Thermal-state slag granulation system with visual material injection and granulation method

Abstract

The invention relates to a thermal-state slag granulation system with visual material injection and a granulation method. The system comprises a granulation bin, a granulator, a granulated slag collecting device and a fixed bracket, a slag inlet in the top of the granulation bin is formed in the center position, and a spray pipe and a material nozzle are sequentially arranged outwards; a visual explosion-proof membrane is arranged on the granulation bin; a pelletizer is arranged under the slag inlet in the pelletizing bin, the pelletizer is connected with a base through a bearing, the outer edge of the base is fixedly connected with a pelletized slag flow assisting sheet, the pelletizer is connected with a rotating shaft, and a motor drives the rotating shaft to drive the pelletizer to rotate; the baffle is of a conical structure, the baffle is connected with a plurality of metallurgical gas collecting pipes, the baffle is arranged below the granulated slag flow aiding pieces, and ports of the metallurgical gas collecting pipes are formed in the granulated slag collecting device. The granulation system has the advantages that the granulation system is a fully-closed system integrating granulation, gasification reaction and waste heat recovery, slag can be efficiently crushed, chemical recycling is achieved, and the controllability of the granulation process is improved.

Description

Technical Field

[0001] This invention belongs to the field of high-temperature slag granulation, and particularly relates to a material injection visualization hot molten slag granulation system and granulation method. Background Technology

[0002] In the metallurgical industry, blast furnace ironmaking generates a large amount of high-temperature molten slag (such as blast furnace slag and converter slag). The proper handling of this hot molten slag has always been a key issue affecting production efficiency, energy utilization, and environmental protection. The methods for handling hot molten slag directly impact resource utilization efficiency, ecological environment quality, and the improvement of production efficiency.

[0003] Taking traditional water quenching as an example, although it appears to be a mature technology and a widely used method for slag granulation, its drawbacks are also quite significant. Water quenching requires a large amount of water, and for every ton of slag processed, 50-100 mg / L of slag is released. 3 The release of sulfur-containing harmful gases is another issue. These unpurified gases, once released into the atmosphere, quickly integrate into the regional atmospheric cycle, becoming a major contributor to acid rain formation and causing incalculable damage to the surrounding ecological environment. The energy inefficiency of water quenching is also significant. A large amount of sensible heat contained in the slag is lost during water quenching as water vapor evaporates. According to precise calculations by energy experts, the sensible heat of the slag accounts for as much as 10% to 15% of the total energy consumption in steel production. If this heat energy could be effectively recovered and utilized, the energy efficiency of steel enterprises would be greatly improved, and energy conservation and emission reduction targets would be easier to achieve. As for mechanical granulation, although it represents an improvement over water quenching in terms of environmental protection, it still exposes many thorny problems in actual operation. On production lines using traditional mechanical granulation, 30% to 40% of the granulated slag particles fail to meet quality standards and must undergo secondary processing. This not only significantly increases production costs but also seriously affects production rhythm and efficiency.

[0004] In the prior art, patent application number CN201610900314.6 discloses a high-temperature liquid slag granulation system that uses high-pressure jet granulation technology to break up the slag with high-pressure water or gas. The equipment is simple, but it cannot handle harmful components in the slag, and the thermal energy is not effectively utilized. Patent application number CN201610141188.0 discloses a high-temperature liquid slag granulation system that uses centrifugal granulation combined with annular air cooling. It improves the glass fraction by combining rotating disk granulation with air cooling, but the open nature of the system leads to exhaust gas leakage, still posing a risk of environmental pollution.

[0005] The core challenge facing current slag treatment technology is how to achieve waste heat recovery, CO2 emission reduction, and resource recovery of harmful gases while efficiently granulating the slag. Existing technologies either focus on physical granulation while neglecting chemical reactions, or lack visual monitoring and modular design, resulting in poor system adaptability and maintenance difficulties. Therefore, there is an urgent need for a fully enclosed system that integrates granulation, gasification reaction, and waste heat recovery. This system should be able to efficiently crush slag using centrifugal force, achieve chemical resource recovery through the injection of materials (such as biomass and CO2), and improve process controllability through visual design. Summary of the Invention

