Red mud waste heat recovery device

Abstract

The application provides a red residue waste heat recovery device, the application provides a red residue waste heat recovery device, by setting a heat recovery furnace, in the heat recovery furnace, from top to bottom, a first tube screen evaporator, a second tube screen evaporator, a third tube screen evaporator, a high-level tube screen coal economizer and a low-level tube screen coal economizer are sequentially arranged, the heat of the high-temperature slag generated in the magnesium reduction process is recovered through the cooperation of the devices, and the low-temperature slag is discharged, effectively overcoming the waste of energy caused by the natural cooling method of the slag generated in the existing magnesium production process. And the device of the application also generates steam for use in the factory while recovering the heat in the slag, so it also has the characteristics of reducing production cost.

Description

Technical Field

[0001] This application relates to the field of energy-saving technology, and in particular to a waste heat recovery device for red slag. Background Technology

[0002] Magnesium is one of the lightest of the commonly used metals and one of the most abundant elements in the Earth's crust, making up about 2.5% of its composition. It mainly exists as dolomite, calcium magnesium carbonate, and magnesite. Magnesium is primarily used in the manufacture of lightweight magnesium alloys and ductile iron, as well as in the production of automobiles, aircraft, scientific instruments, desulfurizers, dehydrogenators, fireworks, flash powder, magnesium salts, and Grignard reagents. It is also used to reduce and extract metallic beryllium, titanium, zirconium, hafnium, and uranium.

[0003] The Pidgeon process for magnesium smelting is a silicothermic process involving intermittent production in an externally heated reduction tank, and it has now become the primary method for magnesium smelting. The process involves calcining dolomite in a rotary kiln (calcination temperature 1150~1250℃), then grinding it into powder, mixing it with silicon-containing ferrosilicon powder and fluorite powder (containing 95% calcium fluoride), forming pellets, and feeding them into a heat-resistant steel reduction tank. In the reduction furnace, crude magnesium is produced by reduction at a temperature of 1190~1210℃ and a vacuum condition of 1.33~10 Pa. After refining, ingot casting, and surface treatment, metallic magnesium ingots are obtained.

[0004] In the production of magnesium metal, for every ton of magnesium metal produced, approximately 6.5 to 7 tons of magnesium metal smelting reduction slag are generated. This reduction slag, also known as furnace slag, contains a large amount of heat. The current practice is to cool it by natural cooling, but this method fails to recover the heat in the furnace slag, resulting in energy waste. Utility Model Content

[0005] This application provides a waste heat recovery device for red slag, which solves the problem of energy waste caused by the natural cooling of slag generated in the existing magnesium production process.

[0006] This application provides a waste heat recovery device for red slag, including a heat recovery furnace; The heat recovery furnace includes an upper feeding zone, a middle heat exchange zone, and a lower discharge hopper; The heat exchange zone of the heat recovery furnace is equipped with a first tube screen evaporator, a second tube screen evaporator, a third tube screen evaporator, an upper tube screen economizer, and a lower tube screen economizer, arranged sequentially from top to bottom. The inner wall of the heat exchange zone of the heat recovery furnace is also arranged as a membrane water-cooled wall by coiling heat exchange tubes. The top of the feeding zone of the heat recovery furnace is equipped with a feeding inlet, and a feeding grate is installed inside the feeding inlet.

[0007] Optionally, the input end of the lower-level tube screen economizer is connected to the demineralized water source via a feed water pump; The output end of the lower-level tube screen economizer is connected to the input end of the upper-level tube screen economizer. The output end of the upper-level tube screen economizer is connected to the deaerator head through a pipeline. The deaerator head is connected to the steam drum. The steam drum is also connected to the steam user.

[0008] Optionally, the steam drum is connected to the input terminals of the first tube screen evaporator, the second tube screen evaporator, and the third tube screen evaporator respectively via the first downcomer. The steam drum is connected to the inlet of the membrane water-cooled wall via a second downcomer; The output ends of the first tube-panel evaporator, the second tube-panel evaporator, the third tube-panel evaporator, and the membrane water-cooled wall are connected to the steam drum.

