Note: Descriptions are shown in the official language in which they were submitted.
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The invention relates to metallurgical vessels ofthe type used in continuous casting of steel and known as
tundishes.
British Patent Speci~ication 1,364,655 describes a
tundish having an outer metal casing ~nA a permanent
lining of refractory material ad~acent the casing and
an expendable lining made up of a set of slabs of re-
fractory heat insulating material, the impact area of
the tundish being lined with highly erosion resistant
or sacriiicial materlal, The tundish there disclosed
has a generally flat base lined with refractory bricks
upon which is super$mposed a lining of slabs as de-
fined. Nozzle wells are set into the base and these
are also lined in such a way as to leave the nozzle
ltself open.
Certain tundishes have curved bases and for these
it is not readily possible to use slabs as disclosed
in the ~ritish Speclflcatlon noted unless they are
~ccurately cut to size which is time-consuming and ex-
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pensive. Cur~ed slab~ can be manufactured, albeitwith difflculties. However~ in order to make curved
slabs, curved formers are needed, made to close toler-
ances. In practice, these neYer fit the curve of
the tundish lining exactly, especially once the latter
i~ not new, which can lead to fitting difficulties
and brea~ages. m e present ~n~ention concerns an
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alternati~e and superior way of lining the floor of such
a tundish.
According to the present in~ention there is provi-
ded a tundish comprising an outer metal casing formed
of a base of generally arcuate section and generally
upstanding ~idewalls, the impact area of the tundish
being lined with a highly erosion-resistant or a
sacrificial material, a permanent lining of refractory
material being located ad~acent the sidewalls and the
base of the casing, an inner expendable lining of
refractory heat-insulating material being located
ad~acent the permanent lining, wherein the inner expen-
dable lining is made up of a plurality of elongate
slabs hau~ga ~lexible central portion and two end
portions, ths central portion being deformed to fit
the generally arcuate base and the two end portions
being located ad~acent the tundish sidewalls.
me reguired degree of n exibility of the central
portion Or each slab can be obtained by suitably for-
mulating the composition of which the lining is made,
but this may be un~atisfactory from the point of view
of the performance of the lining material. Flexibi-
lity can be conferred by suitably formulating the
composition used to make the lining to include suitable
organic and/or inorganic fibres, e.g. asbestos, cal-
cium silicate, and alum~nium silicate fi~res, paper
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fibres and wood pulp.
Preferably, however, the central portion of the
slab is made up of a plurality of trans~erse sections
extendlng across the slab and either connected to-
gether by thin webs of the material of the slab so
giving the slab an ability to fold or connected to-
gether by a suitable internal or external reinforce-
ment. A particularly preferred type of slab is one
in which the centrsl area comprises a plural1ty of
transverse slabs of re~ractory heat insulating
material ~oined to each other and to the end portions
of the slab by an internal wire mesh reinforcement.
The use of such slabs to line tundishes is ad-
vantageous as it makes for rapid and easily carried
out lining installation with a minimum of ~oins to
be sealed agalnst metal penetration; the gaps between
the slabs close up when the lining slab i8 put into
position, The ease and speed Or installing the
expendable lining of the lnvention is highly advan-
tageous and leads to substantial steelwork~ economies.
An embodiment oi the invention is illustrated
in the accompanying diagrammatic drawings, in which
Figure 1 is a tran~verse sectional view oi a
tundish incorporating an expendable l~n~ng;
Figure 2 i3 an end ele~ation o~ a llning slab
for use in the tundish o~ F~gure 1, and
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Figure 3 is a sectional view of Figure 1 showing
the slab during its insertion into the tundish.
me tundish shown in the Figures comprises an
outer metal casing 1 comprising integrally formed
opposite sidewall~ 2 Joined by an arcuate base 3.
Reinforci~g flanges 4 are located on the outside of
the casing, together with lifting hooks and like parts,
not shown. The side walls and base of the casing
are lined with a permanent refractory lining 5,
formed of one or more layers of refractory brick or
cast retractory concrete,
An expendable lining comprise~ a row of rela-
tively flexible heat-insulating slabs 6, one of which
is shown in Figure 2. The slab is formed o~ a
composition comprising, parts by weight
silica sand 87.5
paper 3.0
urea formaldehyde resin 2.5
phenol formaldehyde resin 2.0
asbestos fibre 5.0
by making an aqueous slurry of the ingredients and
then dewatering that slurry by pressure or vacuum
ag~inst a perforate former of a suitable shape. In
forming the slab a web 7 of wire mesh is located with-
in the thickness of the slab and grooves 8 are formed
in one face in the longitudinal central area of the
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slab and extending from the face of the slab towards
the mesh. The presence of the groo~es 8 ensures that
the central part of the slab may be ~lexed while the
presence of the mesh tends to prevent such flexure
from rupturing the slab.
The slab 6 is preferably 30 mm thick and its
length will depend on the dimensions of the tundish
into which it is to be fitted. Pre~erably for a
slab ~0 mm thick the grooves 8, which generally will
be of -V- cross-sectional shape, extend into the
thickness to a depth o~ about 14 mm. The slab formed
from the composition specified above will be a rela-
tively high heat-insulating reiractory material having
a relatively low heat capaclty.
In use, a slab 6 i8 taken from the flat condi-
tion shown in Figure 2, folded longitudinally into
generally -U- ehape and is then inserted into the
tundi~h to line the permanent lining 5~ The folded
lining is then urged lnto tight engagement with the
permanent lining 5 and where necessary any gaps are
sealed by a re~ractory mortar, AS the slab bends
to take up its final position, the V-section grooves
close up and accordingly a~ter the slab is installed,
these grooves do not provtde areas of possible metal
penetration. It will be appreciated that some o~
the slab3 6 rill overlio ~ornatlons in the tundigh
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wall~ e.g. nozzles, pouring pad, and apertures may be
made in those slabs for such formations, either during
forming or by cutting out from a formed slab.
The presence of slab 6 enables one to achieve
in relation to tundishes having an arcuate base, the
advantages listed in British Patent Specification
1,364,655 for flat base tundishes~
