Secondary lead smelting high-temperature flue gas waste heat recycling device

Abstract

The invention discloses a secondary lead smelting high-temperature flue gas waste heat recycling device, and belongs to the technical field of waste heat recovery, the secondary lead smelting high-temperature flue gas waste heat recycling device comprises a vertical frame, an outer ring cylinder and a center cylinder concentrically arranged in the outer ring cylinder, and the bottom of the center cylinder is connected with a dust hopper for flue gas coarse dust removal; an annular cavity between the outer annular cylinder and the center cylinder forms a heat exchange water area, and multiple rows of heat exchange pipes are annularly arranged in the heat exchange water area. The core of the invention lies in that a three-stage heat exchange path is constructed, flue gas is settled in the central cylinder from bottom to top and subjected to primary heat exchange, and then flows through all heat exchange tubes from top to bottom and then from bottom to top in sequence, so that efficient cascade heat exchange is realized; steam generated by the system is creatively utilized to drive a turbine mechanism, shovel strips in all heat exchange pipes are driven to rotate synchronously, and online self-cleaning is achieved; the alkali spraying mechanism is arranged at the top of the central cylinder, acid gas is neutralized from the source, and corrosion is effectively prevented; according to the invention, the integration of sedimentation, deacidification, heat exchange and self-deashing is realized, and the problems of large occupied area, easiness in blockage, low efficiency and serious corrosion of a traditional system are solved.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery equipment technology, and specifically discloses a waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting. Background Technology

[0002] The widespread use of lead-acid batteries has generated a large amount of waste lead, making recycled lead smelting a crucial link in resource recycling. During the recycled lead smelting process, the smelting furnace produces a large amount of high-temperature flue gas. This flue gas not only carries considerable heat energy but also contains pollutants such as dust and acidic gases (e.g., SO2). Traditionally, the treatment of this type of flue gas typically employs a sequential process route of "pre-cooling tower + waste heat boiler + dust removal and acid desulfurization".

[0003] However, traditional methods have the following significant drawbacks: First, the system occupies a large area, with each functional unit (such as the pre-cooling tower, settling chamber, waste heat boiler, and purification tower) independently set up and connected by complex pipelines, resulting in high infrastructure costs, long heat loss paths, and limited waste heat recovery efficiency. Second, dust in the flue gas easily deposits in the heat exchange tube bundles of the waste heat boiler, causing a sharp drop in heat exchange efficiency or even pipeline blockage, requiring frequent shutdowns for manual cleaning or the use of expensive soot blowers, seriously affecting the continuity and economy of production. Third, the acidic gases in the high-temperature flue gas have a strong corrosive effect on metal heat exchange components. Although a deacidification tower is installed downstream, the flue gas is still in a high-temperature corrosive state when it enters the waste heat boiler, greatly shortening the service life of the heat exchange equipment. Traditional pre-cooling towers directly cool and remove acid by spraying alkaline liquid, which can protect downstream equipment, but the waste heat in the high-temperature flue gas cannot be utilized immediately, resulting in a large amount of high-quality heat energy being wasted and failing to achieve energy cascade and efficient recovery. Therefore, there is an urgent need in this field for an integrated device that can integrate flue gas pretreatment, waste heat recovery in stages and corrosion protection, in order to achieve efficient, stable and continuous waste heat recovery in a compact space. Summary of the Invention

[0004] The purpose of this invention is to provide a waste heat recovery and utilization device for high-temperature flue gas in recycled lead smelting, so as to solve the problems of large footprint, easy ash accumulation and blockage of heat exchange tubes, rapid decline in heat exchange efficiency, and severe corrosion of high-temperature acidic flue gas in the existing waste heat recovery system.

