MXPA99005290A - It foundry device - Google Patents

Abstract

The twin cylinder strip casting apparatus in which a pair of side pond restriction plates (56) engage the end surfaces of the casting cylinders (16) to form lateral restriction closures for the pond. The plates (56) are mounted on side plate holders (82) connected to the horizontally acting pushing devices (83) that apply closing forces inwardly to the side plates (56). The pushing devices (83) are mounted on a pair of carriages (101) placed one on each end of the casting cylinder assembly and the spacing between them must be adjusted so that the carriages (101) can be preset before an operation cast iron to adapt to the width of cast iron cylinders (16). The carriages (101) are mounted on a central frame structure (103) that sits above the casting cylinders (1

Description

"STRIP FOUNDRY APPARATUS" BACKGROUND OF THE INVENTION This invention relates to the casting of metal strip. It has specific application to the casting of metal strip by continuous casting in a twin cylinder caster. In the twin-screw smelter, it is inserted between a pair of horizontal counter-rotation casting rolls that are cooled so that the metal hulls solidify on the surfaces of the movable cylinder and meet at the point of clamping between them to produce a solidified strip product supplied down from the point of attachment between the cylinders. The term "fastening point" is used herein to refer to the general region in which the cylinders are closer together. The molten metal can be emptied from a bucket into a smaller container or a series of smaller containers from where it flows through a metal supply nozzle placed above the attachment point in order to direct it to the attachment point between the cylinders, thus forming a molten metal melt tank, held on the casting surfaces of the cylinders immediately above the clamping point and - - which extends along the length of the fastening point. This pouring pond is usually restricted between side plates or dams which are retained in sliding engagement with the end surfaces of the cylinders to dampen the two ends of the pouring pond against the flow. The installation and adjustment of the cylinders and the restriction components of the metal supply and the pond in a twin cylinder smelter is a significant problem. The cylinders must be installed exactly to properly define an appropriate width for the fastening point, generally within the order of only a few millimeters, and there must also be certain means to allow at least one of the cylinders to move outward against a force of thrust to accommodate fluctuations in the thickness of the strip, particularly during initiation. The cylinders need to be changed between the castings in order to allow a different strip width to be cast and the cylinders must be replaced if the casting surfaces have been damaged or deteriorated in any way during casting. If the cylinders have to be changed in situ, a significant amount of potential casting time is wasted waiting for the casting components and the area surrounding them to cool. The new game of - - cylinders, once they are in place, have to be calibrated before melting so that the width of the attachment point can be pre-graduated. When ferrous metals are melted, it is necessary to preheat the refractory components of the metal and pond supply restriction means at very high temperatures before the melting step begins. Due to these reasons, it has been proposed to build twin-cylinder melters with removable components so that cylinders and pre-heated refractory components can quickly collect in an operating assembly and start casting before the preheated components are cooled significantly. . An example of a melter with movable cylinders and refractory components is disclosed in our Australian Patents Number 631728 and 637548 and in the corresponding North American Patents Nos. 5,184,668 and 5,277,243. The invention described in our Australian Patent Application Number 84244/98 allows the twin cylinder strip smelter to be constructed with a modular construction in which the casting cylinders are installed in a movable module easily movable in and out of the machine, and where the cylinders can be set exactly on the module, so that the clamping point is pre-graduated and placed exactly on the machine when the module is installed. This allows the cylinder to be fixed to be installed prior to the replacement of the modules for quick change of the cylinders between the castings. Nevertheless, the proper placement of the lateral pond restriction dams and the proper adjustment of the mechanisms to apply the lateral dams to the ends of the cylinders, remains a problem, particularly if the size of the cylinders is changed to allow it to melt a different width of the strip. A change in the width of the strip requires a similar change in the width of the metal supply nozzle and there must be an appropriate repositioning of the nozzle supports. Generally, there will also be a need for the replacement of other components that depend on the width of the casting pond, for example, any of the sealing elements that seal the chamber of the casting pond and any level sensor of the pond or chamber installed at one end. of the pond to examine pond conditions during casting. By means of the present invention, the side dams and the side dam applicators are mounted on a pair of carriages that can move in and out and that are pre-graded to appropriate positions with respect to the width of the casting pond. The side dams in this way can be quickly repositioned when the cylinders are changed due to any reason, for example, for a change in the width of the strip to be melted. In addition, the carriages can also be used to hold other components that need to be adjusted according to the width of the casting pond, for example, the nozzle end brackets, the cast iron tseals and the chamber assemblies.

