High-temperature liquid slag waste heat recovery device and use method

Abstract

The present invention relates to the technical field of high-temperature liquid slag waste heat recovery. Disclosed are a high-temperature liquid slag waste heat recovery device and a use method. The high-temperature liquid slag waste heat recovery device comprises a slag temporary storage and flow control device, a slag heat exchange device and a discharge device, wherein the slag heat exchange device is provided with a cavity, and a material leveling device, a cooling buried pipe and an air distribution plate are comprised in the cavity in sequence; the air distribution plate is arranged at the lower part of the slag heat exchange device; the material leveling device and the cooling buried pipe are arranged inside the cavity of the slag heat exchange device; the material leveling device is provided with a hollow structure, and the interior of the hollow structure is in communication with the exterior of the slag heat exchange device so as to perform heat exchange by means of a cooling medium; and an inlet of the discharge device is in communication with a bottom outlet of the slag heat exchange device. By means of the liquid slag temporary storage and flow control device, the problems of temperature fluctuation and mismatch between granulation and waste heat recovery caused by intermittent slag discharge from a blast furnace are solved; and the heat exchange efficiency of slag is improved by the heat exchange device and the material leveling device, smooth discharge is ensured, and remelting and slag particle accumulation are reduced.

Description

A high-temperature liquid slag waste heat recovery device and its usage method Technical Field

[0001] This invention relates to the field of high-temperature liquid molten slag waste heat recovery technology, and particularly to a high-temperature liquid molten slag waste heat recovery device and its usage method. Background Technology

[0002] The metallurgical industry is a vital pillar of the national economy, providing crucial raw material security for economic development. However, it also involves enormous energy consumption and pollutant emissions. The smelting of pig iron generates blast furnace slag, which contains a tremendous amount of heat; the sensible heat contained in each ton of slag is equivalent to 60 kg of standard coal.

[0003] Currently, blast furnace slag is mostly treated using water quenching and dry granulation methods. Water quenching consumes an astonishing amount of water, requiring 0.8 to 1.2 tons of fresh water per ton of slag, with approximately 10 tons of water recycled. This not only wastes a significant amount of water resources but also potentially pollutes the environment. Furthermore, water quenching fails to recover the waste heat from the blast furnace slag, leading to heat waste. While different water quenching methods differ in their process flow, they all share common drawbacks: ineffective recovery of waste heat resources from the molten slag, waste of large amounts of water resources, air pollution, and additional energy consumption.

[0004] In contrast, dry granulation has significant advantages such as not consuming water resources, low pollution emissions, and the ability to utilize high-grade waste heat. This method can achieve energy conservation and environmental protection while obtaining products with uniform particle size and high added value, thus gradually becoming a key area of ​​research and industrial application. However, dry granulation still faces many technical bottlenecks in actual operation, such as low heat recovery efficiency, high system energy consumption, and large slag particle size with insufficient glass content, thereby limiting its application potential in high-value-added resource utilization.

[0005] Currently, most dry heat recovery devices combine centrifugal granulation with moving bed heat exchange, using air as the primary heat exchange medium. However, when the operating conditions of blast furnace slag discharge and waste heat recovery devices are mismatched, problems such as slow cooling rates, low glass content, high-temperature particle accumulation and remelting, and low heat recovery efficiency still exist. In addition, the granulation bin and moving bed system have complex structures and high operating and maintenance costs, reducing overall economic efficiency.

[0006] Currently, these treatment methods are no longer adequate to meet the urgent needs of the steel industry for energy conservation and emission reduction. Therefore, a new high-temperature liquid slag waste heat recovery device is urgently needed. Summary of the Invention

[0007] To address existing problems, this invention provides a reasonably designed, practical, and convenient high-temperature liquid molten slag waste heat recovery device and its usage method. It aims to overcome the technical bottleneck caused by the intermittent slag discharge of blast furnaces, which leads to fluctuations in molten slag flow and temperature, and the mismatch between granulation and waste heat recovery processes, thus ensuring the stable operation of the centrifugal granulation system.

[0008] To achieve the above objectives, the present invention provides the following technical solution.