[0006] To overcome the shortcomings of the existing technology, the purpose of this invention is to provide a material spraying visualization hot molten slag granulation system and granulation method, which solves the technical problem of energy reuse in the high-temperature liquid molten slag granulation process, optimizes the chemical reaction, contact area and heat exchange efficiency between materials, cooling medium and particles, and mineralizes and solidifies CO2 while ensuring efficient granulation of molten slag and generating reducing gas required in the metallurgical process, which facilitates subsequent waste heat recovery and reuse.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A material injection visualization hot molten slag granulation system includes a granulation bin, a granulator, a granulated molten slag collection device, and a fixed support;

[0009] The top of the granulation bin is equipped with a slag inlet, a material nozzle, and a spray pipe. The slag inlet is located in the center, and the spray pipe and material nozzle are arranged outward in sequence. The inner wall of the granulation bin is equipped with a water-cooled wall, and the granulation bin is equipped with a visual explosion-proof membrane.

[0010] A granulator is located directly below the slag inlet in the granulation chamber. The granulator is connected to the base via a bearing. The outer edge of the base is fixedly connected to the slag flow aid plate. The granulator is connected to a rotating shaft. A motor drives the rotating shaft to rotate, which in turn drives the granulator to rotate. The rotating shaft passes through a rotating shaft sleeve, and the rotating shaft and the rotating shaft sleeve are connected via a bearing. The rotating shaft sleeve is fixedly connected to a fixed bracket. The granulation chamber is mounted on the fixed bracket. The motor is mounted inside the fixed bracket.

[0011] The granulated slag collection device is located at the bottom of the granulation chamber. The granulated slag collection device includes a baffle, which is a conical structure. The bottom of the baffle is connected to the bottom of the granulation chamber and the fixed support. The baffle is connected to several metallurgical gas collection pipes. The baffle is located below the granulated slag flow aid plate. The port of the metallurgical gas collection pipe is located inside the granulated slag collection device.

[0012] The granulation chamber is connected to a granulation chamber cover at the top. From the center outwards, a slag inlet, a spray pipe, and a material nozzle are fixedly connected to the granulation chamber cover. Several spray pipes are evenly distributed radially. Several material nozzles are evenly distributed radially.

[0013] The nozzle and the material nozzle can be integrated into the same pipe.

[0014] It also includes transmission gears and a conveyor belt. There are two transmission gears, which are connected to the motor and the shaft respectively. The two transmission gears are connected by the conveyor belt.

[0015] The granulation chamber is cylindrical.

[0016] The granulation chamber is equipped with a visible explosion-proof membrane at the top and / or middle.

[0017] The granulated slag flow aid plate is a conical structure with space between its outer edge and the inner wall of the granulation chamber.

[0018] A method for visualizing the granulation of hot molten slag by material injection, comprising:

[0019] 1) Start the motor, the granulator rotates, and the high-temperature liquid slag flows into the granulation chamber from the slag inlet and falls directly onto the granulator. Through the interaction of the fluidity of the high-temperature slag and the centrifugal force of the granulator, splashing high-temperature slag droplets are generated.

[0020] 2) The material nozzle pressurizes and sprays biomass material into the granulation bin. The biomass material comes into contact with the high-temperature molten slag droplets splashed in the granulation bin and undergoes a gasification reaction, while heat exchange occurs at the same time. The metallurgical gas generated by the gasification reaction is discharged from the granulation bin through the metallurgical gas collection pipe for recycling.

[0021] 3) The granulated slag after the reaction is introduced into the granulated slag collection device by the flow aid plate. In the granulated slag collection device, CO2 is sprayed into the granulation chamber by the nozzle. CO2 reacts with the granulated slag and exchanges heat at the same time. The gas after heat exchange is discharged from the granulation chamber through the metallurgical gas collection pipe, and the waste heat is recovered and reused.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. The granulation system of the present invention is a fully enclosed system that integrates granulation, gasification reaction and waste heat recovery. It can efficiently crush slag through centrifugal force and realize chemical resource utilization by blowing materials (such as biomass and CO2). At the same time, it improves the controllability of the granulation process with the help of visual design.

[0024] 2. This invention utilizes the interaction between the centrifugal force of the rotating granulator and the fluidity of the high-temperature molten slag to form fine droplets that splash out, resulting in more complete granulation of the molten slag. The granulated slag has a uniform particle size, which is beneficial for subsequent processing and application.

