Method for predicting time of slag entrapment phenomenon in steel ladle pouring and steel ladle pouring method

Abstract

The invention discloses a method for predicting slag entrapment time in steel ladle pouring and a steel ladle pouring method, and belongs to the field of ferrous metallurgy process detection. The prediction method comprises the following steps: establishing an M-H model between the theoretical molten steel residual mass M and the theoretical real-time liquid level height H of the molten steel in a steel ladle; establishing an H-t model between the theoretical real-time liquid level height H of the molten steel in the steel ladle and the theoretical outflow time t of the molten steel; obtaining a theoretical M-t model; when the proportion of the difference value between the theoretical residual mass M of the molten steel and the actually measured residual mass of the molten steel in the M-t model reaches 10%, the theoretical outflow time of the molten steel is the predicted time for generating the slag entrapment phenomenon. The pouring method comprises the steps that pouring operation is started, the pouring operation is stopped when the predicted slag entrapment phenomenon occurs, and the pouring operation is carried out again after standing is carried out until the slag entrapment phenomenon is finished; and obtaining the time when the slag entrapment phenomenon is generated in the next prediction, stopping pouring, and repeating the steps until the molten steel in the steel ladle is poured completely.

Description

Technical Field

[0001] The present invention belongs to the field of steel metallurgy process detection, and more specifically, relates to a method for predicting the time of slag entrainment during ladle pouring and a ladle pouring method. Background Art

[0002] Properties such as the strength, lifespan, corrosion resistance, and thermal stability of steel all require extremely high levels in the current environment. Improving the cleanliness of steel is one of the important directions for improving the properties of steel products. Reducing the mixing of impurities into the molten steel during the smelting process is a major bottleneck for high-end metallurgical products and an important criterion for measuring the advancement of the steel industry. During the transfer of molten steel from the converter to the ladle for secondary refining and from the ladle to the tundish for continuous casting, the phenomenon of confluence vortices will occur. Due to the appearance of confluence vortices, slag entrainment and gas suction phenomena will occur, further increasing the content of impurities and gases in the molten steel and reducing the purity of the molten steel. This phenomenon will manifest as the interaction between various impurities and the molten steel during the steel smelting process, seriously affecting the quality of the steel and resulting in the steel quality being lower than expected.

[0003] When producing high-purity steel grades, the weighing sensors on the ladle turntable can record the real-time weight of the molten steel in the ladle. By observing the change in the weight of the molten steel, the real-time height of the molten steel surface can be obtained. During the existing ladle pouring process, by recording the weight value when the molten steel generates vortices and stopping the pouring whenever the weighing sensor reaches this value during the subsequent pouring process, the slag entrainment behavior during the ladle pouring process can be controlled to a certain extent, thereby achieving the purpose of improving the purity of the molten steel. However, this method requires the operator to have rich experience, and the process is cumbersome. Moreover, the working conditions during the pouring process of each heat of steel are different, and the height of the vortices generated is different. Therefore, this method of observing and controlling vortices can only preliminarily control the slag entrainment behavior of the ladle, and how to judge the time of slag entrainment in the ladle by a simpler method has become a problem worthy of discussion. Summary of the Invention

[0004] 1. Problems to be Solved

[0005] Aiming at the problem that the existing judgment of the time of slag entrainment phenomenon depends on manual observation, the present invention provides a method for predicting the time of slag entrainment during ladle pouring, which obtains the time for predicting the occurrence of slag entrainment phenomenon by collecting the ladle mass change curve. Subsequently, a ladle pouring method is provided to stop pouring after reaching the time for predicting the occurrence of slag entrainment phenomenon, thereby achieving the purpose of improving the purity of the molten steel.

[0006] 2. Technical Solutions

[0007] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0008] According to the object of the present invention, the present invention provides a method for predicting the time of slag entrainment phenomenon during ladle pouring, and the steps are as follows:

[0009] S1. Establish an M-H model between the theoretical remaining mass M of molten steel in the ladle and the theoretical real-time liquid level height H of the molten steel: f(H)=M;

[0010] S2. Establish an H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle and the theoretical outflow time t of the molten steel:

[0011]

[0012] In the formula: H1 is the initial liquid level height of the molten steel in the ladle, ψ is the flow velocity coefficient of the water outlet (the flow velocity coefficient of the cylindrical outer nozzle is 0.82), g is the acceleration due to gravity, A0 is the cross-sectional area of the ladle bottom, and A1 is the cross-sectional area of the water outlet;

[0013] S3. According to the M-H model in step S1 and the H-t model in step S2, obtain the theoretical M-t model;

[0014] S4. When the ratio of the difference between the theoretical remaining mass M of the molten steel and the measured remaining mass of the molten steel in the M-t model to the theoretical remaining mass M of the molten steel reaches 10%, the theoretical outflow time of the molten steel at this time is the predicted time of slag entrainment phenomenon.