[0009] A high-temperature liquid molten slag waste heat recovery device includes a molten slag buffer and flow control device, a molten slag heat exchange device, and a discharge device. The molten slag heat exchange device is provided with a cavity, and a leveling device, a cooling buried pipe, and an air distribution plate are arranged inside the cavity. The air distribution plate is arranged at the lower part of the molten slag heat exchange device. The cooling buried pipe is arranged above the air distribution plate, and the leveling device is arranged above the cooling buried pipe. The leveling device is provided with a hollow structure, and the interior of the hollow structure is connected to the exterior of the molten slag heat exchange device to exchange heat through a cooling medium. The inlet of the discharge device is connected to the bottom outlet of the molten slag heat exchange device.

[0010] Preferably, the leveling device adopts a steel frame structure, and the steel frame structure forms a slope from the center to both sides; the leveling device is equipped with rake nails.

[0011] Preferably, the slag buffer and flow control device further includes a sidewall air device; the sidewall air device is disposed at the top of the cavity of the slag heat exchange device.

[0012] Preferably, the top of the molten slag heat exchanger is provided with a hot air collecting flue. The air enters the inner cavity of the molten slag heat exchanger through the air distribution plate and the side wall air device, and after heat exchange and temperature rise, it floats upward and is discharged from the hot air collecting flue.

[0013] Preferably, the slag buffer and flow control device includes a stopper rod operating port, a stopper rod, a radar level gauge, and a slag discharge pipe; the radar level gauge and the stopper rod operating port are located above the slag buffer and flow control device; one end of the stopper rod is located inside the stopper rod operating port to control the flow rate of the slag through the feeding of the stopper rod; the slag buffer and flow control device is connected to the slag heat exchange device through the slag discharge pipe.

[0014] Preferably, the slag buffer and flow control device further includes a weighing sensor; the weighing sensor is disposed at the bottom of the slag buffer and flow control device.

[0015] Preferably, it also includes a heating surface; the heating surface is vertically suspended inside the cavity of the molten slag heat exchanger; the heating surface is also disposed on the inner wall of the cavity of the molten slag heat exchanger.

[0016] Preferably, the cavity inside the leveling device is vented with a cooling medium through a medium heat exchange tube, and the medium heat exchange tube moves linearly or rotary relative to the molten slag heat exchange device through bearing balls.

[0017] Preferably, the leveling device is movably connected to the molten slag heat exchange device.

[0018] A method for using a high-temperature liquid molten slag waste heat recovery device includes the following steps:

[0019] High-temperature molten slag enters the molten slag buffer and flow control device;

[0020] High-temperature molten slag enters the molten slag heat exchanger, and the air distribution plate is activated to ventilate and exchange heat in the upper part of the inner cavity.

[0021] Start the cooling buried pipe to exchange heat with the cooling medium in the lower part of the molten slag heat exchange device;

[0022] The high-temperature molten slag falls onto the leveling device and breaks down into loose particles.

[0023] The present invention has the following beneficial effects:

[0024] The design of this invention, combining a slag buffer and flow control device with a slag heat exchanger, effectively recovers waste heat from high-temperature liquid slag. The slag buffer and flow control device regulates the slag flow rate, ensuring a stable and continuous entry of slag into the heat exchanger, thereby improving the efficiency and stability of waste heat recovery. The leveling device disperses the granulated slag generated by the centrifugal granulation cup, facilitating its sliding to the bottom of the inner cavity. The cooling embedded pipe forms a cold source at the bottom of the inner cavity, effectively exchanging heat with the slag heat exchanger using a cooling medium. The leveling device features a hollow structure, the interior of which is connected to the exterior of the slag heat exchanger. This breaks up and loosens the initially formed granulated slag, further cooling and hardening it through heat exchange with the cooling medium to prevent remelting, adhesion, and slag accumulation. The discharge device promptly discharges the slag after heat exchange, preventing its accumulation in the slag heat exchanger and maintaining its smooth and efficient operation. The discharge device also enables slag cooling and recovery, contributing to resource reuse.

[0025] Preferably, the steel frame structure has high strength and can withstand the weight of the molten slag and the high temperature environment, ensuring the stability and durability of the leveling device during long-term operation; the steel frame forms a slope from the center to both sides, which facilitates the natural sliding and rolling of the granulated molten slag, increases the relative movement and heat exchange between the molten slag and air, and effectively prevents remelting and adhesion and molten slag accumulation.