COMPENDIUM OF THE INVENTION According to the invention, there is provided an apparatus for continuously melting metal strip comprising a pair of parallel casting cylinders forming a clamping point therebetween; a metal supply means for supplying the molten metal to the point of attachment between the cylinders to form a molten metal melt pond held on the surfaces of the casting cylinder immediately above the point of attachment; a pair of side plates of the tank for coupling the end surfaces of the cylinders whereby side restriction seals for the casting pond are formed; a pair of side plate holders to retain the side plates; a - - pair of thrusting devices that act generally, horizontally connected to the side and operable plate holders to apply closing forces inward opposite to the side plates; and a cylinder driving means for driving the casting cylinders in counter-rotation directions to produce a strip of solidified metal supplied downwardly from the clamping point; wherein the pushing devices are mounted on a pair of carriages placed one at each end of the casting cylinder assembly and movable towards and away from each other to allow the spacing between them to be adjusted so that the carriages can be pre-graduated before a casting operation to agree with the width of the casting cylinders and to allow them to serve as reaction stops against which the pushing devices react to apply the closing forces inwards to the side plates, and wherein both carriages are also mounted in a central frame structure that sits above the casting cylinders. Preferably, the metal supply means comprises an elongated metal supply nozzle placed immediately above the attachment point and a metal distribution container for distributing the metal to the nozzle. The metal supply nozzle - It can be composed of two or more pieces placed in end-to-end relationship. Preferably further, the frame structure provides a central nozzle positioning support for the metal supply nozzle. Preferably also, there is a carriage driving means that acts between the frame and the carriages to move the carriages towards and away from each other. Preferably, furthermore, the carriage driving means is capable of operating to adjust the carriages in any of a plurality of pre-graduated spacings in which they are generally set equidistant from the central nozzle positioning support. Preferably also, the carriages are provided with external nozzle end supports for holding the outer ends of the nozzle at sites, the separations of which are determined by the pre-graduated separation of the carriages. Preferably also, the end-to-end supports of the nozzle are mounted on the carriages to be equidistant from the central nozzle-positioning support when the carriages are in any of their predetermined spacings. The carriages can also be provided with sealing means for coupling the metal supply means to provide a cast-iron pond chamber sealed above the casting pond. When the metal supply means comprises a metal distribution container positioned above a supply nozzle, the sealing means can couple the end portions of the distribution container. At least one of the carriages can also be provided with a camera assembly to mount a camera to observe the casting pond during casting by which a generally constant relationship is maintained between the position of the chamber and the restricting lateral dam of respective pond. Preferably, the camera assembly is placed directly above the respective side dam structure.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be explained more fully, a specific embodiment will be described in some detail with reference to the accompanying drawings, in which: Figure 1 is a vertical cross-section through a strip melter constructed in accordance with with the present invention; Figures 2A and 2B are joined in the line A- to form a longitudinal cross-section through the important parts of the melter; Figure 3 is a side elevation of important parts of the melter, placed in accordance with the present invention; Figure 4 is a plan view of the components shown in Figure 3; Figure 5 is a vertical cross section amplified through the critical melter components at one end of the melter; and Figure 6 is a cross-section through certain components of the melter shown in Figures 3 to 5.

