Sectional type steel slag waste heat recovery system and method

Abstract

The invention relates to the technical field of waste heat recovery, and discloses a sectional type steel slag waste heat recovery system and method.The sectional type steel slag waste heat recovery system comprises a steel slag crushing hot gas heat exchange suite arranged on a crushing vehicle and surrounding crushing rollers, and the steel slag crushing hot gas heat exchange suite is composed of a surrounding cover and a gathering cover which are distributed up and down; the inner wall of the surrounding cover and the inner wall of the gathering cover are fixedly connected with partition rib plates which are symmetrically distributed along the axis of the crushing roller at equal intervals, and the interior of the steel slag crushing hot gas heat exchange kit is divided into a plurality of gas gathering grooves corresponding to the crushing roller heads through the partition rib plates; the top-mounted high-temperature heat exchange is realized by utilizing a hot air rising effect generated after the steel slag is crushed and raised, the temperature of the high-temperature steel slag is effectively utilized, meanwhile, the steel slag is not in contact with each other, and the heat exchange efficiency is improved and the structure is simplified by utilizing high-temperature air generated inside the raised steel slag pile to quickly exchange heat at the first time. And an improvement can be additionally arranged on an existing crushing vehicle, and the influence caused by contact with high-temperature steel slag does not need to be overcome.

Description

Technical Field

[0001] This invention relates to the field of waste heat recovery technology, specifically a segmented steel slag waste heat recovery system and method. Background Technology

[0002] Traditional cooling processes for molten steel slag mainly include hot quenching, drum cooling, air quenching, and hot pouring. Among these, the hot pouring method has been gradually phased out due to the generation of large amounts of dust and harmful gases. The remaining processes generally employ water spraying or forced ventilation for cooling, resulting in high water consumption, high energy consumption, and severe pollution. Taking the hot quenching method as an example, after the high-temperature steel slag is poured into a quenching pool or slag pot, it is rapidly cooled and solidified by spraying water. During this process, the liquid water vaporizes instantly upon contact with the high-temperature steel slag, leading to a serious waste of water resources. More importantly, the high-quality residual heat carried by the steel slag is not effectively recovered and is completely dissipated into the environment.

[0003] Currently, waste heat recovery technologies and equipment for steel slag are still relatively limited, mainly including hot quenching waste heat recovery processes, grate-cooling waste heat recovery processes, and vertical waste heat recovery processes. The hot quenching waste heat recovery process places high-temperature metallurgical slag in a pressure vessel and directly injects water to generate steam. This method consumes a large amount of water, generates a large amount of wastewater, and the generated steam carries a large amount of impurities, making it difficult to utilize directly. The grate-cooling waste heat recovery process places high-temperature metallurgical slag in a dedicated grate cooler, and a blower introduces cold air from the bottom. The heated air is discharged from the top and transported to a waste heat boiler for steam production. However, this process suffers from high air leakage, low heat exchange efficiency, and high dust content in the flue gas.

[0004] The Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, has applied for a patent entitled "A High-Temperature Steel Slag Roller Crushing and Waste Heat Recovery System" (patent publication number CN117778642A). This patent incorporates rake-shaped heat exchange teeth into the roller crushing process, utilizing these teeth to directly contact and exchange heat with high-temperature steel slag exceeding 1000 degrees Celsius, thus achieving high-temperature waste heat utilization. However, because the rake-shaped heat exchange teeth need to contact the high-temperature steel slag, a solid structure is necessary for stability. The contact surface of the rake-shaped heat exchange teeth is the side, and since they are embedded on the circumference of the pipe, the actual heat exchange area between the rake-shaped heat exchange teeth and the liquid inside the pipe is only at the contact surface between the rake-shaped heat exchange teeth and the pipe. Therefore, the heat exchange area is too small, resulting in low heat exchange efficiency. Furthermore, the pipe, which serves as the connector for the rake-shaped heat exchange teeth, has a hollow structure. The relative force generated by the steel slag exerts on the pipe, and while increasing the pipe wall thickness increases its strength, the heat exchange efficiency remains low. If the pipe wall is thin, the conduction speed is fast, but if it is exposed to steel slag and high temperature for a long time, the pipe is prone to bending and deformation, which makes the actual application effect of this method poor. Summary of the Invention

