High-temperature steel slag bulk heat recovery device

Abstract

The utility model discloses a high temperature steel slag bulk specific heat recovery device, solve the process drawback of existing vertical type filler bed. Steel slag stockpile in the furnace chamber is under the control of the discharging system and drops at uniform speed, and the distributor and the feed pipe are always in the full bin state, and through the control of the feed speed and the discharging speed, the steel slag stockpile in the furnace chamber is kept at the constant thickness, the on-line material level control system is according to the upper and lower limit of steel slag stockpile height, combines the temperature sensor detection data at high temperature heat exchange section, medium temperature heat exchange section and low temperature cooling section in the furnace chamber, and the vibration discharging machine and the loading trolley in the feed system and the discharging system are linked and feedback, ensure the uniform subsidence of steel slag same temperature material layer, ensure the balance of temperature field and wind field. This technology improves steel slag material distribution segregation, promotes steel slag material to flow as " whole flow " and realizes uniform air distribution, promotes the collaborative operation of steel slag and cold air, improves the gas solid heat exchange efficiency.

Description

Technical Field

[0001] This utility model relates to the technical field of sensible heat recovery equipment for high-temperature steel slag bulk materials. Background Technology

[0002] In existing technologies, processes for recovering sensible heat from high-temperature steel slag bulk materials, in the air-cooling route, include two main categories: the hot air extraction process using an annular cooler and the direct hot air extraction process using a packed bed.

[0003] The annular cooler heat extraction process is based on the steel slag cooling process. It can recover the sensible heat of the hot steel slag material in the high-temperature and medium-temperature heat exchange sections. However, when the temperature of the hot steel slag material is below 300 degrees Celsius, the extracted hot air is generally no higher than 150 degrees Celsius, making it difficult to utilize effectively and resulting in some energy waste. In addition, the annular cooler is generally directly connected to the sintering machine, cooling a large amount of steel slag material. The material layer needs to be stable, with a thickness of no less than 1 meter, to ensure stable flue gas temperature.

[0004] In recent years, some companies have tried heat extraction technology for high-temperature bulk steel slag. However, because the incoming steel slag is not as stable as that of a sintering machine, the steel slag layer on the annular cooler is uneven or discontinuous, resulting in unstable hot air in the high-temperature heat exchange section of the annular cooler. Sudden drops in flue gas temperature are often caused by air leakage, which cannot meet the requirements for continuous and stable output of temperature and hot air flow. In addition, the inability to recover the medium and low temperature cooling section of the annular cooler (the temperature range of steel slag below 300℃) also results in a low heat recovery ratio. Therefore, heat extraction from the annular cooler is difficult to meet the needs of special incoming steel slag processes.

[0005] The vertical heat exchanger furnace's direct hot air extraction process draws on dry quenching and vertical furnace technologies. Employing a packed bed and counter-current airflow heat exchange technology, this process is increasingly being explored by companies attempting to replace annular coolers for heat extraction during the cooling of steel slag and pellets. The aim is to increase heat recovery in the low-temperature cooling section and reduce energy consumption in the heat extraction process itself. Currently, domestic companies are continuously improving and testing this technology, accumulating substantial experience data and providing engineering practice for heat extraction from high-temperature bulk material vertical furnaces.

[0006] The core issues that need to be addressed in the direct hot air extraction technology of the packed bed are: 1. Ensuring the contact time between the air and the hot steel slag material to ensure the stability of the flue gas temperature and flow rate after heat exchange; 2. Ensuring the smooth descent of the steel slag material in the vertical furnace, ideally achieving a uniform descent of the material layer at the same temperature to prevent uneven heat exchange caused by steel slag material segregation, which in turn affects the stability of the produced hot air.

[0007] In addition, the current filling bed adopts the free-fall supply method of steel slag, that is, the steel slag is filled into the furnace by falling. In this process, the steel slag pile has a significant dispersed particle distribution characteristic, which reduces the uniformity of the porosity distribution of the material layer. That is, the steel slag particles in the center of the pile are small and the steel slag particles at the edge are large, and it has a normal distribution characteristic. This makes the wind resistance at the edge of the pile low and the wind resistance in the center of the pile high, thus making the air cooling effect not prominent, further worsening the distribution of cold air in the furnace, and reducing the gas-solid heat exchange efficiency. Utility Model Content

[0008] To address the shortcomings of existing technologies, this utility model provides a high-temperature steel slag bulk sensible heat recovery device. By improving the structure of the vertical heat exchanger furnace, a new sensible heat recovery equipment and process are formed, solving the process drawbacks of the existing vertical packed bed.