[0005] This invention is achieved through the following technical solution: A device for recovering and utilizing waste heat from high-temperature flue gas in recycled lead smelting includes a frame, in which a vertically arranged outer ring cylinder is fixed. Inside the outer ring cylinder, a central cylinder with a lower end extending outward and a dust collection hopper at the bottom is concentrically arranged. The lower end of the central cylinder is provided with an inlet pipe for introducing high-temperature flue gas, and the top of the outer ring cylinder is connected to an outlet pipe for discharging the high-temperature flue gas after heat exchange. The upper and lower annular tube sheets are respectively provided at the upper and lower ends of the annular gap between the outer annular tube and the central tube. Two rows of heat exchange tubes are arranged in an annular array between the upper and lower annular tube sheets, and both rows of heat exchange tubes are placed in the heat exchange water annular cavity formed between the upper and lower annular tube sheets. A partition annular plate is provided on the upper surface of the upper annular tube sheet, which divides the upper space into a radial inner circular cavity that communicates with the central tube and a radial outer annular cavity that communicates with the flue gas pipe. A rotating shaft is rotatably mounted on the upper surface of the outer annulus directly above each heat exchange tube. The lower end of the rotating shaft is connected to an arc-shaped shovel that extends into the corresponding heat exchange tube and fits against its inner wall. A gear is mounted on the upper end of the rotating shaft. A stepped gear disk that meshes with all the gears is mounted at the center of the upper surface of the outer annulus. The stepped gear disk is connected to the steam turbine drive assembly through a central rotating shaft. The steam turbine drive assembly is connected to the top of the heat exchange water annulus cavity through a steam duct.

[0006] As a further provision of the above scheme, the steam turbine drive assembly includes a steam turbine connected to the upper end of the central rotating shaft, and a turbine housing that matches and is fixedly installed with the steam turbine, and the turbine housing is provided with a steam inlet pipe and a steam outlet pipe.

[0007] As a further provision of the above scheme, the steam conduit is provided with a first branch pipe and a second branch pipe respectively connected to the steam inlet pipe and the steam outlet pipe. A first solenoid valve is provided on the first branch pipe, and a second solenoid valve is provided on the steam conduit between the first branch pipe and the second branch pipe.

[0008] As a further provision of the above scheme, a dust removal hopper is provided on the bottom wall of the outer ring cylinder, and a dust removal rotating ring is rotatably provided on the inner ring wall of the outer ring cylinder located below the lower annular tube plate. A scraper that fits against the bottom wall of the outer ring cylinder is provided in the dust removal rotating ring, and a power component for driving the dust removal rotating ring to rotate is provided on the outer ring cylinder.

[0009] As a further feature of the above scheme, the arc-shaped shovel is arranged to pass through the corresponding heat exchange tubes from top to bottom, and the side end of the arc-shaped shovel in the direction of rotation is arranged in a thin blade shape.

[0010] As a further provision of the above scheme, an alkali spraying treatment mechanism for neutralizing acidic gases in high-temperature flue gas is provided at the upper end of the inner cavity of the central cylinder. The alkali spraying treatment mechanism includes an annular spray pipe concentrically arranged inside the central cylinder. Several atomizing nozzles are provided on the lower surface of the annular spray pipe. The end of the annular spray pipe is connected to an alkaline solution source through a feed pipe.

[0011] As a further provision of the above scheme, a flue gas guide is provided directly below the annular nozzle. The flue gas guide includes a lower opening converging hood arranged concentrically with the central cylinder. The top opening of the lower opening converging hood is provided with a guide cone block that diffuses evenly in all directions.

[0012] As a further provision of the above scheme, the smoke inlet pipe extends laterally into the lower end of the inner cavity of the central cylinder, and the inner end of the smoke inlet pipe is vertically upward at the center of the central cylinder, and the diameter of the smoke inlet pipe is set between 1 / 4 and 1 / 3 of the diameter of the central cylinder.

[0013] As a further feature of the above scheme, the inner row of gears is set lower than the outer row of gears, and both the inner and outer rows of gears mesh with the stepped gear plate.

