Waste heat recovery system for full-process dry cooling of molten steel slag

Abstract

The invention discloses a waste heat recovery system for full-process dry cooling of molten steel slag, and relates to the technical field of steel slag waste heat recovery, the waste heat recovery system comprises waste heat recovery equipment and a waste heat recovery pipeline matched with the waste heat recovery equipment, the waste heat recovery equipment is divided into high-temperature waste heat recovery equipment, medium-temperature waste heat recovery equipment and low-temperature waste heat recovery equipment, the system is reasonable in design and simple in principle, full-process cooling treatment of molten stainless steel slag is achieved, waste heat recovery is carried out, the recovery efficiency is extremely high, the system has the characteristics of energy conservation, environmental protection and mechanization, water resource waste is not involved in the cooling and waste heat recovery process, closed treatment is adopted, and the system is suitable for large-scale popularization and application. Dust overflow is avoided, dust is subjected to dry treatment through the flue gas purification device, the defect of wet dust removal is overcome, manual transfer is not needed in the waste heat recovery process, the manual labor intensity and cost are reduced, meanwhile, the risk of heavy metal leaching is avoided, and the device is suitable for large-scale popularization.

Description

Technical Field

[0001] The present invention relates to the technical field of steel slag waste heat recovery, and particularly relates to a waste heat recovery system for dry cooling molten steel slag in the whole process. Background Art

[0002] In the booming year of 2023, the Chinese stainless steel industry still demonstrated strong productivity, with an annual stainless steel output reaching as high as 36 million tons, showing a quite remarkable scale. Along with it, the quantity of stainless steel slag is also not to be underestimated, reaching approximately 10 million tons, and the total amount of steel slag is about 120 million tons. At present, in the production process field of stainless steel, the combined method of electric furnace and AOD refining has emerged and become the dominant key means. Notably, more than 80% of stainless steel products rely on AOD refining technology in the production process, indicating the high popularity of this technology in the industry.

[0003] It is worth noting that as a by-product in the production of stainless steel, AOD slag contains a special component of dicalcium silicate. When AOD slag leaves the high-temperature environment and starts the cooling process, α-C 2 S is successively transformed into β-C 2 S and γ-C 2 S, with the volume increasing, thus causing a sharp rise in internal stress. When the stress exceeds the bearing limit, the steel slag will be pulverized, and a large amount of dust diffused in the air will be generated, bringing many challenges to the production environment and subsequent treatment.

[0004] When the stainless steel slag is just out of the furnace, it is in a molten liquid state with a temperature ranging from 1200°C to 1500°C. If the large amount of heat contained in it can be reasonably developed, it will undoubtedly open up a new path for the comprehensive utilization of energy.

[0005] At present, the primary treatment processes for stainless steel slag mainly include air cooling + immersion treatment, air cooling + hot splashing treatment, drum method, etc. The main problems of the above various treatment processes are as follows:

[0006] 1. Air cooling + immersion treatment. This treatment process is simple and easy to operate, and is currently the most widely used. The treatment process takes a long time, requires a large number of slag pots, has a large slag yard area, waste steam overflows, and serious dust is raised during the process of tipping and transferring the slag pots.

[0007] 2. Air cooling + hot splashing treatment. The treatment process takes a long time, has a large slag yard area, waste steam overflows, and serious dust is raised during the process of tipping and transferring the slag pots.

[0008] 3. Drum method. The molten steel slag is placed in a rotating drum, and the steel slag is granulated by quickly spraying water and continuous impact of the crushing medium. The equipment is complex, the operation and maintenance difficulty is large, and the energy consumption is high.

[0009] The above three treatment processes still have the problems of high water consumption in wet treatment, consuming 0.8 - 1.2 tons of water for treating one ton of steel slag, unable to recover waste heat, high water content in steel slag, low activity of tail slag, and the risk of leaching of heavy metal ions such as hexavalent chromium in tail slag. A large number of personnel are required during the transportation of steel slag. Summary of the Invention

[0010] In view of the problems disclosed in the background art, the present invention provides a waste heat recovery system for dry cooling molten steel slag in the whole process.

