EP0803579A1 - Dispositif d'affinage sous vide de metal et dispositif associe - Google Patents

Dispositif d'affinage sous vide de metal et dispositif associe Download PDF

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Publication number
EP0803579A1
EP0803579A1 EP94909359A EP94909359A EP0803579A1 EP 0803579 A1 EP0803579 A1 EP 0803579A1 EP 94909359 A EP94909359 A EP 94909359A EP 94909359 A EP94909359 A EP 94909359A EP 0803579 A1 EP0803579 A1 EP 0803579A1
Authority
EP
European Patent Office
Prior art keywords
ejector
gas
nozzle
mixing channel
metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP94909359A
Other languages
German (de)
English (en)
Other versions
EP0803579A4 (fr
Inventor
Jury Sergeevich Komratov
Anatoly Alexandrovich Kirichkov
Viktor Pavlovich Novolodsky
Mikhail Andreevich Tretyakov
Gennady Viktorovich Burlaka
Viktor Andreevich Spirin
Alexandr Arkhipovich Fetisov
Vladimir Borisovich Alexandrov
Stanislav Ivanovich Zhigach
Anatoly Mikhailovich Sizov
Vladimir Evgenievich Nikolsky
Valery Vladimirovich Kabluka
Andrei Valerievich Savin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AKTSIONERNOE OBSCHESTVO "NIZHNETAGILSKY METALLURGICHESKY KOMBINAT"
Aktsionernoe Obschestvo Zakrytogo Tipa Kontsern" Struinye tekhnologii"
Original Assignee
AKTSIONERNOE OBSCHESTVO "NIZHNETAGILSKY METALLURGICHESKY KOMBINAT"
Aktsionernoe Obschestvo Zakrytogo Tipa Kontsern" Struinye tekhnologii"
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by AKTSIONERNOE OBSCHESTVO "NIZHNETAGILSKY METALLURGICHESKY KOMBINAT", Aktsionernoe Obschestvo Zakrytogo Tipa Kontsern" Struinye tekhnologii" filed Critical AKTSIONERNOE OBSCHESTVO "NIZHNETAGILSKY METALLURGICHESKY KOMBINAT"
Publication of EP0803579A1 publication Critical patent/EP0803579A1/fr
Publication of EP0803579A4 publication Critical patent/EP0803579A4/fr
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/10—Handling in a vacuum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B9/00—General processes of refining or remelting of metals; Apparatus for electroslag or arc remelting of metals
    • C22B9/04—Refining by applying a vacuum
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D27/00—Stirring devices for molten material
    • F27D27/005—Pumps
    • F27D27/007—Pulsating pumps