[0015] In the case of adopting the above technical solution, no slag entrainment phenomenon will occur in the theoretical M-t model, but slag entrainment will occur in the actual production process. If the diameter of the water outlet is d, the instantaneous flow rate q when no vortex is generated in the molten steel is:

[0016]

[0017] When a vortex is generated during the pouring process, its instantaneous flow rate will decrease, and the specific instantaneous flow rate of the molten steel is:

[0018]

[0019] Among them, d 渣 is the diameter of the generated vortex, and the liquid at the center of the vortex is replaced by steel slag. Since the density of steel slag is much smaller than that of molten steel, the slope of the mass change curve of the weighing sensor will decrease with the appearance of the vortex, generating an obvious inflection point. By observing the time when the inflection point appears, this time is the time when slag entrainment starts during ladle pouring.

[0020] As a possible implementation solution, in the step S1, the establishment process of the M-H model is as follows:

[0021] Measure the diameter of the ladle bottom as D0, the diameter of the ladle top as D, the initial liquid level height of the molten steel in the ladle as H1, the height of the ladle as H0, and the diameter of the molten steel liquid level in the ladle as D1, and obtain

[0022]

[0023] Therefore, the initial total volume V of the molten steel is:

[0024]

[0025] And the initial total mass M0 of the molten steel is:

[0026] M0 = ρV;

[0027] In the formula, ρ is the density of the molten steel;

[0028] To sum up, there is

[0029]

[0030] That is, let: M0 = M, H1 = H;

[0031]

[0032] Then the M-H model is:

[0033]

[0034] As a possible implementation solution, in the step S2, the establishment process of the H-t model is:

[0035] Measure the angle θ at which the ladle side wall is inclined outward relative to the vertical plane, and obtain D = D0 + 2tanθ; when calculating that the initial height H1 of the liquid in the ladle is equal to the ladle height H0, there is

[0036]

[0037] In the formula, M is the theoretical remaining mass of the molten steel in the ladle, and ρ is the density of the molten steel in the ladle.

[0038] It is stipulated that f is the variation function of the theoretical remaining mass M of the molten steel in the ladle and the theoretical real-time liquid level height H of the molten steel in the ladle, and let f = aH 3 + bH 2 + cH, H = H1, where Take θ = 1.5°, and stipulate that the density ρ of the common carbon steel molten steel is 7000 kg / m 3 , D0 = 3.61 m, so:

[0039] f = 5.02H 3 + 1038.91H 2 + 71611.39H

[0040] It can be obtained that:

[0041] H = f -1

[0042] In actual production, the mass and height of the ladle can be roughly regarded as a linear substitution, that is, it can be regarded as a cylinder. Substituting H1 = H, it can be obtained that:

[0043]

[0044] Given that the equipment belongs to the situation of quantitative liquid flow emptying, it is stipulated that A1 is the cross-sectional area of the water outlet, and A0 is the cross-sectional area of the ladle in the transverse direction. Then the mass flow rate of the water outlet is:

[0045]

[0046] In the formula, u is the instantaneous average flow velocity when the theoretical real-time liquid level height of the molten steel in the liquid outflow process is H. Then there is the formula:

[0047]

[0048] In the formula: ψ is the flow velocity coefficient of the water outlet. For example, the flow velocity coefficient of a cylindrical outer nozzle is 0.82, and g is the acceleration due to gravity;

[0049] When the mass flowing out per unit time is d M and the height of the liquid in the bucket drops by dH, there is the following relationship:

[0050] d M = -A0ρd H

[0051] It can be obtained that That is:

[0052]

[0053] It can be obtained that:

[0054]

[0055] It is stipulated that H 流出 is the height of the molten steel flowing out in the ladle, and H 流出 = H1 - H. Therefore, the height of the molten steel flowing out of the ladle at any time period can be obtained as:

[0056]

[0057] Then, the H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle and the theoretical outflow time t of the molten steel is established as:

[0058]

[0059] As a possible implementation solution, a water outlet is opened at the bottom of the ladle, and it is installed on the ladle turntable. A weighing body is arranged below the ladle, and the ladle is connected to the weighing body through a pressure-bearing head. A weighing sensor is connected below the pressure-bearing head to obtain the mass data of the molten steel in the ladle at different time periods. The method proposed by the present invention can directly judge the time when vortices are generated during the ladle pouring process by observing the change of the reading of the weighing sensor.

