WATERBOX FOR USE WITH A CONTINUOUS CASTING ASSEMBLY FOR VERTICALLY CASTING METAL SLABS

SCOPE OF THE INVENTION

The present invention relates to a waterbox assembly for use in cooling a continuously cast slab, and more particularly a waterbox assembly having a seal member adapted to provide general fluid sealing contact with a vertically cast slab, and which is provided for simplified removal and replacement in the event of wear or with a change in the slab profile.

BACKGROUND OF THE INVENTION

Various production systems are known for continuously vertically casting metal slabs or billets. In a conventional casting plant, a furnace is used to melt and supply molten metal to a tundish. The tundish in turn feeds the molten metal into a mould cavity which is provided with a bottom discharge outlet opening. The outlet opening is chosen with a profile which corresponds to that of the desired cast slab or billet cross-sectional shape, and through which the newly formed slab emerges. A series of pinch rolls positioned below the mould cavity outlet opening grip and draw the emerging slab downwardly from the mould in a substantially continuous manner.

To speed slab production and minimize slab damage by the pinch rolls, cooling apparatus are positioned to cool the slab immediately as it emerges from the mould outlet opening. Conventional cooling apparatus include spray assemblies which are operable to emit streams or sprays of water or other fluids onto the slab surfaces, to assist in the slab cooling and solidification.

It has been proposed to cool the formed slab by drawing the slab through a waterbox or cooling bath prior to its movement between the pinch rolls. Conventional waterboxes are constructed as an open square or rectangular box, and have a size selected to retain the desired volume of cooling fluid therein. In the case of vertical casting plants, a bottom

opening is formed through the bottom of the box through which the cast slab is drawn. To maintain the desired level of cooling fluid, a rubber wiper or sealing member is secured about the bottom opening. Typically, each wiper consists of a .5 to 2 cm thick piece of rubber which is formed having a central opening which has a profile corresponding to the cross- sectional profile of the cast slab. The wiper is typically bolted in place to the bottom of the waterbox by a series of threaded fasteners. The wiper has an edge profile selected to maintain substantial fluid sealing contact with the slab as it moves through the waterbox and downwardly through the bottom opening, so as to minimize water leakage therepast.

As the cast slab is drawn downwardly through the waterbox and outwardly from the bottom opening, water or other suitable cooling fluid is supplied to the box interior to assist in the cooling, solidification and/or hardening of the slab prior to its movement through the pinch rolls.

Conventional waterboxes suffer a disadvantage in that because of fπctional contact between the wiper and the heated slab, the wiper is subject to wear. Overtime, this results in a loss of sealing effectiveness, and ultimately water leakage which may otherwise result in pinch roll lubrication. Heretofore to change either a worn wiper, or to substitute a different wiper having a different edge profile with any change in slab size and/or profile, it has been necessary to shut down the casting plant, and thereafter disassemble and rebuild the waterbox with a new wiper having the desired differing edge profile.

Conventional waterboxes suffer a further disadvantage in that they are poorly suited to ensure the equal cooling across each longitudinal side of the cast slab. The applicant has appreciated that with selected alloys, an increased flow rate of cooling fluid on one longitudinal side of a slab relative to the other, may result in the uneven cooling of the slab surfaces. If this occurs, the more rapidly cooled side of the slab has the potential to contract at a greater rate compared to the warmer side. This in turn may result in either slab bending or deflection as it moves from the waterbox.

SUMMARY OF THE INVENTION

To at least partially overcome some of the difficulties associated with prior art casting assemblies, the present invention provides for a waterbox assembly for use in cooling a cast slab and which permits simplified removal and replacement of worn wiper or seal members, which cooperate with the cast slab to provide a generally fluid-tight seal therebetween. The waterbox assembly is sized to retain a selected volume of cooling fluid therein as a cooling bath to assist in the cooling and solidification of the slab surfaces as it moves therethrough. An opening formed through a side or bottom of the box defines a slab passage extending through the cooling bath and through which the cast slab moves. The wiper or seal member is removably positioned within the waterbox assembly via an end of the slab passage, and most preferably is provided as part of a modular seal assembly which is adapted for simplified removal and/or placement as an integral unit.

