Hazelett Strip-Casting Corporation

Jerome B Allyn

Wojtek S Szczypiorski

Dean A Boozan

John F Wood

R William Hazelett

Timothy Dean Kaiser

Charles D Dykes

Norman J Bergeron

S Richard Hazelett

J F Wood

Robert J Carmichael

John E Pennucci

James G Villa

Charles R Simon

Thomas S Graham

George Desorcie

Frank E Kalaskie

Nedeltcho P Kandev

Woitek Szczypiorski

Method, system and apparatus for controllably heating copper alloy dam blocks in revolving edge dam chains in twinbelt continuous casters by induction heating of thermally-sprayed ferromagnetic layers bonded in shallow depressions in such blocks. High thermal conductivity of such blocks advantageously quickly conducts inductive heat from ferromagnetic layers into the blocks. For casting a slab of electrolytic anodes having aligned opposed protruding lugs, such chains include uniformly spaced lug-molding pocket blocks. Periodic induction heating of ferromagnetic layers on dam blocks of one chain or the other keeps pocket blocks aligned as revolving chains travel downstream along opposite sides of moving mold casting regions. Directly induction heating copper alloy dam blocks is very impractical. Therefore, ferromagnetic layers are thermally sprayed into depressions in blocks prior to assembling such chains. Pancake-type induction heaters inductively heat ferromagnetic layers of revolving dam blocks as they return toward a caster's entrance.

Method, system and apparatus for continually synchronizing travelling movement of two revolving edge dams in a continuous casting machine

Electrostatic application of a dusting of dry, electrostatically adherable, thermally insulative powder particles over a workface of a continuous metal-casting machine in which the mold surface or surfaces which provide the workface or workfaces revolve in a generally oval course. A dry dusting of protective powdery refractory material is applied to the workface after being entrained in an air stream and electrostatically charged by suitable electrostatic apparatus. The workface to be dusted is electrically grounded for attracting the charged powder particles for adhering them to the workface. The resultant coating formed by the dusting so deposited is remarkably uniform over a substantial area of the workface, a phenomenon explainable by mutual electrostatic repulsion of the dry powder particles being deposited. Continuously re-applied dusting over the workface during a continuous cast provides an immediately useful repair or replacement of dusting powder lost from the coating on the workface of a revolving mold surface during casting. The dusting may be removed at will by means of an air knife.

Method and apparatus for continuous casting of metal

Electrostatic application of a dusting of dry, self-adhering, thermally and electrically insulative powder particles over a work face of an endless, thin, flexible, water-cooled, metallic casting belt advantageous for use in a continuous metal-casting machine. A dry dusting of protective powdery refractory substance is applied to the belt after being rendered airborne and electrostatically charged by various embodiments of suitable electrostatic apparatus. The casting belt to be dusted is electrically grounded for attracting the charged powder particles for adhering them to the casting belt. The dusting so deposited is remarkably uniform over a substantial area, a phenomenon explainable by mutual electrostatic repulsion of the dry powder particles being deposited. Continuously re-applied dusting over the work face of an endless casting belt during a cast provides an immediately useful repair of lost dusting powder. The dusting may be removed at will by means of an air knife. Certain powders that are effectively soft afford high thermal insulativity for the metallic casting belt, and desirably they cause only minimal interference with further mechanical processing of a cast metallic product into which they might inadvertently become entrained.

Electrostatic application of insulative refractory dust or powder to

For closing gaps between blocks of a moving edge dam prior to its travelling downstream into the entrance of a moving mold defined between upper and lower revolving casting belts moving downstream from the mold entrance to its exit, the moving edge dam is initially elevated into a crest, as shown in FIGS. 12 and 14. This crest is above a plane generally defined by the lower casting belt travelling downstream. Then, a guide roller positioned above thrusts downwardly upon the moving edge dam bending it convex downwardly as shown at 'B' in FIG. 14 for causing its dam blocks to press against each other for sliding them along their high strength endless flexibile carrying member, thereby closing gaps between the blocks entering the mold entrance for sealing the entrance against outward leakage of molten metal between blocks. The downward convex bending also produces desired downward pressure of the moving edge dam against the lower casting belt, thereby enhacing sealing action between moving edge dam and lower belt. The downward thrust of this roller is sensed for indicating the amount of tension in the endless flexible carrying member of the moving edge dam. Back-breaker apparatus in rolling contact with a moving edge dam during its sagging return travel from mold exit to mold entrance has remotely controllable lift means for controllably raising or lowering the sagging edge dam for respectivley increasing or decreasing tension of the endless flexible carrying member.

Edge dam tensioning and sealing method and apparatus for twin-belt

A method and belt composition for improving the performance and flatness of thin revolving flexible casting belts of continuous casting machines wherein at least one wall of the moving mold is provided by a thin flexible endless metallic casting belt having a permanent insulative coating with fluid-accessible porosity in this permanent coating. Contrary to prior methods and apparatus which have sought to protect the wide thin casting belts, the present method for improving belt flatness and performance involves providing a Helium-containing gaseous film between the metal and the front face of the casting belt which is coated with a permanent insulative porous coating. For significantly improved results, this gaseous film contains at least 8 percent and preferably 15 percent and optimally 20 percent or more of Helium by volume and is non-reactive with the metal being cast, resulting in a controlled increase in the rate of heat transfer and for causing such heat transfer to become more nearly uniform and stabilized across the width of the flexible casting belt than in prior continuous casting machines of the same moving mold cross-sectional shape and size. The freezing rate advantageously becomes stabilized at a substantially higher and more uniform rate, the belt flatness becomes stabilized and the cast metallic product is thereby substantially improved both in metallurgy and surface appearance. Also, copper or copper alloy casting belts are used in certain embodiments for enhancing heat-transfer effects and belt flatness. During casting at a given speed, the freezing rate and exit temperature of the metal being continuously cast can be controlled by varying the helium percentage in the gaseous film itself. In twin-belt machines, relative heat-transfer rates into upper and lower belts are controlled by adjusting the relative helium percentages in their respective gas films.

Belt composition for improving performance and flatness of thin

Method and belt composition for improving performance and flatness in

A method and system are provided for synchronizing the travelling edge dams in the continuous casting of metal slab, strip, or bar, thereby providing a means for the continuous uniform casting of longitudinally spaced edge shapes, contours, or profiles such as integral shoulders, lugs, lobes, depressions, curves, or indentations in the opposite edges of the cast product. Shapes include the protruding lugs, cast directly opposite each other, for suspending copper anodes in electrolytic refining-also the intruding, material-saving contours in the tops of anodes. A belt-type continuous casting machine is shown wherein two moving contoured edge dam loops each comprise blocks strung upon flexible endless metal straps. The moving edge dams on each side of the mold must be synchronized, regardless of disturbing thermal variations notably. 'Back breakers' exert upward rolling contact force controllably and separately against each moving edge dam loop along its return path, thereby changing the local curvature and so adjusting the degree of mutual compression and closeness of the constituent dam blocks or the end-to-end spacing of the same. Such compression effectively shortens the elevated edge dam loop and thereby hastens its revolutions. Known previous methods of heating or cooling to synchronize the edge dam loops may advantageously be used in addition to back-breaker control. The positioning of separate 'back-breaker' apparatus in an inverted configuration near the entrance to the moving mold results in a significant improvement in the sealing capability of the entering edge dams against the lower casting belt where molten metal is introduced.

Edge dam synchronization and tensioning control method and system for

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Colchester, VT, United States of America

Jerome B Allyn