitudinally along the paths in sequence. This can greatly extend the effective heat exchange path of the high-temperature flue gas, allowing it to act evenly with each heat exchange tube and fully release the waste heat carried by the flue gas. This effectively avoids insufficient heat exchange due to short flue gas flow paths, excessive flow velocity, and heat exchange tubes, and greatly improves the waste heat recovery efficiency. By staggering the flow path of the flue gas with guide plates corresponding to the heat exchangers, and by gradually narrowing the flow gap between the inner arc section of the guide plates and the heat exchange tubes along the flue gas flow direction, a converging effect is formed on the high-temperature flue gas. This forces the flue gas to adhere tightly to the outer wall of the heat exchange tubes and continuously scour the back of the flow path. The outer arc section can smoothly guide the flue gas and regulate its flow direction, thereby greatly enhancing the heat exchange effect between the high-temperature flue gas and the medium inside the heat exchange tubes. This effectively avoids the problems of uneven and insufficient local heat exchange, and achieves efficient recovery of waste heat from high-temperature steel smelting flue gas. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is one of the overall structural schematic diagrams of the present invention; Figure 2 This is the second schematic diagram of the overall structure of the present invention; Figure 3 This is a longitudinal sectional view of the main processing box of the present invention; Figure 4 This is a schematic diagram of the internal structure of the main processing box of the present invention; Figure 5 This is a schematic diagram of the structure of the guide plate of the present invention; Figure 6 This is a schematic diagram of the connection structure between the gas collection hood, the pretreatment cylinder, and the heat exchange cylinder of the present invention; Figure 7 This is one of the schematic diagrams of the internal structure of the pretreatment cylinder of the present invention; Figure 8 This is the second schematic diagram of the internal structure of the pretreatment cylinder of the present invention; Figure 9 This is a schematic diagram of the connection structure between the filter cartridge and the material removal plate of the present invention; Figure 10 This is a schematic diagram of the connection structure between the material removal plate and the support cylinder of the present invention.

[0018] In the diagram: 100, Main treatment box; 101, Gas collection hood; 102, Flow guide frame; 103, Gas outlet pipe; 104, Exhaust fan; 105, Gas inlet pipe; 200, Heat exchanger tube; 201, Water storage tank; 202, First water inlet pipe; 203, First water outlet pipe; 300, Pretreatment cylinder; 301, Flue gas inlet pipe; 302, Slag discharge pipe; 303, Control valve; 400, Filter cartridge; 401, Connecting cylinder; 50 0. Drive motor; 501. First synchronous pulley; 502. Second synchronous pulley; 503. Synchronous belt; 600. Heat exchange cylinder; 601. Second water inlet pipe; 602. Second water outlet pipe; 700. Material removal plate; 701. Elastic telescopic component; 7001. Support cylinder; 7002. Support rod; 7003. Spring; 800. Spacer; 801. Upper partition plate; 802. Lower partition plate; 900. Guide plate. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions of the present invention, 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 embodiments of the present invention, and not all embodiments. 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] like Figures 1-4 As shown, the present invention provides a waste heat recovery device for iron and steel smelting, including a main processing box 100, a first heat exchange unit, a pretreatment cylinder 300, a filter cylinder 400, a material removal mechanism, and a second heat exchange unit; The main processing box 100 is equipped with an exhaust pipe 103 at its top and a gas collection hood 101 at its bottom. The gas collection hood 101 is equipped with an inlet pipe 105 at its bottom. An exhaust fan 104 is installed inside the exhaust pipe 103. The exhaust fan 104 provides negative pressure to make the flue gas circulate back and forth along a preset loop path, ensuring sufficient heat exchange path and uniform flow rate of the flue gas, and avoiding insufficient heat exchange caused by local flue gas stagnation. The first heat exchange unit is installed on the main processing box 100 and is used to exchange heat with the high-temperature steel smelting flue gas that enters the main processing box 100. The first heat exchange unit includes: Several sets of heat exchange tubes 200 are arranged in an array inside the main processing box 100; Two water storage tanks 201 are symmetrically arranged at both ends of the main treatment tank 100, and the two ends of the heat exchange tube 200 are respectively connected to the two water storage tanks 201. One of the water storage tanks 201 is equipped with a first inlet pipe 202 at one end, and the other water storage tank 201 is equipped with a first outlet pipe 203 at one end. Low-temperature circulating water is continuously introduced into one water storage tank 201 through the first inlet pipe 202. The low-temperature circulating water fills the interior of each set of heat exchange tubes 200 and flows along the heat exchange tubes 200 under water pressure. Finally, it flows into the other water storage tank 201 and is discharged outward through the first outlet pipe 203, realizing the continuous flow of the water medium.

