High-temperature flue gas quenching type waste heat boiler and waste heat recovery method applying same

Abstract

The high-temperature flue gas quenching type waste heat boiler comprises a main flue gas inlet pipe, a main flue gas outlet pipe and a boiler body fixedly arranged between the main flue gas inlet pipe and the main flue gas outlet pipe, and the input end and the output end of the boiler body are connected and communicated with the main flue gas inlet pipe and the main flue gas outlet pipe correspondingly. A plurality of dry ice descaling devices are further fixedly arranged on the main smoke outlet pipe, and the dry ice descaling devices and the boiler body are located on the same axis. The boiler body comprises a bundling sleeve, an upper pipe header and a lower pipe header, the upper pipe header and the lower pipe header are fixedly arranged at the two ends of the bundling sleeve respectively, the upper pipe header and the lower pipe header are communicated with an internal gap of the bundling sleeve, and an inlet section and an outlet section which are communicated with the main smoke inlet pipe and the main smoke outlet pipe respectively are fixedly arranged at the two ends of the bundling sleeve. By means of the bundling sleeve arranged in the boiler body, high-temperature flue gas and cooling water are located in different areas in the bundling sleeve, heat exchange is completed, flue gas waste heat of the high-temperature flue gas is effectively recycled, and the mixing condition of the cooling water and the flue gas is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of energy-saving and environmental protection equipment, and in particular to a high-temperature flue gas rapid cooling type waste heat boiler and a waste heat recovery method using the same. Background Art

[0002] In recent years, air quality issues have attracted great attention from the whole society. As a major industrial emitter, the steel industry is subject to increasingly strict restrictions on its emission standards and emissions.

[0003] China's steel industry is in a period of structural adjustment, optimization and upgrading. Facing increasingly severe resource and environmental pressures, it must take the path of sustainable development that is resource-saving, environmentally friendly and must be developed.

[0004] As the main steelmaking process of steel enterprises, converter steelmaking produces gas mainly containing carbon monoxide, a small amount of carbon dioxide and other trace components during the blowing process, which also carries a large amount of iron oxide, metal iron particles, and other fine particles of solid dust, which seriously pollutes the atmosphere and workshop environment. Therefore, improving the technical level of converter dust removal system, recycling and utilizing converter gas and recovering flue gas waste heat are of great significance for energy saving and consumption reduction in steelmaking, effectively controlling and reducing the emission of atmospheric pollutants in steelmaking, and reducing environmental pollution.

[0005] The temperature of converter flue gas outlet is about 1400-1600℃, and the dust concentration is 70-200g / m 3 After leaving the furnace, the gas is usually cooled to 800-1000℃ by vaporization cooling flue or water cooling flue, and then enters the flue gas dust removal system to reduce the dust concentration to meet the national emission standards and the requirements of gas users. At present, the domestic converter primary flue gas dust removal processes mainly include traditional OG method, new OG method, semi-dry method, and dry method (LT method).

[0006] At present, no matter which of the above-mentioned process systems is used for primary flue gas purification of converters, the common feature is that the high-temperature flue gas is cooled by absorbing the latent heat of vaporization through the evaporation of water. The dry method (LT method) dust removal also consumes a lot of steam due to the requirements of its own system. Although cooling the flue gas by consuming water is an efficient cooling method, it is a very energy-consuming method. Because the high-temperature flue gas coming out of the vaporization cooling flue itself is a kind of high-grade thermal energy, not only is there no way to recover the heat energy it carries, but a lot of other energy is also consumed to cool it, resulting in a lot of energy waste, which is also the main reason for the formation of smoke plumes. For example, under general design conditions, the flue gas temperature coming out of the vaporization flue is 800-1000℃. If the flue gas temperature is simply reduced to 500℃, 20kg of steam can be generated per ton of steel, which can generate huge benefits. And because the flue gas is cooled by spraying water and steam, a large amount of water is contained in the flue gas, which causes corrosion of the flue gas pipeline, the plate and shell of the electrostatic precipitator, the gas pipeline, and the gas recovery equipment.

[0007] In my country, the total amount of dioxins emitted from steel smelting accounts for about 45% of the total dioxin emissions in the country each year, making it one of the main emission sources. Electric furnace dust is metal dust volatilized during the heating process of metal, including metal and metal oxides. Its type is related to many factors such as the composition of the charge, oxide materials and oil-impregnated substances, smelting speed, furnace temperature, and oxygen blowing intensity. Electric furnace dust has the characteristics of small dust particles, high temperature, and high toxicity (containing toxic substances such as dioxins / furans / heavy metals). If effective control measures are not taken, it will seriously pollute the workshop and factory environment and affect the health of workers and surrounding residents.

[0008] The generation mechanism of dioxins in the electric furnace smelting process is as follows:

[0009] ⑴ Generation by chemical reaction: Grease, paint, coatings, plastics, etc. brought into the scrap steel contain dioxins and dioxin precursors, which will directly react to generate dioxins during the scrap steel preheating process. The reaction temperature range is 300-500℃.

