CN100421838C - Systems and methods of electromagnetic influence on electroconducting continuum - Google Patents

Abstract

Thus, as shown by an exact electrodynamic computation of EMBF and the estimations described above of the velocity of turbulent flows arising due to their effect, application of amplitude- and frequency-modulated helically traveling (rotating and axially traveling) electromagnetic fields in metallurgical and chemical technologies and foundry can considerably increase the hydraulic efficiency of MHD facilities, intensify the processes of heat and mass transfer in technological plants, significantly increase their productivity, considerably decrease energy consumption for the production of metals, alloys, cast articles, and chemical products, and improve their quality.

Description

The method of the crystal structure of control class ferrous metal and non-ferrous ingot and ingot casting

Quoting mutually of related application

The application requires the priority of No. 60/517,359, the U.S. Provisional Patent Application of No. 60/434,230, the U.S. Provisional Patent Application of on December 16th, 2002 application and application on November 4th, 2003.

Technical field

Electromagnetism on the relate generally to conducting medium of the present invention is forced impact method, and relates in particular to the method for the dark reinforcement that can be applicable to metallurgical process.

Background technology

The method of utilizing magnetic field that rotate, that move or that spiral moves to force to influence conducting medium is known and enough is widely used for strengthening various metallurgical processes, the crystallization of for example fusing, alloying, objectionable impurities purification, continuous metal ingot and casting or the like.But, can obviously improve metallurgical process grade and the end product quality that utilizes these known methods to obtain by the method for utilizing this proposition.

Know method (the following patent: K ü rt (No. 307225, Deutsche Bundespatent of utilizing rotation or shifting magnetic field to control the crystal structure of continuous fixing metal ingot and ingot casting for a long time, 1917), Jungans and Schaber (No. 911425, FRG patent, 1954), (United States Patent (USP) 2,963, No. 758 such as Pestel, 1960), they respectively include conduct on the whole with reference to data).The test material that accumulates in this field shows, applies ingot and ingot casting that magnetic field rotation or that move eliminates the column structure of cast product and can produce axle particulate close packed structures such as having, this their engineering properties of structure positive influences.But the turbulent flow grade in the liquid metal that conventional method obtains has limited the scope that applies magnetohydrodynamics (MHD) effect in metallurgical process.

Thereby the validity that obviously improves the influence of MHD method on the crystallization process melt is a quite urgent problem.

In association area, in the facility of setting up for this purpose, there is a kind of known method of in by the rotary magnetic field of unmodulated three-phase current excitation, handling molten cast iron continuously.These facilities are to make up by the form of the skewed slot that has reception funnel and ladle spout, are arranged on the salient pole inductance of excitation RMF in the melt around it.

It is relative 10% that the maximum desulfurization degree that utilizes soda ash to obtain during as desulfurizing agent with the magnesium powder in this facility is about per second, and be about 50% after removing sulphur.When this facility reaches when per hour being about 120 tons productivity ratio, power consumption is about 2 kilowatt hours per ton.

Although this facility reaches good relatively technical result, its absolute desulfurization depth is low relatively.And because it is very high to apply enough thick lining heat loss in this facility.

In another association area, in typical channel induction furnace, the melt that is positioned on the shaft mainly stirs under thermal convection current consumes, because the melt of comparing in the groove with the melt of shaft is always overheated.In addition, on the top of shaft, shaft and relevant with the inhomogeneities of induced current density field certain barometric gradient appears pointing to.The melt stirring intensity is low in shaft, and this increase makes melt temperature even required time of composition evenly and in the stove, and hinders by improving the shaft height and increase the capacity of stove.Wish improving the melt stirring intensity handles the required time of melt reducing.

Summary of the invention

Thereby an object of the present invention is a kind of utilize one or more spirals by m phase amplitude, frequency and phase modulated current system (perhaps by the electric current under the various combinations of above-mentioned adjustment type) excitation advance magnetic field control class iron or non-ferrous metal continuously, the fixing method of the crystal structure of ingot or ingot casting.As following assessment is showed, under certain group modulation parameter is selected, the not fixed component of electromagnetic body force (" EMBF ") field (promptly, time correlation) be much higher than its fixed component (being that the time is irrelevant), because the liquid core that this can more effectively stir ingot and ingot casting is compared in the increase of turbulence intensity with conventional method.In addition, under certain modulation parameter combination, EMBF can change in time by the recurrent pulse mode, and this guarantees the fine and closely woven equiaxed crystal structure of ingot and ingot casting.The spiral that application the has three or more controllable parameters magnetic field energy of advancing is controlled spiral subtly and is advanced magnetic field to the stress effect of crystal melt, thereby provides optimum foundry engieering to every kind of situation.

Electrodynamics assessment shows, uses according to frequency of the present invention and amplitude-modulated RMF, and does not modulate the peak value that RMF compares its electronics muscle power and is higher than for setting up the ratio increase of the used additional-energy of this modulation MHD by out-of-proportion.The raising of this EMBF peak value is that these harmonic excitations strengthen the small-sized eddy current of heat and material Transfer because the not fixed component of foundation EMBF of the present invention field comprises high-frequency harmonic.Thereby, as test shows, use the density and hardness that improves ingot casting by the magnetic field of this method modulation.The process controllable parameter, the degree of depth and frequency, warbled skew and frequency, the power of for example vibrating the width of cloth modulation influences duration etc., the quantity increase further provide more flexibly and control for crystallization process and production have the ingot of crystal structure of the specification requirement under the various particular cases and ingot casting.

The present invention also proposes liquid metal in the outer alloying class ferrous metal melt-flow of a kind of stove to purify method and a kind of equipment of realizing this method of objectionable impurities, it can improve the intensity that melt stirs significantly under the low-power inductor in the size small device, and increase lining thickness simultaneously and reduce heat loss.

In order to realize these advantages, the inductor winding in this equipment is applied the modulated magnetic field that frequency and amplitude-modulated electric current move with the excitation spiral, this and then melt excitation mirroring modulated current to flowing in the groove.The reciprocation in these electric currents and magnetic field produces electromagnetic body force, the fixed component of these electromagnetic body forces in each cycle surpasses the fixed component of the EMBF of unmodulated magnetic field excitation, and the not fixed component of electromagnetic body force excitation compact scroll structure, this improves turbulence intensity.Thereby, obviously improve melt and alloy addition or and be used for removing the stirring intensity of the reagent of objectionable impurities.

In order to realize this method, can realize the main change in this equipment design by the design that changes inductor.Can become to work on the temperature of 800-900 ℃ of scope these inductor design.Thisly for example allow inductor to be installed in the lining of this facility in the ability of working under such temperature.For this reason, method of the present invention constitutes the magnetic circuit of inductor from the iron pottery (for example, fire clay, magnesite, colored magnesite or high temperature concrete) of the so-called representative refractory material that has the filler of representing iron powder or cobalt powder.The size of powder for example can be 1mm, and the content of powder in this refractory material can be depending on employed refractory type of material.After fully stirring, depend on that with shape the form of each primitive of the design of specific stove produces this material, and this material of then annealing.Under the Curie temperature of this filler, this material keep it magnetic, non-conductive, the coefficient of overall heat transmission is enough low, thereby can be used as the magnetic circuit of inductor and the lining of this equipment simultaneously.