[0009] The technical solution adopted by this utility model to solve its technical problem is as follows: A high-temperature steel slag bulk sensible heat recovery device includes a vertical shaft furnace constructed of refractory materials. Inside the furnace, the furnace cavity consists of, from top to bottom, a feeding and hot air collection section, a high-temperature heat exchange section, a medium-temperature heat exchange section, and a low-temperature cooling section. An equipment platform is located at the top of the furnace, and a discharge device is located at the bottom. The device is characterized by having a feed distributor mechanically connected to the feed pipe in the feeding and hot air collection section. Driven by a winch installed on the equipment platform, the feed distributor is height-adjustable, and its lower outlet is inserted into the steel slag. The top of the slag pile is filled with material, and the feeder and feed pipe are full. An air-collecting ring cavity is installed on the furnace body in this section. Multiple windows are provided on the inclined baffles of the air-collecting ring cavity, through which hot air from the top of the furnace cavity is collected. The hot air is then collected by a hot air pipe and discharged to a cyclone dust collector. The hot air temperature is approximately 300℃-500℃. The temperature of the steel slag material in the upper part of the furnace cavity is approximately 650℃-850℃, and it is further controlled by a high-temperature heat exchange section, a medium-temperature heat exchange section, and a low-temperature cooling section. Continuous air cooling and heat exchange lower the discharge system temperature to below 180℃; cold air at 20-35℃ is blown in from the bottom of the furnace and blown in a reverse direction from bottom to top, passing through layers of steel slag at different temperatures before finally being discharged from the top of the furnace. Simultaneously, the cold air is heated to over 320℃ by the hot steel slag, forming hot air; an air distributor is installed inside the low-temperature cooling section, connected to an external blower; the steel slag pile in the furnace cavity descends at a uniform speed under the control of the discharge system, and the distributor and feed pipe are always kept full, adjusting according to different particle sizes. The porosity of the steel slag particles is adjusted, and the height of the material is controlled. By maintaining a consistent feeding and discharging speed, the steel slag pile in the furnace cavity is kept at a constant thickness. The online material level control system uses the upper and lower limits of the steel slag pile height, combined with temperature sensor data from the high-temperature heat exchange section, medium-temperature heat exchange section, and low-temperature cooling section in the furnace cavity, to link and provide feedback to the vibrating discharge machine and the feeding trolley in the feeding and discharging systems. This ensures uniform settling of the steel slag layer at the same temperature and maintains a balance in the temperature and wind fields.

[0010] Furthermore, the fabric distributor consists of multiple telescopic joints nested together and a conical cover, with safety ropes installed between adjacent telescopic joints and a cover at the bottom of the telescopic joint. It also has at least two wire rope drive mechanisms, each consisting of a wire rope and an electric winch. The electric winch is mounted on the equipment platform and is used to adjust the height of the telescopic joints.

[0011] Furthermore, the edge of the cover is equipped with a rolling component, through which the material distributor mechanically engages with the inner wall of the furnace cavity, and is able to bear part of the horizontal load, so that the material distributor is always in a centered state.

[0012] Furthermore, the space below the material distributor in the furnace cavity is filled with steel slag. The temperature of the steel slag in the upper part of the furnace is about 650°C to 850°C, while the temperature of the discharge system drops to within 180°C. The hot steel slag takes about 1 to 10 hours from entry to discharge, with an average flow rate of about 0.1 to 3 m / h.

[0013] Furthermore, a roller screen is installed to screen out steel slag blocks larger than 80mm, while hot steel slag smaller than 80mm is lifted into the vertical furnace by a feeding trolley.

[0014] Furthermore, the air distributor uses a ring-shaped arrangement to set up multiple cold air ducts, which are unevenly arranged in the height direction.

[0015] Furthermore, by setting air outlets on the cover of the aforementioned fabric distributor, the hot air outlets at the top become more uniform and consistent, which is beneficial for uniform cooling.

[0016] Furthermore, the fabric feeder is an electrically driven rotary fabric feeder. Furthermore, the inner wall of the furnace cavity is fitted with refractory and smooth ceramic.

[0017] The beneficial effects of this utility model are: This technology improves the distribution and segregation of steel slag, promotes the "overall flow" of steel slag, and achieves uniform air distribution, thereby promoting the coordinated operation of steel slag and cold air and improving gas-solid heat exchange efficiency. The technical effects of this technology will be further elaborated in the specific implementation details. Attached Figure Description

[0018] Figure 1 These are the drawings for the steel slag processing production line.

