A waste heat recovery device and method for brown corundum package

Abstract

The application discloses a kind of brown corundum package for waste heat recovery device and method, and the waste heat recovery device includes heat shield and cover plate, both form the closed cavity of placing package and are enclosed, and adjustable flow rate heat exchange component is arranged on the inner wall of cover plate, the effective control of heat exchange rate is realized;When waste heat is recovered, package is placed in heat shield, brown corundum molten liquid is poured into package, cover plate with adjustable flow rate heat exchange component is placed on heat shield, so that package is completely in closed cavity, the flow rate of heat exchange component is adjusted, in the initial stage of heat exchange, control heat exchange medium to be introduced at lower flow rate, flow rate gradually increases, after a period of time, maintain stable working flow rate to pass into heat exchange medium, the waste heat stored in waste heat recovery device is effectively recovered;The device can maximize the heat emitted during the cooling process under the premise of ensuring the crystallization performance of brown corundum, so as to realize the efficient use of energy.

Description

Technical Field

[0001] This invention belongs to the field of industrial waste heat recovery, and particularly relates to a waste heat recovery device and method for brown fused alumina receiving packages. Background Technology

[0002] Brown fused alumina, also known as corundum, is a synthetic corundum produced by melting and reducing bauxite, carbon materials, and iron filings in a three-phase electric arc furnace at temperatures above 2000 degrees Celsius. Brown fused alumina possesses high strength, excellent thermal conductivity, and good oxidation resistance. Its main applications are in four major fields: functional ceramics, advanced refractories, abrasives, and metallurgical raw materials. As a fundamental abrasive in industrial production, brown fused alumina is widely used across various industries due to its good grinding performance, wide applicability, and low price.

[0003] The electric furnaces commonly used in the smelting of brown fused alumina are stationary furnaces and tilting furnaces, with a usage ratio of approximately 4:3. Compared to production in stationary furnaces, after the molten brown fused alumina is heated and melted in a tilting furnace, it can be poured into a dedicated ladle, allowing for the addition of more raw materials for continuous smelting, thus enabling continuous production. After receiving the material in the tilting furnace ladle, it is moved to a cooling area for natural air cooling. Since the temperature of the molten brown fused alumina exiting the furnace can reach over 2000 degrees Celsius, natural cooling to a solid state takes a considerable amount of time (approximately 30 hours), and this natural cooling results in a significant loss of usable heat. This deteriorates the factory working environment, especially in summer, where the large amount of radiant heat can adversely affect the health of workers. Furthermore, the emission of large amounts of waste heat contradicts the principles of energy conservation, emission reduction, and low-carbon production.

[0004] Existing waste heat recovery devices in the brown fused alumina industry primarily focus on designing and modifying the tilting furnace ladle itself, including installing a water-cooled layer inside the ladle and an air-cooled device at the top. Brown fused alumina molten metal requires approximately four hours for natural crystallization. Using existing waste heat recovery devices, the molten metal cools too quickly during the heat recovery process, leading to excessively rapid crystallization and difficulty in separating internal impurities. Furthermore, it results in excessively small crystals that fail to meet actual performance requirements. If crystallization performance is considered, performing waste heat recovery after four hours would result in significant heat loss during the initial cooling process, leading to energy waste. In addition, research shows that existing waste heat recovery devices produce low-grade products with limited usable output. For example, in existing ladles with built-in water cooling layers, the circulating water outlet temperature during waste heat recovery is only around 353K, suitable only for domestic hot water use, resulting in low product heat utilization. Summary of the Invention

[0005] To overcome the above-mentioned technical defects, the present invention provides a waste heat recovery device and method for brown fused alumina ladle, which can solve the technical problem that existing brown fused alumina waste heat recovery devices are difficult to efficiently recover waste heat from ladle while ensuring the good performance of brown fused alumina.

[0006] To achieve the above objectives, the present invention employs the following technical content:

[0007] A waste heat recovery device for brown fused alumina cladding includes a heat insulation barrier;

[0008] The heat insulation barrier includes a steel outer shell, a radiating layer, and a heat insulation layer arranged from the outside in;

[0009] The top of the heat insulation barrier is provided with a cover plate, and the heat insulation barrier and the cover plate form a closed cavity. During waste heat recovery, the receiving package is placed in the closed cavity.