[0026] Preferably, the rake nail can enhance the stirring and uniform distribution of molten slag by the leveling device, prevent molten slag from accumulating or forming dead corners during the heat exchange process, and improve heat exchange efficiency; the rake nail can be activated when overheating or sticking, enhance the discharge function of the leveling device, and increase the heat dissipation rate at the same time.

[0027] Preferably, the movable connection facilitates the maintenance and replacement of the leveling device, and also allows for adjustment of the position and angle of the leveling device according to actual needs, so as to meet the requirements of slag waste heat recovery under different working conditions; the movable connection can also be connected to a vibration device to perform low-amplitude translation or rotational oscillation of the leveling device.

[0028] Preferably, the stopper rod operating port, stopper rod, radar level gauge, and slag discharge pipe work together to achieve precise control of the molten slag flow rate, ensuring that the molten slag enters the molten slag heat exchanger as needed, avoiding reduced heat exchange efficiency due to excessive or insufficient flow. The radar level gauge can record the liquid level changes during molten slag buffering in real time, and the weighing sensor can record the weight changes during molten slag outflow in real time, realizing real-time monitoring of dynamic molten slag outflow and static buffering, ensuring the safe and stable operation of the system.

[0029] Preferably, the weighing sensor can monitor the weight of the slag in the slag buffer and flow control device in real time, providing accurate data support for controlling the slag flow rate and further improving the accuracy and stability of waste heat recovery.

[0030] Preferably, the suspended screen heating surface can enhance the disturbance of airflow, improve the heat transfer coefficient by utilizing the thermal convection of gas, and increase the heat transfer contact area. It is also conducive to the uniform distribution and flow of molten slag, further improving the waste heat recovery efficiency.

[0031] Preferably, the inner wall heating surface can increase the heating area between the molten slag and the cooling medium, improve the heat exchange efficiency, and thus more effectively recover the waste heat of the molten slag.

[0032] Preferably, the side wall air device can provide an appropriate amount of cooling air to the cavity of the slag heat exchanger, enhance the heat exchange effect between the slag and the cooling medium, and at the same time help prevent the slag from forming coke or adhering on the cavity wall, keeping the heated surface clean and efficient. Attached Figure Description

[0033] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and are not intended to specifically limit the shapes and proportions of the components. In the drawings:

[0034] Figure 1 is a schematic diagram of a high-temperature liquid slag waste heat recovery device according to an embodiment;

[0035] Figure 2 is a schematic diagram of the linear motion of the leveling device in a high-temperature liquid slag waste heat recovery device according to the embodiment;

[0036] Among them, 1. Slag buffer and flow control device; 2. Slag heat exchange device; 3. Discharge device; 4. Stopper rod; 5. Radar level gauge; 6. Weighing sensor; 7. Slag discharge pipe; 8. Heating surface; 9. Leveling device; 10. Cooling buried pipe; 11. Air distribution plate; 12. Side wall air device; 13. Hot air collection flue; 14. Medium heat exchange tube. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0038] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] Example

[0041] As shown in Figure 1, the present invention provides a high-temperature liquid molten slag waste heat recovery device. The device is arranged from top to bottom and includes a molten slag buffer and flow control device 1, a molten slag heat exchange device 2, and a discharge device 3.

[0042] The slag buffer and flow control device 1 includes a stopper rod 4, a radar level gauge 5, a weighing sensor 6, and a slag discharge pipe 7. The slag buffer and flow control device 1 has a cylindrical basin-shaped structure with an internal cavity. A stopper rod operating port is located at the upper center of the slag buffer and flow control device 1, through which molten slag enters the internal cavity. One end of the stopper rod 4 is located inside the stopper rod operating port, and the feeding of the stopper rod 4 cooperates with the stopper rod operating port to control the entry of molten slag into the internal cavity of the slag buffer and flow control device 1. The stopper rod 4 has a rod-shaped structure and is made of a special material that is resistant to high temperatures and slag erosion (such as high-alumina or silicon carbide).