[0019] Figure 2 This is a display of the vertical structure of a vertical heat exchanger.

[0020] Figure 3 for Figure 2 Sectional view A-A.

[0021] Figure 4 for Figure 2 Foundation plan at a height of M2 meters.

[0022] Figure 5 A vertical cross-sectional view of the hot air collection pipes at the top of the furnace.

[0023] Figure 6 A vertical cross-sectional view of the hot air collection pipes at the top of the furnace.

[0024] Figure 7 This is a vertical view of the fabric feeder, showing the fabric application at a high point.

[0025] Figure 8This is a vertical view of the fabric feeder, showing the fabric application at a high point.

[0026] Figure 9 The structure of the fabric feeder is shown, illustrating implementation method one.

[0027] Figure 10 for Figure 9 The corresponding 3D image.

[0028] Figure 11 The structure of the fabric feeder is shown, illustrating implementation method two.

[0029] Figure 12 Figure 2 Plan view at height M5.

[0030] Figure 13 Figure 2 Plan view at mid-height M4.

[0031] Figure 14 Figure 2 Plan view at M7 (medium altitude).

[0032] Figure 15 Figure 2 Layout diagram of the embedded steel plate at the medium height M0.

[0033] Figure 16 Figure 2 Layout diagram of the suspension bracket for the vibratory discharge machine at a medium height of M0.

[0034] Figure 17 Figure 2 Layout diagram of the vibrating discharge machine at the medium height M0.

[0035] Figure 18 This is the front view of the vibrating discharge machine.

[0036] Figure 19 This is a side view of the vibrating discharge machine.

[0037] Figure 20 This is a vertical sectional view of the intermediate transition buffer compartment.

[0038] Figure 21 This is a horizontal cross-sectional view of the intermediate transition buffer zone.

[0039] Figure 22 This is a schematic diagram of the installation of the vibration motor and the buffer chamber.

[0040] In the picture: 100. Vertical heat exchanger; 110. Equipment platform; 120. Roller screen; 130. Lifting winch; 140. Material distributor; 141. Expansion joint; 142. Cover; 143. Safety rope; 144. Rolling assembly; 150. Air distributor. 210. Unloading platform; 220. Loading trolley. 310. Chain conveyor; 320. Vibrating discharge machine; 330. Buffer bin. 410. Air collection chamber; 411. Window; 420. Hot air duct; 430. Cyclone dust collector. Detailed Implementation

[0041] As a high-temperature heat source, the average temperature of incoming steel slag is about 1100℃. Sometimes, there will be whole or large crusts on the surface of the slag pot and the shell of the slag pot. Occasionally, large iron blocks will sink to the bottom of the slag pot. This requires pretreatment of the molten and semi-molten steel slag to reduce the temperature of the steel slag to below 950℃ (so that it no longer sticks together) and to process the particle size to below 80mm before it enters this heat exchange equipment for heat exchange.

[0042] The steel slag is then lifted to a height by the feeding system and fed into the furnace via a drop method. The feeding speed of the steel slag is controlled by the lifting speed. This embodiment will be described in conjunction with the appendix to the instruction manual. Figure 1 To be continued Figure 22 A detailed explanation will be provided.

[0043] This heat exchange equipment is a vertical heat exchange furnace 100 that has undergone new technological upgrades. The entire furnace is constructed using refractory materials and is functionally divided into five parts along its height: from top to bottom, the feeding and hot air collection section L1, the high-temperature heat exchange section L2, the medium-temperature heat exchange section L3, the low-temperature cooling section L4, and the discharge system. The furnace body is composed of high-alumina wear-resistant bricks, lightweight insulating bricks, calcium silicate board, and an outer shell, achieving a triple effect of wear resistance, high-temperature resistance, and thermal insulation, ensuring a heat loss of no more than 5%.

[0044] At the top of the furnace body is an equipment platform 110, which is equipped with a feed inlet. The feed equipment platform 110 is equipped with a roller screen 120 and a lifting winch 130, and provides a high point for the lifting equipment. The lifting winch 130 is used to drive the height of the material distributor 140.

[0045] The vertical heat exchanger 100 is equipped with a feeding and discharging system in the space below the bottom. The discharging system is located at the bottom of the furnace body and preferably uses a chain conveyor or belt conveyor to achieve continuous slag discharge throughout the process. The discharging system includes a vibrating discharge machine 320, a buffer bin 330, and a chain conveyor 310.

