EP0385617A1 - Injecting gas into molten metal - Google Patents

Injecting gas into molten metal Download PDF

Info

Publication number
EP0385617A1
EP0385617A1 EP90301657A EP90301657A EP0385617A1 EP 0385617 A1 EP0385617 A1 EP 0385617A1 EP 90301657 A EP90301657 A EP 90301657A EP 90301657 A EP90301657 A EP 90301657A EP 0385617 A1 EP0385617 A1 EP 0385617A1
Authority
EP
European Patent Office
Prior art keywords
passageway
molten metal
gas
media disperser
openings
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Withdrawn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
EP90301657A
Other languages
German (de)
English (en)
French (fr)
Inventor
Ronald E. Gilbert
George S. Mordue
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.)
Unifrax 1 LLC
Original Assignee
Carborundum Co
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 Carborundum Co filed Critical Carborundum Co
Publication of EP0385617A1 publication Critical patent/EP0385617A1/en
Withdrawn legal-status Critical Current

Links

Images

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
    • 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
    • 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
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/072—Treatment with gases

Definitions

  • the invention relates to techniques for injecting gas into molten metal and, more particularly, to a technique for uniformly injecting gas into molten metal being pumped through a passageway.
  • gases such as nitrogen, chlorine, and argon
  • gases such as nitrogen, chlorine, and argon
  • gases added to the molten metal chemically react with the undesired constituents to convert them to a form (such as a precipitate, a dross, or an insoluble gas compound) that can be separated readily from the remainder of the molten metal.
  • molten metal will be understood to mean any metal such as aluminum, magnesium, copper, iron, and alloys thereof, which are amenable to gas purification.
  • gas will be understood to mean any gas or combination of gases, including argon, nitrogen, chlorine, freon, sulfur hexafluoride, and the like, that have a purifying effect upon molten metals with which they are mixed.
  • gas injection typically is accomplished by immersing a molten metal pump into the molten metal, and by injecting gas through a conduit into the outlet passageway of the pump.
  • Suitable gas injection pumps of the type described are available commercially from Metaullics Systems, 31935 Aurora Road, Solon, Ohio 44139, under the model designation M30-­CSD-Cl2, et al.
  • the gas is injected through a so-called flux tube, or injection tube having an inner diameter of approximately one-half inch.
  • the flux tube is connected to the discharge passageway of the pump along the upper side of the passageway.
  • the gas would be injected uniformly into the molten metal in the form of very small incipient bubbles so that intimate mixing of the gas and molten metal would occur as quickly as possible. It also would be desirable to be able to inject small bubbles and disperse them as rapidly as possible at all pump speeds, including very low speeds.
  • Apparatus according to the invention includes a passageway through which molten metal can be passed.
  • a plurality of openings are disposed about the periphery of the passageway, and a means for injecting gas through the openings is provided.
  • the passageway constitutes the outlet of a molten metal pump, and the openings are defined by a porous media disperser that is disposed within the passageway so as to form a portion of the inner wall of the passageway.
  • the media disperser preferably is made from bonded ceramic grain porous media, but it can be made from other materials, including graphite.
  • the means for injecting gas includes a circumferential groove formed about the media disperser, the groove being in fluid communication with a source of compressed gas.
  • the invention also includes a method for injecting gas into molten metal that comprises the steps of passing the molten metal through a passageway having a predetermined cross-section, providing a plurality of openings in the passageway about the periphery of the passageway, and injecting gas into the molten metal through the openings of the passageway.
  • the cross-section defines a circle, and the openings are defined by a porous ceramic media disperser.
  • the gas is injected into the molten metal uniformly about the periphery of the passageway. Moreover, because the gas is passed through a porous media disperser, exceedingly small bubbles of gas are discharged into the molten metal. By injecting very small bubbles and by injecting them uniformly about the periphery of the passageway, the gas is intimately mixed with the molten metal in a very short period of time. Excellent results are obtained at all pump speeds.
  • a gas injection apparatus is indicated generally by the reference numeral 10.
  • the apparatus 10 is in the form of a pump that is adapted to be immersed in molten metal contained within a vessel 14.
  • the vessel 14 can be any container containing molten metal that is desired to be purified, although it is expected that the vessel 14 will be the external well of a reverberatory furnace.
  • the pump can be any type of pump suitable for pumping molten metal.
  • the pump will have a base member 16 within which an impeller 18 is disposed.
  • the base member 16 includes an outlet passageway 20.
  • a fitting 22 is secured to the base member 16, the fitting including a passageway 24 that is aligned with the outlet passageway 20.
  • a sleeve 26 is secured to the fitting 22 by means of a threaded connection indicated at 28.
  • a fluid-tight seal is effected by refractory cement indicated by the reference numeral 29.
  • the sleeve 26 is hollow so as to define a longitudinally extending bore 30.
  • the bore 30 is axially aligned with the passageway 24.
  • a porous ceramic media disperser 32 in the form of a ring is disposed within the fitting 22, and is held in place there by the sleeve 26.
  • the media disperser 32 is compressed against a shoulder 34 formed within the fitting 22, the compression being accomplished by the end of the sleeve 26.
  • a circumferential groove 36 is formed in the fitting 22 about the outer periphery of the media disperser 32.
  • the fitting 22 includes a passageway 38 that is in fluid communication with the groove 36.
  • the base member 16 includes a passageway 40 that is in fluid communication with the passageway 38.
  • a gas injection conduit 42 is connected to the base member 16.
  • the conduit 42 includes an internal passageway 44 that is in fluid communication with the passageway 40 and with a source of compressed gas (not shown).
  • the conduit 42 also functions as a support for the base member 16.
  • the media disperser 32 preferably is made from bonded ceramic grain porous media commercially available from Metaullics Systems of Solon, Ohio.
  • a variety of materials can be used to make the media disperser 32. It has been found that glass frit-bonded aluminum oxide or glass frit-bonded silicon carbide works especially well when injecting inert gases such as nitrogen, argon, or sulfur hexafluoride into molten aluminum, magnesium, copper, or alloys thereof.
  • a porous graphite media disperser or a sintered oxide-based ceramic media disperser may be used when the gas being injected is chlorine.
  • the size and number of the openings in the media disperser 32 are important because they determine, in large measure, the size of the bubbles that are injected into the molten metal discharged by the pump 10.
  • Commercially available porous media dispersers that provide acceptable gas flow rates and small bubble size have pore diameters in the range of 10-100 microns. Gas flow rates and volumes are dependent upon the size of the media disperser and applied pressure. Those skilled in the art will be able to select appropriate media dispersers to suit their particular needs.
  • FIG. 4 An alternative embodiment of the invention is illustrated in Figure 4.
  • the fitting 22 is replaced by a fitting 50.
  • the fitting 50 is substantially similar to the fitting 22, and like elements are indicated by like reference numerals carried over from Figures 2 and 3.
  • the embodiment shown in Figure 4 employs a passageway 52 which opens into a counterbored portion 54.
  • a gas injection conduit 56 having an internal passageway 58 is secured within the counterbored portion 54 so that the passageways 52, 58 are in fluid communication with each other.
  • the embodiment of the invention illustrated in Figure 4 thus is usable with a molten metal pump of virtually any type, provided the fitting 50 can be secured to the outlet of the pump.
  • gas is injected into the molten metal uniformly about the periphery of the passageway 24.
  • the bubbles that are injected are very small, and they become intimately mixed with the molten metal flowing through the passageway 24 and the bore 30.
  • the only significant limitation on the sleeve 26 is that it should be long enough to ensure complete mixing of the gas and the molten metal.
  • the media disperser 32 is formed of a ceramic material, it withstands very well the corrosive and erosive action of the molten metal. Additionally, because the sleeve 26 is threaded into the fitting 22, the media disperser 32 can be replaced conveniently when necessary.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Nozzles (AREA)
  • Mold Materials And Core Materials (AREA)
EP90301657A 1989-02-17 1990-02-15 Injecting gas into molten metal Withdrawn EP0385617A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US31289389A 1989-02-17 1989-02-17
US312893 1989-02-17

