Method for improving steel ladle turnover efficiency

Abstract

The invention discloses a method for improving steel ladle turnover efficiency in the field of steel ladle turnover. The method comprises the following steps that a steel ladle is hoisted to a rotary table of a continuous casting machine closest to a converter through a crown block to be installed; the continuous casting machines are sequentially started at intervals, after molten steel in steel ladles on the continuous casting machines is used up, the continuous casting machines stop working, and the steel ladles are offline; steel ladle deslagging is carried out, and hot repair treatment is carried out after steel ladle deslagging; in the hot repair treatment, a detection device collects image information of flames in the steel ladle, and whether the air bricks in the steel ladle are burnt through or not is judged according to the image information. According to the method for improving the turnover efficiency of the steel ladle, the turnover rate of the steel ladle is improved by optimizing all the production steps, the continuous casting machine is started at the interval time, so that the slag pouring time of the steel ladle is staggered, the blank pulling speed of the continuous casting machine is adjusted, and molten steel in the steel ladle is used up in different time periods; whether the air brick is burnt through or not is judged through image information in the steel ladle, and the hot repair work efficiency is improved.

Description

Technical Field

[0001] The invention relates to the field of continuous casting, and in particular to a method for improving ladle turnover efficiency. Background Art

[0002] During the steelmaking process, ladles play a crucial role in loading and transporting molten steel. This role is closely linked to the stable control of molten steel temperature, the production rhythm within the steelmaking plant, and logistics regulation. As a key indicator of ladle management and control, effectively improving ladle turnover is crucial for reducing ladle turnover, optimizing ladle thermal conditions, lowering converter tapping temperatures, and maintaining constant casting speeds on continuous casters. Therefore, maximizing ladle turnover while ensuring continuous and orderly production has long been a goal for steelmaking plants. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for improving the turnover efficiency of a ladle, optimize each step during production, and improve the turnover rate of the ladle.

[0004] In order to solve the above technical problems, the following technical solutions are adopted:

[0005] The present invention provides a method for improving ladle turnover efficiency, comprising the following steps:

[0006] The high-temperature molten steel in the converter is loaded into a ladle, which is then hoisted by an overhead crane to the turntable of the continuous casting machine closest to the converter, achieving the shortest distance between the converter and the continuous casting machine.

[0007] The continuous casting machines are started at intervals in sequence, and the started continuous casting machines start working. When the molten steel in the ladle on the continuous casting machine is used up, the continuous casting machine stops working and the ladle is taken off the line;

[0008] When each continuous casting machine is operating, the operating speed of the continuous casting machine is adjusted according to the vacancy status of the ladle hot repair station in the factory building; when the hot repair station is not vacant, the operating speed of the continuous casting machine is reduced to delay the ladle from the continuous casting machine to be taken off the line; when the hot repair station is vacant, the operating speed of the continuous casting machine is increased to allow the ladle to be taken off the line earlier;

[0009] After the ladle is off the line, the ladle is slaged and then heat-repaired;

[0010] During the thermal repair process, the detection device collects image information of the flame in the ladle and determines whether the air bricks in the ladle are burned through based on the image information. When the image of the flame in the ladle is black, it indicates that the air bricks are burned through. When the air bricks are burned through, the thermal repair process of the ladle is completed.

[0011] After hot repair, the ladle is hoisted to the converter and loaded with high-temperature molten steel for use again.

[0012] Optionally, after the ladle has been used 40 times, the ladle is subjected to cold repair treatment.

[0013] Optionally, during the thermal repair treatment, the coal-burning oxygen device is extended into the ladle to flame heat the air bricks in the ladle, and at the same time, cooling gas is blown to the side of the air bricks facing away from the coal-burning oxygen device through the air blowing cooling device. The detection device collects image information of the flame in the ladle, and the control system controls the closure of the coal-burning oxygen device and the air blowing cooling device according to the image information.

[0014] Optionally, the interval time for starting each continuous casting machine ranges from 8 to 11 minutes.

[0015] Optionally, when installing the ladle, clean the debris in the inner cavity of the base brick on the ladle, evenly apply fire mud around the upper water inlet column, and then place one end of the upper water inlet into the inner cavity of the base brick. The end face of the upper water inlet and the bottom end face of the inner cavity of the base brick are spaced 1-2 mm apart. After the fire mud is dry, install the slide plate, which is used to control the speed at which the molten steel in the ladle flows out of the upper water inlet.

[0016] Optionally, before the ladle is newly put on line, that is, before the ladle is charged with high-temperature molten steel for the first time, the ladle is baked for 2 hours before installing the water inlet and the air bricks.