DESCRIPTION OF THE PREFERRED MODALITY The illustrated melter comprises a main machine frame 11 which supports a casting cylinder module in the form of a cassette 13 which can be moved to an operating position in the melter as a unit, but which can be easily removed when the cylinders are going to rest. The cassette 13 carries a pair of parallel casting cylinders 16 to which the molten metal is supplied during a ladle casting operation (not shown) through a refractory tundish 17, the distributor 18 and the supply nozzle 19 for Create a casting pond 30. The casting cylinders 16 are cooled with water so that the hulls solidify on the surfaces of the movable cylinder and meet at the point of clamping between them to produce a solidified strip product 20 at the outlet of the cylinder. This product can be fed to a normal furler. The casting cylinders 16 are made to counter-rotate through driving arrows 41 from an electric motor (not shown) connected with a transmission mounted on the frame of the main machine. The driving arrows can be disconnected from the transmission when the cassette is to be removed. The cylinders 16 have peripheral copper walls formed with a series of longitudinally extending water cooling passages that are circumferentially spaced, supplied with cooling water through the ends of the cylinder from the water supply conduits in the arrows 41 cylinder boosters that connect with the water supply hoses 42 through the rotary glands 43. The cylinder typically can be of a diameter of approximately 500 millimeters and up to 2000 millimeters long in order to produce a strip product about the width of the cylinders. The ladle is of entirely conventional construction and is supported on a rotating turret from where it can be brought to its position above the refractory tundish 17 to fill the refractory tundish. The refractory tundish can be equipped with a sliding gate valve 47 operable by a servo cylinder to allow the molten metal to flow from the refractory trough 17 through the valve 47, and the refractory shield 48 towards the distributor 18. The distributor 18 is also of conventional construction. It is formed as a wide source made of refractory material such as magnesium oxide (MgO). One side of the distributor 18 receives the molten metal from the refractory tundish 17 and the other side of the distributor 18 is provided with a series of longitudinally spaced metal outlet openings. The lower part of the distributor 18 carries the mounting brackets 53 for mounting the distributor to the frame 11 of the main caster when it is installed in its operating position. The supply nozzle 19 is formed as two halves identical placed end to end to form an elongated trough with the upper part open. Each half-nozzle is formed as an elongated body made of refractory material such as alumina graphite. The lower part of the nozzle is tapered so as to converge inwards and downwards so that it can project towards the clamping point between the casting cylinders 16. Its upper part is formed with outwardly projecting side flanges 55 which are placed on the nozzle supports in the manner that will be described below. The mouthpiece 19 may have a series of horizontally spaced flow passages that extend generally, vertically to produce an appropriate low speed discharge of metal across the width of the cylinders, and to supply the molten metal to the point of attachment between the cylinders, without directly hitting the surfaces of the cylinder where the initial solidification occurs . Alternatively, the nozzle may have a single continuous groove outlet for supplying a low speed curtain of molten metal directly to the point of attachment between the cylinders and / or may be submerged in the molten metal pool. The tank is restricted at the ends of the cylinders by a pair of side closure plates 56 which are retained against the stepped ends of the cylinders, when the cylinder cassette is in its operating position. The side closure plates 56 are made of a strong refractory material, for example, boron nitride, and have corrugated side edges to coincide with the curvature of the stepped ends of the cylinders. The side plates are mounted on the plate holders 82 which are movable by driving a pair of pushing devices 83 to place the side plates in engagement with the stepped ends of the casting cylinders, so as to form end closures for the pond cast metal formed in the casting cylinders during a casting operation. During a casting operation, the slide gate valve 47 is actuated to allow the molten metal to be emptied from the refractory tundish 17 to the distributor 18 and through the metal supply nozzle 19 from where it flows into the casting cylinders. The end of the head of the strip product 20 is guided by driving a mandrel table 96 from where it flows into the casting cylinders. The end of the head of the strip product 20 is guided by driving a mandrel table 26 towards the jaws of a reel (not shown). The apron table 96 hangs from the pivot assemblies 97 in the main frame and can be oscillated towards the reel by actuating a hydraulic cylinder unit (not shown) after the end of the clean head has been formed. The removable cylinder cassette 13 can be constructed in the manner described in our Australian Patent Application Number 84244/98 so that the casting cylinders 16 can be installed and the clamping point therebetween can be adjusted before the cassette is installed in the cassette. the position in the melter. The details of the construction of the cassette, which are fully described in Patent Application Number 84244/98, do not form part of the present invention and do not need additional description in this context. In accordance with the present invention, the pond restriction side plates 56 and the push devices 83 are mounted on a pair of carriages generally shown at 101 placed one at each end of the set of cylinders and movable towards and away from each other for allow the separation between them to be adjusted. The carriages in this way can be pre-graded before a casting operation to adapt the width of the casting cylinders and to allow rapid cylinder changes for different strip widths. The carriages 101 are hung from the linear rails 102 on the underside of the frame 103 of the fixed rectangular plate which is mounted on the frame of the main machine by clamp 104 so as to extend horizontally above the casting cylinders and extend further. beyond them at both ends of the melter. The rectangular plate frame 103 is placed below the metal distributor container 18 and has a central rectangular opening 105 for receiving the metal supply nozzle 19. The intermediate part of the frame 113 provides with supply nozzle supports 106 projecting inwardly to engage the upper flanges at the inner ends of the two half supply nozzle parts 19A and 19B, while the outer ends of the supply nozzle parts are held on the nozzle holder pins 107 mounted on the inner ends of the two carriages 101 so as to project into the opening 105 of the rectangular fixed frame to be movable in and out with the carriages 101. The side plates in the plate holders 82 are pivotally connected with the pushing devices 83 so that the side plates can be tilted around the pivot connections and the pushing devices apply opposite forces through the pivots. The pivot connections are provided in such a way that each side plate can be longitudinally oscillated from the cylinders by the pivoting movement about a horizontal pivot axis transverse to the cylinders and can oscillate laterally of the cylinders, by pivoting movement about of a vertical pivot axis perpendicular to the horizontal pivot axis, the pivotal movement of the plates being restricted to movement around those two specific axes so as to prevent the flat rotation of the plates. The side plate holders 82 are pivotally connected by means of horizontal pivot pins 126 and a pair of vertical pivot pins 128 to a body 129 of the pushing device at the end of a push rod 130 of the respective pushing device 83. The push rod 130 is held by a pair of linear bearings 120 on a rail 140 in the carriage. The vertical pivot pins 128 are fixed to the body 129 of the pushing device to fit within the elongated slots in the plate holder. The slots are elongated in the longitudinal direction towards the pushing device 83 to leave small clearance gaps around the pivot pins 128 which allow a limited oscillation movement of the plate holder around a pin 121 longitudinally of the cylinders.