Another object of the invention is to provide a waterbox assembly for use with a casting machine operable to continuously vertically cast a metal slab, and which includes a slab passage which extends generally vertically through a waterbox assembly from an upper inlet end to a lower outlet end, and wherein a sealing member is removably positionable within the slab passage by sliding insertion through the slab passage inlet end.

Another object of the invention is to provide a waterbox assembly which has a housing having a slab passage sized to permit movement of a cast slab therethrough, and which together with the cast slab provides a series of multiple flow passages through the waterbox interior.

In a simplified construction, a waterbox assembly is provided for use with a casting assembly for use in forming a cast slab or billet (hereinafter generally referred to as a cast slab). More preferably, the waterbox assembly is provided for use in a vertical casting plant which is operable to continuously vertically cast a metal slab from a mould outlet.

The waterbox assembly includes a housing which is sized to retain a desired volume of cooling fluid or water therein. A slab passage formed through the housing extends vertically from an inlet end spaced proximate to the mould outlet, to a lower outlet end remote therefrom. The slab passage has a size and shape selected to permit substantially unhindered movement of the cast slab therethrough via the outlet end. In a most simplified

construction, the slab passage may be formed as a generally square or rectangular cavity or passage which is generally aligned with the vertical casting axis of the slab.

A wiper or seal member is slidably and/or removably disposed in the slab passage for engaging the sides of the cast slab to substantially prevent or restrict the flow of cooling fluid therepast. A cooling fluid source provides a volume of water or cooling fluid to the slab passage and about the portion of the slab therein, to assist in the cooling and hardening of the slab surfaces. Preferably, the seal member is provided as part of a modular cartridge which defines at least generally a lateral extent of a seal passage through which the cast slab moves. Optionally, the seal passage has a cross-sectional profile which is selected to enable movement of the slab therethrough, while maintaining generally fluid sealing contact between the seal member and with the slab side and/or edge surfaces.

Although not essential, most preferably when the seal passage is positioned or otherwise disposed in the slab passage, the seal passage generally aligns vertically directly beneath the mould outlet, with the slab and one, and preferably both of the waterbox sidewalls which define the total extent of the slab passage forming a flow path for coolant fluid therebetween.

In a further embodiment, the sidewalls which define the slab passage may be provided as inner sidewalls, with the housing having a further outermost sidewall spaced laterally therefrom, to define a reservoir space therebetween. Apertures or other suitable flow outlets formed through the inner sidewalls allow coolant fluid/water to flow from the inner fluid flow path past the inner sidewall, and into the surrounding reservoir space between the outer and inner sidewalls. Flow valves or regulators may furthermore be provided to adjust the rate of flow of coolant fluid from the inner flow path on each longitudinal side of the cast slab. In this manner, the flow of coolant fluid along each longitudinal side of the slab may be maintained at a substantially equal flow rate, minimizing the likelihood that one side of the slab may be differentially cooled relative to the other.

Suitable flow regulators include mechanical and/or solenoid valves. In a most preferred construction, however, a movable weir or intermediate sidewall may be positioned between the inner and outermost sidewalls. The weirs are adjustable in height relative to the

remainder of the reservoir housing and/or outermost sidewall to regulate the volume or flow of cooling fluid thereover.

Accordingly, in one aspect the present invention resides in a casting assembly waterbox includes a slab passage extending therethrough sized to permit longitudinal movement of a cast slab therethrough, the slab passage being elongated along a longitudinally extending axis and extending from an inlet end to an outlet end,

an interior sidewall defining at least part of said slab passage,

a seal member disposed in said slab passage and being removable therefrom through said inlet end, the seal member having a sealing edge generally defining a lateral extent of a seal passage having a cross-sectional profile selected for at least partial sealing contact with said slab as it moves longitudinally through said slab passage,

when said seal member is disposed in said slab passage, said seal passage and said slab passage being generally aligned, with said interior sidewall and said slab generally defining a first coolant flow passage therebetween,

an outer sidewall being spaced outward from at least part of said inner sidewall to define a fluid reservoir therebetween,

at least one fluid inlet providing fluid communication between said first flow passage and said reservoir.