This design of RMF inductor can be arranged to the RMF source the biglyyest near melt and the required function of reduction inductor.Because inductor coil ground is positioned at the high-temperature region, their design also is different from the conventional inductor coil of using in the metallurgical technology greatly.

The method of the technical process of the reinforcement channel induction furnace that the present invention proposes and the change that design is introduced to stove are made significant contribution to the improvement of technical equipment.

Another object of the present invention provides a kind of stirring method of strengthening the melt in the stove, and wherein the electric current in the elementary winding of m phase furnace transformer is by the ground of the cycle synchronisation in the time function or common phase ground frequency and Modulation and Amplitude Modulation.As following assessment illustrated, under certain of modulation parameter group was selected, the MHD stress effect on the melt was increased to the bigger degree of energy that consumes than modulation, and this makes the melt temperature homogenising in the groove of induction type tank furnace.In addition, the melt that comprises in the shaft is subjected to the influence by (rotation) magnetic field of advancing of method of the present invention modulation, and this makes melt temperature and chemical composition homogenising in the shaft of induction furnace and electric arc furnaces.Also propose to have and be based upon in the lining and the induction furnace of inductor that be used for realizing described MHD effect and the design of electric arc furnaces.

An object of the present invention is to provide a kind of utilization by on the time periodically harmoniously or the spiral of the non-m phase spiral current system excitation that changes harmoniously advance (especially, rotate and axially advance) magnetic field force influence the method for conducting medium, wherein electric current common phase ground or synchronously amplification and by the periodic function of time hierarchically frequency and Modulation and Amplitude Modulation.

A further object of the present invention is under certain selection to electric current, to compare the unstable component of tens times of ground raisings modulated amplitude, frequency and BMEF with unstable EMBF component with the stable of non-modulation magnetic field excitation.The ripple bag of EMBF comprises more frequency component, thereby the electromagnetic response of medium can be a high non-linearity.The influence of this field of force on liquid medium cause medium temperature and concentration fast with dark homogenising.This method is more useful and can utilize the standard electric system that is used for encouraging this to realize than conventional method on efficiency.

Description of drawings

Fig. 1 and 2 illustrates super wavy ripple phenomenon.

Fig. 3 illustrates the amplitude dependence of dimensionless frequency and Modulation and Amplitude Modulation EMBF on the nondimensional time, and (following numerical value only illustrates the curve example embodiment of describing among this figure; ω ₁=1; ω ₂=7; ε ₁=0.1; ε ₂=0.6; R=0.5; P=1; γ=0): curve 1 respective frequencies and Modulation and Amplitude Modulation RMF; And curve 2 correspondences are not modulated RMF.

Fig. 4 illustrates the amplitude dependence that does not have the following no magnitude time of modulation to go up dimensionless EMBF, and (following numerical value only illustrates the curve example embodiment of describing among this figure: r=0.5; P=1): curve 1 respective frequencies and Modulation and Amplitude Modulation RFM; And curve 2 correspondences are not modulated BMF.

Fig. 4 A is the sectional side view according to stove of the present invention.

Fig. 5 is the vertical longitudinal profile of first type that is used for the magnetohydrodynamics facility of the continuous refining of class ferrous metal or alloying.

Fig. 6 is the vertical transverse section of first type of the MHD facility of the continuous refining that is used for the class ferrous metal got of the line 6-6 along Fig. 5 or alloying.

Fig. 7 is the vertical longitudinal profile of second type that is used for the MHD facility of the continuous refining of class ferrous metal or alloying, and wherein the back side of magnetic circuit can be made with the lamination electrical sheet.

Fig. 8 is the vertical transverse section of second type of the MHD facility of the continuous refining that is used for the class ferrous metal got of the line 8-8 along Fig. 7 or alloying.

Fig. 9 is first pattern that the inductor coil of the facility of Fig. 5 and 6 designs, and it illustrates under 1/4th isometric projections that cut.

Figure 10 is second pattern of the inductor coil design of the facility shown in Fig. 7 and 8, and it illustrates under 1/4th isometric projections that cut.

Figure 11 is the vertical section that has single-phase single groove induction furnace of the first embodiment inductor that encourages RMF.

Figure 12 is the horizontal profile of single-phase single groove induction furnace of the first embodiment inductor of the excitation RMF that has Figure 11 that gets of the line 12-12 from Figure 11.

Figure 13 is the vertical section that has single-phase single groove induction furnace of the second embodiment inductor that encourages RMF.

Figure 14 is the horizontal profile of single-phase single groove induction furnace of the second embodiment inductor of the excitation RMF that has Figure 13 that gets of the line 14-14 from Figure 13.

Figure 15 is the vertical section of single-phase single groove induction furnace of Figure 11, and there is the shaft of prolongation in this furnace zone and has and is used for encouraging the spiral three-phase inductor in magnetic field of advancing.

Figure 16 is the vertical section of high power capacity melt chamber that has the electric arc furnaces of RMF inductor.

Figure 17 is the horizontal profile of high power capacity melt chamber of the electric arc furnaces of the RMF inductor that has Figure 16 got of the line 17-17 from Figure 16.

Figure 18 schematically illustrates the advance m phase spiral current system in magnetic field of excitation spiral.

Figure 19 schematically illustrates the m phase axial current system of excitation RMF.

Figure 20 schematically illustrates the m phase ring current system that excitation moves axially magnetic field.

Figure 21 illustrates the amplitude dependence of dimensionless EMBF on the nondimensional time: curve 1 respective frequencies and amplitude-modulated RMF; Fig. 2 correspondence is not modulated RMF.

Figure 22 illustrates when not having super ripple under the different mean flow raties turbulent flow regular wave energy density to the dependence of frequency.

Figure 23 illustrates under the flow velocity that has super ripple turbulence energy density to the dependence of frequency.

Figure 24 illustrates the dependence of the ratio of average turbulent flow flow velocity and magnetic field angular speed to the Common Criteria of foundation MHD procedure parameter foundation.

Figure 25 illustrates the dependence that the melting rate related with surpassing ripple increases refining quality: there is super ripple in 1-; There is not super ripple in 2-.

Figure 26 illustrates ingot density to the dependence from the distance of ingot center line: there is super ripple in 1-; There is not super ripple in 2-.

