A process and device for comprehensive recovery and utilization of blast furnace slag waste heat

Abstract

The present invention discloses a comprehensive recovery and utilization process and device for waste heat from blast furnace slag, and relates to the technical field of waste heat recovery from blast furnace slag. The device specifically includes an inclined single-cylinder cooler, one side of the single-cylinder cooler is provided with a slag ditch and a hot air outlet, the other side of the single-cylinder cooler is provided with a conveying material box, and the interior of the heat recovery box is provided with two-stage step-type grate coolers, and the central axis of the single-cylinder cooler and the step-type grate cooler are not on the same horizontal line. The invention is to transform the mature and experienced equipment of the cement plant, and use the single-cylinder cooler and the grate cooler to rapidly cool the blast furnace slag to form a glass phase through the high-speed cooling air in the grate head of the grate cooler to continuously air-cool the grate plate to recover heat, so as to cool the blast furnace slag to about 100°C, and utilize the multi-stage high-temperature hot air obtained by heat exchange through a variety of existing equipment in the steel plant, which greatly improves the heat recovery efficiency and avoids the cost problems caused by major changes in the plant area.

Description

Technical Field

[0001] The present invention relates to the technical field of blast furnace slag waste heat recovery, and in particular to a process and device for comprehensive recovery and utilization of blast furnace slag waste heat. Background Art

[0002] Blast furnace slag is a by-product produced in the steel production process. It not only has important material resource recovery value, but also has important thermal energy resource recovery significance. According to calculations: At the national level: my country's crude steel output in 2023 is 1.019 billion tons (accounting for 53.97% of the world), and the corresponding molten blast furnace slag output exceeds 300 million tons. The temperature of molten blast furnace slag is often above 1400℃, and the calorific value is about 50kg standard coal / ton. The total amount of thermal energy resources contained in the blast furnace slag produced nationwide each year is as high as 4x1014 kJ. If all of it is recycled, it can generate a production value of tens of billions of yuan.

[0003] The current blast furnace slag water quenching technology used in actual industrial applications is to pour the molten blast furnace slag into water for rapid cooling, and granulate it under the action of thermal stress. Most of the slag particles (more than 95%) obtained after water quenching are amorphous, which is an excellent cement admixture. This method has achieved the bulk consumption of blast furnace slag. However, the water quenching method focuses on the recovery of material resources, and cannot simultaneously utilize the waste heat resources of blast furnace slag (only some northern steel companies can recover 10% of the heat for heating at the maximum), and the water quenching technology will lead to a large amount of water resource consumption and a high water content in the slag.

[0004] Patent CN202210340124.9: This invention uses a granulating drum with a coolant cooling coil to cool the high-temperature slag to 600°C on the rolling outer wall to form glassy slag. The glassy slag is squeezed and crushed in sequence by several groups of cooling granulating drums arranged in a vertical direction, and finally enters the heat exchanger for waste heat recovery. This invention takes into account the solidification, vitrification and crushing and granulation of the slag, but does not consider how to use the recovered waste heat in the steel plant and is not suitable for large-scale industrial production needs.

[0005] Patent CN201811170403.5: This invention uses a heat exchange unit composed of multiple heat exchange modules installed in the slag ditch in series to maximize the recovery of the sensible heat of the high-temperature liquid blast furnace slag flowing between the skimmer and the slag ditch head, obtain high-temperature and high-pressure steam, and achieve energy saving. This invention uses a soft water heat exchange module for heat exchange, and does not consider how to use the heat of high-temperature and high-pressure soft water.

[0006] Patent CN 202010079816.3: This invention uses a granulation bin with cooling circulating water as the wall surface to make the granulated liquid slag quickly cool and release heat on the wall surface of the granulation bin to solidify and recover the latent heat in the liquid blast furnace slag. Secondly, by adding a blower to the vibrating screening machine, solid-solid heat exchange in the moving bed heat exchanger, and adding circulating water on the conveyor belt, the sensible heat in the solid blast furnace slag is further recovered. This invention does not break away from the limitations of water-cooled heat recovery, and the wall heat exchange production efficiency is low.