[0005] The purpose of this invention is to provide a segmented steel slag waste heat recovery system and method, which integrates steel slag cooling, crushing, grading and waste heat recovery functions. In the process of roller crushing, the hot air generated by crushing is used for heat exchange, so that the whole device does not need to overcome the influence caused by contact with high temperature steel slag, and ensures the stable operation of the steel slag crushing hot air heat exchange kit, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A segmented steel slag waste heat recovery system includes a steel slag crushing hot air heat exchange kit installed on a crushing vehicle and surrounding the crushing rollers. The hot air heat exchange kit consists of an upper and lower surrounding cover and a gathering cover. The inner walls of the surrounding cover and the gathering cover are fixedly connected with symmetrically distributed partition ribs along the axis of the crushing rollers. The interior of the steel slag crushing hot air heat exchange kit is divided into multiple air-gathering grooves corresponding to the crushing roller heads by the partition ribs. A hot air heat exchange tube is coiled inside the steel slag crushing hot air heat exchange kit. The demineralized water delivery end of the hot air heat exchange tube is connected to a liquid supply system. The demineralized water delivery end enters from the bottom of the surrounding cover. The hot air heat exchange tube circulates along the periphery of the surrounding cover and the partition ribs, then bends upwards and repeats the coiling. The partition ribs have a periphery after coiling. Finally, the demineralized water return end of the hot air heat exchange tube extends out from the side and top of the gathering cover and is sequentially connected to a water tank, a steam generator, and a steam pipeline network.

[0008] As a further embodiment of the present invention: the top of the gathering cover is provided with an exhaust fan and / or the inner wall of the gathering cover is provided with a spray water pipe.

[0009] As a further embodiment of the present invention: the slag material crushed by the crushing roller enters the interior of the drum heat exchanger, the drum heat exchanger is equipped with pipelines and realizes liquid delivery, liquid cooling and circulation through water inlet and water outlet and circulating cooling equipment, one end of the drum heat exchanger is provided with a slag discharge port, and a slag tank is provided below the slag discharge port.

[0010] As a further embodiment of the present invention: the outer cover of the drum heat exchanger is provided with a waste heat exchange cover, the waste heat exchange cover is composed of a cover body and a spiral heat exchange tube, the spiral heat exchange tube is tightly attached to the outer wall of the drum, the steam generator is provided with a downcomer, the downcomer is connected to the spiral heat exchange tube, and the other end of the spiral heat exchange tube is connected to the steam generator.

[0011] As a further embodiment of the present invention, it also includes a feeding hopper and a feeder. The feeding hopper is used to collect steel slag that has been cooled to 800°C after being processed by the crushing rollers, and the feeder transports it.

[0012] As a further embodiment of the present invention: the feeding end of the drum heat exchanger is fixedly connected to a power screen through a feeding bin. The power screen is located below the discharge end of the feeder. The power screen is used to filter steel slag larger than 60mm and discharge steel slag larger than 60mm into a slag tank below the power screen.

[0013] As a further embodiment of the present invention: the inner wall of the drum heat exchanger is alternately fitted with spiral lifting plates and wear-resistant liners.

[0014] A method for using a segmented steel slag waste heat recovery system:

[0015] Includes: S1: High-temperature steel slag is laid on the surface of the crushing bed. The crushing vehicle moves horizontally on the surface of the crushing bed. The crushing roller rotates or remains stationary on the crushing vehicle to crush and push the steel slag with a temperature higher than 1000℃. During the rotation of the crushing roller, the steel slag pile is dispersed and individual pieces are broken. A large amount of hot air is generated in the steel slag dispersion area and rises into the interior of the surrounding hood. Liquid enters through the demineralized water conveying end. After moving around the perimeter of the surrounding hood, the height is raised. The coolant temperature is the lowest and the hot air temperature is the highest in the area at the bottom of the hot air heat exchange tube. At this time, the temperature exchange efficiency of the bottom hot air heat exchange tube is efficient. As the height increases, the temperature exchange efficiency gradually decreases. Finally, the hot air is gathered by the gathering hood and achieves the final temperature exchange with the hot air heat exchange tube inside the gathering hood. After running for 30-40 minutes, the temperature of the granulated steel slag drops to 800℃. Then, it is transferred to the slag pot by the slag pushing operation and transported to the drum heat exchanger for further processing.

[0016] S2: The heated liquid discharged from the hot gas heat exchange kit of steel slag crushing enters the water tank and is then transported to the steam generator through the water tank.