Publications (1)

Publication Number Publication Date
EP0385617A1 true EP0385617A1 (en) 1990-09-05

Family

ID=23213482

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90301657A Withdrawn EP0385617A1 (en) 1989-02-17 1990-02-15 Injecting gas into molten metal

Country Status (10)

Country Link
EP (1) EP0385617A1 (no)
JP (1) JPH02290930A (no)
KR (1) KR900013092A (no)
AU (1) AU4988890A (no)
BR (1) BR9000732A (no)
CA (1) CA2010235A1 (no)
HU (1) HUT57277A (no)
IL (1) IL93349A0 (no)
NO (1) NO900760L (no)
PT (1) PT93185A (no)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2670839A1 (fr) * 1990-12-21 1992-06-26 Cit Alcatel Machine, telle que pompe a vide ou compresseur du type volumetrique ou a entrainement.
WO1996030143A1 (en) * 1995-03-29 1996-10-03 The University Of Queensland Method of fluid dispersion and apparatus therefor
CN108396109A (zh) * 2017-02-05 2018-08-14 鞍钢股份有限公司 一种在钢包钢液内产生弥散气泡的方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2652018B1 (fr) * 1989-09-20 1994-03-25 Pechiney Rhenalu Dispositif de traitement au moyen de gaz d'un bain liquide d'aluminium de grande surface maintenu a l'etat stationnaire dans un four.

