Blast furnace slag roller-type quenching treatment system

Abstract

The utility model provides a blast furnace molten slag drum -type cold quenching treatment system, it includes: preprocessing unit, preprocessing unit is connected with the molten slag export of blast furnace and is used for the slow -moving cache of molten slag, temperature control and flow control processing, dry -type cold quenching treatment unit, dry -type cold quenching treatment unit is connected with preprocessing unit to receive the molten slag with predetermined temperature and predetermined flow, dry -type cold quenching treatment unit has the slag groove and is established at the slag groove above the drum, forms the heat exchange cooling chamber in the drum and is connected with the heat exchange circulating loop that communicates with heat exchange cooling chamber, and the scraping device for scraping high -temperature slag piece is established at one side of the drum, post -treatment unit, post -treatment unit is connected with dry -type cold quenching treatment unit to receive high -temperature slag piece, and post -treatment unit is used for the whole particle and cooling treatment of slag piece. The utility model can solve the problem that the blast furnace molten slag dry -type processing technology exists granulation equipment life shorter, product quality quality control difficulty high, heat recovery efficiency low.

Description

Technical Field

[0001] This utility model relates to the field of iron and steel smelting technology, and in particular to a blast furnace slag drum-type cold quenching system. Background Technology

[0002] High-temperature molten slag is a major byproduct of blast furnace smelting, possessing extremely high value for solid waste resource reuse and economic benefits. The discharge temperature of high-temperature molten slag reaches as high as 1450℃, containing a large amount of high-temperature waste heat (approximately 60 kg of standard coal / ton of slag).

[0003] Currently, the mature technology for treating blast furnace slag involves water quenching and rapid cooling to form slag with a high glass content. Its potential hydration activity makes it suitable for use in cementitious admixtures and concrete additives, finding wide application in the building materials field. However, this technology suffers from problems such as low slag heat recovery rate (≤10%), significant water waste, and environmental pollution. With the increasing emphasis on energy conservation and emission reduction, and the need for green and environmentally friendly steel enterprise construction, the adoption of new technologies to achieve efficient waste heat recovery from high-temperature liquid slag and the resource utilization of its products, while simultaneously addressing environmental pollution and water waste, has become an urgent priority.

[0004] Dry treatment of blast furnace slag has significant potential advantages in reducing water consumption and slag preheating and recovery. However, due to the characteristics of blast furnace slag, such as high temperature, complex composition, large changes in physical properties, discontinuous slag discharge, large fluctuations in slag flow during the slag discharge process, and low thermal conductivity, the dry treatment technology of blast furnace slag still faces bottlenecks such as short lifespan of granulation equipment, high difficulty in product quality control, and low heat recovery efficiency, which urgently need to be solved.

[0005] Although the dry quenching process of blast furnace slag has been studied since the 1980s, and there are several main processes, they have not achieved mature industrial application due to their respective reasons.

[0006] (1) Cooling drum method:

[0007] The molten slag is guided by the slag channel and flows into a pair of cooling drums. The drums rotate continuously, and the high-boiling-point organic coolant (alkyl biphenyl) absorbs heat from the thin film inside the drum. When the liquid molten slag comes into contact with the surface of the drum, a thin film (1000~1100℃) is formed on it. After the slag is cooled, it is scraped off by the scraper and collected in the hopper. It is further cooled to 250℃ by cold air. After absorbing heat, the organic coolant flows out from the drum outlet and enters the heat exchanger to be cooled again. Then, under the action of the pump, it flows back into the drum for secondary recovery. The recovered heat can be used for heating or steam power generation.

[0008] The above methods have low reliability because the thin flakes produced during production can easily cause drum jamming. The instantaneous flow fluctuation of molten slag and the uncertainty of drum rotation make it impossible to accurately control the thickness of the molten slag flakes, resulting in unstable quality of the final slag product. Furthermore, it is difficult to develop coolants with high boiling points and high thermal conductivity, which affects the quality of the slag product. The low heat recovery efficiency and lifespan have prevented industrial promotion to date.