[0007] Currently, most of these inventions are limited to water-cooled heat exchange on the wall where blast furnace slag is not in direct contact with water. The heat exchange efficiency is low and the recovered heat is difficult to use efficiently, which is not suitable for continuous production conditions in steel plants. Summary of the invention

[0008] The purpose of the present invention is to provide a comprehensive recovery and utilization process and device for waste heat from blast furnace slag to solve the above technical problems: The purpose of the present invention is to transform the mature and experienced equipment of the cement plant, and to cool the blast furnace slag to about 100°C by means of a single-drum cooler and a grate cooler, through which high-speed cooling air is used in the grate head to rapidly cool the blast furnace slag to form a glass phase, and the grate plate is continuously cooled by air to recover heat, and the multi-stage high-temperature hot air obtained by heat exchange is utilized through a variety of existing equipment in the steel plant, which greatly improves the heat recovery efficiency and avoids the cost problems caused by major changes in the plant area.

[0009] The purpose of the present invention can be achieved through the following technical solutions:

[0010] A device for comprehensive recovery and utilization of waste heat from blast furnace slag, comprising an inclined single-drum cooler, wherein a slag ditch and a hot air outlet one are arranged on one side of the single-drum cooler, a conveying box is arranged on the other side of the single-drum cooler, a heat recovery box is arranged below the conveying box, two-stage walking grate coolers are arranged inside the heat recovery box, the central axis of the single-drum cooler and the walking grate cooler are not on the same horizontal line, a roller crusher is arranged between the two-stage walking grate coolers, a first cooling zone, a second cooling zone and a third cooling zone are arranged in sequence below the two-stage walking grate coolers, cooling fans are arranged inside the first cooling zone, the second cooling zone and the third cooling zone, and the air supply volume of the cooling fans decreases in sequence; hot air outlet two, hot air outlet three, hot air outlet four and an exhaust gas outlet are arranged in sequence above the two-stage walking grate cooler.

[0011] As a further solution of the present invention: a retractable filter screen is arranged in the hot air outlet 1, the hot air outlet 2, the hot air outlet 3, the hot air outlet 4 and the exhaust gas outlet.

[0012] As a further solution of the present invention: the single-drum cooler includes an inner drum, one end of the inner drum is rotatably connected to a sealing disk, one side of the sealing disk is symmetrically provided with a feed port and a hot air outlet, the feed port is connected to the slag ditch, and the other end of the inner drum is rotatably connected to the conveying box.

[0013] As a further solution of the present invention: a circulating cooling air duct 1 and a circulating cooling air duct 2 are cross-arranged on the outside of the inner tube, the air inlet directions of the circulating cooling air duct 1 and the circulating cooling air duct 2 are opposite, an outer tube is arranged on the outside of the circulating cooling air duct 1 and the circulating cooling air duct 2, and the length of the outer tube is smaller than that of the inner tube.

[0014] As a further solution of the present invention: the inner wall surface of the inner cylinder is made of refractory bricks and is coated with high temperature resistant anti-sticking coating, and the outer cylinder is composed of a steel shell and thermal insulation cotton.

[0015] As a further solution of the present invention: a plurality of inclined material lifting plates are arranged in an array on the inner wall of the inner cylinder.

[0016] As a further solution of the present invention: two fixing blocks are symmetrically installed on both sides of the inner wall of the inner cylinder, and a material lifting plate is rotatably connected between the two fixing blocks, and the material lifting plate is an S-shaped structure.

[0017] As a further solution of the present invention: a transmission shaft is fixedly installed inside the inner cylinder, and a plurality of arc-shaped plates are installed at equal angles on the transmission shaft.

[0018] As a further solution of the present invention: a plurality of groups of inclined plates are cross-arranged inside the conveying box, a support block is fixedly installed below the inclined plate, a triangular pad is connected to the support block through a spring, and the triangular pad is in contact with the bottom of the inclined plate; a rotating motor is fixedly installed on one side of the conveying box, the output shaft of the rotating motor extends into the conveying box and is connected to a cam, and the cam is in contact with the bottom of the inclined plate.

