IMPROVED METHOD AND ARRANGEMENT FOR COOLING THE BELTS OF CONTINUOUS BELT CASTING DEVICE

Abstract: In order to securely hold a moving belt (1, 2) of a continuous casting device against selective movable side plates (5, 6), a first group of rotatable control rods (19, 19A) which are disposed in a first supply header (16) and an adjacent exhaust header (17) are arranged to produce narrow high pressure zones in the cooling film (12) defined between the cooling pad (9) in which the headers (19, 19A) are formed and the moving belt (1 or 2). These zones can be selectively moved so as to follow and juxtapose the side plates (5, 6) when the mould gap between said plates is adjusted. A second group of rotatable control rods (19B, 19C) which are disposed in second and third supply headers (16) selectively heat the side portions of the belt (1 or 2) which are relatively cool as compared with the center portion thereof which is exposed to molten metal. When the side plate (5, 6) are moved away from each other the width of the belt side portions exposed to preheated coolant can be reduced and the amount of normal temperature coolant applied to the center portion thereof can be increased.

Description: The present invention relates generally to continuous belt casting devices for producing sheet or bar steel or the like and more specifically to a cooling arrangement therefor as well as to a method which is used to control the cooling of the belts during the casting process. Description of the Prior Art JP-A-58-38642 discloses an arrangement of the nature shown in Fig. 1 wherein two stationary side plates cooperate with a pair of circulating endless belts which define the basic elements of continuous belt casting devices. The side plates can be selectively moved toward and away from each other in a manner which permits the width of the casting mould gap to be varied within defined limits. Cooling pads are operatively disposed against the inner faces of the belt portions facing the mould passage in order to remove the heat imparted to said belt portions by the molten metal. This type of arrangement requires that the belt be held in contact with the side plates in a manner which obviates leakage and the formation of fins or similar imperfections along the edge of the casting device. JP-A-61-115625 discloses a cooling pad arrangement which is designed to provide a cooling film of coolant between it and the moving belt in manner which both removes excess heat from the belt and simultaneously provides sufficient hydraulic pressure to hold the edges of the belt against the side plates and to prevent the leakage of molten metal therebetween and the subsequent formation of the above mentioned fins. However, even though this arrangement provides sufficient pressure to hold the belt against the side plates, a problem is encountered in that the flow of coolant at or near the belt edges (which are not heated to the same degree as the center section of the belt) cools the same to a degree so that a temperature difference is produced between the edges of the belt and the center section thereof. This difference of temperatures induces a stress which acts in the moving direction of the belt and which reduces the working life of the same. SUMMARY OF THE INVENTION It is an object of the present invention to propose a method of controlling the cooling of belt portions in a continuous belt casting device as well as a cooling arrangement in such a device in order to provide sufficient pressure against the edges of the belt held in sliding contact with the side plates so as to obviate leakage and further to provide sufficient heat to the relatively cool edge sections of the belt so as to avoid an excessive temperature difference and obviate the appearance of a stress which reduces the life of the belt. The above object is achieved by a method of controlling the cooling of belt portions in a continuous belt casting device wherein opposite portions of a pair of moving endless belts are exposed to molten material on one face and cooled on the opposite face by a cooling pad provided in front and close to said opposite face and producing a coolant film within the narrow space provided between said pad and the corresponding belt portion, and wherein side plates are arranged between the opposite portions of said pair of moving endless belts so as to define with the latter a casting mould passage open on its upper and lower ends, said side plates being selectively movable toward or away from each other in a manner which permits the width of the mould gap defined therebetween to be changed within predetermined limits, said method being characterized by : using first and second rotatable control rod means disposed respectively in a first supply header and an adjacent exhaust header for : (a) producing narrow high pressure zones in the coolant film flowing in the space defined between the cooling pad in which the headers are formed and said corresponding moving belt portion, and for : (b) enabling said narrow high pressure zones to be selectively moved in order to follow and juxtapose the side plates