[0009] Optionally, the first tube screen evaporator, the second tube screen evaporator, the third tube screen evaporator, the upper tube screen economizer, and the lower tube screen economizer are all serpentine tubes coiled together, and the curved connecting parts, as well as the input and output ends, all pass through the side wall of the heat recovery furnace and are located outside the heat recovery furnace. The portions of the first tube-screen evaporator, second tube-screen evaporator, third tube-screen evaporator, upper tube-screen economizer, and lower tube-screen economizer located outside the heat recovery furnace are covered by insulation covers.

[0010] Optionally, the space between the insulation cover and the heat recovery furnace is filled with a filling layer; The filling layer is made of rock wool.

[0011] Optionally, the first tube-panel evaporator is inclined at an angle of 10-12° to the horizontal plane; Furthermore, the output end of the first tube evaporator is higher than the input end.

[0012] Optionally, a dust cover is provided at the feed inlet on the top of the heat recovery furnace; The dust cover is connected to the exhaust fan via a dust collector.

[0013] Optionally, the feeding zone of the heat recovery furnace is equipped with multiple feeders, which are triangular structures with their tips pointing upwards. The material feeder is set horizontally, and its two ends are connected to the two sides opposite to the feed area; Multiple fabric feeders are arranged in a triangular pattern on a vertical plane, with fewer feeders at the top and more at the bottom.

[0014] This application provides a waste heat recovery device for red slag. By setting up a heat recovery furnace, and within the furnace, sequentially arranged from top to bottom, a first tube-screen evaporator, a second tube-screen evaporator, a third tube-screen evaporator, an upper tube-screen economizer, and a lower tube-screen economizer, the heat generated in the high-temperature slag during the high-temperature magnesium reduction process is recovered, and the low-temperature slag is discharged. This effectively overcomes the drawback of existing magnesium production processes that rely on natural cooling of the slag, leading to energy waste. Furthermore, this application's device, while recovering heat from the slag through the aforementioned devices, also generates steam for plant use, thus reducing production costs. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a heat recovery furnace provided in one embodiment of this application; Figure 2 A schematic diagram of a waste heat recovery device for red slag provided in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of a heat recovery furnace provided in another embodiment of this application; Figure 4 A schematic diagram of a waste heat recovery device for red slag provided in another embodiment of this application; Figure 5 This is a schematic diagram of the structure of a heat recovery furnace provided in another embodiment of this application.

[0017] Explanation of reference numerals in the attached figures: 1. Heat recovery furnace; 2. Demineralized water source; 3. Deaerator; 4. Steam drum; 5. Steam user; 6. Insulation cover; 7. Dust collector; 10. Discharge hopper; 11. First tube screen evaporator; 12. Second tube screen evaporator; 13. Third tube screen evaporator; 14. Upper tube screen economizer; 15. Lower tube screen economizer; 16. Feed grate; 17. Dust cover; 20. Feed pump; 30. Exhaust fan; 41. First downcomer; 42. Second downcomer; 60. Packing layer; 101. Feed inlet; 115. Membrane water-cooled wall. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are also within the scope of protection of this application.

[0019] like Figure 1 As shown, this application provides a waste heat recovery device for red slag, including a heat recovery furnace 1; The heat recovery furnace 1 includes an upper feeding zone, a middle heat exchange zone, and a lower discharge hopper 10; The heat exchange zone of the heat recovery furnace 1 is provided with a first tube screen evaporator 11, a second tube screen evaporator 12, a third tube screen evaporator 13, an upper tube screen economizer 14, and a lower tube screen economizer 15 arranged sequentially from top to bottom. The inner wall of the heat exchange zone of the heat recovery furnace 1 is also arranged into a membrane water-cooled wall 115 by heat exchange tubes. The top of the feeding area of ​​the heat recovery furnace 1 is provided with a feed inlet 101, and a feed grate 16 is provided inside the feed inlet 101.