[0019] A comprehensive recovery and utilization process of blast furnace slag waste heat, comprising the following steps:

[0020] Step 1: The blast furnace slag flows out of the blast furnace from the blast furnace tapping port and enters the single-drum cooler through the slag ditch, and is cooled and heat-exchanged by high-speed cooling air in the single-drum cooler to form solid glass phase slag or semi-molten state;

[0021] Step 2: After flowing out of the single-drum cooler, the slag is cooled again by high-speed cooling air at the grate head of the step-type grate cooler, and the remaining semi-molten slag is rapidly solidified to form solid glass-phase slag;

[0022] Step 3: The blast furnace slag particles then slide from the grate head to the grate plate and gradually cool down under the step-by-step conveying of the grate plate; then the particle size is controlled below 25 mm by a roller crusher and further cooled on subsequent grate plates, and finally the blast furnace slag temperature is cooled to within the range of ambient temperature + 65°C and discharged from the grate cooler for collection and storage;

[0023] Step 4: Recycle the heat through hot air outlet 1, hot air outlet 2, hot air outlet 3, hot air outlet 4 and the exhaust gas outlet.

[0024] Beneficial effects of the present invention:

[0025] 1. Realize the material resource recovery and waste heat resource recycling of blast furnace slag through air cooling.

[0026] 2. Through the single-drum cooler, grate cooler grate head and multiple fans with high-speed cooling air, the blast furnace slag is rapidly cooled and solidified to form a glass phase and granulate.

[0027] 3. The process fully quenches the liquid molten blast furnace slag to form a glass phase, so it can be used as cement raw material, roadbed material, etc.

[0028] 4. Through the step-by-step conveying technology of the grate cooler, the transportation of blast furnace slag and multi-stage waste heat recovery are realized.

[0029] 5. Carry out multi-stage hot air recovery based on the specific conditions of the steel plant to improve the efficiency of blast furnace slag waste heat recovery and reduce the cost of hot air waste heat utilization.

[0030] 6. Through the overall process layout of single-drum cooler-grate cooler-roller crusher, the continuous industrial production needs of dry granulation and waste heat recovery of blast furnace slag in steel plants can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings.

[0032] Figure 1 It is a front view structural schematic diagram of the recycling device of the present invention;

[0033] Figure 2 It is a schematic diagram of the overall structure of the single-drum cooler of the present invention;

[0034] Figure 3 It is a schematic diagram of the internal structure of the single-drum cooler of the present invention;

[0035] Figure 4 It is a schematic diagram of the internal structure of the conveying material box of the present invention;

[0036] Figure 5 This is a schematic diagram of the staggered arrangement of the first single-drum cooler and the grate cooler of the present invention;

[0037] Figure 6 It is a schematic diagram of the staggered arrangement of the second single-drum cooler and the grate cooler of the present invention;

[0038] Figure 7 It is a schematic diagram showing the change of the position of each row of grate plates of the grate cooler of the present invention over time.

[0039] In the figure: 1. single-drum cooler; 2. slag ditch; 3. conveying box; 4. heat recovery box; 11. inner drum; 12. outer drum; 13. gear ring; 14. sealing plate; 15. feed inlet; 16. hot air outlet 1; 17. circulating cooling air duct 1; 18. circulating cooling air duct 2; 19. fixing block; 110. lifting plate; 111. transmission shaft; 112. arc plate; 31. inclined plate; 32. rotating motor; 33. cam; 34. support block; 35. spring; 36. pad; 41. first cooling zone; 42. second cooling zone; 43. third cooling zone; 44. step-type grate cooler; 45. roller crusher; 46. hot air outlet 2; 47. hot air outlet 3; 48. hot air outlet 4; 49. exhaust gas outlet; 410. slag outlet; 411. filter screen. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Example 1