[0021] The pretreatment cylinder 300 is mounted below the gas collection hood 101 via a bracket, and its side wall is provided with a smoke inlet pipe 301; the top of the filter cylinder 400 is provided with a connecting cylinder 401, which is movably connected to the top of the pretreatment cylinder 300 via a bearing, and the top of the connecting cylinder 401 passes through the pretreatment cylinder 300 and is rotatably connected to the bottom of the air inlet pipe 105 via a rotary joint; the pretreatment cylinder 300 is provided with a rotating mechanism for driving the connecting cylinder 401 to rotate. High-temperature steel smelting flue gas is fed into the pretreatment cylinder 300 through the flue gas inlet pipe 301. The flue gas inlet pipe 301 faces the filter cylinder 400. The flue gas can enter the inner cavity of the filter cylinder 400 through the filter holes on the filter cylinder 400. As the filter cylinder 400 rotates and changes position, the side of the filter cylinder 400 facing the flue gas maintains good air permeability as much as possible. The flue gas completes gas-solid separation stably. The slag trapped on the outer wall is centrifugally thrown out with the rotation of the cylinder and further scraped and collected by the material removal mechanism.

[0022] In this embodiment, specific reference is made. Figures 3-4 and Figures 6-7 As shown, the rotating mechanism includes a drive motor 500, which is fixed to the side wall of the pretreatment cylinder 300 by a bracket, and its output end is connected to a first synchronous pulley 501. A second synchronous pulley 502 is provided at the top of the connecting cylinder 401 near the top of the pretreatment cylinder 300, and a synchronous belt 503 is sleeved between the second synchronous pulley 502 and the first synchronous pulley 501.

[0023] The first synchronous pulley 501 is driven to rotate by the drive motor 500. The first synchronous pulley 501 drives the second synchronous pulley 502 to rotate synchronously through the synchronous belt 503. The second synchronous pulley 502 drives the connecting cylinder 401 to rotate on the pretreatment cylinder 300. With the help of the rotary joint, the connecting cylinder 401 rotates relative to the air inlet pipe 105, so that the connecting cylinder 401 drives the filter cartridge 400 to rotate stably inside the pretreatment cylinder 300.

[0024] The material removal mechanism is located inside the pretreatment cylinder 300, and it is configured to assist in separating the high-temperature slag from the outer wall of the filter cylinder 400 when the filter cylinder 400 rotates. In one specific embodiment of the present invention, such as Figures 7-10 As shown, the material removal mechanism includes a material removal plate 700 and several sets of elastic telescopic components 701; The material removal plate 700 is axially inclined between the inner side of the pretreatment cylinder 300 and the outer side of the filter cylinder 400, and the inner inclined arc surface of the material removal plate 700 is in contact with the outer wall of the filter cylinder 400. The outer side of the material removal plate 700 is connected to the inner wall of the pretreatment cylinder 300 through several sets of elastic telescopic members 701, and the elastic telescopic members 701 provide radial pre-tightening force so that the inner inclined arc surface of the material removal plate 700 is always in close contact with the outer wall of the filter cylinder 400 when the filter cylinder 400 rotates. The material removal plate 700 is inclined and has an overall arc structure, which can form an inclined arc surface to be attached to the outer wall of the filter cartridge 400 to better adapt to the curvature of the outer wall of the filter cartridge 400 and achieve a large range of arc surface contact. With the adaptive compensation of the outer elastic telescopic component 701, it can always be tightly attached to the outer wall of the filter cartridge 400, completely eliminating the scraping gap and preventing the phenomenon of missed scraping and dust accumulation. Meanwhile, the inclined arc surface forms a fixed downward slope. During the process of the filter cartridge 400 rotating and scraping off the high-temperature slag particles, the oblique shearing force of the arc surface can be used to improve the slag stripping effect. Moreover, the stripped high-temperature slag can slide down and collect quickly and smoothly along the arc plate surface, avoiding stagnation and accumulation on the surface of the descraper plate 700 or the filter cartridge 400. This ensures the continuous air permeability and filtration efficiency of the filter cartridge 400, guarantees the concentrated falling and collection of high-temperature slag, and provides a stable material foundation for the subsequent heat recovery of slag particles.