[0043] A radar level gauge 5 is also installed above the liquid slag buffer and flow control device 1. The radar level gauge 5 is used to measure the liquid level change during the slag buffering process in real time, so that the amount of slag buffered meets the capacity requirements of the slag buffer and flow control device 1.

[0044] The radar level gauge 5 is an industrial-grade radar level measuring device, consisting of a transmitter, a receiver, and a signal processor. It is installed above the slag buffer and flow control device 1, with the probe facing the slag surface inside the buffer device without direct contact with the slag. It monitors the slag level in the slag buffer and flow control device 1 in real time to prevent overflow due to excessively high levels or flow interruption due to excessively low levels. The level signal is transmitted to the control system, which is linked with the stopper rod 4 for adjustment. When the level is too high, the stopper rod is retracted to increase the flow rate; when the level is too low, the stopper rod is fed forward to reduce the flow rate, ensuring a stable buffer volume.

[0045] The slag discharge pipe 7 is connected at both ends to the bottom outlet of the slag buffer and flow control device 1 and the top inlet of the slag heat exchange device 2, respectively. The inner channel of the pipe is smooth to prevent slag from adhering to the wall and accumulating. The slag discharge pipe 7 is a tubular structure made of heat-resistant steel that is resistant to high temperatures and wear. A weighing sensor 6 is also installed on the right side of the slag discharge pipe 7. The weighing sensor 6 is used to monitor the change in the mass of the slag buffer and flow control device 1 in real time when the slag flows out. After entering the slag buffer and flow control device 1, the liquid slag enters the slag heat exchange device 2 through the slag discharge pipe 7.

[0046] The weighing sensor 6 is a piezoelectric or strain gauge weighing sensing element, usually in the form of a block or sheet; it is installed on the side of the slag discharge pipe 7 and in contact with the support structure of the buffer device to indirectly measure the total weight of the device and the molten slag inside, monitor the weight change of the molten slag in the molten slag buffer and flow control device 1 in real time, and calculate the actual outflow of molten slag by the weight difference.

[0047] The slag discharge pipe 7 is a tubular structure made of heat-resistant steel that is resistant to high temperatures and wear. It smoothly transports the molten slag that flows out stably from the molten slag buffer and flow control device 1 to the molten slag heat exchange device 2, avoiding splashing and excessive heat dissipation of the molten slag during the transmission process. It also works with the stopper rod 4 to achieve flow control: the gap between the slag discharge pipe inlet and the stopper rod is the key adjustment point for the molten slag flow rate.

[0048] Optionally, the stopper rod 4 can also be connected to the slag discharge pipe 7 by extending into it. The feeding of the stopper rod 4 is coordinated with the slag discharge pipe 7 to control the entry of liquid molten slag into the molten slag heat exchange device 2.

[0049] Optionally, the radar level gauge 5 and the weighing sensor 6 can also be linked with the stopper rod 4 to control the feed of the stopper rod 4, thereby controlling the gap between the stopper rod 4 and the stopper rod operating port or the slag discharge pipe 7, so as to achieve the purpose of controlling the slag flow rate according to the granulation requirements of the subsequent granulation unit. The linkage between the radar level gauge 5 and the weighing sensor 6 to control the feed of the stopper rod 4, thereby controlling the flow rate in real time, ensures the stability of the flow rate and ensures that the operation of the blast furnace slag discharge and the waste heat recovery unit are matched.

[0050] The molten slag heat exchanger 2 includes a heating surface 8, a leveling device 9, a cooling embedded pipe 10, an air distribution plate 11, and a sidewall air device 12. The molten slag heat exchanger 2 is a box-like structure located below the molten slag buffer and flow control device 1. An air distribution plate 11 is horizontally installed at the bottom of the molten slag heat exchanger 2, with holes on the plate for air supply. The angle of the air distribution plate 11 and the diameter and spacing of the holes can be adjusted according to the air supply requirements of the molten slag heat exchanger 2. The airflow direction of the air distribution plate 11 is opposite to the movement direction of the slag particles. This counter-current flow increases the temperature difference between the molten slag and the incoming air from the air distribution plate 11, effectively enhancing the convective heat transfer effect of the molten slag and improving the stability of heat transfer. Adjustable dampers or valves can be introduced into the air distribution plate 11 to automatically adjust the sidewall airflow according to the flow rate and temperature of the molten slag. The air distribution plate 11 itself is designed using high-temperature resistant and corrosion-resistant fan and pipe materials to improve the reliability and service life of the sidewall air device.