[0017] S3: The feeding hopper and feeder work together to transport 800℃ steel slag to the power screen, and the power screen removes steel slag larger than 60mm. Steel slag larger than 60mm enters the slag hopper below the power screen. The steel slag after screening enters the drum heat exchanger. The inlet and outlet are for liquid inlet and liquid outlet respectively. The waste heat generated by the drum heat exchanger is absorbed by the waste heat exchange hood. The low temperature water discharged from the downcomer exchanges heat with the drum heat exchanger for a second time through the waste heat exchange hood, continuously removing heat from the steel slag and achieving stable cooling. The heated liquid discharged through the spiral guide heat exchange tube of the waste heat exchange hood returns to the steam generator.

[0018] S4: Saturated or superheated steam in the steam generator is delivered to the power screen for power generation or heating.

[0019] As a further embodiment of the present invention, in step S11: the hot gas heat exchange tube surrounds the periphery of the partition rib plate and is close to the outer wall of the partition rib plate. The hot gas or steel slag generated by the crushing roller comes into contact with the partition rib plate and achieves heat exchange.

[0020] As a further embodiment of the present invention, step S31: the spiral lifting plates on the inner wall of the drum heat exchanger push the steel slag to move axially, and continuously lift and drop the steel slag during rotation, thereby increasing the contact area between the steel slag and the inner wall of the drum heat exchanger.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] This system utilizes the rising heat generated by the crushing and lifting of steel slag to achieve a top-mounted high-temperature heat exchange. It effectively utilizes the temperature of the high-temperature steel slag while avoiding direct contact with it. Furthermore, it leverages the high-temperature air generated inside the slag pile after lifting for rapid heat exchange, improving heat exchange efficiency and simplifying the structure. It can be upgraded onto existing crushing vehicles. Because the steel slag crushing heat exchange kit is not integrated with the steel slag structure, its stable operation is guaranteed, meeting practical application requirements and eliminating the need to overcome the impact of contact with high-temperature steel slag.

[0023] Based on the above advantages, it integrates steel slag cooling, crushing, grading and waste heat recovery functions, which significantly simplifies the process flow. The synchronous waste heat recovery in the low temperature section realizes the continuous and coordinated recovery of waste heat in the high temperature section and the low temperature section, which improves the overall thermal energy utilization efficiency. By expanding the heat exchange area and optimizing the heat transfer path, the system waste heat recovery rate can reach more than 85%, which is more than 25% higher than the traditional process. The recovered heat energy can be used for power generation, heating or other industrial purposes, which greatly reduces the energy consumption of enterprises. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a steel slag crushing hot air heat exchange kit in a segmented steel slag waste heat recovery system.

[0026] Figure 2 This is a top view cross-sectional schematic diagram of a steel slag crushing hot air heat exchange kit in a segmented steel slag waste heat recovery system.

[0027] Figure 3 This is a schematic diagram of a drum heat exchanger in a segmented steel slag waste heat recovery system.

[0028] Figure 4 This is a schematic diagram of the connection of a steam generator in a segmented steel slag waste heat recovery system.

[0029] In the diagram: 100, Water tank; 200, Steam generator; 201, Downcomer; 300, Steam network; 1, Steel slag crushing hot air heat exchange kit; 11, Enclosure cover; 111, Separating ribs; 112, Air gathering trough; 12, Gathering cover; 13, Hot air heat exchange tube; 131, Demineralized water conveying end; 132, Demineralized water return end; 133, Peripheral part; 2, Drum heat exchanger; 21, Feed bin; 22, Water inlet; 23, Water outlet; 24, Slag discharge port; 3, Power screen; 4, Feed bin; 5, Feeder; 6, Waste heat exchange cover. Detailed Implementation

[0030] Please see Figures 1-4 The first problem to be solved in this embodiment is how to efficiently utilize the thermal energy of high-temperature steel slag during the crushing process. Due to the high-temperature environment and stress conditions at the crushing contact end of the steel slag, the temperature transfer area is changed to the upper part. The specific improvements are as follows:

[0031] In this embodiment, a steel slag crushing hot air heat exchange kit 1 is installed on the crushing vehicle and surrounds the crushing roller. The steel slag crushing hot air heat exchange kit 1 consists of an upper and lower surrounding cover 11 and a gathering cover 12. The inner walls of the surrounding cover 11 and the gathering cover 12 are fixedly connected with symmetrically distributed partition ribs 111 along the axis of the crushing roller. The interior of the steel slag crushing hot air heat exchange kit 1 is divided into multiple air gathering grooves 112 corresponding to the crushing roller head by the partition ribs 111. A hot air heat exchange tube 13 is coiled inside the steel slag crushing hot air heat exchange kit 1. The demineralized water delivery end 131 of the 3 is connected to the liquid supply system. The demineralized water delivery end 131 enters from the bottom of the enclosure 11. The hot air heat exchange tube 13 circulates around the periphery of the enclosure 11 and the partition rib 111, and then bends upward to raise the height and is repeatedly coiled. The partition rib 111 after coiling has a periphery 133. Finally, the demineralized water return end 132 of the hot air heat exchange tube 13 extends out from the side of the gathering cover 12 and is connected to the water tank 100, the steam generator 200 and the steam pipeline 300 in sequence through the demineralized water return end 132.

[0032] In this embodiment, the crushing vehicle and crushing roller are existing technologies. This technical solution utilizes the crushing roller during the crushing process within the steel slag. The crushing head drives the steel slag pile to crush it while rotating, lifting the slag and forcing the air inside the pile to escape. As the hot air rises, it enters the surrounding cover 11. Simultaneously, the air-gathering groove 112 further divides the space within the surrounding cover 11, forcing the air to contact the outer wall of the partition ribs 111. The steel slag lifted by the crushing roller also easily contacts the outer wall of the partition ribs 111, ultimately exchanging heat through the perimeter 133, thus achieving efficient heat exchange. The demineralized water conveying end 131 is located below the surrounding cover 11, closer to the steel slag. The hot air generated after the steel slag pile is lifted first undergoes efficient heat exchange with the demineralized water conveying end 131, and is coupled with the temperature change of the hot air through a gradually increasing annular disc. Finally, the cooled hot air is gathered through the gathering cover 12, exchanges heat with the inner wall of the gathering cover 12, and is discharged. The heated hot water is then discharged through the demineralized water return end 132.

[0033] This technical solution utilizes the rising effect of hot air generated after steel slag crushing and hoisting to achieve top-mounted high-temperature heat exchange. It effectively utilizes the temperature of the high-temperature steel slag while avoiding direct contact with it. Furthermore, it leverages the high-temperature air generated inside the slag pile after hoisting for rapid heat exchange, improving heat exchange efficiency and simplifying the structure. Moreover, it can be modified and installed on existing crushing vehicles. Because the steel slag crushing hot air heat exchange kit 1 is not in contact with the steel slag structure, its stable operation can be guaranteed, meeting practical application requirements and eliminating the need to overcome the impact of contact with high-temperature steel slag.

[0034] Furthermore, an exhaust fan is installed on the top of the gathering hood 12 and / or a spray water pipe is installed on the inner wall of the gathering hood 12. To increase the air output, a spray water pipe can be installed on the inner wall of the gathering hood 12. The spray water pipe sprays after the steel slag is lifted by the crushing roller, generating more high-temperature gas that exchanges heat with the steel slag crushing hot gas heat exchange kit 1, resulting in better heat exchange. Alternatively, an exhaust fan can be installed on the top of the surrounding hood 11. After the steel slag is lifted by the crushing roller, the exhaust fan drives the lower gas upward, thereby generating temperature exchange with the steel slag crushing hot gas heat exchange kit 1. The outer cover of the drum heat exchanger 2 is equipped with a waste heat exchange hood 6, which consists of a hood body and a spiral guide heat exchange tube. The spiral guide heat exchange tube is tightly fitted to the outer wall of the drum. The steam generator 200 is equipped with a downcomer 201, which is connected to the spiral guide heat exchange tube. The other end of the spiral guide heat exchange tube is connected to the steam generator 200.