[0025] The elastic telescopic component 701 includes a support cylinder 7001 and a support rod 7002 that are interlocked. One end of the support cylinder 7001 is fixedly connected to the pretreatment cylinder 300, and a spring 7003 is fixedly installed inside it. One end of the support rod 7002 is fixedly connected to the spring 7003, and the other end is fixedly connected to the material removal plate 700.

[0026] The spring 7003 allows the support cylinder 7001 and the support rod 7002 to slide and retract relative to each other and return to their original positions. When the material removal plate 700 is subjected to force, it can act on the elastic telescopic member 701. The telescopic retraction and retraction of the elastic telescopic member 701 provides radial preload force, which acts in the opposite direction on the material removal plate 700, so that the inner side of the material removal plate 700 that is in contact with the filter cylinder 400 can always be pressed against the filter wall, thereby ensuring the scraping effect.

[0027] The second heat exchange unit is installed on the pretreatment cylinder 300 and is used to exchange heat with the high-temperature slag falling into the pretreatment cylinder 300. For details, please refer to the following: Figures 6-8 The second heat exchange unit includes: A heat exchange cylinder 600 is located at the bottom of the pretreatment cylinder 300. The bottom of the pretreatment cylinder 300 has a conical structure and is connected to a slag discharge pipe 302. The bottom end of the slag discharge pipe 302 extends outside the heat exchange cylinder 600 and is equipped with a control valve 303. A second water inlet pipe 601 is located above the side wall of the heat exchange cylinder 600 to introduce water into the heat exchange cylinder 600. A second water outlet pipe 602 is located below the side wall of the heat exchange cylinder 600 to discharge water from the heat exchange cylinder 600. High-temperature slag falls into the conical bottom of the pretreatment cylinder 300 under gravity, and a heat exchange medium is introduced into the heat exchange cylinder 600. The accumulated high-temperature slag heats the medium inside the heat exchange cylinder 600, realizing the recovery of the slag's own heat. The cooled slag can be discharged through the open slag discharge pipe 302, completing the solidification process.

[0028] like Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the waste heat recovery device for iron and steel smelting of the present invention further includes: The partition 800 includes several upper partitions 801 and several lower partitions 802. The upper partitions 801 are located at the top inside the main processing box 100, and the lower partitions 802 are located at the bottom inside the main processing box 100. The upper partitions 801 and lower partitions 802 are arranged alternately. The flow guide 102 is located above the inner cavity of the gas collection hood 101, and the top branch of the flow guide 102 is connected to the bottom of several lower partitions 802 respectively. The upper partition 801, the lower partition 802 and the flow guide 102 form multiple continuous zigzag flue gas flow paths in the main processing box 100. The heat exchange tube 200 is arranged longitudinally along the zigzag flue gas flow paths. Multiple continuous, zigzag flue gas flow paths are formed by the partition 800 and the guide frame 102. After the high-temperature flue gas enters the gas collection hood 101, it can continue to be guided to the two sets of zigzag flue gas flow paths on both sides. The high-temperature flue gas flows back and forth within these paths, passing sequentially through the heat exchange tubes 200 arranged longitudinally on the paths. This greatly extends the effective heat exchange path of the high-temperature flue gas, allowing it to act evenly with each heat exchange tube 200. This increases the residence time of the flue gas in the main treatment box 100, fully releasing the waste heat carried by the flue gas. Compared with the traditional straight-through flue gas flow structure, this effectively solves the problems of short flue gas flow paths, excessively fast flow rates, and insufficient heat exchange with the heat exchange tubes 200, greatly improving the waste heat recovery efficiency.

