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Патент USA US3463482

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Aug- 25, 1969
Filed April 21. 1967
w vavme
United States Patent 0 ice
Patented Aug. 26, 1969
A further object of the invention is to provide a taphole
conduit for a basic oxygen furnace composed entirely of
pre?red, prefabricated refractory shapes.
Russell A.‘ Buchholz, Pittsburgh, Pa., assignor to Dresser
Industries, Inc., Dallas, Tex., a corporation of Delaware
Filed Apr. 21, 1967, Ser. No. 632,688
Other objects of the invention, will in part, be apparent
Int. Cl. C21b 7/12; C21c 5/50; F27b 7/00
US. Cl. 266-42
5 Claims
of the invention, reference should be had to the following
In order to more fully understand the nature and scope
detailed description and drawings in which:
FIG. 1 is a perspective view, partly broken away, of a
The present disclosure relates to improved taphole con
struction and taphole refractories for metallurgical vessels,
for example, oxygen converter vessels. Particularly, the
invention relates to a taphole fabricated from a plurality
of prefabricated cylindrical conduit segments. Each seg
ment has a substantially uniformly dimensioned molten
metal passage of rectangular cross-sectional configuration,
the longest surfaces of the passage being substantially in
alignment with the vertical axis of the vessel.
basic oxygen furnace, particularly showing the taphole
side of the furnace; and
FIG. 2 is a perspective view of a prefabricated taphole
conduit for use in metallurgical vessels according to the
present invention.
:In accordance with the present invention and in attain
ment of the foregoing objects, there is provided a metal
lurgical vessel of the type having an outer metal support
structure, a refractory lining interior of the support struc
ture, a taphole opening passing through the lining and
support structure and a taphole assembly passing through
the taphole opening. The assembly is composed of a
plurality of prefabricated, ceramically bonded cylindrical
In the processing of molten steel, in furnaces such as
conduit segments. Each segment includes a passage for
the basic open hearth and the basic oxygen furnace, re
molten metal between the end surfaces thereof. Further,
fractories having a high degree of erosion resistance must 25 the opposed ends of the segments are preferably provided
be employed in the metal contact areas. One such area of
with complementary interlocking means, such as tongues
and grooves, for mating with an adjacent segment. The
these vessels, which is vulnerable to erosion is the tap
hole of the vessel. The taphole of a metallurgical furnace
molten metal passage is of substantially uniform dimen
may be disposed in various locations depending on the
sions and is rectangular in cross-sectional con?guration.
furnace type. For example, in the basic open hearth, a 30 The longest surfaces of the con?guration are in align
taphole is located below the molten metal bath, while in
ment with the vertical axis of the vessel. The conduit
segments are arranged in series and are complementarily
the basic oxygen furnace, it is located above the metal
mated. to provide an integral taphole assembly having a
bath and the furnace is tilted to allow gravity ?ow of the
continuous molten metal passage.
molten metal through the taphole.
In the formation of furnace tapholes, by prior practice, 35
a steel pipe, generally ranging from 2 to 6 feet in length
was placed in the taphole area and an unconsolidated re
fractory mix was rammed or cast around the pipe to hold
The taphole conduit segments may be fabricated by
methods well known in the art. One method includes form
ing a stiff, mud-like mixture of selected refractory mate
rial, vibration casting and then burning at a suitable tem
perature to impart maximum strength. However, the most
it in place. After the ?rst tapping of a furnace heat, the
steel pipe would melt out and a completely refractory 40 economical and preferred method of fabrication is by
mixing the selected refractory material with a tempering
taphole would result. However, these tapholes are physi
agent and ramming the mixture in a mold conforming to
cally unsatisfactory for various reasons. The ramming and
the contours of the conduit segments to obtain good
casting mixes had to be, of course, placed in the furnace in
densities upon subsequent burning. In either method, the
an unburned state and thus could not attain the maximum
density'and strength necessary to develop su?icient erosion 45 burning and ceramic bonding may be carried out after the
segments are assembled into an integral unit, if the bum
resistance necessary to satisfactorily survive a furnace
ing kiln can accommodate the complete unit. An advantage
heat. Further, the density and the strength of the tapholes
of ?ring the segments before assembly is that the segments
were non-uniform from end to end._
may be shipped to the job site where they are assembled
It has been suggested to prefabricate a combination of
without great risk of damage.
castable and metal pipe. There has also been some sug
The conduit segments may be composed of any basic
gestion to employ prefabricated refractory sleeves to form
refractory materials characterized by relatively good ero
the tapholes. These sleeves had a circular molten metal
sion resistance in contact with molten steel produced in
passage which was found to be satisfactory for a period
basic steelmaking furnaces. The preferred refractory mate
of time. However, with ‘the rapidity that steel is now be
ing produced especially in basic oxygen furnaces, i.e., 25 55 rials used in the furnaces mentioned are dead burned mag
nesite and dolomite and mixtures thereof. Other basic re
fractory materials having relatively good erosion resist—
greater number of heats. The previously mentioned pre
ance would also be satisfactory. These refractories may be
fabricated tapholes, because of their circular molten metal
tar impregnated and contain various other refractory in
passages were found to erode quite rapidly along the side
wall portion of the passageway with respect to the vertical 60 gredients known in the art to impart superior physical
properties. A particularly useful refractory sleeve is com
axis of the furnace. However, it has been discovered and
posed of extremely refractory dead burned magnesite
it is upon this that the invention is largely predicated that
material of high purity periclase having a magnesia con
taphole life can be increased by providing a molten metal
tent of at least about 90%, by weight.