[0010] The cover plate includes a first stainless steel layer, an intermediate layer, and a second stainless steel layer arranged from top to bottom;

[0011] The inner wall of the cover plate is provided with a heat exchange component with adjustable flow rate.

[0012] Furthermore, a shuttle vehicle is connected to the bottom of the heat insulation barrier, and the shuttle vehicle is set on a ground track.

[0013] Furthermore, the shuttle vehicle is equipped with grooves for placing heat insulation barriers and receiving packages;

[0014] An insulation layer is provided on the protruding part between the two grooves, and the insulation layer is made of aluminum silicate fiber blanket.

[0015] Furthermore, the heat exchange component with adjustable flow rate adopts a cooling pipe.

[0016] Furthermore, the cooling pipe adopts a serpentine structure and is fixed to the inner wall of the cover plate by a support ring.

[0017] Furthermore, the top of the receiving package is covered with a receiving cap.

[0018] Furthermore, the receiving cover includes a connected stainless steel outer shell and a refractory material layer; the stainless steel outer shell is provided with a receiving cover lifting lug.

[0019] Furthermore, the heat insulation barrier adopts a hexagonal cubic structure.

[0020] Furthermore, the steel outer shell and the first stainless steel layer are both made of Q345 stainless steel; the radiating layer and the second stainless steel layer are both made of 316L stainless steel; and the insulation layer and the intermediate layer are both made of aluminum silicate fiber blanket.

[0021] A waste heat recovery method based on the above-mentioned waste heat recovery device for brown fused alumina receiving ladle includes:

[0022] Place the package inside the heat insulation barrier;

[0023] Pour the molten brown fused alumina into the receiving container;

[0024] The cover plate with the adjustable flow rate heat exchange component is placed on the heat insulation barrier, so that the inlet is completely in the closed cavity.

[0025] The flow rate of the heat exchange components is adjusted to recover the waste heat stored in the waste heat recovery device.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] This invention provides a waste heat recovery device for brown fused alumina ladle. The device includes a heat insulation barrier and a cover plate, which together form a closed cavity for placing the ladle. An adjustable-flow-rate heat exchange component is installed on the inner wall of the cover plate, enabling effective control of the heat exchange rate. During waste heat recovery, the ladle is placed in the heat insulation barrier, and molten brown fused alumina is poured into it. The cover plate with the adjustable-flow-rate heat exchange component is placed on the heat insulation barrier, ensuring the ladle is completely within the closed cavity. The flow rate of the heat exchange component is adjusted. Initially, the heat exchange medium is introduced at a low flow rate, which is gradually increased. After a period of time, a stable operating flow rate is maintained to effectively recover the waste heat stored in the device. This device can maximize the recovery of heat dissipated during cooling while ensuring the crystallization performance of brown fused alumina, thus achieving efficient energy utilization. The device has a simple structure, is easy to implement and maintain, and has good application value.

[0028] Preferably, in this invention, by arranging suitable ground rails for the shuttle car to move, the brown fused alumina package can be conveniently moved to a suitable cooling location. The cooperation between the shuttle car and the ground rails improves the convenience of the device.

[0029] More preferably, in this invention, the shuttle vehicle is provided with a groove for placing a heat insulation barrier and a groove for placing a receiving package. This design facilitates positioning during assembly. In addition, a heat insulation layer is provided on the protruding part between the grooves, which effectively prevents the loss of residual heat from the bottom of the receiving package and ensures the waste heat recovery and utilization rate.

[0030] Preferably, in this invention, the heat exchange component with adjustable flow rate adopts a cooling pipe, and the cooling pipe adopts a serpentine structure. This can increase the flow time of cooling water and the heat exchange area within a limited space, thereby ensuring that the cooling water can fully exchange heat, taking into account the ease of pipe layout, economy and heat recovery effect.