[0025] 3. The granulation chamber is equipped with a visual explosion-proof membrane, allowing operators to observe the granulation behavior of the molten slag within the chamber in real time. This enables operators to monitor various aspects of the granulation process, such as the degree of molten slag droplet splashing and the operating status of the granulator. If any abnormalities are detected, such as excessively large granulated droplets or granulator malfunction, operating parameters can be adjusted promptly, such as adjusting the granulator speed and molten slag flow rate, thereby optimizing the granulation process and improving granulation efficiency.

[0026] 4. The gas after heat exchange is further recycled and reused through a metallurgical gas collection pipe. In the granulated slag collection device, the heat of the gas produced after CO2 reacts with the granulated slag and exchanges heat is collected, improving the energy utilization efficiency of the entire system and reducing production costs. Simultaneously, pressurized biomass and CO2 gas are injected into the granulation chamber to maintain a slight positive pressure, preventing external gases from entering while the biomass gasification reaction and the mineralization and solidification of CO2 reaction proceed.

[0027] 5. This invention solves the technical problem of energy reuse in the high-temperature liquid slag granulation process. It utilizes the granulation process of high-temperature slag transforming into medium-temperature slag and the heat generated in the process to replace the biomass gasification process and the heat consumption used in the process. It utilizes low-temperature slag mineralization to solidify CO2, consumes the CO2 surplus generated in other processes, and the gas after reaction heat exchange is used for subsequent waste heat recovery and reuse through a metallurgical gas collection pipe. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 This is a top view of the interior of the granulation chamber.

[0030] Figure 3 This is a schematic diagram of the granulation chamber cover.

[0031] Figure 4 This is a schematic diagram of the granulation chamber.

[0032] Figure 5 This is a schematic diagram of the granulator connection.

[0033] In the diagram: 1-Slag inlet; 2-Material nozzle and spray pipe; 3-Visual explosion-proof membrane; 4-Granulation bin cover; 5-Granulation bin; 6-Granulation slag flow aid plate; 7-Granulator; 8-Fixed bracket; 9-Baffle; 10-Spindle sleeve; 11-Collection bin; 12-Metallurgical gas collection pipe; 13-Spindle; 14-Motor; 15-Conveyor belt. Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0035] See Figures 1-5 A visualized hot molten slag granulation system includes a granulation bin 5, a granulator 7, a granulated molten slag collection device, and a fixed support 8. The top of the granulation bin 5 is equipped with a molten slag inlet 1, a spray pipe 2, and a material nozzle 2. The molten slag inlet 1 is located at the center, with the spray pipe 2 and material nozzle 2 arranged outwards. The inner wall of the granulation bin 5 is equipped with a water-cooled wall, through which cooling water exchanges heat with the steel slag during the granulation process, further cooling the residual heat of the granulated steel slag to bring it to room temperature. The heated cooling water is then recovered and reused for waste heat. The water-cooled wall is used to further cool the residual heat of the granulated steel slag to bring it to room temperature. The water-cooled wall can be located in the middle of the granulation bin 5 wall, using water circulation to remove the heat transferred to the granulation bin 5 by the high-temperature steel slag through heat transfer or radiation, allowing the granulation bin 5 to be used for a long time. A visualized explosion-proof membrane 3 is provided at the top and / or middle of the granulation bin 5. The visual explosion-proof membrane 3 can be embedded in the wall of the granulation chamber 5 or in the granulation chamber cover 4. The visual explosion-proof membrane 3 is set between the granulation slag flow aid plate 6 and the baffle 9. The nozzle 2 and the material nozzle 2 can be integrated into the same pipeline.

[0036] The granulation chamber 5 is cylindrical. A granulator 7 is located directly below the slag inlet 1 inside the granulation chamber 5. The granulator 7 is connected to the base via bearings. The outer edge of the base is fixedly connected to the granulation slag flow aid 6. The angle between the granulation slag flow aid 6 and the horizontal plane is 15°–45°, and the granulation slag flow aid 6 tilts upwards from the outer edge of the base towards the inner wall of the granulation chamber 5. The granulation slag flow aid 6 is made of steel plate and has an overall conical structure, with space between its outer edge and the inner wall of the granulation chamber 5. The granulator 7 is connected to a rotating shaft 13. A motor 14 drives the rotating shaft 13 to rotate, thereby driving the granulator 7 to rotate. The rotating shaft 13 passes through a rotating shaft 13 sleeve 10, and the rotating shaft 13 and the rotating shaft 13 sleeve 10 are connected via bearings. The rotating shaft 13 sleeve 10 is fixedly connected to a fixed support 8. The granulation chamber 5 is mounted on the fixed support 8. The motor 14 is mounted inside the fixed support 8.