The specific embodiment

Foreword

This paper comprises a kind of method of accelerating technical finesse and improving production quality in metallurgy industry, foundry industry and chemical industry.This method is based on handling especially based on strengthening stirring by applying the shifting magnetic field reinforcement technique of following super wave-wave type, the super wave mode activity that this wave mode is described in the new theory of " TheGreat Law of the Universe " literary composition according to Irving I.Darkik, this article be distributed on " Cycles " magazine in March, 1994/phase in April (V.44, No.5) in.At " Cycles " magazine V.45 other consult Irving I.Dardik, No.3, the 1995 one interim articles of delivering " The Law of Waves " and he is at website www.dardikinstitute.org, " the Superwaves:The Realitythat is Existence " that delivers on 2002.These articles integral body are separately included conduct with reference to data.

As pointing out in the article of Dardik, generally accept all things of occurring in nature on the science by atomic building, atom moves about in perpetual motion, and they attract each other and in case repel each other when being extruded in another when atomic distance is very little.Completely contradict, the hypothesis of Dardik is that all things in the universe are made of ripple, and the activity of ripple is called " super fluctuation ".Super fluctuation cause and be the motion in material (that is, two changes define material-space-time simultaneously).

The change of wave frequency and amplitude not independently and differ from one another and each other concomitantly, is not represented two different levels simultaneously thereby in essence.Ripple frequency any increases to all ripples that wherein contain less ripple and contain the frequency that changes and sets up new wave mode, and can not exist under another person's the situation not having.

Each ripple must contain less ripple and be included in the bigger ripple.Each high amplitude low frequency master ripple is by the higher short arc small echo modulation of many frequencies like this.Super fluctuation is the process that ripple is just fluctuating in another ripple, and best and another ripple is shared the quantile relation.

The super fluctuation of Fig. 1 (from the article of Dardik, adapting) illustrative ripple phenomenon.Fig. 1 describes low frequency master ripple 11 for example by small echo 12 and 13 modulation. Small echo 12 and 13 incrementally has higher frequency (comparing with main ripple 11).Other frequency even higher small echo can be modulated main ripple, but do not illustrate for the sake of simplicity.Identical super fluctuation ripple phenomenon is described under time domain among Fig. 2.

The moving new principle of this wave-wave shows that ripple frequency and intensity of wave (amplitude square) are simultaneous and continuous.Two kinds of dissimilar energy (that is, ripple carry with proportional energy of its frequency and and the proportional energy of its intensity) thus also be that simultaneous and continuous energy is ripple or " ripple/energy " that fluctuates.

Can utilize the experience conclusion of setting up in electrodynamics and hydromechanics equation and some the test magnetohydrodynamics to study this phenomenon.Thus, expect that the result of study to super ripple can generally promote our understanding to super ripple phenomenon in metallurgical industry, foundry industry and the chemical industry.

Metallurgical industry, foundry industry and chemical industry are among the maximum industrial branches of energy consumption in developed country.Thereby for example, the power consumption of producing steel alloy in the electric arc furnaces is about 400-500 kilowatt-hour/ton (this numeral is only relevant with the production process of steel, does not comprise the electric energy that consumes in Cast Iron Production and the steel rolling).The electric energy of producing one ton of copper alloy consumption of production in one ton of magnesium alloy and the channel induction furnace in the resistance furnace is also near about 400 kilowatt-hours.

In order to produce high-quality steel, it is very important thoroughly stirring molten metal between casting cycle.As back explanation like that, introduce mixing power and strengthened stirring and also obviously reduced power consumption simultaneously by having amplitude and warbled non-linear super ripple, thereby obviously increase economic efficiency.

Following simple computation can provide total notion of potential saving.Price at U.S.'s electric energy is quite complicated.Different state electricity price differences.It also depends on the peak value that energy consumes very much, on average goes up electricity price and is about at least 15 cents/kilowatt-hours.Like this, above-mentioned 400-500 kilowatt-hour/ton cost is the 60-75 dollar of metal per ton.The totle drilling cost of producing steel plate and shaped steel is about 300 dollars/ton.The cost of electric energy (i.e. the expense share that can obviously reduce by the super ripple that is used for stirring) of producing steel consumption during this must come out of the stove is in the scope of about 20-25% of metallurgical production totle drilling cost.

The productivity ratio of producing, handle the Metallurgical Factory of melt or electrolytic solution and chemical plant be by fusion process speed or add melt to or solution in the course of dissolution speed of reagent and the decision of the chemical reaction rate in melt or the electrolytic solution.Other condition equates that the speed of said process depends on the intensity that stirs melt (or solution) in the technical equipment down.This factor also determine the structure of melt in the crystallization process and continuously, the production of stable metal ingot and ingot casting, thereby and determine their engineering properties.The intensity that stirs melt and solution is productivity ratio, production metallic article and the energy consumption of various chemical materials and the principal element of their quality of decision metallurgy and chemical industry equipment.

Thereby, in metallurgy industry, foundry industry and chemical industry, notice that stirring intensity looks like quite natural.Estimation to the average speed of the turbulent flow of rotating MHD stream shows, this speed is proportional to the square root of electromagnetic body force amplitude, and itself so that be proportional to slippage (that is, be proportional to difference ω/p-Ω: wherein ω/p be the RMF rotational angular, p is the number of pole-pairs amount, and Ω is the melt rotational angular).Like this, by following from E.Golbraikh, " Semiempirical Model of Turbulent Rotating MHDFlows " at the Proc.5 of A.kapusta and B.Mikhailovich ^ThInternal.PAMIR Conf., Ramatuelle, France, Septermber 16-20,2002, the structure among the I-227-I-230 (this article also integral body is included as a reference) is determined the mean angular velocity that the accurate solid core of turbulent flow is rotated:

Ω≈(Q/2)(√1+4/Q-1)ω， (2)

Q=Ha wherein ²δ z/Re _ωCo; Here $\mathrm{Ha}=\mathrm{BoRo}\sqrt{\mathrm{\σ}/\mathrm{\η}};$ δ z=Zo/Ro; Zo is a melt height; Ro is the radius that contains the appearance body of melt; Re _ω=ω Ro ²/ ν; ν is the kinetic viscosity of melt; σ is the conductance of melt; And Co=0.018 is an empirical.

Super ripple modulated magnetic field is to the assessment of the influence of steel production

The temperature and the fully even required time and the liquid rotational angular velocity of their turbulences mixing of melt or electrolytic solution are inversely proportional to.Like this, when rotating speed increased by 1.5 times approximately, homogenization time reduced by identical ratio.Owing to homogenization time accounts for 50% of total duration of pouring, this allows to reduce by about 20% fusing duration in electric furnace, and for outer desulfurization and the dephosphorization of handling in about 50% ground quickening MHD facility of stove.

Because of the power that stirs facility in MHD accounts for the 1-1.5% of furnace transformer power usually, the fusing duration reduce saves energy especially significantly.In the electric arc furnaces fusing 1.5 times of duration reduce specific energy consumption is dropped to 270-330 kilowatt-hour/ton (be that the specific energy consumption saving reaches 130-170 kilowatt-hour/ton approximately, thereby 20-26 dollar/ton).