[0031] Preferably, in this invention, a receiving cover is used to cover the top of the receiving package. The presence of the receiving cover can, on the one hand, reduce the heat exchange between the molten metal at the top and the air, thus reducing the loss of a large amount of heat; on the other hand, compared with setting circulating water cooling inside or on top of the receiving package, it can prevent the high-temperature molten brown corundum from overflowing or leaking during transportation and heat exchange, and avoid explosions caused by contact with water, which could result in incalculable hazards, thereby improving the safety of transportation and heat exchange processes.

[0032] More preferably, in this invention, the receiving cover adopts a double-layer structure of stainless steel shell and refractory material layer. Compared with the prior art and natural cooling, it can maximize the heat recovery effect of the waste heat recovery device without affecting the crystallization performance of brown fused alumina.

[0033] Preferably, in this invention, the heat insulation barrier adopts a hexagonal cube structure. Under the same vertical spacing, it is superior to the conventionally used square cube and triangular cube in terms of material usage and enclosed cavity volume. The use of a hexagonal cube effectively ensures the heat exchange effect and facilitates actual production and deployment. It can maximize the heat exchange effect in the enclosed cavity while optimizing cost and production.

[0034] Preferably, in this invention, both the heat insulation barrier and the cover plate adopt a three-layer structure with a heat insulation layer to reduce heat exchange with the outside world, thereby maximizing the reduction of heat loss; the overall compact closed cavity structure also makes full use of radiative heat exchange, and the compact closed cavity structure enhances radiative heat exchange between surfaces and increases the temperature of heat exchange products; due to the reduction of the outer wall surface area, the heat exchange loss with the outside world is also relatively low.

[0035] The present invention also provides a waste heat recovery method for brown fused alumina receiving packages. Based on the above-mentioned waste heat recovery device, this method places the receiving package in a closed cavity surrounded by a heat insulation barrier and a cover plate, and adjusts the flow rate of the heat exchange components to achieve control of the heat exchange rate from slow to fast. Under the premise of ensuring the good performance of brown fused alumina products, the method recovers the heat dissipated during the cooling process to the maximum extent, thereby achieving efficient energy utilization. Attached Figure Description

[0036] Figure 1 A schematic diagram of a waste heat recovery device for brown fused alumina receiving packages provided in an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of the structure of a waste heat recovery device in the waste heat recovery working state provided in an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of the shuttle vehicle structure of the waste heat recovery device provided in an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of the heat insulation barrier structure of the waste heat recovery device provided in an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of the cover plate and cooling pipe structure of the waste heat recovery device provided in an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of the receiving cover structure of the waste heat recovery device provided in an embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram illustrating the solidification rate of molten metal under different capping materials provided in an embodiment of the present invention.

[0043] Figure 8 This is a schematic diagram of the temperature of the top cover plate under different receiving cover materials provided in an embodiment of the present invention;

[0044] Figure 9 A schematic diagram of the solidification rate and outer wall temperature of brown fused alumina melt under natural cooling conditions, provided in an embodiment of the present invention.

[0045] Figure 10 This is a schematic diagram illustrating the heat exchange effect within the device under different sealing cavity structures provided in the embodiments of the present invention;

[0046] Figure 11 This is a schematic diagram of the outlet temperature when the circulating water flow rate is 1 m / s, provided in an embodiment of the present invention.

[0047] Figure 12 This is a schematic diagram showing the temperature distribution at different heights within the device provided in an embodiment of the present invention;

[0048] Figure 13 This is a schematic diagram illustrating the difference between the solidification rate of the melt under circulating water speed of 1 m / s and the natural cooling condition in an embodiment of the present invention.

[0049] Figure 14 A schematic diagram of the outlet temperature when the circulating water flow rate is 0.5 m / s, provided for an embodiment of the present invention.