when the mould gap between said side plates is adjusted ; and using third rotatable control rod means disposed in second supply headers for : (a) applying a pre-heated coolant for selectively heating the side or edge portions of said belt, which are relatively cool as compared with the center section thereof which is directly exposed to the molten metal, (b) changing the width of the zone within which the preheated coolant is applied against said side or edge portions in accordance with the distance between said side plates, and (c) changing the width of the mid-belt portion exposed to a coolant at normal cooling temperature in accordance with the change in width of the belt side portions to which said pre-heated coolant is applied. The above mentioned object is also achieved by a continuous belt casting device wherein opposite belt portions of a pair of moving endless belts are exposed to molten material on one face and cooled on the opposite face by a cooling pad provided in front and close to said opposite face and producing a coolant film within the narrow space between said pad and the corresponding belt portion , and wherein side plates are arranged between the opposite portions of said pair of moving endless belts so as to define with the latter a mould passage open on its upper and lower ends, said side plates being selectively movable toward or away from each other in a manner which permits the width of the mould gap defined therebetween to be changed within predetermined limits, the device being characterised by : first and second rotatable control rod means respectively disposed in a first coolant supply header and in an adjacent coolant exhaust header and designed for : (a) producing narrow high pressure zones in the coolant film flowing in the space defined between the cooling pad in which the headers are formed and said corresponding moving belt portion, and for : (b) enabling said narrow high pressure zones to be selectively moved in order to follow and juxtapose the side plates when the mould gap between said side plates is adjusted ; and by third rotatable control rod means disposed in a second supply header for : (a) applying a pre-heated coolant for selectively heating the side or edge portions of said belt, which are relatively cool as compared with the center section thereof which is directly exposed to the molten metal or alloy, (b) changing the width of the zone within which the pre-heated coolant is applied against said side or edge portions in accordance with the distance between said side plates, and (c) changing the width of the mid-belt portion exposed to a coolant at normal cooling temperature in accordance with the change of width of the belt side portions to which pre-heated coolant is applied. A further aspect of the invention deals with the particular structure of a cooling pad usable in a continuous belt casting device for cooling a surface of an endless belt portion adjacent thereto. The cooling pad structure, in addition to a first supply header formed therein and a first control rod rotatably disposed in each end section of the first header, comprises : a row of first supply ports which extends laterally across the coolant pad, the supply ports opening into the front face of said pad and communicating with the first supply header ; a first supply conduit of high pressure coolant, communicating with an outer end of a side portion of said first supply header; a second supply conduit of coolant under normal pressure, communicating with a center or mid-portion of said first supply header, said mid-portion being located adjacent to and between both side portions of said first supply header ; a first baffle arrangement provided on said first control rod, said first baffle arrangement being designed so as to isolate in a fluid tight manner said first conduit from said second supply conduit and to prevent any of the supply ports opening into said header side portions from communicating with said first supply conduit, or so as to present a narrow window opening through which high pressure coolant from the first conduit is supplied to a selected number of supply ports located in front of a side plate and so that, when the control rod is rotated between a first and a second rotational position, said narrow window opening moves from one end of the end section toward the other in a manner that coolant from the first supply conduit is supplied as a film of coolant defined between the belt and the pad in a predetermined zone or area moving laterally along the end section of the first header as the control rod is rotated between the first and second predetermined positions. Thanks to the above mentioned features it is possible to produce narrow high pressure zones in the film defined between the cooling pad and the moving belt, and to move selectively said high pressure zones so as to juxtapose the side plates when the gap between the side plates is adjusted. Especially with the help of a second supply header it is possible to selectively heat the edge portions of the belt which are relatively cool as compared with the belt center section exposed to molten metal. When the side plates are moved away from each other, the width of the edge sections which are exposed to pre-heated coolant is reduced and the amount of normal temperature coolant applied to the belt is increased accordingly. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be explained in detail with the help of the description given herebelow and the accompanying drawings of the preferred embodiment of the invention, which description and drawings, however, should not be taken as limiting the invention to the given specific embodiment but are given only for its explanation and understanding. In the drawings : Fig. 1 is a perspective view of a continuous belt casting device of the type to which the present invention is applied : Figs. 2(a) and (b) are respectively a schematic front view of the cooling pad arrangement according to the present invention showing the coolant flow pattern which is induced at the edges of the belt, and a side view of a vertical cross-section of the same part of the pad showing the location of the coolant supply and exhaust headers and ports ; Figs. 3(a) to 3(d) are plan views of horizontal cross-sections passing through the horizontal axes of the coolant supply and exhaust headers showing the provision of rotating control members which are disposed therein and which control the amount and pressure of the coolant supplied to the side or edge zones or areas of the endless belts in front of the pads ; Fig. 4 is a perspective view of a side part of the casting device showing the arrangement of the rotating control members in the respective headers and the connection means which enables a synchronous rotation of each of the said control members ; and Figs. 5(a) to 5(d) are respectively side views of a vertical cross-section and schematic views of a row of supply or exhaust ports with respect to the development of each of the control member arrangements represented in Figs. 3(a) to 3(d) showing the function of the partitions formed on the rotating control members and the control exerted by the same with respect to the supply and exhaust ports and flow path of the coolant and the pressure thereof. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is applied to the type of arrangement shown in Fig. 1. This belt casting device, as briefly described hereinbefore, includes two metal endless belts 1 and 2 which are supported on guide rollers 3a-3c and 4a-4c in the illustrated manner, and face each other so as to determine between two opposite and downwardly convergent belt portions, a casting mould gap laterally obturated by side plates 5 and 6 disposed between opposite side areas of the belts. These side plates 5, 6 are arranged to be selectively movable toward and away from each other in a manner which permits the width of the casting mould gap to be adjusted within predetermined limits. Refractory linings 5a and 6a are disposed on the inboard faces of the side plates 5 and 6 respectively. A delivery nozzle 7, through which molten metal or alloy is supplied into the casting device, dips into the mould gap delimited by the two opposite belts 1, 2 and the corresponding side plates 5, 6 as shown in Fig. 1. In the shown arrangement, the nozzle 7 has a diameter in excess of 100mm and the casted strip of metal or alloy 8, leaving the lower opening of the belt casting device, has a thickness of less than 50mm, and the upper opening of the belt casting device has a thickness greater than the diameter of the casting nozzle 7. As a result, the shape of the side plates 5, 6 and the refractory linings 5a and 6a as well as the vertical casting gap cross-section show the form of inverted triangles. Cooling pads 9 are disposed against the inner faces of the opposite parts of the belts 1 and 2 in a manner as illustrated so that the front face of a cooling pad 9 is disposed behind a belt portion exposed to the molten metal or alloy. These pads 9 as shown in Figs. 2a and 2b include a series of coolant supply ports 10 and a series of coolant drain or exhaust ports 11. These ports 10, 11 are respectively arranged in horizontal rows which are superimposed and extend laterally across the front face of the pads 9. In the prior art, the rows of supply and drain ports 10, 11 are arranged to alternate in the casting or belt travel direction in front of the cooling pads 9 (viz., the direction in which the belts 1 and 2 are driven). With the embodiment of the present invention, this order of the supply and drain port rows is also maintained. The supply and drain ports 10, 11 open onto the front face of a cooling pad 9 opposite to the corresponding endless belt portions and respectively communicate with coolant supply and exhaust headers 16, 17 which extend horizontally and laterally through the pads 9 and which supply coolant to and subsequently drain the same from a coolant film 12 which is established within a slit or narrow space defined between each belt 1 or 2 and the adjacent front face of the corresponding cooling pad 9. With this arrangement, the coolant discharged from each of the supply ports 10 tends to be