[0060] As a possible implementation solution, a sensor base is installed below the weighing sensor, which can fix the weighing sensor and protect its safety to prevent damage.

[0061] The second aspect of the present invention provides a ladle pouring method, including the following steps:

[0062] S1. Establish an M-H model between the theoretical remaining mass M of the molten steel in the ladle and the theoretical real-time liquid level height H of the molten steel: f(H)=M;

[0063] S2. Establish an H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle and the theoretical outflow time t of the molten steel:

[0064]

[0065] In the formula: H1 is the initial liquid level height of the molten steel in the ladle, ψ is the flow velocity coefficient of the water outlet (the flow velocity coefficient of a cylindrical outer nozzle is 0.82), g is the acceleration due to gravity, A0 is the cross-sectional area of the ladle bottom, and A1 is the cross-sectional area of the water outlet;

[0066] S3. According to the M-H model in step S1 and the H-t model in step S2, obtain the theoretical M-t model;

[0067] S4. When the ratio of the difference between the theoretical remaining mass M of the molten steel in the M-t model and the measured remaining mass of the molten steel to the theoretical remaining mass M of the molten steel reaches 10%, the theoretical outflow time of the molten steel at this time is the predicted time for slag entrainment phenomenon;

[0068] S5. Start the pouring operation, stop the pouring operation at the predicted time for slag entrainment phenomenon in step S4, stand still until the slag entrainment phenomenon ends, and then restart the pouring operation;

[0069] S6. Repeat step S5 until the pouring of the molten steel in the ladle is completed.

[0070] As a possible implementation solution, in step S1, the establishment process of the M-H model is as follows:

[0071] Measure the diameter of the bottom of the ladle as D0, the diameter of the top of the ladle as D, the initial liquid level height of the molten steel in the ladle as H1, the height of the ladle as H0, and the diameter of the molten steel liquid level in the ladle as D1, and obtain

[0072]

[0073] Therefore, the initial total volume V of the molten steel is:

[0074]

[0075] And the initial total mass M0 of the molten steel is:

[0076] M0 = ρV;

[0077] In the formula, ρ is the density of the molten steel;

[0078] In summary, there is

[0079]

[0080] That is, let: M0 = M, H1 = H;

[0081]

[0082] Then the M - H model is:

[0083]

[0084] As a possible implementation solution, in step S2, the establishment process of the H - t model is:

[0085] Measure the angle θ at which the side wall of the ladle is inclined outward relative to the vertical plane, and obtain D = D0 + 2tanθ; when calculating that the initial height H1 of the liquid in the ladle is equal to the height H0 of the ladle, there is

[0086]

[0087] In the formula, M is the theoretical remaining mass of the molten steel in the ladle, and ρ is the density of the molten steel in the ladle.

[0088] It is stipulated that f is the variation function of the theoretical remaining mass M of the molten steel in the ladle and the theoretical real - time liquid level height H of the molten steel in the ladle, and let f = aH 3 + bH 2 + cH, H = H1, where Take θ = 1.5°, and stipulate that the density ρ of ordinary carbon steel molten steel is 7000 kg / m 3 , D0 = 3.61 m, so:

[0089] f = 5.02H 3 + 1038.91H 2 + 71611.39H

[0090] It can be obtained that:

[0091] H = f -1

[0092] In actual production, the mass and height of the ladle can be approximately regarded as a linear substitution, that is, it can be regarded as a cylinder. Then it can be obtained that:

[0093]

[0094] Given that the equipment belongs to the case of quantitative liquid flow emptying, it is stipulated that A1 is the cross-sectional area of the water outlet, and A0 is the cross-sectional area of the ladle in the transverse direction. Then the mass flow rate of the water outlet is:

[0095]

[0096] In the formula, u is the instantaneous average flow velocity when the theoretical real-time liquid level height of the molten steel in the process of liquid outflow is H. Then there is a formula:

[0097]

[0098] In the formula: ψ is the flow velocity coefficient of the water outlet. For example, the flow velocity coefficient of a cylindrical outer nozzle is 0.82, and g is the acceleration due to gravity;

