METHOD AND APPARATUS FOR POURING MOLTEN METAL IN A NEUTRAL ATMOSPHERE

METHODE ET DISPOSITIF DE COULEE DU METAL SOUS ATMOSPHERE INERTE

English Abstract

ABSTRACT OF THE DISCLOSURE
A molten metal receiving vessel having substantially
vertically standing walls is provided with a closure
closing said vessel to the atmosphere and directing molten
metal into said closed vessel; the closure includes a hori-
zontally disposed member formed of a low thermal conductivity
refractory material having an opening therein, the opening
being positioned for registry with a nozzle of a ladle, a
heat resistant air lock gasket engages the closure around
the opening and the nozzle, the closure being movable from
a first position on a lip portion of the vessel to a second
position in the vessel engaging molten metal therein and
arranged to float on the molten metal when the level of the
molten metal falls below said second position.
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Claims

The embodiments of the present invention in which an
exclusive property or privilege is claimed are defined as follows:
1. The combination of a molten metal receiving vessel
having substantially vertically standing walls and means for
closing said vessel to the atmosphere and directing molten
metal into said closed vessel; said means including a horiz-
ontally disposed closure formed of a low thermal conductivity
refractory material having an opening therein, said opening
positioned for registry with a nozzle of a ladle, heat
resistant air lock gasket means engaging said closure around
said opening and said nozzle, said closure being movable
from a first position on a lip portion of said vessel to a
second position in said vessel engaging molten metal therein
and arranged to float on said molten metal when the level of
said molten metal falls below said second position.
2. The combination of claim 1 wherein said horizontally
disposed closure is a sheet-like shape larger than and
corresponding to the shape of the vessel and overlying the same.
3. The combination of claim 2 wherein the sheet-like
shape of the horizontally disposed closure has score lines
in its lower surface defining an area smaller than the interior
of said vessel and wherein the edge portions of the sheet-like
shape beyond the score lines are bendable upward in hinged
relation to said sheet-like shape when said closure moves into
said second position.
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4. The combination of claim 1 wherein a heat resistant
sleeve is positioned in said opening in said closure for
registry with said nozzle of said ladle and said air lock
gasket means also engages said sleeve.
5. The combination of claim 4 and wherein a flanged
circular band is positioned on said sleeve inwardly of the
ends thereof with said flange resting on said closure around
said opening therein so as to support said sleeve thereon and
close the opening thereabout.
6. The combination of claim 5 wherein said band has
spaced upper and lower annular flanges thereon, said upper
flange resting on said closure and closing said opening and
said lower flange engaging the lower surface of said closure
and forming a secondary closure for said opening.
7. The combination of claim 1 and wherein the material of
which said closure is formed comprises inorganic fibrous material,
particulate refractory material and a binder.
8. The combination of claim 1 and wherein the inorganic
fibrous material is selected from the group consisting of
asbestos, calcium silicate fiber, aluminosilicate fiber and
alumina fiber.
9. The combination of claim 1 and wherein the material
of which said sleeve is formed is ceramic.
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10. The combination of claim 7 wherein the binder is
an organic binder selected from the group consisting of
synthetic resins, natural resins and carbohydrates.
11. The combination of claim 1 and wherein said closure
also contains an exothermic component.
12. A closure for a tundish of a continuous caster and
the like, said closure comprising a heat resistant fiber board
having an opening therein, said closure being movable from a
first position on said tundish to a second position in said
tundish engaging said hot metal therein and arranged to float
on said hot metal when the level of said hot metal falls below
said second position, heat resistant air lock gasket means on
said closure around said opening positioned to receive the
nozzle of a hot metal ladle in sealing relation and means in
said closure for introducing argon gas and the like into said
tundish and for feeding lead wire and the like into said tundish
simultaneously with hot metal directed through said opening
from the nozzle of said ladle.

