Hazelett Strip-casting Corporation

Robert William Hazelett

John F Wood

John M Dompas

Robert J Carmichael

Stanley W Platek

Charles J Petry

Samuel R Hazelett

Methods for continuously casting metal product directly from molten metal confined and solidified in a casting region defined by upper and lower, cooled, endless, flexible, traveling, casting belts supported by belt support systems including back-up rollers in respective upper and lower carriages and laterally defined by first and second traveling side dams. The back-up rollers and belt support systems shape and maintain the casting region for improved heat transfer between cast metal and belts for improved product uniformity and enhanced machine performance. Several methods are disclosed including having one belt flexibly constrained, resulting in a transverse bowing away from the casting centerline due to liquid metal head, with the opposing belt being rigidly constrained and contoured or transversely bowed towards the casting centerline in a configuration that compensates for displacement of the flexibly constrained belt resulting in a uniform transverse cross section. Methods are disclosed including bowing the upper back-up rollers down either by manual adjustment or remote control and at the same time allowing the lower rollers to yield; intentionally rigidizing the upper and/or lower back-up rollers or sections thereof; bowing both sets of back-up rollers in equal and opposite directions, bowing the rollers inward or outward using either manual adjustment or remote control tensioning; bending structural frame members which are in support relationship with rollers, thus maintaining predetermined configurations of rollers in contact with the belts and further including downstream tapering of the casing region.

Methods for shaping the casting region in a twin-belt continuous casting

Systems are provided for continuously casting metal product directly from molten metal confined and solidified in a casting region defined by upper and lower, cooled, endless, flexible, traveling, casting belts supported by belt support systems including back-up rollers in respective upper and lower carriages and laterally defined by first and second traveling side dams. The back-up rollers and belt support systems shape and maintain the casting region for improved heat transfer between cast metal and belts for improved product uniformity and enhanced machine performance. Several systems are disclosed including having one belt flexibly constrained, resulting in a transverse bowing away from the casting centerline due to liquid metal head, with the opposing belt being rigidly constrained and contoured or transversely bowed towards the casting centerline in a configuration that compensates for displacement of the flexibly constrained belt resulting in a uniform transverse cross section. Systems are disclosed including bowing the upper back-up rollers down either by manual adjustment or remote control and at the same time allowing the lower rollers to yield; intentionally rigidizing the upper and/or lower back-up rollers or sections thereof; bowing both sets of back-up rollers in equal and opposite directions, bowing the rollers inward or outward using either manual adjustment or remote control tensioning; bending structural frame members which are in support relationship with rollers, thus maintaining predetermined configurations of rollers in contact with the belts and further including downstream tapering of the casting region.

Systems for shaping the casting region in a twin-belt continuous casting

Methods and apparatus for feeding and continuously casting molten metal are described in which inert gas is applied to the moving mold surfaces and to the entering metal for the protection or shrouding of the molten metal surface within the mold cavity from oxygen and other detrimental atmospheric gases. The shrouding is by means of inert gas injected into the mold through a semi-sealing nosepiece, or directed at the mold cavity and passing through the necessary slight gaps around the nosepiece. At the same time, such inert gas is further circulated by channeling or shielding the circulated gas for blanketing and diffusing of the inert gas along the moving mold surfaces for cleansing them of undesired accompanying gases, such as atmospheric oxygen, water vapor, sulphur dioxide, carbonic acid gas, etc. as the mold surfaces approach the nosepiece before entering the mold region. In installations where the inert gas is directed at the mold cavity from above and/or below the nosepiece, the gas is ejected at a relatively slow flow rate so as to be noiselessly ejected, i.e. without audible disturbance, the objective being to avoid entrainment of air. Heavier-than-air inert gas may advantageously be used above the nosepiece, while lighter-than-air inert gas is simultaneously used below it.

Method and apparatus for feeding and continuously casting molten metal

Apparatus for feeding and continuously casting molten metal is described in which inert gas is applied to the moving mold surfaces and to the entering metal for the protection or shrouding of the molten metal surface within the mold cavity from oxygen and other detrimental atmospheric gases. The shrouding is by means of inert gas injected into the mold through a semi-sealing nosepiece, or directed at the mold cavity and passing through the necessary slight gaps around the nosepiece. At the same time, such inert gas is further circulated by channeling or shielding the circulated gas for blanketing and diffusing of the inert gas along the moving mold surfaces for cleansing them of undesired accompanying gases, such as atmospheric oxygen, water vapor, sulphur dioxide, carbonic acid gas, etc. as the mold surfaces approach the nosepiece before entering the mold region. In installations where the inert gas is directed at the mold cavity from above and/or below the nosepiece, the gas is ejected at a relatively slow flow rate so as to be noiselessly ejected, i.e. without audible disturbance, the objective being to avoid entrainment of air. Heavier-than-air inert gas may advantageously be used above the nosepiece, while lighter-than-air inert gas is simultaneously used below it.