In another aspect, the present invention resides in a casting waterbox for use in cooling a continuously vertically cast slab, the waterbox including,

a housing having a slab passage extending therethrough from an inlet end to an outlet end, the slab passage being elongated along a generally vertical axis, and being sized to permit movement of the cast slab vertically therethrough,

an interior sidewall defining a lateral extent of at least part of said slab passage, the sidewall extending from a proximate upper end portion to a distal lower end portion,

a removable seal assembly slidably positionable in said slab passage, the seal assembly defining a seal passage sized to permit movement of the cast slab vertically therethrough and including a seal member, the seal member extending generally laterally to an innermost sealing edge, the sealing edge having a profile selected for generally sealing contact with said slab as it moves vertically through said seal passage,

wherein with said seal assembly is positioned in the slab passage, said interior sidewall and said cast slab generally defining a first coolant flow chamber,

a vertically positionable outer sidewall being spaced laterally outward from at least part of said inner sidewall to define a second coolant flow chamber therebetween, the interior sidewall further including a plurality of fluid flow apertures spaced towards said outlet end providing fluid communication between said first coolant flow chamber and said second coolant flow chamber,

an outermost sidewall spaced laterally outward from at least part of the first outer sidewall to define a third coolant flow chamber therebetween, the outermost sidewall extends from a lower sidewall portion to an upper edge spaced generally vertically above an uppermost sidewall edge of the first outer sidewall, and

a cooling fluid supply to supply cooling fluid to said first coolant flow chamber as for example from a mould outlet, as said cast slab moves vertically through said slab passage.

In a further aspect, the present invention resides in a waterbox assembly for use in a casting machine operable to vertically cast a metal slab, the casting machine including a mould cavity for receiving molten material to be cast and having a mould outlet for casting said slab vertically therethrough, the waterbox assembly including,

a slab passage elongated along a generally vertically extending axis and extending from an upper inlet end spaced towards the mould outlet to a lower outlet end, the slab passage being sized to permit vertical movement of the cast slab therethrough, said slab passage being laterally defined in part by an opposing pair of interior sidewalls, and an opposing pair of end walls, each of the sidewalls extending from an upper end portion spaced towards the inlet end to a lower end portion remote therefrom, and including at least one fluid flow aperture formed therethrough,

a modular seal assembly having a seal passage extending therethrough having a profile generally corresponding to a cross-sectional profile of the cast metal slab, the seal assembly being sized for fitted insertion in said slab passage and including a seal member disposed radially about at least part of the seal passage and extending generally inwardly part way towards the axis to an innermost sealing edge, the sealing edge having a profile selected for general sealing contact with at least part of said slab as it moves vertically through said seal passage, and wherein when said seal assembly is positioned in said slab passage, said interior sidewall and said cast slab generally define a first coolant flow passage therebetween,

a support member disposed towards said outlet end to assist in retaining said seal assembly in an operative position in said slab passage with said seal passage generally co- axially aligned therewith,

an outer sidewall being spaced laterally outward from each respective inner sidewall to define a second coolant flow passage therebetween, the fluid flow apertures providing fluid communication between said first and second flow passages to permit cooling fluid flow from said first coolant flow passage into said second coolant flow passage.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference may now be had to the following detailed description taken together with the accompanying drawings in which:

Figure 1 illustrates a schematic side view of a continuous casting plant used in the vertical casting of metal slabs, and which incorporates a waterbox assembly in accordance with a preferred embodiment of the invention;

Figure 2 illustrates a perspective view of the waterbox assembly used in the casting plant of Figure 1 illustrating the movement of a cast slab therethrough;

Figure 3 shows a perspective view of a waterbox housing used in the waterbox assembly of Figure 2;

Figure 4 illustrates schematically a side view of the waterbox housing shown in Figure 3, illustrating the movement of the cast slab vertically therethrough;

Figure 5 illustrates a top perspective view of the waterbox housing shown in Figure 4;

Figure 6 illustrates a partial cross-sectional view of the waterbox housing sidewall shown in Figure 4 taken along lines 6-6;