13. The method of pouring molten steel into a tundish
on a continuous caster in an oxygen free atmosphere comprising
the steps of sequentially; placing a flat closure on said
tundish in air sealing relation thereto; placing a known
quantity of hexamethylene in said tundish; engaging the nozzle
of a ladle in sealing relation to said opening; pouring molten
steel through the nozzle of the ladle through said opening
and into said tundish so as to vaporize said hexamethylene to
fill said tundish so as to vaporize said hexamethylene to fill
said tundish and expel atmospheric air therefrom; pouring
molten steel through said nozzle and opening to fill said
tundish with said molten steel to a level adjacent said closure;
moving said closure into said tundish to rest on said molten
steel.
14. The method of claim 13 wherein a portion of said
closure is moved away from said tundish sufficiently to permit
a hot topping compound to be placed on said molten steel when
said molten steel in said tundish reaches said level adjacent
said closure and replacing said portion of said closure
on said tundish.
16

15. The method of pouring molten steel into an ingot
mold in an oxygen free atmosphere comprising the steps of
sequentially; placing a flat closure on said ingot mold
in air sealing relation thereto; said closure having an open-
ing therein; placing a known quantity of hexamethylene in said
ingot mold; engaging the nozzle of a ladle in sealing relation
in said opening; pouring molten steel through the nozzle of
the ladle through said opening and into said ingot mold so as
to vaporize said hexamethylene to fill said ingot mold and expel
atmosphereic air therefrom; pouring molten steel through said
nozzle and opening to fill said ingot mold with said molten
steel to a level adjacent said closure; moving said closure
into said ingot mold rest on said molten steel.
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Description

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~IETIIOD AND ~PPA~'l`US FOR POURING MOLTEN MET~L
IN ~ N~UTR~L ~TMOSPIIER~
Background o r the Irrvention
Technical Field:
This invention relates to a method and apparatus for pour:ing
molten metal into a receiving vessel while excluding atmospheric
air there-from.
~escrLptlon of the PrLor Art:
No prior art tnethods or devices are known whereby a relative~y
simple and inexperlsi.ve closure with or without a pouring sleeve
posi-tioned there-through enable a receiving vessel to be charged
with an inert gas and structurally preven-t the entrance of
atmospheric air thereinto.
Summary of the Inven-tion
~ metlhod and apparatus :Eor pouring molten metal in a
neutral atmosphere are disclosed wherein sl.mpLe and :relat-.Lvely
inexpensLve apparatus placed on a receiving vessel :eo:rms a
closed passageway from a ladle,converter or simiLar source of
molten metal to the receiving vessel and is moved to a position
on the molten metal in the receiving vessel when -the same is
filled to main-tain the closure with respect to.the atmosphere

~LZ297~;
while the mol-ten me-tal is discharged :Erom the receiving vessel.
~ powdered hot top compound may be and preferably is
applied to the surface o-E the mol-ten metal to insure sealing
of the same wi-th respec-t to -the atmosphere and -the movable
closure and closed passageway.
Description of the Drawings
Figure 1 is a fragmentary vertical section through a
portiorl of an ingot mold and illustra-ting -the a-tmosphere
excludlng apparatus in a firs-t position;
Figure 2 is a ver-tical sectional view similar to Figure 1
showing the atmospheric excluding apparatus in a second
position in an ingot mold;
Figure 3 is a top plan view o~ the apparatus seen in
Fi.gure 1~
L5 Figure 4 i.s a perspec-tive view showing the apparatus of
Figures ~L and 3;
Figure 5 is a fragmentary vertical section through a
por-tion of an ingot mold and a modified atmospher;.c excluding
apparatus in a first position thereon;
Figure 6 is a vertical sectional view similar -to Figure 5
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~LZX9'7 3L~i
showing -the atmospheric excluding apparatus in a second
position in the ingot mold; and
~ igure 7 is a perspective view on an enlarged scale showing
a ceramic sleeve which is also seen in ~igures 5 and 6 of -the
drawings.
Description oi the Preeerred Embodimen-t
By re:Eerring to the drawings and Figure 1 in parti.cular
a :Eragmetltary view o:E -the upper por-tion oE a receivin~ vessel
10 which may be an ingo-t mold or a -trumpet -Cunnel O-e a bottom
poured ingot mold or a tundish box -Eor a continuous caster
will be seen -to be substantially filled wi-th molten metal
M which has been introduced in-to -the receiving vessel 10 ~rom
a ladle 11 or o-ther source o:E molten metal. The molten metal
M is introduced in-to the rece:Lving vesse] 10 through an opening
12 located in a closure 13 positioned on the open upper end
o:E the receiving vessel 10. The closure 13 may be a sheet-
like sec-tion o~ insu:Lating fiber board or the like. The opening
12 in the closure 13 is fo:rmed subs-tantially centrally -thereoE
as may be seen by reEerring to Figu:re 4 o-E the drawings.
Mol.ten metal is introduced into the opening 12 of the closure