[0017] Optionally, the working speed of the continuous casting machine is adjusted according to the vacancy status of the ladle hot repair station, and the initial billet drawing speed of the continuous casting machine is set to 1.15m / min. When there is a vacant ladle hot repair station, the billet drawing speed of the continuous casting machine is set to 1.2m / min; when all the ladle hot repair stations have ladles under hot repair, the billet drawing speed of the continuous casting machine is set to 1.1m / min.

[0018] Optionally, the temperature of the high-temperature molten steel in the converter is controlled between 1580°C and 1620°C to ensure a suitable tapping temperature.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The method for improving ladle turnover efficiency provided by the present invention improves the turnover rate of the ladle by optimizing each production step. The continuous casting machine is started at intervals so that the molten steel in the ladle of each continuous casting machine is used up at different time periods, thereby staggering the slag pouring time of the ladle. The casting speed of the continuous casting machine is adjusted so that the molten steel in the ladle is used up at different time periods. During the hot repair of the ladle, the image information in the ladle is used to determine whether the permeable bricks are burned through, thereby improving the efficiency of the hot repair work.

[0021] 2. The method provided by the present invention controls the temperature of the molten steel in the converter, thereby controlling the temperature of the molten steel when it is loaded into the ladle. This can reduce the impact of fluctuations in the casting speed of the continuous casting machine caused by fluctuations in the molten steel temperature on the continuous casting time, thereby improving the ladle turnover efficiency. The temperature of the molten steel entering the ladle is lower, which can also increase the service life of the ladle. DETAILED DESCRIPTION

[0022] In the description of the present invention, unless otherwise specified, "plurality" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, an indirect connection through an intermediate medium, or it can be internal communication between two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood based on specific circumstances.

[0023] Example 1

[0024] This embodiment provides a method for improving ladle turnover efficiency, comprising the following steps:

[0025] The high-temperature molten steel in the converter is loaded into a ladle, which is then hoisted by an overhead crane to the turntable of the continuous casting machine closest to the converter, achieving the shortest distance between the converter and the continuous casting machine.

[0026] The continuous casting machines are started at intervals in sequence, and the started continuous casting machines start working. When the molten steel in the ladle on the continuous casting machine is used up, the continuous casting machine stops working and the ladle is taken off the line;

[0027] When each continuous casting machine is operating, the operating speed of the continuous casting machine is adjusted according to the vacancy status of the ladle hot repair station in the factory building; when the hot repair station is not vacant, the operating speed of the continuous casting machine is reduced to delay the ladle from the continuous casting machine to be taken off the line; when the hot repair station is vacant, the operating speed of the continuous casting machine is increased to allow the ladle to be taken off the line earlier;

[0028] After the ladle is off the line, the ladle is slaged and then heat-repaired;

[0029] During the thermal repair process, the detection device collects image information of the flame in the ladle and determines whether the air bricks in the ladle are burned through based on the image information. When the image of the flame in the ladle is black, it indicates that the air bricks are burned through. When the air bricks are burned through, the thermal repair process of the ladle is completed.

[0030] After hot repair, the ladle is hoisted to the converter and loaded with high-temperature molten steel for use again.

[0031] After the ladle is put online and then taken offline for hot repair treatment, it is used once. After being used 40 times, the ladle enters cold repair treatment, and the ladle after cold repair treatment is put online again.

[0032] There are usually 2-4 continuous casting machines and one overhead crane in a factory. The overhead crane is used to lift the ladle to the turntable of the continuous casting machine and install it for continuous casting production. When a ladle is lifted to the No. 1 continuous casting machine to start production, wait for 8 to 11 minutes before starting the No. 2 continuous casting machine. Other continuous casting machines are started at intervals. When the molten steel on the No. 1 continuous casting machine is used up, the ladle is slaged and a new ladle is lifted to the No. 1 continuous casting machine to start production. When the molten steel in the No. 2 ladle is used up, the ladle on the No. 2 continuous casting machine is replaced. The operations are performed in sequence to avoid waiting between the overhead cranes to extend the ladle slag deslagging time, stagger the ladle slag deslagging time, and improve production efficiency.

[0033] The replaced ladle needs to be heat treated before it can be loaded with molten steel. The heat treatment stations are limited. The billet pulling speed of the continuous casting machine, that is, the production speed, is adjusted according to the vacancy status of the hot repair station. When there is a vacancy in the hot repair station, the billet pulling speed is increased and the ladle can be taken off the line in advance for hot repair treatment. When there is no vacancy in the hot repair station, the billet pulling speed is reduced and the ladle is delayed from being taken off the line, thereby increasing the utilization rate of the hot repair station and improving the turnover efficiency of the ladle.

