A method for determining the exhaust volume of a dust removal cover of a mobile ladle turret

Abstract

The application discloses a method for determining the exhaust capacity of a dust removal cover of a mobile steel ladle rotary table, wherein the dust removal cover is arranged above the steel ladle rotary table, and the exhaust capacity Q of the dust removal cover is Q=V g +3600*B*L*υ, wherein υ is the suction speed of air on the projection area of the dust removal cover, B is the cross-sectional width of the dust removal cover, L is the cross-sectional length of the dust removal cover, and V g is the volume flow rate of air replaced by molten steel filled into the tundish during pouring. The method can quantitatively determine the exhaust capacity standard of the dust removal cover, maximally control emission, minimize air flow requirements, minimize pressure loss energy, maximally reduce the influence on process efficiency and staff productivity, ensure that there is no obvious smoke and dust overflow in the whole production process, ensure that there is no visible smoke and dust overflow in the production process, and greatly improve the working environment of a pouring platform.

Description

Technical Field

[0001] This invention relates to the field of metallurgical equipment technology, specifically to a method for determining the exhaust volume of a dust collector hood on a mobile ladle rotary table. Background Technology

[0002] Environmental protection has increasingly become a hot topic of concern. In recent years, the state has further strengthened the control of air pollution from the metallurgical industry. Dust-generating points such as blast furnaces, molten steel pretreatment facilities, converters, electric furnaces, refining furnaces, lime kilns, and dolomite kilns should comprehensively strengthen their gas collection capabilities to ensure that no visible smoke or dust escapes, to ensure stable compliance with national or local air pollutant emission standards, to prevent air pollution, to meet the requirements of process production and human health, and to improve the working environment for production workers in the industry. Therefore, the efficient capture and purification of dust-laden flue gas has become an effective environmental protection measure.

[0003] The ladle turret is the most widely used ladle support and transport equipment in modern continuous casting. It is typically located between the steel receiving span and the pouring span columns, and has functions such as rotation, lifting, steel weighing, and locking. Its main function is to receive and support full ladles of molten steel hoisted from the steelmaking workshop. By rotating, it transfers the ladle from the receiving position to the tundish above the pouring position on the continuous casting machine. It can also return empty ladles to the steel receiving position for crane transport, thus enabling continuous casting of multiple heats. Each time the ladle's sliding gate is opened, the high-temperature molten steel inside rapidly oxidizes the covering agent in the tundish, generating a large amount of smoke and dust, which cannot meet the requirements of the production environment. Therefore, a movable dust collection hood needs to be installed in the ladle turret area to collect the smoke and dust. By connecting to the dust collection pipeline, the workshop's dust collection device will draw the generated smoke and dust into the dust collection system, preventing the flue gas from overflowing and achieving the goal of clean production. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for determining the exhaust volume of a dust collector hood for a mobile ladle rotary table, which addresses the above-mentioned deficiencies in the existing technology. This method can quantitatively determine the exhaust volume standard of the dust collector hood, maximize emission control, minimize airflow requirements, minimize pressure loss energy, minimize the impact on process efficiency and employee productivity, ensure no obvious smoke or dust spillage during the entire production process, and significantly improve the working environment of the casting platform.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: A method for determining the exhaust volume of a dust collector hood on a mobile ladle rotary table includes the following steps: calculating the air intake velocity on the projected area of ​​the dust collector hood when it is in the working position. The volumetric flow rate of air displaced by molten steel during the initial pouring process in the tundish. Then, according to formula (3), the exhaust volume Q of the dust collector hood is obtained as follows:

[0006] in, —Width of the dust collector hood opening; —Dust collector hood opening cross-sectional length; The dust collection hood is positioned above the ladle rotary table.

[0007] According to the above technical solution, the volumetric flow rate Vg of air displaced by the molten steel in the intermediate ladle during the initial pouring period is:

[0008] in, —The volumetric flow rate of molten steel filled into the intermediate ladle during the initial pouring phase, in m³ 3 / h; —Temperature of molten steel at the start of pouring; —Ambient temperature in the continuous casting workshop.

[0009] According to the above technical solution, the volumetric flow rate Vs of molten steel filled into the intermediate ladle during the initial casting period is: V s =

[0010] in, —Diameter of the sliding gate nozzle of the ladle; g—acceleration due to gravity; —The height of the liquid level in the ladle when pouring begins.

[0011] According to the above technical solution, the dust removal hood is a heat-receiving exhaust hood.

[0012] According to the above technical solution, the cross-sectional dimensions of the dust collector hood shall not be less than the dimensions of the polluted airflow at the hood opening.