[0042] See also Figure 1 As shown, a device for comprehensive recovery and utilization of waste heat from blast furnace slag comprises a single-drum cooler 1 arranged obliquely, a slag ditch 2 and a hot air outlet 16 are arranged on one side of the single-drum cooler 1, a conveying material box 3 is arranged on the other side of the single-drum cooler 1, and a heat recovery box 4 is arranged below the conveying material box 3;

[0043] The heat recovery box 4 is provided with a two-stage step-by-step grate cooler 44 inside. To ensure that the slag is fully cooled, a step-by-step conveying technology is adopted, that is, the grate conveying units of each row move together in the slag conveying direction to convey the slag forward, and then the grate conveying units of each row move individually or alternately in the opposite direction of the slag conveying. At this time, due to the friction between the slag rows, the slag does not move synchronously when the single row of grate plates moves in the opposite direction, thereby realizing continuous conveying and cooling of the slag. The position of each row of the grate cooler changes with time as follows Figure 7 As shown (taking the 6-row grate plate grate cooler as an example), the central axis of the single-cylinder cooler 1 and the walking grate cooler 44 are not on the same horizontal line. Figure 5 and Figure 6 As shown; since the single-cylinder cooler 1 is constantly rotating, when the blast furnace slag inside it is lifted up and falls again, its position is offset relative to the central axis of the grate cooler, causing the slag to fall from the single-cylinder cooler 1 to one side on the grate bed of the grate cooler. Therefore, in order to evenly spread the blast furnace slag on the grate bed, the single-cylinder cooler 1 and the grate cooler are staggered so that their center lines are offset to a certain extent. At the same time, due to the inconsistent particle sizes generated during the solidification and granulation of blast furnace slag, the centrifugal force in the single-cylinder cooler 1 is different. When it falls on the grate bed, the uneven distribution of large and small particles affects the cooling effect. Therefore, according to the on-site working conditions, the single-cylinder cooler 1 and the center line of the grate cooler are set at a certain inclination angle to ensure that large and small particles are evenly distributed on the grate bed.

[0044] A roller crusher 45 is arranged between the two-stage step-type grate cooler 44. The roller crusher 45 is located at the tail of the first-stage grate cooler. The cooled blast furnace slag falls into the crushing area. The finer slag falls directly from the interval between the rollers to the second-stage grate cooler or the unloading device. The remaining slag is crushed by the extrusion and shearing action of the roller crushing cavity, so as to facilitate further cooling or recycling.

[0045] The first cooling zone 41, the second cooling zone 42 and the third cooling zone 43 are arranged in sequence below the two-stage step-type grate cooler 44, which are separated from each other by partitions. The first cooling zone 41, the second cooling zone 42 and the third cooling zone 43 are all provided with cooling fans, and the air supply of the cooling fans decreases successively, and the air supply per unit grate plate area is 5500Nm 3 / m 2 h decreases to 4000Nm 3 / m 2 h, then decrease to 2800Nm 3 / m 2 ·h; wind pressure decreases from 12kPa to 8kPa, and then to 4.5kPa.

[0046] The first stage has a large number of fans and a high air volume, which aims to provide a large amount of cooling air to rapidly cool the blast furnace slag and quickly solidify it to form a glass phase. The second and subsequent stages have a small number of fans and a low air volume, which aims to fully exchange heat with the solid blast furnace slag to obtain high-temperature hot air and reduce the blast furnace slag temperature to within the range of ambient temperature + 65°C.

[0047] A hot air outlet 2 46, a hot air outlet 3 47, a hot air outlet 48 and a waste gas outlet 49 are arranged in sequence above the two-stage walking grate cooler 44, which are separated from each other by partitions. The recovered heat can be used for the blast furnace body, the hot blast stove, the waste heat power plant, the heating equipment, etc., and a slag outlet 410 is arranged below it.