[0046] Specifically, the feeding system consists of a discharge platform 210 and a loading trolley 220, while the discharge system consists of an adjustable speed chain conveyor 310, a vibrating discharge machine 320, and a transition buffer silo 330. It can achieve sealing and quantitative discharge of the steel slag pile in the furnace and work in conjunction with the feeding system to achieve a basically constant height of steel slag in the furnace.

[0047] In this embodiment, the steel slag stacking and counter-current airflow heat exchange technology in the vertical heat exchange furnace 100 is a vertical structure (which can be a cylinder or a cuboid). During normal production, the entire furnace body is filled with steel slag, and the material distributor 140 and the feed pipe are also filled with steel slag, thus achieving the sealing of the feed section through steel slag. Under the control of the vibrating discharge machine 320, the steel slag stockpile slowly moves downwards. The temperature of the steel slag material at the top of the furnace is approximately 650℃ to 850℃. Through continuous air cooling and heat exchange in the high-temperature heat exchange section L2, the medium-temperature heat exchange section L3, and the low-temperature cooling section L4, the temperature of the discharge system is reduced to below 180℃. Cold air at 20-35℃ is blown in from the bottom of the furnace and blown in the opposite direction from bottom to top (relative to the downward direction of the steel slag material). After passing through the steel slag layers of different temperatures, it is finally discharged from the top of the furnace. At the same time, the cold air is also heated to above 320℃-500℃ by the hot steel slag. Because the steel slag stockpile in the vertical furnace reaches about 8-20 meters, the hot air and steel slag have sufficient contact and heat exchange time, which can ensure the temperature and stability of the produced hot air. At the same time, the steel slag in the vertical furnace acts as a large heat accumulator, which can minimize the impact of the instability of the incoming steel slag on the entire hot air. In a vertical heat exchanger furnace, the effective thickness of the steel slag inside the furnace must be ensured, and the thickness of the material layer should be controllable and adjustable according to the effect of the hot air generation.

[0048] In a vertical heat exchanger furnace, it is crucial to ensure the particle size and non-agglomeration of the high-temperature steel slag material. This is because when the steel slag cools to 150°C (850°C–850°C), its molten state disappears, and it becomes a loose, non-agglomerated state. The specific heat capacity in this state is approximately 0.9 kJ / (kg•°C), and 0.648 GJ of sensible heat can be recovered from one ton of steel slag, roughly equivalent to the heat generated by the complete combustion of 22.15 kg of standard coal.

[0049] For high-temperature bulk steel slag, ensuring the correct particle size of the incoming slag is crucial to the success of the technology. Excessively large slag lumps can clog the slag discharge channels in the vertical furnace, causing uneven settling or segregation. This technology uses a high-temperature roller screen (120) to screen out slag lumps larger than 80mm, preventing them from entering the furnace. Hot slag smaller than 80mm is lifted by a feeding trolley (220) into the vertical cooling furnace, ensuring smooth system operation.

[0050] The feeding and hot air collection section has a feeding inlet and a feeding pipe that communicate with the furnace cavity, through which materials are continuously fed into the furnace cavity below. The furnace body in this section is equipped with a collecting ring cavity 410, a hot air outlet, and a hot air pipe 420. The collecting ring cavity 410 has multiple windows 411 on its inclined partition, through which hot air from the top of the furnace cavity is collected into the collecting ring cavity 410. The hot air pipe 420 collects the hot air from the collecting ring cavity 410 and discharges it to a cyclone dust collector 430. After dust removal by the cyclone dust collector 430, the clean hot air, with a temperature of approximately 300℃-500℃, is an excellent heat source. This high-temperature hot air can be used for subsequent heat recovery and reuse for production or domestic heating.

[0051] Furthermore, the air collecting ring cavity 410 is located at the top of the feeding and hot air collecting section near the top plate, surrounding the feed pipe, and achieves rapid collection and transfer of hot air through multiple windows 411 set on the inclined partition.

[0052] Furthermore, a temperature sensor is installed at the hot air duct 420 to detect the temperature of the hot air. When the temperature is low, the power of the cyclone dust collector 430 can be adjusted in a timely manner to achieve precise control of the hot air temperature. If the temperature is too low, the hot air temperature can be adjusted by adjusting the amount of steel slag fed or reducing the amount of air blower.