[0009] (2) Mechanical stirring method:

[0010] The molten slag continuously enters the stirring granulation device, where it is broken up and cooled by the rotational force of the blades. The cooled slag particles are then discharged under the propulsion of the rotational force, with a temperature of approximately 900°C. To further recover the residual heat of the molten slag, the heat contained in the discharged slag particles is further recovered and utilized. The slag particles obtained by this method have a relatively large diameter, mostly around 20 mm, and contain almost no glassy particles. These slag particles are typically used as paving materials.

[0011] This method results in slow cooling of the slag particles, inefficient heat recovery, and subsequent products that cannot generate high value, thus lacking the conditions for market promotion.

[0012] (3) Air quenching method:

[0013] The molten slag discharged from the blast furnace is introduced into a specially designed wind tunnel for granulation. The slag is atomized by a high-speed airflow. The slag particles hit the dispersion plates and inner walls arranged in the wind tunnel and fall down. At this time, the temperature of the slag particles drops to about 1050°C. During the fall, they are cooled by the air blown in from the bottom of the wind tunnel, and the temperature when they exit the wind tunnel is about 800°C. After the discharged slag particles are screened by a vibrating screen to remove large-diameter particles, they are stored in a hot slag particle storage bin and cooled to about 150°C through a multi-stage fluidized bed for secondary heat exchange before being discharged.

[0014] This process has a high air-to-slag ratio, high fan energy consumption, and high operating costs, which may result in the value of recovered heat being lower than the input cost. In addition, the designed equipment occupies a large area.

[0015] (4) Centrifugal granulation method:

[0016] Centrifugal granulation utilizes the centrifugal force generated by a high-speed rotating cup / disc / drum to spread the slag-liquid mixture into a liquid film, which further extends and forms filaments, eventually breaking down to achieve granulation. A waste heat recovery system is then used to recover and utilize the sensible heat of the small solid particles.

[0017] The above methods have problems such as slag crusting, uneven granulated slag particle size, and slag wool generation, which need to be further studied and improved. The refractory material of the granulation disc is easily eroded by molten slag. The uneven surface will lead to uneven distribution of molten slag on the disc surface and uneven thickness of the liquid film. This may result in large fluctuations in the particle size of the granulated slag particles, or even failure to granulate. Slag wool is easily generated during the rotation process, which makes it difficult to recover the waste heat of the subsequent solid particles. Utility Model Content

[0018] The purpose of this invention is to provide a drum-type cold quenching system for blast furnace slag, which solves the problems of short lifespan of granulation equipment, high difficulty in product quality control, and low heat recovery efficiency in the current dry blast furnace slag treatment technology.

[0019] The above-mentioned technical objectives of this utility model are mainly achieved through the following technical solutions.

[0020] This utility model provides a blast furnace slag drum-type cold quenching system, which includes:

[0021] A pretreatment unit is connected to the slag outlet of the blast furnace and is used to buffer, control the temperature and flow of the slag.

[0022] A dry quenching unit is connected to the pretreatment unit to receive molten slag with a predetermined temperature and a predetermined flow rate. The dry quenching unit has a slag tank and a drum disposed above the slag tank. A heat exchange cooling chamber is formed inside the drum and a heat exchange circulation loop connected to the heat exchange cooling chamber is provided. A scraping device for scraping high-temperature slag flakes is provided on one side of the drum.

[0023] A post-processing unit is connected to the dry quenching unit to receive the high-temperature slag flakes, and the post-processing unit is used to granulate and cool the slag flakes.

[0024] In a preferred embodiment of this utility model, the roller is mounted on a lifting bracket, and the roller can move up and down under the drive of the lifting bracket to separate from or contact the molten slag in the slag tank.

[0025] In a preferred embodiment of this utility model, a steam generator and a driving device are provided on the heat exchange circulation loop, and the steam generator is connected to a heat exchange water pipe.