[0014] As a further provision of the above scheme, the lower ends of the dust collection hopper and the ash removal hopper are respectively provided with a first ash discharge gate valve and a second ash discharge gate valve.

[0015] The operation of the equipment described in this invention is a highly efficient and automated process integrating "gravity settling, alkali spraying for acid removal, three-stage heat exchange, and self-driven dust removal." Its core operating flow and principle are as follows: Flue gas introduction and primary treatment stage: The high-temperature flue gas from recycled lead smelting first enters the central cylinder vertically upwards from the inlet pipe located at the bottom of the equipment. Because the diameter of the central cylinder is much larger than the inlet pipe, the flue gas velocity decreases sharply. Most of the dust particles contained within the gas settle under gravity and then naturally fall into the dust collection hopper at the bottom, completing coarse dust removal. Simultaneously, the high-temperature flue gas comes into contact with the wall of the central cylinder, which serves as the heat exchange chamber, achieving the first heat exchange and transferring heat to the outer ring heat exchange water area.

[0016] Alkali spraying for acid removal and airflow distribution stage: After initial settling and one heat exchange, the high-temperature flue gas rises to the top of the central cylinder. At this point, the alkali spraying mechanism is activated, and the atomizing nozzles on the annular nozzle spray a fine alkaline solution downwards. The flue gas guide below directs the rising flue gas flow to the surrounding areas, ensuring thorough mixing and contact with the alkaline droplets. This effectively neutralizes the acidic gases in the flue gas, generating dry, solid salt powder, most of which settles directly. This process simultaneously completes "chemical acid removal" within the settling chamber, minimizing the corrosiveness of the flue gas and providing protection for the subsequent heat exchange tubes.

[0017] Two-stage convection and deep heat exchange: The treated flue gas enters the radial inner cavity separated by the upper annular tube sheet, and is then distributed into the inner row of heat exchange tubes, flowing from top to bottom and undergoing a strong second convection heat exchange with the water outside the tubes. Then, after the flue gas reaches the bottom of the equipment, the flow direction changes 180°, and it enters the outer row of heat exchange tubes, flowing from bottom to top, completing the third convection heat exchange.

[0018] Clean Gas Exhaust and Self-Cleaning Stage: The low-temperature flue gas, having completed the entire heat exchange process, ultimately flows into the radial outer annular cavity and exits the equipment through the exhaust pipe, destined for the subsequent flue gas treatment system. Simultaneously, when a decrease in heat exchange efficiency due to ash accumulation inside the tubes is detected, the self-driven ash removal system is activated (or can be activated periodically). Upon activation, a portion of the high-temperature steam generated by the equipment itself is introduced into the steam turbine drive assembly. The steam drives the turbine to rotate, which, through the central shaft and stepped gear disc, synchronously rotates the gears above all heat exchange tubes. This causes the arc-shaped scrapers extending into each heat exchange tube to rotate, effectively removing the accumulated ash from the inner wall of the tubes like a "razor," which then falls to the bottom. Finally, the bottom cleaning ring and scraper, driven by a motor, periodically operate to collect all the dust settled at the bottom of the equipment (including gravity-settled dust and dust collected during cleaning) into the cleaning hopper for unified discharge.

[0019] Compared with the prior art, the present invention has the following beneficial effects: The core of the waste heat recovery equipment disclosed in this invention lies in its unique flue gas flow path design. High-temperature flue gas first rises at a low speed within the central cylinder, completing the gravity settling of particulate impurities and undergoing a first radiative heat exchange with the central cylinder wall. Subsequently, the flue gas flows twice, first from top to bottom and then from bottom to top, through annularly arranged heat exchange tubes, undergoing secondary and tertiary convective heat exchange. This integrated design of "sedimentation + three-stage heat exchange" not only achieves efficient cascade recovery of waste heat but also eliminates the need for traditional pre-dust collectors and quench towers, making the entire equipment structure extremely compact. It fundamentally solves the problems of large footprint and long flue gas flow paths leading to severe heat loss in existing waste heat recovery systems.