[0050] Figure label:

[0051] 1. Shuttle vehicle; 101. Insulation layer; 102. Shuttle body; 103. Rollers; 2. Ground rail; 3. Package receiving; 4. Package receiving cover; 401. Package receiving cover lifting lug; 402. Stainless steel outer shell; 403. Refractory material layer; 5. Heat insulation barrier; 501. Steel outer shell; 502. Radiation layer; 503. Thermal insulation layer; 6. Cooling pipe; 601. Cooling water inlet pipe; 602. Cooling water outlet pipe; 7. Cover plate; 701. Cover plate lifting lug; 702. First stainless steel layer; 703. Intermediate layer; 704. Second stainless steel layer; 705. Support ring. Detailed Implementation

[0052] To make the technical problems solved by the present invention, the technical solutions, and the beneficial effects clearer, the following specific embodiments provide a further detailed description of the present invention. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0055] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0056] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0057] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0058] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0059] Example

[0060] The present invention provides a waste heat recovery device for brown fused alumina ladle, including a transfer car 1 for transporting brown fused alumina ladle 3 and a cover plate 7. The transfer car 1 has grooves for installing heat insulation barriers 5 and placing tilting furnace ladle. The protruding part between the grooves is provided with a heat insulation layer 101. The cover plate 7 has multiple support rings 705 on its inner wall surface to fix the serpentine cooling pipe 6.

[0061] The insulation layer 101 on the shuttle car 1 is made of 20mm thick aluminum silicate fiber blanket, and four rollers 103 are symmetrically installed under the shuttle car to facilitate the movement of the waste heat recovery device on the ground track 2.

[0062] The transfer car 1 carries the ladle 3 for the tilting furnace. The ladle cover 4 is designed according to the specifications of the ladle 3 to be carried. The ladle cover 4 has a double-layer structure. From the inside to the outside, it is a refractory material layer 403 of silicon carbide with a thickness of 100mm and a stainless steel shell 402 of 316L stainless steel with a thickness of 20mm. Two symmetrical ladle cover lifting lugs 401 are welded to the stainless steel shell 402.

[0063] The heat insulation barrier 5 consists of six equal-sized independent panels, which are equilateral hexagons in shape. The independent panels are connected by welding. Each independent panel has a three-layer structure: a radiant layer 502 made of 316L stainless steel with a thickness of 10mm, an insulation layer 503 made of aluminum silicate fiber blanket with a thickness of 60mm, and a steel outer shell 501 made of Q345 stainless steel with a thickness of 16mm.

[0064] The cover plate 7 is made of a 20mm thick 316L stainless steel layer 702, a 30mm thick aluminum silicate fiber blanket intermediate layer 703, and a 10mm thick Q345 stainless steel layer 704. A certain number of support rings 705 are welded to the inner wall of the cover plate 7. The support rings 705 are made of 316L stainless steel and are used to fix the serpentine cooling pipe 6. The cooling pipe 6 is made of copper and has a cooling water inlet pipe 601 and a cooling water outlet pipe 602 at its two ends.

[0065] The present invention will be further explained and described below with reference to the accompanying drawings and embodiments:

[0066] like Figure 1 As shown, this embodiment provides a waste heat recovery device for brown fused alumina receiving bags, including a shuttle car 1, a heat insulation barrier 5, a receiving bag 3, a receiving bag cover 4, a cover plate 7, and a cooling pipe 6.

[0067] like Figure 2 As shown, the waste heat recovery device is in the waste heat recovery working state. The heat insulation barrier 5, the cover plate 7, and the bottom shuttle car 1 form a closed cavity, in which the receiving package 3 is located and covered by the receiving package cover 4. Cooling pipes 6 are installed on the inner wall of the cover plate 7 for heat exchange, thereby completing the waste heat recovery.

[0068] like Figure 3 As shown, in this embodiment, the shuttle vehicle 1 includes a shuttle vehicle body 102 and a plurality of rollers 103 disposed at its bottom for moving on the ground track 2; the top surface of the shuttle vehicle body is provided with a groove for placing the heat insulation barrier 5 and the receiving bag 3, and the protruding part between the grooves is provided with a heat insulation layer 101 for heat preservation of the bottom heat.

