Note: Descriptions are shown in the official language in which they were submitted.
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~XPANDABLE, CONSUMABLE STOPP~R PLUG FOR ST~EL.
~AKING AND HANDLING VESS~LS
Background of the Invention
(1) Field of the Inventi.on:
This invention relates to p-lugs for sealing the flow of metal
from molten metal receptacles such as steel making -furnaces,
ladles, and the like.
(2) Description o:f the Prior Art:
Prior art devices oI this type have relied on a number of
different plugs or stoppers. See for example U.S. Patents
3,540,627, 4,010,936 and 4,030,709.
In Patent 3,540,627, a conical metal plug is attached to the
end of a supporting rod and has a conical pad positioned there-
over, the conical pad being formed of a layer of refractory fibers,
such as alumina silica fibers, and a layer of glass fibers, the
metal plug and its conical pad being insertable in the passageway
defined by a tap hole in a molten metal receptacle.
Patent 4,010,936 discloses a stopper plug in a shape corres-
ponding exactly to the shape of the tap hole and formed of non-
porous refractory material, organic fibrous substance, andinorganic fibrous substance together with a.combustible substance,
the material forming a porous molding which is elastic and capable
of shrinking and deformation so that it will remain in the tap
hole of the vessel under nominal pressure of the molten metal
and will deform and be extruded from the tap hole by the increas-
ing pressure of the molten metal when the vessel is tilted.
Patent 4,030,709 discloses the use of a ceramic plug in the
2~ shape of a hollow cone over a solid backing plug which is main-
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taine~ in place un-til the mo]ten me-tal solidi:Eies against the
plug to seal oE-~ the tap hole.
The present invention discloses a novel, expandable, hollow
cone-shaped stopper plug and a wedge-shaped member movab~e therein
to expand the same in the tap hole of a molten m~tal receptacle
so as to ef:Eectively seal -the tap hole for a predetermined -time.
Summary of the Invention
~ n expandable, consumab]e stopper plug for steel making and
handling vessels wherein a blunt nosed hollow refrac-tory plug
is formed o~ fibrous refractory materials, clay-like refractory
materials, consumable materials and a suitable binder -to form an
expandable, stretchable and deformable plug having means for
expanding and deforming the same movably arranged therein.
Description of the Drawings
Figure 1 is a cross sectional side elevation of the stopper
plug;
Figure 2 is an exploded side elevation wi-th parts in cross
section and parts broken away showing the stopper plug and a
tool for expanding the same;
Figure 3 is a cross sectional side elevation of the e~pandable
stopper plug and the tool for expanding the same wi-th broken
lines showing the plug and tool in non~expanded relation and
solid lines showing the plug and tool in expanded relation; and
Figure ~ is a section through a wall of a molten metal
receptacle and a -tap hole therein showing the stopper plug
therein.
Description of the Pre~erred Embodiment
28 Referring to Figure 4 of the drawings, a portion of a
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molten melal receptacle 10 may be seen having a tapping block
11 therein definillg a cylindrical oriEice 12 ~n expandable
consumable stopper plug 13 is shown ln expan~ed position ln tl~e
cy].indrical oririce 12.
The stopper plug may be seen in Figure 1 o~ the draw-lngs to
comprise a blunt nosed, hollow, conical body member 13, -tl~e nose
portion 1~ Or whicll is relatlvely thicker than the wall portions
extending -therefrom. ~ steel cap insert 15 is posi-tioned in
the cavity 1.6 d~fined by the hollow body memben~l3.and immediately
inwardly of and in con~act wi-th the material of the.-blunt nose
porti.on 14 of the s-topper~plug. ~ round tapered member 17
havillg a central aperture 18 therethrough is positioned inwardly
of tlle open end of the hollow body member of the s-topper plug
and is movable into the cavity 16 t~oward the steel cap 15 so
as to e~palld and eplarge the hollow body member 13 deforming the
wall porti.ons thereo~ in an action which will securely position
-the stopper plug in the cylindrica.l oriLice 12 in -the molten
metal receptacle 10 hereinbe:~ore described.
In order that the hollow body member ~3 iorming the stopper
plug may be qulckly and e-fliciently expanded in sealing relation
to a tap hole or the like, an applicator rod 19 is provided as
best seen in Figures 2 and 3 of the drawings, the applicator
rod t9 having a metal. disc ~0 transversely positionecl thereon
inwardly of an encl 21 o~ the rod 19, the other end oi the rod
19 being preerably provided with a suitable hanclle coniiguration 22.