[0020] The waste heat utilization equipment disclosed in this invention also features a self-driven ash removal system. This system cleverly utilizes the high-temperature steam generated during the equipment's operation as a power source to drive the steam turbine to rotate. This, in turn, drives the arc-shaped scrapers inside all the heat exchange tubes to rotate synchronously via gear transmission, thereby automatically removing the attached ash online. This ash removal system design eliminates the need for external power, effectively preventing severe scaling and blockage of the heat exchange tubes. It ensures long-term stability of heat exchange efficiency and continuous equipment operation, solving the problems of frequent maintenance and reduced heat exchange efficiency caused by ash accumulation in traditional waste heat boilers.

[0021] This invention also integrates an atomized alkali spraying system at the top of the settling chamber (i.e., the central cylinder). This system effectively neutralizes acidic gases in the high-temperature flue gas after primary heat exchange and particle settling, and before it enters the main heat exchange zone (i.e., secondary and tertiary heat exchange). Furthermore, it fully absorbs radiant heat from the high-temperature flue gas during the settling process before neutralization. Compared to installing an atomized alkali spraying system at the front end of the equipment, this design not only fully utilizes the waste heat of the high-temperature flue gas immediately, but also allows for a more compact overall equipment structure and controls the harmful effects of corrosive gases at the source. This significantly extends the service life of the core components (i.e., the heat exchange tubes) and improves the overall durability and economy of the equipment. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a three-dimensional structural diagram of the present invention from a first angle; Figure 2 This is a schematic diagram of the second-angle three-dimensional structure of the present invention; Figure 3 This is a schematic diagram of the three-dimensional structure of the outer ring cylinder, turbine housing, stepped gear disk, etc. in this invention; Figure 4 This is a schematic diagram of the internal three-dimensional structure of the outer ring cylinder and the central cylinder in this invention. Figure 5 This is a top view of the outer ring cylinder after the top wall has been removed, which is a schematic diagram of the structure in this invention. Figure 6 This is a three-dimensional structural diagram of the heat exchange tube, upper annular tube sheet, and lower annular tube sheet in this invention. Figure 7 This is a three-dimensional structural diagram of the rotating shaft, arc-shaped shovel, gears, etc. in this invention. Figure 8 This is a schematic diagram of the three-dimensional cross-sectional structure of the turbine housing, stepped gear disk, etc. in this invention; Figure 9 This is a three-dimensional structural diagram of the dust removal rotating ring, power assembly, and scraper in this invention; Figure 10 For the present invention Figure 4 A magnified structural diagram of point A in the middle. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The following will refer to the appendix... Figures 1-10 This application will be described in detail with reference to the embodiments. Example 1

[0026] Example 1 discloses a device for recovering and utilizing waste heat from high-temperature flue gas in recycled lead smelting, as shown in the attached document. Figures 1-6 The main body of the equipment includes a frame 1, inside which a vertically arranged outer ring cylinder 2 is fixedly installed. Inside the outer ring cylinder 2, a downwardly extending central cylinder 3 is concentrically arranged. The central cylinder 3 extends out of the bottom of the outer ring cylinder 2 and is connected to a dust collection hopper 301. A first ash gate valve 302 is installed at the bottom of the dust collection hopper 301. A flue gas outlet pipe 4 is provided at the top of the outer circular surface of the outer ring cylinder 2. One end of the flue gas outlet pipe 4 is arc-shaped and is uniformly connected to the upper end of the inner cavity of the outer ring cylinder 2. Then, the end of the flue gas outlet pipe 4 is connected to subsequent flue gas treatment equipment (such as an electrostatic precipitator, desulfurization and denitrification tower lamp). A flue gas inlet pipe 5 is provided at the lower end of the central cylinder 3, extending laterally into the lower end of its inner cavity. The flue gas inlet pipe 5 is vertically upward at the center of the central cylinder 3. The diameter of the flue gas inlet pipe 5 is set between 1 / 4 and 1 / 3 of the diameter of the central cylinder 3. Finally, the inlet end (i.e., the outer end) of the flue gas inlet pipe 5 is connected to the exhaust port of the recycled lead smelting furnace through a pipe, so that the high-temperature flue gas generated in the smelting furnace can be directly introduced into the interior of the central cylinder 3.