[0099] When the mass flowing out per unit time is d M and the height of the liquid in the bucket drops by dH, there is the following relationship:

[0100] d M =-A0ρd H

[0101] It can be obtained That is:

[0102]

[0103] From formula (8), it can be obtained that:

[0104]

[0105] It is stipulated that H 流出 is the height of the molten steel flowing out in the ladle, and H 流出 =H1 - H. Therefore, the height of the molten steel flowing out of the ladle at any time period can be obtained as:

[0106]

[0107] Then, the H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle and the theoretical outflow time t of the molten steel is established as:

[0108]

[0109] As a possible implementation solution, a water outlet is opened at the bottom of the ladle, and it is installed on the ladle turntable. A weighing body is arranged below the ladle, and the ladle is connected to the weighing body through a pressure-bearing head. A weighing sensor is connected below the pressure-bearing head to obtain the mass data of the molten steel in the ladle at different time periods. The method proposed by the present invention can directly judge the time when vortices are generated during the pouring process of the ladle by observing the change of the readings of the weighing sensor.

[0110] As a possible implementation solution, a sensor base is installed below the weighing sensor, which can fix the weighing sensor and also protect the safety of the weighing sensor to prevent damage.

[0111] In the case of adopting the above technical solution, in order to solve the problem that it is difficult to directly observe the slag absorption of the ladle leading to the decline of the purity of the molten steel in the existing technology, the present invention provides a method for collecting the mass change curve of the ladle, and then obtaining the specific time when the slag absorption phenomenon appears and stopping the pouring. It can realize obtaining the time when the slag absorption phenomenon appears in time, reduce the difficulty of detecting the slag absorption of the ladle, and improve the purity of the molten steel at the same time.

[0112] 3. Beneficial effects

[0113] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0114] The present invention uses the weighing sensor built in the ladle turntable to measure the remaining mass of the molten steel in the container and substitute it into the formula for calculation, thereby obtaining the equation of the mass of the molten steel in the ladle and the height of the molten steel, which simplifies the work process and is conducive to realizing mechanization and automation;

[0115] The present invention accurately judges the generation of vortices through data, thereby controlling the start and stop of pouring, and improving the purity of the molten steel;

[0116] The present invention is more accurate in judging the generation of vortices compared with the traditional method, and is more universal at the same time;

[0117] The present invention does not need to add additional devices or workload, and can be realized by obtaining data during the original pouring process. Description of the drawings

[0118] Figure 1 It is a schematic structural diagram of the ladle of the present invention;

[0119] Figure 2 It is a schematic structural diagram of the installation state of the ladle of the present invention;

[0120] Figure 3 It is a curve of the remaining mass of the molten steel and the outflow time in theory and in practice in Embodiment 1 of the present invention;

[0121] Figure 4The curves of the remaining mass of molten steel and the outflow time in theory and practice for Embodiment 2 of the present invention;

[0122] Reference numerals: 1, ladle; 11, water outlet; 2, molten steel; 3, weighing body; 31, bearing head; 32, weighing sensor; 33, sensor base. Detailed implementation manners

[0123] The present invention will be further described below in conjunction with specific embodiments.

[0124] To further understand the content of the present invention, the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0125] The structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they do not have technical essential meanings. Any modification of the structure, change of the ratio relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and the like cited in this specification are only for the convenience of clear narration and are not used to limit the scope of implementation. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope that the present invention can implement.

[0126] The present invention provides a method for predicting the time of slag entrainment phenomenon during ladle pouring and a ladle pouring method, and further obtains the specific time when the slag suction phenomenon appears and stops pouring, and realizes the equipment of the present invention such as Figures 1 - 2 As shown: a water outlet 11 is opened at the bottom of the ladle 1 and installed on the ladle turntable. A weighing body 3 is arranged below the ladle 1. The ladle 1 and the weighing body 3 are connected through a bearing head 31. A weighing sensor 32 is connected below the bearing head 31 to obtain the mass data of the molten steel 2 in the ladle 1 at different time periods; a sensor base 33 is installed below the weighing sensor 32, which can fix the weighing sensor 32 and also protect the safety of the weighing sensor 32 to prevent damage.