passageway of rectangular cross-sectional con?guration
wherein the longest surfaces of the rectangular con?gura 65 Referring to FIG. 1, there is shown a basic oxygen
tion are in alignment with the vertical axis of the vessel.
furnace 10, consisting of an outer metal shell 12, a shell
Accordingly, it is an object of the present invention to
protective lining 14 in contact with the inside surface of
provide a means for fabricating a taphole for metallurgical
the shell, and a brick working lining 16. The vessel is
vessels consisting of preformed, pre?red refractory shapes.
constructed of three major zones, the bottom zone 18, the
Another object of the invention is to provide tapholes 70 barrel zone 20 and the cone section zone 22. The bottom
for basic steelmaking furnaces that may be readily re
zone is dish shaped and of upwardly opening concave
placed between furnace heats.
con?guration. The brick 23 in the bottom zone terminate
heats in 24 hours, a taphole is needed that can survive a
at the barrel zone 20 with their face surfaces inclined
from the bottom upwardly to the cone section zone. The
working lining brick 14 in both the barrel and the cone
section zones are disposed so that their face surfaces
are in horizontal plane. The cone section zone, having
a taphole area 26 extends upwardly and terminates in
the form of a mouth 28 at the top of the vessel. The
cone section zone is of downwardly opening truncated
the segments so that the long surfaces thereof become
the side walls of the metal passage, greater life is obtained
with such a taphole than was obtained with previous
taphole con?gurations.
While the invention has been described in the drawings
with reference to basic oxygen steelmaking vessels, it
should not be limited thereto.
Having thus described the invention in detail and with
sui?cient particularity to enable those skilled in the art
Disposed in the taphole area of the vessel is a taphole 10 to practice the invention, what is desired to have covered
cross-sectional con?guration.
by Letters Patent is set forth in the following claims:
assembly 30 according to the present invention, which is
composed of a plurality of identical conduit segments.
An individual conduit segment is shown in FIG. 2.
Each conduit segment 32 contains opposite ends which
I claim:
1. 1n metallurgical vessels of the type having an outer
metal support structure, a refractory lining interiorly
adjacent the support structure and a taphole opening,
are provided with a tongue 34 and a groove 36 for inter
locking and mating with an adjacent segment in molten
a taphole assembly passing through said taphole opening
metal sealed relation. The conduit segments have gen
erally opposed faces 38 and opposed sides 40. The op
posed sides 40 contain a slight projection 42 for reasons
that will be discussed subsequently. The molten metal
composed of a plurality of prefabricated, ceramically
bonded conduit segments having opposite ends, each
segment having a substantially uniformly dimensioned
passage is of rectangular cross'sectional con?guration
having opposed long surfaces 44 and opposed short
?guration, the longest surfaces of said passage being in
molten metal passage of rectangular cross-sectional con
alignment with the vertical axis of the vessel, said conduit
segments being complementarily mated to provide a
surfaces 46.
In practice, the taphole assembly of the prosent in
continuous molten metal passage.
2. The vessel of claim 1 in which the opposite ends
of the conduit segments are provided with interlocking
vention can be placed in a basic oxygen vessel shown
in FIG. 1, readily and with a minimum of labor. Gen
erally, a refractory cement is not necessary at tongue
and groove joints, since at the operating temperatures
of the vessel the conduit segments will expand slightly
means for mating with an adjacent segment.
3. The vessel of claim 2 in which the complementary
interlocking means of the conduit segments consists of
to provide a suf?cient seal. However, refractory cement 30 tongues and grooves.
4. The vessel of claim 1 in which the outer periphery
may be employed, if desired, as an added safety factor
or to facilitate installation.
of the conduit segments is of rectangular cross-sectional
After the brick are stacked up to the cone section zone
and the taphole opening, the ?rst conduit segment is
laid on the refractory lining at the interior of the vessel.
5. The vessel of claim 1 in which the outer periphery
of the conduit segments contain at least one projection
The uppermost brick at the taphole opening are provided
with slight depressions to accommodate the projections 42
extending therefrom for mating with adjacent refractory
lining to hold it in place during installation in the taphole.
on the conduit segments and hold them in place while
the remainder of the segments are being added. Similarly,
References Cited
the lowermost brick extending down from the cone sec 40
tion zone contain depressions for the same purposes.
The remainder of the segments are then added by mating
together the complementary tongues and grooves of a
series of segments and securing them into a unit to pro
vide a continuous molten metal passage.
Each segment is laid so that the longest surface 44
of the metal passage is in substantial alignment with the
vertical axis of the vessel. As was mentioned previously,
it was found that when a heat is tapped, the greatest
Frerichs __________ __ 266—42
Myron __________ __ 6l—11 X
Hansen ________ __ 266—42 X
amount of erosion in a taphole passage occurs at the side 50
walls. It was found that by forming a metal passage in a
rectangular cross-sectional con?guration and arranging
U.S. Cl. X.R.
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