[0029] Several guide vanes 900 are arranged in a staggered manner on the outside of several heat exchange tubes 200 in the loop-shaped flue gas flow path.

[0030] Specifically by Figure 5It can be seen that the guide plate 900 includes an inner arc section and an outer arc section, and the distance between the tube wall of the heat exchange tube 200 and the inner arc section of the guide plate 900 gradually decreases along the flue gas forward direction.

[0031] Because the flue gas flow path is equipped with staggered guide plates 900, which are matched one-to-one with the heat exchange tubes 200, the inner arc section gradually narrows the flow distance between the guide plate 900 and the heat exchange tube 200 along the flue gas flow direction, forming a converging effect on the high-temperature flue gas. This forces the flue gas to adhere tightly to the outer wall of the heat exchange tube 200 and continuously scour the back side of the flow. The outer arc section can smoothly guide the flue gas and regulate the flow direction, thereby greatly enhancing the heat exchange effect between the high-temperature flue gas and the medium inside the heat exchange tube 200. This effectively avoids the problem of uneven and insufficient local heat exchange, and achieves efficient recovery of waste heat from high-temperature steel smelting flue gas.

[0032] like Figures 1-10 As shown, this invention provides a waste heat recovery method for a waste heat recovery device in steel smelting, comprising the following steps: First, the dust-laden hot flue gas generated during high-temperature steel smelting is continuously fed into the pretreatment cylinder 300 through the flue gas inlet pipe 301. A rotatable filter cylinder 400 is installed inside the pretreatment cylinder 300, which can be driven to rotate within the pretreatment cylinder 300 by a rotating mechanism. Then, under the action of negative pressure suction within the main treatment box 100, the high-temperature flue gas passes through the filter cylinder 400. The filter pores in the filter wall draw the flue gas into the inner cavity, where the slag (high-temperature dust particles) is trapped on the outer wall of the filter cartridge 400. The centrifugal force generated by the rotation of the filter cartridge 400 initially throws off the slag adhering to the outer wall. At the same time, the material removal mechanism scrapes and separates the slag from the outer wall of the filter cartridge 400. The scraped slag slides down the inclined arc plate surface, achieving downward concentration and guidance. Under the action of gravity, the separated high-temperature slag falls into the conical bottom of the pretreatment cylinder 300, forming a high-temperature slag accumulation layer at the bottom, which then flows towards the heat exchanger surrounding the bottom. A heat exchange medium (such as air or water) is introduced into the heat exchange cylinder 600. The medium inside the heat exchange cylinder 600 is heated by the accumulated high-temperature slag, realizing the recovery of waste heat from the solid particles. After the slag is cooled down by the heat exchange, it is discharged outward through the slag discharge pipe 302, completing the solidification process. At the same time, the high-temperature flue gas entering the filter cylinder 400 is introduced into the gas collection hood 101 through the connecting cylinder 401, and then splits into two sets of symmetrically arranged loop flue gas flow paths in the main treatment box 100, where the high-temperature flue gas flows back and forth. During the process, the flue gas flows sequentially through the longitudinally arranged heat exchange tubes 200 along the path. With the guidance of the staggered guide plates 900, the convective heat exchange between the high-temperature flue gas and the circulating water inside the heat exchange tubes 200 is enhanced, achieving efficient recovery of the high-temperature heat of the flue gas. Finally, after being cooled by heat exchange, the flue gas flows upward along the loop-shaped flue gas flow path and converges into the outlet pipe 103, from which it is discharged outward. It can then be connected to purification processes such as desulfurization, thus completing the entire waste heat recovery process.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0034] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A waste heat recovery device for iron and steel smelting, characterized in that, include: The main processing box (100) has an exhaust pipe (103) at its top and an air collection hood (101) at its bottom, and an air inlet pipe (105) at the bottom of the air collection hood (101). The first heat exchange unit is installed on the main processing box (100) and is used to exchange heat with the high-temperature steel smelting flue gas introduced into the main processing box (100); The pretreatment cylinder (300) is mounted below the gas collection hood (101) by a bracket, and its side wall is provided with a smoke inlet pipe (301). The filter cartridge (400) has a connecting cylinder (401) at its top end. The connecting cylinder (401) is movably connected to the top end of the pretreatment cartridge (300) through a bearing. The top end of the connecting cylinder (401) passes through the pretreatment cartridge (300) and is rotatably connected to the bottom end of the air inlet pipe (105) through a rotary joint. The pretreatment cartridge (300) is provided with a rotating mechanism for driving the connecting cylinder (401) to rotate. The material removal mechanism is disposed inside the pretreatment cylinder (300) and is configured to assist in separating the high-temperature slag from the outer wall of the filter cylinder (400) when the filter cylinder (400) rotates. The second heat exchange unit is disposed on the pretreatment cylinder (300) and is used to exchange heat with the high-temperature slag falling into the pretreatment cylinder (300).