[0048] The hot air outlet 1 16 , the hot air outlet 2 46 , the hot air outlet 3 47 , the hot air outlet 48 and the exhaust gas outlet 49 are all provided with a retractable filter 411 , and the filter 411 can be driven to retract by a cylinder. Because dust also contains heat, when filtering is not needed, the filter 411 is not started for filtering, so as to maximize the use of heat. When filtering is needed, filtering can be carried out through the filter 411 .

[0049] Example 2

[0050] Based on Example 1, refer to Figure 2-3 As shown, the single-drum cooler 1 includes an inner drum 11, one end of the inner drum 11 is rotatably connected to a sealing disk 14, which plays a good sealing role to prevent heat loss, and one side of the sealing disk 14 is symmetrically provided with a feed port 15 and a hot air outlet 16, the feed port 15 is connected to the slag ditch 2, and the other end of the inner drum 11 is rotatably connected to the conveying box 3.

[0051] The inner tube 11 is cross-arranged with a circulating cooling air duct 17 and a circulating cooling air duct 2 18. The air inlet directions of the circulating cooling air duct 17 and the circulating cooling air duct 2 18 are opposite. The outer tube 12 is arranged outside the circulating cooling air duct 17 and the circulating cooling air duct 2 18. The outer tube 12 is rotatably connected with the inner tube 11. The length of the outer tube 12 is smaller than that of the inner tube 11, because it is necessary to install a gear ring 13 at both ends of the inner tube 11. By driving the gear ring 13 to rotate, the inner tube 11 is driven to rotate. The circulating cooling air ducts are connected to fans for cooling.

[0052] The purpose of setting the circulating cooling air duct is to make the inner tube 11 in a cooling environment, cooperate with the internal cooling air to accelerate the heat conversion; and the circulating cooling air duct generally has the highest conversion efficiency at the beginning. When it reaches the middle section, the temperature of the cold air has risen, and its conversion efficiency is very low. Therefore, the circulating cooling air duct 1 17 and the circulating cooling air duct 2 18 are cross-set to take in air from both ends in order to maximize the conversion efficiency.

[0053] The inner wall surface of the inner cylinder 11 is made of refractory bricks and coated with high-temperature resistant anti-stick coating to ensure that it is resistant to high temperature, wear and impact, corrosion, and has good thermal expansion stability; inside the single-cylinder cooler 1, due to the heat dissipation on the surface of the cylinder of the single-cylinder cooler 1, the molten blast furnace slag solidifies on the cylinder wall to form a kiln skin, and the kiln skin is exposed to the high-temperature molten slag during the rotation of the inner cylinder 11 and is melted to form slag particles or covered by the slag particles and solidified again, and this cycle is repeated to ensure that the molten blast furnace slag in the cooler flows in and the slag particles flow out, and the outer cylinder 12 is composed of a steel shell and thermal insulation cotton to keep it warm.

[0054] A plurality of inclined lifting plates 110 made of high temperature and wear resistant materials are arranged in an array on the inner wall of the inner cylinder 11. As the inner cylinder 11 rotates, the lifting plates 110 throw up the molten blast furnace slag, thereby facilitating heat exchange between the material and the cooling air.

[0055] Two fixed blocks 19 are symmetrically installed on both sides of the inner wall of the inner cylinder 11, and a lifting plate 110 is rotatably connected between the two fixed blocks 19. The lifting plate 110 is an S-shaped structure. By setting it into a rotating S-shaped structure, it can rotate automatically during the process of the inner cylinder 11 rotating and contacting the slag, which is beneficial to the throwing of materials and heat exchange with cooling air.

[0056] A transmission shaft 111 is fixedly installed inside the inner tube 11, and a plurality of arc plates 112 are installed at equal angles on the transmission shaft 111. When molten blast furnace slag enters, the flow force will drive the arc plates 112 to rotate, which is beneficial to the throwing of materials and heat exchange with cooling air.