[0035] The specific usage method is as follows: High-temperature steel slag is laid on the surface of the crushing bed. The crushing vehicle moves horizontally on the surface of the crushing bed. The crushing rollers rotate or remain stationary on the crushing vehicle to crush and push the steel slag with a temperature higher than 1000℃. During the rotation of the crushing rollers, the steel slag pile is dispersed and individual pieces break apart. A large amount of hot air is generated in the steel slag dispersion area and rises into the interior of the surrounding cover 11. Liquid enters through the demineralized water conveying end 131, moves around the perimeter of the surrounding cover 11, and then rises in height. The coolant temperature is lowest and the hot air temperature is highest in the lowest area of ​​the hot air heat exchange tube 13. At this time, the temperature exchange efficiency of the lowest hot air heat exchange tube 13 is very efficient. As the height increases, the temperature exchange efficiency gradually decreases, and finally... Hot air is gathered by the gathering hood 12 and finally exchanges temperature with the hot air heat exchange tube 13 inside the gathering hood 12. The hot air heat exchange tube 13 surrounds the periphery of the partition rib 111 and is close to the outer wall of the partition rib 111 through the periphery part 133. The hot air or steel slag generated by the crushing roller comes into contact with the partition rib 111 and achieves heat exchange. After running for 30-40 minutes, the temperature of the granulated steel slag drops to 800℃. Then, it is transferred to the slag pot by the slag pushing operation and transported to the drum heat exchanger 2 for further processing. The heated liquid discharged from the demineralized water return end 132 of the steel slag crushing hot air heat exchange kit 1 enters the water tank 100 and is transported to the steam generator 200 through the water tank 100.

[0036] The slag crushed by the crushing rollers enters the drum heat exchanger 2. Pipes are coiled inside the drum heat exchanger 2, and the slag is circulated through the inlet 22 and outlet 23 to achieve liquid delivery and cooling. A slag discharge port 24 is provided at one end of the drum heat exchanger 2, and a slag tank is located below the discharge port 24. A waste heat exchange hood 6 is provided on the outside of the drum heat exchanger 2. The waste heat exchange hood 6 consists of a hood body and spiral guide heat exchange tubes, which are tightly fitted to the outer wall of the drum. A downcomer 201 is provided in the steam generator 200, and the downcomer 201 connects with the spiral guide heat exchange tubes. The spiral heat exchanger tube is connected to the steam generator 200 at one end. It also includes a feeding bin 4 and a feeder 5. The feeding bin 4 is used to collect steel slag that has been cooled to 800°C after being processed by the crushing rollers and is conveyed by the feeder 5. The feeding end of the drum heat exchanger 2 is fixedly connected to a power screen 3 through the feeding bin 21. The power screen 3 is located below the discharge end of the feeder 5. The power screen 3 is used to filter steel slag larger than 60mm and discharge steel slag larger than 60mm into the slag tank below the power screen 3. Spiral lifting plates and wear-resistant liners are alternately installed on the inner wall of the drum heat exchanger 2.

[0037] The feeding hopper 4 and feeder 5 work together to transport 800℃ steel slag to the power screen 3, where steel slag larger than 60mm is removed. Slag larger than 60mm enters the slag hopper below the power screen 3. The sieved steel slag enters the drum heat exchanger 2, with inlet 22 and outlet 23 for liquid inlet and outlet, respectively. The waste heat generated by the drum heat exchanger 2 is absorbed by the waste heat exchange hood 6. Spiral lifters on the inner wall of the drum heat exchanger 2 push the steel slag axially, continuously lifting and scattering it during rotation, increasing the contact area between the steel slag and the inner wall of the drum heat exchanger 2. The low-temperature water discharged from the downcomer 201 undergoes secondary heat exchange with the drum heat exchanger 2 through the waste heat exchange hood 6, continuously removing heat from the steel slag and achieving stable cooling. The heated liquid discharged through the spiral guide heat exchanger tube of the waste heat exchange hood 6 returns to the steam generator 200. The saturated or superheated steam in the steam generator 200 is transported to the power screen 3 for power generation or heating.