[0011] To achieve the above object, the present invention provides the following technical solutions:

[0012] A waste heat recovery system for dry cooling molten steel slag in the whole process, which is used for waste heat recovery treatment of stainless steel slag, especially suitable for waste heat recovery treatment of dry cooling in the whole process of molten stainless steel slag. It is characterized in that it includes waste heat recovery equipment and waste heat recovery pipelines cooperating with the waste heat recovery equipment;

[0013] The waste heat recovery equipment: is divided into high-temperature waste heat recovery equipment, medium-temperature waste heat recovery equipment and low-temperature waste heat recovery equipment according to the temperature of the stainless steel slag to be processed, and is arranged in sequence according to the process route;

[0014] The waste heat recovery pipeline: includes a waste heat boiler and a waste heat recovery pipeline. Among them, the waste heat recovery pipeline is divided into a liquid-cooled waste heat recovery pipeline and an air-cooled waste heat recovery pipeline according to the waste heat recovery medium;

[0015] The liquid-cooled waste heat recovery pipeline includes a liquid-cooled waste heat recovery inlet pipe and a liquid-cooled waste heat recovery outlet pipe. The high-temperature waste heat recovery equipment and the medium-temperature waste heat recovery equipment are respectively connected to the waste heat boiler through the liquid-cooled waste heat recovery inlet pipe to receive the coolant, and are respectively connected to the waste heat boiler through the liquid-cooled waste heat recovery outlet pipe to discharge the coolant after absorbing heat;

[0016] The air-cooled waste heat recovery pipeline includes an air-cooled waste heat recovery inlet pipe and an air-cooled waste heat recovery outlet pipe. The high-temperature waste heat recovery equipment and the medium-temperature waste heat recovery equipment are respectively connected to the waste heat boiler through the air-cooled waste heat recovery inlet pipe to input air, and are respectively connected to the waste heat boiler through the air-cooled waste heat recovery outlet pipe to input the hot air after absorbing heat.

[0017] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process. Among them, it further includes a steel slag transfer and tipping device, a steel slag crushing device, and a steel slag storage bin. The steel slag transfer and tipping device is used for the transfer and tipping of molten high-temperature steel slag. The steel slag crushing device is used for crushing medium-temperature stainless steel slag that has completed the first waste heat recovery and solidification. The steel slag storage bin is used for storing stainless steel slag that has completed the waste heat recovery in the whole process. According to the process route, the steel slag transfer and tipping device is arranged before the high-temperature waste heat recovery equipment, the steel slag crushing device is arranged between the high-temperature waste heat recovery equipment and the medium-temperature waste heat recovery equipment, and the steel slag storage bin is arranged after the low-temperature waste heat recovery equipment.

[0018] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process. Among them, the steel slag transfer and tipping device includes a gantry walking device, a tipping mechanism, and a slag pot. The slag pot is rotatably arranged on the gantry walking device. The tipping mechanism includes a tipping motor, a driving gear, and a transmission gear. The tipping motor is fixedly installed on the gantry walking device. The driving gear is fixedly connected to the transmission shaft of the tipping motor. The transmission gear is fixedly connected to the shaft of the rotatably arranged slag pot.

[0019] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process. Among them, the gantry walking device is a traveling crane, and a weighing module for weighing the weight of the slag pot is arranged thereon. The weighing module communicates with the tipping motor to control the running speed of the tipping motor.

[0020] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process. Among them, a heat-resistant and heat-insulating steel slag buffer device is arranged between the high-temperature waste heat recovery equipment and the steel slag crushing device.

[0021] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process. Among them, the steel slag crushing device is a water-cooled crusher. The waste heat recovery pipeline further includes a water-cooled waste heat recovery pipeline, which includes a water-cooled waste heat recovery inlet pipe and a water-cooled waste heat recovery outlet pipe. The steel slag crushing device and the low-temperature waste heat recovery equipment are respectively connected to the water-cooled waste heat recovery inlet pipe to receive cold water, and are respectively connected to the water-cooled waste heat recovery outlet pipe to discharge hot water.

[0022] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process. Among them, the high-temperature waste heat recovery equipment includes a shell wall frame, an openable heat extraction cover shell, and a heat exchange cooling bed. The heat exchange cooling bed is connected to the liquid-cooled waste heat recovery inlet pipe and the liquid-cooled waste heat recovery outlet pipe. Wind holes are arranged at the front and rear ends of the shell wall frame for connecting with the air-cooled waste heat recovery inlet pipe and the air-cooled waste heat recovery outlet pipe.