[0037] A granulated slag collection device is located at the bottom of the granulation chamber 5. The device includes a baffle 9, which is conical in shape. The bottom of the baffle 9 is connected to the bottom of the granulation chamber 5 and a fixed support 8. The bottom of the baffle 9 is open, and a collection chamber 11 is connected below it to collect the granulated steel slag discharged from the baffle 9. Alternatively, the bottom of the baffle 9 can be closed with an opening. A conveyor belt is installed below the opening to transport the granulated steel slag out. The baffle 9 is connected to several metallurgical gas collection pipes 12. The ports of the metallurgical gas collection pipes 12 are located inside the granulation slag collection device. These pipes collect the gas generated inside the granulation chamber 5 and discharge it outside.

[0038] For ease of maintenance and installation, a granulation chamber cover 4 is connected to the top of the granulation chamber 5. From the center outwards, a slag inlet 1, a nozzle 2, and a material nozzle 2 are fixedly connected to the granulation chamber cover 4. Several nozzles 2 are evenly distributed radially; several material nozzles 2 are also evenly distributed radially. The slag inlet 1 ensures the free fall of liquid slag; the material nozzles 2 are used to spray biomass materials into the granulated slag for gasification reaction.

[0039] The material blowing visualization hot molten slag granulation system also includes transmission gears and a conveyor belt 15. There are two transmission gears, which are connected to the motor 14 and the rotating shaft 13 respectively. The two transmission gears are connected by the conveyor belt 15.

[0040] All joints in the granulation system requiring sealing utilize castable refractory, fire-resistant fiber, or mechanical seals. Examples include: the connection between granulation bin 5 and granulation bin cover 4; the connections between slag inlet 1, nozzle 2, material nozzle 2 and granulation bin cover 4; the connection of the visible explosion-proof membrane 3; and the connection between baffle 9 and bin body. Mechanical sealing methods include: flange connection between bin cover and granulation bin 5; threaded connection between liquid slag inflow pipe, gas collecting pipe, and material nozzle and bin cover; and high-temperature cement bonding or welding between the visible explosion-proof membrane 3 and bin body / cover. All surfaces of materials exposed to high temperatures are coated with anti-oxidation paint for oxidation prevention.

[0041] The granulator 7 can be a disc-shaped granulator 7, such as: Patent Publication No. CN106868238A, which discloses a granulator 7 system for granulating liquid slag; Patent Publication No. CN108411053A, which discloses a liquid slag granulation equipment and driving device with lifting function. An annular granulator 7 can also be used.

[0042] See Figures 1-5 A method for visualizing the granulation of hot molten slag by material injection, comprising:

[0043] 1) Start motor 14, granulator 7 rotates, high temperature liquid slag flows from slag inlet 1 into granulation chamber 5, falls directly onto granulator 7, and through the interaction of the fluidity of high temperature slag and centrifugal force of granulator 7, splashing high temperature slag droplets are generated.

[0044] 2) The material nozzle 2 pressurizes and sprays biomass material into the granulation bin 5. The biomass material comes into contact with the high-temperature molten slag droplets splashed in the granulation bin 5 and undergoes a gasification reaction, while heat exchange occurs at the same time. The metallurgical gas generated by the gasification reaction is discharged from the granulation bin 5 through the metallurgical gas collection pipe 12 for recycling. The biomass material is one or more of waste wood chips, bamboo chips, rice husks, and crop straw.

[0045] 3) The granulated slag after the reaction is introduced into the granulated slag collection device by the flow aid plate 6. In the granulated slag collection device, CO2 is sprayed upwards into the granulation chamber 5 through the nozzle 2. The CO2 reacts with the granulated slag and exchanges heat simultaneously. The gas after heat exchange is discharged from the granulation chamber 5 through the metallurgical gas collection pipe 12, and the waste heat is recovered and reused. The CO2 sprayed by the nozzle 2 makes the pressure in the granulation chamber 5 slightly higher than atmospheric pressure (the pressure in the granulation chamber 5 is less than or equal to 0.2 MPa), so that the gas reacting in the granulation chamber 5 can be forced outwards due to the high pressure.