[0010] (2) Generation by thermal decomposition reaction: During the preheating of scrap steel or electric furnace smelting, chlorine-containing polymer compounds decompose into dioxins through combustion / pyrolysis reaction, and the reaction temperature ranges from 500 to 800°C.

[0011] ⑶ De novo synthesis: During the smelting process, when the temperature exceeds 800°C, dioxins will be completely decomposed. However, during the process of flue gas cooling, dioxins will be regenerated through elementary reactions, and the reaction temperature range is 300-500°C.

[0012] The dioxins generated by the above three pathways flow with the flue gas through the combustion settling chamber, mechanical air cooler or evaporative cooler and other cooling devices in sequence, and gradually cool down in the dust removal pipeline, and are finally discharged into the chimney through the bag dust collector.

[0013] Because the dust particles in the flue gas of the electric furnace are small, with a diameter of about 40 to 300 meshes, dust of this size can only be collected by a bag filter to meet the emission standards. However, during the smelting stage of the electric furnace, the temperature in the high-temperature flue is as high as 1200°C. Even after cooling down the flue of the commonly used dust collector, the flue gas will still have a temperature of 500°C to 800°C before entering the dust collector. Obviously, this temperature exceeds the operating temperature allowed by the currently commonly used pulse-jet chemical fiber bag (chemical fiber cartridge) dust collector, so the requirements for the dust collector are very high, and the emission does not meet the environmental protection standards.

[0014] For filtering high-temperature flue gas, the pulse-jet chemical fiber bag type (chemical fiber cartridge type) dust collector filter bag (or metal flexible membrane cartridge) is usually used. The long-term operating environment generally requires the high-temperature flue gas temperature to be reduced to ≤200℃~250℃.

[0015] The widely used electric furnace flue gas purification process is: the high-temperature flue gas from the electric furnace is preheated in the scrap steel preheating channel, and the outlet temperature is 800-1000℃. It is directly cooled in the evaporative cooling tower with water spraying through the connecting flue and the combustion settling chamber, and the flue gas temperature is reduced to ≤250℃ and mixed with the flue gas captured from the electric furnace closed hood. It enters the bag filter and is discharged into the atmosphere through the fan and chimney after filtration and purification. The core point of this process technology is: the high-temperature flue gas is quickly cooled by spraying a large amount of water, thereby avoiding the rapid synthesis temperature range of dioxins (i.e., the temperature range of 250-450℃). The shortcomings of this process technology are mainly manifested in the following aspects:

[0016] ① Failure to effectively recover the flue gas waste heat of 800-250℃, resulting in waste of heat from the flue gas of the electric furnace;

[0017] ②A large amount of water spraying is required for cooling, which wastes cooling water;

[0018] ③ It is impossible to completely avoid dioxin synthesis, and de novo synthesis of dioxins will still occur during the subsequent cooling process;

[0019] ④ In addition, the use of "flow-injected activated carbon fine powder as adsorbent" to adsorb dioxins in the flue gas of the electric furnace makes the collected electric furnace dust contain a large amount of dioxins, and the electric furnace dust needs to be treated by hazardous waste methods, resulting in a waste of resources;

[0020] ⑤ During the cooling process, the cooling water will turn into water vapor and mix into the flue gas, significantly increasing the flue gas flow rate. On the one hand, the water in the flue gas can easily cause the bag filter to become sticky. On the other hand, the larger flue gas flow rate also increases the load on the fan and causes the "smoke plume" problem. Summary of the invention

[0021] The technical problem to be solved by the present invention is to overcome the defects of the prior art. The present invention proposes a high-temperature flue gas rapid cooling waste heat boiler and a waste heat recovery method using the same, which can effectively recover the flue gas waste heat of 800-250°C while avoiding the mixing of cooling water and flue gas and the use of adsorbents.

[0022] In order to solve the above technical problems, the technical solution adopted by the present invention is: a high-temperature flue gas rapid cooling type waste heat boiler, comprising a main smoke inlet pipe, a main smoke outlet pipe and a boiler furnace body fixedly arranged between the main smoke inlet pipe and the main smoke outlet pipe, the input end and the output end of the boiler furnace body are respectively connected to the main smoke inlet pipe and the main smoke outlet pipe, and a plurality of dry ice descaling devices are fixedly arranged on the main smoke outlet pipe, and the dry ice descaling devices and the boiler furnace body are located on the same axis;

[0023] The boiler furnace body includes a cluster sleeve and an upper pipe header and a lower pipe header respectively fixedly arranged at the two ends of the cluster sleeve, the upper pipe header and the lower pipe header are communicated with the internal gap of the cluster sleeve, and an inlet section and an outlet section respectively connected to the main smoke inlet pipe and the main smoke outlet pipe are fixedly arranged at the two ends of the cluster sleeve.