[0023] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process, wherein both the medium-temperature waste heat recovery device and the low-temperature waste heat recovery device adopt the drum cooler in a rotary kiln slag cooling system capable of waste heat recovery as described in the application number 202423178859.X, including a cooling circulation inlet and a cooling circulation outlet. The cooling circulation inlet is connected to the liquid-cooled waste heat recovery inlet pipe, the cooling circulation outlet is connected to the liquid-cooled waste heat recovery outlet pipe, and the medium-temperature waste heat recovery device is connected to the air-cooled waste heat recovery inlet pipe and the air-cooled waste heat recovery outlet pipe.

[0024] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process, wherein the low-temperature waste heat recovery device is connected to the air-cooled waste heat recovery inlet pipe and the flue gas purification device, and the flue gas purification device is a bag filter.

[0025] The above-mentioned waste heat recovery system for dry cooling molten steel slag in the whole process, wherein an automatic feeding device for adding modifiers is provided on the steel slag transfer tipping device. The automatic feeding device is installed at the position of the slag pot. The waste heat boiler is connected to the heat storage device, and the heat storage device is one or more of a steam accumulator, a molten salt accumulator, and a solid accumulator.

[0026] The technical effects and advantages of the present invention:

[0027] The present invention discloses a waste heat recovery system for dry cooling molten steel slag in the whole process, which relates to the technical field of steel slag waste heat recovery. It includes waste heat recovery devices and waste heat recovery pipelines that cooperate with the waste heat recovery devices. Among them, the waste heat recovery devices are divided into high-temperature waste heat recovery devices, medium-temperature waste heat recovery devices, and low-temperature waste heat recovery devices. The waste heat recovery pipelines include waste heat boilers and waste heat recovery pipelines. The present invention is reasonably designed and has a simple principle. It realizes the whole-process cooling treatment of molten stainless steel slag, can effectively recover waste heat, has a very high recovery efficiency, and has the characteristics of energy conservation, environmental protection, and mechanization. The cooling and waste heat recovery processes do not involve waste of water resources, and it is a closed treatment without dust overflow. The dust is treated by the dry method of the flue gas purification device, avoiding the defects of wet dust removal. During the waste heat recovery process, manual transfer is not required, greatly reducing the manual labor intensity and labor cost. At the same time, there is no risk of heavy metal leaching, meeting the requirements and standards of dry treatment, and is suitable for large-scale promotion. Brief Description of the Drawings

[0028] Figure 1 It is the schematic diagram of the principle of the present invention.

[0029] Figure 2 It is the cross-sectional schematic diagram of the high-temperature waste heat recovery device and the steel slag transfer tipping device.

[0030] Figure 3 It is the schematic diagram of the medium-temperature waste heat recovery device / low-temperature waste heat recovery device.

[0031] Among them, the reference numerals are as follows: 1. High-temperature waste heat recovery equipment; 2. Medium-temperature waste heat recovery equipment; 3. Low-temperature waste heat recovery equipment; 4. Waste heat boiler; 5. Liquid-cooled waste heat recovery pipeline; 6. Air-cooled waste heat recovery pipeline; 7. Water-cooled waste heat recovery pipeline; 8. Steel slag transfer and tipping device; 9. Steel slag crushing device; 10. Steel slag storage bin; 11. Gantry walking device; 12. Dumping mechanism; 13. Slag ladle; 14. Dumping motor; 15. Make-up water pipeline; 16. Driving gear; 17. Driven gear; 18. Steel slag buffer device; 19. Shell wall frame; 20. Heat extraction housing; 21. Heat exchange cooling bed; 22. Cooling cycle inlet; 23. Cooling cycle outlet; 24. Flue gas purification device; 25. Automatic feeding device; 26. Heat storage equipment; 27. Flue gas treatment pipeline; 501. Liquid-cooled waste heat recovery inlet pipe; 502. Liquid-cooled waste heat recovery outlet pipe; 601. Air-cooled waste heat recovery inlet pipe; 602. Air-cooled waste heat recovery outlet pipe; 701. Water-cooled waste heat recovery inlet pipe; 702. Water-cooled waste heat recovery outlet pipe. Specific embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment 1

[0034] As shown in the figure, this embodiment discloses a waste heat recovery system for dry cooling molten steel slag in the whole process, which is used for waste heat recovery treatment of stainless steel slag, especially suitable for waste heat recovery treatment of dry cooling in the whole process of molten stainless steel slag, including waste heat recovery equipment and waste heat recovery pipelines cooperating with the waste heat recovery equipment;