[0026] In a preferred embodiment of this invention, the heat exchange medium circulating in the heat exchange loop is a liquid alloy.

[0027] In a preferred embodiment of the present invention, the slag trough is configured to move left and right relative to the drum.

[0028] In a preferred embodiment of the present invention, the dry quenching unit further includes a dust removal hood, which is disposed above the slag tank to cover the roller.

[0029] In a preferred embodiment of the present invention, the dust removal hood is configured to move left and right relative to the slag trough.

[0030] In a preferred embodiment of the present invention, the dust removal hood is provided with a heat insulation layer; and / or, the dust removal hood is provided with a liquid level detector for monitoring the liquid level of the molten slag in the slag tank; and / or, the dust removal hood is provided with a temperature detector for monitoring the temperature of the molten slag in the slag tank.

[0031] In a preferred embodiment of the present invention, the pretreatment unit has a buffer tank, an electric heating device is provided in the buffer tank, and an outlet flow control device is provided at the outlet of the buffer tank to control the flow rate of the molten slag to the slag tank.

[0032] In a preferred embodiment of the present invention, the post-processing unit comprises a crushing device, a high-temperature conveying device, a high-temperature solid slag particle cooling device, and a low-temperature conveying device connected in sequence, wherein the high-temperature solid slag particle cooling device is connected to a cooling water pipe.

[0033] Compared with the prior art, the technical solution of this utility model has the following features and advantages:

[0034] The blast furnace slag drum-type cold quenching system described in this utility model treats blast furnace slag through a pretreatment unit, which buffers, controls the temperature and flow, transforming the unstable slag flow rate into a stable and controllable flow rate. Then, the slag is rapidly cooled into solid slag flakes through a dry cold quenching unit. After further granulation and cooling in the post-treatment unit, dry slag particles with a high glass transition rate are produced. This system can efficiently recover the heat from the high-temperature liquid slag and generate high-value saturated steam. Compared with existing water quenching processes, it can significantly reduce water consumption per ton of slag, avoid the emission of sulfides in water quenching processes, and generate high-value steam, bringing considerable profits to enterprises. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0036] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, under the guidance of this invention, can select various possible shapes and proportions to implement this invention according to specific circumstances.

[0037] Figure 1 This is a schematic diagram of the blast furnace slag drum-type cold quenching system described in this utility model.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100. Pre-processing unit; 101. Buffer tank; 102. Electric heating device; 103. Outlet flow control device;

[0040] 200. Dry quenching unit; 201. Slag tank; 202. Drum; 203. Lifting support; 204. Heat exchange circulation loop; 205. Steam generator; 206. Drive unit; 207. Scraping device; 208. Hot water pipe; 209. Dust hood; 210. Dust hood support;

[0041] 300. Post-processing unit; 301. Crushing device; 302. High-temperature conveying device; 303. High-temperature solid slag particle cooling device; 304. Low-temperature conveying device; 305. Cooling water pipe;

[0042] 400. Blast furnace. Detailed Implementation

[0043] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0044] 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.

[0045] 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 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.

[0046] This utility model provides a drum-type cold quenching system for blast furnace slag, such as... Figure 1 As shown, it includes: a pretreatment unit 100, which is connected to the slag outlet of the blast furnace 400 and is used for buffering, temperature control, and flow control of the slag; a dry quenching unit 200, which is connected to the pretreatment unit 100 to receive slag with a predetermined temperature and a predetermined flow rate, the dry quenching unit 200 having a slag trough 201 and a drum 202 disposed above the slag trough 201, a heat exchange cooling chamber being formed inside the drum 202 and a heat exchange circulation loop 204 connected to the heat exchange cooling chamber, and a scraping device 207 for scraping high-temperature slag flakes being provided on one side of the drum 202; and a post-treatment unit 300, which is connected to the dry quenching unit 200 to receive high-temperature slag flakes, and the post-treatment unit 300 is used for granulation and cooling of the slag flakes.