[0046] Furthermore, by setting up a visual explosion-proof membrane 3, the state of the molten slag at different stages during the granulation process can be observed, capturing the process of high-temperature slag granulation from unstable to stable, liquid film spreading, liquid ring detachment, liquid finger formation, and liquid filament breakage. The CO2 injection source can be blast furnace gas, coke oven gas, or converter gas, all of which contain CO2.

Claims

1. A material injection visualization system for hot molten slag granulation, characterized in that, Includes granulation bin, granulator, granulation slag collection device, and fixed support; The top of the granulation bin is equipped with a slag inlet, a material nozzle, and a spray pipe. The slag inlet is located in the center, and the spray pipe and material nozzle are arranged outward in sequence. The inner wall of the granulation bin is equipped with a water-cooled wall, and the granulation bin is equipped with a visual explosion-proof membrane. A granulator is located directly below the slag inlet in the granulation chamber. The granulator is connected to the base via a bearing. The outer edge of the base is fixedly connected to the slag flow aid plate. The granulator is connected to a rotating shaft. A motor drives the rotating shaft to rotate, which in turn drives the granulator to rotate. The rotating shaft passes through a rotating shaft sleeve, and the rotating shaft and the rotating shaft sleeve are connected via a bearing. The rotating shaft sleeve is fixedly connected to a fixed bracket. The granulation chamber is mounted on the fixed bracket. The motor is mounted inside the fixed bracket. The granulated slag collection device is located at the bottom of the granulation chamber. The granulated slag collection device includes a baffle, which is a conical structure. The bottom of the baffle is connected to the bottom of the granulation chamber and the fixed support. The baffle is connected to several metallurgical gas collection pipes. The baffle is located below the granulated slag flow aid plate. The port of the metallurgical gas collection pipe is located inside the granulated slag collection device.

2. The material injection visualization hot molten slag granulation system according to claim 1, characterized in that, The granulation chamber is connected to a granulation chamber cover at the top. From the center outwards, a slag inlet, a spray pipe, and a material nozzle are fixedly connected to the granulation chamber cover. Several spray pipes are evenly distributed radially. Several material nozzles are evenly distributed radially.

3. The material injection visualization hot molten slag granulation system according to claim 1, characterized in that, The nozzle and the material nozzle are integrated into the same pipe.

4. The material injection visualization hot molten slag granulation system according to claim 1, characterized in that, It also includes transmission gears and a conveyor belt. There are two transmission gears, which are connected to the motor and the shaft respectively. The two transmission gears are connected by the conveyor belt.

5. The material injection visualization hot molten slag granulation system according to claim 1, characterized in that, The granulation chamber is cylindrical.

6. The material injection visualization hot molten slag granulation system according to claim 1, characterized in that, The granulation chamber is equipped with a visible explosion-proof membrane at the top and / or middle.

7. The material injection visualization hot molten slag granulation system according to claim 1, characterized in that, The granulated slag flow aid plate is a conical structure with space between its outer edge and the inner wall of the granulation chamber.

8. A method for visualizing hot molten slag granulation by material injection using a granulation system according to any one of claims 1-7, characterized in that, include: 1) Start the motor, the granulator rotates, and the high-temperature liquid slag flows into the granulation chamber from the slag inlet and falls directly onto the granulator. Through the interaction of the fluidity of the high-temperature slag and the centrifugal force of the granulator, splashing high-temperature slag droplets are generated. 2) The material nozzle pressurizes and sprays biomass material into the granulation bin. The biomass material comes into contact with the high-temperature molten slag droplets splashed in the granulation bin and undergoes a gasification reaction, while heat exchange occurs at the same time. The metallurgical gas generated by the gasification reaction is discharged from the granulation bin through the metallurgical gas collection pipe for recycling. 3) The granulated slag after the reaction is introduced into the granulated slag collection device by the flow aid plate. In the granulated slag collection device, CO2 is sprayed into the granulation chamber by the nozzle. CO2 reacts with the granulated slag and exchanges heat at the same time. The gas after heat exchange is discharged from the granulation chamber through the metallurgical gas collection pipe, and the waste heat is recovered and reused.

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