[0051] The cross-section of the slag heat exchanger 2 can gradually increase from the air distribution plate 11 upwards to increase ventilation space and heating area, and then gradually decrease to form a wind-resistant cyclone to increase convective heat transfer. Cooling pipes 10 are arranged on the upper part of the air distribution plate 11, and the direction of the cooling pipes 10 is perpendicular to the air supply direction of the air distribution plate 11. The air outlets on the air distribution plate 11 are evenly spaced to achieve uniform heat transfer of the slag, and counter-current airflow is used to increase the convective heat transfer effect of the slag.

[0052] The cooling buried pipe 10 is horizontally positioned above the air distribution plate 11 within the dense phase zone of the flat material device 9 (referring to the area where slag particles are densely packed). Different arrangements and extended heating surfaces 8 are used to enhance heat exchange. These arrangements include, but are not limited to, mesh arrangements, staggered square arrangements, and concentric circle arrangements. The heating surfaces 8 can be equipped with fins, including but not limited to annular fins, internal fins, spiral fins, and corrugated fins. The heating surfaces 8 are arranged in the high-temperature particle heat exchange area of ​​the molten slag heat exchange device 2, including but not limited to the cavity top heating surface, the suspended screen heating surface, and the flat material device heating surface, ensuring that the high-temperature molten slag can undergo sufficient heat exchange throughout the entire space, while simultaneously preventing excessively high wall temperatures and reducing external heat loss.

[0053] The cooling submerged tubes 10 are horizontally positioned below the dense phase zone of the leveling device 9, employing a staggered arrangement and an extended heating surface 8 to ensure thorough and uniform heat exchange for the slag particles as they pass through the leveling device 9. Cooling water circulates within the cooling submerged tubes 10, circulating inside and outside the molten slag heat exchanger 2, thus cooling the slag particles and recovering waste heat. The flow path and velocity of the cooling submerged tubes 10 can also be adjusted according to the required heat exchange rate.

[0054] As shown in Figures 1 and 2, a leveling device 9 is installed above the cooling pipe 10. The leveling device 9 adopts a steel frame structure, with an external trapezoidal shape, higher in the middle and lower on both sides, and a hollow interior. The steel frame is made of heat-resistant steel columns. The gaps in the steel frame are sufficient to allow granulated molten slag to fall off, preventing slag blockage. The leveling device 9 has a hollow structure, the interior of which is connected to the exterior of the molten slag heat exchange device 2. This breaks up and loosens the initially formed granulated molten slag, and further cools and hardens the slag through heat exchange with the cooling medium, preventing remelting, adhesion, and slag accumulation. The contact with the steel frame allows for heat exchange between the molten slag and the steel frame, further cooling the slag. Cooling medium is circulated inside the hollow interior of the leveling device 9. Through medium circulation, the thermal stress of the steel frame is reduced, enhancing the thermal protection of the device and increasing the heat exchange capacity of the molten slag. The cooling medium includes, but is not limited to, air, water, and heat transfer oil.

[0055] The cavity inside the leveling device 9 is vented with cooling medium through the medium heat exchange tube 14. The medium heat exchange tube 14 performs the linear or rotary motion of the molten slag heat exchange device 2 through the bearing ball. Its structure and principle are shown in Figure 2.

[0056] The medium heat exchange tube 14 has a thin tubular structure and is made of a metal tube with high thermal conductivity and high temperature resistance (such as copper alloy or heat-resistant steel). The medium (such as air, water or heat transfer oil) circulates in the tube to remove the heat of the molten slag absorbed by the leveling device 9, thereby reducing the temperature of the leveling device 9 and preventing it from deforming or being damaged due to high temperature. The cooling medium exchanges heat indirectly with the molten slag through the wall of the leveling device 9, further reducing the temperature of the slag particles, preventing remelting, and increasing the amount of waste heat recovery.