In ingot (ingot casting) crystallization process, use the assessment of the effect of super ripple modulated magnetic field

Include as demonstration in the United States Patent (USP) 2,963,758 of the Pestel of the reference of this paper etc. as integral body and to reach the optimum crystalline texture of steel ingot under the following conditions like that:

ωB ²R ²≈5×10 ^-3-11.3×10 ^-3T ²m ²/s (3)

Wherein ω is the magnetic field rotational angular velocity, radian per second; B is magnetic strength T; And R is liquid pit (crater) radius, rice.Like this, the essential value of magnetic strength is:

B～0.04-0.06T. (4)

Continuous pouring facility (" CCF ") is gone up the inductor of installing and produce magnetic field in melt.Rotate (moving) magnetic field induction electric current, the reciprocation in electric current and described magnetic field causes the electromagnetic force that melt occurs influencing.Depend on CCF type and productivity ratio, the rated power of inductor is about 150-300 kilowatt (promptly about 10-12 kilowatt-hour/ton) under specific energy consumption.When adopting amplitude and frequency modulation(PFM) electric current, under similar inductor power, obviously accelerate the crystallization process of ingot, this improves the productivity ratio of CCF.In addition, also improve the strength characteristics of casting metal and reduce the porosity.

In addition, as preliminary test has illustrated, when adopting amplitude and frequency modulation(PFM) electric current, the power effect character of electromagnetic field on melt obviously changes, and this is because the flash that causes the melt vibration is facilitated in the increase (this strengthens AFR) of EMBF and EMBF average jointly.The compound action of these factors causes obviously improving the quality of continuous ingot.

The potential application of the technical super ripple modulated magnetic field of chemical industry

In chemical industry, for exchange and the acceleration chemical reaction that adds heat-flash and material stirs.For agitated liquid,, use turbine type and impeller-type stirrer as a kind of rule.In this case, finish the homogenizing of agitation phases concentration and temperature by circulation and DIFFUSION IN TURBULENCE.Utilization can be from Tatterson, G.B., Calabrese, R.V. and Penney, " the Industrial Mixing Technology:Chemical and BiologicalApplication " of W.R, the following formula that obtains among the AI Chem.Engng.Publ.1994 (its integral body is included as a reference) carry out the approximate calculation of total homogenization time τ under the turbulent flow mode to the equipment that has mechanical agitator:

τ≈5V/nd ³，(5)

Wherein V is an equipment volume, the unit cubic meter; N is the agitator revolution; And d is its diameter.

Dimensionless EMBF is to relative frequency (ω=μ here _oσ wR _o ²) dependence show, insignificant little for very little ω value EMBF.

The amplitude that forceful electric power is separated the ω of solution when applying the RMF of frequencies omega=314 radian per seconds in the container of 1 meter of diameter is about 0.001.0.4 relative EMBF value equals f=ω r/2～0.0002 under the rice radius.Thereby, do not observe rotation in the time of in electrolyte (for example sulfuric acid) being placed on the enough strong RMF that magnetic strength is about 0.07T, thereby in fact the RMF of low-frequency current excitation does not influence electrolytic solution.But, if rotating current density, perception ground guides in the electrolyte, the reciprocation of this and RMP can encourage enough strong EMBF field to rotate electrolyte under high angular speed.The modulation of BMF and current density field obviously improves the efficient of electromagnetic agitation parts, when Production Example can be used this modulation valuably to substitute the conventional mechanical agitator of using when concentrating the corrosive substance of bronsted lowry acids and bases bronsted lowry in chemical industry.

The physical mechanism of the power influence of the super ripple modulated magnetic field of frequency and amplitude

Present explanation has the axle of the container of induced liquid to rotate by fixed angles speed by strip winding and the power of the non-modulation RMF that permanent magnet encourages influences.The magnetic field B that not motion liquid is rotated by same angular velocity encourages the axial current that rotates at the same rate in this induced liquid.The reciprocation generation in induced-current and magnetic field and the EMBF of magnet rotational alignment.These power have fixed component and fixed component not, and the latter presses double frequency 2 ω and the amplitude cycle ground that equates with fixed component changes.Under the effect of these power, liquid begins to rotate by certain angular speed Ω＜ω, and wherein faradic density and slippage i.e. (ω-Ω) be directly proportional.

If the angular speed of magnet is not (that is, it is the cyclomorphosis in time) fixed, this additional movement induction extra current, the reciprocation of the latter and modulated magnetic field produces the additional force that acts on the liquid.As the consequence of this influence, the mean angular velocity that liquid rotates increases and two-dimension vibration occurs, and this is agitated liquid automatically.Certainly, if the magnet rotational angular velocity is unfixed, need a certain amount of additional merit to realize its rotation under identical main speed omega.

Method by following this proposition of realization.

To water the non-magnetic space that therein mould places m phase inductor to melt, and the winding of inductor is applied electric current by described method modulation.These electric currents produce frequency and the amplitude-modulated magnetic field that spiral moves (particularly, rotate and move axially) in melt, the m phase current system that induction is modulated by described method in melt is transferred in this magnetic field.

In the ordinary course of things, as the interactive result in described electric current and magnetic field, three-dimensional EMBF field occurs, each component of this m is made of a permanent component and one group of complexity pulsation and vibration that has various amplitude, frequency and initial phase.

The amplitude of the azimuthal component of the EMBF of dimensionless shown in Fig. 3 is to the dependence of nondimensional time, and wherein, 1-is by amplitude and frequency modulation(PFM) current excitation; There is not modulation in 2-.The radial component of the EMBF of dimensionless shown in Fig. 4 amplitude is to the dependence of nondimensional time, and wherein, 1-is by amplitude and frequency modulation(PFM) current excitation; There is not modulation in 2-.

Under the effect of this EMBF field, in melt and naturally near the crystallization forward position, keep space structure complicated and have a turbulent flow of forced oscillation that its frequency depends on the frequency spectrum of EMBF field.Should flow the fully generation of suppressed column crystal according to the present invention, thus the ingot (ingot casting) that solidifies in this state preferably have wait spool, the particulate close packed structure.

In continuous casting equipment, m phase inductor can be placed on the below (seeing Fig. 4 A) (under the steel cast situation) of crystallizer or be structured in the crystallizer.In a preferred embodiment of the invention, casting mold is used the material of magnetic field shielding in minimum zone is made.

Proposal facility shown in Fig. 5 and 6 comprises lining groove 21, the ladle spout 23 that has reception funnel 22, the injection bucket 24 that is used for reagent and support 25.In the lining of groove, be provided with the magnetic circuit 27 made with the iron pottery and the inductor of coil 28 (referring to for example Fig. 9 and 10), coil 28 is a form with the ceramic box that has helical pipe 29, filling out liquid metal in the pipeline 29, the fusion temperature of this metal well below the fusion temperature of melt to be processed but its boiling temperature is much higher than the boiling temperature (for example tin can serve as this metal) of melt to be processed.One is used for electric current being provided to coil and being used for metal is poured into pipeline 29 for another solid electrode 30 of tubulose.

