Molten steel treatment mechanism and treatment mode capable of prolonging bubble retention time

Abstract

The invention provides a molten steel treatment mechanism and a molten steel treatment mode capable of prolonging the retention time of bubbles. The molten steel treatment mechanism comprises a steel ladle, wherein the steel ladle is provided with an accommodating cavity for accommodating molten steel; the blowing mechanism communicates with the containing cavity. The electromagnetic stirrer is arranged at the bottom of the steel ladle and comprises a plurality of windings, and the windings form two winding parts which are distributed in a central symmetry mode in the same plane. The ratio of the diameter of the first circular arc corresponding to the outer contours of the two winding parts to the inner diameter of the bottom of the steel ladle is (1460-1500): (2540-2640); and the ratio of the diameter of the second circular arc corresponding to the inner contours of the two winding parts to the inner diameter of the bottom of the steel ladle is (1100-1140): (2540-2640). According to the molten steel treatment mechanism, the retention time of the bubbles generated by the blowing mechanism in the molten steel is prolonged, and the stirring effect of the bubbles is fully utilized, so that the stirring efficiency is greatly improved, and the stirring time required by alloy is shortened.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a molten steel treatment mechanism and a treatment method for increasing the residence time of bubbles. Background Art

[0002] The electromagnetic stirrer is installed in the ladle to stir the molten steel in the ladle so that the molten steel can be stirred quickly and evenly. The main advantage of electromagnetic stirring is that the electromagnetic force and stirring state can be adjusted by adjusting the various parameters of the stirrer. For example, the stirring direction can be changed at any time, and the stirring intensity can be changed and adjusted at will. This is an advantage that cannot be replaced by other stirring methods (especially permanent magnetic stirring). Moreover, the low-frequency traveling wave magnetic field generated by the electromagnetic stirrer penetrates the furnace shell and lining into the molten pool to ensure that the slag layer is not damaged and prevent secondary oxidation of the molten steel.

[0003] However, current electromagnetic stirrers require a long time to evenly mix the molten steel. Summary of the invention

[0004] The main purpose of the present invention is to provide a molten steel treatment mechanism and treatment method for increasing the bubble residence time, so as to solve the technical problem that an electromagnetic stirrer needs a long time to mix the molten steel evenly.

[0005] To achieve the above object, the present invention provides a molten steel treatment mechanism for increasing the bubble residence time, comprising:

[0006] A ladle having a holding chamber for holding molten steel;

[0007] An air blowing mechanism, connected to the accommodating cavity;

[0008] An electromagnetic stirrer is arranged at the bottom of the ladle, and the electromagnetic stirrer comprises a plurality of windings, wherein the plurality of windings form two winding parts which are centrally symmetrically distributed in the same plane;

[0009] The ratio of the diameter of the first arc corresponding to the outer contour of the two winding parts to the bottom inner diameter of the ladle is (1460~1500):(2540~2640); the ratio of the diameter of the second arc corresponding to the inner contour of the two winding parts to the bottom inner diameter of the ladle is (1100~1140):(2540~2640); the number of windings in any one of the winding parts is 3~6, ​​and the angle of any one of the winding parts relative to the center of the first arc is 60-120°.

[0010] According to an implementation manner of the present application, within any of the winding sections, all the windings are equally spaced, and the ratio of the length, width and height of the windings is (580-800):(250-400):(300-450); the ratio of the height of the winding to the height of the ladle is (200-400):(2500-4000).

[0011] According to an embodiment of the present application, in any of the winding parts, there is a core seat and a core body arranged on the core seat, the core body is arranged corresponding to the winding, and the winding is respectively wound on the core body; the ratio of the height of the core seat to the height of the core body is 100:290.

[0012] According to an embodiment of the present application, the number of turns of the coil of the winding is 90 to 110, and the diameter of the wire in the coil is 8 to 18 mm.

[0013] According to an embodiment of the present application, the distance between the top of the winding and the outer side of the bottom of the ladle is 8 to 12 mm.

[0014] According to an embodiment of the present application, the blowing mechanism is connected to the blowing hole at the bottom of the ladle, and the blowing hole is located at 1 / 2R-2 / 3R of the bottom of the ladle, where R is the radius of the bottom of the ladle.

[0015] According to an embodiment of the present application, the bottom of the ladle has air-permeable bricks, and the radius of the air-permeable bricks is 0.08 to 0.12 meters.