[0057] The leveling device 9 is hydraulically driven and uses bearing balls to achieve linear or rotary motion, ensuring that the leveling device 9 has a sufficiently large output force and range of action.

[0058] The bearing ball has a spherical structure, and its diameter is designed according to the size of the flattening device 9. The material is a wear-resistant material with high temperature resistance and high hardness (such as heat-resistant steel ball or ceramic ball). It is installed at the connection gap between the flattening device 9 and the inner wall of the slag heat exchange device 2, serving as a rolling support for the relative movement of the two. The rolling of the bearing ball reduces the frictional resistance of the flattening device when it moves in a straight line or rotates.

[0059] Optionally, the driving method of the leveling device 9 may include, but is not limited to, pneumatic and electric drive, to realize the linear or rotary motion of the leveling device 9. Generally, smaller granulation requirements correspond to smaller leveling devices 9, which are suitable for electric drive; larger granulation requirements correspond to larger leveling devices 9, which are suitable for pneumatic or hydraulic drive.

[0060] As shown in Figure 2, the leveling device 9 can also be a steel plate structure, with the cooling embedded pipe 10 installed inside, and the cooling medium circulating heat to the leveling device 9.

[0061] Optionally, rakes can be added to the upper part of the leveling device 9 to enhance the loosening ability of slag particles, improve the waste heat recovery effect, and effectively prevent slag particles from sticking and accumulating. The rakes can be symmetrically arranged on both sides according to the granulation rotor, which can break and loosen the molten slag that is too large to fall naturally after granulation.

[0062] Optionally, a roll crushing device can be added to the upper part of the leveling device 9. The roll crushing devices are symmetrically arranged on both sides of the granulation rotor. The roll crushing devices consist of several pairs of air-cooled roll crushing devices. The two ends of the air-cooled roll crushing devices are connected to the molten slag heat exchange device 2. Each pair of air-cooled roll crushing devices rotates in a different direction. The air-cooled roll crushing devices cut larger slag blocks or slag cotton clumps. After being crushed by the air-cooled roll crushing devices, the larger slag blocks or slag cotton clumps are formed into smaller slag blocks, which continue to exchange heat in the molten slag heat exchange device 2.

[0063] The air-cooled roll crushing device is a pair of air-cooled roll structures made of heat-resistant and wear-resistant materials. Each pair of rolls rotates in opposite directions, and cooling air is introduced into the interior to reduce the temperature. The roll surface is adapted to crushing requirements and is used to cut large-diameter slag blocks or slag clumps to make the slag particles more uniform and improve heat exchange efficiency.

[0064] The slag heat exchanger 2 has heating surfaces 8 inside and on its walls to effectively enhance heat exchange intensity and prevent excessive wall temperature. A suspended heating screen 8 is installed inside the slag heat exchanger 2 to enhance heat exchange efficiency while preventing the high-temperature slag from remelting. The cavity of the slag heat exchanger 2 can be made of heat-resistant and highly thermally conductive materials, such as heat-resistant steel or carbon steel; the inner wall also serves as a heating surface 8, absorbing convective heat transfer from the air inside the cavity and thermal radiation from the heating surface 8 within the cavity.

[0065] Optionally, the slag heat exchanger 2 may be equipped with finned tubes, nail-head tubes, spray tubes or special-shaped tubes to further promote heat exchange of slag particles and disperse slag particles for uniform heat exchange.

[0066] Above the inner sidewall of the molten slag heat exchanger 2, sidewall air devices 12 are evenly arranged circumferentially. An airflow is introduced into the upper part of the molten slag heat exchanger 2, directly supplying airflow for heat exchange to the slag drop pipe 7 and the heating surface 8. The airflow blown upward by the air distribution plate 11 is diverted through the cooling buried pipe 10 and the leveling device 9, and enters the upper space of the molten slag heat exchanger 2 along the sidewall, forming an upward airflow that meets and mixes with the sidewall airflow blown in from the top. The mixed air cyclone generates a thermal convection effect, resulting in higher heat exchange efficiency. The incident angle and flow rate of the sidewall air can be adjusted in real time according to the molten slag flow rate, temperature, and rotor speed to ensure optimal granulation effect and increase heat exchange efficiency. When uniform cooling of slag particles is required, sidewall air with the same direction and velocity can be used. When enhanced thermal protection of the wall surface is required, different sidewall air devices 12 can be adjusted to have different incident angles and velocities, thereby enhancing spatial turbulence and protecting the wall surface of the molten slag heat exchanger 2.

