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EP0281508B1 - Dispositif pour dégazer du métal fondu - Google Patents

Dispositif pour dégazer du métal fondu Download PDF

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Publication number
EP0281508B1
EP0281508B1 EP88810019A EP88810019A EP0281508B1 EP 0281508 B1 EP0281508 B1 EP 0281508B1 EP 88810019 A EP88810019 A EP 88810019A EP 88810019 A EP88810019 A EP 88810019A EP 0281508 B1 EP0281508 B1 EP 0281508B1
Authority
EP
European Patent Office
Prior art keywords
molten metal
side wall
chamber
wall portion
disposed
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.)
Expired - Lifetime
Application number
EP88810019A
Other languages
German (de)
English (en)
Other versions
EP0281508A1 (fr
Inventor
Howard A. Mcdonald
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.)
3A Composites International AG
Original Assignee
Alusuisse Lonza Services Ltd
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 Alusuisse Lonza Services Ltd filed Critical Alusuisse Lonza Services Ltd
Priority to AT88810019T priority Critical patent/ATE64157T1/de
Publication of EP0281508A1 publication Critical patent/EP0281508A1/fr
Application granted granted Critical
Publication of EP0281508B1 publication Critical patent/EP0281508B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • C22B21/00—Obtaining aluminium
    • C22B21/06—Obtaining aluminium refining
    • C22B21/066—Treatment of circulating aluminium, e.g. by filtration
    • 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
    • C22B9/05—Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ
    • C22B9/055—Refining by treating with gases, e.g. gas flushing also refining by means of a material generating gas in situ while the metal is circulating, e.g. combined with filtration