[0013] According to the above technical solution, the dust removal hood is set on the track, and the dust removal hood is connected to a transmission device, which drives the dust removal hood to move back and forth along the track.

[0014] According to the above technical solution, the track includes a low track and a high track, which are arranged on the outside and inside of the dust removal hood, respectively.

[0015] According to the above technical solution, the dust hood is sealed by a top plate and side plates arranged on the four sides of the top plate.

[0016] According to the above technical solution, the side plate is made up of multiple chain plates spliced ​​together.

[0017] According to the above technical solution, the dust removal hood is equipped with an air intake and an air exhaust port on the side of the dust removal hood. The air intake and air exhaust ports are connected by an internal pipeline of the dust removal hood.

[0018] According to the above technical solution, the dust removal hood covers the entire ladle, intermediate tank and casting area during the dust removal process.

[0019] The present invention has the following beneficial effects: It can quantitatively determine the exhaust volume standard of the dust hood, control emissions to the maximum extent, minimize airflow requirements, minimize pressure loss energy, minimize the impact on process efficiency and employee productivity, ensure no obvious smoke or dust spillage during the entire production process, and significantly improve the working environment of the pouring platform. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the dust removal hood of the mobile ladle rotary table in an embodiment of the present invention; Figure 2 yes Figure 1 Top view; In the figure, 1-dust hood, 2-ladle, 3-ladle rotary table, 4-ladle sliding nozzle, 5-ladle protective sleeve, 6-intermediate tank, 7-intermediate tank car, 8-crystallizer, 9-vibration device, 10-support and guide device, 11-straightening machine, 12-flame cutter, 13-spindle rod, 14-roller conveyor; 1.1-Low rail, 1.2-High rail, 1.3-Transmission device, 1.4-Air intake, 1.5-Inner air duct, 1.6-Exhaust vent, 1.7-Chain plate. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] Reference Figures 1-2 As shown, in one embodiment of the present invention, a method for determining the exhaust volume of a mobile ladle rotary table dust collector hood is provided. The dust collector hood 1 is arranged above the ladle rotary table area, and the exhaust volume Q of the dust collector hood 1 is:

[0023] in, —The air intake velocity over the projected area of ​​the dust collector hood, in m / s; —Width of the dust collector hood opening, in meters; —Dust collector hood opening cross-sectional length, m; —The volumetric flow rate (m³) of air displaced by molten steel during the initial pouring phase in the intermediate ladle. 3 / h.

[0024] Furthermore, the volumetric flow rate Vg of air displaced by the molten steel in the tundish during the initial pouring is:

[0025] in, —The volumetric flow rate of molten steel filled into the intermediate ladle during the initial pouring phase, in m³ 3 / h; —Temperature of molten steel at the start of pouring, °C; —Ambient temperature in the continuous casting workshop, °C.

[0026] Furthermore, the volumetric flow rate Vs of molten steel filled into the tundish during the initial pouring is: V s =

[0027] in, — Diameter of the sliding gate nozzle of the ladle, mm; g—acceleration due to gravity, m / s²; —The height of the liquid level in the ladle at the start of pouring, in mm.

[0028] Furthermore, the dust removal hood 1 is a heat-receiving exhaust hood.

[0029] Furthermore, the cross-sectional dimensions of the dust hood 1 are not less than the dimensions of the polluted airflow at the hood opening.

[0030] Furthermore, the dust hood 1 is mounted on a track and is connected to a transmission device, which drives the dust hood 1 to move back and forth along the track.

[0031] Furthermore, the track includes a low track and a high track, which are respectively arranged on the outside and inside of the dust removal hood 1.

[0032] Furthermore, the dust hood 1 is sealed by a top plate and side plates arranged around the four sides of the top plate; the bottom is open for dust extraction.

[0033] Furthermore, the top plate is made of steel plate; the side plates are spliced ​​together from multiple chain plates 1.7.

[0034] Furthermore, the dust hood 1 is equipped with an air intake 1.4, which is arranged to face the impact zone of the intermediate tank. The side of the dust hood 1 is equipped with an exhaust port 1.6. The air intake 1.4 and the exhaust port 1.6 are connected by an internal pipe 1.5 of the dust hood 1.