distributed to four adjacent drain ports 11 in a manner such as depicted by the coolant flow arrows in Fig. 2a whereby the horizontal axes of the supply or drain ports 10 or 11 are disposed perpendicularly to the horizontal axis of a corresponding supply or exhaust header 16 or 17. The instant embodiment makes use of three distinct supplies of coolant. One is a normal or relatively low pressure supply (NP) which is fed via supply conduits or inlets 22NP into the supply headers 16 at locations provided essentially at the mid section or portion thereof ; the second one is a high pressure (HP) supply which is connected via conduits or inlets 20HP to selected supply headers just inboard of the ends thereof and the third coolant supply is formed by a preheated high temperature coolant, which is supplied via conduits 22HT to selected supply headers just inboard of the ends thereof. The present embodiment further comprises first pairs of adjacent supply and exhaust headers to provide adequately high pressure and low fluid volume flow zones which produce the required pressure to prevent leakage between a side plate and the belt and second pairs of adjacent headers to heat the cool sections or portions of the belt in a manner to reduce the difference of temperatures which induces the life reducing stress discussed hereinbefore. Each of the supply and drain headers 16, 17 constituted by horizontal cylindrical transverse bores in the cooling pad 9 are provided with two rotatable control valves or rods 19 (one in each end or side portion) which cover or uncover at least one of the ports 10, 11 and control the mode of supply and drainage of coolant at the side portions of the coolant film 12. It should be noted that the mid-portion of a header 16 or 17 located between two adjacent side or end portions of the same header is not provided with any rotatable control valve or rod so that the coolant entering this mid-portion is flowing through the corresponding ports 10 or 11 without being hindered by any obstacle. Generally speaking, the length of the mid-portion of the header defines the minimum width Wmin of the casting mould gap and may be equal to the length of a side portion of the corresponding header. As shown in Fig. 4 the control rods 19 are provided with an end part protruding from one side of the pad 9, each of said protruding end parts supporting a cog or gear of a plurality of cogs or gears intermeshing in a manner which interconnects the same and enables the selective synchronous contra-rotation of each rod of a pair of rods. Figs 3 (a) and 3(b) show in detail a first pair of supply (16) and exhaust (17) headers. The control rods 19 disposed in the supply header 16 have a sealing disk (no numeral) at the outboard ends thereof which tightly closes the header and prevents the wasteful loss of coolant. The high pressure supply control rods 19 (as they will be referred to hereinafter) further have a sealing disk on their inboard ends. Horizontal ports 23 extending parallely to the header axes and formed in the inboard sealing disk provide limited fluid communication between the mid-section or portion of the supply header 16 supplied with coolant under normal pressure and the side sections or portions of the header containing each a high pressure supply control rod. The high pressure supply control rods 19 are further provided with a helical baffle arrangement 18 which defines first and second fluid channels 21 and 24 within the header portions occupied by said control rods 19. The first channel 21 is isolated or separated in a fluid tight manner from the second one 24 by the baffle 18 and arranged to receive the high pressure coolant from conduit or inlet 20HP. The second channel 24 is arranged to communicate with the central or mid-portion of the supply header 16, into which low pressure coolant is supplied via conduit or inlet 22NP and coaxial ports 23. In this arrangement, the helical baffles 18 also define in front of a row of ports a helical opening or window via which the high pressure coolant supplied via conduits 20HP can be delivered to a limited number of the supply ports 10 which open into the side portions in which the control rods 19 are disposed. It should be noted at this point that the instant embodiment of the present invention is also arranged so that all of the control rods (19, 19A, 19B and 19C) extend within the side portions of the respective headers to the ends of the rod-free mid-portion of the header, which corresponds essentially to the minimum clearance of the casting mould defined between the side plates 5, 6. In other words, the control rods are arranged to span the zones or areas within the side plates 5, 6 which are movably adjustable. Figs. 3(a) - (d) show the side plates 5, 6 moved to positions between which the minimum mould gap or width is defined. The reason for this will become more apparent hereinafter. The operation of the arrangement shown in Fig. 3(a) is such that during casting, high pressure coolant is supplied to the supply header 16 via the side conduits or inlets 20HP while the lower pressure coolant is fed into the