Definitions

  • This invention relates to a device for degassing molten metal, comprising a chamber having an inner elongated sidewall portion and an outer elongated sidewall portion, a molten metal inlet arranged, with respect to the chamber, at a first level around molten metal to be introduced into the chamber such that the molten metal flows down through the chamber from the molten metal inlet, a molten metal outlet located at a second level below this first level to discharge the molten metal from the chamber, and at least a purge gas inlet attached to the inner elongated sidewall portion below the first height to introduce the purge gas into the chamber.
  • a method and apparatus for degassing the molten metal is known from US Pat. No. 4,177,066.
  • This patent teaches degassing molten metal by means of a vortex tank reactor, the molten metal being introduced tangentially into the reactor so that the molten metal flows in a vortex flow from the inlet of the reactor to the outlet thereof.
  • the metal inlet be arranged with respect to the chamber wall of the reactor such that the liquid is tangentially fed into the reactor.
  • the vortex tank reactor comprises a first elongated, essentially cylindrical side wall part and a second, underlying, narrowing side wall part below the first, essentially cylindrical wall part.
  • Purge gas inlet nozzles enter through the converging wall portion at different heights, so as to distribute the purge gas bubbles throughout the melt it flows from the reactor inlet to the outlet.
  • the flushing gas nozzles are arranged alternately at different distances from the central axis of the vortex tank reactor, the flushing gas bubble distribution being maximized.
  • a disadvantage of the known embodiments is that the devices have to be emptied after each use by draining the molten metal. Otherwise the standing metal cools down quickly and the entire degassing system would "freeze” i.e. the standing metal solidifies and can no longer be removed.
  • Another object of the present invention is to provide a device, as mentioned above, which can be operated in a space-saving manner and at low cost.
  • the inner and the outer side wall section are arranged at a spatial distance from one another and in the intermediate space formed thereby, heating devices, insulation between the heating devices and the outer side wall section and an air space is disposed between the heaters and the inner elongated sidewall portion.
  • the device of the present invention comprises a chamber with an inner elongated side wall part and a spatially separated outer elongated side wall part; a molten metal inlet located at a first level with respect to this chamber for introducing the molten metal into the chamber such that the molten metal flows down through the chamber from the inlet; a molten metal outlet disposed at a second height below the first height to discharge the molten metal from the chamber; at least one purge gas inlet, attached to the inner elongated sidewall portion, below the first height to introduce the purge gas into the chamber; Heaters in the space between the inner elongated sidewall portion and the outer elongated sidewall portion, spatially separated from the inner and outer sidewall portions; Isolation devices between the heaters and the outer side wall part, which preferably extend from the heaters to the outer side wall part and an air space between the heaters and the inner extended side wall part.
  • the heaters are located between the metal inlet and the metal outlet.
  • the device further preferably comprises a drain pipe below the metal outlet and a riser pipe opposite the chamber, which communicates with the metal outlet.
  • the metal inlet is positioned tangentially with respect to the chamber such that the molten metal flows in a vortex-shaped motion downward through the chamber from the molten metal inlet.
  • the device of the present invention is capable of keeping the treatment temperature within narrow limits, and has been found to be particularly advanced for the degassing of aluminum, as well as in the same sense other metals are used.
  • the device can be easily filled with molten metal with precise and effective temperature control, and the need to empty the device after each use is avoided.
  • the first metal exiting the device may be at a higher temperature than the metal in the holding furnace, thereby avoiding downstream cooling too quickly.
  • the device is an effective, cost-saving unit with moderate energy requirements.
  • application of the present device can result in a significant improvement in productivity without degradation in product quality.
  • Figures 1-3 show a vortex tank reactor 10 with a first, essentially cylindrical side wall part 12 and a second, below, narrowing down side wall part 14, the side wall parts together forming the degassing chamber 16.
  • the first side wall portion 12 is illustrated herein essentially in a cylindrical shape. It should be noted, however, that it may be in an octagonal shape or in any other shape that allows the metal to flow in a vortex-shaped manner as the metal passes through the degassing chamber 16.
  • molten metal enters through the molten metal inlet 18 at the top of the chamber 16, and the inlet 18 is tangent to the degassing chamber 16 and the molten metal leaves the chamber 16 through the molten metal outlet 20 at the bottom of the chamber 16. Accordingly, the molten metal enters the degassing chamber 16 tangentially and flows in a vortex-like manner through chamber 16 and flows out through the outlet 20.
  • a substantially cylindrical side wall portion 22 may be provided below the side wall portion 14 which narrows downward and may be adapted to receive a suitable filter medium.
  • FIG. 3 where the cylindrical sidewall portion 22 is internally provided with a peripheral rim or protrusion 24 located upstream of and in close proximity to the outlet 20.
  • This peripheral edge 24, as illustrated, represents a downwardly narrowing, beveled surface that enables the installation and replacement of a suitably designed, filter-like medium 26.
  • the filter-like medium 26 has a correspondingly beveled peripheral surface 28, equipped with a reshaping seal 30, which is fastened by means of pressure adjustment in order to sealingly adapt to the peripheral edge 24 in the side wall part 22.
  • the filter element does not necessarily have to be installed in the side wall section 22 and can be installed further downstream from the vortex tank reactor 10 and this last embodiment is also preferred.
  • an inert gas blanket of argon, nitrogen, etc. can be provided over the top of chamber 16 to minimize readsorption of gaseous contaminants on the metal surface.
  • the vortex tank reactor 10 is equipped with a first, essentially cylindrical side wall section 12 and a second, downwardly narrowing side wall section 14 arranged below the side wall section 12 so as to form the degassing chamber 16.
  • the downwardly narrowing sidewall portion 14 is provided on its peripheral surface with a plurality of purge gas inlet nozzles 32 for introducing the purge gas into the molten metal as the metal passes chamber 16 from tangential inlet 18 to outlet 20.
  • the nozzles 32 are arranged at different heights of the peripheral surface of the side wall section 14.
  • the purge gas nozzle tips can not only be installed in the narrowed sidewall section 14 as illustrated, but similar results can be achieved by installing a first set nozzle tips in sidewall section 12 and a second set of nozzle tips in sidewall section 14.
  • the device of the present invention can use a purge gas such as an inert gas, preferably containing a small amount of an active gas component such as chlorine or a fully halogenated carbon component.
  • a purge gas such as an inert gas, preferably containing a small amount of an active gas component such as chlorine or a fully halogenated carbon component.
  • the gas used can be any of the gases or mixtures thereof, such as nitrogen, argon, chlorine, carbon monoxide, Freon 12, etc., which are known and suitable per se for degassing.
  • nitrogen and dichlorodifluoromethane, argon and dichlorodifluoromethane, nitrogen and chlorine or argon and chlorine can be used for the degassing of molten aluminum.
  • the degassing chamber 16 is equipped with an inner elongated side wall section 40 and an outer elongated side wall section 41, spaced apart from the inner sidewall.
  • the molten metal inlet 18 is tangentially located at a first height with respect to chamber 16 to introduce the molten metal into chamber 16 such that the molten metal flows downward through the chamber in a vortex-shaped manner.
  • the metal outlet 20 is mounted at a second height below the first height to discharge the molten metal from the chamber 16. It should be noted that the embodiment according to FIGS. 4 and 5 does not include the filter medium, which, if used, is preferably used in the metal flow direction downstream of the reactor.
  • a plurality of purge gas nozzles 32 are attached to the inner sidewall portion 40 below the metal inlet 18 and above the metal outlet 20 to direct the purge gas into the chamber 16, countercurrent to the molten one Introduce metal that flows downward in a vortex-shaped manner from inlet 18 to outlet 20.
  • the number of nozzles depends on the size of the unit and the desired throughput, and a purge gas nozzle number of 2-30 is very suitable. 6 or 8 purge gas nozzles have been found to give excellent results.
  • Inner sidewall portion 40 should be constructed of a suitable material that resists the molten metal, such as a refractory material such as alumina or silicon carbide.
  • the outer side wall section 41 should be constructed from a suitable, high-strength material such as steel. The inner and outer side walls are spatially separated from one another and insulation material 42 is attached between them.
  • heaters 43 are disposed in the space between the inner and outer side walls, separated from both the inner and outer side walls, as clearly shown in Figures 4 and 5.
  • Insulation material 42 is disposed between heater 43 and outer side wall 41, which preferably fills the entire space therebetween, and an air or heating space 44 is provided between heaters 43 and inner wall 40.
  • a plurality of heaters 43 are provided depending on the size of the unit. It has been found that the separation of the heater 43 from the inner wall 40 by means of an air space therebetween ensures surprisingly effective and uniform heating, regardless of the difficult conditions in the degassing device itself.
  • the heating device 43 is arranged between the inlet 18 and the outlet 20. Accordingly, any suitable heating element can be used; a typical element is a nickel-chrome element with a large diameter, with a maximum of 45 Volt, 3-phase and fed with 60 Hertz.
  • the heating elements are connected to the power supply (not shown) via ring line 45 with a typical power supply for 480 volts, 3-phase and 60 Hertz with reducing transformers in order to supply low voltage and high current to the heating elements.
  • the outlet 20 is connected to an integrated riser 46 and then to the pouring station and, if provided, there is a filter in between.
  • the integrated riser pipe is located opposite the chamber 16 with an inner riser pipe wall 47, an outer riser pipe wall 48, heating element 43 at a spatial distance from the two, the inner and the outer, riser pipe walls.
  • An insulation 42 is located between the heating element 43 and the outer riser wall 48 and with an air space 44 between the heating element 49 and the inner riser wall 47, a heated riser is formed.
  • the drain pipe 52 with the drain opening 53 and the closure device 54 to be opened is attached below the outlet 20, preferably with two drain openings and two closure devices to be opened, as shown in FIG. 4, for easier cleaning.
  • the device according to the present invention has important advantages.
  • the device is compact in size and versatile in design.
  • the device's heated chamber keeps maintenance costs low, simplifies application procedures, and improves productivity.
  • it has been found that the energy costs to be used are surprisingly low.
  • the device In use, the device easily maintains the metal temperature at 690 ° C to 704 ° C, while the temperature of the housing is about 93 ° C.
  • the temperature stabilize the empty chamber first before pouring the molten metal.
  • the temperature of the filled chamber can be set to the temperature required for the start of pouring.
  • the gas flow is increased from a basic setting to the purging setting.
  • the gas flow is reset to the basic setting. Should a nozzle replacement be necessary, this can usually be done in a few minutes after the system has been emptied. The temperature can be maintained during this time, which allows nozzle replacement during each scheduled system drain.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)