[0024] Furthermore, the cluster sleeve includes an outer tube and an inner tube, a distance rib plate is fixedly arranged between the outer tube and the inner tube, the inlet section and the outlet section are connected and penetrated with the two ends of the inner tube through a nozzle; a water inlet is opened on the lower tube header, and a drain outlet is opened on the upper tube header; the lower tube header and the upper tube header are fixedly arranged between the cluster sleeve and the water inlet / outlet based on the outer edge surface of the nozzle, and are penetrated with the gap between the outer tube and the inner tube.

[0025] Furthermore, refractory brickwork is fixedly arranged in the inlet section and the outlet section.

[0026] Furthermore, the dry ice descaling device includes a base, a guide rail frame, a driving device and an injection head, the guide rail frame is fixedly arranged on the base, the injection head is fixedly arranged below the driving device and is regulated by the driving device to reciprocate along the length direction of the guide rail frame.

[0027] Furthermore, a dry ice descaling rod is included, the driving device is fixedly arranged at one end of the dry ice descaling rod, the injection head is fixedly arranged at the other end of the dry ice descaling rod, and the driving device drives the rotation of the injection head with the dry ice descaling rod.

[0028] Furthermore, a dry ice blasting sending device is also included, and a sending channel is opened in the dry ice descaling rod along its length direction, one end of the sending channel is connected to the output end of the dry ice blasting sending device, and the other end is connected to the input end of the spray head.

[0029] Furthermore, a plurality of cooling water channels are provided in the dry ice descaling rod, and the water inlet and the water outlet of the cooling water channel are fixedly provided on the driving device.

[0030] Furthermore, the outer diameter of the dry ice descaling rod is smaller than the inner diameter of the inner tube.

[0031] Furthermore, there are multiple boiler furnace bodies and dry ice descaling devices, and the multiple boiler furnace bodies and dry ice descaling devices are fixedly arranged based on the length direction of the main smoke inlet pipe and the main smoke outlet pipe;

[0032] The width of the main smoke inlet pipe gradually decreases on the side away from the smoke inlet port, a nitrogen cleaning device is fixedly arranged below the main smoke inlet pipe, and an ash hopper is fixedly arranged below the main smoke inlet pipe close to the smoke inlet port;

[0033] The width of the main smoke outlet pipe gradually decreases on the side away from the smoke outlet. The dry ice descaling device is fixedly arranged on the upper surface of the main smoke outlet pipe with a partition valve. A soot blowing device is also fixedly arranged on the upper surface of the main smoke outlet pipe close to the partition valve.

[0034] Furthermore, a high-temperature flue gas waste heat recovery method is provided, which uses a high-temperature flue gas rapid cooling waste heat boiler to complete the waste heat recovery of the high-temperature flue gas. Specifically, after the input high-temperature flue gas is diverted to multiple separate heat exchange carriers, a low-temperature medium is input into the multiple heat exchange carriers to complete the heat exchange process with the high-temperature flue gas in the heat exchange carriers and then merged and discharged.

[0035] Compared with the prior art, the beneficial effects of the present invention include:

[0036] 1) Through the clustered sleeves arranged in the boiler body, the high-temperature flue gas and the cooling water are located in different areas of the clustered sleeves and complete the heat exchange, which effectively recovers the flue gas waste heat of the high-temperature flue gas without causing heat waste of the high-temperature flue gas. In addition, there is no contact between the high-temperature flue gas and the cooling water during the heat exchange process, so that during the flue gas cooling process, even if the cooling water is gasified, it will not mix with the flue gas, thereby effectively avoiding the "smoke plume" problem;

[0037] 2) By completing the rapid cooling process of the high-temperature flue gas input into the rapid cooling waste heat boiler in the form of split flow, the heat exchange efficiency of the rapid cooling process can be effectively enhanced compared to rapid cooling of the entire high-temperature flue gas input;

[0038] 3) By providing a dry ice descaling device to remove the ash deposited inside the boiler body, the ash deposited on the inner wall of the inner tube can be removed efficiently. The removal process does not involve harmful emissions and moisture, and no residue is left on the inner wall of the inner tube. The soot blowing device and the nitrogen purge device are used to remove the nozzles at both ends of the cluster sleeve, which can effectively enhance the heat exchange efficiency during the heat exchange process of the high-temperature flue gas.

[0039] 4) The nozzles arranged at both ends of the clustered sleeve can decelerate the high-temperature flue gas entering the inner tube of each sleeve, so that the temperature field in the tube is evenly distributed, so as to improve the heat exchange efficiency and prevent ash accumulation and scaling. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them:

[0041] Figure 1 The overall structure of the high-temperature flue gas rapid cooling waste heat boiler is schematically shown;

[0042] Figure 2 The cross-sectional structure of the boiler furnace is schematically shown;

[0043] Figure 3 The cross-sectional structure of the cluster casing is schematically shown;

[0044] Figure 4 The overall structure of the dry ice descaling device is schematically shown;

[0045] Figure 5 The overall structure of the converter primary flue gas pure dry purification treatment system is schematically shown;

[0046] Figure 6 The overall structure of the pure dry purification system for electric furnace flue gas is schematically shown.