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13 from the ladle or other source Oe mo:Lten meta]. by way o:E a
-tubu].c~r nozzle 1~ the lower end po:r-tion Oe which is providecl
with an air lock gaske-t 15 Iormed Oe suitable refractory fiber
materials and the like which is of an overall tapered shape
and thereby capable of registering in the opening 12 in the
closure 13 and -forming an airtigh-t closure.
A pair O e pipes 16 and 17 may be positioned through the
horizontal wal.l of -the closu:re 13 the pipe 16 being connected
by a Ilexible hose 18 wi-th a source of inert gas such as argon
and the pi.pe 17 provides a sui-table lead-in for an alloy wire
19 which can be introduced into -the molten me-tal therethrough
as desired.
Still referring to Figure 1 of the drawings, i-t will be
seen -that the :Lower sur-face of -the closure 13 Oe insula-tillg
fiber board or the like is provided with fold or score
lines 20 defin:Lng a rectangular o:r o-ther shape sLightly smaller
than the inner rectangular or other shape oe the rec.eiving
vessel 1() and by :reeerring to Fi.gure 3 of -the drawings, a
top plan view of -the appara-tus enabling the pouring of molten
metal in a neutral atmosphere will be seen to include broken

~Z~7~S
e representatiorls Oe the eolcl lines or score l:ines 20
together with diagonal extensions thereof at -the -four corners
of -the closure 13 and connecting with -the cu-t ou-t corners
thereof as indicated by the numerals 21.
At such time as the receiving vessel 10 is filled to a
desired level and the inert gas flow con-tinues, an ed~e por-tion
22 oE ~he c].osure 13 and/or -the ladle 11 and nozzle 1~ is lifted
atld a covering coa-ting o~ powdered ho-t -top compound 23, as
knowrl in the art, is applied to the surface of the mol-ten metal.
10. The horizon-tal sheet-like sec-tion o-f -the cl.osure 13 of insulating
:Eiber board or -the like is -then pushed downwardly so as to bend
the longi-tudinal edge portions 22 thereof in angular relation
-there-to and form four angularly disposed edge sections resembl.ing
wipers, each attached to the sheet-l.ike closure 13 o~ insulating
~5 eiber board or the like and each continuously engaging the
inner walls oe the receiving vessel 10 so as to :eorm an
a:irtight closure.
,Vhen -the horizon-tal sectlon of the closure 1~ is pushed
downwardly to contact either the mol-ten metal M or the
powdered hot top compound floating thereon, a secondary closure,