[0057] Example 3

[0058] See also Figure 4 As shown, a plurality of groups of inclined plates 31 are cross-arranged inside the conveying material box 3, and the inclined plates 31 are rotatably connected to the inner wall of the conveying material box 3, and a support block 34 is fixedly installed below the inclined plate 31, and a triangular pad 36 is connected to the support block 34 through a spring 35, and the triangular pad 36 is in contact with the bottom of the inclined plate 31; a rotating motor 32 is fixedly installed on one side of the conveying material box 3, and the output shaft of the rotating motor 32 extends into the conveying material box 3 and is connected to the cam 33, and the cam 33 is in contact with the bottom of the inclined plate 31; the arrangement of the plurality of cross-groups of inclined plates 31 is to enable the semi-molten slag to be in contact with the cooling air in the conveying material box 3 for a longer time and completely become solid slag, which is convenient for subsequent operations; at the same time, the rotating motor 32 is started to drive the cam 33 to rotate, drive the inclined plate 31 to vibrate up and down, and vibrate the solid slag remaining on the inclined plate 31; at the same time, in order to protect the inclined plate 31, a triangular pad 36 and a spring 35 are provided to buffer it.

[0059] Example 4

[0060] Based on Example 1, please refer to Figure 1 As shown, the present invention is a comprehensive recovery and utilization process of blast furnace slag waste heat, comprising the following steps:

[0061] Step 1: The blast furnace slag flows out of the blast furnace from the blast furnace tapping port through the slag groove 2 and enters the single-drum cooler 1, where it is cooled and heat-exchanged by high-speed cooling air to form solid glass-phase slag or semi-molten state;

[0062] Step 2: After flowing out of the single-drum cooler 1, the slag is cooled again by high-speed cooling air at the grate head of the step-type grate cooler 44, and the remaining semi-molten slag is rapidly solidified to form solid glass-phase slag;

[0063] Step 3: The blast furnace slag particles then slide from the grate head to the grate plate and gradually cool down under the step-by-step conveying of the grate plate; then the particle size is controlled to be below 25 mm by the roller crusher 45 and further cooled on the subsequent grate plate, and finally the blast furnace slag temperature is cooled to within the range of ambient temperature + 65°C and discharged from the grate cooler for collection and storage;

[0064] Step 4: Recycle heat through the hot air outlet 1 16 , the hot air outlet 2 46 , the hot air outlet 3 47 , the hot air outlet 4 48 and the exhaust gas outlet 49 .

[0065] This solution: While cooling the slag, the cooling air temperature rises, but there is also a temperature gradient of the gas along the entire length of the cooling system. Therefore, according to the on-site process layout of the steel plant, the hot air also adopts a multi-stage collection strategy. High-temperature gas above 1200℃ can directly supply air to the blast furnace body, and the remaining high-temperature gas and medium-temperature gas can be heated to the specified temperature by the hot blast furnace to supply air to the blast furnace body or used for waste heat power generation. The low-temperature waste air at the end can be used for heating or discharged into the atmosphere as waste gas after purification. The purpose of this system is to fully recover the heat of blast furnace slag.