[0016] The present application also provides a method for treating molten steel, wherein the molten steel is added into the above-mentioned molten steel treatment mechanism for treatment.

[0017] According to the implementation of the present application, argon gas is introduced into the molten steel in the ladle through a blowing mechanism at a flow rate of 400 to 2000 L / min and a pressure of 0.3 to 1.3 MPa, and the electromagnetic stirrer is operated at an AC current intensity of 200A to 400A.

[0018] According to an embodiment of the present application, the argon gas is introduced into the molten steel in the ladle at a flow rate of 600-1000 L / min and a pressure of 0.45-07 MPa, and the electromagnetic stirrer is operated at a current intensity of 200A-400A.

[0019] In the above-mentioned molten steel processing mechanism, the agitator coil adopts a centralized winding, and the arrangement of the winding is controlled to cooperate with the blowing mechanism, which prolongs the residence time of the bubbles generated by the blowing mechanism in the molten steel and fully utilizes the stirring effect of the bubbles. In this way, the stirring efficiency is greatly improved, thereby shortening the stirring time required for the alloy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0021] Figure 1 It is a structural schematic diagram of a molten steel treatment mechanism according to an embodiment of the present application;

[0022] Figure 2 This is a diagram of electromagnetic force distribution in a cross section of an electromagnetic stirrer Z=0.05m according to an embodiment of the present application;

[0023] Figure 3 This is a distribution diagram of the main strands of molten steel in a cross section of Z=0.05m under the action of an electromagnetic stirrer according to an embodiment of the present application;

[0024] Figure 4 This is a bubble movement distribution diagram of an embodiment of the present application when the argon blowing flow rate is 200L / min and the current intensity is 400A at 100, 200, 300 and 400s;

[0025] Figure 5 is a graph of average bubble residence time of different bubble sizes under an agitator according to an embodiment of the present application;

[0026] Figure 6 is a graph of average bubble residence time of different bubble sizes without an electromagnetic stirrer in Comparative Example 1 of the present application;

[0027] Figure 7 It is a schematic diagram of the side electromagnetic stirrer of Comparative Example 2 of the present application;

[0028] Figure 8 This is a graph of average bubble residence time of different bubble sizes of the side electromagnetic stirrer of Comparative Example 2 of the present application;

[0029] Fig. 9 It is a schematic diagram of the structure of a winding according to an embodiment of the present application.

[0030] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings.

[0031] Description of reference numerals:

[0032] 100, ladle; 200, electromagnetic stirrer; 20, winding part; 210, winding; 211, core seat; 212, core body; 213, coil. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be noted that all directional indications (such as up, down, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0035] In addition, in the present invention, the descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0036] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0037] The present invention provides a molten steel treatment mechanism, referring to Figure 1 and Fig. 9 , comprising a ladle 100, a blowing mechanism and an electromagnetic stirrer 200. The ladle 100 has a containing chamber for containing molten steel. The blowing mechanism is connected to the containing chamber. The electromagnetic stirrer 200 is arranged at the bottom of the ladle 100, and the electromagnetic stirrer 200 comprises a plurality of windings 210, and the plurality of windings 210 form two winding parts 20 which are centrally symmetrically distributed in the same plane. The ratio of the diameter of the first circular arc corresponding to the outer contour of the two winding parts 20 to the bottom inner diameter of the ladle 100 is (1460~1500):(2540~2640); the ratio of the diameter of the second circular arc corresponding to the inner contour of the two winding parts 20 to the bottom inner diameter of the ladle 100 is (1100~1140):(2540~2640).

[0038] The plurality of windings 210 are evenly distributed, and the whole is a concentrated winding 210. Therefore, each winding portion 20 is in an arc-shaped strip shape, and its inner contour and outer contour are both arc-shaped.

[0039] The diameter of the first arc corresponds to the outer diameter of the stirrer. The diameter of the second arc corresponds to the inner diameter of the stirrer. In some embodiments, the outer diameter of the stirrer is 680 mm. The inner diameter of the stirrer is 320 mm. The bottom inner diameter of the ladle 100 is 2600 mm.

[0040] The number of the windings 210 in any winding portion 20 is 3 to 6, and the angle of any winding portion 20 relative to the center of the first arc is 60-120°. Exemplarily, the number of the windings 210 in each winding portion 20 is 6.

