Abstract: Twin roll casting method and apparatus in which molten metal is introduced between a pair of chilled rolls (16) via an elongate delivery nozzle (19) to form a casting pool (68) above the nip (69) between the rolls (16). Rolls (16) are rotated to cast a solidified strip (20) delivered downwardly from the nip (69). Delivery nozzle (19) comprises upwardly opening trough having side walls (62), a floor (63) and bottom outlet openings (64). A pair of upright flow barrier walls (84) stand up from floor (63) to define an internal trough channel (85) to receive the incoming flow of molten metal (65). Barrier walls (84) prevent direct flow of the incoming metal to the outlet openings (64).

Abstract: Continuous casting of steel strip in twin-roll caster comprises casting rolls (16). Molten steel is delivered by a delivery system and comprising delivery nozzle (19b) to casting pool (30) supported above nip (10) between the casting rolls (16) which are rotated to deliver a solidified strip (20) downwardly from the nip. To avoid dissolution of carbon from refractories of the metal delivery system including the nozzle (19b), the molten steel is a silicon/manganese killed carbon steel having a manganese content of not less than 0.02% by weight, a silicon content of not less than 0.10% by weight, an aluminium content of less than 0.01% by weight and a sulphur content of at least 0.02% by weight. The required sulphur content of the steel may be achieved by addition of iron sulphide to a batch of steel in a tundish (18) of the delivery system.

Abstract: There is provided a structure for joining an impeller to a rotatable shaft, including (a) a bushing through which the impeller is joined to the rotatable shaft, the bushing including a hollow cylindrical portion which is to fit into a recess formed with the impeller and into which the rotatable shaft is to fit, (b) a first joint structure for joining the bushing to the impeller so that the bushing is positioned coaxially with the impeller, and (c) a second joint structure for joining the rotatable shaft to the bushing so that the rotatable shaft is positioned coaxially with the bushing. The structure provides a sufficient ability for transferring a torque between an impeller and a shaft, self-aligning performance between an impeller and a shaft, and good serviceability for assembling and disassembling, and further provides higher accuracy in axially positioning an impeller and a shaft and lower fabrication costs.