[go: up one dir, main page]

US3472432A - Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle - Google Patents

Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle Download PDF

Info

Publication number
US3472432A
US3472432A US717033A US3472432DA US3472432A US 3472432 A US3472432 A US 3472432A US 717033 A US717033 A US 717033A US 3472432D A US3472432D A US 3472432DA US 3472432 A US3472432 A US 3472432A
Authority
US
United States
Prior art keywords
stopper head
receptacle
nozzle
molten metal
coating
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
US717033A
Inventor
Ronald V Kilgore
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.)
Vesuvius Crucible Co
Original Assignee
Vesuvius Crucible 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 Vesuvius Crucible Co filed Critical Vesuvius Crucible Co
Application granted granted Critical
Publication of US3472432A publication Critical patent/US3472432A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D41/00Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
    • B22D41/14Closures
    • B22D41/16Closures stopper-rod type, i.e. a stopper-rod being positioned downwardly through the vessel and the metal therein, for selective registry with the pouring opening
    • B22D41/18Stopper-rods therefor

Definitions

  • a coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle comprising a stopper head body with a coating thereon so that when the stopper head is in position closing the nozzle and molten metal is introduced into the relatively cold receptacle metal freezes in the bottom of the receptacle and against the coating of the stopper head, the coating being of friable refractory material which fragments when subjected to tensile and/or shear stresses so that when the stopper head is subsequently urged upwardly to permit outflow of molten metal through the nozzle the coating fragments, freeing the stopper head, obviating freezing of the stopper head to solidified metal in the bottom of the receptacle.
  • the coating preferably comprises finely divided refractory material and a binder and may be of such consistency that it may be applied with a brush.
  • the refractory material of the coating is of such character that it does not sinter at the temperature of the molten metal.
  • An unfired refractory powder is preferably employed.
  • the coating is formed in situ on the stopper head body.
  • This invention relates to a coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle. While the invention is of wide application it has especial utility in stopper heads for bottom pour receptacles for pouring or teeming molten metal such as bottom pour ladles and tundishes used for pouring or teeming molten steel either into ingot molds or into continuous casting apparatus.
  • a stopper head for a bottom pour molten steel ladle or tundish For purposes of explanation and illustration the invention will be described as applied to a stopper head for a bottom pour molten steel ladle or tundish.
  • molten steel at a temperature of the order of 2900 F. is introduced into a relatively cold receptacle such as a ladle or tundish having a nozzle in its bottom which is initially closed by a stopper head (see, for example, United States Patent No. 3,352,534)
  • the great difference in temperature between the incoming molten steel on the one hand and the receptacle, including the nozzle and stopper head, on the other hand is so great that some of the molten steel freezes in the bottom of the receptacle.
  • a coated stopper head comprising a stopper head body with a coating thereon so that when the stopper head is in position closing the nozzle and molten metal is introduced into the relatively cold receptacle the molten metal in the bottom of the receptacle freezes against the coating of the stopper head rather than against the body of the stopper head itself;
  • the coating is of friable refractory material which fragments when subjected to tensile and/ or shear stresses so that when the stopper head is subsequently urged upwardly to permit outflow of molten metal through the nozzle the coating fragments, freeing the stopper head, obviating freezing of the stopper head to solidified metal in the bottom of the receptacle.
  • the coating acts in the nature of a friable shell like an egg shell sothat when the stopper head is raised the shell disintegrates into pieces allowing free movement of the stopper head without interference from the solidified steel in the bottom of the receptacle.
  • the coating or shell forming material comprises finely divided refractory material and a binder and is preferably of such consistency that it may be applied with a brush.
  • the refractory material is of such character that it does not sinter at the temperature of the molten metal. Unfired refractory powder is desirably employed.
  • the coating or shell is formed in situ on the stopper head body.
  • the friable refractory material which fragments when subjected to tensile and/or shear stresses may be of various compositions. Examples are magnesia, dolomite, magnesite, mullite, fused or unfused silica, calcined or uncalcined high alumina fire clay, titania, zirconia, zircon, graphite, clay-graphite mixtures, silicon carbide and chromite. Such material is mixed with a binder to form a slurry, mortar, dip coat or wash.
  • the binder may be of various compositions, examples being dextrose, gulac, starch and phosphoric acid.
  • the slurry or mixture of finely divided refractory material and binder is of such consistency that it may be applied with a brush, or it may be applied by spraying or by dipping of the stopper head body into a container of the slurry.
  • the thickness of the coating may be of the order of one-fourth inch, more or less.
  • a coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle comprising a stopper head body with a coating thereon so that when the stopper head is in position closing the nozzle and molten metal is introduced into the relatively cold receptacle metal freezes in the bottom of the receptacle and against the coating of the stopper head, the coating being of friable refractory material which fragments when subjected to tensile and/ or shear stresses so that when the stopper head is subsequently urged upwardly to permit outflow of molten metal through the nozzle the coating fragments, freeing the stopper head, obviating freezing of the stopper head to solidified metal in the bottom of the receptacle.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
  • Furnace Charging Or Discharging (AREA)