Definitions

  • This invention relates to ferrous metallurgy and, moreparticularly, the invention relates to methods of vacuum refining of metal and to devices for performing these methods.
  • the prior art method features inadequate refining of the molten metal, because the effect of pressure pulsation does not penetrate to a required depth, from which the growth of gas bubbles of a necessary size is provided.
  • this method does not realize the process of rectified diffusion, which also contributes to the growth of the bubbles and has no effect on the "buffer" surface layer of fine gas bubbles in the melt.
  • This device realizing the above mentioned method does not allow one to maintain stable conditions of the treatment with variable gas evolution from the metal and cannot operate with heating by high-temperature gases being evacuated from the container.
  • Also known in the art is a method of vacuum refining of metal, in which the pressure of a gas mixture above the metal surface is reduced to a valuesufficient for producing partial pressures of the gases above the melt, said pressure being lower than the partial pressure of the gases in the melt, and the metal is acted on by pressure pulsations (RU, A, 1441809).
  • a vacuum is produced above the melt surface, said vacuum pulsating in a high frequency range.
  • This method does not provide a required degree of metal refining, because the depth of treatment is inadequate.
  • this method does not realize the rectified diffusion process, while the process of floating up and fragmentation of the bubbles features low intensity and generally does not allow a metal of a required quality to be obtained.
  • This device realizing the above method also includes a tuyere for blowing the melt with an inert gas.
  • This device inconvenient, and unreliable in operation and has relatively low efficiency.
  • the basic object of the invention was to provide a method of vacuum refining of metal having such regimes of pressure pulsations that would enable one to obtain a metal of a required quality, and to provide a device for vacuum refining of metal effecting the above method that would be convenient and reliable in operation and have the maximum possible efficiency.
  • This object is attained by providing a method of vacuum refining of metal, in which the pressure of a mixture of gases above the molten metal is reduced to a pressure sufficient for producing the partial pressures of the gases above the melt lower than the partial pressures of the gases in the melt, and the metal is treated by pressure pulses; according to the invention, the pressure above the melt surface is varied with an amplitude of 0.02-0.08 MPa in a low-frequency range of 0.03-5 Hz and, in addition, the pressure is simultaneously varied in a medium-frequency range of 55-195 Hz with an amplitude of 0.005-0.01 MPa, and in a high-frequency range of 350-3500 Hz with an amplitude of 0.0001-0.001 MPa.
  • the same method is suitable for treatment of individual portions of metal periodically taken from the total volume of metal.
  • a device for vacuum refining of metal effecting the said method comprising a vacuum-tight container, having a gas-exhaust nipple, and an ejector, having a housing, a nozzle and a mixing channel and mounted on the gas-exhaust nipple;
  • the device is equipped with a unit for producing low-frequency pulsations of the working gas flow rate in the ejector nozzle, a unit for producing medium-frequency pulsations of gas flow rate at the inlet of the gas-exhaust nipple, and a unit for producing high-frequency pulsation of the flow rate of the gas evacuated from the container made as a controller varying the flow section of the nozzle and/or mixing channel of the ejector according to the following expression:
  • F a K 1 ⁇ F c 2 /F where F a is the cross-sectional area of the mixing channel; K 1 is the coefficient frown 0.5 to 0.7;
  • F a K 1 ⁇ F
  • the regulator for varying the flow section of the ejector nozzle can be made as a set of nozzles.
  • the regulator for varying the flow section of the nozzle and/or mixing channel of the ejector can also be made in the form of an insert mounted on the inner surface of the nozzle and/or mixing channel of the ejector.
  • the insert of the regulator varying the flow section of the ejector mixing channel can be made as a conical member with a taper angle of 1-3° whose narrowing part extends towards the mixing channel outlet.
  • the advantages of the claimed method consist in that its realization allows one to significantly reduce the content of residual dissolved gases and nonmetallic inclusions in the metal due to an increase of the depth of treatment of the melt in the container, organization of a rectified diffusion process, intensification of the floating function of the bubbles, reduction of the resistance to the evolution of gases from the metal and passing them through a slag layer, all these facts allowing the metal of a preset quality to be obtained.
  • the claimed device effecting the method, according to the invention makes it possible to obtain all regimes of pressure pulsations corresponding to the physical and chemical characteristics of the melt being treated.
  • the device utilizes the working gas energy with maximum efficiency due to minimization of losses by selecting optimum geometry along the gas-dynamic duct and using the automatic adjustment phenomenon following the changes in the evolution of the gas from the melt.
  • the claimed device is long-life and reliable in operation, because the basic units have no contact with the high temperature gases evacuated from the vacuum chamber and has maximum possible efficiency.
  • the claimed method of vacuum refining of metal consists in that supplied into a container with molten metal is a working gas having predetermined parameters, the pressure of gaseous mixture above the melt surface is reduced within 2-5 seconds to a pressure sufficient for producing partial pressures of the gases in the melt, and the metal is treated by pressure pulsations.
  • the pressure above the melt surface is varied with an amplitude of 0.02-0.08 MPa in a low-frequency range of 0.03-5 Hz and, at the same time, the pressure is varied in a medium-frequency range of 55-195 Hz with an amplitude of 0.005- 0.01 MPa, and in a high-frequency range of 350-3500 Hz with an amplitude of 0.0001-0.001 Hz.
  • the low-frequency component in a range of 0.03-5 Hz with an amplitude of 0.02-0.08 Mpa leads to such a phenomenon that during the pressure decrease the bubbles of CO or inert gas expand and during the pressure increase they compress.
  • the diffusion flow is directed into the bubbles while during the compression it is directed to outside, however, the former process is much more intensive and leads to a fast growth of the bubble.
  • the bubble pulsation results in permanent renewal of the melt in its boundary layer; when the bubble reaches the resonance size, it disintegrates into smaller bubbles which start grow as well.
  • the low-frequency pulsations of the pressure above the melt surface generate vacuum and pressure waves in the melt itself.