Apparatus for feeding and continuously casting molten metal with inert

The casting belt is preheated with steam closely ahead of the entrance to the casting zone by providing wrap-around steam feed tubes having nozzles, such tubes being positioned in very deep circumferential grooves in input pulley or nip pulley which moves the casting belt into the input end of the casting zone. These circumferential grooves of the input or nip pulley also house wrap-around liquid coolant feed tubes for cooling the casting belt near the beginning of the casting zone. The wrap-around steam feed tubes also have radial ports positioned to direct steam toward the reverse side of the endless belt, with the port being spaced from the nozzle thereby providing a staged elevation of temperature in the flexible casting belt on the input or nip pulley, while the belt is in contact therewith before the belt reaches the casting zone. Elevating the temperature prior to the endless belt reaching the casting zone and then suddenly cooling the belt when the molten metal is applied thereto improves casting conditions in the operation of such thin, flexible casting belt and enhances and speeds up the casting process. There are several ways for preventing coolant water from cooling the steam header and tubes of the bottom nip pulley in a twin-belt machine.

Method of and apparatus for steam preheating endless flexible casting

Improved casting method and side dam apparatus for use in twin-belt continuous metal casting machines are described particularly adapted for casting rectangular copper bar providing a casting speed almost double that obtained in prior twin-belt machines and a damblock lifetime which is more than doubled, while producing a more homogeneous and symmetrical casting structure. The side dams are formed by stringing slotted damblocks along the entire length of a flexible metal strap, except for end portions of the strap. An end-to-end weld forms an endless strap loop of accurately predetermined length, and special damblocks having two mating interlocking halves are inserted into the remaining space along the strap, whereby all blocks are free to slide on the strap but with little cumulative space between blocks, which are preferably made of a bronze alloy presenting better resistance to heat cracking and higher heat conductivity than in previous damblocks. The damblocks are cooled by controlled liquid sprays in a chamber, their temperature after cooling is sensed, and then they have an insulative material applied thereto before re-entry into the machine.

Method and apparatus for continuously casting copper bar product

Method and apparatus are described for continuously casting metal slab, strip or bar with integral lugs projecting therefrom. These lugs project from the edge of the cast product and lie in the casting plane, but they have a partial thickness as compared with the thickness of the product. Continuous wide slabs of unrefined copper or other electrolytically refinable metal having partial thickness lugs on both edges can be cut to form electrode plates for subsequent refining by suspending in an electrolytic bath. These partial thickness lugs serve as supports and provide electrical connection from the side rails of the electrolytic cell. Their partial thickness conserves metal and weight. In the continuous casting method and apparatus the revolving edge dams include special dam blocks defining partial thickness mold pockets for casting the integral lugs. Synchronization of lug positions along opposite edges of the cast product is maintained by controllably changing the relative temperatures of the revolving edge dams with respect to each other, for example, by relatively increasing the cooling of one of the revolving edge dams when it tends to lag the other, thereby relatively decreasing its length and increasing its rate of revolving, or, for example, by relatively decreasing the cooling of one when it tends to lead the other, thereby relatively increasing its length and decreasing its rate of revolving.

Method and apparatus for continuously casting metal slab, strip or bar

Continuous casting apparatus is described wherein the temperature of the flexible casting belts in twin-belt machines having two or more main rolls in each belt carriage is controllably elevated prior to contact with the molten metal to improve the casting conditions and the operation of the thin flexible casting belts; the temperature elevation preferably being relatively gradual may be carried out while the travelling belts are approaching the nip rolls or while the belts are in contact with the nip rolls, or both. Zone control of belt pre-heating is disclosed, and control of the coolant streams issuing from the curved nip roll tubes by use of fingernail-like extenders may be provided to aid in pre-heating the belts and in controlling their operation. Intensive infra-red heaters are shown directed at close range toward the casting surfaces of the belts, these heaters serving also to cure and dry any coating material on the belts. Heating of the nip rolls by means of hot fluid, such as steam, is described, with the hot fluid being directed into the interior of the nip roll or being directed into the deep grooves in the nip roll beneath the rear surfaces of the casting belts. Mechanical and thermal sensors may be employed to sense the distortion of the belts and to measure their operating temperatures, these sensors being shown with automatic control of the belt pre-heating action. The apparatus of the invention can be applied to twin-belt casting machines regardless of whether the molten metal is supplied by open pool, closed pool or injection feeding.

Coolant nozzle apparatus in twin-belt continuous casting machines

Continuous casting methods and apparatus are described wherein the flexible casting belts in twin-belt machines having two or more main rolls in each belt carriage are sensed by mechanical probes, and belt temperatures are controllably elevated prior to contact with the molten metal to improve the casting conditions and the operation of the thin flexible casting belts; the temperature elevation preferably being relatively gradual may be carried out while the travelling belts are approaching the nip rolls or while the belts are in contact with the nip rolls, or both. Zone control of belt pre-heating is disclosed, and control of the coolant streams issuing from the curved nip roll tubes by use of fingernail-like extenders may be provided to aid in pre-heating the belts and in controlling their operation. Intensive infra-red heaters are shown directed at close range toward the casting surfaces of the belts, these heaters serving also to cure and dry any coating material on the belts. Heating by means of hot fluid, such as steam, is described, with the hot fluid being directed into the deep grooves in the nip roll beneath the rear surfaces of the casting belts. Mechanical and thermal sensors are employed to sense the distortion of the belts and to measure their operating temperatures, these sensors being shown with automatic control of the belt pre-heating action. The methods and apparatus of the invention can be applied to twin-belt casting machines regardless of whether the molten metal is supplied by open pool, closed pool or injection feeding.