Description

United States Patent 3,472,432 COATED STOPPER HEAD FOR CONTROLLING OUTFLOW OF MOLTEN METAL THROUGH THE NOZZLE OF A BOTTOM POUR RECEPTACLE Ronald V. Kilgore, Coraopolis, Pa., assignor to Vesuvius Crucible Company, Swrssvale, Pa., a corporation of Pennsylvania No Drawing. Filed Mar. 28, 1968, Ser. No. 717,033 Int. Cl. B22d 37/00; B65d 47/06; B67d 3/00 US. Cl. 222-541 5 Claims ABSTRACT OF THE DISCLOSURE A coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle comprising a stopper head body with a coating thereon so that when the stopper head is in position closing the nozzle and molten metal is introduced into the relatively cold receptacle metal freezes in the bottom of the receptacle and against the coating of the stopper head, the coating being of friable refractory material which fragments when subjected to tensile and/or shear stresses so that when the stopper head is subsequently urged upwardly to permit outflow of molten metal through the nozzle the coating fragments, freeing the stopper head, obviating freezing of the stopper head to solidified metal in the bottom of the receptacle. The coating preferably comprises finely divided refractory material and a binder and may be of such consistency that it may be applied with a brush. The refractory material of the coating is of such character that it does not sinter at the temperature of the molten metal. An unfired refractory powder is preferably employed. The coating is formed in situ on the stopper head body.
This invention relates to a coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle. While the invention is of wide application it has especial utility in stopper heads for bottom pour receptacles for pouring or teeming molten metal such as bottom pour ladles and tundishes used for pouring or teeming molten steel either into ingot molds or into continuous casting apparatus.
For purposes of explanation and illustration the invention will be described as applied to a stopper head for a bottom pour molten steel ladle or tundish. When molten steel at a temperature of the order of 2900 F. is introduced into a relatively cold receptacle such as a ladle or tundish having a nozzle in its bottom which is initially closed by a stopper head (see, for example, United States Patent No. 3,352,534) the great difference in temperature between the incoming molten steel on the one hand and the receptacle, including the nozzle and stopper head, on the other hand is so great that some of the molten steel freezes in the bottom of the receptacle. This is a phenomenon well known to those skilled in the art which has existed since the inception of the use of bottom pour receptacles for handling molten steel. The solidified or frozen steel in the bottom of the receptacle freezes against the stopper head rendering difiicult or impossible the raising of the stopper head to permit outflow of molten steel through the nozzle in the bottom of the receptacle. The result is damage to the stopper head in any effort to free it from the frozen steel which in turn makes impossible optimum control of outflow of steel from the receptacle and in many cases results in inability to shut off the flow at all once the stopper head is unseated.
Various efforts have been made to solve the problem but prior to my invention none has been fully successful. For example, materials such as sand or lead have 3,472,432 Patented Oct. 14, 1969 been introduced around the stopper head at the upper portion of the nozzle in an attempt to provide a temporary barrier between the stopper head and the initial increment of molten steel entering the receptacle. Such pro cedures are diificult and cumbersome due to the temperature of a preheated receptacle which may be of the order of several hundred degrees Fahrenheit. Moreover they have not satisfactorily prevented the molten steel from freezing against the stopper head, and the introduction of such foreign materials is detrimental to the quality of the steel.
I have solved the problem by providing a coated stopper head comprising a stopper head body with a coating thereon so that when the stopper head is in position closing the nozzle and molten metal is introduced into the relatively cold receptacle the molten metal in the bottom of the receptacle freezes against the coating of the stopper head rather than against the body of the stopper head itself; the coating is of friable refractory material which fragments when subjected to tensile and/ or shear stresses so that when the stopper head is subsequently urged upwardly to permit outflow of molten metal through the nozzle the coating fragments, freeing the stopper head, obviating freezing of the stopper head to solidified metal in the bottom of the receptacle. The coating acts in the nature of a friable shell like an egg shell sothat when the stopper head is raised the shell disintegrates into pieces allowing free movement of the stopper head without interference from the solidified steel in the bottom of the receptacle.
The coating or shell forming material comprises finely divided refractory material and a binder and is preferably of such consistency that it may be applied with a brush. The refractory material is of such character that it does not sinter at the temperature of the molten metal. Unfired refractory powder is desirably employed. The coating or shell is formed in situ on the stopper head body.
The friable refractory material which fragments when subjected to tensile and/or shear stresses may be of various compositions. Examples are magnesia, dolomite, magnesite, mullite, fused or unfused silica, calcined or uncalcined high alumina fire clay, titania, zirconia, zircon, graphite, clay-graphite mixtures, silicon carbide and chromite. Such material is mixed with a binder to form a slurry, mortar, dip coat or wash. The binder may be of various compositions, examples being dextrose, gulac, starch and phosphoric acid. The slurry or mixture of finely divided refractory material and binder is of such consistency that it may be applied with a brush, or it may be applied by spraying or by dipping of the stopper head body into a container of the slurry. The thickness of the coating may be of the order of one-fourth inch, more or less.
When the molten steel is introduced into the receptacle that portion of it which solidifies in the bottom of the receptacle freezes against the coating or shell which 'protects the body of the stopper head from the frozen metal so that the stopper head may be lifted without interference from the frozen metal, the coating or shell fragmenting or disintegrating and passing out through the nozzle with the molten steel and either being consumed or ultimately forming part of the slag which may be separated from the molten steel.
While I have described certain present preferred embodiments of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.
I claim:
1. A coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle comprising a stopper head body with a coating thereon so that when the stopper head is in position closing the nozzle and molten metal is introduced into the relatively cold receptacle metal freezes in the bottom of the receptacle and against the coating of the stopper head, the coating being of friable refractory material which fragments when subjected to tensile and/ or shear stresses so that when the stopper head is subsequently urged upwardly to permit outflow of molten metal through the nozzle the coating fragments, freeing the stopper head, obviating freezing of the stopper head to solidified metal in the bottom of the receptacle.
2. A coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle as claimed in claim 1 in which the coating comprises finely divided refractory material and a binder and is of such consistency that it may be applied with a brush.
3. A coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle as claimed in claim 1 in which the coating comprises refractory material which does not sinter at the temperature of the molten metal.
References Cited UNITED STATES PATENTS 675,372 6/1901 Brooks 22254l X 1,585,002 5/1926 Williams i222559 1,732,282 10/1929 Sage 222541 X 2,066,947 1/1937 Remington et a1. 222541 X 3,124,854 3/1964 Dore 222559 X SAMUEL F. COLEMAN, Primary Examiner US. Cl. X.R. 222559
US717033A 1968-03-28 1968-03-28 Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle Expired - Lifetime US3472432A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US71703368A 1968-03-28 1968-03-28