[0053] A distributor 140 is installed at the center of the feeding and hot air collection section. Specifically, a set of retractable and height-adjustable distributors 140 is integrated and installed at the lower end of the feeding pipe. The distributor 140 extends through the feeding and hot air collection section in the vertical direction and connects to the high-temperature heat exchange section. This allows the high-temperature steel slag to exchange heat in the high-temperature heat exchange section, the medium-temperature heat exchange section, and the low-temperature cooling section, while the cold air flows upwards in the opposite direction. This completes the heat exchange between the high-temperature steel slag and the cold air, achieving the goals of slag cooling and hot air generation.

[0054] During this process, the high-temperature steel slag in the furnace cavity descends at a controllable and uniform rate, and the distributor 140 and the feed pipe are always in a full state, meaning that the lower outlet of the distributor 140 is buried at the top of the steel slag pile. The height (length) of the distributor 140 in this structure is adjustable for steel slag of different particle sizes. By controlling the feeding and discharging speeds to maintain consistency, the thickness of the high-temperature steel slag accumulation in the furnace cavity can be controlled, ensuring a constant steel slag level and preventing air leakage by sealing the top and bottom of the slag. This achieves control over the heat exchange process and heat exchange path.

[0055] In this technology, it is necessary to ensure the uniform descent of the same material layer and the controllability and adjustability of the height of the accumulated steel slag. The heat exchange process selected in this technology is carried out in the vertical heat exchanger furnace 100, and the feeding and discharging system supporting the heat exchanger of the vertical heat exchanger furnace 100 realizes the continuous production of the entire process. The feeding system consists of a discharging platform 210 and a feeding trolley 220, and the discharging process consists of a chain conveyor + vibrating discharger 320 with adjustable quantitative discharging, which can achieve the sealing of the material column and quantitative discharging. To ensure the stability of the height of the steel slag stacking layer in the furnace, an on-line material level control system is designed. According to the upper and lower limits of the material level, the frequency of the vibrating discharger is adjusted by the discharging system, and the chain conveyor 310 is used for metering and feedback to the frequency adjustment of the vibrating discharger 320. At the same time, temperature sensors are respectively set in the high-temperature heat exchange section, medium-temperature heat exchange section, discharging system and low-temperature cooling section in the furnace cavity for on-line temperature detection, and through temperature feedback to the control system, the vibrating discharger 320 and the feeding trolley 220 are linked and feedback to ensure the uniform settlement of the steel slag with the same temperature layer, and further ensure continuous and stable heat exchange. At the same time, the temperature of the steel slag stacking in the furnace cavity is on-line detected in the high-temperature heat exchange section, medium-temperature heat exchange section and low-temperature cooling section, and temperature detection points are set in the detection system to ensure the balance of the temperature field and wind force field.

[0056] An air distributor 150 is arranged in the inner cavity of the low-temperature cooling section. The air distributor 150 is externally connected to a blower, and the blower continuously supplies air to the low-temperature cooling section.

[0057] Ensure that the air pressure of the blower can smoothly penetrate the steel slag material layer. The porosity of the steel slag is about 20%, and the bulk density is between 2.5 and 2.8.

[0058] The air distributor 150 adopts an annular layout method, arranging the lower cold air pipes in an annular shape, which coincides with the horizontal cross-section of the furnace cavity and forms several cold air pipes extending upward. The cold air pipes are unevenly arranged in the height direction, that is, some cold air pipe orifices are located at higher points, and some cold air pipe orifices are lower. This layout can reduce the interference between adjacent air ducts.

[0059] The core technology of this technology lies in the design of the vertical heat exchanger furnace 100, ensuring that the thickness of the material layer of the steel slag stacking, the temperature and particle size of the steel slag material meet the design requirements, ensuring the air pressure of the blower and the uniform descent of the material layer, and enabling the stable and efficient recovery of the sensible heat in the steel slag. Due to the powerful heat storage energy effect of the vertical heat exchanger furnace 100, the process has a lower requirement for the continuity of the incoming material, has excellent process adaptability, and can adapt to the non-continuous and stable process characteristics of the steel slag.

