Water cooled panel

A water cooled panel (1), e.g. for metallurgical use, is constructed from a plurality of rectangular hollow section tube lengths (2), with adjacent tube lengths oriented corner-to-corner in a diamond array, with geometrical diagonals (4) of the tubes in a common plane (5), or generally so, and with means (6, 7, 12) to secure the tubes in such orientation, and with means (14-20) to ensure water flow communication between an end portion of one tube length (2) and an end portion of an adjacent tube length (2).

FIELD OF INVENTION 
This invention relates to a water cooled panel adapted for instance to form 
part of a furnace, typically an electric arc furnace, as part of the 
furnace wall, roof tunnel etc., or to constitute ancillary equipment of 
such a ladle roof. 
DESCRIPTION OF PRIOR ART 
In GB 2198826 is described a panel constructed from a plurality of hollow 
section, water conveying tube lengths of mild steel which are welded 
together to form a panel of required shape and dimensions. Such panels 
have proved in practice to provide exceptional service in terms of freedom 
from maintenance, reliability, and lifespan. 
However, for metallurgical furnace installations, to achieve slag pick-up 
by such panels from the surface of a melt, resulting in advantageous heat 
flux decay due to the presence of the slag, it is usually necessary to 
provide on the "hot" face of the panel a series of so-called slag 
catchers, which are metallic stalks or shelves, adapted to encourage the 
slag pick-up, and to propagate the collection of slag, and whilst such 
slag catchers are operationally satisfactory they are not, unlike the 
remainder of the panel, water-cooled, and consequently at operational 
temperatures of say 230.degree. C., cracks have been known to form in the 
zones where the slag catchers are welded to the "hot" face of the panel. 
Furthermore, prior art panels in accordance with GB 21998826 have a cooling 
effect dependent basically upon the surface area of the panel presented to 
the furnace and the rate of flow of cooling water through the panel, and 
whilst the former factor is of course finite, limitations are also placed 
upon maximum water flow resulting from the water-conveying cross-section 
of the tube lengths as well as pump and reservoir capacities. 
OBJECT OF THE INVENTION 
A basic object of the present invention is to provide an improved panel, 
which in certain operational circumstances, has advantages beyond these 
afforded by GB 2198826. 
SUMMARY OF THE INVENTION 
According to a first aspect of the present invention there is provided a 
panel, adapted, in use, to be water cooled, constructed from a plurality 
of hollow section tube lengths of rectangular cross-section, with adjacent 
tube lengths oriented corner-to-corner in a diamond array, with 
geometrical diagonals across the corners of the tube lengths in a common 
plane, or generally so, and with means to secure the tube lengths in such 
orientation, and with means to ensure water flow communication between an 
end portion of one tube length and an end portion of an adjacent tube 
length. 
Thus, the resulting non-planar "hot" face of the panel, whereby the "hot" 
face of the panel is defined by 45.degree. walls of the tube lengths and 
an interposed 90.degree. corner, results in some walls encouraging (in the 
case of metallurgical use of the panel) slag pick-up, thereby constituting 
slag pick-up areas. However, slag pick-up can be enhanced with the 
attachment of slag catchers. Furthermore, the diamond array of the tube 
lengths of the panel results in a greater surface area being presented to 
e.g. a furnace, for greater cooling effect than is possible with a planar 
panel, all other factors being the same. 
Preferably, the tube lengths are of mild steel, which is preferably hot 
finished. The means to secure the tube lengths in the orientation 
required, is preferably weld metal, although formation of at least a part 
of the panel from copper tube lengths is not precluded. 
In principle, the adjacent, external top and bottom corners of the tube 
lengths may be butted together or may be spaced by a relatively small gap, 
e.g. &lt;20 mm, with weld metal located at the base of the resulting 
"V"-grooves on both sides of the panel, i.e. on the intended "hot" face, 
and on the intended "cold" face of the panel. The weld metal may be 
continuous, or space welding may be effected. 
As an alternative to welding together adjacent tube lengths, the tube 
lengths may be welded to a common, "cold" side, backing plate, 
conveniently by welding "cold" corners to the backing plate, preferably at 
slots cut into the backing plate and serving both for welding and for tube 
length location. Again, adjacent corners of adjacent tube lengths may be 
butted together, or may be spaced by a relatively small gap, e.g. &lt;20 mm. 
For a panel intended to form part of a furnace wall, the tube lengths are 
preferably arranged in a parallel array, either horizontally or 
vertically. The tube lengths may be straight, to produce a flat panel, or 
may be curved, to produce a curved panel, as would be required for a wall 
of a conventionally circular-in-plan electric arc furnace. Thus, if a 
panel subtended an arc of 30.degree., then twelve such panels would be 
required in order to form a complete wall. Furthermore, instead of being 
curved in one plane, the panel may be curved in two planes, as might be 
required if the panel were to form part of a furnace roof. The panels may 
be rectangular, segmental, or circular (flat, convex or frusto-conical) 
depending on their intended installation. 
Preferably, the panel, of whatever configuration, is provided, along one 
side, with a water inlet tube length extending orthogonally or generally 
so, (with respect to the longitudinal axes of the tube lengths of a 
rectangular panel) or radially (in the case of a segmental panel). Thus, 
for a furnace wall panel with horizontal tube lengths, the water inlet 
tube length extends vertically (when the panel is assembled into a 
furnace), with water flow being down the inlet tube length, into the 
lowermost tube length and then in a zig-zag route successfully through the 
stack of tube lengths of the panel, until water exits from an exit 
aperture in the uppermost tube length. 
To provide for inlet and outlet of water from the panel, the uppermost tube 
length (in the case of a panel intended to be used in a vertical plane) or 
the radially outermost tube length (in the case of a segmental panel) is 
divided at approximately its mid-length into two halves, with one half 
provided with a water inlet port and the other half with a water outlet 
port, and with the water inlet half in water flow communication with the 
water inlet tube, and with the outlet half in water flow communication 
with the last of the tube lengths. 
Furthermore, the upper end of a panel intended for use in a vertical plane, 
may be provided with two spaced-apart plates extending the full length of 
the panel, the underside of the upper plate being welded to the top corner 
of the divided tube length and the bottom plate being welded to the cold 
corners of the next tube length down. 
The upper plate may be two lifting holes whereby the panel may be craned in 
and craned out of its required location, whilst the lower plate may be 
provided with locating holes. 
Slag catchers, if provided, may simply take the form of metallic stalks or 
plates, typically of mild steel, and may be located at regularly spaced 
locations along each tube length, and preferably staggered with respect to 
the slag catchers of an adjacent tube length. 
According to a second aspect of the invention there is provided an electric 
arc furnace incorporating as its wall, or part of its wall, and/or its 
roof, or part of its roof, at least one panel in accordance with the first 
aspect. 
According to a third aspect of the invention there is provided a ladle 
incorporating as its roof a panel in accordance with the first aspect.