  • a frequency range of 0.03-5 Hz is selected, overlapping the band of resonance frequencies of the containers with the melt having a depth of 0.5 to 4 m with a gas content from 0 to 50%, the amplitude of pulsations below 0.02 MPa does not result in significant intensification of the process of rectified diffusion of gas in the molten metal, whereas the amplitude above 0.08 MPa increases the energy consumption and reduces the resistance of the vacuum-tight container.
  • the pressure pulsation component in a frequency range of 55-195 Hz with an amplitude of 0.005-0.02 MPa generates in (the region of the container walls intensive microflows which break the formed and newly forming bubbles.
  • this component affects the oscillation and fragmentation of the bubbles resonant to the given frequency range.
  • the parameters of the pressure pulsation at the medium frequencies are associated with the velocity of the melt microflows near the walls, which correspond to the rate of roughness of the walls, and the rate of cavitation strength of the melt associated with its temperature and composition.
  • the high frequency pressure pulsations in a range of 350-3500 Hz with an amplitude of pressure 0.0001-0.001 MPa result in oscillation and fragmentation of the bubbles of a different diameter having already floating on the metal surface and forming the so called "buffer layer" preventing the hydrogen diffusion from the upper metal layer due to a low pressure above the metal surface.
  • the hydrogen diffusion from the upper layer when realizing the method, has a significant effect on the total intensity of refining the entire metal, because a high amplitude of the CO bubbles under the pressure pulsation acting through the whole volume of the melt produces intensive ascending streams delivering the metal from the deep layers to the surface, i.e. the hydrogen-free layers are being replaced continuously.
  • This device comprises a vacuum-tight container 1 (Fig. 1) having a gas-exhaust nipple 2, an ejector 3 having a housing 4, a nozzle 5 and a mixing channel 6 and mounted on the gas-exhaust nipple 2.
  • the operation of the ejector 3 depends on such characteristic geometric parameters as the cross-sectional area F a of the mixing channel 6, the critical section area F b of the nozzle 5 and the output cross-sectional area F c of the nozzle 5.
  • the device At the inlet of the nozzle 5 of the ejector 3 the device is provided with a unit 7 for producing low-frequency pulsations of the working gas flow rate through the nozzle 5, a unit 8 for producing medium-frequency pulsations of the gas flow rate at the inlet of the gas-discharge branch pipe 2 through the nozzle 9, and a unit 10 for producing high-frequency pulsations of the flow rate of the gas being evacuated from the container 1.
  • the regulator for varying the flow section of the nozzle 5, 11 ( Figure 2) of the ejector 3 is made in the form of a set of nozzles 5 and 11, where in Figure 1 the nozzle 5 has a greater flow section than the nozzle 11 in Figure 2.
  • the unit 7 is secured to the ejector 3 by a fastener 14, the elements of the ejector 3 are secured by means of fasteners 15, 16, 17, and the unit 8 is secured to the nozzle 9 by means of a fastener 18.
  • the regulator varying the flow section of the nozzle 19 is made in the form of an insert 20 mounted on the internal surface of the nozzle 19, as shown in Figure 3.
  • the regulator varying the flow section of the mixing channel 6 of the ejector 3 is made in the form of an insert 21 mounted on the internal surface of the mixing channel 6.
  • the varying the flow section of the nozzle 19 and mixing channel 6 of the ejector 3 is made in the form of two inserts 20 and 22 mounted, respectively, on the internal surface of the nozzle 19 and mixing channel 6.
  • the insert 22 is conical with a taper angle of 1-3°, the narrowing portion 23 of the insert 22 extending towards the outlet 24 of the channel 6.
  • the embodiment of the claimed device shown in Figure 6 performs one version of effecting the method, according to the invention, in which there are treated individual portions of metal periodically taken from the total volume of metal 26 placed in the container 27.
  • the vacuum-tight container 28 is immersed into the metal 26.
  • Figure 6 shows a device according to Figure 1 partially immersed into the metal 26.
  • any device according to Figures 2-5 can successfully be used for this purpose.
  • the unit 7 providing low-frequency pulsations changes the flow rate of the working gas through the nozzle 5 so that the ejection of the gases from the container 1 and, therefore, the pressure therein.
  • the unit 8 is used for producing the medium-frequency pulsations of the gas flow rate, and a gas jet is periodically blown into the gas-exhaust nipple 2 resulting in pressure pulsations in the container 1.
  • the flow section of the nozzle 5 is adjusted so that, when the working gas is supplied, the nozzle 5 forms a jet which interacts with the mixing channel 6 and performs the ejection of gases from the container 1. In so doing the flow rate of the gases ejected from the container 1 pulsates with a high frequency. Then the stream of a mixture of the working and ejected (passive) gas flow from the mixing channel 6 into the cylindrical channel 12.
  • the gas jet interacts with the walls of the channel 12 and with its throat 13 having an area of F c , a reduced pressure is produced at the output of the mixing channel 6 increasing the productivity and, therefore, efficiency of the claimed device effecting the method according to the invention.
  • the device of Figure 6 effecting the method, according to the invention, in a portion regime allows the metal 26 to be treated not in bulk but by separate portions of metals 25 within 10-300 seconds. During this period the processes originated by the proposed sequence of operations are over completely, while some nucleus of the bubbles remaining in this portion are discharged into the whole volume, in which intensive gas release and removal of non-metallic inclusions are initiated. Then a new portion of metal is sucked and the process is repeated.
  • the treatment is terminated upon reaching the required characteristics of the melt.
  • the processing time is determined in the run of experimental melts or by the express-analysis results.
  • the convenient and reliable device claimed for effecting the method according to the invention having maximum possible efficiency, enable one to produce a metal of a required quality.
  • the invention can be used in non-ferrous metallurgy when casting metals and alloys.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
EP94909359A 1994-01-19 1994-02-24 Dispositif d'affinage sous vide de metal et dispositif associe Withdrawn EP0803579A4 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
RU9494000727A RU2046149C1 (ru) 1994-01-19 1994-01-19 Способ вакуумного рафинирования металла и устройство для его осуществления
RU94000727 1994-01-19
PCT/RU1994/000034 WO1995020057A1 (fr) 1994-01-19 1994-02-24 Dispositif d'affinage sous vide de metal et dispositif associe