[0035] The waste heat recovery equipment: According to the temperature of the stainless steel slag to be processed, it is divided into high-temperature waste heat recovery equipment 1, medium-temperature waste heat recovery equipment 2 and low-temperature waste heat recovery equipment 3, which are used for efficient cooling and waste heat recovery of stainless steel slag at different temperatures. The high-temperature waste heat recovery equipment 1, medium-temperature waste heat recovery equipment 2 and low-temperature waste heat recovery equipment 3 are arranged in sequence according to the process route. Before the high-temperature waste heat recovery equipment 1 processes, the temperature of the stainless steel slag is 1200°C to 1500°C, and after processing, the temperature of the stainless steel slag is 700°C to 1000°C. After the medium-temperature waste heat recovery equipment 2 processes, the temperature of the stainless steel slag is not higher than 400°C, and after the low-temperature waste heat recovery equipment 3 processes, the temperature of the stainless steel slag is not higher than 150°C;

[0036] The waste heat recovery pipeline: It includes a waste heat boiler 4 and a waste heat recovery pipeline. Among them, a coolant is stored in the waste heat boiler 4. The waste heat recovery pipeline is divided into a liquid-cooled waste heat recovery pipeline 5 and an air-cooled waste heat recovery pipeline 6 according to the waste heat recovery medium.

[0037] Among them, the coolant in the liquid-cooled waste heat recovery pipeline 5 is saturated water. It includes a liquid-cooled waste heat recovery inlet pipe 501 and a liquid-cooled waste heat recovery outlet pipe 502. The high-temperature waste heat recovery device 1 and the medium-temperature waste heat recovery device 2 are respectively connected to the waste heat boiler 4 through the liquid-cooled waste heat recovery inlet pipe 501 to receive the coolant, and are respectively connected to the waste heat boiler 4 through the liquid-cooled waste heat recovery outlet pipe 502 to discharge the coolant after heat absorption; the coolant vaporizes after heat absorption and is sent back to the waste heat boiler 4, waiting to be utilized or stored.

[0038] The air-cooled waste heat recovery pipeline 6 includes an air-cooled waste heat recovery inlet pipe 601 and an air-cooled waste heat recovery outlet pipe 602. The high-temperature waste heat recovery device 1 and the medium-temperature waste heat recovery device 2 are respectively connected to the waste heat boiler 4 through the air-cooled waste heat recovery inlet pipe 601 to input air, and are respectively connected to the waste heat boiler 4 through the air-cooled waste heat recovery outlet pipe 602 to input the hot air after heat absorption; the coolant vaporizes after heat exchange with the hot air and waits to be utilized or stored.

[0039] The waste heat recovery system for dry cooling molten steel slag in the whole process of this embodiment further includes a steel slag transfer and tipping device 8, a steel slag crushing device 9 and a steel slag storage bin 10. Among them, the steel slag transfer and tipping device 8 is used for the transfer and tipping of molten high-temperature stainless steel slag, and makes the stainless steel slag fall into the high-temperature waste heat recovery device 1. The steel slag crushing device 9 is used for crushing the medium-temperature stainless steel slag that has completed the first waste heat recovery and solidified (cooled by the high-temperature waste heat recovery device 1), so that the stainless steel slag can efficiently cool and exchange heat in the medium-temperature waste heat recovery device 2. The steel slag storage bin 10 is used for storing the stainless steel slag that has completed the whole process of waste heat recovery (cooled by the high-temperature waste heat recovery device 1, the medium-temperature waste heat recovery device 2 and the low-temperature waste heat recovery device 3). According to the process route, the steel slag transfer and tipping device 8 is arranged before the high-temperature waste heat recovery device 1, the steel slag crushing device 9 is arranged between the high-temperature waste heat recovery device 1 and the medium-temperature waste heat recovery device 2, and the steel slag storage bin 10 is arranged after the low-temperature waste heat recovery device 3. In addition, the transfer of steel slag between the high-temperature waste heat recovery device 1, the steel slag crushing device 9, the medium-temperature waste heat recovery device 2, the low-temperature waste heat recovery device 3 and the steel slag storage bin 10 is realized through a closed transfer device to avoid dust escape. This transfer device can be a high-temperature chain conveyor and / or a scale bucket conveyor.