Fig. 7 and 8 illustrates second kind of design form of this facility, and it comprises lining groove 21 ', wherein be arranged in the lining of stove with the utmost point 26 ' that the iron pottery is made, and the pedestal 27 ' of magnetic circuit is made and is fixed in the cannelure on the boiler clothing 23 ' with the lamination electric steel plate.Magnetic pole 26 ' by earthenware 31 ' protection magnetic circuit is avoided melt, and the thickness of pipe 31 ' is preferably selected to the Curie temperature that the hull-skin temperature that makes this pipe is no more than the iron pottery.

The facility of this proposal is by following operation.Can be provided to funnel to liquid metal from casting ladle blast furnace or furnace cupola.Provide necessary reagent continuously from injecting bucket 24.Melt-flow is crossed groove 21, and melt is subjected to the influence according to EMBF of the present invention in groove, and this makes melt and reagent mix consumingly.The melt of handling is discharged in the casting ladle continuously.Providing under the melt with some reagent (soda, lime or magnesium powder), these reagent also melt and form the slag that objectionable impurities in enrichment, remove slag from melt before discharging metal from casting ladle.

Like this, providing a kind of moves (promptly at the spiral by m phase amplitude and the excitation of frequency modulation(PFM) current system, thereby moving under the screw movement rotated melt and move axially along the longitudinal axis of groove 21 simultaneously) the outer alloying continuously of stove or to the method for objectionable impurities purifying class ferrous metal melt, wherein depth of amplitude modulation and frequency modulation(PFM) skew is along a variation of long bushing pipe under the effect in magnetic field.Assessment illustrates, the peak value of electromagnetic body force is higher than peak value when not having modulation in the case, and this guarantees the time that strong melt stirring, shortening temperature and the total homogenising of composition are required and obviously accelerates the dissolving of alloy addition and the speed that objectionable impurities is discharged to the chemical reaction in the slag.A kind of design that realizes the facility of the described method that is used for high-temperature fusant also is provided.

Another method of proposing according to the present invention relates to the reinforcement of fusing and melt whipping process.This method of the present invention can obviously improve melt stirring intensity, shortening fusing time in shaft and because the reaction of the boundary of reinforcement metal and slag can improve the quality of metal and alloy.In addition, this method can strengthen the capacity of slot type reacting furnace at the power that furnace transformer is not provided by the increase of shaft height.

Although RMF excitation needs additional energy consumption, the obvious shortening of fusing time (for example 20%) can obviously reduce the energy consumption of producing metal and alloy in the channel induction furnace.As a rule, current electric arc furnaces is equipped with the electric arc stator that a tame swedish company ASEA makes, and they are installed in the below of furnace bottom.Capacity according to stove is fed to the conspicuous electric current of the about 0.35-1.50 of frequency on the stator winding.Stator power account for usually furnace transformer power 2% and can reach 0.5MVA for the large volume stove.

The present invention proposes strengthens fusing and melt stirring method and can reduce melt and stir required power consumption and obviously strengthen fusion process in the electric arc furnaces of the RMF inductor that has novel designs, this so that cause shortening, the stove output of fusing time increase, power consumption minimizing and reduce the metal consume.

The design of this RMF inductor is obviously different with the known design that employing is gone up in metallurgical and casting.For this reason, a kind of method of the present invention constitutes the magnetic circuit of inductor with the iron pottery (for example, fire clay, magnesite, colored magnesite or high temperature concrete) of the representative refractory material that has iron powder or cobalt powder filler.The size of powder for example can be 1mm, and the content of powder in this refractory material can be depending on employed refractory type of material.After fully stirring, depend on that with shape the form of each primitive of the design of specific stove produces this material, and this material of then annealing.Under the Curie temperature of this filler, this material keeps its magnetic, non-conductive and the coefficient of overall heat transmission is enough low, thereby can serve as the lining of magnetic circuit inductor and this facility simultaneously.This design of RMF inductor can be arranged to the RMF source the biglyyest near melt and the required power of reduction inductor.In addition, thus this design obviously reduces the size of the non-magnetic gap between liquid metal and the inductor gets rid of the field weakening that boiler clothing causes.Because inductor coil also is positioned at the high-temperature region, their design also is different from the conventional inductor coil of using in the metallurgical technology greatly.

The method of the technical process of the reinforcement channel induction furnace that the present invention proposes and the change of introducing in the stove design are made significant contribution to the improvement of technical equipment.

As an example, accompanying drawing illustrates the structural change that has proposal so that single-phase single groove induction furnace of above-mentioned advantage of the present invention is provided.

Figure 11 and 12 illustrates vertical section and the horizontal profile of first embodiment of stove of the present invention.This stove comprises lining body 41.The elementary winding 44 of groove section 42, furnace transformer 43, this transformer, groove 45 and support 46.The magnetic circuit made from the iron ceramic member 47 is based upon in the lining of shaft 41.The coil made from the form of the ceramic box that has helical pipe (for example Fig. 9 and 10 pipeline 29) 48 is connected on the magnetic pole of shaft 41.Pipeline 29 is being filled liquid metal, and the fusion temperature of this metal is significantly less than the temperature of the melt in the stove and the boiling temperature (for example tin can serve as this metal) that its boiling temperature is much higher than melt.

Introduce 30, one electrodes of solid state electrode among Fig. 9 in the bottom of the low relatively coil 48 of temperature and be tubulose and another electrode is solid, apply electric current by these electrode pair liquid metal windings, and metal be poured in the groove 29.By lining 51 magnetic pole of magnetic circuit 47 and melt are separated, its thickness is chosen to make the temperature on layer 51 outer surface to be lower than the Curie temperature of iron pottery.

Figure 13 and 14 illustrates the stove of the second embodiment of the present invention, and wherein magnetic pole 47c and the coil made from the iron pottery 48 ' all is arranged in the furnace lining, and the bottom 47b of the magnetic circuit of RMF inductor be make with the laminated transformer steel and be fixed on the boiler clothing.

Figure 15 represents that there is the shaft and the three-phase inductor of prolongation in the furnace zone of the first embodiment of the present invention shown in Figure 11 and 12.Be arranged on the change of the phase place of the coil in vertical and the level, the magnetic field that this inductor can encourage helical magnetic field RMF or move along the stove axle according to these.Under such field amplitude and frequency modulation(PFM) situation, spiral, rotation or vertical current average speed separately and all obviously increases (preferably at least one magnitude) of fluctuation velocity component that keep the high-strength spectrum of turbulence of pressure of melt.Thereby, can shorten fusing time in the enough big stove of volume (for example 20%).