Claims (8)

1. Dispositif de dégazage de métal fondu, comprenant une chambre possédant une portion de paroi latérale prolongée interne et une portion de paroi latérale prolongée externe, une entrée pour métal fondu, disposée à un premier niveau par rapport à la chambre pour introduire le métal fondu dans la chambre de sorte que le métal fondu issu de l'entrée pour métal fondu traverse la chambre d'amont en aval, une sortie pour le métal fondu disposée à un second niveau inférieur à ce premier niveau pour évacuer le métal fondu de la chambre, au moins une entrée de gaz de circulation ménagée sur la portion de paroi latérale prolongée interne à un niveau inférieur au premier niveau, pour introduire le gaz de circulation dans la chambre,
caractérisé en ce que,
les portions de paroi latérale interne et externe sont disposées à distance l'une de l'autre et que se trouvent dans l'espace intermédiaire formé des dispositifs de chauffage, une isolation entre les dispositifs de chauffage et la portion de paroi latérale externe et un espace d'air entre les dispositifs de chauffage et la portion de paroi latérale prolongée interne.
2. Dispositif selon la revendication 1, caractérisé en ce que l'isolation s'étend des dispositifs de chauffage à la portion de paroi latérale prolongée externe.
3. Dispositif selon les revendications 1 et 2, caractérisé en ce que les dispositifs de chauffage sont disposés à un niveau situé entre l'entrée métal et la sortie métal.
4. Dispositif selon les revendications 1 à 3, caractérisé en ce qu'est disposée une conduite d'évacuation en dessous de la sortie métal.
5. Dispositif selon la revendication 4, caractérisé en ce que la conduite d'évacuation présente deux orifices d'évacuation distincts, dont chacun possède un dispositif de fermeture.
6. Dispositif selon les revendications 1 à 5, caractérisé en ce qu'est disposée une conduite ascendante pour le métal fondu communiquant avec la sortie pour le métal fondu.
7. Dispositif selon la revendication 6, caractérisé en ce que la conduite ascendante présente une portion de paroi latérale de conduite ascendante prolongée interne et une portion de paroi latérale de conduite ascendante prolongée externe séparée de la portion interne par un espace, et des dispositifs de chauffage disposés dans l'espace situé entre la portion de paroi latérale de conduite ascendante prolongée interne et la portion de paroi latérale de conduite ascendante prolongée externe, séparés par un espace tant de la portion de paroi latérale de conduite ascendante interne que de la portion de paroi latérale de conduite ascendante externe.
8. Dispositif selon les revendications 1 à 7, caractérisé en ce que l'entrée métal est disposée tangentiellement par rapport à la chambre de sorte que le métal fondu issu de l'entrée pour le métal fondu traverse la chambre d'amont en aval d'un mouvement tourbillonnaire.
EP88810019A 1987-02-03 1988-01-15 Dispositif pour dégazer du métal fondu Expired - Lifetime EP0281508B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT88810019T ATE64157T1 (de) 1987-02-03 1988-01-15 Vorrichtung fuer die entgasung von geschmolzenem metall.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US07/010,463 US4744545A (en) 1987-02-03 1987-02-03 Apparatus for degassing molten metal
US10463 1987-02-03