[0027] Upper annular tube sheet 6 and lower annular tube sheet 7 are respectively installed at the upper and lower ends of the annular gap between the outer annular tube sheet 2 and the central tube sheet 3. The annular gap between the upper annular tube sheet 6 and the lower annular tube sheet 7 forms a heat exchange water annular cavity, and two rows of heat exchange tubes 8 arranged in an annular array are connected between the upper annular tube sheet 6 and the lower annular tube sheet 7. Water inlet pipe 201 and water outlet pipe 202 are respectively installed at the upper and lower ends of the outer surface of the outer annular tube sheet 2, which are connected to the heat exchange water annular cavity. Low temperature water can be injected into the heat exchange water annular cavity or high temperature water after boiling can be discharged through the water inlet pipe 201 and water outlet pipe 202 for heat recovery and utilization. In addition, a partition annular plate 601 is installed on the upper surface of the upper annular tube sheet 6. The partition annular plate 601 is concentrically arranged between the two rows of annular tube sheets 6, thereby dividing the space above the upper annular tube sheet 6 into a radial inner cavity and a radial outer annular cavity. The top of the central tube sheet 3 is connected to the radial inner cavity, and the flue pipe 4 is connected to the radial outer annular cavity.

[0028] In the process of utilizing the waste heat of high-temperature flue gas in recycled lead smelting, after the high-temperature flue gas enters the lower end of the central cylinder 3 through the inlet pipe 5, the upward flow velocity of the high-temperature flue gas along the central cylinder 3 is greatly reduced because the diameter of the central cylinder 3 is much larger than the diameter of the inlet pipe 5. Therefore, a large number of dust particles mixed in the high-temperature flue gas will settle under the action of gravity and eventually be deposited in the dust collection hopper 301. At the same time, as the high-temperature flue gas slowly moves upward along the central cylinder 3, it also undergoes a heat exchange with the low-temperature water in the heat exchange water ring cavity, realizing the first absorption of the waste heat of the high-temperature flue gas. After the dust has settled, the high-temperature flue gas flows into the radial inner cavity from the top opening of the central cylinder 3, and then moves downward along a row of heat exchange tubes 8 on the inner side, where it undergoes a secondary heat exchange with the low-temperature water in the heat exchange water ring cavity. After the secondary heat exchange, the high-temperature flue gas enters the annular space below the lower annular tube sheet 7 and moves upward along the outer row of heat exchange tubes 8. During this process, it will also undergo three heat exchanges with the low-temperature water in the heat exchange water annular cavity. Finally, it enters the radial outer annular cavity and is discharged by the flue gas outlet pipe 4.

[0029] Reference Appendix Figure 3 Appendix Figure 7 and attached Figure 8 Two rows of sealed bearings arranged in a ring array are provided on the upper surface of the outer ring cylinder 2, and the sealed bearings are aligned vertically with the heat exchange tubes 8. A rotating shaft 9 is rotatably mounted in each sealed bearing. A column block 10 is connected to the lower end of the rotating shaft 9, and an arc-shaped spade 11 extends into the corresponding heat exchange tube 8 and fits against its inner wall. The arc-shaped spade 11 extends through the entire heat exchange tube 8, and its side end in the direction of rotation is designed with a thin blade. A gear 12 is provided at the upper end of each rotating shaft 9 extending out of the sealed bearing, and the gears 12 on the inner row of rotating shafts 9 are all positioned lower than the gears on the outer row of rotating shafts 9.