central portion thereof via the central conduit or inlet 22HP. As shown in Fig. 5(a), when the control rods 19 are rotated to a position wherein the imaginary line A is aligned with the row of supply ports 10, the helical baffles 18 are located and arranged so that the high pressure coolant is supplied only to the supply ports 10 in the narrow range W1 to W2 opening into the helical channel 21. Thus, as the control rods 19 are rotated in the direction which brings an imaginary line B into alignment with the row of supply ports 10, the narrow zone or window facing the supply ports 10 and in which high pressure coolant is supplied, moves in the outboard direction until only the ports W4 to W5 to the row of ports are supplied. Thus, the areas into which high pressure coolant is injected follow the move of the side plates 5, 6. It will be noted that the supply ports 10 are arranged so that at the minimum width setting of the side plates 5, 6, the most inboard high pressure supply ports 10 (or W1 to W2) are located in front of the corresponding side plate 5 or 6 while at the maximum width setting of said side plates 5, 6, the most outboard high pressure supply ports 10 (or W4 to W5) are located in front of said side plates 5, 6. Hence, by rotating the control rods 19 shown in Fig. 3(a) in accordance with the setting of the side plates 5, 6, it is possible to control the location of the areas into which high pressure coolant is supplied so that the force produced by the jets of high pressure fluid ejected from the supply ports into the film 12, acts in a relatively narrow zone directly opposite a corresponding plate 5 or 6. This relatively high pressure and relatively low volume fluid flow zone ensures that the belt is biased against the frontal face of the side plates 5, 6 in manner which tends to prevent the leakage of molten metal or alloy contained in the casting mould. The control rods 19A shown in Fig. 3(b) which control the adjacent row of exhaust ports 11 provided in the exhaust header 17 are constructed so that the helical baffles 18 permit at least one of the exhaust ports 11 which, on their inner end, open into the side portions of the exhaust header 17 to communicate with the part of the side portions connected to the mid-portion of said exhaust header 17, thus enabling draining of the coolant which enters the exhaust headers through those exhaust ports 11. When the side plates 5, 6 are moved to the positions in which the width of the mould gap therebetween is minimized, the control rods are set so that line D is aligned with the row of drain ports 11 while, when the maximum width Wmax of the mould gap between the side plates 5, 6 is selected, the control rods are rotated to the position wherein line C is aligned with the ports. The helical baffles on the control rods 19A are arranged to partition the side sections or portions of the exhaust header 17 in which the rods 19A are received into a first and a second channel. Among these two channels, only inboard channel 25 is permitted to establish communication between the exhaust ports 11 and the central or mid-portion of the exhaust header via the ports 23 formed in the inboard sealing disk of the corresponding rod 19A. When the control rod 19A is rotated into a position in which line D is aligned with the row of exhaust ports 11, only a limited number of the ports 11 at the inboard end of the row are able to communicate with the discharge conduit or outlet 22A via the coaxial ports 23. As the rod 19A is rotated toward the position corresponding to line C, its channel 25 approaches and finally aligns with the row of ports 11 and the number of exhaust ports 11 which are in communication with channel 25 increases toward the maximum number. In the instant embodiment the control rods 19 and 19A are interconnected in rotation by the gears G. Therefore, when the control rod 19 of the supply header 16 is rotated in the direction which brings line B toward the row of supply ports 10, the control rod 19A of the exhaust header 17 is simultaneously rotated in the opposite direction and in manner which brings line C toward the row of drain or exhaust ports 11. Hot or pre-heated coolant, for example water or a similar liquid at a temperature of about 95°C, is fed through the side conduits or inlets 22HT into the supply header 16 (Fig. 3c) in which control rods 19B are disposed. In this arrangement, the helical baffle 18 formed on the rod 19B has such a configuration that the high temperature coolant is prevented from communicating with the central or mid-portion of the supply header via ports 23. In other words, the baffles 18 subdivided the side-sections or portions of the supply header 16 in which control rods 19B are disposed into two channels 27 and 28 which are separated from each other in a fluid tight manner. Each of the channels 27 communicates through the high pressure conduit or inlet 22HT with the source of high temperature coolant while each one of the channels 28 communicates with the central or mid-portion of the header via the coaxial ports 23. As best seen in Figs. 3(c) and 5(c), the rod with