[0047] Numbers in the figure:

[0048] 1-main smoke inlet pipe, 2-main smoke outlet pipe, 3-boiler body, 4-upper pipe header, 5-lower pipe header, 6-inlet section, 7-outlet section, 8-outer pipe, 9-inner pipe, 10-fixed distance rib plate, 11-spray pipe, 12-refractory masonry, 13-dry ice descaling device, 14-base, 15-guide rail frame, 16-driving device, 17-spray head, 18-dry ice descaling rod, 19-dry ice sending device, 20-nitrogen cleaning device, 21-soot blowing device;

[0049] 51-converter, 52-movable smoke hood and skirt, 53-evaporation cooling flue, 54-gas burner, 55-high-temperature phase-change heat storage device, 56-water-cooled three-way high-temperature reversing valve, 57-quenching waste heat boiler, 58-dust collector, 59-flue gas waste heat recovery device, 510-axial flow fan, 511-switching valve, 512-dispersion chimney, 513-gas cabinet, 514-first water-cooled two-way high-temperature reversing valve, 515-second water-cooled two-way high-temperature reversing valve;

[0050] 61-electric furnace, 62-mixed combustion settling tube, 57-quenching waste heat boiler, 64-dust collector, 65-continuous preheating device for scrap steel furnace gas, 66-chimney. DETAILED DESCRIPTION

[0051] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or restriction to the technical solution of the present invention.

[0052] Figure 1 The overall structure of a high-temperature flue gas rapid cooling waste heat boiler is schematically shown. Figure 1 As shown, it includes a main smoke inlet pipe 1 and a boiler furnace body 3 fixedly arranged between the main smoke inlet pipe 1 and the main smoke outlet pipe 2. The input end and the output end of the boiler furnace body 3 are respectively connected to the main smoke inlet pipe 1 and the main smoke outlet pipe 2. A plurality of descaling devices are also fixedly arranged on the main smoke outlet pipe 2. The aforementioned descaling devices and the boiler furnace body 3 are located on the same axis. The descaling devices coaxially arranged with the boiler furnace body 3 are used to clean the ash and scale attached to the inside of the boiler furnace body 3, thereby ensuring the fluidity of the high-temperature flue gas inside the waste heat boiler and enhancing the heat exchange efficiency.

[0053] Figure 2 The cross-sectional structure of the boiler body is schematically shown. Figure 2As shown, the aforementioned boiler furnace body 3 includes a cluster sleeve and an upper pipe header 4 and a lower pipe header 5 respectively fixedly arranged at both ends of the cluster sleeve. The upper pipe header 4 and the lower pipe header 5 are connected with the internal gap of the cluster sleeve to input heat exchange medium into the cluster sleeve to provide heat exchange for the high-temperature flue gas passing through the cluster sleeve, so that the high-temperature flue gas can complete a rapid cooling process. The high-temperature flue gas passes through an inlet section 6 and an outlet section 7 fixedly arranged at both ends of the cluster sleeve. The aforementioned inlet section 6 is connected with the main smoke inlet pipe 1, and the outlet section 7 is connected with the main smoke outlet pipe 2, that is, the high-temperature flue gas input from the main smoke inlet pipe 1 is divided through the inlet section 6 and enters multiple boiler furnace bodies 3 to complete a rapid cooling process, and then merges in the main smoke outlet pipe 2 and is discharged. By diverting the high-temperature flue gas and then using multiple boiler furnaces 3 to rapidly cool the diverted high-temperature flue gas, compared to directly rapidly cooling the high-temperature flue gas entering the main smoke inlet pipe 1, the diversion method can obviously complete the rapid cooling process faster, and the diversion method can greatly enhance the rapid cooling effect on the high-temperature flue gas. After that, the flue gas is discharged after merging in the main smoke outlet pipe 2 for subsequent dust removal process.