Under the current-modulation of the elementary winding of feed-in furnace transformer, the electric current in the groove also can be by frequency and Modulation and Amplitude Modulation.These electric currents and intrinsic magnetic field reciprocation cause occurring additional, unfixed rotation EMBF field, and it makes the miscarriage life turbulent flow in the groove and the heat exchange of the metal in reinforcement and the shaft.In addition, under the cost that increases to a certain degree of furnace transformer power, also increase the release of Joule heat in the groove.

Figure 16 and 17 illustrates high power capacity (for example 200 tons of capacity) melting chamber of a kind of electric arc furnaces of the present invention, and it comprises steel bushing 61a, column part lining 62a, bottom lining 63a and furnace roof 64a.In the lining 63a of bottom, embed the m that has bottom 65a and magnetic pole 66a that makes with the iron pottery that contains cobalt filler RMF inductor mutually.This ceramic Curie temperature for example is 1000 ℃.The design of coil 67a can be identical with the design of the coil 28 (Fig. 9) that is used for the tank furnace inductor described above.Because the iron pottery coefficient of overall heat transmission is low, and these coils can for example work on the temperature of 300-400 ℃ of scope, and the magnetic pole of this inductor can be the biglyyest near melt, thereby can obviously reduce power and the frequency of utilization and the Modulation and Amplitude Modulation electric current of inductor.

Also provide a kind of utilization by on the time harmoniously or the spiral of the m phase spiral of non-cyclomorphosis harmoniously (especially axially or other ground on orientation) current system excitation move (especially rotate with axially movable) magnetic field and force influence the method for conducting medium, wherein these electric currents are homophase or synchronous and amplify by the time cycle function and to reach hierarchically frequency and Modulation and Amplitude Modulation.Under certain of current-modulation amplitude and frequency is selected, with by do not modulate the fixing of magnetic field excitation and not fixedly the EMBF component compare, EMBF is the best tens times of ground increases of amplitude of fixed component not.This EMBF ripple bag comprises more frequency component, thereby and the electromagnetic response of this medium can be high non-linearity.The influence of this field of force on liquid medium causes the quick and deep homogenising of medium temperature and concentration.More effective and can utilize this standard electric system of excitation to realize on this method energy than known method.

Magnitude ground of the method for the pressure influence of this proposition improves stirring efficiency.And guarantee darker, the homogenising faster of melt thus.As an example, press the following electrokinetic process in the conducting circular cylinder under described amplitude and the frequency modulation(PFM) RMF effect of determining on the mathematics.

Circular cylindrical coordinate r,

Utilizing under the z system and describing these processes by ratio B=rotA with the related magnetic induction vector potential of induction is easily.In the case, the axial component of current density is:

And induction radially with azimuthal component is:

The azimuthal component of EMBF is defined as:

And radial component is defined as:

Re is the real part of complex variable.

Vector A z is described by following formula:

Wherein

It is medium velocity; μ ₀=4 π 10 ^-7Hn/m is the magnetic conductivity of vacuum; σ is the conductance of medium; And t is the time.

Under following boundary condition, find the solution formula (10):

Wherein NI is the linear current load; ω ₂(t)=ω ₂[1+ ∈ ₁Sin (ω ₁T+ γ)]; And p is the number of pole-pairs amount.

Utilize the characteristic value of vector potential, time, coordinate r and angle φ:

Problem (10), (11) become nondimensional, and in condition

Under obtain:

Wherein

It is relative frequency;

a _zIt is the z component of this dimensionless vector potential; τ is a nondimensional time; And following r is the dimensionless coordinate.

Can with dimensionless with reference to frequency=1 stack RMF and modulation RMF:

a _z＝a _z1+ε ₂a _z2· (13)

Form under the separating of approximation problem (12).

In (13) substitution (12), obtain:

Problem (14), (15) have explicit solution:

Wherein

It is the Bessel function of the single order type in the complex domain.

Usually a _Z1Write as following form:

a _z1＝(a ₁₁+ia ₁₂)(cos2πφ ₁+isin2πφ ₁)，(18)

Wherein,

a _Ik=a _Ik(r)

Problem (14), (16) have half analytic solutions, and can be a _Z2Write as:

a _z2＝(a ₂₁+ia ₂₂)(cos2πφ ₂+isin2πφ ₂)，(19)

Wherein

$a_{21}=\mathrm{Re}[\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{\mathrm{\α}}_{2n}\left(\mathrm{\τ}\right)J_{2p}\left({\mathrm{\β}}_{n}r\right)-\mathrm{\θ}\frac{r^{2p}}{2p}],$

$a_{22}=\mathrm{Im}[\underset{n=1}{\overset{\∞}{\mathrm{\Σ}}}{\mathrm{\α}}_{2n}\left(\mathrm{\τ}\right)J_{2p}\left({\mathrm{\β}}_{n}r\right)-\mathrm{\θ}\frac{r^{2p}}{2p}],$

${\mathrm{\α}}_{2n}\left(\mathrm{\τ}\right)={\mathrm{\χ}}_{2n}+C_n^{*}{e}^{-r},$

$C_n^{*}=\frac{1}{p}\frac{{\mathrm{\β}}_n{J}_{2n+1}\left({\mathrm{\β}}_n\right)}{({\mathrm{\β}}_n^2-{4p}^2)J_{2p}^2\left({\mathrm{\β}}_n\right)},$

${\mathrm{\&chi;}}_{2n}=\underset{i=-\&infin;}{\overset{\&infin;}{\mathrm{\&Sigma;}}}{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">k</figure-callout>}}_{2\mathrm{<figure-callout\; id="2"\; label="ni\; e"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">ni</figure-callout>}}{e}^{}{}^{2\mathrm{\&pi;di\&tau;}},$

Im is the imaginary part of complex function,

Obviously,

${\mathrm{Reb}}_r=\frac{P}{r}\{a_{11}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1+a_{12}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1+2{\mathrm{\&epsiv;}}_2(a_{21}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2+a_{22}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2)\},---\left(21\right)$

Wherein

${\stackrel{\&CenterDot;}{a}}_{\mathrm{ik}}=\frac{{\&PartialD;a}_{\mathrm{ik}}}{\&PartialD;\mathrm{\&tau;}};{{\stackrel{\&CenterDot;}{a}}^{\&prime;}}_{\mathrm{ik}}=\frac{{\&PartialD;a}_{\mathrm{ik}}}{\&PartialD;r}$

The azimuthal component of EMBF is:

$+{\mathrm{\&epsiv;}}_2^2[f_1{a}_{21}+f_2{a}_{22}+(a_{21}{\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">f</figure-callout>}}_2+a_{22}{f}_1)\mathrm{<figure-callout\; id="4"\; label="sin"\; filenames="C20038010927900391.png,C20038010927900431.png"\; state="\{\{state\}\}">sin</figure-callout>}4\mathrm{\&pi;}{\mathrm{\&phi;}}_1+(a_{22}{f}_2-a_{21}{f}_1)\mathrm{<figure-callout\; id="4"\; label="cos"\; filenames="C20038010927900391.png,C20038010927900431.png"\; state="\{\{state\}\}">cos</figure-callout>}4\mathrm{\&pi;}{\mathrm{\&phi;}}_2]+---\left(23\right)$