Figure 7 illustrates an enlarged view of the waterbox sidewall construction shown as sectional view A in Figure 6;

Figure 8 illustrates a perspective view of a modular seal assembly cartridge used in the waterbox assembly of Figure 2;

Figure 9 illustrates a partial cutaway side view of the seal assembly cartridge shown in Figure 8;

Figure 10 illustrates a perspective top view of a wiper seal and seal support flange used in the seal assembly cartridge of Figure 8; and

Figure 11 illustrates a perspective top view of seal support flange shown in Figure 10.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 illustrates a continuous casting plant 10 which, as will be described, is operable to cast a metal billet or slab 14 continuously in the direction of arrow 100 (Figure 2) along a vertical casting axis Ay- Ay. In operation of the plant 10, the slab 14 is formed with a generally rectangular cross-sectional profile shown best in Figure 2, characterized by parallel opposing pairs of longitudinally elongated sides 13 a, 13b, and laterally extending ends 15a, 15b. It is to be appreciated, however, that cast slabs or billets having different cross- sectional shapes or profiles could equally be formed.

The plant 10 is provided with a casting machine 16 used to initially form the slab 14 from molten metal, a waterbox assembly 20, and a pair of pinch rolls 22 which assist in slab transport and production. The casting machine 16 includes a furnace 23, a tundish 25 and a mould 24. The mould 24 is provided with a lowermost mould outlet 26 through which the formed slab 14 emerges. The mould outlet 26 is provided as a rectangular opening corresponding in size to the desired cross-sectional profile of the slab 14, thus providing the slab 14 with its rectangular cross-sectional shape. The furnace 23 is operable to continuously melt and supply molten metal, such as copper, to the tundish 25 in a conventional manner. The tundish 25 in turn supplies the molten metal to the mould 24. Most preferably, the outlet 26 has a profile selected to form a slab 14 with a longitudinal length of between about 2000 and 8000 mm, and a lateral thickness of between about 50 and 250 mm, and preferably between about 100 and 220 mm, depending upon the metal material which is to be cast. The mould 24 is thus operable to continuously cast the slab 14 downwardly through the mould outlet 26 along the vertical casting axis Ay- Ay, with the intersection of the longitudinal mid- plane (P _L ) and lateral mid-plane (P _m ) of the formed slab 14 aligned therewith.

As will be described, the waterbox assembly 20 is operable to cool and help solidify the slab 14 immediately following its emergence from the mould 24, minimizing the possibility that the slab 14 may be damaged by the pinch rolls 22. The waterbox assembly 20 is constructed to retain therein a desired volume of cooling fluid 29, such as water, as a cooling bath through which the slab 14 vertically moves. A vertically extending slab passage 50 which extends through the water box assembly 50 from an open upper inlet end 31 to a lower outlet end 33 (Figure 4). The lower outlet end 33 is sealed against the slab 14 as it is cast, allowing the slab passage 50 to be filled with the cooling fluid 29 to effect slab cooling. Although not essential, most preferably the inlet end 31 of the waterbox assembly 20 is provided immediately vertically beneath the mould outlet 26 to effect slab cooling prior to the engagement of the slab 14 by the pinch rolls 22.

The pinch rolls 22 are shown best in Figure 1 as preferably spaced vertical distance beneath waterbox assembly 20 aligned with the axis Ay-Ay. As the slab 14 is cast, the pinch rolls 22 engage the lateral ends 15a, 15b and draw the newly formed slab 14 vertically downwardly along the casting axis Ay-Ay through the waterbox assembly 20. Once the slab 14 is sufficiently cooled, successive slab lengths are severed into transportable lengths for

further rolling and/or processing. The slab 14 may thus be continuously vertically cast and drawn downwardly through the waterbox assembly 20 by the pinch rolls 22, typically moving along the casting axis Ay-Ay at a casting rate selected at between about 1 and 20 cm, and preferably about 5 and 12 cm per minute.