DETAILED DESCRIPTION OF THE DRAWINGS 
A water cooled panel 1 is constructed from a plurality of parallel tube 
lengths 2 of rectangular hollow section mild steel and thereby having four 
corners 3. Adjacent tube lengths 2 are oriented on their top and bottom 
corner 3, in a diamond array, with geometrical diagonals 4 of the tubes in 
a common plane 5, which, in the case of a furnace panel, is upright. In 
the embodiment of FIG. 1 the corners 3 are butted together and adjacent 
tube lengths 2 are secured by weld metal 6 at a "hot" face of the panel, 
and weld metal 7 at a "cold" face of the panel, resulting in the "hot" 
face of the panel being defined by two 45.degree. walls 8, 9, of the panel 
and an interconnecting "hot" corner 3. The walls 8 encourage slag pick-up 
thereon. For enhanced slag pick-up, a plurality of slag catchers 10 are 
welded to portions of the tube lengths 2 at the "hot" face of the panel. 
Clearly, the panel is constructed to required overall dimensions by 
employing an appropriate number of tube lengths 2 to create a panel of 
required height, with the tube lengths 2 being of length dependent upon 
that required for the panel. 
In the embodiment of FIG. 2, adjacent tube lengths 2 are welded to a 
backing plate 11 which, for the purpose, is provided with a plurality of 
slots 12 which enable a "cold" corner 3 of each tube length 2 to be 
located therein, thereby ensuring correct positioning of the tube lengths 
2 with respect to the backing plate 11, for the tube lengths 2 to be 
secured by weld metal 7. Also in this embodiment, the top and bottom 
corners 3 are not butted together but are located with slight spacing of 
up to 20 mm. Again, slag catchers 10 may be provided on the "hot" face of 
the panel 1. 
The panels 1 are cooled by water flow, e.g. at 100 gallons per minute, 
along the interiors 13 of the tube lengths 2, with the water following a 
zig-zag flow path firstly into and along a lowermost tube length 2 and 
then into the adjacent upper tube length 2 etc., until water exits from 
the uppermost tube length 2 to flow to reservoir etc., and various 
proposals are shown in FIGS. 3a to 6b for achieving water flow 
communication and flow direction reversal between adjacent tube lengths 2. 
In detail, in the panel embodiment of FIGS. 3a and 3b, the tube lengths 2 
are both butted and slightly spaced (as in the FIG. 1 and FIG. 2 
embodiments respectively) and ends 14 of the tube lengths 2 are open and 
angled at 45.degree. so that a generally triangular insert 15 may be 
welded as a mitred fit across the ends to constitute a return chamber 
having an hexagonal end configuration for reversing the direction of water 
flow. FIG. 3a also indicates the staggering of slag catchers 10 between 
adjacent tube lengths 2. 
In the embodiment of FIGS. 4a and 4b, adjacent tube lengths 2 are all 
spaced apart (as in the FIG. 2 embodiment), with the ends of the tube 
lengths 2 open, inset and welded into a box section structure 16 separated 
by plates 17 into individual water return chambers 18 communicating 
between the open ends of adjacent tube lengths. 
In the embodiments of FIGS. 5a and 5b, the tube lengths 2 are butted and 
welded together (as in the embodiment of FIG. 1), and the ends of the tube 
lengths 2 are closed off by a plate 19 forming part of a return chamber 20 
common to adjacent tube lengths 2 and also having an hexagonal end 
configuration. 
In the embodiment of FIGS. 6a and 6b, the tube lengths are again butted and 
welded (as in the FIG. 1 embodiment), and the ends of the tube lengths 2 
are closed off by a plate 21 forming part of similar water return chamber 
20. 
FIGS. 7a to 7c illustrate a curved panel to form part of an electric arc 
furnace, the curvature being apparent from FIG. 7c. The uppermost tube 
length 2 is divided into two halves with the left-hand half constituting 
an inlet tube half and the right-hand half constituting an outlet tube 
half. Thus, to the left-hand side is welded a water inlet port 22, with 
the left-hand side connected to a vertical water inlet tube length 23 
extending to the lowermost tube length 2. The water then flows in a 
zig-zag path from the lowermost tube length 2 and exits into the 
right-hand side of the uppermost tube length 2, leaving the panel via the 
outlet port 24. Also illustrated are lifting legs 25 whereby the panel 1 
may be craned into and out of, e.g. an electric arc furnace, and locations 
holes 26 whereby the panel may be correctly positioned, e.g. with respect 
to other components of an electric arc furnace.