[0069] like Figure 4 As shown, the heat insulation barrier 5 is an equilateral hexagon, with independent panels connected by welding. Each panel has a three-layer structure: a radiant layer 502 made of 316L stainless steel with a thickness of 10mm, an insulation layer 503 made of aluminum silicate fiber blanket with a thickness of 60mm, and a steel outer shell 501 made of Q345 stainless steel with a thickness of 16mm, ensuring the heat insulation effect of the heat insulation barrier 5. The heat insulation barrier adopts a hexagonal cubic structure, which, with the same vertical spacing, is superior to conventionally used square or triangular cubic structures in terms of material usage and enclosed cavity volume. The use of a hexagonal cubic structure effectively guarantees the heat exchange effect and facilitates actual production and deployment, maximizing the heat exchange effect within the sealed cavity while optimizing costs and production.

[0070] like Figure 5As shown, the cover plate 7, from the inside out, consists of a 20mm thick 316L stainless steel layer 702, a 30mm thick aluminum silicate fiber blanket intermediate layer 703, and a 10mm thick Q345 stainless steel layer 704. A number of support rings 705, also made of 316L stainless steel, are welded to the inner wall of the cover plate 7. Lifting lugs 701 are welded to the stainless steel layer 702 for easy lifting. The support rings 705 are used to fix the serpentine cooling pipe 6, which is made of copper. Its two ends are a cooling water inlet pipe 601 and a cooling water outlet pipe 602, respectively. The serpentine pipe design increases the cooling water flow time and heat exchange area within a limited space, ensuring sufficient heat exchange and balancing the ease of pipe layout, economy, and heat recovery effect.

[0071] like Figure 6 As shown, the ladle cover 4 has a double-layer structure. From the inside out, it consists of a 100mm thick silicon carbide refractory material layer 403 and a 20mm thick 316L stainless steel outer shell 402. Two symmetrical ladle cover lifting lugs 401 are welded to the stainless steel outer shell 402 to facilitate lifting the ladle cover 4. The presence of the ladle cover reduces heat exchange between the molten metal at the top and the air, preventing significant heat loss. Furthermore, compared to installing circulating water cooling inside or at the top of the ladle, it avoids the risk of high-temperature molten brown corundum overflowing or leaking during transport and heat exchange, which could lead to an explosion upon contact with water and cause incalculable hazards, thus improving safety during transportation and heat exchange.

[0072] This embodiment provides a waste heat recovery device for brown fused alumina ladle, and the specific working method is as follows:

[0073] For use in a capacity of 6m 3Taking the waste heat recovery device for receiving molten brown fused alumina in a ladle, used for heating and domestic water supply as an example, firstly, according to the actual situation of different factory buildings, a ground rail 2 is installed on the ground to facilitate the movement of the shuttle car 1 carrying the ladle 3 of the tilting furnace; then, before the tilting furnace smelting is completed, the shuttle car 1 carrying the empty ladle is moved to the front of the tilting furnace, and the ladle cover 4 is lifted by the ladle cover lifting lug 401, waiting for the molten brown fused alumina to be poured; after the brown fused alumina in the tilting furnace is smelted, the molten liquid is poured into the ladle 3. After the pouring is completed, the ladle cover 4 is placed on the ladle 3 again by the ladle cover lifting lug 401, and then the top cover plate 7 with the serpentine cooling pipe 6 fixed is placed on the heat insulation barrier 5 by the lifting device, completing the overall sealing of the waste heat recovery device. Then, move the shuttle car 1 to the cooling area, connect the cooling water inlet pipe 601 to the water pump, connect the water pump to the cold water tank, and connect the cooling water outlet pipe 602 to the water storage tank. After all connections are completed, first introduce cooling water at a low flow rate, and gradually increase the flow rate from 0 to 1 m / s over about 8 minutes. Then, operate steadily at a flow rate of 1 m / s to recover the waste heat stored in the device. The recovered high-temperature water flows into the water storage tank for domestic water and heating.

[0074] After the heat exchange process is completed, the water pipe connection is disconnected. The top cover 7, the receiving ladle cover 4, and the receiving ladle 3 are then lifted sequentially using a lifting device. A new receiving ladle is then placed in front of the tilting furnace, awaiting the next batch of molten liquid to be poured. This cycle is repeated to fully utilize the waste heat recovery device. This waste heat recovery device can also obtain high-temperature steam for refrigeration or power generation by adjusting the flow rate or increasing the inlet temperature of the circulating water.