its baffle 18 is arranged so that when the side plates 5, 6 are moved to the positions corresponding to the minimum width Wmin of the mould gap, both control rods 19B of the supply header 16 are rotated to the position wherein line E is aligned with the supply ports 10. Under these conditions, all of the supply ports 10 in the range of W1 to W4 communicate with channel 27 and are supplied with pre-heated coolant. As the side plates 5, 6 are moved from their minimum width positions to the positions corresponding to the maximum width Wmax of the mould gap, the control rod 19B is rotated to the position wherein the line F is aligned with the row of supply ports 10. Under these conditions only the ports W3 to W4 in the port range W1 to W4 are able to discharge heated coolant into the coolant film 12 between the cooling pad 9 and the corresponding belt 1 or 2. The reason for this arrangement is that when the side plates 5, 6 of the belt caster device are moved to their minimum width position Wmin, the widths of the belt side portions not heated by direct exposure to the molten melt are maximized. Under these conditions there is a high risk of a large temperature difference development and it is necessary to heat these relatively cool band or belt portions along each side of the belt. However, when the side plates 5, 6 are moved away from each other and toward their maximum width position Wmax, the width of the unheated band or belt portions narrows considerably. Thus, the amount of heat required for avoiding a too important temperature difference is reduced. The header arrangement shown in Fig. 3(d) and 5(d) is designed for use in locations where it is required to conserve the amount of coolant which is used and wherein it is not necessary to control the pressure of the coolant film 12 produced between the belt 1 or 2 and the corresponding cooling pad 9. In this case, the baffle 18 provided on rod 19c subdivides each side portion of the supply header 16 into two channels amount which the inboard channel 29 communicates permanently through the coaxial ports 23 with the central or mid-portion of that supply header 16 while the outboard channel is blind or fully occupied by a part of the control rod 19c. For example, the rods 19c shown in this figure 3(d) can be disposed in downstream locations with respect to the casting direction (viz., the direction of the metal strip 8 and the belt run adjacent said metal strip) and in the lower portion of the cooling pad 9. This type of rod can also be used at locations upstream of the molten metal meniscus level. When the side plates 5, 6 are moved away from each other in order to increase the mould width from the minimum width Wmin (Fig. 3) to the maximum casting width Wmax, the control rods 19c can be rotated gradually from a position corresponding to line H in Fig. 5(d), in which only the most inboard port W1 communicates with channel 29, to a position corresponding to line G in Fig. 5(d) in which all the supply ports W1 to W2 of the row of ports 10 communicate with channel 29 and are therefore connected to the central supply conduit or inlet 22HP, to control the width of the area to which the coolant fluid is supplied and thus effect the above mentioned coolant economy while ensuring that the coolant film 12 in the area between the side plates 5, 6 is maintained at the desired thickness. Merely by way of example, it is possible to provide the above described arrangements from the top to the bottom of the cooling pads 9 in the following sequences. Note that in the following sequences the rods shown in Figs. 3(a) to 3(d) will be denoted simply as a, b, c and d. I. a-b-a-b-a-b-a-b-d-b-d-b-d (note that the first d rod is located more than half-way down the pad) ; II. d-b-d-b-a-b-a-b-a-b-d-b-d-b-d-b-d (note that in this sequence the first and second d rods are disposed above the level of metal meniscum) ; III. d-b-a-b-a-b-a-b-a-d-b-o-o-o-o-o (in this sequency "o" denotes headers which are not provided with control rods) ; IV. d-b-c-b-c-b-c-b-c-b-c-b-c-b-c-b-c (this sequence primarily aims at belt temperature control) ; V. d-b-c-b-a-b-a-b-a-b-c-b-c-b-c-b (for pressure control in the upper sections and temperature control in the following section) ; and VI. d-b-c-b-a-b-c-b-a-b-c-b-c-b-c-b (for pressure control and wherein pre-heated coolant is not required). It should be noted that it is necessary to alternate supply and drain headers. Accordingly, it will be understood that the headers denoted by "o" in example III, in fact denote uncontrolled supply and drain headers arranged in alternating sequences. As will be obvious to those skilled in the art to which the present invention pertains many other sequences of control rods are possible and can be selected on the basis of the pressure and temperature control demands of the casting system. While the present invention has been disclosed in terms of the preferred embodiment in order to facilitate better understanding of the invention, it should be appreciated that the invention can be embodied in various ways without departing from the invention set out in the appended claims.