[0054] Figure 3 The cross-sectional structure of the cluster sleeve is schematically shown. Figure 2 as well as Figure 3The boiler furnace body 3 is described in detail. The clustered sleeves constituting the boiler furnace body 3 include an outer tube 8 and an inner tube 9, and a spacing rib plate 10 is fixedly arranged between the outer tube 8 and the inner tube 9. The spacing rib plate 10 limits the size of the gap between the outer tube 8 and the inner tube 9 on the one hand, and supports the inner wall of the outer tube 8 and the outer wall of the inner tube 9 on the other hand, and can divide the aforementioned gap into a plurality of separate cavities to facilitate the flow of heat exchange medium therethrough. Smaller cavities can effectively increase the flow velocity of the heat exchange medium, thereby increasing the heat exchange efficiency of the high-temperature medium flowing through the inner tube 9. The inlet section 6 and the outlet section 7 are connected and penetrated with the two ends of the inner tube 9 by a nozzle 11, and the nozzle 11 can be a Laval nozzle. A water inlet is provided on the lower manifold 5, and a drain outlet is provided on the upper manifold 4. The lower manifold 5 and the upper manifold 4 are fixedly arranged between the cluster sleeve and the water inlet / outlet based on the outer edge of the aforementioned nozzle 11, and are connected with the gap between the outer tube 8 and the inner tube 9, so that the heat exchange medium can enter the lower manifold 5 from the water inlet on the lower manifold 5, pass through the gap between the outer tube 8 and the inner tube 9, and then flow into the upper manifold 4 after completing the heat exchange process with the high-temperature flue gas flowing through the inner tube 9, and then be discharged through the drain outlet located on the upper manifold 4. In the heat exchange process, the high-temperature flue gas and the heat exchange medium are separated by the inner tube 9, and there is no contact between the two during the heat exchange process. Therefore, water vapor will not be contained in the high-temperature flue gas and mixed into the flue gas during the heat exchange process, thereby affecting the subsequent dust removal process, effectively avoiding the problem of "smoke plume", and at the same time, effectively recovering the waste heat from the high-temperature flue gas. It is worth noting that refractory brickwork 12 is fixedly installed in the aforementioned inlet section 6 and outlet section 7 .

[0055] Figure 4 The overall structure of the dry ice descaling device is shown schematically. Figure 4The dry ice descaling device 13 is described in detail. The dry ice descaling device 13 includes a base 14, a guide rail frame 15, a driving device 16 and an injection head 17. The guide rail frame 15 is fixedly arranged on the base 14, and the injection head 17 is fixedly arranged below the driving device 16, and is regulated by the driving device 16 to reciprocate along the length direction of the guide rail frame 15. The aforementioned dry ice descaling device 13 also includes a dry ice descaling rod 18. The aforementioned driving device 16 is fixedly arranged at one end of the dry ice descaling rod 18, and the injection head 17 is fixedly arranged at the other end of the dry ice descaling rod 18. The driving device 16 can drive the dry ice descaling rod 18 to rotate, and the injection head 17 fixed on the dry ice descaling rod 18 can rotate synchronously with the rotation of the dry ice descaling rod 18. The aforementioned driving device 16 can move in the length direction of the guide frame 15 fixed on the base 14, thereby driving the dry ice descaling rod 18 and the injection head 17 to move in the length direction of the guide frame 15 to complete the descaling process of the inner wall of the inner tube 9; however, in this process, because the injection head 17 is only facing a fixed direction, it can only descale one side of the inner wall of the inner tube 9, while it is difficult to achieve the descaling on the other side due to its orientation problem, so it is necessary to adjust the orientation of the injection head 17 to complete the descaling process of the inner wall of the inner tube 9, so the driving device 16 should also have a rotation process, and a servo motor and a transmission device can be provided thereon to synchronously control the rotation of the dry ice descaling rod 18 to complete the descaling of the inner wall of the inner tube 9.

[0056] The aforementioned injection head 17 uses a dry ice sending device 19 to transport dry ice thereto. A sending channel is opened in the aforementioned dry ice descaling rod 18 along its length direction. One end of the sending channel is connected to the output end of the dry ice sending device 19, and the other end is connected to the input end of the injection head 17. The dry ice sending device 19 uses the sending channel to eject block or spherical dry ice from the injection head 17 through the sending channel under the driving action of nitrogen, so that the block or spherical dry ice contacts the inner wall of the inner tube 9, so that the accumulated dust attached thereto is frozen and brittle, and is peeled off from the inner wall of the inner tube 9 under the action of dry ice. The cleaning efficiency is high and does not involve any chemical solvents and water, effectively avoiding dust accumulation and scaling.

[0057] In the process of directly sending dry ice to the aforementioned sending channel and ejecting it from the injection head 17, the dry ice as a solid will inevitably contact and rub against the inner wall of the launching channel, thereby causing the temperature in the launching channel to rise, accelerating the gasification process of the dry ice, and thus affecting the descaling process. A number of cooling water channels are also provided in the dry ice descaling rod 18. The cooling water channels can be provided based on the aforementioned launching channel, such as being arranged around the launching channel in a surrounding manner, and by injecting refrigerant therein and contacting with the launching channel, the launching channel is ensured to always be maintained within a certain temperature range, thereby ensuring the descaling effect on the inner wall of the inner tube 9. The water inlet and the drain of the aforementioned cooling water channel are fixedly provided on the driving device 16.