[0020] After magnesium reduction slag cools naturally in air, the surface layer gradually pulverizes into fine powder, while the center remains lumpy. This is mainly because the reduction efficiency on the outer surface of the lumps in the Pidgeon process is very high, reaching over 90%, with β-2CaOSiO2 as its main component, while the reduction efficiency of magnesium inside the lumps is typically less than 85%. Any residue with a reduction efficiency of 85% (i.e., β-2CaOSiO2) transforms into γ-2CaOSiO2 when the temperature drops from 1200℃ to 675℃, at which point the 10% volume expansion residue completely pulverizes. Therefore, in the scheme of this application, as the red slag descends and its temperature decreases, it gradually becomes powdery, thus preventing slag from clogging the gaps between the tubes.

[0021] In the slag cooling process, the slag produced during magnesium reduction (causing high furnace exit temperature and a red-hot state, hence also called red slag) is poured into the heat recovery furnace 1 from the feed inlet 101 at the top of the furnace. It falls into the first tube-panel evaporator 11, where it exchanges heat with the tubes, heating and vaporizing the hot water. Since the first tube-panel evaporator 11 has the highest slag temperature, it is tilted to increase the heat exchange area, thereby enhancing its heat absorption capacity for the red slag and reducing the temperature of the bottom slag discharge. Similarly, after heat exchange in the first tube-panel evaporator 11, the red slag passes sequentially from top to bottom through the membrane water-cooled wall 115, the second tube-panel evaporator 12, the third tube-panel evaporator 13, the upper tube-panel economizer 14, and the lower tube-panel economizer 15, exchanging heat with the demineralized water. The demineralized water absorbs the heat from the red slag to generate steam, thus recovering the heat from the red slag.

[0022] It should also be noted that a spiral discharger is installed at the bottom of the discharge hopper 10. This seals off the heat recovery furnace 1, preventing dust generated during the slag's descent from escaping and causing environmental pollution. Furthermore, the spiral discharger ensures that the slag is gradually discharged along with the material, extending the slag's residence time within the heat recovery furnace 1 and thus improving heat exchange efficiency. In actual use, the slag fills the heat exchange zone and the discharge hopper, creating a combined heat exchange system where the evaporators and economizers inside the heat recovery furnace 1 exchange heat with the slag, and the membrane water-cooled walls 115 on the inner side of the heat exchange zone of the heat recovery furnace 1 also exchange heat with the slag. This enhances the heat exchange effect and reduces the slag discharge temperature. In actual operation, the spacing between adjacent pipes in the first tube-screen evaporator 11 is 150±10mm, the spacing between adjacent pipes in the second tube-screen evaporator 12 is 120±10mm, and the spacing between adjacent pipes in the third tube-screen evaporator 13 is 110±5mm. This arrangement of sparse upper and dense lower sections allows the high-temperature slag to fall quickly, preventing the first tube-screen evaporator 11 from overheating and the evaporator below it from having insufficient heat exchange.

[0023] This application provides a waste heat recovery device for red slag. By setting up a heat recovery furnace 1, and within the furnace 1, sequentially arranged from top to bottom, a first tube-screen evaporator 11, a second tube-screen evaporator 12, a third tube-screen evaporator 13, an upper tube-screen economizer 14, and a lower tube-screen economizer 15, the heat generated in the high-temperature slag during the magnesium reduction process is recovered, and the low-temperature slag is discharged. This effectively overcomes the drawback of energy waste caused by the natural cooling method used in existing magnesium production processes. Furthermore, this device, while recovering heat from the slag, also generates steam for plant use, thus reducing production costs.