[0030] A central rotating shaft 13 is rotatably mounted at the center of the upper surface of the outer annular cylinder 2. A stepped gear disk 14, which meshes with both inner and outer rows of gears 12, is mounted on the central rotating shaft 13. A steam turbine 15 is mounted on the central rotating shaft 13 above the stepped gear disk 14. A top plate 16 is fixed above the outer annular cylinder 2. A turbine housing 17, matching the steam turbine 15, is fixedly mounted at the center of the lower surface of the top plate 16. A steam inlet pipe 171 and a steam outlet pipe 172 are mounted on the turbine housing 17, so that high-temperature steam can drive the steam turbine 15, the central rotating shaft 13, and the stepped gear disk 14 to rotate after entering the turbine housing 17 through the steam inlet pipe 171, and then be discharged from the steam outlet pipe 172.

[0031] A steam conduit 18 is provided at the upper end of the outer annular cylinder 2, which is connected to the top of the heat exchange water annular cavity. A first branch pipe 181 and a second branch pipe 182 are provided at the side end of the steam conduit 18, which are respectively connected to the steam inlet pipe 171 and the steam outlet pipe 172. A first solenoid valve 183 is provided on the first branch pipe 181, and a second solenoid valve 184 is provided between the first branch pipe 181 and the second branch pipe 182. By controlling the first solenoid valve 183 to open and the second solenoid valve 184 to close, the steam conduit 18 can be introduced into the turbine housing 17 to drive the steam turbine 15 to rotate; otherwise, the high-temperature steam introduced into the steam conduit 18 will not pass through the turbine housing 17.

[0032] Reference Appendix Figure 4 and attached Figure 9 One or two dust removal hoppers 19 are provided on the bottom wall of the outer annular cylinder 2, and a second row of dust gate valves are provided at the bottom of the dust removal hoppers 19. Simultaneously, a dust removal rotating ring 20 is rotatably installed on the inner annular wall of the outer annular cylinder 2 below the lower annular tube plate 7. A scraper 21 that fits against the bottom wall of the outer annular cylinder 2 is provided in the dust removal rotating ring 20. A power assembly 22 for driving the rotation of the dust removal rotating ring 20 is also provided on the outer annular cylinder 2. In a specific design, the power assembly 22 includes a dust removal motor, with a transmission gear extending into the outer annular cylinder 2 on the output shaft of the dust removal motor. Ring teeth that mesh with the transmission gear are also provided on the outer circumference of the dust removal rotating ring 20.

[0033] In this embodiment 1, through the above structural design, during the process of recovering and utilizing the waste heat of high-temperature flue gas from recycled lead smelting, the high-temperature flue gas first moves slowly from bottom to top along the central cylinder 3 and exchanges heat with the water in the heat exchange water ring cavity once. During this process, particulate impurities are settled by gravity. Then, it moves from top to bottom along the inner row of heat exchange tubes 8 and exchanges heat with the water in the heat exchange water ring cavity a second time. Then, it moves from bottom to top along the outer row of heat exchange tubes 8 and exchanges heat with the water in the heat exchange water ring cavity a third time. Finally, it is discharged from the flue gas outlet pipe 4.

[0034] Meanwhile, when there are many impurities adhering to the inner wall of the heat exchange tube 8, or even when blockage occurs, the first solenoid valve 183 and the second solenoid valve 184 are actively controlled to operate. This allows the high-temperature steam generated in the heat exchange water ring cavity to flow through the turbine housing 17 and act on the steam turbine 15. Then, it drives the stepped gear disk 14 to rotate through the central rotating shaft 13. During the rotation of the stepped gear disk 14, it acts on all gears 12 simultaneously. During the rotation of the gears 12, all the arc-shaped scrapers 11 rotate around their central axis in the corresponding heat exchange tube 8, thereby scraping off the impurities and dirt on the inner wall of the heat exchange tube 8 through the arc-shaped scrapers 11, ensuring the heat exchange effect of the heat exchange tube 8.