[0067] The side wall air device 12 consists of an air inlet pipe, nozzles, and flow / angle regulating valves. It is made of heat-resistant steel and is evenly installed on the top side wall of the cavity of the molten slag heat exchange device 2. The nozzles face the inside of the cavity and the air inlet angle and flow rate can be changed by regulating valves.

[0068] The hot air collection flue 13 is a flue-type or tubular structure, made of high-temperature resistant and corrosion-resistant steel (such as stainless steel).

[0069] The top of the slag heat exchanger 2 is equipped with a hot air collection flue 13. The air distribution plate 11 and the side wall air device 12 blow two streams of air into the inner cavity of the slag heat exchanger 2. After heat exchange and heating, the air floats upward and is discharged from the hot air collection flue 13. The heat is recovered by the waste heat boiler and then discharged into the atmosphere by the dust removal device or merged into the air inlet of the air distribution plate 11 or the side wall air device 12.

[0070] The recovered hot air can be introduced into the waste heat boiler. The inlet section of the pipeline is equipped with a primary dust collector to ensure the safe operation of the waste heat boiler.

[0071] A discharge device 3 is installed below the molten slag heat exchanger 2, with its inlet connected to the outlet of the molten slag heat exchanger 2. The outlet of the molten slag heat exchanger 2 is lower than the air outlet of the air distribution plate 11, thus avoiding airflow obstruction of slag discharge and slag accumulation that could cause particle remelting and adhesion. The discharge device 3 itself is constructed using wear-resistant and high-temperature-resistant materials to improve its service life and reliability.

[0072] The discharge device 3 employs a water-cooled spiral slag cooler or a drum slag cooler. The cooling medium includes, but is not limited to, air cooling, water cooling, and a combination of air and water cooling. The slag cooler includes, but is not limited to, the use of a water-cooled jacket, internal ventilation, the addition of baffles, and internal multi-zone division to enhance heat exchange efficiency. Using a water-cooled spiral slag cooler or a drum slag cooler for discharge allows for automatic adjustment of the slag discharge capacity based on the slag volume. Simultaneously, water-cooled jackets, internal ventilation, and internal baffles are used to enhance heat exchange of the slag particles.

[0073] In summary, this invention integrates a slag buffer and flow control device 1, an enhanced heat exchange device 2, and a discharge device 3 into one unit, thereby achieving high-temperature slag flow control and sufficient cooling, enhancing waste heat recovery, and effectively preventing the accumulation and remelting of high-temperature slag particles, thus ensuring the safe and stable operation of the system.

[0074] The method of using the high-temperature liquid molten slag waste heat recovery device in this embodiment is as follows:

[0075] High-temperature molten slag enters the liquid slag buffer and flow control device 1. The molten slag level is confirmed by the radar level gauge 5 to ensure that it meets the buffer requirements. At the same time, the feed of the stopper rod 4 is controlled by the linkage of the weighing sensor 6 to ensure that the molten slag outflow meets the requirements of the granulation device, thus achieving seamless connection between the smelting furnace and the granulation device.

[0076] After the high-temperature molten slag enters the molten slag heat exchanger 2, it undergoes radiative heat exchange with the top heating surface 8, the side wall air device 12, the suspended screen heating surface 8, the cooling buried pipe 10, and the discharge device 3 heating surface 8 in sequence, so that the high-temperature liquid molten slag changes from a molten state to a solid state. The higher heat exchange rate can effectively increase the glass content in the slag particles.

[0077] Meanwhile, the high-temperature molten slag particles in the dense phase buried pipe area of ​​the flat material device 9, the dilute phase area of ​​the suspended screen heating surface 8 (referring to the area where the slag particles are dispersed), the molten slag heat exchange device 2, and the discharge device 3 respectively undergo convective heat exchange with the air distribution plate 11 and the air from the discharge device 3. The air after heat exchange merges with the side wall air and enters the waste heat boiler to further realize waste heat recovery.