[0024] like Figure 2As shown, optionally, the input end of the lower-level pipe screen economizer 15 is connected to the demineralized water source 2 via the feed water pump 20; The output end of the lower-level tube screen economizer 15 is connected to the input end of the upper-level tube screen economizer 14. The output end of the upper-level tube screen economizer 14 is connected to the deaerator head 3 through a pipeline. The deaerator head 3 is connected to the steam drum 4. Steam drum 4 is also connected to steam user 5.

[0025] During the heating process of the heat exchange medium (i.e., demineralized water), the demineralized water is supplied to the lower-level tube screen economizer 15 to exchange heat with the slag, and then enters the upper-level tube screen economizer 14 to exchange heat with the slag again. After heat exchange, the demineralized water enters the deaerator 3 connected to the steam drum 4 for deoxygenation, and then enters the steam drum to exchange heat with the steam-water mixture returned from the evaporator to raise its temperature.

[0026] Since the water entering the above-mentioned evaporators and membrane water-cooled walls 115 has been heated by the previous process, this water will vaporize and generate steam when it comes into contact with the high-temperature slag for heat exchange, forming a steam-water mixture. This steam-water mixture then enters the steam drum through the corresponding return water pipe for steam-water separation. At the same time, it can also heat the hot water supplied by the upstream economizer 14. The steam after steam-water separation is output from the steam drum 4 and supplied to steam users 5 (such as generators, steam heating equipment, etc.).

[0027] like Figure 2 As shown, optionally, the steam drum 4 is connected to the input end of the first tube screen evaporator 11, the input end of the second tube screen evaporator 12 and the input end of the third tube screen evaporator 13 respectively through the first downcomer 41. The steam drum 4 is connected to the input end of the membrane water-cooled wall 115 via the second downcomer 42; The output ends of the first tube-panel evaporator 11, the second tube-panel evaporator 12, the third tube-panel evaporator 13, and the membrane water-cooled wall 115 are connected to the steam drum 4.

[0028] Part of the heated hot water is distributed from the first downcomer 41 to the first tube-screen evaporator 11, the second tube-screen evaporator 12, and the third tube-screen evaporator 13 to exchange heat with the high-temperature slag; the other part enters the membrane water-cooled wall 115 from the second downcomer 42. In actual use, the slag fills the heat exchange zone and the discharge hopper, thus forming a comprehensive heat exchange method where the evaporators and economizers inside the heat recovery furnace 1 exchange heat with the slag, and the membrane water-cooled wall 115 on the inner side of the heat exchange zone of the heat recovery furnace 1 exchanges heat with the slag, thereby improving the heat exchange effect and reducing the slag discharge temperature. In actual operation, the spacing between adjacent pipes in the first tube-screen evaporator 11 is 150±10mm, the spacing between adjacent pipes in the second tube-screen evaporator 12 is 120±10mm, and the spacing between adjacent pipes in the third tube-screen evaporator 13 is 110±5mm. This arrangement of sparse upper and dense lower sections allows the high-temperature slag to fall quickly, preventing the first tube-screen evaporator 11 from overheating and the evaporator below it from having insufficient heat exchange.

[0029] like Figure 3 As shown, optionally, the first tube screen evaporator 11, the second tube screen evaporator 12, the third tube screen evaporator 13, the upper tube screen economizer 14 and the lower tube screen economizer 15 are all serpentine pipes, and the curved connection parts, as well as the input end and the output end, all pass through the side wall of the heat recovery furnace 1 and are located outside the heat recovery furnace 1. The portions of the first tube-screen evaporator 11, the second tube-screen evaporator 12, the third tube-screen evaporator 13, the upper tube-screen economizer 14, and the lower tube-screen economizer 15 located outside the heat recovery furnace 1 are covered by an insulation cover 6.