Claims: Method of controlling the cooling of belt portions in a continuous belt casting device wherein opposite portions of a pair of moving endless belts (1, 2) are exposed to molten material on one face and cooled on the opposite face by a cooling pad (9) provided in front and close to said opposite face and producing a coolant film (12) within the narrow space between said pad (9) and the corresponding belt portion, and wherein side plates (5, 6) are arranged between the opposite portions of said pair of moving endless belts (1, 2) so as to define with the latter a casting mould passage open on its upper and lower ends, said side plates (5, 6) being selectively movable toward or away from each other in a manner which permits the width of the mould gap defined therebetween to be changed within predetermined limits, characterized by : using first and second rotatable control rod means (19, 19A) respectively disposed in a first supply header (16) and an adjacent exhaust header (17) for : (a) producing narrow high pressure zones in the coolant film (12) flowing in the space defined between the cooling pad (9) in which the headers (19, 19A) are formed and said corresponding moving belt portion (1, 2), and for : (b) enabling said narrow high pressure zones to be selectively moved in order to follow and juxtapose the side plates (5, 6) when the mould gap between said side plate (5, 6) is adjusted ; and by using third rotatable control rod means (19B) disposed in second supply headers (16) for : (a) applying pre-heated coolant for selectively heating the side or edge portions of said belt (1 or 2), which are relatively cool as compared with the center section thereof which is directly exposed to the molten metal or alloy, (b) changing the width of the zone within which the preheated coolant is applied against said side or edge portions in accordance with the distance between said side plates (5, 6), and (c) changing the width of the mid-belt portion exposed to a coolant at normal cooling temperature in accordance with the change in width of the belt side portions to which preheated coolant is applied. A continuous belt casting device wherein opposite portions of a pair of moving endless belts (1, 2) are exposed to molten material on one face and cooled on the opposite face by a cooling pad (9) provided in front and close to said opposite face and producing a coolant film within the narrow space between said pad and the corresponding belt portion, and wherein side plates (5, 6) are arranged between the opposite portions of said pair of moving endless belts (1, 2) so as to define with the latter a casting mould passage open on its upper and lower ends, said side plates (5, 6) being selectively movable toward or away from each other in a manner which permits the width of the mould gap defined therebetween to be changed within predetermined limits, characterized by : first and second rotatable control rod means (19, 19A) respectively disposed in a first coolant supply header (16) and in an adjacent coolant exhaust header (17) provided in said cooling pad (9) and designed for : (a) producing narrow high pressure zones in the coolant film (12) flowing in the space defined between the cooling pad (9) in which the headers (19, 19A) are formed and said corresponding moving belt portion (1 or 2), and for : (b) enabling said narrow high pressure zones to be selectively moved in order to follow and juxtapose the side plates (5, 6) when the mould gap between said side plate (5, 6) is adjusted ; and third rotatable control rod means (19B) disposed in second supply headers (16) for : (a) applying pre-heated coolant for selectively heating the side or edge portions of said belt (1 or 2), which are relatively cool as compared with the center section thereof which is directly exposed to the molten metal or alloy, (b) changing the width of the zone within which the preheated coolant is applied against said side or edge portions in accordance with the distance between said side plates (5, 6), and (c) changing the width of the mid-belt portion exposed to a coolant at normal cooling temperature in accordance with the change in width of the belt side portions to which preheated coolant is applied. A continuous belt casting device as claimed in claim 2, characterized in that the cooling pad (9), in addition to said first supply header (16) formed therein and said first rotatably control rod (19) disposed in each of the side portions of said first header (16), further comprises : a row of first supply ports (10) which extends laterally across the coolant pad (9), said supply ports opening into the front face of said pad and commmunicating with said first supply header (16) ; a first supply conduit (20HP) of high pressure coolant, communicating with an outer end of a side portion of said first supply header (16) ; a second