[0040] Embodiment 2

[0041] A waste heat recovery system for dry cooling molten steel slag in the whole process of this embodiment. Among them, the steel slag transfer and tipping device 8 includes a gantry walking device 11, a tipping mechanism 12 and a slag pot 13. The slag pot 13 is rotatably arranged on the gantry walking device 11. The tipping mechanism 12 includes a tipping motor 14, a driving gear 16 and a transmission gear 17. The tipping motor 14 is fixedly installed on the gantry walking device 11. The driving gear 16 is fixedly connected to the transmission shaft of the tipping motor 14. The transmission gear 17 is fixedly connected to the shaft of the rotatably arranged slag pot 13. During operation, the slag pot 13 carries molten stainless steel slag and moves through the gantry walking device 11. When the slag pot 13 moves above the high-temperature waste heat recovery device 1, the slag pot 13 actively rotates through the tipping mechanism 12 to perform a tipping action. At this time, the gantry walking device 11 continues to work, so that the molten stainless steel slag continuously and accurately falls into the high-temperature waste heat recovery device 1.

[0042] Among them, the gantry walking device 11 is a traveling crane. In order to evenly spread the molten stainless steel slag in the high-temperature waste heat recovery device 1 (to improve the cooling and heat exchange efficiency), a weighing module is arranged on the gantry walking device 11 in this embodiment. This weighing module can effectively and accurately track the overall weight and changes of the slag pot 13 and the molten stainless steel slag therein (that is, the load weight and changes of the gantry walking device 11), and through its communication interaction with the tipping motor 14, accurately control the running speed of the tipping motor 14 and control the tipping amount of the stainless steel slag.

[0043] In addition, in order to achieve continuous cooling and waste heat recovery, in this embodiment, a heat-resistant and heat-insulating steel slag buffer device 18 is arranged between the high-temperature waste heat recovery device 1 and the steel slag crushing device 9 to ensure continuous feeding of the subsequent waste heat recovery device.

[0044] Embodiment 3

[0045] A waste heat recovery system for dry cooling molten steel slag in the whole process of this embodiment. Among them, the waste heat recovery pipeline further includes a water-cooled waste heat recovery pipeline 7. The water-cooled waste heat recovery pipeline 7 includes a water-cooled waste heat recovery inlet pipe 701 and a water-cooled waste heat recovery outlet pipe 702. In order to ensure the normal operation of the steel slag crushing device 9 and at the same time avoid heat waste, the steel slag crushing device 9 in this embodiment adopts a water-cooled crusher. The steel slag crushing device 9 and the low-temperature waste heat recovery device 3 are respectively connected to the water-cooled waste heat recovery inlet pipe 701 to receive cold water and are respectively connected to the water-cooled waste heat recovery outlet pipe 702 to discharge hot water. The hot water in this part can be directly used in the factory area (such as for heating) or can be used as a compensating coolant and transported to the waste heat boiler 4. The waste heat boiler 4 is also provided with a makeup water pipeline 15 for supplementing the coolant.

[0046] Embodiment 4

[0047] A waste heat recovery system for fully dry cooling molten steel slag in this embodiment, wherein the high-temperature waste heat recovery device includes a shell wall frame 19, an openable heat extraction cover 20 and a heat exchange cooling bed 21, which has the functions of wall heat exchange and radiation heat exchange. Among them, the heat exchange cooling bed 21 is connected to the liquid-cooled waste heat recovery inlet pipe 501 and the liquid-cooled waste heat recovery outlet pipe 502. In addition, an air-cooled heat exchange function is added. In this embodiment, air holes are provided at the front and rear ends of the shell wall frame 19 for connecting with the air-cooled waste heat recovery inlet pipe 601 and the air-cooled waste heat recovery outlet pipe 602 to achieve air-cooled and convective heat exchange effects.

[0048] In addition, both the medium-temperature waste heat recovery device 2 and the low-temperature waste heat recovery device 3 adopt a drum cooler in a rotary kiln slag cooling system capable of waste heat recovery such as the application number 202423178859.X, which can be effectively used for the cooling and waste heat recovery of small particle size steel slag. Specifically, it includes a cooling circulation inlet 22 and a cooling circulation outlet 23. The cooling circulation inlet 22 is connected to the liquid-cooled waste heat recovery inlet pipe 501, and the cooling circulation outlet 23 is connected to the liquid-cooled waste heat recovery outlet pipe 502. Similarly, air holes are also provided at the front and rear ends of the medium-temperature waste heat recovery device 2 for connecting with the air-cooled waste heat recovery inlet pipe 601 and the air-cooled waste heat recovery outlet pipe 602 to achieve air-cooled and convective heat exchange effects.