[0030] In this application, since the aforementioned tube-panel evaporator and economizer are under high-temperature conditions in the heat recovery furnace 1 and the demineralized water inside is heated to generate high pressure, the pipes located in the heat recovery furnace 1 must be seamless, i.e., integrally formed. Otherwise, the pipes are prone to rupture due to high temperature and high pressure conditions, making them difficult to repair. In this application, the aforementioned devices are all serpentine. Under existing technical conditions, the U-shaped bends are mostly connected by welding. However, the welded joints are prone to damage due to the aforementioned high temperature and high pressure conditions, leading to leakage. Therefore, these U-shaped bends are located outside the furnace to avoid damage and leakage that could cause danger inside the furnace. Also, being located outside the furnace facilitates inspection and maintenance. However, the aforementioned equipment being exposed outside the furnace will cause heat loss, which will not only lead to heat waste but also increase the temperature of the working environment, affecting production. Therefore, the pipes exposed outside the furnace are covered with insulation covers 6 to avoid the aforementioned heat waste and adverse consequences affecting the working environment.

[0031] In this application, since the output end of the lower-level tube screen economizer 15 is connected to the input end of the upper-level tube screen economizer 14, the connecting pipe at this location is located outside the insulation cover 6 because it needs to be frequently inspected. The pipe here is covered with a separate insulation layer to keep the pipe warm.

[0032] like Figure 3 As shown, optionally, the space between the insulation cover 6 and the heat recovery furnace 1 is filled by a filling layer 60; The filling layer 60 is made of rock wool.

[0033] In this application, since the inside of the pipe is in a high-temperature state, conventional organic insulation materials such as foamed resin are difficult to withstand such high temperatures, while rock wool is an inorganic insulation material that can withstand high temperatures of thousands of degrees Celsius. Therefore, rock wool is set as a filling layer to fill the space inside the insulation cover 6 to achieve the insulation effect.

[0034] Optionally, the first tube-panel evaporator 11 is inclined at an angle of 10~12° to the horizontal plane; Furthermore, the output of the first tube-panel evaporator 11 is higher than its input.

[0035] In this application, since the first tube screen evaporator 11 comes into contact with the slag at the highest temperature, it is set in an inclined state to increase the heat exchange area, thereby improving the heat absorption capacity of the first tube screen evaporator 11 for the red slag, while reducing the temperature of the bottom slag discharge.

[0036] like Figure 4 As shown, optionally, a dust cover 17 is provided at the feed inlet 101 at the top of the heat recovery furnace 1; The dust cover 17 is connected to the exhaust fan 30 via the dust collector 7.

[0037] In this application, dust is generated during the dumping of red slag. Therefore, the dust cover 17 is installed to reduce dust dispersion. At the same time, the negative pressure created by the exhaust fan 30 can reduce dust escape. During operation, the slag generated during the magnesium reduction process (which causes high furnace temperature and is red-hot, hence the name red slag) is dumped into the heat recovery furnace 1 from the feed port 101 at the top of the heat recovery furnace 1. At the same time, the exhaust fan 30 is turned on to suck in the dust generated during the dumping of red slag through the dust cover 17, and the dust is removed by the dust collector 7 to reduce the pollution of the environment by the dust agitated during slag dumping.

[0038] like Figure 5 As shown, optionally, multiple feeders 18 are provided in the feeding zone of the heat recovery furnace 1. The feeders 18 are triangular structures with their tips pointing upwards. The feeder 18 is set horizontally, and its two ends are connected to the two sides opposite to the feed area; Multiple fabric feeders 18 are arranged in a triangular pattern on a vertical plane, with fewer at the top and more at the bottom.

[0039] In this application, during use, the slag is sorted and intercepted by the feed grate 16. Small slag particles that can pass through the gaps in the feed grate 16 fall down, while large slag particles on the grate can be cleaned by manual crushing or scraping to prevent large slag pieces from clogging the feed grate 16. The slag is evenly distributed by the multiple distributors 18 set in the feeding zone and the buffering effect. After being distributed by the distributors 18 in the feeding zone, the red slag falls to the first tube screen evaporator 11 and exchanges heat with the tube screen in the tube screen evaporator 11.