[0041] Under the condition of satisfying the above conditions with the bottom inner diameter of the ladle 100, the stirring area of ​​the electromagnetic stirrer 200 can basically cover all areas of the ladle 100 in the axial section. The electromagnetic stirrer 200 of this type generates a rotating magnetic pole, that is, a rotating magnetic field. The rotating magnetic field is stationary, but the direction of the magnetic field changes in a rotating state in space over time. In this way, the molten steel also rotates in the ladle 100.

[0042] In the above-mentioned molten steel processing mechanism, the agitator coil 213 adopts a centralized winding 210. The arrangement of the winding 210 is controlled to cooperate with the blowing mechanism, which prolongs the residence time of the bubbles generated by the blowing mechanism in the molten steel and fully utilizes the stirring effect of the bubbles. In this way, the stirring efficiency is greatly improved, thereby shortening the stirring time required for the alloy.

[0043] In some embodiments, reference Fig. 9 In any of the winding parts 20, all the windings 210 are evenly spaced, and the ratio of the length, width and height of the winding 210 is (580-800): (250-400): (300-450); the ratio of the height of the winding 210 to the height of the ladle 100 is (200-400): (2500-4000).

[0044] The height of the winding 210 corresponds to the height of the coil 213 of the stirrer.

[0045] In some embodiments, in any of the winding parts 20 , there is a core seat 211 and a core body 212 disposed on the core seat 211 , the core body 212 is disposed corresponding to the winding 210 , and the winding 210 is respectively wound on the core body 212 .

[0046] In some embodiments, the ratio of the height of the core seat 211 to the height of the core body 212 is 100:290.

[0047] The height of the core body 212 is the height of the coil 213 of the stirrer, and the height of the stirrer is the sum of the height of the core seat 211 and the height of the core body 212. For example, the height of the core seat 211 is 100 mm, and the height of the core body 212 is 290 mm.

[0048] In some embodiments, the number of turns of the coil 213 of the winding 210 is 90 to 110, and the diameter of the wire in the coil 213 is 8 to 18 mm.

[0049] Exemplarily, the number of turns of the coil 213 of the winding 210 is 100 turns.

[0050] In some embodiments, the blowing mechanism is connected to the blowing hole at the bottom of the ladle 100 , and the blowing hole is located at 1 / 2R-2 / 3R of the bottom of the ladle 100 , where R is the radius of the bottom of the ladle 100 .

[0051] In some embodiments, the bottom of the ladle 100 has a permeable brick, and the radius of the permeable brick is 0.08 to 0.12 meters.

[0052] The present application also discloses a method for treating molten steel, wherein the molten steel is added into the above-mentioned molten steel treatment mechanism for treatment.

[0053] The applicant described the electromagnetic force generated by the electromagnetic stirrer and calculated the coupling magnetic field to obtain an electromagnetic stirrer with a longer bubble residence time. Specifically, the electromagnetic force is mainly used to rotate the molten steel, disperse the main stream of bubbles and extend the distance that the bubbles move up, thereby extending the bubble residence time.

[0054] Each bubble entering the molten steel is tracked by the DPM model in FLUENT of ANSYS commercial simulation software. The bubble residence time is the difference between the time when the bubble overflows the molten steel and the time when the bubble enters the molten steel. At least 4,000 bubbles are collected as a sample library, and their arithmetic mean is taken as the average residence time. The calculation results show that the residence time of bubbles with different diameters increases.

[0055] Maxwell's equations are the basis for studying macroscopic electromagnetic problems and the basis for finite element analysis of electromagnetic problems. Therefore, the analysis of electromagnetic problems is actually solving Maxwell's equations under boundary conditions. Maxwell's equations consist of four laws: Gauss's flux law, Gauss's law, Faraday's law of electromagnetic induction, and Ampere's circuit law.

[0056] The current passing through the coil is a harmonic current, and the magnetic field generated is a harmonic magnetic field. The electromagnetic field formed by the electromagnetic stirrer satisfies the following simplified Maxwell equations:

[0057]

[0058] In the formula, H is the magnetic induction intensity, A / m; j is the current density, A / m2; t is the time, s; B is the magnetic induction intensity, T; E is the electromagnetic intensity, V / m.

[0059] The above results show that the electromagnetic fields at each point in space are interrelated. By solving differential equations, the electromagnetic field distribution of practical problems can be calculated. In practical applications, the influence of the medium on the magnetic field must be considered. For isotropic media:

[0060] B=μ0μ r H (5)

[0061] In the formula, μr is the relative magnetic permeability, dimensionless; μ0 is the vacuum magnetic permeability, 4π×10-7.