[0038] In addition, the drum heat exchanger 2 is driven to rotate slowly by a transmission device, and the steel slag moves inside the drum heat exchanger 2 as it rotates. Heat transfer blades are welded to the inner wall of the drum heat exchanger 2, which serve both as guiding elements to propel the steel slag forward and as increasing its contact area and residence time with the cooling surface, thereby improving heat exchange efficiency. Under the combined action of gravity and centrifugal force, the steel slag moves along the inner wall of the drum heat exchanger 2 and the direction guided by the blades. When the drum heat exchanger 2 rotates to a specific angle, the steel slag enters from the inlet, is fully cooled, and then exits from the outlet. By adjusting the drum rotation speed and parameters such as the shape and inclination angle of the blades, the residence time and conveying speed of the steel slag in the drum heat exchanger 2 can be precisely controlled, achieving uniform cooling and stable conveying. The drum heat exchanger 2 mainly includes a rotating drum containing the steel slag and multiple heat exchange tubes arranged axially inside the drum. The heat exchange tubes are composed of annularly arranged steel pipes, connected by fins to form an integral heat exchange structure, and cooling water flows through the tube cavity. After the high-temperature steel slag processed by the roller pressing system enters the equipment, cooling water flows inside the steel pipes, exchanging heat with the slag. After absorbing heat, the water heats up and flows out, returning to the cooling device via the circulation system to cool down before re-entering the heat exchange system, forming a closed-loop cycle that continuously removes heat from the steel slag, achieving stable cooling. The inner wall of the cylinder is alternately equipped with spiral lifters and wear-resistant liners. The spiral lifters push the steel slag axially, continuously lifting and scattering it during rotation, increasing the contact area between the steel slag and the inner wall of the cylinder and the heat exchange surface, enhancing heat transfer. The wear-resistant liners are made of high-chromium cast iron, possessing excellent resistance to high-temperature impact and wear resistance, effectively extending the equipment's service life.

[0039] A waste heat exchange hood 6 is located outside the drum heat exchanger 2. The waste heat exchange hood 6 includes a sealed, insulated cover, a spiral heat exchange tube, and a media circulation unit. The spiral heat exchange tube fits tightly against the outer wall of the drum heat exchanger 2, forming a closed space together with the insulated cover. The heat exchange medium can be either heat transfer oil or demineralized water. Driven by a transfer pump, the medium flows within the heat exchange tube, absorbing the waste heat transferred from the drum through heat conduction. Temperature and pressure sensors monitor the medium status in real time, and the control system dynamically adjusts the transfer pump speed based on the feedback data to ensure a stable and efficient heat exchange process.

[0040] The feeding equipment is used to uniformly and securely feed high-temperature steel slag into the drum heat exchanger 2, preventing the leakage of high-temperature flue gas. This mechanism consists of a feeding hopper 4, a feeder 5, a dynamic screen 3, and the drum heat exchanger 2. The feeding hopper 4 receives the steel slag processed in the high-temperature section; its main structure is made of thickened heat-resistant steel plate, providing excellent high-temperature load-bearing capacity. The feeder 5 ensures uniform material distribution, and the dynamic screen 3 removes excessively large steel slag particles, ensuring that the particle size of the steel slag entering the drum heat exchanger does not exceed 60mm, thereby guaranteeing uniform material distribution within the drum and improving heat exchange efficiency.

[0041] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A segmented steel slag waste heat recovery system, characterized in that: The system includes a steel slag crushing hot air heat exchange kit (1) installed on the crushing vehicle and surrounding the crushing roller. The steel slag crushing hot air heat exchange kit (1) consists of an upper and lower surrounding cover (11) and a gathering cover (12). The inner walls of the surrounding cover (11) and the gathering cover (12) are fixedly connected with symmetrically distributed partition ribs (111) along the axis of the crushing roller. The interior of the steel slag crushing hot air heat exchange kit (1) is divided into multiple air gathering grooves (112) corresponding to the crushing roller head by the partition ribs (111). The interior of the steel slag crushing hot air heat exchange kit (1) is equipped with a hot air heat exchange tube (13). The hot air heat exchange tube (13) is used for desalination. The water delivery end (131) is connected to the liquid supply system. The demineralized water delivery end (131) enters from the bottom of the enclosure (11). The hot air heat exchange tube (13) circulates around the periphery of the enclosure (11) and the partition rib (111) once and then bends upward to raise the height and is repeatedly coiled. The partition rib (111) after coiling has a periphery (133). Finally, the demineralized water return end (132) of the hot air heat exchange tube (13) extends out from the side above the gathering cover (12) and is connected to the water tank (100), steam generator (200) and steam network (300) in sequence through the demineralized water return end (132).

2. The segmented steel slag waste heat recovery system according to claim 1, characterized in that: The top of the gathering cover (12) is provided with an exhaust fan and / or the inner wall of the gathering cover (12) is provided with a spray pipe.

3. The segmented steel slag waste heat recovery system according to claim 1, characterized in that: The slag crushed by the crushing roller enters the inside of the drum heat exchanger (2). The inside of the drum heat exchanger (2) is equipped with pipelines and connects with the circulating cooling equipment through the inlet (22) and outlet (23) to realize liquid delivery, liquid cooling and circulation. One end of the drum heat exchanger (2) is provided with a slag discharge port (24), and a slag tank is provided below the slag discharge port (24).