[0078] The discharge device 3 further exchanges heat with the slag particles while realizing the transportation and transfer of the slag particles, thus reducing energy consumption.

[0079] The linkage design in this embodiment can incorporate advanced programmable logic controllers (PLCs) or distributed control systems (DCS) to monitor and control the entire waste heat recovery process. It integrates sensor data, such as temperature, pressure, flow rate, and liquid level, for real-time monitoring and feedback control. This enables remote monitoring and fault diagnosis, improving system reliability and maintenance efficiency.

[0080] In addition, temperature sensors, pressure sensors, and alarm devices are installed in key areas to monitor the system's operating status in real time. Emergency shutdown and emergency discharge devices are introduced to deal with possible abnormal situations. Professional training is provided to operators to improve their ability to operate and maintain the system.

[0081] 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. Although embodiments of the present invention have been shown and described, it will be understood by those skilled 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. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-temperature liquid molten slag waste heat recovery device, characterized in that, It includes a slag buffer and flow control device (1), a slag heat exchange device (2), and a discharge device (3); the slag heat exchange device (2) is provided with a cavity, and a leveling device (9), a cooling buried pipe (10), and an air distribution plate (11) are provided inside the cavity; the air distribution plate (11) is provided at the lower part of the slag heat exchange device (2); the cooling buried pipe (10) is provided above the air distribution plate (11), and the leveling device (9) is provided above the cooling buried pipe (10); the leveling device (9) is provided with a hollow structure, and the interior of the hollow structure is connected to the exterior of the slag heat exchange device (2) to exchange heat through the cooling medium; the inlet of the discharge device (3) is connected to the bottom outlet of the slag heat exchange device (2).

2. The high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, The leveling device (9) adopts a steel frame structure, and the steel frame structure forms a slope from the center to both sides; the leveling device (9) is equipped with rake nails.

3. The high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, The slag buffer and flow control device (1) also includes a side wall air device (12); the side wall air device (12) is located at the top of the cavity of the slag heat exchange device (2).

4. The high-temperature liquid molten slag waste heat recovery device according to claim 3, characterized in that, The top of the slag heat exchanger (2) is provided with a hot air collection flue (13). The air enters the inner cavity of the slag heat exchanger (2) through the air distribution plate (11) and the side wall air device (12), and floats upward after heat exchange and temperature rise, and is discharged from the hot air collection flue (13).

5. The high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, The slag buffer and flow control device (1) includes a stopper rod operating port, a stopper rod (4), a radar level gauge (5), and a slag discharge pipe (7); the radar level gauge (5) and the stopper rod operating port are located above the slag buffer and flow control device (1); one end of the stopper rod (4) is located inside the stopper rod operating port so as to control the flow rate of slag by feeding the stopper rod (4); the slag buffer and flow control device (1) is connected to the slag heat exchange device (2) through the slag discharge pipe (7).

6. The high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, The slag buffer and flow control device (1) also includes a weighing sensor (6); the weighing sensor (6) is located at the bottom of the slag buffer and flow control device (1).

7. The high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, It also includes a heating surface (8); the heating surface (8) is vertically suspended inside the cavity of the slag heat exchanger (2); the heating surface (8) is also disposed on the inner wall of the cavity of the slag heat exchanger (2).

8. The high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, The cavity inside the leveling device (9) is vented with cooling medium through a medium heat exchange tube (14), which moves linearly or rotationally relative to the slag heat exchange device (2) via a bearing ball.

9. A high-temperature liquid molten slag waste heat recovery device according to claim 1, characterized in that, The leveling device (9) is movably connected to the slag heat exchange device (2).

10. A method of using a high-temperature liquid slag waste heat recovery device according to any one of claims 1 to 9, comprising the following steps: High-temperature molten slag enters the molten slag buffer and flow control device (1); High-temperature molten slag enters the molten slag heat exchange device (2), and the air distribution plate (11) is activated to ventilate and exchange heat to the upper part of the inner cavity; Start the cooling buried pipe (10) to exchange the cooling medium heat in the lower part of the molten slag heat exchange device (2); The high-temperature molten slag falls onto the leveling device (9) and is broken and loosened.

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