Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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EXTERNALLY REPLACEABLE STIRRING PLUG FOR MOLTEN METAL VESSEI.S
Back~round of the Invention
Technical Field:
This invention relates to devices for insufflating gas into
a mass of molten metal wherein the insufflating device is posi-
tioned in the vessel upwardly from the exterior of the bottomor wall of the vessel rather than being positioned downwardly
in the vessel as heretofore customary.
Descri~tion of the Prior Art:
Prior structures have generally employed permeable plugs
or solid plugs and spaced jackets thereabout positioned in
apertured pocket blocks. Frusto-conical apertures in the pocket
blocks received the permeable frusto-conical plugs or solid
~rusto-conical plug and ~acket combinations, all of the prior
art devices being so formed that replacement of the pocket block
and the permeable or solid plug and jacket assemblies were made
~rom the interior oi' the vessel necessitating a lengthy and
complicated procedure.
Typical prior art devices may be seen in U.S. P~atent Nos.
4,396,179 to LaBate, 4,383,520 to LaBate, 4,538,795 to Labate,
4,632,367 to LaBate, 4,687,184 to LaBate, et al. and 4,725,047
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to LaBate.
The present invention comprises an improvement with respect
to the devices disclosed in my above-mentioned U.S. Patents.
The present invention enables the relatively rapid and easy
initial placing of a gas introducing device in a hot metal vessel
from the exterior of the vessel by way of an opening in the bottom
wall of the vessel which eliminates the heretofore believed
necessary tearing out the refractory safety lining and working
lining necessary in molten metal vessels such as ladles, furnaces,
tundishes or the like. The down time of a ladle, furnace or
tundish is thus considerably reduced at a substantial cost savings
as eroded gas introducing devices are readily and quickly replaced
from the exterior of the vessel.
Summarv of the Invention
A device for introducing gas into molten metal having a
re~ractory lining and an apertured block positioned in the lining
in registry with an opening in the bottom wall of the vessel,
the aperture in the block being frusto-conical and arranged to
receive a refractory sleeve and a core having passageways
longitudinally thereof positioned in the sleeve and held in
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intimate contact with the aperture in the block by a refractory
spacer through which a gas introducing passageway extends. A
removable portion o~ the vessel bottom plate permits the initial
insertion of the device upwardly into the frusto-conical passage-
way in the block and when the device is eroded or otherwiseaffects the flow of gas upwardly therethrough, it is easily and
quickly removed downwardly and a replacement assembly moved into
the frusto-conical aperture in the block rendering the hot metal
vessel usable with the assurance that the stirring gas being
introduced into the device reaches the molten metal in desired
quantities at desired locations.
Descri~tion of the Drawin~s
Figure 1 is a vertical section through a portion of a vessel
showing the device for introducing gas into molten metal installed
therein;
Figure 2 is an exploded view showing a portion of a hot
metal vessel having a refractory lining and an apertured block
therein with parts broken away and parts in cross section and
illustrating an externally insertable gas introducing device; and
Figure 3 is a perspective view of a portion of a vessell
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the refractory lining and apertured block therein with parts broken
away and parts in cross section illustrating the device of the
invention in operative position.
Descrition of the Preferred Embodiment
In the form of the invention chosen for illustration herein
the device for introducing gas into molten metal in an improved
manner and wherein the device is readily replaceable by moving
the same through an opening in a bottom wall of the vessel may
be seen in Figures 1 and 3 of the drawings.
By referring to Figure 1, the bottom wall 10 of a vessel,
such as a ladle, furnace, tundish or the like for containing
molten metal, will be seen to be provided with an opening 11 which
is normally closed by a movable support plate 12. The opening
11 is of a size to receive a refractory spacer 13 which is
supported by the support plate 12, the spacer 13 having a central
aperture through which a gas supply pipe 14 extends. The usual
sa~ety lining 15 of a molten metal vessel is apertured to receive
the refractory spacer 13 and a safety plate 16 such as disclosed
in my above-mentioned Patent 4,725,047 is positioned on the safety
lining 15 and apertured to receive the upper portion of the
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refractory spacer 13 which is preferably cross sectionally circular.
The safety plate 15 has an annular upturned flange 17 around a
flat central area which registers with the upper surface of the
refractory spacer 13 and supports a centrally apertured block 18, the
aperture being frusto-conical in shape and cross sectionally circular.