Figure 2 shows best the waterbox assembly 20 as including a waterbox housing 30 and a modular seal cartridge 40 which is used to fluidically seal the outlet end 33 of the slab passage 50 as a live seal against the slab 14 as it moves therethrough. The seal cartridge 40 is adapted for simplified insertion into and removal from the housing 30. The modular nature of the seal cartridge 40 is selected to enable the cartridge 40 to be easily changed in the event of seal wear or failure, or upon a change in the configuration of mould outlet 26, when for example, to form a slab 14 having a differing shaped cross-sectional profile. Most preferably, the seal cartridge 40 is configured for insertion into position in the housing 30 by sliding insertion through the inlet end 31 of the slab passage 50.

The waterbox housing 30 is shown best in Figures 3 to 5 as being formed as a generally rectangular box-shaped construct having an open top, an outermost steel sidewall 32, and a partially closed steel bottom plate 34. Figure 5 shows the slab passage 50 as extending vertically through the centre of the housing 30 aligned with the axis Ay-Ay. A rectangular opening 36 is formed through the bottom plate 34 at the outlet end 33. The opening 36 is shown as having a dimension selected marginally smaller than a remainder of the passage 50, and is defined by a peripherally extending steel flange 35 which projects inwardly 1 to 3 cm towards the axis Ay-Ay. As will be described, the flange 35 has an overall dimension and structural integrity selected to seat and support the seal cartridge 40 thereon in operation of casting plant 10.

Within the housing 30, the longitudinal sides of the slab passage 50 are defined by a pair of generally planar sidewalls 38a,38b. Each of the sidewalls 38a,38b are vertically aligned, and are oriented a generally parallel orientation with the major side surfaces 13a, 13b and longitudinal mid-plane P _L of the cast slab 14 as it moves along the casting axis Ay-Ay. Each sidewall 38a,38b is joined at each vertical edge with an edge of one of an opposing pair of end walls 42a,42b. It is to be appreciated that the sidewalls 38a,38b and end walls 42a,42b are provided with a sufficient size and spacing so as to provide the slab passage 50 with an

overall dimension selected to not only avoid interference with the movement of the slab 14 therethrough, but also to permit the retention of a desired volume of cooling fluid 29 along the sides 13a, 13b and ends 15a, 15b of the cast slab 14. Although not essential, most preferably the sidewalls 38a,38b and end walls 42a,42b are provided having a mirror construction to each other, and such that when the waterbox assembly 20 is positioned beneath the mould 24, the axial centre of slab passage 50 substantially aligns with the casting axis Ay-Ay.

The end walls 42a,42b of the slab passage 50 are shown best in Figure 5 as extending in a generally vertical orientation, and generally parallel to the casting axis Ay- Ay. In the embodiment shown, the end walls 42a,42b include along each vertical edge, a vertically elongated enlarged pocket 44. Each pocket 44 presents a generally planar face surface 45 which is oriented parallel to and spaced laterally outward from the immediately adjacent sidewall 38. The pockets 44 provide for the retention of comparatively larger volumes of cooling fluid therein in corner regions of the cast slab 14. It is to be appreciated, however, that in a simplified construction, the end walls 42a,42b could be provided with a generally planar configuration, or for that matter depending on the side profile a curved or hexagonal construction.

The outer sidewall 32 of housing 30 is shown best in Figure 5 as being spaced outwardly from the axis Ay-Ay relative to each of the interior sidewalls 38a,38b and end walls 42a,42b, to provide the housing 30 a double wall construction, and define a fluid reservoir 52 therebetween. The outer sidewall 32 is shown in Figure 3 as having a generally rectangular construction, including a pair of elongated outer sidewall panels 74a,74b which are arranged generally parallel to and spaced from a respective inner sidewalls 38a,38b, and outermost end panels 76a,76b spaced a distance from the inner end walls 42a,42b, respectively. A pair of fluid drains 54a,54b are formed through each end panel 76a,76b adjacent to the bottom 34. The drains 54a,54b are provided in fluid communication with a fluid supply 58 (Figure 1) which recirculate water to the fluid supply, and thereafter initially into the mould 21 so as to flow downwardly into the house 30.

In operation of the waterbox assembly 20, the fluid supply 58 is operated to continuously provide a flow of coolant fluid 29 into the inlet end 31 of the slab passage 50.