[0075] The effects of this embodiment will be further explained below with reference to experimental data:

[0076] This embodiment provides a waste heat recovery device for brown fused alumina receiving ladle, which has the following beneficial effects:

[0077] 1. In this embodiment, the brown fused alumina package can be conveniently moved to a suitable cooling location by arranging appropriate ground tracks for the shuttle vehicle to move.

[0078] 2. In this embodiment, after the molten brown fused alumina is poured into the receiving ladle, the ladle is sealed by a lifting device. The presence of the ladle cover can reduce heat exchange between the molten liquid at the top and the air, thus reducing the loss of a large amount of heat. On the other hand, compared with setting circulating water cooling inside or at the top of the ladle, it can prevent the high-temperature molten brown fused alumina from overflowing or leaking during transportation and heat exchange, and avoid explosions caused by contact with water, which could result in incalculable hazards, thereby improving the safety of transportation and heat exchange processes.

[0079] 3. In this embodiment, the selection of different capping materials can control the rate of heat release and solidification of molten brown corundum within the device. Numerical simulations are used to compare the specific effects, as follows: Figure 7 and Figure 8 As shown, compared to natural cooling, the presence of the ladle cover can slow down the solidification rate of the molten metal, thus appropriately mitigating the impact of the introduction of cooling water on the solidification rate. When the ladle cover contains a mullite insulation layer, it can maximize the slowing down of the solidification rate, but it also inhibits the loss of heat from the molten metal to some extent, resulting in a lower grade of waste heat recovery products. A single-layer 316L stainless steel ladle cover may experience a high peak temperature, leading to material melting. In summary, a double-layer ladle cover structure is selected. Compared with existing technologies and natural cooling, it can maximize the heat recovery effect of the waste heat recovery device without affecting the crystallization performance of brown fused alumina.

[0080] 4. In this embodiment, after the cover is closed, the cover plate with the fixed serpentine cooling pipe is installed on top of the waste heat recovery device using a lifting device, thereby sealing the inner cavity of the waste heat recovery device. Figure 9 As shown, the outer wall temperature of the receiving package can reach up to 750K during the natural cooling process. It undergoes a large amount of radiation and convection heat exchange with the air, resulting in a significant loss of heat. In this embodiment, since an aluminum silicate fiber felt insulation layer is provided between the cover plate and the heat insulation barrier, compared with setting heat exchange paths inside or on top of the receiving package, it can reduce the heat loss caused by heat exchange between the wall temperature and the external air during transportation and heat exchange, thereby maximizing the recovery of heat released by the molten brown corundum.

[0081] 5. In this embodiment, the heat insulation barrier adopts a hexagonal cube structure, which, with the same vertical spacing, is superior to conventionally used square or triangular cubes in terms of material usage and enclosed cavity volume, and is similar to a cylindrical structure. Figure 10 As shown, the hexagonal cube and cylindrical structures exhibit the best heat exchange performance. Compared to the cylindrical structure, the hexagonal cube structure is simpler in terms of actual production and cooling water pipe layout. Therefore, considering all factors, the hexagonal cube structure is chosen because it maximizes the heat exchange effect within the sealed cavity while optimizing costs and production compared to other conventional structures.

[0082] 6. In this embodiment, an insulation barrier with a thermal insulation layer and a cover plate are used to reduce heat exchange with the outside environment, thereby maximizing heat loss. The resulting compact, enclosed cavity structure also makes full use of radiative heat transfer. Existing technologies for waste heat recovery of fused magnesium employ waste heat recovery chambers that can accommodate three fused magnesium lumps, with circulating water flowing at a rate of 1 m / s. With three internal heat sources at a temperature of 2800 K, the temperature of the waste heat recovery product is approximately 353 K. In contrast, the compact, enclosed cavity structure used in this embodiment enhances radiative heat transfer between surfaces, increasing the temperature of the heat transfer product; due to the reduced outer wall area, heat exchange losses with the outside environment are also relatively low. Figure 11 As shown, using the same circulating water flow rate, in this embodiment, the peak temperature of the heat exchange products can reach about 396K, further improving the temperature and grade of the heat exchange products.