[0066] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A device for comprehensive recovery and utilization of blast furnace slag waste heat, characterized in that: The invention comprises a single-cylinder cooler (1) arranged obliquely, wherein a slag ditch (2) and a hot air outlet (16) are arranged on one side of the single-cylinder cooler (1), a conveying box (3) is arranged on the other side of the single-cylinder cooler (1), a heat recovery box (4) is arranged below the conveying box (3), and two sections of step-type grate coolers (44) are arranged inside the heat recovery box (4), the central axis of the single-cylinder cooler (1) and the step-type grate cooler (44) are not on the same horizontal line, and the two sections of the step-type grate cooler (44) are arranged between the central axis of the single-cylinder cooler (1) and the step-type grate cooler (44). A roller crusher (45) is provided; a first cooling zone (41), a second cooling zone (42) and a third cooling zone (43) are provided in sequence below the two-stage step-type grate cooler (44); cooling fans are provided inside the first cooling zone (41), the second cooling zone (42) and the third cooling zone (43); and the air supply volume of the cooling fans decreases in sequence; a second hot air outlet (46), a third hot air outlet (47), a fourth hot air outlet (48) and an exhaust gas outlet (49) are provided in sequence above the two-stage step-type grate cooler (44); The single-drum cooler (1) comprises an inner drum (11), one end of the inner drum (11) is rotatably connected to a sealing disk (14), one side of the sealing disk (14) is symmetrically provided with a feed port (15) and a hot air outlet (16), the feed port (15) is connected to a slag ditch (2), and the other end of the inner drum (11) is rotatably connected to a conveying box (3); A circulating cooling air duct 1 (17) and a circulating cooling air duct 2 (18) are cross-arranged on the outside of the inner cylinder (11); the air inlet directions of the circulating cooling air duct 1 (17) and the circulating cooling air duct 2 (18) are opposite; an outer cylinder (12) is arranged on the outside of the circulating cooling air duct 1 (17) and the circulating cooling air duct 2 (18); the length of the outer cylinder (12) is smaller than that of the inner cylinder (11); The inner wall surface of the inner cylinder (11) is made of refractory bricks and is coated with high temperature resistant anti-sticking paint, and the outer cylinder (12) is composed of a steel shell and thermal insulation cotton; Two fixing blocks (19) are symmetrically mounted on both sides of the inner wall of the inner cylinder (11), a material lifting plate (110) is rotatably connected between the two fixing blocks (19), and the material lifting plate (110) is an S-shaped structure; A transmission shaft (111) is also fixedly mounted inside the inner cylinder (11), and a plurality of arc-shaped plates (112) are mounted at equal angles on the transmission shaft (111).

2. A blast furnace slag waste heat comprehensive recovery and utilization device according to claim 1, characterized in that: A retractable filter screen (411) is disposed in each of the hot air outlet one (16), the hot air outlet two (46), the hot air outlet three (47), the hot air outlet four (48) and the exhaust gas outlet (49).

3. A blast furnace slag waste heat comprehensive recovery and utilization device according to claim 2, characterized in that: A plurality of inclined material lifting plates (110) are arranged in an array on the inner wall of the inner cylinder (11).

4. The device for comprehensive recovery and utilization of blast furnace slag waste heat according to claim 1, characterized in that: A plurality of groups of inclined plates (31) are cross-arranged inside the conveying material box (3), a support block (34) is fixedly mounted below the inclined plate (31), a triangular pad (36) is connected to the support block (34) via a spring (35), and the triangular pad (36) is in contact with the bottom of the inclined plate (31); a rotating motor (32) is fixedly mounted on one side of the conveying material box (3), an output shaft of the rotating motor (32) extends into the conveying material box (3) and is connected to a cam (33), and the cam (33) is in contact with the bottom of the inclined plate (31).

5. A comprehensive recovery and utilization process of blast furnace slag waste heat, characterized in that: The device for comprehensive recovery and utilization of waste heat from blast furnace slag as claimed in claim 1 comprises the following steps: Step 1: blast furnace slag flows out of the blast furnace from the blast furnace tapping port and enters the single-drum cooler (1) through the slag groove (2), and is cooled and heat-exchanged by high-speed cooling air in the single-drum cooler (1) to form solid glass-phase slag or semi-molten slag; Step 2: After flowing out of the single-drum cooler (1), the grate head of the step-type grate cooler (44) is cooled again by high-speed cooling air for heat exchange, and the remaining semi-molten slag is rapidly solidified to form solid glass-phase slag; Step 3: The blast furnace slag particles slide from the grate head to the grate plate and gradually cool down under the step-by-step conveyance of the grate plate; then the particle size is controlled to be less than 25 mm by the roller crusher (45) and further cooled on the subsequent grate plate, and finally the blast furnace slag temperature is cooled to within the range of ambient temperature + 65°C and discharged from the grate cooler for collection and storage; Step 4: Recycle the hot air through the hot air outlet 1 (16), the hot air outlet 2 (46), the hot air outlet 3 (47), the hot air outlet 4 (48) and the waste gas outlet (49).

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