Most preferably, the supply 58 is operable to supply coolant fluid 29 from the mould outlet 26 at a substantially equal flow rate downwardly along each longitudinal side 13 a, 13b of the slab 14.

As shown best in Figures 4 to 6, a pair of movable weirs 78a,78b are disposed in the reservoir 52 between each respective inner sidewall 38a,38b and the adjacent outer sidewall panel 74a,74b. The weirs 78a,78b extend vertically from a lower edge generally sealed against the housing bottom 34 by way of a sliding seal 89 (Figure 7) to an uppermost edge 80. The uppermost edge 80 of each weir isocated a vertical distance below the upper edges 84,86 of the adjacent inner and outer sidewalls 38a,38b,32. The weirs 78a,78b are provided as generally planar panels which are most preferably provided with a length and orientation selected such that a vertical edge of each weir 78a,78b is maintained in generally sliding fluid sealing contact with the face surface 45 of each adjacent fluid pocket 44.

As shown best in Figure 4, a series of fluid openings 84 are formed through a lower portion of the inner sidewalls 38a,38b adjacent to the housing bottom 34. The fluid openings 84 are sized to permit the flow of cooling fluid 29 in the direction of arrows 200a,200b downwardly along the slab passage 50, through the inner sidewalls 38a,38b and into the reservoir 52. As the fluid 29 flows into the reservoir 52, it moves initially upwardly between the inner sidewalls 38a,38b, and the adjacent weirs 78a,78b. The cooling fluid flows over the top edge 80 of each weir 78a,78b, returning as a downward flow between the weirs 78a,78b and the adjacent outermost sidewall panel 74a,74b, to flow outwardly through the fluid drains 54a,54b.

Although not essential, most preferably the weirs 78a,78b are vertically adjustable relative to a remainder of the housing 30. In a simplified construction, a series of threaded hand cranks 90 are provided which when turned, raise or lower each weir 78a,78b. Each hand crank 90 is coupled to a threaded rod/socket assembly 92 which when turned allows the upper edge 80 of each weir 78a,78b to be vertically repositioned. Preferably, the hand cranks 90 are adapted to permit the repositioning of the upper edge 80 of weirs 78a,78b to enable the substantial balancing and equalization of the flow of cooling fluid 29 over the entire length of upper edge 80 thereof. In this manner, the flow of cooling fluid 29 supplied to the slab passage 50 may be regulated to ensure that cooling fluid 29 flows along each longitudinal

side 13a, 13b of the cast slab 14 at a substantially constant and equal rate. The applicant has appreciated that the equal flow rate of cooling fluid 29 along each longitudinal side 13 a, 13b of the cast slab 14 minimizes the likelihood of differential cooling, and any resulting distortion or deflection of the cooled slab 14, as it passes through the waterbox assembly 20.

The seal cartridge 40 is shown best in Figures 8 and 9. The cartridge 40 has an overall maximum width W and length L selected to allow the sliding positioning of the cartridge 40 in the housing 30 through the open upper end 31 of the slab passage 50. The seal cartridge 40 is shown best in Figure 8 as having a generally rectangular seal passage 150 formed through its centre. The seal cartridge 40 is configured so that when positioned within the housing 30, the seal passage 150 assumes an orientation both centered within the slab passage 50 and in alignment with the casting axis Ay-Ay. The seal passage 150 has a size and profile which generally corresponds to the cross-section profile of the cast slab 14, and which is selected to maintain substantially fluid sealing contact therewith, as the slab 14 moves therethrough. As will be described, the periphery of the seal passage 150 is delineated by a series of resiliently deformable rubber or elastomeric wipers 114,134 which extend into the passage 150 to an innermost contact edge. The wipers sealingly engage the slab 14 as it moves downwardly from the slab passage 50, to substantially reduce or eliminate the leakage of cooling fluid 29 therefrom.