The len~th of the rod 19 between the meta]. disc 20 ancl
the end 21 is predetermined so that upon the end 21 of the rod 19
being posj.tioned through the central oriiic 13 in the round
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tapered member 17 and moved toward the s-teel cap lS, the metal
disc 20 will engage the round tapered member 17 and move i-t
inwardly of the hollow body rnember 13 to the posi-tlon shown ln
solid lines in Figure 3 of the drawings so as to dls-tort and
expand the hollow body member 13 until the end 21 of the appli-
ca-tor rod 19 reaches -the steel cap 15 whereupon any further
movement impar-te~ the applicator rod 19 will distor-t the
material of the blunt nose 14 of the hollow body member 13
and limit the movement of the round tapered member 17 and the
10 expansion and distortion of the hollow ~ody member 13.
It will thus be seen that -the expandable, consumable stopper
plug is moved into the tap hole and distorted and expanded by the
wedging action imparted to the hollow body membe* of the plug by
the round tapered member 17 as it is moved by the applicator rod
19 which is then removed.
In order that the hollow body member 13 of the stopper
plug will retain its desirable consistency and hot metal
stopping properties ~or a predetermined period of time, it
is preferably formed of material comprising a mixture of
2~ fibrous refractory material such as FIBERFRAX*as described
in U.S. Patent No. 3,124,854, or CERAFELT ~,k a product of
Johns-Manville,Company, in a range of approximately 8% by
weight to approximately 25% by weight. These are alumina-
silica ~ibers, dolomite in a range of approximately 32%
to approximately 64% by weight, sodium silicate in a range
of approximately 8~o by weight to 16% by weight, and sawdust
in a range o~ approximately 18% by weight to 27% by weight.
28 The material ~rom which the stopper plug is :Eormed is
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com~letely mixed to a uniform consistency which is essential
in the expanding and distortion of the material when the
plug is inserted in -the tap hole and expanded as herein-
before described.
In addition to the materials above mentioned, rnineral
wool, such as blast furnace slag fibers may be incorporated
and silica, quartz, magnesia, olivine, mullite, aluminum
oxide, chamo-tte, magnesite or perlite may be incorporated with
the dolomite or in place of the same. Resin binders, such
as phenol-formaldehyde resins,urea-formaldehyde resins, and
furan resins may be used in place of the sodium silicate, all
in substantially the same proportions. Other combustible
substances such as paper pulp and wood flour may be used in
addition to the sawdust and/or in place of same, again in
substantially the same proportions. It is essential that the
proportions of the dolomite or its alternate substances be
sufficlent in any of the mixtures to insure the desirable
consistency of the material from which the hollow body
member 13 of the stopper plug is formed so as to enable it to
be deformed and expanded as hereinbefore described.
It will be recogized that the proportions of combustible
and/or disintegrable materials are such that the life of the
stopper plug when subjected to molten metal can be readily
predetermined. The consistency and/or density of the material
also comprises a factor in determining the life expentancy
of the plug when subjected to molten metal.
As disclosed herein the stopper plug is formed of the
28 hereinbefore disclosed materials so as to have a predetermined
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li~e whereupon the co~sumable and/or disintegrable or combustible
materials incorporated therein will react and/or oxidize -to
weaken or change including disintegration of the material o-f
the plug so as to open the tap hole which has been sealed
thereby.
It will occur to those skilled in the ar-t that tap holes
in molten metal receptacles become enlarged by beingworn
away to irregular configurations by molten metal flowing
therethrough. The expandible consumable stopper plug disclosed
herein easily accommodates such irregular shaped tap holes
as the construction, materials and arrangement of the walls
and nose of the plug body distort and expand outwardly as a
result of forward pressure applied to the plug in the tap
hole as hereinbefore described. The expansion and distortion
of the plug thus fills any cavity limited only by the initial
diameter measure of the plug itself with the filled tap hole
remaining filled for the desired predetermined time whereupon
the consumable and/or disintegrable characteristics of the
material of the plug act to open the tap hole.
In a typical metal receptacle the tap hole will be found
to Yary from two to four inches in its initial diameter and
the self-expanding consumable stopper plug of this invention
is acco~dingly preferably formed so tha-t the blunt nose is
approximately three inches in diameter,the opposite
open end of the conical body member thereof
being from eight to ten inches in diameter and the walls
of the conical body member being approximately two inches
2~ thick and the overall length of the expandable, consumable
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stopper plug being between twenty five and thirty inches.
Those skilled in the art wiil recognize that these
dimensions may be very considerable withou-t affecting the
utility, time factor and deformable expandable properties of
the stopper plug.
A typical and satisfactory analysis O:e the refractory materials
of which the stopper plug is formed may comprise silican
dioxide in an amount between 31% and 36% by weight, calcium
dioxide in an amount between 21% and 26% by weight, aluminum
1~) oxide in an amount be-tween 11~ and 15C,' by weight, magnesium
oxide in an amount between 3% and 6% by weight with the amounts
of the several ingredients being sufficient to provide for an
ignition loss of from 25% to 28% and wherein the density,
pounds per cubic inch, is between .0075 lbs. and .0105 lbs.
Having thus described my invention what I claim is:
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