[0049] Considering the pulverization of stainless steel slag due to stress after the temperature of stainless steel slag decreases, in this embodiment, air holes are provided at the front and rear ends of the low-temperature waste heat recovery device 3 for connecting with the air-cooled waste heat recovery inlet pipe 601 and the flue gas purification device 24. The flue gas purification device 24 is a bag filter for dry treatment of dust. In addition, the waste heat boiler 4 is connected to the flue gas purification device 24 for discharging the low-temperature air after heat exchange.

[0050] Embodiment 5

[0051] A waste heat recovery system for fully dry cooling molten steel slag in this embodiment, wherein an automatic feeding device 25 for adding a modifier is provided on the steel slag transfer tipping device 8 to reduce the free calcium oxide content of the tail slag and reduce the pulverization degree of stainless steel slag (the modifier is mostly substances with high silicon content such as fly ash and photovoltaic panel powder). The automatic feeding device 25 is installed at the position of the slag pot 13. In addition, the waste heat boiler 4 is connected to the heat storage device 26 for heat storage and reuse. The heat storage device 26 is one or more of a steam accumulator, a molten salt accumulator, and a solid accumulator.

[0052] Based on the solutions of Embodiments 1-5, it is obvious that a waste heat recovery system for fully dry cooling molten steel slag disclosed in the embodiment can not only be used for the cooling and waste heat recovery of stainless steel slag, but also be applied to the cooling and waste heat recovery treatment of most other types of steel slag.

[0053] Example 6

[0054] A waste heat recovery system for dry cooling molten stainless steel slag in the whole process of this embodiment further includes a flue gas treatment pipeline 27, which is connected to the medium-temperature waste heat recovery device 2 and the low-temperature waste heat recovery device 3, and injects flue gas containing carbon dioxide into them (the flue gas containing carbon dioxide is taken from a steel plant, and the tail gas is collected nearby, and the sources are lime kiln tail gas, gas boiler tail gas, coal-fired boiler tail gas, etc.). The flue gas containing carbon dioxide introduced into the medium-temperature waste heat recovery device 2 and the low-temperature waste heat recovery device 3 can effectively react with the free calcium oxide in the stainless steel slag to form carbonate, which can not only effectively control the pulverization of the stainless steel slag, but also facilitate the subsequent comprehensive utilization of the stainless steel slag. At the same time, the purpose of carbon capture and flue gas treatment is also achieved;

[0055] In addition, while the flue gas containing carbon dioxide entering the medium-temperature waste heat recovery device 2 reacts, it mixes with the introduced air and absorbs heat, and enters the waste heat boiler 4 through the air-cooled waste heat recovery outlet pipe 602 to participate in the air-cooled waste heat recovery process, and is finally discharged through the flue gas purification device 24; while the flue gas containing carbon dioxide entering the low-temperature waste heat recovery device 3 reacts, it mixes with the introduced air and is finally introduced into the flue gas purification device 24 and is safely discharged.

[0056] Based on the content of the above embodiments, it is not difficult to see that the present invention realizes the whole-process cooling treatment of molten stainless steel slag, effectively recovers waste heat, has a very high recovery efficiency, has the characteristics of energy saving, environmental protection and mechanization. The cooling and waste heat recovery processes do not involve waste of water resources, and are closed treatment without dust overflow. The dust is treated by dry method through the flue gas purification device, avoiding the defects of wet dust removal. During the waste heat recovery process, there is no need for manual transfer, greatly reducing the labor intensity and labor cost of workers. At the same time, there is no risk of heavy metal leaching, meeting the requirements and standards of dry treatment, and is suitable for large-scale promotion.

[0057] In the description of the present invention, unless otherwise clearly defined and limited, the terms "set", "install", "connect", "connect", "fix" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0058] The standard parts used in the present invention can all be purchased from the market, and the special-shaped parts can be customized according to the description of the specification and the drawings.