The horizontal pivot pin 126 is also mounted on the body 129 of the thrusting device and engages an internally convex bearing in the plate holder so that the plate holder 125 can oscillate laterally of the casting cylinders about the vertical axis defined by the pins 128 of pivot. The degree to which the plate holder is free to oscillate in this manner can be limited by coupling with the stops on the body 129 of the pushing device. The horizontal pivot pins 126 are placed at a height above the level of the clamping point between the casting cylinders so that the effect of the outward pressure on the side plates due to the molten metal in the casting pond is such Such as to rotationally push the side plates around the pivots in directions such that their lower ends are pushed inward to produce an increased sealing pressure in the bottom or bottom of the casting pond. The arrangement allows the tilting of the side plates in order to accommodate the deformation of the end surfaces of the casting cylinder due to the thermal expansion during casting and at the same time, maintains a pushing action that increases the sealing forces in the casting. bottom of the pond to counteract the increased ferrostatic pressure in the bottom or bottom of the pond where there is correspondingly the highest tendency for escape or leakage. The proper placement of the pivots will depend on the diameter of the casting cylinders, the height of the casting pond and the thickness of the strip being cast. The manner in which the correct placement of the pivots can be determined is fully described in our Australian Patent Number 693256 and US Patent Number 5,588,479. The carriages 101 can be moved along the linear rails 102 in the frame 103 by operating a pair of fluid-driven cylindrical fluid positioning units 140, which can be operated pneumatically or hydraulically, fixed by studs 141 in the 101 and act against the stops 142 fixed in the frame of the main machine. The cylinder units 140 have two fixed positions so that they can adjust the carriages in two alternative positions for two different widths of cast strip. The adjustment of the carriages in this manner when the plate holders are automatically adjusted in appropriate positions in order to be put into engagement and pressed firmly against the ends of the casting cylinders by operation of the push devices 83. At the same time, the adjustment of the carriages 9, the external supply nozzle support pins 107 to positions for holding the outer ends of the core nozzle 19, appropriately to the width of the strip to be melted, since the relative positioning of the strip is maintained. the core nozzle supports and the plate holders. The carriages 101 also carry internal bridges 143 which are sealed against the outer ends of the dispensing container 18 through the seals 144. The bridges 143 are placed directly above the side plate holders 82 and will therefore fit against the ends of the container., of appropriate width distribution that is selected for the size of the strip to be melted, to thereby provide a sealed envelope above the casting pond to allow casting in an inert atmosphere. One or both of the bridges 143 can also serve as camera supports to hold the observation chambers of the casting pond to monitor the condition of the casting pond during casting. Specifically, each bridge may have perforations or other mounting means for mounting to the recesses 145 of the chamber extending inwardly and downwardly. With the above, the construction movement of the cars is effective to adjust not - - only the position of the lateral dams appropriate to the width of the strip to be melted, but also automatically places the bridges 143 with the seals 144 of the casting pond and the observation chambers of the casting pond without the need for adjustment or individual fixing of any of these components.