4. A segmented steel slag waste heat recovery system according to claim 3, characterized in that: The outer cover of the drum heat exchanger (2) is provided with a waste heat exchange cover (6), which consists of a cover body and a spiral heat exchange tube. The spiral heat exchange tube is tightly attached to the outer wall of the drum. The steam generator (200) is provided with a downcomer (201), which is connected to the spiral heat exchange tube. The other end of the spiral heat exchange tube is connected to the steam generator (200).

5. A segmented steel slag waste heat recovery system according to claim 3, characterized in that: It also includes a feeding bin (4) and a feeder (5). The feeding bin (4) is used to collect steel slag that has been cooled to 800°C after being processed by the crushing rollers, and is conveyed by the feeder (5).

6. A segmented steel slag waste heat recovery system according to claim 5, characterized in that: The feeding end of the drum heat exchanger (2) is fixedly connected to a power screen (3) through a feeding bin (21). The power screen (3) is located below the discharge end of the feeder (5). The power screen (3) is used to filter steel slag larger than 60mm and discharge steel slag larger than 60mm into the slag tank below the power screen (3).

7. A segmented steel slag waste heat recovery system according to claim 3, characterized in that: The inner wall of the drum heat exchanger (2) is alternately fitted with spiral lifting plates and wear-resistant liners.

8. The method of using a segmented steel slag waste heat recovery system according to any one of claims 1-7, characterized in that: include: S1: High-temperature steel slag is laid on the surface of the crushing bed. The crushing car moves horizontally on the surface of the crushing bed. The crushing roller rotates or stays on the crushing car to crush and push the steel slag with a temperature higher than 1000℃. During the rotation of the crushing roller, the steel slag pile is dispersed and the individual pieces are split. A large amount of hot air is generated in the steel slag dispersion area and rises into the interior of the surrounding cover (11). The liquid enters through the demineralized water conveying end (131) and moves around the perimeter of the surrounding cover (11) and then rises in height. The coolant temperature in the lowest area of ​​the hot air heat exchange tube (13) is the lowest and the hot air temperature is the highest. At this time, the lowest hot air heat exchange tube (13) has efficient temperature exchange. As the height increases, the temperature exchange efficiency gradually decreases. Finally, the hot air is gathered by the gathering cover (12) and achieves the final temperature exchange with the hot air heat exchange tube (13) inside the gathering cover (12). After running for 30-40 minutes, the temperature of the granulated steel slag drops to 800℃. Then, it is transferred to the slag tank by the slag pushing operation and transported to the drum heat exchanger (2) for subsequent processing. S2: The heated liquid discharged from the steel slag crushing hot gas heat exchange kit (1) enters the water tank (100) and is transported to the steam generator (200) through the water tank (100). S3: The feeding bin (4) and the feeder (5) work together to transport the 800℃ steel slag to the power screen (3), and the power screen (3) removes steel slag larger than 60mm. The steel slag larger than 60mm enters the slag tank below the power screen (3). The steel slag after screening enters the drum heat exchanger (2). The inlet (22) and outlet (23) are for liquid inlet and liquid outlet respectively. The waste heat generated by the drum heat exchanger (2) is absorbed by the waste heat heat exchange cover (6). The low temperature water discharged from the downcomer (201) exchanges heat with the drum heat exchanger (2) twice through the waste heat heat exchange cover (6), continuously removing the heat of the steel slag and achieving stable cooling. The heated liquid discharged through the spiral guide heat exchange tube of the waste heat heat exchange cover (6) returns to the steam generator (200). S4: Saturated or superheated steam in the steam generator (200) is delivered to the steam network (300) for power generation or heating.

9. The method of using a segmented steel slag waste heat recovery system according to claim 8, characterized in that: Step S11: The hot gas heat exchange tube (13) surrounds the periphery of the partition rib plate (111) and is close to the outer wall of the partition rib plate (111) through the periphery part (133). The hot gas or steel slag generated by the crushing roller comes into contact with the partition rib plate (111) and achieves heat exchange.

10. The method of using a segmented steel slag waste heat recovery system according to claim 9, characterized in that: Step S31: The spiral lifting plates on the inner wall of the drum heat exchanger (2) push the steel slag to move along the axial direction and continuously lift and drop the steel slag during the rotation process, increasing the contact area between the steel slag and the inner wall of the drum heat exchanger (2).

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