In a preferred construction, the seal cartridge 40 is provided with an upper seal array 110 and a lower seal array 130, which are joined by a flexible expansion assembly 160. The upper seal array 110 is shown best in Figure 8 as including a steel mounting flange 112 which has a primary rubber wiper 114 bolted thereto. Each of the mounting flange 112 and wiper 114 are provided with an open generally rectangular shape. The rectangular steel mounting flange 112 has an overall shape and structural rigidity selected to enable its seated placement against the support flange 35. The flange 112 has a profile somewhat larger than the remainder of the cartridge 40 and which is selected to enable its fitted insertion snugly within the slab passage 50 so as to locate in abutting contact against the support flange 35. A series of downwardly extending guide pins 116 are preferably mounted on a lower surface of the flange 112 for mated insertion within guide holes 118 (Figure 5) formed in the support flange 35, to ensure the correct seal cartridge 40/housing 30 alignment.

Optionally, a series of lift eyelets or grappling hooks 120 are mounted at spaced locations, projecting upwardly from an upper surface of the flange 114 for connection to a winch assembly (not shown) used to retrieve worn cartridges 40 from within the housing 30. The hooks 120 enable the entire cartridge 40 to be rapidly and easily raised from the slab passage 50, upon, for example, wear of the wipers 114,134.

The wiper member 114 of the upper seal array 110 is shown best in Figure 9 as being formed as a generally U-shaped rubber or another elastomeric material strip which extends inwardly towards the seal passage 150 to a double wall peripheral edge surface 122a, 122b. The peripheral edge surface 122 is positioned for resilient fluid sealing contact against the slab 14 as it moves therepast through the passage 150. The wiper 114 thus provides a primarily fluid seal between the seal cartridge 40, and the slab 14, as it moves downwardly from the slab passage 50 and into the seal passage 150.

The lower seal array 130 similarly includes a lower elastomeric wiper 134, as well as a metal seal support flange 136. The wiper member 134 is provided with a similar construction to wiper member 114 having a double wall peripheral edge surface 138a, 138b, and functions as a secondary fluid seal against the moving slab 14. The seal support flange 136 is positioned directly beneath the elastomeric wiper 134. As shown best in Figures 10 and 11, both the wiper 134 and support flange 136 are provided with a generally rectangular open interior having a cross-sectional profile corresponding to that of the cast slab 14. The support flange 136 is provided with a plurality of resiliently deformable bendable metal fingers 140 which are mounted on slides 142. The fingers 140 project inwardly into the seal passage 150 past the peripheral edge surface 138 of the wiper 134. The metal fingers 140 assist in biasing and maintaining sealing contact between the elastomeric seal member 134 and the slab 14 to prevent the movement of water therebetween. Although not essential, most preferably the deformable fingers 140 of the seal support flange 134 are adjustable on the slides 142 in the horizontal direction so as to be selectively movable into or away from the centre of seal passage 150, depending upon the degree of resiliency desired.

The expansion assembly 160 is most preferably provided with an elastomeric bellows 162 coupled respectively along its upper and lower edges to each wiper 114,132. A series of connecting stabilizing rods 164 extend vertically across the baffle 162 from the upper wiper

114 to wiper 134 and are bolted at each end thereto. The stabilizing rods 164, in combination with the flexible bellows 162, allow limited flection or deflection of the lower seal array 130 relative to the upper seal array 110. In this manner, the present construction advantageously allows the lower seal array 130 limited flexure or movement relative to the casting axis Ay- Ay, in the event some differential cooling and deformation of the cast slab 14 may, in fact, occur, thereby maintaining a fluid tight seal between the wiper 134 and slab sides 13a, 13b and ends 15a, 15b.

While the detailed description describes the casting plant 10 as operable to produce a slab 14 having a generally rectangular cross-sectional profile, and with the waterbox assembly 20 including a slab passage 50 and seal passage 150 having corresponding rectangular shapes, the invention is not so limited. It is to be appreciated that other mould outlet 26 configurations could be used to provide slabs 14 having differing profiles, with or without corresponding changes in the shape of the waterbox passages 50,150.

Although the detailed description describes and illustrates various preferred embodiments, the invention is not so limited. Many modifications and variations will now occur to a person skilled in the art. For a definition of the invention, reference may be had to the appended claims.