2. The waste heat recovery device and method for iron and steel smelting according to claim 1, characterized in that, The first heat exchange unit includes: Several sets of heat exchange tubes (200) are arranged in an array inside the main processing box (100); Two water storage tanks (201) are symmetrically arranged at both ends of the main treatment tank (100), and the two ends of the heat exchange tube (200) are respectively connected to the two water storage tanks (201); One of the water storage tanks (201) is provided with a first water inlet pipe (202) at one end, and the other water storage tank (201) is provided with a first water outlet pipe (203) at one end.

3. The waste heat recovery device and method for iron and steel smelting according to claim 1, characterized in that, The second heat exchange unit includes: A heat exchange cylinder (600) is located at the bottom of the pretreatment cylinder (300). The bottom of the pretreatment cylinder (300) has a conical structure and is connected to a slag discharge pipe (302). The bottom of the slag discharge pipe (302) extends to the outside of the heat exchange cylinder (600) and is equipped with a control valve (303). The second water inlet pipe (601) is located above the side wall of the heat exchange cylinder (600) and is used to introduce water into the heat exchange cylinder (600); The second water outlet pipe (602) is located below the side wall of the heat exchange cylinder (600) and is used to discharge water from the heat exchange cylinder (600).

4. The waste heat recovery device and method for iron and steel smelting according to claim 1, characterized in that, The rotating mechanism includes a drive motor (500), which is fixed to the side wall of the pretreatment cylinder (300) by a bracket, and its output end is connected to a first synchronous pulley (501). A second synchronous pulley (502) is provided at the top of the connecting cylinder (401) near the top of the pretreatment cylinder (300), and a synchronous belt (503) is sleeved between the second synchronous pulley (502) and the first synchronous pulley (501).

5. The waste heat recovery device and method for iron and steel smelting according to claim 1, characterized in that, The material removal mechanism includes a material removal plate (700) and several sets of elastic telescopic components (701). The material removal plate (700) is axially inclined between the inner side of the pretreatment cylinder (300) and the outer side of the filter cylinder (400), and the inner inclined arc surface of the material removal plate (700) is in contact with the outer wall of the filter cylinder (400). The outer side of the material removal plate (700) is connected to the inner wall of the pretreatment cylinder (300) through several sets of elastic telescopic members (701), and the elastic telescopic members (701) provide radial pre-tightening force so that the inner inclined arc surface of the material removal plate (700) is always in close contact with the outer wall of the filter cylinder (400) when the filter cylinder (400) rotates.