A frusto-conical refractory sleeve 19 also cross sectionally circular
is positioned in and registers with the central aperture in the
block 18 and a frusto-conical refractory plug 20 also cross section-
ally circular is positioned in and registers with the frusto-conical
refractory sleeve 19, the arrangement being such that molten metal
is unable to flow downwardly between the registering surfaces of
the block 18, sleeve 19 and plug 20 of the gas introducing device.
The usual refractory lining Zl is positioned on the safety
lining 15 of the vessel and extends upwardly to a level flush
with the upper surface of the centrally apertured block 18, the
frusto-conical refractory sleeve 19 and the frusto-conical refractory
plug 20.
Still referring to Figure 1, it will be seen that a plurality
o~ relatively small passageways 22 are formed in the refractory
plug 20 and are so positioned as to be able to communicate with the
upper end oi' the gas supply pipe 14 which is engaged in the lower
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end of the frusto-conical plug 20.
By referring to Figure 3 of the drawings, it will be seen
that the upper ends of the small passageways 22 are arranged
in a circular pattern spaced radially from the axis of the cross
sectionally circular plug 20 and that each of the passageways 21
is of a flattened oval shape such that a desirable volume of gas
at a desirable pressure can be introduced upwardly therethrough
and into the molten metal in the vessel in which the device is
installed.
It will occur to those skilled in the art that by forming
other frusto-conical refractory plugs 20 with different sized small
passageways 22 therein, a desired volume of gas may be introduced
into the molten metal from a gas source supplying gas at a fixed
pressure, for example 200 lbs. per square inch, and whereby the
desired discharge rate, for example 100 ft. per minute, may be
obtained and that when the gas pressure supply is higher than
that o~ the i'oregoing example the shaping of the small passageways
21 to form narrower elongated jet-like openings will still main-
tain the desired rate of gas introduction into the molten metal
due to the control provided by the shaped passageways 22. A
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suitable passageway 22 may be for example .026 lOOths of an
inch in length by .26 lOOths of an inch in width. It will
be understood that the pressure of gas supplied in a stirring
operation and the volume are determined by the area and depth
of the mass of molten metal in the vessel so that an adequate
stirring of the molten metal may be achieved.
By referring now to Figure 2 of the drawings, an exploded
perspective view of the device of the invention as installed in
a vessel with parts in cross section may be seen. The bottom
wall 10 of the vessel, the safety lining 15 thereof, the safety
plate 16 and the apertured block 18 being shown assembled and in
registry with the opening 11 in the bottom wall 10 of the vessel.
The movable support plate 12 is shown moved to open position so
that the frusto-conical refractory sleeve 19 may be moved upwardly
through the opening 11 and into registry with the frusto-conical
aperture 18' in the apertured block 18. The exterior surface
of the frusto-conical refractory sleeve 19 is sized to sealingly
engage the frusto-conical aperture 18' in the block 18. The
interior 19' of the frusto-conical refractory sleeve 19 is sized
to sealingly register with the exterior of the frusto-conical
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refractory plug 20 and a cavity 23 is formed inwardly of the
bottom of the plug 20 so that the plurality of small passageways
22 communicate therewith. The cavity 23 is sized to fit over
the upper end of the gas supply pipe 14 which extends upwardly
through the centrally apertured refractory spacer 13 as herein-
before described.
It will thus be seen that an externally replaceable stirring
plug for molten metal vessels has been disclosed and that the
arrangement and formation of the several parts, specifically
the frusto-conical refractory sleeve 19 and the frusto-conical
refractory plug 20 which are subject to erosion in the hot metal
bath in the vessel may be quickly and easily replaced by moving
the gas supply pipe 14 and support plate 12 to free the refrac-
tory spacer 13 and permit the refractory core 20 and refractory
core sleeve to be removed downwardly and out of the aperture 18'
ln the apertured block 18 whereupon a replacement sleeve and
plug may be moved upwardly into registry with the aperture 18'
by the spacer 13 and the movable support plate 12 repositioned in
normally closed relation with respect to the openingll and the
gas pipe 14 repositioned, the several operations being completely
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conducted from the exterior of the vessel.
It will occur to those skilled in the art that if desired
small amounts of refractory cement may be used to insure the
sealing of the several parts to prevent the flow of molten metal
therebetween, particularly when erosion has taken place in the
upper portions of the apertured block 18.
It will be recognized that the principal advantage of the
disclosed invention lies in the interchangeability of the
respective parts resulting in a simple, efficient, readily
installed and removed device for introducing gas into molten
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metal for stirring purposes and the like and having thus described
my invention, what I claim is:
_g_
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