[0035] Working principle of the invention: See Figure 1Each time casting begins, the intermediate ladle car 7 moves left and right along the rails to the casting area. Then, the ladle sliding nozzle 4 is opened, and the molten steel in the ladle 2 flows into the intermediate ladle 6 through the ladle protective sleeve 5 below it for buffering and purification. It is then evenly distributed to each outlet of the intermediate ladle 6. Once the set casting height in the intermediate ladle 6 is reached, the stopper is opened and the molten steel is injected into each crystallizer 8 through the submerged entry nozzle. After the start-up time is reached, the straightening machine 11 draws the billet at the set starting speed and simultaneously starts the vibration device 9, the secondary cooling spray water, and the secondary cooling exhaust steam fan. After primary cooling, the billet with a liquid core gradually moves downward along the arc-shaped support guide device 10. At this time, cooling water is sprayed directly onto the billet for secondary cooling. After being straightened by the straightening machine 11, the billet is pulled out by the ingot derrick 13. The billet is separated from the ingot derrick by the ingot removal device. The fire cutter 12 cuts the billet into the required length and transports it to the subsequent rolling process through the roller conveyor 14, thus completing the continuous casting production.

[0036] See Figure 2 Each time the sliding gate 4 of the ladle is opened, the high-temperature molten steel inside rapidly oxidizes the covering agent in the tundish, generating a large amount of dust. To improve the production environment, a movable dust hood 1 needs to be installed in the ladle turret area to collect the dust. This includes a low rail 1.1 located above the ladle operating platform, a high rail 1.2 outside the crane beam, and a sealed movable hood formed by steel plates on the top and chain plates 1.7 on the sides of the ladle turret 3. It can move left and right along the rails via a transmission device 1.3, facilitating the hoisting of the tundish 6 in the pouring area. The suction port 1.4 inside the dust hood 1 is positioned as directly as possible towards the impact zone of the tundish to improve dust collection efficiency, and is connected to external dust collection facilities via an internal pipeline 1.5 and an exhaust port 1.6 on the side of the movable hood.

[0037] The time t taken for opening the ladle sliding gate 4 to start the pouring operation after the ladle 2 reaches the pouring position is calculated according to formula (1). This portion of high-temperature molten steel rapidly oxidizes the covering agent in the tundish, forming dust, and simultaneously replaces the original air in tundish 6 with heat due to the temperature difference. The two combine to form smoke and dust. This working condition is characterized by a large amount of induced hot airflow generated by the process. The dust collector should be a heat-receiving exhaust hood, and its cross-sectional dimensions should not be smaller than the dimensions of the polluted airflow at the hood opening. Finally, the required exhaust volume of dust collector 1 is calculated according to formula (3). : V s = (1) in: —The volumetric flow rate of molten steel filled into the intermediate ladle during the initial pouring phase, in m³ 3 / h; — Diameter of the sliding gate nozzle of the ladle, mm; —Liquid level in the ladle at the start of pouring, in mm; (2) in: —The volumetric flow rate (m³) of air displaced by molten steel during the initial pouring phase in the intermediate ladle. 3 / h; —Temperature of molten steel at the start of pouring, °C; —Ambient temperature in the continuous casting workshop, °C; (3) in: —Required exhaust volume for dust collector hood, m 3 / h; —The air intake velocity over the enlarged area of ​​the dust collector hood, m / s; —Width of the dust collector hood opening, in meters; —Dust collector hood opening cross-sectional length, m; In summary, to improve the working environment of the ladle turret area in the continuous casting workshop, this invention provides a movable ladle turret dust hood that covers the entire ladle, tundish, and casting area. Without affecting production, the height of the dust hood is as close as possible to the top of the ladle, and the lower edge of the dust hood covers the entire ladle and tundish area as much as possible. The required exhaust volume of the dust hood in the ladle turret area is calculated quantitatively using a formula, which can ensure the dust collection effect and reduce the load and energy consumption of external dust removal facilities.

[0038] In summary, steelmaking is a key area for ultra-low emission transformation and one of the most difficult areas to control fugitive dust. Among them, the installation of dust removal equipment in the ladle turntable area of ​​the continuous casting workshop is the most easily overlooked and most limited by the actual site conditions. Many steel companies are not very clear about how to transform this point and what effects should be achieved after the transformation. The design challenges of dust hoods for ladle turrets lie in several aspects: the weighing arm of the ladle turret needs to rotate, and adding a dust hood would disrupt production; there is insufficient space in the ladle turret area to accommodate large dust collection facilities; the ladle turret generates dust explosively, and a small dust hood area would be insufficient to completely collect the large amounts of smoke and dust generated during casting; an excessively large dust hood would require a high airflow rate from the dust collector, resulting in higher energy consumption and greater space requirements; poor sealing of the tundish can also generate smoke and dust during continuous casting, and the dust hood design must also consider and prevent such problems. Therefore, the placement of dust hoods in the ladle turret area of ​​the continuous casting workshop requires careful consideration of numerous constraints, including site size limitations, the type of steel being produced, dust collector capacity design, and dust collection ductwork. The dust hood design aims to balance multiple characteristics to achieve optimal system performance, including: maximizing emission control, minimizing airflow requirements, minimizing pressure loss (energy), and minimizing the impact on process efficiency and employee productivity. Regardless of the design, ensuring no significant smoke and dust spillage throughout the entire production process is a fundamental requirement.