[0083] 7. In this embodiment, numerical calculations revealed that, consistent with existing waste heat recovery methods, during the initial heat exchange phase, the entire device is in a heated state, and much of the released heat is absorbed by the internal structure, resulting in low-temperature hot water that cannot be directly utilized. When circulating water flows at a rate of 1 m / s, the outlet water temperature only reaches above 353 K after approximately 30 minutes. Introducing circulating water after 30 minutes would lead to excessively high internal structural temperatures, posing a significant safety hazard. If the structural heat resistance temperature allows, introducing circulating water at a low rate before 30 minutes, gradually increasing the rate to 1 m / s, allows the temperature to reach 353 K in approximately 8 minutes, further improving heat utilization efficiency.

[0084] 8. In this embodiment, the cooling pipes are arranged in a serpentine pattern. This increases the cooling water flow time and heat exchange area within a limited space, thereby ensuring sufficient heat exchange. Based on numerical calculations, such as... Figure 12 As shown, the heat gradually rises from bottom to top inside the square cavity. Taking into account the ease of pipe layout, economy, and heat recovery effect, a serpentine cooling pipe is arranged at the cover plate.

[0085] 9. In this embodiment, the presence of the enclosed cavity and the cap will inhibit the overall crystallization rate of the brown fused alumina melt to a certain extent, while the introduction of cooling water will accelerate the crystallization rate to some extent. Simulation calculations show that... Figure 13 As shown, due to the presence of the cap, the overall solidification rate of the two is almost the same after they are combined, compared with natural cooling. The difference in solidification rate is within 0.5%, so the performance of brown fused alumina products can be guaranteed while recovering waste heat.

[0086] 10. In this embodiment, as Figure 14 As shown, a 6m package 3Taking the cooling process of molten brown corundum as an example, by reducing the circulating water flow rate, such as introducing circulating water at a flow rate of 0.5 m / s, high-temperature steam above 400 K can be obtained for nearly 15 hours. Theoretical calculations show that the waste heat recovery efficiency can reach 58.9%, while the waste heat recovery efficiency of existing technologies designed for fused magnesia waste heat recovery chambers is only around 30%. (Summary) Figure 11 and Figure 14 Different circulating water flow rates can yield waste heat products at different temperatures, which can be used for domestic hot water, heating, cooling, and power generation, depending on the season and scenario.

[0087] 11. In this embodiment, when the temperature of the molten brown fused alumina is low in the later stage of the heat exchange process, circulating heat exchange or multiple ladles connected in series can be adopted to recover as much useful waste heat as possible. Calculations show that when the brown fused alumina solidifies to an outer wall temperature of less than 900K, the overall heat exchange effect is poor. At this point, the top cover, ladle cover, and ladle can be removed sequentially using a lifting device to pour out the solid brown fused alumina blocks for subsequent crushing and screening processes.

[0088] 12. In this embodiment, after the cooled ladle is removed, a new ladle can be hoisted into the waste heat recovery device and transported to the three-phase electric arc furnace for receiving new molten metal, and the above waste heat recovery process can be repeated. Compared with existing waste heat recovery devices, this embodiment does not change the ladle cover structure, and its overall operation is simpler and it is easy to reuse in a short time.

[0089] 13. In this embodiment, the waste heat recovery device not only recovers waste heat but also accelerates the solidification rate of the brown fused alumina melt. Taking a circulating water flow rate of 1 m / s as an example, compared to the 30-hour solidification time of natural cooling, calculations show that the solidification time in the waste heat recovery device is only about 24 hours. With multiple units connected in series, the circulating water flow rate can be further increased, further reducing the cooling time of the brown fused alumina while ensuring the outlet temperature of the heat exchange products.