Publications (1)

Publication Number Publication Date
US3472432A true US3472432A (en) 1969-10-14

Family

ID=24880434

Family Applications (1)

Application Number Title Priority Date Filing Date
US717033A Expired - Lifetime US3472432A (en) 1968-03-28 1968-03-28 Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle

Country Status (3)

Country Link
US (1) US3472432A (en)
DE (1) DE1903337B1 (en)
GB (1) GB1182218A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838798A (en) * 1971-01-21 1974-10-01 Leco Corp Porous tundish nozzle

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2123726A (en) * 1982-07-01 1984-02-08 James Menzies Thornton Ladle etc. stopper

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US675372A (en) * 1900-09-13 1901-06-04 Russia Cement Company Collapsible tube.
US1585002A (en) * 1924-02-19 1926-05-18 Williams Herman Pengelly Pouring device
US1732282A (en) * 1927-07-13 1929-10-22 Sage Herbert Roy Container for liquids
US2066947A (en) * 1935-05-16 1937-01-05 Peerless Tube Company Collapsible tube
US3124854A (en) * 1964-03-17 James

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3124854A (en) * 1964-03-17 James
US675372A (en) * 1900-09-13 1901-06-04 Russia Cement Company Collapsible tube.
US1585002A (en) * 1924-02-19 1926-05-18 Williams Herman Pengelly Pouring device
US1732282A (en) * 1927-07-13 1929-10-22 Sage Herbert Roy Container for liquids
US2066947A (en) * 1935-05-16 1937-01-05 Peerless Tube Company Collapsible tube

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3838798A (en) * 1971-01-21 1974-10-01 Leco Corp Porous tundish nozzle

Also Published As

Publication number Publication date
GB1182218A (en) 1970-02-25
DE1903337B1 (en) 1970-02-19

Similar Documents

Publication Publication Date Title
US3395840A (en) Nozzle for a bottom pour ladle for molten metal
US3465811A (en) Plants for the continuous casting of steel
EP1052233A4 (en) Alumina-magnesia-graphite type refractory
US3230056A (en) Casting steel ingots
US3962492A (en) Method of protecting refractory lining in containers for molten metal
US4623131A (en) Molten metal handling vessels
US3472432A (en) Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle
JPS6099462A (en) Molten metal discharge device
US3196504A (en) Cast nozzle inserts
US4785979A (en) Flow control nozzle for bottom-pour ladles
US4549677A (en) Casting of aluminium-killed steels
US3847312A (en) Molten metal pouring valve having valve actuator extending through inclined channel
US3554489A (en) Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle
US4854550A (en) Stopper for retaining slag and process for implementation and manufacture thereof
US3549124A (en) Coated stopper head for controlling outflow of molten metal through the nozzle of a bottom pour receptacle
US3094424A (en) Sintered refractory material
CA1077674A (en) Method of starting a pour in continuous casting plant and an arrangement for performing the method
US4909484A (en) Prevention of slag buildup in steel ladles
JPH11123509A (en) Immersion nozzle for continuous casting
US4936553A (en) Method for retaining slag during the discharge of molten metal from a vessel
US4900603A (en) Refractory, heat insulating articles
GB1391714A (en) Downward-discharge vessels for molten material
US3354940A (en) Continuous casting apparatus with improved nozzle composition
GB2083896A (en) Refractory blocks for metal pouring vessels
US3477682A (en) Ingot mold with hot top and refractory lining for inducing progressive axial solidification