Twin-belt continuous casting wherein the belts are sensed by mechanical

Continuous casting apparatus wherein the temperature of the flexible

A symmetrical belt-steering and tensioning system and apparatus for twin-belt continuous metal casting machines are disclosed. A rigid squaring shaft passes through a hollow tension and steering roll and is rigidly secured to torque arms at opposite ends of the roll assuring that this roll remains parallel with the driving roll at the other end of the carriage throughout the range of tensioning travel, these arms each being associated with tension thrust means and steering means. The geometrical relationships assure that tension in the casting belts remains essentially directly proportional to the fluid pressure in the thrust cylinders, while a pre-loading arrangement removes back lash from the pivots to improve steering precision and also provides mechanical advantage. A symmetrical synchronized steering action is applied to both ends of the tension-steering roll, and axial thrust control means operate to force the roll skewing movement to center at a predetermined point. Independent adjustment of the displacement of each end of the tension-steering roll from the pass line is provided by sleeves associated with the squaring shaft and bearings in the interior of the hollow roll. A high belt tension force can be applied because there are two main large diameter rolls at opposite ends of each carriage defining the belt path as a symmetrical oval shape. Wide casting belts of 116 inches in width or more are precisely steered and tensioned for continuously casting slabs 100 inches or more in width.

Symmetrical synchronized belt-steering system and apparatus for

Improved casting side dam apparatus for use in twin-belt continuous metal casting machines is described particularly adapted for casting rectangular copper bar providing a casting speed almost double that obtained in prior twin-belt machines and a damblock lifetime which is more than doubled, while producing a more homogeneous and symmetrical casting structure. The side dams are formed by stringing slotted damblocks along the entire length of a flexible metal strap, except for end portions of the strap. An end-to-end weld forms an endless strap loop of accurately predetermined length, and special damblocks having two mating interlocking halves are inserted into the remaining space along the strap, whereby all blocks are free to slide on the strap but with little cumulative space between blocks, which are preferably made of a bronze alloy presenting better resistance to heat cracking and higher heat conductivity than in previous damblocks. During return travel from the output end of the machine to the input, the side dams are passed by tension apparatus which deflects them along a smoothly curved arc convex toward the interior of the side dam loop to take up any available slack, forcing the blocks tightly together in end abutting relationship along the casting zone, thus ensuring a cast product without burrs on the side surfaces. The damblocks are cooled by liquid sprays before re-entry into the machine.

Twin-belt continuous casting apparatus

A symmetrical belt tensioning system and apparatus for twin-belt continuous casting machines are disclosed. A rigid squaring shaft passes through a hollow tension roll and is rigidly secured to torque arms at opposite ends of the roll assuring that this roll remains parallel with the driving roll at the other end of the carriage throughout the range of tensioning travel, these arms each being associated with tension thrust means. The geometrical relationships assure that tension in the casting belts remains essentially directly proportional to the fluid pressure in the thrust cylinders, while a pre-loading arrangement removes back lash from the pivots to improve steering precision and also provides mechanical advantage. Independent adjustment of the displacement of each end of the tension-steering roll from the pass line is provided by sleeves associated with the squaring shaft and bearings in the interior of the hollow roll. A high belt tension force can be applied because there are two main large diameter rolls at opposite ends of each carriage defining the belt path as a symmetrical oval shape. Wide casting belts of 116 inches in width or more are precisely steered and tensioned for continuously casting slabs 100 inches or more in width.

Symmetrical belt tensioning system and apparatus for twin-belt

Continuous casting methods are described wherein the temperature of the flexible casting belts in twin-belt machines having two or more main rolls in each belt carriage is controllably elevated prior to contact with the molten metal to improve the casting conditions and the operation of the thin flexible casting belts; the temperature elevation preferably being relatively gradual may be carried out while the travelling belts are approaching the nip rolls or while the belts are in contact with the nip rolls, or both. Zone control of belt pre-heating is disclosed, and control of the coolant streams issuing from the curved nip roll tubes by use of fingernail-like extenders may be provided to aid in pre-heating the belts and in controlling their operation. Intensive infra-red heaters are shown directed at close range toward the casting surfaces of the belts, these heaters serving also to cure and dry any coating material on the belts. Heating by means of hot fluid, such as steam, is described, with the hot fluid being directed into the deep grooves in the nip roll beneath the rear surfaces of the casting belts. Mechanical and thermal sensors may be employed to sense the distortion of the belts and to measure their operating temperatures, these sensors being shown with automatic control of the belt pre-heating action. The methods of the invention can be applied to twin-belt casting machines regardless of whether the molten metal is supplied by open pool, closed pool or injection feeding.

Growing community of inventors

Winooski, VT, United States of America

Robert William Hazelett