[0034] During the heat repair process, the image information is used to determine whether the air bricks of the ladle are burned through. After burning through, the heat repair device is closed. There is no need to manually shut down the device and stop working for observation, which improves the efficiency of the heat repair process.

[0035] Example 2

[0036] This embodiment provides a method for improving the turnover efficiency of a ladle based on the first embodiment. The hot repair treatment of the ladle specifically includes: a crane lifts the ladle to the hot repair station so that the inlet of the ladle faces the coal-burning oxygen device, and then extends the coal-burning oxygen device from the inlet of the ladle into the ladle to flame heat the air bricks in the ladle, so that the steel slag attached to the air bricks melts into liquid, thereby separating from the air bricks, and at the same time, cooling gas is blown to the side of the bottom-blown bricks facing away from the coal-burning oxygen device through the air blowing cooling device. Since the air bricks themselves have small air vents, the cooling gas will pass through the air vents, which will accelerate the shedding of the steel slag on the one hand and cool the air bricks on the other hand. Since the breathable bricks after flame heating are in a high-temperature state and appear red in appearance, the bottom-blown bricks will cool down after being cooled by cooling gas, and will thus change from red to black. Therefore, the image information collected by the visual detection device can be compared through the control device. When the color of the bottom-blown bricks obtained is black, it is judged that the breathable bricks are burned through, and the control system then stops the coal-oxygen burning device and the air-blowing cooling device to complete the heat repair treatment. The device is manually stopped during lunch break and then observed again. If it has not burned through, the device needs to be started again. The optimized heat repair treatment process can improve the efficiency of the heat repair treatment, thereby improving the turnover efficiency of the ladle.

[0037] Stagger the casting times of each continuous casting machine, starting one every 8 to 11 minutes. This staggers the ladle slag emptying time and prevents the overhead cranes from waiting for each other, which would otherwise extend the ladle slag emptying time. The initial casting speed of each continuous casting machine is set at 1.15m / min. The time period for each ladle to be cast after arriving at the continuous casting machine is basically the same. Generally, steel companies have 2-4 continuous casting machines operating simultaneously in the same plant, but the overhead cranes that lift the ladles can only lift one ladle at a time. Compared to traditional continuous casting machines that start casting at the same time, staggering the start times of each continuous casting machine is more conducive to improving the efficiency of the overhead crane lifting the ladle.

[0038] By adjusting the casting speed of the continuous casting machine, the casting time of each ladle of molten steel in the continuous casting process is controlled. When there are no ladles at the ladle hot repair station, the casting speed of the continuous casting machine is increased, and the casting speed of the continuous casting machine is set to 1.2m / min. Production speed is accelerated to allow ladles to be taken off the production line earlier. When all ladles are being repaired at the ladle hot repair station, the continuous casting machine is slowed down, and the casting speed of the continuous casting machine is set to 1.1m / min. Production speed is reduced, which delays the ladle's removal from the production line and improves the utilization rate of the ladle hot repair station.

[0039] When installing the ladle water inlet, specifically include: cleaning the debris in the cavity of the base brick, after the water inlet is properly installed, use fire mud to evenly apply the surrounding area of ​​the water inlet column with a moderate thickness, use tools to flatten the water inlet, and place it into the cavity of the base brick, requiring uniform clearance around it, and install it in place. The end face should be 1-2mm lower than the bottom plane of the base slide cavity. For newly-launched ladles, bake for 2 hours before installing the water inlet and air bricks; for ladles with normal turnover, baking is not required. After the fire mud on the water inlet is dry and the water inlet is fixed, the slide can be installed. While ensuring that the mud gap is full, the fire mud between the slide and the water inlet should be as little as possible to avoid the water inlet from moving inward under pressure. This step can effectively prevent the ladle from not flowing by itself, thereby shortening the ladle turnover.

[0040] The temperature of the molten steel in the converter is controlled between 1580°C and 1620°C. The tapping temperature depends on the melting point of the steel, the required superheat for pouring, and the temperature drop during tapping and pouring: Ttap = tmelt + Δtsuperheat + Δt. After the production plan is issued, the converter steel begins blowing. During this process, the temperature is adjusted based on the furnace conditions. In the early stages of blowing, if the carbon flame appears early, it indicates that the bath temperature is too high. This can be controlled by adding the second batch of material in advance. Conversely, if the carbon flame appears late, it indicates that the temperature is low in the early stages, and the lance should be lowered to increase the bath temperature. In the middle stages of blowing, the bath temperature is assessed by the color of the flame at the furnace mouth. If the flame is yellowish, the temperature is too high and ore should be added to cool it down. If the flame is bluish, the temperature is too low and ore should be added to cool it down. This can reduce the impact of fluctuations in the casting speed of the continuous casting machine caused by fluctuations in the molten steel temperature on the continuous casting casting time, thereby improving the turnover efficiency of the ladle, reducing the steel tapping temperature, and increasing the service life of the ladle.