[0059] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waste heat recovery system for full-process dry cooling of molten steel slag, characterized in that: Including waste heat recovery equipment and waste heat recovery pipelines matched with the waste heat recovery equipment; The waste heat recovery equipment is divided into high-temperature waste heat recovery equipment (1), medium-temperature waste heat recovery equipment (2) and low-temperature waste heat recovery equipment (3) according to the temperature of the steel slag to be processed, and is arranged in sequence according to the process route; The waste heat recovery pipeline comprises a waste heat boiler (4) and a waste heat recovery pipeline, wherein the waste heat recovery pipeline is divided into a liquid-cooled waste heat recovery pipeline (5) and an air-cooled waste heat recovery pipeline (6) according to the waste heat recovery medium; The liquid-cooled waste heat recovery pipeline (5) comprises a liquid-cooled waste heat recovery inlet pipe (501) and a liquid-cooled waste heat recovery outlet pipe (502); the high-temperature waste heat recovery device (1) and the medium-temperature waste heat recovery device (2) are respectively connected to the waste heat boiler (4) through the liquid-cooled waste heat recovery inlet pipe (501) to receive cooling liquid, and are respectively connected to the waste heat boiler (4) through the liquid-cooled waste heat recovery outlet pipe (502) to discharge the cooling liquid after absorbing heat; The air-cooled waste heat recovery pipeline (6) comprises an air-cooled waste heat recovery inlet pipe (601) and an air-cooled waste heat recovery outlet pipe (602); the high-temperature waste heat recovery device (1) and the medium-temperature waste heat recovery device (2) are respectively connected to the waste heat boiler (4) through the air-cooled waste heat recovery inlet pipe (601) to input air, and are respectively connected to the waste heat boiler (4) through the air-cooled waste heat recovery outlet pipe (602) to input hot air after heat absorption.

2. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 1 is characterized in that: The invention also comprises a slag transfer and tilting device (8), a slag crushing device (9) and a slag storage bin (10). According to the process route, the slag transfer and tilting device (8) is arranged before the high-temperature waste heat recovery device (1), the slag crushing device (9) is arranged between the high-temperature waste heat recovery device (1) and the medium-temperature waste heat recovery device (2), and the slag storage bin (10) is arranged after the low-temperature waste heat recovery device (3).

3. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 2 is characterized in that: The slag transport and tipping device (8) comprises a gantry-type walking device (11), a tipping mechanism (12) and a slag pot (13); the slag pot (13) is rotatably arranged on the gantry-type walking device (11); the tipping mechanism (12) comprises a tipping motor (14), a driving gear (16) and a transmission gear (17); the tipping motor (14) is fixedly mounted on the gantry-type walking device (11); the driving gear (16) is fixedly connected to the transmission shaft of the tipping motor (14); and the transmission gear (17) is fixedly connected to the shaft of the rotatably arranged slag pot (13).

4. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 3 is characterized in that: The gantry-type traveling device (11) is a crane, on which a weighing module for weighing the weight of the slag pot (13) is arranged, and the weighing module communicates and interacts with the dumping motor (14) to control the operating speed of the dumping motor (14).

5. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 3 is characterized in that: A heat-resistant and heat-insulating slag buffer device (18) is provided between the high-temperature waste heat recovery device (1) and the slag crushing device (9).

6. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 3 is characterized in that: The steel slag crushing device (9) is a water-cooled crusher, and the waste heat recovery pipeline also includes a water-cooled waste heat recovery pipeline (7), and the water-cooled waste heat recovery pipeline (7) includes a water-cooled waste heat recovery inlet pipe (701) and a water-cooled waste heat recovery outlet pipe (702). The steel slag crushing device (9) and the low-temperature waste heat recovery equipment (3) are respectively connected to the water-cooled waste heat recovery inlet pipe (701) to receive cold water, and are respectively connected to the water-cooled waste heat recovery outlet pipe (702) to discharge hot water.

7. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 1 is characterized in that: The low-temperature waste heat recovery device (3) is connected to the air-cooled waste heat recovery inlet pipe (601) and the flue gas purification device (24).

8. The waste heat recovery system for full-process dry cooling of molten steel slag according to claim 3 is characterized in that: The slag transfer and tilting device (8) is provided with an automatic feeding device (25) for adding a modifier, and the automatic feeding device (25) is installed at the slag pot (13). The waste heat boiler (4) is connected to a heat storage device (26), and the heat storage device (26) is one or more of a steam accumulator, a molten salt accumulator, and a solid accumulator.

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