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3715112A (en) * 1970-08-04 1973-02-06 Alsacienne Atom Means for treating a liquid metal and particularly aluminum
US4052199A (en) * 1975-07-21 1977-10-04 The Carborundum Company Gas injection method
US4295883A (en) * 1979-07-10 1981-10-20 Swiss Aluminium Ltd. Device and method for introducing gases into molten metal
US4351514A (en) * 1980-07-18 1982-09-28 Koch Fenton C Apparatus for purifying molten metal
EP0171589B1 (en) * 1984-07-18 1988-05-04 RADEX ITALIANA S.p.A. Collector nozzle in a device for controlling the outflow of cast steel from a ladle or from a tundish

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3715112A (en) * 1970-08-04 1973-02-06 Alsacienne Atom Means for treating a liquid metal and particularly aluminum
US4052199A (en) * 1975-07-21 1977-10-04 The Carborundum Company Gas injection method
US4295883A (en) * 1979-07-10 1981-10-20 Swiss Aluminium Ltd. Device and method for introducing gases into molten metal
US4351514A (en) * 1980-07-18 1982-09-28 Koch Fenton C Apparatus for purifying molten metal
EP0171589B1 (en) * 1984-07-18 1988-05-04 RADEX ITALIANA S.p.A. Collector nozzle in a device for controlling the outflow of cast steel from a ladle or from a tundish

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2670839A1 (fr) * 1990-12-21 1992-06-26 Cit Alcatel Machine, telle que pompe a vide ou compresseur du type volumetrique ou a entrainement.
EP0492332A1 (fr) * 1990-12-21 1992-07-01 Alcatel Cit Pompe à vide avec injection de gaz sec
US5234323A (en) * 1990-12-21 1993-08-10 Alcatel Cit Fluid positive displacement machine with gas injection in the discharge region
WO1996030143A1 (en) * 1995-03-29 1996-10-03 The University Of Queensland Method of fluid dispersion and apparatus therefor
CN108396109A (zh) * 2017-02-05 2018-08-14 鞍钢股份有限公司 一种在钢包钢液内产生弥散气泡的方法

Also Published As

Publication number Publication date
NO900760L (no) 1990-08-20
CA2010235A1 (en) 1990-08-17
HUT57277A (en) 1991-11-28
HU900835D0 (en) 1990-05-28
BR9000732A (pt) 1991-01-22
PT93185A (pt) 1991-10-15
IL93349A0 (en) 1990-11-29
JPH02290930A (ja) 1990-11-30
KR900013092A (ko) 1990-09-03
NO900760D0 (no) 1990-02-16
AU4988890A (en) 1990-08-23

Similar Documents

Publication Publication Date Title
US5662725A (en) System and device for removing impurities from molten metal
US4351514A (en) Apparatus for purifying molten metal
US10640846B2 (en) Ultrasonic degassing of molten metals
US9435343B2 (en) Gas-transfer foot
US12031550B2 (en) Tensioned support post and other molten metal devices
US4898367A (en) Dispersing gas into molten metal
US6027685A (en) Flow-directing device for molten metal pump
US20180178281A1 (en) Transfer pump launder system
US8178037B2 (en) System for releasing gas into molten metal
US6123523A (en) Gas-dispersion device
AU2018202195B2 (en) Ultrasonic Probes With Gas Outlets For Degassing Of Molten Metals
CA1074695A (en) Method and apparatus for recovering metal values from mineral ores by in-situ mining
US4295883A (en) Device and method for introducing gases into molten metal
EP0385617A1 (en) Injecting gas into molten metal
KR850004031A (ko) 바닥 주입 용기의 맴돌이 방지 방법 및 장치
US4767036A (en) Apparatus and method for emptying metallurgical vessels containing metal and slag
SE452989B (sv) Dysa for injicering av gas i smelt metall
US4754954A (en) Refractory device for introducing a gas into a molten metal and a method for making the device
US4148468A (en) Lance for the flush gas treatment of non-ferrous molten metals
US20070108673A1 (en) Molten metal processing
EP1625239A1 (en) Improvements in and relating to molten metal processing
Steinmetz et al. Investigation of Flow Conditions in a Porous Plug Ladle
PL181996B1 (pl) Urządzenie do prowadzenia procesów pomiędzy gazem a cieczą lub zawiesiną
JPS6263612A (ja) 炉の無酸化出鋼口
JPS6152980A (ja) 脱ガス方法及び装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IT LI LU NL SE

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: THE CARBORUNDUM COMPANY

17P Request for examination filed

Effective date: 19910225

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19910308

R18W Application withdrawn (corrected)

Effective date: 19910308