Publications (2)

Publication Number Publication Date
EP0803579A1 true EP0803579A1 (fr) 1997-10-29
EP0803579A4 EP0803579A4 (fr) 1998-04-22

Family

ID=20151322

Family Applications (1)

Application Number Title Priority Date Filing Date
EP94909359A Withdrawn EP0803579A4 (fr) 1994-01-19 1994-02-24 Dispositif d'affinage sous vide de metal et dispositif associe

Country Status (7)

Country Link
EP (1) EP0803579A4 (fr)
JP (1) JPH09508671A (fr)
KR (1) KR970700781A (fr)
CN (1) CN1145642A (fr)
FI (1) FI962894A (fr)
RU (1) RU2046149C1 (fr)
WO (1) WO1995020057A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998009421A2 (fr) * 1996-08-30 1998-03-05 Telefonaktiebolaget Lm Ericsson (Publ) Systeme et procede applicables a des interrogations entrantes et sortantes portant sur des services de commutation de messages
CN1853828B (zh) * 2000-06-22 2010-04-21 株式会社丰荣商会 容器
US8623114B2 (en) * 2010-02-16 2014-01-07 Praxair Technology, Inc. Copper anode refining system and method
RU2490341C1 (ru) * 2011-12-15 2013-08-20 Евгений Владимирович Андреев Способ рафинирования медного или никелевого сплавов или меди и установка для осуществления способа

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE753613C (de) * 1943-02-03 1953-02-23 Ig Farbenindustrie Ag Verfahren zum Entgasen von Fluessigkeiten und Metallschmelzen
GB823419A (en) * 1955-09-27 1959-11-11 Siemens Ag Improvements in or relating to the de-gassing of molten metal by vibration or acoustic irradiation
US3162908A (en) * 1956-08-02 1964-12-29 William J Ruano Apparatus for applying vacuum and super-sonic vibrations in castings steels

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1236541B (de) * 1958-02-25 1967-03-16 Friedrich Kocks Dr Ing Einrichtung zum Durchlaufentgasen von Stahl
US3798025A (en) * 1971-12-29 1974-03-19 Allegheny Ludlum Ind Inc Vacuum decarburization in rh and dh type degassing systems
US4057421A (en) * 1974-10-22 1977-11-08 Sumitomo Metal Industries Limited Process for vacuum decarburization of steel
CA1216430A (fr) * 1984-01-20 1987-01-13 Joseph A. Mulcahy Traitement sous vide de l'acier

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE753613C (de) * 1943-02-03 1953-02-23 Ig Farbenindustrie Ag Verfahren zum Entgasen von Fluessigkeiten und Metallschmelzen
GB823419A (en) * 1955-09-27 1959-11-11 Siemens Ag Improvements in or relating to the de-gassing of molten metal by vibration or acoustic irradiation
US3162908A (en) * 1956-08-02 1964-12-29 William J Ruano Apparatus for applying vacuum and super-sonic vibrations in castings steels

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9520057A1 *

Also Published As

Publication number Publication date
JPH09508671A (ja) 1997-09-02
RU2046149C1 (ru) 1995-10-20
CN1145642A (zh) 1997-03-19
WO1995020057A1 (fr) 1995-07-27
EP0803579A4 (fr) 1998-04-22
KR970700781A (ko) 1997-02-12
FI962894A (fi) 1996-09-18
FI962894A0 (fi) 1996-07-18

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