[0047] The blast furnace slag drum-type cold quenching system of this utility model treats the blast furnace 400 molten slag through the buffering, temperature control and flow control of the pretreatment unit 100, transforming the unstable molten slag flow of the blast furnace 400 into a stable and controllable molten slag flow. Then, the molten slag is rapidly cooled into solid slag flakes through the dry cold quenching treatment unit 200. After granulation and cooling treatment by the post-treatment unit 300, dry slag particles with high glass transition rate are produced. This system can efficiently recover the heat of high-temperature liquid molten slag and generate high-value saturated steam. Compared with the existing water quenching process, it can significantly reduce the water consumption per ton of slag and avoid the emission of sulfides in the water quenching process.

[0048] The following will describe in detail the specific structure of each part of the blast furnace slag drum-type cold quenching system described in this utility model, as well as the position and connection relationship between each part.

[0049] like Figure 1 As shown, the blast furnace slag drum-type cold quenching system includes a pretreatment unit 100, a dry cold quenching unit 200, and a post-treatment unit 300 connected in sequence.

[0050] The pretreatment unit 100 is connected to the blast furnace 400. The high-temperature liquid slag produced by the blast furnace 400 enters the pretreatment unit 100. The pretreatment unit 100 is used to buffer, control the temperature and flow of the high-temperature liquid slag.

[0051] Specifically, such as Figure 1 As shown, the pretreatment unit 100 has a buffer tank 101, the inlet of which is connected to the slag outlet of the blast furnace 400 via a pipe. An electric heating device 102 is installed inside the buffer tank 101 to ensure the fluidity of the high-temperature liquid slag; the electric heating device 102 can be a resistance wire. An outlet flow control device 103 is installed at the outlet of the buffer tank 101 to control the flow rate of the high-temperature liquid slag towards the slag bin 201, thereby achieving flow control; the outlet flow control device 103 can be an electrically controlled valve or other flow control structure, which is not specifically limited here.

[0052] The pretreatment unit 100 receives the high-temperature liquid slag generated by the blast furnace 400 cycle. Through buffering, temperature control and flow control, the unstable slag flow rate of the blast furnace 400 is transformed into a stable and controllable slag flow rate, thereby ensuring the stability of the subsequent processing.

[0053] The dry quenching unit 200 is connected to the pretreatment unit 100. The high-temperature liquid slag with a predetermined temperature and flow rate flowing out of the pretreatment unit 100 enters the dry quenching unit 200. The dry quenching unit 200 rapidly cools the high-temperature liquid slag into solid slag through a dry drum quenching process.

[0054] Specifically, such as Figure 1 As shown, the dry quenching unit 200 has a slag tank 201 and a drum 202 positioned above the slag tank 201. The slag tank 201 receives the high-temperature liquid slag flowing out of the pretreatment unit 100 and provides conditions for the drum 202 to operate. The slag tank 201 is made of corrosion-resistant and heat-insulating material. The drum 202 is mounted on a lifting support 203 and can move up and down under the drive of the lifting support 203 to separate from or contact the slag in the slag tank 201. A heat exchange cooling chamber is formed inside the drum 202 and connected to a heat exchange circulation loop 204 that communicates with the heat exchange cooling chamber. The heat exchange circulation loop 204 is equipped with a steam generator 205 and a drive device 206 (liquid alloy circulation pump). The steam generator 205 is connected to a heat exchange water pipe 208. The heat exchange medium circulating in the heat exchange loop 204 is a liquid alloy. This liquid alloy has high thermal conductivity, enabling rapid cooling of the molten slag adhering to the outer wall of the drum 202 during rotation, thus forming slag flakes with a high glass transition rate. The drum 202 is used to rapidly cool the molten slag into solid slag. The side wall of the drum 202 is cooled by circulating liquid alloy, which rapidly cools the high-temperature liquid slag into solid slag during rotation and heats the low-temperature liquid alloy to a high temperature. A scraping device 207, which is a scraper that contacts the side wall of the drum 202, is provided on one side of the drum 202 to scrape off the high-temperature slag flakes.