[0060] This vertical heat exchanger furnace 100 has a simple structure. The space below the distributor 140 in the furnace chamber is filled with steel slag. The temperature of the steel slag in the upper part of the furnace is about 850℃, while the temperature of the discharge system drops to below 180℃. The hot steel slag takes about 2 to 10 hours from entry to discharge, with an average flow velocity of about 0.1 to 5 m / h. The specific velocity is controlled by the vibrating discharge machine 320 below. It is a low-velocity, micro-impact solid flow, which can fully utilize the heat energy contained inside. The furnace wall in contact with the steel slag is entirely constructed with high-alumina wear-resistant bricks in a vertical masonry design, with a designed service life of no less than 10 years. The furnace body adopts a frame structure. When the wear-resistant bricks reach the end of their service life, they can be replaced separately without affecting the overall furnace structure.

[0061] In this technology, a counter-current gas-solid heat exchange method is adopted in the furnace cavity: cold air is introduced from the bottom of the furnace body, and high-temperature steel slag material falls from the top, with the two coming into contact in opposite directions. During this process, the speed of the steel slag material and the air velocity are controlled by temperature detection. This method extends the heat exchange path and time, significantly improves thermal efficiency, and ensures the unity of the slag cooling effect and the hot air effect. Through the lower air distributor 150 for air intake and the upper exhaust (cyclone dust collector 430), almost all of the sensible heat of the steel slag is recovered, and the waste heat recovery rate is more than 30% higher than that of traditional ring coolers.

[0062] This vertical furnace body is a sealed cavity, and a large amount of high-temperature steel slag accumulates inside the vibrating discharge machine 320 and the distributor 140, forming a steel slag material blockage and reducing the possibility of air leakage. The hot air is drawn out by the cyclone dust collector 430, and the air leakage rate is close to zero (the air leakage rate of traditional annular coolers is as high as 30%-40%). This not only reduces heat loss but also increases the exhaust gas temperature (usually reaching over 400℃), making the waste heat more suitable for power generation or steam production.

[0063] Research on uniform air distribution and material distribution technology: The segregation of steel slag material particles and uneven distribution of cold air in this technology are achieved through the following techniques.

[0064] This technology solves the problem of uneven flow of steel slag material by combining a material distributor 140, an adjustable stacking height, and an air distributor 150, thereby achieving gas-solid synergistic heat exchange and ensuring the uniformity of heat exchange between high-temperature steel slag and cold air.

[0065] In this process, the heat exchange site is located in a closed furnace cavity. High-temperature steel slag enters from the top of the furnace body, while cooling air enters from the air distributor 150 at the bottom of the furnace body. The cooling of the steel slag and the recovery of sensible heat are achieved through the countercurrent heat exchange between the high-temperature steel slag and the cold air.

[0066] In traditional implementation techniques, the thickness of the steel slag pile is 4 to 5 times the inner diameter of the furnace cavity, and the material density is relatively high, reaching 1600 to 2000 kg / m³. 3Furthermore, due to the high porosity of the steel slag in contact with the furnace wall, a sidewall effect occurs at the inner wall, causing a large amount of cold air to escape from near the wall. This prevents the air from being evenly distributed within the material layer, resulting in a consistently higher temperature at the center of the material pile and thus uneven heat exchange. This technology addresses this problem by implementing non-falling feeding during the feeding stage. This prevents the steel slag material from forming a conical arrangement within the furnace cavity and avoids particle size segregation. The resulting uniform particle size of the steel slag near the furnace edge and center ensures consistent airflow distribution.

[0067] Meanwhile, by setting an air outlet on the cover 142 of the fabric distributor 140, the hot air outlet at the top is made more uniform and consistent, which is conducive to uniform cooling.

[0068] Meanwhile, this technology improves the structure of the air distributor 150 so that the air volume in the center is slightly greater than that in the surrounding area, thereby achieving a large air volume supply to the center of the furnace cavity and increasing the air volume at the center point.

[0069] The material moves downwards as a whole within the furnace cavity.

[0070] In traditional furnace structures, dead zones exist in the downward movement of steel slag, disrupting the overall flow and hindering the orderly input and output of high-temperature and low-temperature steel slag. This results in a lack of coordination between the slag material flow and energy flow, becoming another bottleneck restricting the improvement of gas-solid countercurrent heat exchange efficiency. Therefore, adjusting the segregation distribution and flow pattern of steel slag, loosening the density of the material layer, and ensuring uniform air distribution are the directions for improvement and essential requirements for enhancing the gas-solid heat exchange efficiency of vertical cooling furnaces.

[0071] Further improvements include the use of an electrically driven rotary material distributor 140, whose cover 142 incorporates umbrella-shaped and vertical chutes to create a uniform annular material pile within the cooling section. Additionally, an air distributor 150 is an annular air duct with 6 to 12 branch pipes. Together, these components achieve uniform material distribution at the top and uniform air distribution at the bottom, preventing large particles from accumulating on the sidewalls and small particles from accumulating in the center, and ensuring uniform flow of cold air.