[0090] In summary, the present invention provides a waste heat recovery device and method for brown fused alumina ladle, which has the following advantages compared with existing waste heat recovery devices:

[0091] This waste heat recovery device includes a heat insulation barrier and a cover plate, which together form a closed cavity for placing the receiving package. An adjustable-flow-rate heat exchange component is installed on the inner wall of the cover plate, enabling effective control of the heat exchange rate. During waste heat recovery, the receiving package is placed in the heat insulation barrier, and molten brown fused alumina is poured into it. The cover plate, with the adjustable-flow-rate heat exchange component fixed on it, is then placed on the heat insulation barrier, ensuring the receiving package is completely within the closed cavity. The flow rate of the heat exchange component is adjusted. Initially, the heat exchange medium is introduced at a low flow rate, which is gradually increased. After a period of time, a stable operating flow rate is maintained to effectively recover the waste heat stored within the device. This device can maximize the recovery of heat dissipated during cooling while ensuring the crystallization performance of brown fused alumina, thus achieving efficient energy utilization. The device has a simple structure, is easy to implement and maintain, and has good application value.

[0092] The above embodiments are merely one of the implementation methods for achieving the technical solution of the present invention. The scope of protection claimed by the present invention is not limited to this embodiment, but also includes any variations, substitutions and other implementation methods that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention.

Claims

1. A waste heat recovery device for brown fused alumina receiving ladle, characterized in that, Including thermal insulation barriers (5); The heat insulation barrier (5) includes a steel outer shell (501), a radiation layer (502), and a heat insulation layer (503) arranged from the outside to the inside; The top of the heat insulation barrier (5) is provided with a cover plate (7), and the heat insulation barrier (5) and the cover plate (7) form a closed cavity. When recovering waste heat, the receiving package (3) is placed in the closed cavity. The cover plate (7) includes a first stainless steel layer (702), an intermediate layer (703), and a second stainless steel layer (704) arranged from top to bottom; The inner wall of the cover plate (7) is provided with a heat exchange component with adjustable flow rate.

2. The waste heat recovery device for brown fused alumina receiving ladle according to claim 1, characterized in that, The bottom of the heat insulation barrier (5) is connected to a shuttle car (1), which is set on the ground track (2).

3. A waste heat recovery device for brown fused alumina receiving ladle according to claim 2, characterized in that, The shuttle vehicle (1) is provided with grooves for placing the heat insulation barrier (5) and the receiving bag (3); The protruding portion between the two grooves is provided with an insulation layer (101), which is made of aluminum silicate fiber blanket.

4. A waste heat recovery device for brown fused alumina receiving ladle according to claim 1, characterized in that, The adjustable flow rate heat exchange component uses a cooling pipe (6).

5. A waste heat recovery device for brown fused alumina receiving ladle according to claim 4, characterized in that, The cooling pipe (6) adopts a serpentine structure and is fixed to the inner wall of the cover plate (7) by a support ring (705).

6. A waste heat recovery device for brown fused alumina receiving ladle according to claim 1, characterized in that, The top of the receiving package (3) is covered with a receiving package cover (4).

7. A waste heat recovery device for brown fused alumina receiving ladle according to claim 6, characterized in that, The receiving cover (4) includes a connected stainless steel shell (402) and a refractory material layer (403); the stainless steel shell (402) is provided with a receiving cover lifting lug (401).

8. A waste heat recovery device for brown fused alumina receiving ladle according to claim 1, characterized in that, The heat insulation barrier (5) adopts a hexagonal cubic structure.

9. A waste heat recovery device for brown fused alumina receiving ladle according to claim 1, characterized in that, The steel outer shell (501) and the first stainless steel layer (702) are both made of Q345 stainless steel; the radiation layer (502) and the second stainless steel layer (704) are both made of 316L stainless steel; the insulation layer (503) and the intermediate layer (703) are both made of aluminum silicate fiber blanket.

10. A waste heat recovery method based on the waste heat recovery device for brown fused alumina receiving bags according to any one of claims 1-9, characterized in that, include: Place the receiving package (3) in the heat insulation barrier (5); Pour the molten brown corundum into the receiving bag (3); The cover plate (7) with the adjustable flow rate heat exchange component is placed on the heat insulation barrier (5) so that the receiving package (3) is completely in the closed cavity; The flow rate of the heat exchange components is adjusted to recover the waste heat stored in the waste heat recovery device.

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