[0001] The invention relates to an iron runner for tapping molten crude iron from a blast
furnace, comprising at least a wear lining which forms a boundary carrying the iron
during operation and a permanent lining in which the wear lining is contained, a steel
or concrete outer boundary and at least an outer lining with a high coefficient of
thermal conductivity which lining is provided between the outer boundary and the permanent
lining.
[0002] Such an iron runner is known from the 'Iron & Steel Engineer' of October 1988, pages
47 - 51. A problem of this known iron runner is the substantial wear which occurs
especially at the level of the iron/slag interface-layer, and which eventually necessitates
repair of the wear lining carrying iron during operation. This is particularly a problem
because this wear is quite substantial in the vicinity of the interface-layer due
to the highly abrasive action of the slag, which when repairing makes it necessary
to pull down a wear lining that is still intact for the greater part.
[0003] The object of the invention is to make the wear of the wear lining proceed more evenly,
which enables the service life of the iron runner to be prolonged and the iron runner
to be operated at lower operational costs.
[0004] To that end the iron runner in accordance with the invention is characterised in
that the outer lining is provided with a thickening in the direction of the wear lining,
which thickening is applied at the level of the interface-layer being present during
operation between the iron being carried through the runner and a slag layer floating
on the iron.
[0005] Surprisingly it has been found that the better cooling of the wear lining obtained
by this, at the level of the iron/slag interface-layer being present during operation,
counteracts the wear of the wear lining there. This effect is highly enhanced by the
embodiment of the iron runner in which the thickening of the outer lining adjoins
directly the permanent lining.
[0006] In the following the invention will be illustrated by reference to the drawing of
a non-limitative example of embodiment of the iron runner in accordance with the invention.
[0007] Fig. 1 shows a cross-section of the iron runner in accordance with the invention.
[0008] In Fig. 1 the iron runner (1) is shown of which the boundary carrying the iron is
formed by a wear lining (2). For the wear lining (2), which may consist of a number
of layers able to move relative to each other, different kinds of material may be
used, but it is normal to use a refractory concrete for this. Directly adjoining the
wear lining (2) a carbon intermediate lining (3) may be used as a permanent lining
for temperature equalisation of the wear lining (2). However, this intermediate lining
(3) is not essential to the invention. Adjoining this intermediate lining (3) and
in the absence thereof, adjoining the wear lining (2), an insulating layer (4) is
provided which consists of a refractory concrete. The outer lining (6, 7) consists
of a bottom plate (6) and side walls (7) which are thermally interconnected.
By using carbon, graphite or semi-graphite, but preferably graphite for the outer
lining (6, 7) the required thermal conductivity is obtained in this place and it is
possible to apply insulating refractory lining layers (8, 9) directly adjoining the
side walls (7).
[0009] In accordance with the invention the thermally high-conducting side walls (7) of
the iron runner (1) are now also provided with a thickening (10) in the direction
of the wear lining (2), which thickening (10) is applied at the level of the interface-layer
being present during operation between the iron (11) being carried and the slag layer
(12) floating on it. Preferably the thickening (10) adjoins directly the wear lining
(2). By this an especially effective local cooling of the wear lining (2) is obtained
at the level of the iron/slag interface-layer, by which the wear of the wear lining
(2) at the level of said interface-layer is counteracted and a longer service life
of the wear lining is achieved.
1. Iron runner for tapping molten crude iron from a blast furnace, comprising at least
a wear lining which forms a boundary carrying the iron during operation and a permanent
lining in which the wear lining is contained, an outer boundary and at least an outer
lining with a high coefficient of thermal conductivity which lining is provided between
the outer boundary and the permanent lining, characterised in that the outer lining
is provided with a thickening in the direction of the wear lining, which thickening
is applied at the level of the interface-layer being present during operation between
the iron being carried through the runner and a slag layer floating on the iron.
2. Iron runner in accordance with claim 1, characterised in that the thickening of the
outer lining adjoins directly the wear lining.