[0041] After the ladle has been used 40 times, it will enter cold repair. The cold repair time of the ladle is relatively long. After the ladle is put back online after cold repair, it needs to be baked for 2 hours before the water inlet and air bricks are installed to ensure that the temperature of the newly put online ladle itself is close to the temperature of the molten steel.

[0042] The method for improving the ladle turnover efficiency provided in this embodiment improves the ladle turnover efficiency by spacing the continuous casting machine opening time, optimizing the ladle heat repair treatment process, controlling the continuous casting machine billet drawing speed and controlling the converter molten steel temperature, thereby achieving low-cost and high-efficiency production of molten steel smelting and casting.

[0043] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving ladle turnover efficiency, characterized in that: The following steps are involved: The high-temperature molten steel in the converter is loaded into a ladle, which is then hoisted by an overhead crane to the turntable of the continuous casting machine closest to the converter for installation; The continuous casting machines are started at intervals in sequence, and the started continuous casting machines start working. When the molten steel in the ladle on the continuous casting machine is used up, the continuous casting machine stops working and the ladle is taken off the line; When each continuous casting machine is operating, the operating speed of the continuous casting machine is adjusted according to the vacancy status of the ladle hot repair station in the factory building; when the hot repair station is not vacant, the operating speed of the continuous casting machine is reduced to delay the ladle from the continuous casting machine to be taken off the line; when the hot repair station is vacant, the operating speed of the continuous casting machine is increased to allow the ladle to be taken off the line earlier; After the ladle is off the line, the ladle is slaged and then heat-repaired; During the thermal repair process, the detection device collects image information of the flame in the ladle and determines whether the air bricks in the ladle are burned through based on the image information. When the image of the flame in the ladle is black, it indicates that the air bricks are burned through. When the air bricks are burned through, the thermal repair process of the ladle is completed. After hot repair, the ladle is hoisted to the converter and loaded with high-temperature molten steel for use again.

2. The method for improving ladle turnover efficiency according to claim 1, characterized in that: After the ladle has been used 40 times, it is subjected to cold repair treatment.

3. The method for improving ladle turnover efficiency according to claim 1, characterized in that: During the thermal repair treatment, the coal-burning oxygen device is extended into the ladle to flame heat the air bricks in the ladle, and at the same time, cooling gas is blown to the side of the air bricks facing away from the coal-burning oxygen device through the air blowing cooling device. The detection device collects image information of the flame in the ladle, and the control system controls the closure of the coal-burning oxygen device and the air blowing cooling device based on the image information.

4. The method for improving ladle turnover efficiency according to claim 1, characterized in that: The interval time for starting each continuous casting machine ranges from 8 to 11 minutes.

5. The method for improving ladle turnover efficiency according to claim 1, characterized in that: When installing the ladle, clean the debris in the inner cavity of the base brick on the ladle, evenly apply fire mud around the upper water inlet column, and then put one end of the upper water inlet into the inner cavity of the base brick. The end face of the upper water inlet and the bottom end face of the inner cavity of the base brick are spaced 1-2mm apart. After the fire mud is dry, install the slide plate, which is used to control the speed at which the molten steel in the ladle flows out of the upper water inlet.

6. The method for improving ladle turnover efficiency according to claim 1, characterized in that: Before the ladle is put into operation, that is, before the ladle is charged with high-temperature molten steel for the first time, the ladle should be baked for 2 hours before installing the water inlet and air bricks.

7. The method for improving ladle turnover efficiency according to claim 1, characterized in that: The working speed of the continuous casting machine is adjusted according to the vacancy status of the ladle hot repair station. The initial billet drawing speed of the continuous casting machine is set to 1.15m / min. When there is a vacant ladle hot repair station, the billet drawing speed of the continuous casting machine is set to 1.2m / min; when all the ladle hot repair stations have ladles under hot repair, the billet drawing speed of the continuous casting machine is set to 1.1m / min.

8. The method for improving ladle turnover efficiency according to claim 1, characterized in that: The temperature of the high-temperature molten steel in the converter is controlled between 1580°C and 1620°C to ensure a suitable tapping temperature.