[0062] Calculation of electromagnetic force

[0063] The induced current in the molten steel in the electromagnetic field can be expressed as:

[0064] j=σ(E+u i ×B) (6)

[0065] Where σ is the conductivity, S / m.

[0066] The generated electromagnetic force can be expressed as:

[0067] F=j×B (7)

[0068] Combining formulas (3), (4), (5) and (7), we can get the following equation:

[0069]

[0070] In the formula, the first term on the right side of the formula is the magnetic convection term, and the second term is the magnetic diffusion term. The magnetic Reynolds number can be defined as:

[0071] Re m =u i Lσμ0μ r (9)

[0072] Where F is the electromagnetic force, N / m 3 ; L is the characteristic length of the molten pool, m. Usually when Re m >>1, the fluid flow has a greater impact on the magnetic field and cannot be ignored; m When <<1, the fluid flow has little effect on the magnetic field and can be ignored. The magnetic field frequency involved in this study is 10Hz (the magnetic field frequency is set in the simulation software, and the electromagnetic stirrer itself can adjust this parameter in the range of 0-20Hz) to meet Re m<<1. Therefore, in this study, the effect of fluid flow on the magnetic field is ignored. According to the Euler-Lagrange model, liquid steel is the continuous phase and argon is the discrete phase. Liquid steel is an incompressible fluid, and the continuity equation and momentum conservation equation of liquid steel are simplified as follows:

[0073]

[0074] In the formula, u i is the fluid velocity, m / s; ρ is the density of the molten steel, kg / m 3 ; P is pressure, Pa; μ e is the effective turbulent viscosity, μ t is the turbulent viscosity, kg / (m·s); μ is the viscosity of the molten steel, kg / (m·s); F lg，i is the interaction force between liquid and gas phase, N / m 3 ;x i and x j They represent the components of the vector in different directions.

[0075] Basic equation of temperature field transmission:

[0076]

[0077] In the formula, C p is the specific heat capacity of molten steel, J / (kg·K); λ is the thermal conductivity of molten steel, W / (m·K); T is the temperature of molten steel, K.

[0078] Basic equations for component transport:

[0079]

[0080] In the formula, C M is the alloy mass concentration, kg / m 3 ;D M is the turbulent diffusion coefficient, m 2 / s;S Ct is the Schmidt number, which takes a value of 0.7.

[0081] The turbulence is solved using the standard two-equation k-ε model:

[0082] Turbulent kinetic energy k equation:

[0083]

[0084] The turbulent kinetic energy dissipation rate ε equation:

[0085]

[0086] In the formula, C 1ε , C 2ε, C μ , σ k , σ ε is an empirical constant, and its values ​​are 1.44, 1.92, 0.09, 1.0, and 1.3 respectively; G k is the turbulent kinetic energy generated by the mean velocity gradient.

[0087] In the Lagrangian coordinate system, ANSYS Fluent regards the argon bubbles injected at the bottom inlet as discrete phases and predicts the motion trajectory of the bubbles by integrating the force balance on the particles. The inertial force of the particles and the force acting on the particles constitute a force balance, which can be written as:

[0088]

[0089] In the formula, u bi is the bubble velocity, m / s. The terms on the right side of the equal sign represent drag, lift, pressure gradient force, virtual mass force, gravity, and buoyancy. [55-56] . The various model equations are expressed as follows:

[0090]

[0091] In the formula, ρ b is the bubble density, kg / m 3 ; C d is the drag coefficient; Re is the relative Reynolds number; We is the Weber number; d b is the bubble particle size, m; σ 1b is the surface tension between the molten steel and the bubbles, N / m; C v is the virtual mass coefficient, g i is the acceleration due to gravity, m / s 2 .

[0092]

[0093] Where P R is the relative probability; P m is the maximum relative probability; is the maximum particle size of bubbles in the molten steel, m; s is the standard deviation, which is 0.026m; is the maximum particle size of the bubble distribution measured under Wood's alloy, m; for 50%

[57] .

[0094]

[0095] The particle size and density are calculated iteratively, using the previous state of each bubble to calculate the next state. Due to the low temperature difference in the ladle, this paper does not consider the effect of temperature change on bubble growth. The initial bubble particle size is determined by the initial temperature of the molten steel.