[0072] The furnace cavity inner wall in this technology is made of refractory and smooth ceramic material, and will not cause significant resistance to the downward movement of steel slag, thus having the integrity of downward movement.

[0073] The implementation of this technology will involve the research and development of adjusting steel slag segregation, improving the overall downward flow of steel slag piles, optimizing feeding, and optimizing cold air distribution as a whole, so as to simultaneously improve the distribution and flow of steel slag and cold air, thereby improving gas-solid heat exchange efficiency.

[0074] After the implementation of this technology, steel slag segregation can be significantly improved, the steel slag pile can be made to flow in an "overall flow" manner in the furnace cavity, and the cold air can be distributed evenly in the steel slag pile. Ultimately, the steel slag and cold air can operate in opposite directions and in a uniform and coordinated manner.

[0075] This technology improves the material distributor 140 by changing it from a fixed-height distributor 140 to an adjustable distributor 140 with height adjustment capability. Specifically, the distributor 140 consists of multiple telescopic joints 141 nested together and a conical cover 142. Safety ropes 143 are installed between adjacent telescopic joints 141, connecting two adjacent telescopic joints 141. Multiple safety ropes 143 are installed, evenly distributed circumferentially. A cover 142, preferably conical, is installed at the lowest end of each telescopic joint 141. At least two wire rope drive mechanisms are provided, each consisting of a wire rope and an electric winch 130. The electric winch 130 is installed at the top outside the furnace cavity and adjusts the height of the telescopic joints 141 using the electric winch 130. The specific adjustment process is as follows: When a height adjustment is required, the electric winch 130 is used to adjust the height of the expansion joint 141. After adjustment, the steel slag will accumulate in the furnace cavity based on the increased height until the steel slag is arranged in a ring along the lowest point of the expansion joint 141 and forms a distribution. During this process, the steel slag material accumulates in the expansion joint 141 and gradually moves down to replenish it. There is no free fall process of the steel slag material, which can effectively alleviate the phenomenon of large particles being enriched on the side walls of the furnace cavity and small particles being enriched in the center of the furnace cavity. This makes the steel slag material more evenly distributed in the furnace cavity, thereby reducing the segregation of steel slag material particle size and making the steel slag material distribution more uniform. It also helps to improve the uniformity of the material layer's permeability, thereby making the cooling air evenly distributed in the material layer.

[0076] Furthermore, an air duct is provided on the conical surface of the cover 142, through which air can freely enter and exit the steel slag pile, thereby effectively avoiding the accumulation of air along the inner wall of the furnace cavity and promoting the uniformity of air distribution.

[0077] Furthermore, for small and medium-sized furnaces with an inner diameter of less than 8 meters, the projected area of ​​the cover 142 is slightly smaller than the inner cavity of the furnace, and a 10-centimeter annular gap is formed in the circumferential direction, which also serves as a ventilation opening for air.

[0078] Furthermore, a rolling assembly 144, such as a rolling wheel set, is provided along the edge of the cover 142. The rolling wheel set contacts the inner wall of the furnace cavity to improve flexibility. During the material distribution process, the steel slag material in the distributor 140 is slowly released from top to bottom. There is no free fall motion, which completely solves the problem of steel slag material particle size segregation, making the steel slag material distribution more uniform. It also helps to improve the uniformity of material layer permeability, thereby making the cooling air evenly distributed in the material layer.

[0079] Furthermore, the cover 142 of the feeder 140 has undergone technical improvements. Specifically, the cover 142 is designed for a larger size, for example, for furnace cavities with a diameter of 8 meters or more. Multiple feeding pipes are installed on the upper part of the cover 142, and each feeding pipe corresponds to a set of expansion joints 141, converging at the top into a single main feed pipe, thereby achieving multi-point feeding. (Reference) Figure 11 .

[0080] The material distributor 140 is mechanically engaged with the inner wall of the furnace cavity through the rolling assembly 144, and can bear part of the horizontal load. This keeps the material distributor 140 in a centered position, which reduces the density of the steel slag material, facilitates the reverse flow of cooling air, and allows for sufficient heat exchange, thus improving the distribution of cooling air in the material layer.

[0081] Meanwhile, the expansion joint 141 in this technology controls its outlet height according to the temperature characteristics and particle characteristics of different batches of steel slag materials.