[0127] The application and principle of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0128] Embodiment 1

[0129] In the laboratory, the water model is used to simulate the emptying of molten steel from the ladle 1 by a similar principle. The model is a cylindrical container with a diameter of 20 cm and a water outlet diameter of 20 mm;

[0130] Add normal temperature water with a height of 30 cm to the cylindrical container, calculate that the mass of the water is about 9450 g, participate in the experiment and record the data;

[0131] Furthermore, combine the M-H model with the H-t model between the theoretical liquid level height H and the theoretical molten steel outflow time t in the water model:

[0132]

[0133] Furthermore, obtain the theoretical M-t model:

[0134] M 剩余 = 9450 - 419.88t + 4.51t 2

[0135] Plot the theoretical M-t model and the actual M-t curve, as Figure 3 shown. Through long-term static placement, obtain the situation without initial rotation intensity, and record the slag entrainment curve without vortex through the load cell;

[0136] Similarly, by rotating the cylindrical container for a long time, obtain the situation with a large initial rotation intensity, and record the slag entrainment curve with vortex through the load cell;

[0137] From Figure 3 it can be seen that the two curves coincide before 8.2 s, indicating that their pouring curves are basically the same before the generation of vortex. After 8.2 s, the slope of the slag entrainment curve without vortex is the same as that of the curve before 8.2 s, and the mass reduction rate in ladle 1 remains unchanged; while the slag entrainment curve with vortex has an obvious inflection point after 8.2 s, and the slope is significantly lower than that before 8.2 s; Therefore, it can be judged that the time for the container to generate vortex is about 8.2 s under this rotation condition;

[0138] From this situation, it can be known that this method can effectively and accurately judge the time of vortex generation during the pouring process of ladle 1 through the curve change diagram drawn by the load cell.

[0139] Example 2

[0140] As Figure 1 shown, the molten steel 2 is stored in the ladle 1. Take a 210 t ladle as the ladle 1 used in the specific implementation to explore whether the method of judging the slag entrainment time by directly observing the data is feasible. Among them:

[0141] Table 1. 210 t ladle data

[0142] Top diameter D <![CDATA[Bottom diameter D0]]> Liquid level height H <![CDATA[Ladle height H0]]> 3.86 3.61 2.9 4.25

[0143] From the data in Table 1, it can be known that D0 = 3.61 m, D = 3.86 m, H0 = 4.25 m, H = 2.9 m;

[0144] The weighing sensor 33 installed inside the ladle 1 is connected to a computer, and the data in Table 1 is imported into the computer to obtain the M-H model between the theoretical remaining mass M of the molten steel in the ladle 1 and the theoretical real-time liquid level height H of the molten steel;

[0145] Furthermore, the M-H model is combined with the H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle 1 and the theoretical outflow time t of the molten steel:

[0146]

[0147] The theoretical M-t model is obtained:

[0148] M 剩余 = 210 - 2.9t + 0.01t 2

[0149] The theoretical M-t model and the actual M-t curve are plotted. Figure 4 It can be seen that the two curves coincide before 15s, indicating that their pouring curves are basically the same before the vortex is generated. After 15s, the curve without vortex slag entrainment has the same slope as the curve before 15s, and the mass reduction rate of the ladle 1 remains unchanged; while the curve with vortex slag entrainment has an obvious inflection point after 15s, and the slope is significantly lower than that before 15s; Therefore, it can be judged that under this rotation condition, the time when the vortex is generated in the container is about 15s;

[0150] The actual situation of the molten steel is similar to that of the water model. When the molten steel in the ladle 1 drops to a certain extent, due to the existence of the initial disturbance, a vortex appears in the liquid inside the ladle 1. Furthermore, it can be observed through the weighing sensor curve that when the weighing curve of the ladle 1 has an inflection point, it can be concluded from this phenomenon that vortex slag entrainment occurs inside the ladle 1 at this time;

[0151] Furthermore, it is known that the mass of the molten steel in the ladle 1 is certain in actual production, and the weighing sensor can obtain the remaining mass of the molten steel. Then, by substituting into the equation of mass and height, the remaining molten steel height when vortex slag entrainment occurs can be calculated;

[0152] Furthermore, when the weighing curve of the ladle 1 has an inflection point, all sliding nozzles are closed and the pouring of the ladle 1 is stopped, so as to effectively prevent slag entrainment in the ladle 1.