$+{\mathrm{\&epsiv;}}_2[a_{11}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1+a_{12}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1][({\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="C20038010927900271.png"\; state="\{\{state\}\}">f</figure-callout>}}_1+{2a}_{21})\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2+({\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">f</figure-callout>}}_2+{2a}_{22})\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2]\},$

Wherein

The radial component of EMBF is:

${\mathrm{\&epsiv;}}_2^2[(f_2{a^{\&prime;}}_{21}-f_1{a^{\&prime;}}_{22})+(f_1{a^{\&prime;}}_{21}-f_2{a^{\&prime;}}_{22})\mathrm{<figure-callout\; id="4"\; label="sin"\; filenames="C20038010927900391.png,C20038010927900431.png"\; state="\{\{state\}\}">sin</figure-callout>}4\mathrm{\&pi;}{\mathrm{\&phi;}}_2+(f_2{a^{\&prime;}}_{21}+f_2{a^{\&prime;}}_{22})\mathrm{<figure-callout\; id="4"\; label="v\; cos"\; filenames="C20038010927900391.png,C20038010927900431.png"\; state="\{\{state\}\}">v</figure-callout>}\cos 4\mathrm{\&pi;}{\mathrm{\&phi;}}_2]+$

${\mathrm{\&epsiv;}}_2[a_{11}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1+a_{12}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1]\&CenterDot;[{a^{\&prime;}}_{21}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2-{a^{\&prime;}}_{22}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2]+$

$\left[({\mathrm{<figure-callout\; id="2"\; label="f"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">f</figure-callout>}}_2\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2+{\mathrm{<figure-callout\; id="1"\; label="f"\; filenames="C20038010927900271.png"\; state="\{\{state\}\}">f</figure-callout>}}_1\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_2)({a^{\&prime;}}_{11}\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">cos</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1-{a^{\&prime;}}_{12}\mathrm{<figure-callout\; id="2"\; label="sin"\; filenames="C20038010927900271.png,C20038010927900272.png"\; state="\{\{state\}\}">sin</figure-callout>}2\mathrm{\&pi;}{\mathrm{\&phi;}}_1)\right]\}.---\left(24\right)$

The pressure influence of benchmark BMF is not modulated in preceding four descriptions in formula (21) and (22).Be proportional to ε ₂ ²Item the pressure influence of BMF modulating part is described, and be proportional to ε ₂Item describe because EMBF vibration and the ripple that the modulation of RMF and the reciprocation between the non-modulating part produce.Obviously, amplitude and frequency modulation(PFM) to the increase of the size of EMBF fixed component greater than a magnitude, this increases the average velocity of rotation of medium and at the azimuth and add frequency four EMBF ripples and two vibrations different with initial phase in the radial direction, this additionally strengthens medium and stirs.

Above analysis consider near electric current and the field decay phenomenon lateral surfaces of conducting circular cylinder (liquid or solid-state) fully, promptly so-called Kelvin effect is in the size of the EMBF of amplitude and the generation of frequency modulation(PFM) electric current and the influence on the spatial distribution.This makes might select best electromagnetic parameter ratio to specific section, size and medium conductance.

This proposition method to the assessment of efficient calculating method by the angular speed of the plan solid core of the rotation turbulent flow of RMF excitation, this can be with following simple formula description:

$\mathrm{\&Omega;}=\frac{Q}{2}(\sqrt{1+\frac{4}{Q}}-1),$

Q=Ha wherein _a ²δ _z/ Re _ωC _oHa _a=B _aR _o√ σ/η is the virtual value of Ha Tuoman number; Re _ω=ω R _o ²/ ν is imitated by the Reynolds of the decision of the RMF rotating speed on the chamber wall that comprises melt; δ _z=Z _o/ R _oCo is an empirical (for not modulating RMFCo=0.0164, it is than modulation RMF height) of considering the RMF mudulation effect; Ba is the mean effective value of magnetic strength in the container; Ro is the internal diameter of chamber wall; η is the dynamic viscosity of melt; ν is the kinematic viscosity of melt; And Zo is the height of liquid phase post.

Rotate the kinetic energy E of stream _Kin=J Ω ²/ 2; Wherein J is the rotary inertia of rotating liquid; And hydraulic efficiency is to press power and driving and keep the ratio of the electric energy that rotational motion consumed to determine:

η _hydr≈E _kin/E _el

Obviously consumption and electric energy are higher than not modulating under the RMF situation under the modulation BMF situation.

M modulates screw thread mutually and revolves current system and produce in conducting medium along magnetic field that helix moves and (that is, rotate and move axially simultaneously), the minute surface current system that this and then induction are moved in the same direction.The electric current of induction and the reciprocation in magnetic field produce and act on the moving direction of magnetic field and the EMBF on the vertical direction, and wherein magnetic field comprises fixed component and fixed component not.

Under the effect of fixing EMBF component, produce the spiral flow (especially, rotate and move axially) of conducting liquid usually, it has turbulence structure as a kind of rule.Under the effect of fixed component not, the ripple and the vibration of excitation different frequency and direction in medium, this makes the flow structure turbulization down more.The energy of this turbulent flow part is not from the merit that effect realizes on stream of bed knife not and from the average flow energy.Thereby, obviously improving the stirring degree of depth of liquid, this causes the quick homogenising of temperature and impurity concentration.

When employing utilize km electrode (wherein m be the number of phases and k is the number of electrodes of every phase) additional frequency of excitation and during the Modulation and Amplitude Modulation current density field, because the reciprocation in this current density field and magnetic field, additional EMBF field component appears, this causes further strengthening this pressure influence and expands medium (for example, electrolyte, salt and the slag melt etc.) range of application of described method to having ionic conductivity.

Figure 18-20 represents the spiral of excitation by method improvement of the present invention respectively, rotate and move axially the space configuration of the simplest current system in magnetic field.

Figure 21 illustrates modulation and each self-energizing dimensionless EMBF of RMF that do not modulate dependence to the time.Clearly, under the parameter value of pointing out, by the honeybee value of the EMBF of modulation RMF excitation approximately than modulation case is not high 10 times.

The Duan Jie of back reaffirms super ripple and metallurgical and the related basic theory of related science disclosed herein.

Super wave excitation MHD technology is to make the carrier wave of uniqueness modulation serve as the rotary magnetic field of exciting current with the turbulent flow in the generation increase agitated liquid, thereby improves the character of melting rate and composite rate and improvement casting metal.

Such as noted, can be understood as the carrier wave that has amplitude, frequency and/or phase place modulation to super ripple.The vibration modulation is to change parameter of oscillation in time according to periodic law.Modulation first-harmonic (or vibration) can be described as carrier wave and its frequency can be described as carrier frequency.