[0082] The expansion joint 141 and the cover 142 in this technology are made of alloy steel with good high temperature resistance.

[0083] A further improvement is made by providing a powered cover 142 at the bottom of the cover 142, which is rotatable, i.e. has a rotation function.

[0084] Furthermore, the cover 142 is provided with multiple ribs inside, which form a support to improve the rigidity of the cover 142, and a cone is provided in the middle of the cover 142 to achieve uniform feeding in four directions.

[0085] In this technology, the material distributor 140 directly conveys the steel slag material to the material pile, preventing the steel slag material from rolling towards the side wall. This allows the steel slag material inside the furnace cavity to move downwards, thus achieving the translational propulsion of the steel slag material in the vertical direction.

[0086] By lining the inner surface of the furnace cavity with a highly smooth, wear-resistant material, such as a wear-resistant and high-temperature-resistant special ceramic coating, the downward force of the steel slag material near the wall is always greater than the wall friction force. This avoids flow dead zones caused by poor downward movement of the steel slag material near the wall, promoting a "whole-body flow" of the steel slag material. Under this flow pattern, all the steel slag material in the furnace cavity flows at a constant speed, avoiding the wall's obstruction of the downward movement of nearby steel slag material.

[0087] The uniform distribution of steel slag particles in the slag pile further promotes the uniform upward propagation of cooling air, thereby improving the gas-solid heat exchange efficiency and making the cooling air distribution more uniform, thus improving gas-solid contact heat exchange.

[0088] In addition, when the steel slag material passes through the furnace cavity, the equal area cross section causes the steel slag material to move downward as a whole, resulting in a gradient configuration of the temperature of the steel slag material from top to bottom.

[0089] Preferably, an air cap is installed at the top air outlet of the air distributor 150. The air cap makes the cooling air distribution in the furnace cavity more uniform, thereby increasing the gas-solid contact heat exchange area of ​​the material layer in the furnace. The air cap itself is equivalent to the function of modifying steel slag, which can reduce the downward movement speed of steel slag material in the central area of ​​the furnace cavity, and also helps to improve the overall stability of the downward movement of steel slag material.

Claims

1. A device for recovering sensible heat from high-temperature steel slag bulk material, comprising a shaft furnace built with refractory material, wherein the internal furnace chamber of the shaft furnace is sequentially divided into a feeding and hot air collecting section, a high-temperature heat exchanging section, a medium-temperature heat exchanging section, and a low-temperature cooling section from top to bottom, and the top of the shaft furnace is provided with an equipment platform, and the bottom of the shaft furnace is provided with a discharging device, characterized in that: The feeding and hot air collection section is equipped with a material distributor mechanically connected to the feeding pipe. The material distributor consists of multiple telescopic joints nested together and a conical cover. Safety ropes are installed between adjacent telescopic joints, and a cover is installed at the bottom of the telescopic joint. At least two wire rope drive mechanisms are also provided, each consisting of a wire rope and an electric winch. Driven by the winch installed on the equipment platform, the material distributor has a height adjustment function. The lower outlet of the material distributor is inserted into the top of the slag pile, and the material distributor and the feeding pipe are in a full state. An air collecting ring cavity is provided on the furnace body of the feeding and hot air collection section, surrounding the feeding pipe. Multiple windows are provided on the inclined partition of the air collecting ring cavity, through which hot air from the top of the furnace cavity is introduced to the air collecting ring cavity. The hot air pipe collects the hot air in the air collecting ring cavity and discharges it to the cyclone dust collector. An air distributor is installed in the inner cavity of the low-temperature cooling section, and the air distributor is externally connected to a blower.

2. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, The edge of the cover is provided with a rolling component, and the material distributor is mechanically engaged with the inner wall of the furnace cavity through the rolling component.

3. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, The space below the material distributor in the furnace cavity is filled with steel slag.

4. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, A roller screen is installed to screen out steel slag blocks larger than 80mm, while hot steel slag smaller than 80mm is lifted by a feeding trolley and added into the vertical furnace.

5. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, The air distributor uses a ring-shaped arrangement with multiple cold air ducts, which are unevenly spaced in the vertical direction.

6. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, An air outlet is provided on the cover of the fabric feeder.

7. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, The fabric feeder is an electrically operated rotary fabric feeder.

8. The high-temperature steel slag bulk material sensible heat recovery device according to claim 1, characterized by, The inner wall of the furnace cavity is fitted with refractory and smooth ceramic.

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