[0153] The above is only the preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention or direct application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A method for predicting the time of slag entrainment phenomenon during ladle pouring, characterized in that: The steps are as follows: S1. Establish an M-H model between the theoretical remaining mass M of the molten steel in the ladle and the theoretical real-time liquid level height H of the molten steel: f(H) = M; S2. Establish an H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle and the theoretical outflow time t of the molten steel: Where: H1 is the initial liquid level height of the molten steel in the ladle, ψ is the flow velocity coefficient of the water outlet (the flow velocity coefficient of a cylindrical external nozzle is 0.82), g is the acceleration due to gravity, A0 is the cross-sectional area of the ladle bottom, and A1 is the cross-sectional area of the water outlet; S3. Obtain a theoretical M-t model based on the M-H model in step S1 and the H-t model in step S2; S4. When the ratio of the difference between the theoretical remaining mass M of the molten steel and the measured remaining mass of the molten steel in the M-t model to the theoretical remaining mass M of the molten steel reaches 10%, the theoretical outflow time of the molten steel at this time is the time predicted to generate slag entrainment.

2. The method for predicting the time of slag entrainment phenomenon during ladle casting according to claim 1, wherein: In step S1, the establishment process of the M-H model is as follows: Measure the diameter of the ladle bottom as D0, the diameter of the ladle top as D, the initial liquid level height of the molten steel in the ladle as H1, the height of the ladle as H0, the diameter of the molten steel liquid level in the ladle as D1, and the density of the molten steel as ρ. The initial total volume V of the molten steel is: The initial total mass M0 of the molten steel is: M0 = ρV; Let: M0 = M, H1 = H; The obtained M-H model is:

3. The method for predicting the time of slag entrainment phenomenon in ladle pouring according to claim 2, wherein: In step S2, the establishment process of the H-t model is as follows: Measure the angle θ of the ladle side wall inclined outward relative to the vertical plane, and obtain D = D0 + 2tanθ; when calculating that the initial height H1 of the liquid in the ladle is equal to the height H0 of the ladle, there is Where M is the theoretical remaining mass of the molten steel in the ladle and ρ is the density of the molten steel in the ladle; In actual production, the mass and height of the ladle can be roughly regarded as a linear substitution. Substituting H1 = H, we can get: It is stipulated that A1 is the cross-sectional area of the water outlet and A0 is the cross-sectional area of the ladle in the transverse direction. Then the mass flow rate of the water outlet is: Where u is the instantaneous average flow velocity when the theoretical real-time liquid level height of the molten steel is H during the liquid outflow process. Then there is the formula: Where: ψ is the flow velocity coefficient of the water outlet and g is the acceleration due to gravity; When the outflow mass is d within unit time M and the liquid level in the bucket drops by dH, the following relationship holds: d M = -A0ρd H It can be obtained Obtain: We can get: Regulation H 流出 is the height of the molten steel flowing out of the ladle, and H 流出 = H1 - H, so the height of the molten steel flowing out of the ladle at any time period can be obtained as follows: Then, the established H-t model between the theoretical real-time liquid level height H of the molten steel in the ladle and the theoretical outflow time t of the molten steel is:

4. The method for predicting the time of slag entrainment phenomenon during ladle casting according to claim 3, wherein: Measure the ladle. The diameter D0 at the bottom of the ladle is 3.61 m, the diameter D at the top of the ladle is 3.86 m, the initial liquid level height H1 of the molten steel in the ladle is 2.9 m, the ladle height H0 is 4.25 m, and the density ρ of the molten steel is 7000 kg / m 3 , θ = 1.5°, the velocity coefficient ψ of the water outlet is 0.82, the diameter d of the water outlet is 0.3 m, and the theoretical M-t model is: M = 210 - 2.9t + 0.01t 2 .

5. The method for predicting the time of slag entrainment phenomenon during ladle casting according to any one of claims 1 to 4, characterized in that: A water outlet is opened at the bottom of the ladle and installed on the ladle turntable. A weighing body is arranged below the ladle. The ladle is connected to the weighing body through a pressure head, and a weighing sensor is connected below the pressure head to obtain the mass data of the molten steel in the ladle at different time periods.

6. The method for predicting the time of slag entrainment phenomenon in ladle pouring according to claim 5, wherein: A sensor base is installed below the weighing sensor.

7. A ladle casting method, characterized in that: Adopt the method of any one of claims 1 to 6 to predict the time of slag entrainment. Start the pouring operation, stop the pouring operation when the time of predicted slag entrainment is reached, wait until the slag entrainment phenomenon ends, and then restart the pouring operation; Obtain the time of predicted slag entrainment for the next time, stop pouring, and repeat the above steps until the pouring of the molten steel in the ladle is completed.

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