[0039] The present invention provides a mobile ladle turret dust hood that covers the entire ladle, intermediate tank and casting area. By quantitatively calculating the required exhaust volume of the dust hood in the ladle turret area, it ensures that no visible smoke or dust overflows during the production process, and greatly improves the working environment of the casting platform.

[0040] The above are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent changes made in accordance with the claims of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for determining the exhaust volume of a dust collector hood on a mobile ladle rotary table, characterized in that, Includes the following steps: Calculate the air intake velocity over the projected area of ​​the dust collector hood. The volumetric flow rate of air displaced by molten steel during the initial pouring process in the tundish. Then, according to formula (3), the exhaust volume Q of the dust collector hood is obtained as follows: （3） in, The width of the dust collector hood opening is in meters (m). The length of the dust collector hood opening is in meters (m). The suction velocity of air over the projected area of ​​the dust collector hood is expressed in m / s; the dust collector hood is positioned above the ladle rotary table. The volumetric flow rate Vg of air displaced by molten steel during the initial pouring is as follows: （2） in, The volumetric flow rate of molten steel filled into the tundish during the initial pouring phase, in m³. 3 / h; The temperature of the molten steel at the time of pouring is ℃; The ambient temperature in the continuous casting workshop is ℃; The volumetric flow rate Vs of molten steel filled into the tundish during the initial pouring is: V s = （1） in, — Diameter of the sliding gate of the ladle, mm; g— Acceleration due to gravity, m / s²; —Liquid level in the ladle at the start of pouring, in mm; The dust collector hood is mounted on a track and is connected to a transmission device, which drives the dust collector hood to move back and forth along the track. The track includes a low track and a high track, which are arranged on the outside and inside of the dust collection hood, respectively; The dust collector hood is equipped with an air intake and an air exhaust port on its side. The air intake and exhaust ports are connected by an internal pipe within the dust collector hood. During the dust removal process, the dust hood covers the entire ladle, intermediate tank, and pouring area; Each time casting begins, the intermediate ladle car moves left and right along the rails to the casting area. Then, the ladle sliding gate is opened, and the molten steel in the ladle flows into the intermediate ladle through the ladle protective sleeve below for buffering and purification. It is then evenly distributed to each outlet of the intermediate ladle. Once the set casting height in the intermediate ladle is reached, the stopper is opened and the molten steel is injected into each crystallizer through the submerged entry nozzle. After the starting time is reached, the straightening machine draws the billet at the set starting speed and simultaneously starts the vibration device, the secondary cooling spray water, and the secondary cooling exhaust steam fan. After primary cooling, the billet with a liquid core gradually moves downward along the arc-shaped support guide device. At this time, cooling water is sprayed directly onto the billet for secondary cooling. After being straightened by the straightening machine, the billet is pulled out by the ingot derrick and separated from the ingot derrick by the ingot removal device. The fire cutter cuts the billet into the required length and transports it to the subsequent rolling process via roller conveyor, thus completing the continuous casting production. Each time the ladle sliding gate is opened, the high-temperature molten steel inside rapidly oxidizes the covering agent in the intermediate tank, generating a large amount of smoke and dust. In order to improve the production environment, a movable dust collector is installed in the ladle rotary table area to collect the smoke and dust. It can move left and right along the track through the transmission device, which facilitates the hoisting of the intermediate tank in the pouring area. The time t taken to open the ladle sliding gate for pouring after the ladle reaches the pouring position is calculated according to formula (1) as follows: This portion of high-temperature molten steel rapidly oxidizes the covering agent in the tundish, forming dust, and simultaneously replaces the original air in the tundish with heat due to the temperature difference. The two combine to form smoke and dust. The working condition is that the process generates a large amount of induced hot airflow. The dust collector is a heat receiving exhaust hood, and its cross-sectional size is not less than the size of the polluted airflow at the hood opening. Finally, the required exhaust volume of the dust collector is calculated according to formula (3). .

2. The method for determining the exhaust volume of the dust collector hood of the mobile ladle rotary table according to claim 1, characterized in that, The dust hood is sealed by a top plate and side plates arranged around the four sides of the top plate.

Images