[0040] A waste heat recovery device for red slag, the working process of which is as follows: During the cooling process of the slag, the slag produced during the magnesium reduction process (which causes the furnace to open at a high temperature and is in a red-hot state, hence the name red slag) is poured into the heat recovery furnace 1 from the feed port 101 at the top of the heat recovery furnace 1. At the same time, the exhaust fan 30 is turned on to suck up the dust generated during the pouring of the red slag through the dust cover 17, and the dust is removed by the dust collector 7 to reduce the pollution of the environment caused by the dust stirred up during the pouring of the slag.

[0041] The slag is sorted and intercepted by the feed grate 16. Small slag particles that can pass through the gaps in the feed grate 16 fall down, while large slag particles on the grate can be cleaned by manual crushing or scraping to prevent large pieces of slag from clogging the feed grate 16. The slag is evenly distributed by the multiple distributors 18 set in the feeding zone and the buffering effect. After being distributed by the distributors 18 in the feeding zone, the red slag falls to the first tube screen evaporator 11, where it exchanges heat with the tube screen in the tube screen evaporator 11, heating and vaporizing the hot water there. Since the first tube screen evaporator 11 has the highest slag temperature in contact with it, it is set in an inclined state to increase the heat exchange area, thereby improving the heat absorption capacity of the first tube screen evaporator 11 for the red slag, while reducing the temperature of the bottom slag discharge. Similarly, after the red slag exchanges heat with the first tube screen evaporator 11, it passes through the membrane water-cooled wall 115, the second tube screen evaporator 12, the third tube screen evaporator 13, the upper tube screen economizer 14, and the lower tube screen economizer 15 from top to bottom, and exchanges heat with the demineralized water therein. The demineralized water absorbs the heat from the red slag to generate steam, thus realizing the reuse of the heat from the red slag.

[0042] It should also be noted that a spiral discharger is installed at the bottom of the discharge hopper 10. This seals off the heat recovery furnace 1, preventing dust generated during the slag's descent from escaping and causing environmental pollution. Furthermore, the spiral discharger ensures that the slag is gradually discharged along with the material, extending the slag's residence time within the heat recovery furnace 1 and thus improving heat exchange efficiency. In actual use, the slag fills the heat exchange zone and the discharge hopper, creating a combined heat exchange system where the evaporators and economizers inside the heat recovery furnace 1 exchange heat with the slag, and the membrane water-cooled walls 115 on the inner side of the heat exchange zone of the heat recovery furnace 1 also exchange heat with the slag. This enhances the heat exchange effect and reduces the slag discharge temperature. In actual operation, the spacing between adjacent pipes in the first tube-screen evaporator 11 is 150±10mm, the spacing between adjacent pipes in the second tube-screen evaporator 12 is 120±10mm, and the spacing between adjacent pipes in the third tube-screen evaporator 13 is 110±5mm. This arrangement of sparse upper and dense lower sections allows the high-temperature slag to fall quickly, preventing the first tube-screen evaporator 11 from overheating and the evaporator below it from having insufficient heat exchange.

[0043] During the heating process of the heat exchange medium (i.e., demineralized water), the feed water pump 20 supplies demineralized water from the demineralized water source 2 to the lower-level tube screen economizer 15 to exchange heat with the slag, and then enters the upper-level tube screen economizer 14 to exchange heat with the slag again. After heat exchange, the demineralized water enters the deaerator 3 connected to the steam drum 4 to be deoxygenated, and then enters the steam drum to exchange heat with the steam-water mixture returned from the evaporator to raise its temperature. Part of the heated hot water is distributed from the first downcomer 41 to the first tube screen evaporator 11, the second tube screen evaporator 12 and the third tube screen evaporator 13 to exchange heat with the high-temperature slag; the other part enters the membrane water-cooled wall 115 from the second downcomer 42.