[0055] Preferably, the slag trough 201 is movable for easy replacement; in this embodiment, the bottom of the slag trough 201 is provided with rollers.

[0056] The specific workflow of the dry quenching unit 200 is as follows:

[0057] After the high-temperature liquid slag in the slag tank 201 reaches the set height, the heat exchange circulation loop 204 is started, so that the liquid alloy circulates between the drum 202 and the steam generator 205. The drum 202 rotates under the drive of the end motor and descends through the lifting bracket 203. The lower part of the drum 202 is partially immersed in the high-temperature liquid slag. When the drum 202 rotates, it quickly cools the slag and sticks it to the surface of the drum 202 to form a relatively uniform solid slag sheet. The solid slag sheet is peeled off by the scraper on one side of the drum 202 and enters the next process. The cryogenic liquid alloy flows into the heat exchange and cooling chamber inside the drum 202 through one end. The heat from the high-temperature liquid slag is transferred to the cryogenic liquid alloy through the metal outer wall of the drum 202. After gaining heat, the temperature of the cryogenic liquid alloy rises. The heated high-temperature liquid alloy flows out from the other end of the drum 202. The high-temperature liquid alloy is heated by the steam generator 205 to generate high-pressure steam in the heat exchange water pipe 208. The cooled cryogenic liquid alloy returns to the drum 202 through the liquid alloy circulation pump to achieve cooling circulation.

[0058] The post-processing unit 300 is connected to the dry quenching unit 200. The high-temperature slag produced by the dry quenching unit 200 enters the post-processing unit 300, which is used to crush and cool the high-temperature slag.

[0059] Specifically, such as Figure 1 As shown, the post-processing unit 300 has a crushing device 301, a high-temperature conveying device 302, a high-temperature solid slag particle cooling device 303, and a low-temperature conveying device 304 connected in sequence. The high-temperature solid slag particle cooling device 303 is connected to a cooling water pipe 305. The crushing device 301 can be a double-roll crusher, the high-temperature conveying device 302 and the low-temperature conveying device 304 can both be belt conveyors, and the high-temperature solid slag particle cooling device 303 can be a solid-liquid heat exchanger.

[0060] High-temperature liquid slag is rapidly cooled by drum 202 to produce high-temperature solid slag flakes with a temperature of approximately 600°C. After being peeled off, the slag flakes enter crushing device 301 to be crushed into high-temperature slag particles with a particle diameter of approximately 5 mm. Driven by high-temperature conveying device 302, the high-temperature slag particles enter high-temperature solid slag particle cooling device 303. In the high-temperature solid slag particle cooling device 303, the high-temperature slag particles are cooled to a temperature convenient for transportation (e.g., below 100°C) by indirect cooling. At the same time, the low-temperature water in cooling water pipe 305 is heated into hot water or steam. The cooled low-temperature slag particles are transported to a designated site through low-temperature conveying device 304 and used as slag powder or roadbed aggregate.

[0061] According to one embodiment of the present invention, such as Figure 1 As shown, the dry quenching unit 200 also includes a dust hood 209, which is placed above the slag tank 201 to cover the roller 202.

[0062] Specifically, the top of the dust collector 209 is mounted on the dust collector hood bracket 210 via rollers, and the dust collector 209 can move left and right relative to the slag tank 201. The dust collector 209 is used to collect high-temperature flue gas dust above the slag tank 201; the insulation layer on the dust collector 209 has a heat insulation function to reduce the heat loss of molten slag in the slag tank 201.

[0063] The dust hood 209 has a liquid level detection function. A liquid level detector is installed above the dust hood 209, which can provide real-time feedback on the liquid level of the molten slag in the slag tank 201 and is linked with the height of the drum 202, so that the immersion depth of the dry quenching drum 202 is stable and controllable, ensuring the quality stability of the dry slag sheets quenched by the drum 202.