[0035] Finally, the power unit 22 is started periodically. The transmission gear and the ring teeth of the cleaning ring 20 are meshed to make the cleaning ring 20 rotate on the inner wall of the outer ring cylinder 2 below the annular tube plate 7. The scraper 21 scrapes the dust and impurities that fall on the bottom wall of the outer ring cylinder 2 into the cleaning hopper 19. Then the second ash gate valve is opened to discharge them. Example 2

[0036] Example 2 discloses a waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting, which is an improved design based on the technical solution in Example 1. The similarities between Example 2 and Example 1 will not be described again.

[0037] To mitigate the acid corrosion of heat exchange tubes 8 caused by high-temperature flue gas from recycled lead smelting, corrosion-resistant alloy materials are prioritized for heat exchange tubes 8, and an alkali spraying treatment mechanism is installed at the top of the central cylinder 3.

[0038] For specific information on alkali spraying treatment organizations, please refer to the attached document. Figure 4 and attached Figure 10 It includes an annular nozzle 23 concentrically positioned at the upper end of the inner cavity of the central cylinder 3, with multiple atomizing nozzles 231 evenly arranged on the lower surface of the annular nozzle 23. A feed pipe 24 extending from the central cylinder 3 and the outer annular cylinder 2 is connected to the end of the annular nozzle 23. The outer end of the feed pipe 24 is then connected to an alkaline solution (not shown in the figure) via a feed pump, so that the alkaline solution can be evenly atomized and sprayed from the atomizing nozzles 231 during the operation of the feed pump, thereby contacting the high-temperature flue gas during the rising process, neutralizing the acidic gases in the high-temperature flue gas, and generating dry, powdery solid salt that then settles into the dust collection hopper 301.

[0039] Furthermore, in this embodiment 2, a flue gas guide 25 is provided directly below the annular nozzle 23. This flue gas guide 25 includes a lower-opening converging hood 251 concentrically positioned with the central cylinder 3. The top opening of the lower-opening converging hood 251 has a guide cone 252 that diffuses evenly in all directions. This allows the upward-flowing high-temperature flue gas to first gather at the top of the lower-opening converging hood 251, and then diffuse evenly outwards from the top of the lower-opening converging hood 251, ensuring that the sprayed atomized alkaline solution can fully contact the high-temperature flue gas. The lower-opening converging hood 251 is fixedly connected to the outer annular cylinder 2 via multiple radial connecting rods 253 in the circumferential direction. The maximum diameter of the lower end of the lower-opening converging hood 251 is set at approximately 4 / 5 of the inner diameter of the outer annular cylinder 2, allowing the annular gap between the two to smoothly discharge the generated solid salt particles.

[0040] In this embodiment 2, through the above design, after the high-temperature flue gas enters the central cylinder 3, the high-temperature flue gas slows down. On the one hand, it undergoes a full heat exchange with the heat exchange medium in the heat exchange water ring cavity through the central cylinder 3; on the other hand, it achieves effective settling of dust particles in the flue gas. Then, the high-temperature flue gas is guided by the flue gas guide 25 and diffuses evenly in all directions, and fully contacts the alkaline water mist sprayed by the atomizing nozzle 231, achieving neutralization of acidic gases in the high-temperature flue gas. Although the temperature of the neutralized high-temperature flue gas is reduced before the second and third heat exchanges (from about 300°C to about 220~250°C), it effectively solves the problem of frequent equipment failures caused by acidic gases easily corroding the heat exchange tubes, and improves the operational stability of the entire waste heat utilization equipment.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for recovering and utilizing waste heat from high-temperature flue gas in recycled lead smelting, comprising a vertical frame, characterized in that, The frame is fixed with a vertically arranged outer ring cylinder. Inside the outer ring cylinder, a central cylinder with a dust collection hopper at the bottom is concentrically arranged. The lower end of the central cylinder is provided with a flue gas inlet pipe for introducing high-temperature flue gas. The top of the outer ring cylinder is connected with a flue gas outlet pipe for discharging the high-temperature flue gas after heat exchange. The upper and lower annular tube sheets are respectively provided at the upper and lower ends of the annular gap between the outer annular tube and the central tube. Two rows of heat exchange tubes are arranged in an annular array between the upper and lower annular tube sheets, and both rows of heat exchange tubes are placed in the heat exchange water annular cavity formed between the upper and lower annular tube sheets. A partition annular plate is provided on the upper surface of the upper annular tube sheet, which divides the upper space into a radial inner circular cavity that communicates with the central tube and a radial outer annular cavity that communicates with the flue gas pipe. A rotating shaft is rotatably mounted on the upper surface of the outer annulus directly above each heat exchange tube. The lower end of the rotating shaft is connected to an arc-shaped shovel that extends into the corresponding heat exchange tube and fits against its inner wall. A gear is mounted on the upper end of the rotating shaft. A stepped gear disk that meshes with all the gears is mounted at the center of the upper surface of the outer annulus. The stepped gear disk is connected to the steam turbine drive assembly through a central rotating shaft. The steam turbine drive assembly is connected to the top of the heat exchange water annulus cavity through a steam duct.

2. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 1, characterized in that, The steam turbine drive assembly includes a steam turbine connected to the upper end of the central shaft, and a turbine housing that is matched and fixedly installed with the steam turbine. The turbine housing is provided with a steam inlet pipe and a steam outlet pipe.

3. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 2, characterized in that, The steam conduit is provided with a first branch pipe and a second branch pipe that are respectively connected to the steam inlet pipe and the steam outlet pipe. A first solenoid valve is provided on the first branch pipe, and a second solenoid valve is provided on the steam conduit between the first branch pipe and the second branch pipe.

4. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 1, characterized in that, A dust removal hopper is provided on the bottom wall of the outer ring cylinder, and a dust removal rotating ring is rotatably arranged on the inner ring wall of the outer ring cylinder located below the lower annular tube plate. A scraper that fits against the bottom wall of the outer ring cylinder is provided in the dust removal rotating ring, and a power component for driving the dust removal rotating ring to rotate is provided on the outer ring cylinder.

5. The device for recovering and utilizing waste heat from high-temperature flue gas in recycled lead smelting according to claim 1, characterized in that, The arc-shaped shovel is designed to penetrate the corresponding heat exchange tubes from top to bottom, and the side end of the arc-shaped shovel in the direction of rotation is designed with a thin blade shape.

6. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 1, characterized in that, The upper end of the inner cavity of the central cylinder is provided with an alkali spraying treatment mechanism for neutralizing acidic gases in high-temperature flue gas. The alkali spraying treatment mechanism includes an annular spray pipe concentrically arranged inside the central cylinder. Several atomizing nozzles are provided on the lower surface of the annular spray pipe. The end of the annular spray pipe is connected to an alkaline solution source through a feed pipe.

7. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 6, characterized in that, A flue gas guide is provided directly below the annular nozzle. The flue gas guide includes a lower opening concentrator hood arranged concentrically with the central cylinder. The top opening of the lower opening concentrator hood is provided with a guide cone block that diffuses evenly in all directions.

8. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 1, characterized in that, The smoke inlet pipe extends laterally into the lower end of the inner cavity of the central cylinder, and the inner end of the smoke inlet pipe is vertically upward at the center of the central cylinder. The diameter of the smoke inlet pipe is set between 1 / 4 and 1 / 3 of the diameter of the central cylinder.

9. The waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 1, characterized in that, The inner row of gears is positioned lower than the outer row of gears, and both rows of gears mesh with the stepped gear plate.

10. A waste heat recovery and utilization device for high-temperature flue gas from recycled lead smelting according to claim 4, characterized in that, The lower ends of the dust collection hopper and the ash removal hopper are respectively equipped with a first ash discharge gate valve and a second ash discharge gate valve.

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