6. The waste heat recovery device for iron and steel smelting according to claim 5, characterized in that, The elastic telescopic component (701) includes a support cylinder (7001) and a support rod (7002) that are interlocked. One end of the support cylinder (7001) is fixedly connected to the pretreatment cylinder (300), and a spring (7003) is fixedly installed inside it. One end of the support rod (7002) is fixedly connected to the spring (7003), and the other end is fixedly connected to the material removal plate (700).

7. The waste heat recovery device for iron and steel smelting according to claim 2, characterized in that, The waste heat recovery device for iron and steel smelting also includes: The partition (800) includes a plurality of upper partitions (801) and a plurality of lower partitions (802). The plurality of upper partitions (801) are located at the top inside the main processing box (100), and the plurality of lower partitions (802) are located at the bottom inside the main processing box (100). The upper partitions (801) and lower partitions (802) are arranged alternately. A flow guide (102) is disposed above the inner cavity of the gas collection hood (101), and the top branch of the flow guide (102) is connected to the bottom of several lower partitions (802). The upper partition (801), the lower partition (802) and the flow guide (102) form multiple continuous zigzag flue gas flow paths within the main processing box (100). The heat exchange tube (200) is arranged longitudinally along the zigzag flue gas flow paths. Several guide vanes (900) are arranged in a staggered manner on the outside of several heat exchange tubes (200) within the loop-shaped flue gas flow path.

8. The waste heat recovery device for iron and steel smelting according to claim 7, characterized in that, The guide plate (900) includes an inner arc segment and an outer arc segment, and the distance between the tube wall of the heat exchange tube (200) and the inner arc segment of the guide plate (900) gradually decreases along the flue gas forward direction.

9. The waste heat recovery device for iron and steel smelting according to claim 1, characterized in that, An exhaust fan (104) is installed inside the exhaust pipe (103).

10. A method for recovering waste heat from a waste heat recovery device in iron and steel smelting, characterized in that, The waste heat recovery device for iron and steel smelting as described in any one of claims 1-9 includes the following steps: S1. High-temperature steel smelting flue gas is fed into the pretreatment cylinder (300) through the flue gas inlet pipe (301); S2. The flue gas is drawn into the inner cavity through the filter holes of the filter cylinder (400). The slag in the flue gas is trapped on the outer wall of the filter cylinder (400). The filter cylinder (400) rotates around its own axis. The centrifugal force initially throws away the slag attached to the outer wall. At the same time, the material removal mechanism further scrapes and separates the slag on the outer wall of the filter cylinder (400) and guides the slag downward through its oblique arc guiding action. S3. Under the action of gravity, the high-temperature slag falls into the conical bottom of the pretreatment cylinder (300), and the heat exchange medium is introduced into the heat exchange cylinder (600). The accumulated high-temperature slag heats the medium in the heat exchange cylinder (600), thereby realizing the recovery of the heat of the slag itself. The cooled slag can be discharged outward through the open slag discharge pipe (302) to complete the solidification process. S4. The high-temperature flue gas entering the filter cartridge (400) is introduced into the gas collection hood (101) through the connecting tube (401), and then diverted into two sets of symmetrically arranged loop flue gas flow paths in the main treatment box (100). During the folding flow of the high-temperature flue gas in the main treatment box (100), it flows through the heat exchange tubes (200) arranged longitudinally on the path in sequence. With the convergence and guidance of the staggered guide plates (900), the convective heat exchange between the high-temperature flue gas and the circulating water in the heat exchange tubes (200) is enhanced, so as to realize the efficient recovery of the high-temperature heat of the gas. S5. After heat exchange and cooling, the gas flows upward along the loop-shaped flue gas flow path and converges into the gas outlet pipe (103), and is discharged outward through the gas outlet pipe (103), thus completing the waste heat recovery operation.

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