On the mathematics, it is very important demonstrating for the super ripple of mixing of liquid stream.In the time of on being applied to metallurgical process, the enough little fluctuating of turbulence intensity is very important for the heat and the chemical homogenising of melt.

In fact the rotation of liquid metal in rotary magnetic field always is turbulent flow to a certain extent.Even the weak rotation of liquid melts still improves their characteristic, rise and fall because can find some vortex.But simple rotation (stream core angular speed is fixed) produces classical Kolmogorov turbulent flow (for example referring to Figure 22) under first approximation.In the case, turbulent flow can depend on rapid vortex size, is E=ε ^2/3r ^2/3, perhaps frequency domain is E (ω)～ω down ^-5/3, wherein ε is the flux of energy of unit mass on frequency spectrum, ω is a frequency and E (ω) is a spectrum energy density.

Under the simple rotation situation,

E(ω)～E ₀(ω ₀)(ω ₀/ω) ^5/3， (28)

E wherein ₀(ω ₀) be the energy that is injected in the system, it is corresponding to feature scale value L ₀Thereby in the case, in order to obtain being used for the eddy current of heat and chemical homogenising, we must press scale value L in system ₀Introduce energy, and at this energy after cascade on the frequency spectrum, we can obtain the vorticity on the following frequencies omega:

E(ω)～E ₀(ω)(ω ₀/ω) ^5/3。If Δ ω=ω/ω ₀Enough big, then Dui Ying vorticity is little.

If except average rotation, in system, occur greater than ω ₀Frequencies omega under outside fluctuation, we can be desirably in, and eddy current quantity increases on this frequency.This situation is similar to and the Karman vortex street occurs when the peak value that occurs some frequencies in the frequency spectrum is many times in main eddy current.We can be by the eddy current that occurs under the following estimation assigned frequency ω.Make E ₀～α ₁(F ₀/ ω ₀) ²Be to be ω to frequency ₀Eddy current the turbulence energy that rises and falls and to provide by current-sharing down is not provided.If because rising and falling appears in the external force under the frequencies omega, their energy composition is in the system:

E′(ω)～α ₂[F(ω)/ω] ². (29)

Like this, in frequencies omega, the relative eddy size is:

E′(ω)/E(ω)～(α ₂/α ₁)(F/F ₀) ²(ω ₀/ω) ^1/3(30)

Parameter alpha ₁And α ₂The response of the external power effect of characterized medium.If power F and F ₀Character is identical, then α ₁And α ₂Difference is little, thereby their ratio is near 1 (Figure 22).Can determine this size more accurately by test.

When utilizing super ripple modulated current, the calculating of the electromagnetic force of this frequency and Modulation and Amplitude Modulation current excitation shown in liquid, form the whirlpool power (for example seeing Figure 23) of adding.Except equal power F ₀Press ω ₀Outside～50 hertz of fluctuation amplitude, amplitude occurring is F～7/8F ₀, frequency is ω～2.3/2.5 ω ₀Pulsation rise and fall.

According to (30), we draw at this system medium frequency is that the turbulent flow of w rises and falls and should increase by following formula:

E′(ω)/E(ω)～(α ₂/α ₁)(7+8) ²(2.3+2.5) ^-1/3～(36+48)(α ₂/α ₁)(31)

Therefore, modulation external force should cause than the more intensive homogenising of influence of modulation forces not the influence of deposite metal.Thereby, for homogenising turbulence medium, can as among Figure 22, increase mean speed by improving inductor power (and Re), utilize super ripple than improving whirlpool power under the slow-speed of revolution as among Figure 23, perhaps adopt this two kinds of effects.

In the test, density metal that solidifies among the melt rate of the solid of super ripple raising adding in the liquid solution, the increase RMF and super ripple are by the such behavior of top number expected.

Figure 24 is the result of the original experimentation of the turbulent flow relevant with the super wave excitation of RMF.Contrast Q retouches out the ratio Ω/ω of uniform angular velocity to magnetic field angular speed, and wherein Q is that a representative is comprising Ha ²The parameter of the process set condition of (the expression electromagnetic force is to the ratio of viscous force).Q also with the agitating unit coil in current squaring proportional.When the electric current in the coil increased (Ha increasing), angular speed increased.Solid line is represented the General Theory relation between angular speed and the parameter Q.Data point above the solid line is used for not modulating RMF, and the point below the solid line is used for super ripple modulation RMF.

Master curve shown in Figure 24 makes can select essential speed state (required Reynolds number) under any combination of current amplitude and frequency.

Thereby work to be similar to the mean value that resistance reduces this speed on the turbulent flow low whipping speed of the increasing that super ripple causes.In the speed of seeing in the data of Figure 25 be not both with stir during the additional friction brought of the turbulent flow increase that causes of super ripple be consistent.Thereby super ripple has the potentiality that need not to improve under the undesirable and expensive higher mixing speed composite rate.

In the test aluminium alloy of fusing has been studied the influence of the RMF that modulates by super ripple.

The result of the test of melting rate shown in Figure 25.This result shows and can irrespectively improve melting rate with mixing speed.Obviously, under other condition same case, utilize about 22% ground of super ripple to improve melting rate.Thereby these fusion tests have been verified the ability of super ripple turbulization in essence and have been verified that the super ripple of metallurgical process utilization improves the validity of composite rate.

Solidified aluminum alloy 201 under similar stirring condition as fusion test.Difference is, the complete already solidified melt of energy under the effect of RMF.The inspection of solidifying ingot is shown the obvious Billy of the ingot that the RMF of super wave excitation produces is with not modulating the ingot more closely knit (seeing Figure 26) that RMF solidifies.This density improves the casting metal that is equal to every cubic centimetre and removes 5.7 hundred ten thousand microgaps.This prompting has formed on the mathematics turbulent flow immixture of super ripple prediction and this effect are processed metal is useful.

Claims (4)

1. a method of controlling the crystal structure of class ferrous metal and non-ferrous ingot and ingot casting wherein makes melt crystallization in the magnetic field of advancing by the spiral of m phase spiral alternating current system incentive, and described method comprises:

Provide and place metal bath inductor on every side;

To placing inductor around the melt to apply sequence with the m phase alternating current system of super wave-wave type modulation, the spiral of modulating with excitation in the melt magnetic field of advancing.

2. according to the method for the control crystal structure of claim 1, wherein said m phase alternating current system cycle ground is connected at interval by certain hour and is disconnected at interval by certain hour.

3. according to the method for the control crystal structure of claim 1 or 2, the amplitude of each vibration in the wherein said super wave-wave type and frequency be periodic variation in time.

4. according to the method for the control crystal structure of claim 1 or 2, the amplitude of each vibration in the wherein said super wave-wave type and frequency improve with the increase of crystalline solid phase thickness.

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