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no-t shown, may be placed in the opening 1" to ef-fectively seal
the sur-face o:f the molten metal in the vessel 15. At the same
-time the pipes 16 and 17 may be disconnected -from -their respec-
tive sources of gas or metal antl/or removed comp]etely and as
the molten metal ~ in the receiving vessel 10 is fed -therefrom,
as :Eor example into a con-tinuous caster, the entire sealing
apparatus descencls w~th the level o:E the molten metal M and
maintains the atmospheric seal.
In orde:r -to insure the existence of a desirabJe neutral
atmosphere in the receiving vessel. 10 when the first mol-ten
me-tal is poured therein, a smal] quantity of hexamethylene,
also known as cyclohexane, or any o-ther similar readily
vaporizab:l.e liquid having sim-ilar properties is introduced
:Lnto the receiving vessel 10 Wtlell the closure apparatus is first
instal].ed so that the introduction Oe the f-irst molten metal
into the receiving vessel will immediatel.y vapo-rlze the same
and create a suitable gaseous environment that will expel all
of the usual atmosphereic air from -the recei.ving vessel 10
and thus prevent contamination by the reoxiclation of the
molten metal and the undesirable products -thereof.
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?~lodifications in the apparatus ~or pouring molten me-tal
in a neutra~ atmosphlsre will occur to those skilled in the art
and one such modi:eication may comprise -the addition oE exothermic
material as known.in the art into the closure 13 o-E insu]ating
~iber board or the like and/or a-ttaching sections of exothermic
materlal 23A to the lower sur-faces o:f the closure 13 oE insulating
E:Lt)t?r board or the l:lke so that the reac-tion o-E the exothermic
material will add additional heat to the metal in the receiving
vessel and avoid -the usual piping probl.ems -that occur, :Eor
examp~e when mol.ten metal soldiEies in an ingo-t mold or
the like.
Another modi-Eica-tion comprises the use O e a ceramic sleeve
2~L positioned in the opening 12 o:f the closure 13 as seen
in Figures 5,6 and 7 oE the drawings. By re:Eerring thereto
i.t will be seen that this modi:Eication uses an annula:r meta~
band 25 having ver-tically spaced hori~ontally extending annular
Elanges 26 at-tached to the ceramic sl.eeve 24 by suitable
Easteners and receiving -the edges o:E the closure 13 de-Eining
the opening 12 therein. If desired, the closure 13 may be Eormed
in two pieces abutting one another as shown by a broken line 27
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in Flgure ~ oE tlle drawings, -to simplify the placement of -the
annular band 25, the :Elanges 26, and the ceramic sleeve 2~ in
the opening 12 of the closure 13. In this modification, the
pipes 16 and 17 he.rei.nbefore described may be relocated in
the ceramic sleeve 24 as seen in Figures 5 and 6.
It will be unders-tood by those skilled in the ar-t tha-t
the ccramic sleeve 2~ Oe the modi:elcation is Iormed of
re:L'ractory materials that readily withs-tand the -tempe:rature
of mol-ten metal and that -the closure 13 is formed Oe refrac-tory
fibers such as aluminum silica-te in a mixture which may include
dolomite, sodium silica-te, pink clay, mineral wool, e-tc. and
a suitable binder material such as a phenol formaldehyde resin.
The closure :13 may be provided with a transverse fold line
so that il; may be Eolded for Shippitlg . See F in Fi.gure 3.
The appa:ratlls disclosed herein makes possible a method o:E
pouring steel o:r other metal in a receivitlg vesse.l such as
an ingot mold, trumpe-t iunnel mold for bottom poured ingots
or tundish boxes for continuous cast,ers without subjecting
the molten me-tal to the normal a-tmosphere and thereby reduces
or eliminates the possibility of products of reoxidation -Eorm-
ing in the molten metal as would otherwise occur. The method
comprises the introduction into the receiving vessel of a known
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3L~2~37~
quantity of hexamethylene capable of formlng a gaseous cloud
upon subjection to mol-ten metal ini-tially contacting the same
and acting to purge the normal atmosphere from the receiving
vessel,providing a closure of insulating fiber board or the like
with an opening therethrough which may have a ceramic sleeve in
the opening in the closure and positioning the closure with or
without the ceramic sleeve on the -top o:E the receiving vessel,
sealing the edges of -the closure to the upper surfaces of the
receiving vessel, bringing an outlet port nozzle o-f a ladle
or -the like source of molten metal into engagement wi-th the
opening in the closure or against the upper end of -the ceramic
sleeve, d:Lrecting molten me-tal through said opening or the
ceramic s:Leeve into said receiving vessel to a desired height
therein, addillg a topping of powdered hot top compound, such
as acid t:rea-ted graphite or a similar mate:rial. to the sur:eace
of the molten metal and moving the closure with o.r without the
ceramic sleeve downwardly onto the surface of the molten me-tal
and the hot topping compound thereon and permitting said closure
to move downwardly in the receiving vessel with -the molten metal
when the same is withdrawn therefrom so as to maintain a continuous
seal with the receiving vessel and prevent the in-troduction of
atmospheric air into the receiving vessel and its con-tact with
-the mol-ten me-tal therein.

~z9~s
The horizontally disposecl hea-t resis-tant closure 13 is
preferably -Eorme~ oE low -thermal conductivity re:fractory material
such as inorg~nic fibrous ma-terial, particula-te material and an
organic binder; the inorganic fibrous ma-te:rial being selec-ted
-Erom the group consisting of asbes-tos, calcium silica-te
fiber,aluminosilicate fiber and alumina fiber; the particulate
refractory material belng selectecl from a group consis-ting o:f
.sllicia, alumina, ~ircon, olivine, magnesia, aluminosilicates
and carbonaceous materials; and the organic binder being
selected from -the group consisting o~ syn-thetic resins, natural
resins and carbohydra-tes.
It will thus be seen that a method and appara-tus for
pouring mol-ten metal into an ingo-t mold or a -tundish box or a
continuous caster has been disclosed which is relatively
simple to perform with the use of a relatively inexpens:Lve
apparatus and i.t will be observed that -the apparatus is
formod o~ mater:lals including inorganic :Eibrous materLa:L,
particuLate refractory material and ceramic material which may
be easily discarded and replaced wherl e:roded by contact with
the mol-ten me-tal protec-ted -thereby.
Having -thus described my invention, what I claim is:
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