[0058] Because the inner tube 9 itself is a tube with a certain length, when the inner wall needs to be descaled, it is necessary to extend it into the inner tube to complete the descaling process. Therefore, the outer diameter of the dry ice descaling rod 18 needs to be smaller than the inner diameter of the inner tube 9 so that the dry ice descaling rod 18 can extend into it. In actual application, the driving device 16, the dry ice descaling rod 18 and the injection head 17 move synchronously, and only the driving device 16 contacts the guide rail frame 15. The movement direction of the dry ice descaling rod 18 and the injection head 17 is controlled by the guide rail frame 15, and the rotation process of the dry ice descaling rod 18 is regulated by the driving device 16. Since the injection head 17 and the dry ice descaling rod 18 are kept in a coaxial fixed state, the injection head 17 can rotate synchronously with the rotation of the dry ice descaling rod 18, thereby completing the descaling and cleaning process of the inner wall of the inner tube 9; the process of spraying dry ice onto the inner wall of the inner tube 9 is completely regulated by the aforementioned dry ice launch device.

[0059] The aforementioned boiler furnace bodies 3 and dry ice descaling devices 13 are both multiple, and the multiple boiler furnace bodies 3 and dry ice descaling devices 13 are fixedly arranged based on the length direction of the main smoke inlet pipe 1 and the main smoke outlet pipe 2.

[0060] The width of the main smoke inlet pipe 1 gradually decreases on the side away from the smoke inlet. Specifically, the further away from the smoke inlet, the lower surface gradually tilts upward, so that the further away from the smoke inlet, the smaller the width. When the high-temperature smoke enters the smoke inlet, the high-temperature smoke that enters the main smoke inlet pipe 1 first can be pushed into the boiler furnace body 3 inside by the high-temperature smoke that enters the main smoke inlet pipe 1 later. Because its internal space gradually decreases, the higher the speed of the high-temperature smoke that is farther away from the smoke inlet enters the boiler furnace body 3, and The speed of high-temperature flue gas entering the main smoke inlet pipe 1 from a position closer to the smoke inlet is relatively slow, and due to the squeezing of the subsequently input smoke, it rushes into each boiler furnace body 3, and there is no situation in which the smoke is retained in the main smoke inlet pipe 1; and a nitrogen cleaning device 20 is fixedly provided below the main smoke inlet pipe 1, which is used to clean the accumulated ash attached to the nozzle 11 close to the side of the main smoke inlet pipe 1, and an ash hopper is fixedly provided below the main smoke inlet pipe 1 close to the smoke inlet, which is used to collect the swept ash and discharge it in a centralized manner.

[0061] The width of the main smoke outlet pipe 2 on the side away from the smoke outlet gradually decreases, which is specifically manifested in that the further away from the smoke outlet, the lower surface gradually tilts upward, so that the further away from the smoke outlet, the smaller the width. When the smoke enters the main smoke outlet pipe 2, the closer to the main smoke outlet pipe 2, the slower the speed of the smoke, and the farther away from the main smoke outlet pipe 2, the faster the speed of the smoke. Due to the compression of the subsequent output smoke, the smoke rushes to the smoke outlet, thereby driving the smoke near the smoke outlet to complete the output, so that the speed of the smoke output from the smoke outlet is relatively balanced, and there will be no smoke retention. The upper surface of the main smoke outlet pipe 2 is in a horizontal state, and the aforementioned dry ice descaling device 13 is fixedly arranged on the upper surface of the main smoke outlet pipe 2 with a partition valve, and a soot blowing device 21 is also fixedly arranged on the upper surface of the main smoke outlet pipe 2 close to the partition valve, which is used to clean the accumulated dust attached to the nozzle 11 near the main smoke outlet 2. The ash blown off by the soot blowing device 21 and located in the nozzle 11 near the main smoke outlet pipe 2, the ash blown off from the inner wall of the inner tube 9 by the dry ice descaling device 13, and the ash blown off by the nitrogen cleaning device 20 and located in the nozzle 11 near the main smoke inlet pipe 1 will all fall into the aforementioned ash hopper or be stacked nearby, thereby being discharged from the ash hopper.

[0062] A method for recovering waste heat from high-temperature flue gas uses the aforementioned high-temperature flue gas rapid cooling waste heat boiler to complete waste heat recovery from high-temperature flue gas, specifically: after diverting the input high-temperature flue gas to multiple separate heat exchange carriers, low-temperature medium is input into the multiple heat exchange carriers to complete the heat exchange process with the high-temperature flue gas in the heat exchange carriers and then merged and discharged; during the process, the ash deposited on the boiler furnace body 3 is descaled according to different positions.

[0063] The following describes the application scenario of the aforementioned high-temperature flue gas rapid cooling waste heat boiler.