[0096] In some embodiments, argon gas is introduced into the molten steel in the ladle through a blowing mechanism at a flow rate of 400-2000 L / min and a pressure of 0.3-1.3 MPa, and the electromagnetic stirrer is operated at an AC current intensity of 200A-400A.

[0097] Under this condition, the bubble residence time is greatly extended, and the stirring effect of the bubbles is fully utilized, so the stirring efficiency is greatly improved, thereby shortening the stirring time required for the alloy.

[0098] In some specific embodiments, the argon gas is introduced into the molten steel in the ladle at a flow rate of 600-1000 L / min and a pressure of 0.45-07 MPa, and the electromagnetic stirrer is operated at a current intensity of 200A-400A.

[0099] The technical solution of the present application is described below with a specific embodiment.

[0100] Example 1

[0101] The electromagnetic stirrer established in this patent belongs to the rotary electromagnetic stirring stirrer. The stirrer coil adopts centralized winding, and the structural dimensions of the stirrer are consistent with those shown in Table 1. The model structure of the ladle and the electromagnetic stirrer is as follows Figure 1 shown.

[0102] Table 1 Physical properties

[0103]

[0104] To facilitate calculation and simulation, the simulation is appropriately simplified and the following basic assumptions are made:

[0105] (1) Ignore the Joule heat generated by the electromagnetic stirrer.

[0106] (2) Ignoring the influence of slag, the molten steel is in direct contact with the atmosphere.

[0107] (3) The physical properties of molten steel, such as density, viscosity, electrical conductivity and magnetic permeability, are constants.

[0108] (4) Ignore the effect of temperature gradient in molten steel on bubble diameter.

[0109] (5) The ladle is filled with stationary molten steel.

[0110] Study on electromagnetic force distribution

[0111] Among them, the inventors studied the distribution of electromagnetic force formed at the bottom of molten steel when the electromagnetic stirrer had a current intensity of 200A to 400A.

[0112] Figure 2 The electromagnetic force distribution diagram of the electromagnetic stirrer at the bottom of the molten steel when the current intensity is 200 A. The electromagnetic force in the figure consists of two parts, the upper part of the electromagnetic force points to the negative direction of the X-axis, and the lower part points to the positive direction of the X-axis. The two parts of the electromagnetic force act together on the molten steel to make the molten steel rotate and flow.

[0113] Flow field distribution under the action of electromagnetic stirrer

[0114] The molten steel at the bottom forms a counterclockwise rotation with the center of the bottom of the ladle as the center. As the current intensity increases, the speed of the molten steel gradually increases, and the speed distribution is basically consistent with the distribution of the electromagnetic stirrer. Figure 3 , Figure 3 This is the distribution diagram of the main stream of molten steel in the Z=0.05m section under the action of the electromagnetic stirrer.

[0115] Bubble distribution under electromagnetic stirrer

[0116] Figure 4 The argon blowing flow rate is 200L / min, the current intensity is 400A at 100, 200, 300

[0117] The bubbles are distributed discretely near the liquid surface, which is the result of the agitator rotating the molten steel.

[0118] Bubble residence time under electromagnetic stirrer

[0119] Figure 5 The average residence time of bubbles of different sizes in the molten steel at a current intensity of 400A and a flow rate of 200L / min. The average residence time of 1mm bubbles is 6.90s. The average residence time difference between the smallest diameter 1mm bubble and the diameter 40mm bubble is 2.24s. The average residence time of 1mm bubbles is extended by 4.37s compared to the case without electromagnetic stirring.

[0120] Comparative Example 1 Bubble Residence Time without Electromagnetic Stirrer

[0121] Figure 6 The average residence time of bubbles of different sizes in the molten steel at a flow rate of 200L / min without an electromagnetic stirrer. The average residence time of 1mm bubbles is 2.53s, and the average residence time of bubbles in the diameter range of 1-10mm decreases significantly. The average residence time in the range of 10-40mm decreases slowly, basically remaining at around 2.3s.

[0122] Comparative Example 2 Bubble residence time under the side electromagnetic stirrer

[0123] The stirrer coil simulated in Example 2 adopts a concentrated winding, and the structural dimensions of the stirrer are consistent with those shown in Table 2. The model structure of the ladle and the electromagnetic stirrer is shown in Figure 7 shown.