supply conduit (22NP) of coolant under normal pressure, communicating with a center or mid portion of said first supply header (16), said mid-portion being located between and adjacent to both side portions of first said header ; a first baffle arrangement (18) provided on said first control rod (19), said first baffle arrangement (18) being designed so as to isolate in a fluid tight manner said first conduit (20HP) from said second conduit (22NP) and to prevent any of the supply ports (10) which open into said header side portions from communicating with said first conduit (20HP) of coolant, or so as to present a narrow window (21) through which high pressure coolant from said first conduit (20HP) is supplied to a selected number of supply ports (10) and which moves from one end of said side portion toward the other in a manner that high pressure coolant from said first conduit (20HP) is injected as coolant film (12) in a predetermined zone located between said belt (1 or 2) and said pad (9) and able to move laterally along said side portion of said first header (16), when the control rod (19) is rotated between first and second predetermined positions. A continuous belt casting device as claimed in claim 2, characterized in that said pad (9), in addition to said first exhaust header (17) formed therein adjacent said first supply header (16) and having two side portions and central or mid-portions between and adjacent to said side portions, and said second rotatable control rod (19A) received in the side portion of said first exhaust header (17) further comprises : a row of first drain ports (11), said first drain ports being arranged to communicate with said first exhaust header (17) and to extend transversally along said pad (9) essentially parallel with said row of first supply ports (10) ; a drain conduit (22A) which communicates with the center portion of said exhaust header (17) ; a second baffle arrangement (18) formed on said second control rod (19A) and designed to selectively change the number of first drain ports (11) which are able to communicate with said drain conduit (22A) when said second control rod (19A) is rotated from a first predetermined position to a second predetermined position. A continuous belt casting device as claimed in claims 2 or 4, characterized in that said cooling pad (9) further comprises a first drive connection (G) which interconnects said first and second control rods (19, 19A) in a manner which induces synchronous rotation thereof. A continous belt casting device as claimed in anyone of claims 2 to 4, characterized in that said cooling pad (9) further comprises : a second supply header (16) having two side portions and a center or mid-portion ; a row of second supply ports (10), communicating with said second supply header (16) ; a supply conduit (22HT) of pre-heated coolant, communicating with said side portion ; a third rotatable control rod (19B) received in each of the side portions of said second supply header (16) ; a third baffle arrangement (18) formed on said third control rod (19B) and designed to selectively change the number of second supply ports (10) which are able to communicate with said supply conduit (22HT) of preheated coolant when said third control rod (19B) is rotated from a first predetermined position to a second predetermined position. A continuous belt casting device as claimed in claim 6, characterized in that said pad (9) further comprises : a third supply header (16) formed therein and having two side portions and a center portion communicating with a central supply conduit (22NP) for a coolant of normal pressure and temperature ; a row of third supply ports (10) communicating with said third supply header (16) ; a fourth rotatable control rod (19C) received in the side portion of said third supply header (16) ; a fourth baffle arrangement (18) formed on said fourth control rod (19C) and designed to selectively change the number of the third supply ports (10) which are able to communicate with said central supply conduit (22NP), when said fourth control rod (19C) is rotated from a first predetermined position to a second predetermined position. A continuous belt casting device as claimed in claims 2 to 7, characterized in that said cooling pad (9) further comprises a drive connection means (G) which interconnects said first, second, third and fourth control rods (19, 19A, 19B, 19C) in a manner wherein synchronous rotation thereof is selectively induced.

Inventors: BESSHO, NAGAYASU C/O KAWASAKI STEEL CORP., FUJII, TETSUYA C/O KAWASAKI STEEL CORP., KIMURA, TOMOAKI C/O HITACHI LIMITED, MORIWAKI, SABURO C/O KAWASAKI STEEL CORP., TOZAWA, HIROKAZU C/O KAWASAKI STEEL CORP., YASUKAWA, NOBORU C/O KAWASAKI STEEL CORP.
Applicants: HITACHI, LTD., KAWASAKI STEEL CORPORATION
Application year: 1987
Main classification: B22D11
IPC codes: B22D11