[0064] The dust collector hood 209 has a temperature detection function. A temperature detector is installed above the dust collector hood 209, which can provide real-time feedback on the temperature of the molten slag in the slag tank 201. It is linked with the drum 202 to adjust process parameters such as the rotation speed of the drum 202, the flow rate of the liquid alloy, and the temperature of the liquid alloy according to the temperature, so as to ensure the quality stability of the cold-quenched dry slag sheets in the drum 202.

[0065] The dust collector hood 209 is equipped with an observation window and an operating door. The molten slag in the slag tank 201 can be observed through the openable observation window, and the operator can handle problems in the slag tank 201 through the openable operating door.

[0066] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above descriptions are merely specific embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A drum-type cold quenching system for blast furnace slag, characterized in that, include: A pretreatment unit (100) is connected to the slag outlet of the blast furnace (400) and is used to buffer, control the temperature and flow of the slag. A dry quenching unit (200) is connected to the pretreatment unit (100) to receive molten slag with a predetermined temperature and a predetermined flow rate. The dry quenching unit (200) has a slag tank (201) and a drum (202) disposed above the slag tank (201). A heat exchange cooling chamber is formed inside the drum (202) and a heat exchange circulation loop (204) connected to the heat exchange cooling chamber is provided. A scraping device (207) for scraping high-temperature slag flakes is provided on one side of the drum (202). A post-processing unit (300) is connected to the dry quenching unit (200) to receive the high-temperature slag flakes. The post-processing unit (300) is used to granulate and cool the slag flakes.

2. The blast furnace slag drum-type cold quenching system according to claim 1, characterized in that, The roller (202) is mounted on the lifting bracket (203). The roller (202) can move up and down under the drive of the lifting bracket (203) to separate from or contact the molten slag in the slag tank (201).

3. The blast furnace slag drum-type cold quenching system according to claim 1 or 2, characterized in that, The heat exchange circulation loop (204) is equipped with a steam generator (205) and a drive device (206), and the steam generator (205) is connected to a heat exchange water pipe (208).

4. The blast furnace slag drum-type cold quenching system according to claim 3, characterized in that, The heat exchange medium circulating in the heat exchange loop (204) is a liquid alloy.

5. The blast furnace slag drum-type cold quenching system according to claim 1 or 2, characterized in that, The slag trough (201) is configured to move left and right relative to the drum (202).

6. The blast furnace slag drum-type cold quenching system according to claim 1, characterized in that, The dry quenching unit (200) also includes a dust hood (209), which is positioned above the slag tank (201) to cover the roller (202).

7. The blast furnace slag drum-type cold quenching system according to claim 6, characterized in that, The dust hood (209) is configured to move left and right relative to the slag trough (201).

8. The blast furnace slag drum-type cold quenching system according to claim 6, characterized in that, The dust removal hood (209) is provided with a heat insulation layer; and / or, the dust removal hood (209) is provided with a liquid level detector for monitoring the liquid level of the molten slag in the slag tank (201); and / or, the dust removal hood (209) is provided with a temperature detector for monitoring the temperature of the molten slag in the slag tank (201).

9. The blast furnace slag drum-type cold quenching system according to claim 1, characterized in that, The pretreatment unit (100) has a buffer tank (101), an electric heating device (102) is provided in the buffer tank (101), and an outlet flow control device (103) is provided at the outlet of the buffer tank (101) to control the flow rate of the molten slag to the slag tank (201).

10. The blast furnace slag drum-type cold quenching system according to claim 1 or 9, characterized in that, The post-processing unit (300) has a crushing device (301), a high-temperature conveying device (302), a high-temperature solid slag particle cooling device (303) and a low-temperature conveying device (304) connected in sequence. The high-temperature solid slag particle cooling device (303) is connected to a cooling water pipe (305).

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