[0064] Example 1 (Application of high-temperature flue gas rapid cooling waste heat boiler to converter primary flue gas pure dry purification treatment system)

[0065] like Figure 5 As shown, the primary flue gas pure dry purification treatment system of the converter 51 includes a gas burner 54, a high-temperature phase-change heat storage device 55, a rapid cooling waste heat boiler 57 (i.e., the high-temperature flue gas rapid cooling waste heat boiler in the present invention), a dust collector 58 and a flue gas waste heat recovery device 59. The input end of the aforementioned flue gas waste heat recovery device 59 is connected to the output end of the dust collector 58, and the output end of the flue gas waste heat recovery device 59 is connected to the axial flow fan 510, and the output end of the axial flow fan 510 is connected to a switching valve 511, one end of the switching valve 511 is connected to the vent chimney 512, and the other end is connected to the gas tank 513.

[0066] It also includes a water-cooled three-way high-temperature reversing valve 56, the first channel of the input end of the water-cooled three-way high-temperature reversing valve 56 is connected to the gas burner 54, the second channel is connected to the input end of the high-temperature phase-change heat storage device, and the third channel is connected to the input end of the first water-cooled two-way high-temperature reversing valve 514. The first output end of the first water-cooled two-way high-temperature reversing valve 514 is connected to the input end of the dust collector 58, and the second output end is connected to the input end of the quenching waste heat boiler 57, and the output end of the quenching waste heat boiler 57 is also connected to the input end of the dust collector 58. The output end of the high-temperature phase-change heat storage device is connected to the input end of the quenching waste heat boiler 57 through the second water-cooled two-way high-temperature reversing valve 515.

[0067] It is worth noting that a pneumatic ash conveying and sending unit is provided below the high-temperature phase-change heat storage device, the rapid cooling waste heat boiler 57 (i.e., the high-temperature flue gas rapid cooling waste heat boiler in the present invention) and the dust collector 58, and is equipped with a fluidizing device to completely guide the accumulated ash in the high-temperature phase-change heat storage device, the rapid cooling waste heat boiler 57 and the dust collector 58 into the pneumatic ash conveying and sending unit. An emergency blowing device is also provided, and its output end is connected to the input end of the high-temperature phase-change heat storage device, the rapid cooling waste heat boiler 57 and the dust collector 58. The outputs of the aforementioned pneumatic ash conveying and sending unit, the fluidizing device and the emergency blowing device are all compressed nitrogen.

[0068] The high-temperature flue gas generated in the converter 51 is input into the input end of the water-cooled three-way high-temperature reversing valve 56 through the vaporization cooling flue 53 connected to the output end thereof. A movable smoke hood and a hood skirt 52 are provided between the vaporization cooling flue 53 and the converter 51 so that the high-temperature flue gas output from the converter 51 can flow completely to the vaporization cooling flue 53 without leaking out. A flue gas pressure transmitter, a flue gas temperature transmitter and a measuring device for measuring the contents of O2, CO and H2 in the flue gas are provided at the output end of the vaporization cooling flue 53. After measurement by the measuring device, the high-temperature flue gas is selectively input into one of the gas burner 54, the high-temperature phase change heat storage device 55 and the dust collector 58 by regulating the water-cooled three-way high-temperature reversing valve 56 to complete the purification process of the flue gas from the converter 51.

[0069] CO can be input into the gas burner 54 through the other input end of the aforementioned gas burner 54, and its output end is connected to the vaporization cooling flue 53. A water-cooled high-temperature resistant gate valve is provided between the output end of the gas burner 54 and the connection between the converter 51 and the movable smoke hood to regulate the input or output of high-temperature flue gas.

[0070] Example 2 (Applying a high-temperature flue gas rapid cooling waste heat boiler to an electric furnace flue gas pure dry purification treatment system)

[0071] like Figure 6 As shown, the pure dry purification treatment system of the flue gas from the electric furnace 61 includes the electric furnace 61, a mixed combustion settling cylinder 62, a rapid cooling type waste heat boiler 57 and a dust collector 64. A scrap steel furnace gas continuous preheating device 65 is also arranged on the aforementioned electric furnace 61. The high-temperature flue gas generated from the electric furnace 61 and the flue gas generated from the continuous preheating device 65 for scrap steel furnace gas are both input into the mixed combustion settling cylinder 62 from different input ports located on the mixed combustion settling cylinder 62 through their respective extraction pipes. The high-temperature flue gas output from the mixed combustion settling cylinder 62 enters the rapid cooling type waste heat boiler 57, undergoes diversion and rapid cooling, and then merges and is input into the dust collector 64 to complete dust removal treatment, and is finally discharged through the chimney 66.

[0072] The technical scope of the present invention is not limited to the contents in the above description. Those skilled in the art can make various deformations and modifications to the above embodiments without departing from the technical idea of ​​the present invention, and these deformations and modifications should all fall within the protection scope of the present invention.

