GB801547A - Improvements relating to continuous casting machines - Google Patents

Abstract

801,547. Automatic fluid level control systems. PROPERZI, I. Dec. 16, 1955 [Dec. 31, 1954], No. 36195/55. Class 38 (4). In a system for automatically controlling the level of the surface of molten metal in a continuous casting machine the mould is formed by a channel round the circumference of a rotating wheel and a strip of material wrapped round a portion of the circumference, and changes in temperature of liquid sprayed on the outside of the strip are utilized to control the speed of the wheel through an electric control system. In Fig. 2 a continuous casting mould, e.g. for aluminium bar, is formed between a channel round the circumference of a rotating wheel 12 and a strip 32 which meets the wheel tangentially and encloses a portion of the circumference. The molten metal is supplied through a nozzle 31 and the wheel is rotated at such a speed that the level of the molten metal remains approximately at the point where strip 32 meets wheel 12. The level of molten metal is detected by spraying fluid from a conduit 33 on to the outside of strip 31 and arranging two thermocouples 20, 21 or alternatively two temperature-variable resistors so that one of them is associated with boiling fluid and the other is not when the level is correct. Deviation of the level from the desired position affects the relative temperatures of the thermocouples or temperaturevariable resistors and a potentiometer (not shown) is arranged to be set automatically to a corresponding position. This potentiometer is associated with limit switches which when operated start an electric motor to maintain the level of molten metal between limits by adjusting a variable-speed gear in the drive to wheel 12. A clutch is provided between the motor and variable-speed gear to permit manual adjustment of the latter.