[0044] Since the water entering the above-mentioned evaporators and membrane water-cooled walls 115 has been heated by the previous process, this water will vaporize and generate steam when it comes into contact with the high-temperature slag for heat exchange, forming a steam-water mixture. This steam-water mixture then enters the steam drum through the corresponding return water pipe for steam-water separation. At the same time, it can also heat the hot water supplied by the upstream economizer 14. The steam after steam-water separation is output from the steam drum 4 and supplied to steam users 5 (such as generators, steam heating equipment, etc.).

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A red slag waste heat recovery device, characterized by, Including heat recovery furnace (1); The heat recovery furnace (1) includes an upper feeding zone, a middle heat exchange zone and a lower discharge hopper (10). The heat exchange zone of the heat recovery furnace (1) is provided with a first tube screen evaporator (11), a second tube screen evaporator (12), a third tube screen evaporator (13), an upper tube screen economizer (14), and a lower tube screen economizer (15) arranged from top to bottom. The inner wall of the heat exchange zone of the heat recovery furnace (1) is also arranged as a membrane water-cooled wall (115) by heat exchange tubes. The heat recovery furnace (1) has a feed inlet (101) at the top of the feeding area, and a feed grate (16) is provided inside the feed inlet (101).

2. The red slag heat recovery device according to claim 1, characterized by The input end of the lower-level tube screen economizer (15) is connected to the demineralized water source (2) through the water supply pump (20); The output end of the lower-level tube screen economizer (15) is connected to the input end of the upper-level tube screen economizer (14). The output end of the upper-level tube screen economizer (14) is connected to the deaerator head (3) through a pipeline. The deaerator head (3) is connected to the steam drum (4). The steam drum (4) is also connected to the steam user (5).

3. The red slag heat recovery device according to claim 2, characterized by The steam drum (4) is connected to the input end of the first tube screen evaporator (11), the input end of the second tube screen evaporator (12) and the input end of the third tube screen evaporator (13) respectively through the first downcomer (41); The steam drum (4) is connected to the input end of the membrane water-cooled wall (115) through the second downcomer (42); The output ends of the first tube-screen evaporator (11), the second tube-screen evaporator (12), the third tube-screen evaporator (13), and the membrane water-cooled wall (115) are connected to the steam drum (4).

4. The red slag heat recovery device according to claim 1, characterized by The first tube screen evaporator (11), the second tube screen evaporator (12), the third tube screen evaporator (13), the upper tube screen economizer (14) and the lower tube screen economizer (15) are all serpentine pipes coiled together, and the curved connection part, as well as the input end and the output end, all pass through the side wall of the heat recovery furnace (1) and are located outside the heat recovery furnace (1). The portions of the first tube screen evaporator (11), the second tube screen evaporator (12), the third tube screen evaporator (13), the upper tube screen economizer (14), and the lower tube screen economizer (15) located outside the heat recovery furnace (1) are covered by a heat insulation cover (6).

5. The red slag heat recovery device according to claim 4, wherein The heat insulation cover (6) and the heat recovery furnace (1) are filled by a filling layer (60); The filling layer (60) is made of rock wool.

6. The red slag heat recovery device according to claim 1, wherein The first tube-screen evaporator (11) is inclined at an angle of 10~12° to the horizontal plane; Furthermore, the output end of the first tube-screen evaporator (11) is higher than the input end.

7. The red slag heat recovery device according to claim 1, wherein A dust cover (17) is provided at the feed inlet (101) at the top of the heat recovery furnace (1); The dust cover (17) is connected to the exhaust fan (30) via a dust collector (7).

8. The red slag heat recovery device according to any one of claims 1 to 7, characterized in that, The heat recovery furnace (1) is equipped with multiple feeders (18) in the feeding area. The feeders (18) are triangular structures with the pointed ends facing upwards. The feeder (18) is set horizontally and its two ends are connected to the two sides opposite to the feed area; The plurality of distributors (18) are arranged in a triangular pattern with more distributors at the top than at the bottom in the vertical plane.

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