Claims (21)

1. - R E I V I N D I C A C I O N E S: 1.
2. An apparatus for continuously melting metal strip comprising a pair of parallel casting cylinders (16) forming a clamping point therebetween; metal supply means (17, 18, 19) for supplying the molten metal to the point of attachment between the cylinders in order to form a casting pond (30) of molten metal held on the surfaces of the casting cylinder immediately above of the attachment point; a pair of side plates of the tank (56) for coupling the end surfaces of the cylinders whereby side restriction seals for the casting pond (30) are formed; a pair of side plate holders (82) for retaining the side plates (56); a pair of thrusting devices acting generally horizontally (83) connected to the side plate holders (82) and capable of actuating to apply inward closing forces opposite the side plates (56); and a cylinder driving means (41) for driving the casting cylinders in counter-rotation directions in order to produce a strip of solidified metal (20) supplied downward from the clamping point; characterized in that the pushing devices (83) are mounted on a pair of carriages placed one on each end of the casting cylinder assembly movable towards and away from each other to allow the spacing between them to be adjusted so that the carriages (101) can be prefixed before a casting operation to adapt the width of the casting cylinders (16) and to allow them to serve as reaction stops against which the pushing devices react (83) to apply the closing forces inwardly to the side plates (56), and wherein in addition, both carriages (101) are mounted in a central frame structure (103) that sits above the casting cylinders (16) The apparatus according to claim 1, further characterized in that the metal supply means (17, 18, 19) comprise an elongated metal supply nozzle (19) positioned immediately above the attachment point and a metal distribution container (18) to distribute the metal to the nozzle.
3. 3. The apparatus according to claim 2, further characterized in that the metal supply nozzle (19) is composed of two or more pieces (19A, 19B) placed end to end.
4. The apparatus according to claim 2 or claim 3, further characterized in that the frame structure (103) comprises a rectangular frame positioned above and extending along the attachment point, the rectangular frame surrounds a central opening (105) to receive the nozzle (19).
5. The apparatus according to any of claims 2 to 4, which is further characterized in that the frame structure (103) provides a central nozzle positioning support (106) for the metal supply nozzle.
6. The apparatus according to any of claims 1 to 5, which is further characterized in that the carriages (101) are movable in linear rails (102) in the frame structure (103).
7. The apparatus according to claim 6, further characterized in that the carriages (101) are hung from the linear rails (102) below the structure of the frame (103).
8. The apparatus according to any of claims 1 to 7, which is further characterized in that there is a carriage driving means (140) acting between the frame structure (103) and the carriages (101) in order to move the cars (101) to and away from each other.
9. 9. The apparatus according to claim 8, further characterized in that the carriage driving means (140) comprises a pair of fluid-driven cylinder units., connected one to each of the cars (101).
10. 10. The apparatus according to claim 8 or 9, which is further characterized in that the carriage driving means (140) is capable of operating to fix the carriages in any of a plurality of prefixed separations where they are fixed in a generally equidistant manner. from a central part of the frame structure (103).
11. The apparatus according to claim 5, further characterized in that there is a carriage driving means (140) acting between the frame structure (103) and the carriages (101) to move the carriages (101) towards and far from each other and which is capable of operating to fix the carriages in any of a plurality of preset separations where they are generally equidistant from the positioning support of the central nozzle (106).
12. 12. The apparatus according to claim 11, further characterized in that the carriages are provided with end-to-end nozzle supports (107) to hold the outer ends of the - -nozzle (19) in locations, the spacing of which is determined by the predetermined separation of the carriages (101).
13. The apparatus according to claim 12, further characterized in that the external end supports of the nozzle (107) are mounted on the carriages (101) in order to be equidistant from the central nozzle positioning support (106) when the cars are in any of their prefixed separations.
14. The apparatus according to any of claims 11 to 13, further characterized in that the carriages (101) are movable in linear rails (102) in the frame structure (103).
15. 15. The apparatus according to claim 14, further characterized in that the carriages (101) are hung from the linear rails (102) under the structure of the frame (103).
16. 16. The apparatus according to any of claims 11 to 15, which is further characterized in that the carriage driving means (140) comprises a pair of fluid-driven cylinder units connected one to each of the carriages (101). - -
17. 17. The apparatus according to any of claims 1 to 16, further characterized in that the carriages (101) are provided with sealing means (143, 144) for coupling the metal supply means (17, 18, 19) in order to provide a cast iron tank chamber sealed above the casting pond.
18. 18. The apparatus according to any of claims 2 to 5, which is further characterized in that the carriages are provided with sealing means (143, 144) that couple the end portions of the dispensing container (18) in order to provide a chamber of the casting pond sealed above the casting pond. The apparatus according to claim 18, further characterized in that the sealing means (143, 144) comprise pond closure members (143) carried on the carriages (101) above the side plate holders (82). and equipped with stamps (144) for coupling the end portions of the distribution vessel (18). The apparatus according to any of claims 1 to 19, which is further characterized in that at least one of the carriages (101) is provided with a camera assembly (145) for mounting - - a camera in order to observe the casting pond during casting. The apparatus according to claim 20, further characterized in that the camera assembly (145) is placed on a carriage (101) on top of the respective dam structure (56).