[0124] Table 2 Physical properties

[0125]

[0126] Figure 8 The average residence time of bubbles of different sizes in the molten steel under the condition of a side electromagnetic stirrer flow rate of 200L / min. The average residence time of 1mm bubbles is 2.79s, and the average residence time of 40mm bubbles is 2.37s. The average residence time of bubbles with a particle size of 1-10mm decreases rapidly, and the difference between the average residence time of 1mm bubbles and the average residence time of 10mm bubbles is 0.3s. The average residence time of bubbles with a particle size of 10-40mm tends to be stable, and the difference between the average residence time of 10mm bubbles and the average residence time of 40mm bubbles is 0.12s.

[0127] Analysis example

[0128] This patent describes the electromagnetic force formed by the electromagnetic stirrer and couples the magnetic field with the flow field of the eccentric bottom-blown ladle for calculation. By comparing the magnetic field distribution, flow field distribution, and average bubble residence time in the ladle, the following conclusions are drawn: Compared with the control group without the use of the rotary electromagnetic stirrer mentioned in this patent, the average residence time of 1mm bubbles can be increased by 4.5s, the residence time of 10mm bubbles can be increased by 3.7s, the residence time of 20mm bubbles can be increased by 3.2s, the residence time of 30mm bubbles can be increased by 2.9s, and the residence time of 40mm bubbles can be increased by 2.3s. Bottom electromagnetic stirring can significantly prolong the residence time of bubbles in molten steel compared with side electromagnetic stirring. Therefore, the rotary electromagnetic stirrer in this patent is very effective.

[0129] The above technical solutions of the present invention are only preferred embodiments of the present invention, and the patent scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A molten steel treatment mechanism for increasing bubble residence time, characterized in that: include: A ladle having a holding chamber for holding molten steel; An air blowing mechanism, connected to the accommodating cavity; An electromagnetic stirrer is arranged at the bottom of the ladle, and the electromagnetic stirrer comprises a plurality of windings, wherein the plurality of windings form two winding parts which are centrally symmetrically distributed in the same plane; The ratio of the diameter of the first arc corresponding to the outer contour of the two winding parts to the bottom inner diameter of the ladle is (1460~1500):(2540~2640); the ratio of the diameter of the second arc corresponding to the inner contour of the two winding parts to the bottom inner diameter of the ladle is (1100~1140):(2540~2640); the number of windings in any one of the winding parts is 3~6, ​​and the angle of any one of the winding parts relative to the center of the first arc is 60-120°.

2. The molten steel processing mechanism according to claim 1, characterized in that: In any of the winding sections, all the windings are equally spaced, and the ratio of the length, width and height of the windings is (580-800):(250-400):(300-450); the ratio of the height of the winding to the height of the ladle is (200-400):(2500-4000).

3. The molten steel processing mechanism according to claim 1, characterized in that: In any of the winding parts, there are an iron core seat and an iron core body arranged on the iron core seat, the iron core body is arranged corresponding to the winding, and the winding is respectively wound on the iron core body; the ratio of the height of the iron core seat to the height of the iron core body is 100:

290.

4. The molten steel processing mechanism according to claim 3, characterized in that: The number of turns of the coil of the winding is 90 to 110, and the diameter of the wire in the coil is 8 to 18 mm.

5. The molten steel processing mechanism according to claim 3, characterized in that: The distance between the top of the winding and the outer side of the bottom of the ladle is 8 to 12 mm.

6. The molten steel processing mechanism according to claim 1, characterized in that: The blowing mechanism is connected to the blowing hole at the bottom of the ladle, and the blowing hole is located at 1 / 2R-2 / 3R of the bottom of the ladle, where R is the radius of the bottom of the ladle.

7. The molten steel processing mechanism according to claim 1, characterized in that: The bottom of the ladle is provided with air-permeable bricks, and the radius of the air-permeable bricks is 0.08 to 0.12 meters.

8. A method for treating molten steel, characterized in that: The molten steel is added into the molten steel treatment mechanism as described in any one of claims 1 to 7 for treatment.

9. The processing method according to claim 8, characterized in that: Argon gas is introduced into the molten steel in the ladle at a flow rate of 400-2000 L / min and a pressure of 0.3-1.3 MPa through a blowing mechanism, and an electromagnetic stirrer is operated at an AC current intensity of 200A-400A.

10. The processing method according to claim 9, characterized in that: The argon gas is introduced into the molten steel in the ladle at a flow rate of 600-1000 L / min and a pressure of 0.45-07 MPa, and the electromagnetic stirrer is operated at a current intensity of 200A-400A.

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