Claims

1. A high-temperature flue gas rapid cooling waste heat boiler, characterized in that: The invention comprises a main smoke inlet pipe (1), a main smoke outlet pipe (2), and a boiler furnace body (3) fixedly arranged between the main smoke inlet pipe (1) and the main smoke outlet pipe (2); the input end and the output end of the boiler furnace body (3) are respectively connected to the main smoke inlet pipe (1) and the main smoke outlet pipe (2); a plurality of dry ice descaling devices (13) are also fixedly arranged on the main smoke outlet pipe (2); the dry ice descaling devices (13) and the boiler furnace body (3) are located on the same axis; The boiler furnace body (3) comprises a clustering sleeve and an upper pipe header (4) and a lower pipe header (5) respectively fixedly arranged at the two ends of the clustering sleeve, the upper pipe header (4) and the lower pipe header (5) are communicated with the internal gap of the clustering sleeve, and an inlet section (6) and an outlet section (7) respectively connected to the main smoke inlet pipe (1) and the main smoke outlet pipe (2) are fixedly arranged at the two ends of the clustering sleeve.

2. The high-temperature flue gas rapid cooling waste heat boiler according to claim 1, characterized in that: The clustering sleeve comprises an outer tube (8) and an inner tube (9), a spacing rib plate (10) is fixedly arranged between the outer tube (8) and the inner tube (9), the inlet section (6) and the outlet section (7) are connected and penetrated with the two ends of the inner tube (9) through a nozzle (11); a water inlet is provided on the lower tube header (5), and a water outlet is provided on the upper tube header (4); the lower tube header (5) and the upper tube header (4) are fixedly arranged between the clustering sleeve and the water inlet / outlet based on the outer edge surface of the nozzle (11), and penetrate the gap between the outer tube (8) and the inner tube (9).

3. The high-temperature flue gas rapid cooling waste heat boiler according to claim 2, characterized in that: Refractory brickwork (12) is fixedly arranged in the inlet section (6) and the outlet section (7).

4. The high-temperature flue gas rapid cooling type waste heat boiler according to claim 2, characterized in that: The dry ice descaling device (13) comprises a base (14), a guide rail frame (15), a driving device (16) and an injection head (17); the guide rail frame (15) is fixedly arranged on the base (14); the injection head (17) is fixedly arranged below the driving device (16) and is regulated by the driving device (16) to reciprocate along the length direction of the guide rail frame (15).

5. The high-temperature flue gas rapid cooling type waste heat boiler according to claim 4, characterized in that: It also includes a dry ice descaling rod (18), the driving device (16) is fixedly arranged at one end of the dry ice descaling rod (18), and the injection head (17) is fixedly arranged at the other end of the dry ice descaling rod (18), and the driving device (16) drives the dry ice descaling rod (18) to rotate the injection head (17).

6. The high-temperature flue gas rapid cooling type waste heat boiler according to claim 5, characterized in that: It also includes a dry ice sending device (19), wherein a sending channel is opened in the dry ice descaling rod (18) along its length direction, one end of the sending channel is connected to the output end of the dry ice sending device (19), and the other end is connected to the input end of the injection head (17).

7. The high-temperature flue gas rapid cooling type waste heat boiler according to claim 5, characterized in that: A plurality of cooling water channels are also provided in the dry ice descaling rod (18), and the water inlet and the water outlet of the cooling water channel are fixedly arranged on the driving device (16).

8. The high-temperature flue gas rapid cooling type waste heat boiler according to claim 5, characterized in that: The outer diameter of the dry ice descaling rod (18) is smaller than the inner diameter of the inner tube (9).

9. The high-temperature flue gas rapid cooling type waste heat boiler according to claim 1, characterized in that: The boiler furnace body (3) and the dry ice descaling device (13) are multiple, and the multiple boiler furnace bodies (3) and the dry ice descaling devices (13) are fixedly arranged based on the length direction of the main smoke inlet pipe (1) and the main smoke outlet pipe (2); The width of the main smoke inlet pipe (1) gradually decreases on the side away from the smoke inlet port, a nitrogen cleaning device (20) is fixedly arranged below the main smoke inlet pipe (1), and an ash hopper is fixedly arranged below the main smoke inlet pipe (1) close to the smoke inlet port; The width of the main smoke outlet pipe (2) gradually decreases on the side away from the smoke outlet, the dry ice descaling device (13) is fixedly arranged on the upper surface of the main smoke outlet pipe (2) by a partition valve, and a soot blowing device (21) is also fixedly arranged on the upper surface of the main smoke outlet pipe (2) close to the partition valve.

10. A method for recovering waste heat from high-temperature flue gas, characterized in that: The high-temperature flue gas rapid cooling waste heat boiler as described in any one of claims 1 to 9 is used to complete the waste heat recovery of the high-temperature flue gas, specifically: after the input high-temperature flue gas is diverted to multiple separate heat exchange carriers, a low-temperature medium is input into the multiple heat exchange carriers to complete the heat exchange process with the high-temperature flue gas in the heat exchange carriers, and then merged and discharged.

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