Publications (2)

Publication Number Publication Date
EP0281508A1 EP0281508A1 (fr) 1988-09-07
EP0281508B1 true EP0281508B1 (fr) 1991-06-05

Family

ID=21745879

Family Applications (1)

Application Number Title Priority Date Filing Date
EP88810019A Expired - Lifetime EP0281508B1 (fr) 1987-02-03 1988-01-15 Dispositif pour dégazer du métal fondu

Country Status (12)

Country Link
US (1) US4744545A (fr)
EP (1) EP0281508B1 (fr)
JP (1) JPS63195229A (fr)
AR (1) AR240066A1 (fr)
AT (1) ATE64157T1 (fr)
AU (1) AU599450B2 (fr)
BR (1) BR8800490A (fr)
CA (1) CA1315104C (fr)
DE (1) DE3863092D1 (fr)
ES (1) ES2023009B3 (fr)
NO (1) NO168778C (fr)
ZA (1) ZA88542B (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4009833C2 (de) * 1989-03-31 1996-09-26 Aisan Ind Luftmengenmeßeinrichtung für Ansaugluft
US5024696A (en) * 1990-07-23 1991-06-18 Alusuisse-Lonza Services Ltd. Apparatus and method for degassing molten metal
GB9610180D0 (en) * 1996-05-15 1996-07-24 English Christopher J Trough degassing reactor

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3039864A (en) * 1958-11-21 1962-06-19 Aluminum Co Of America Treatment of molten light metals
GB1148344A (en) * 1967-01-24 1969-04-10 Foseco Int Method for the removal of inclusions from molten metals by filtration
BE756091A (fr) * 1969-09-12 1971-02-15 Britsh Aluminium Cy Ltd Procede et dispositif pour le traitement de metal
US4021026A (en) * 1974-12-23 1977-05-03 Union Carbide Corporation Protection for externally heated cast iron vessel used to contain a reactive molten metal
US4052199A (en) * 1975-07-21 1977-10-04 The Carborundum Company Gas injection method
US4040610A (en) * 1976-08-16 1977-08-09 Union Carbide Corporation Apparatus for refining molten metal
US4169584A (en) * 1977-07-18 1979-10-02 The Carborundum Company Gas injection apparatus
US4179102A (en) * 1978-06-12 1979-12-18 Swiss Aluminium Ltd. Apparatus for the degassing and filtration of molten metal
US4177066A (en) * 1978-06-12 1979-12-04 Swiss Aluminium Ltd. Method and apparatus for the removal of impurities from molten metal
FR2463816A1 (fr) * 1979-08-24 1981-02-27 Servimetal Cartouche pour filtration active et traitement des metaux et alliages liquides
US4392636A (en) * 1981-07-22 1983-07-12 Swiss Aluminium Ltd. Apparatus for degassing molten metal
US4494735A (en) * 1983-11-16 1985-01-22 Swiss Aluminium Ltd. Apparatus for degassing molten metal

Also Published As

Publication number Publication date
NO880438L (no) 1988-08-04
CA1315104C (fr) 1993-03-30
EP0281508A1 (fr) 1988-09-07
BR8800490A (pt) 1988-06-14
AR240066A1 (es) 1990-01-31
US4744545A (en) 1988-05-17
ES2023009B3 (es) 1991-12-16
AU599450B2 (en) 1990-07-19
NO880438D0 (no) 1988-02-01
ATE64157T1 (de) 1991-06-15
ZA88542B (en) 1988-09-28
JPS63195229A (ja) 1988-08-12
NO168778C (no) 1992-04-01
JPH0338326B2 (fr) 1991-06-10
AU1061088A (en) 1988-08-04
DE3863092D1 (de) 1991-07-11
NO168778B (no) 1991-12-23

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