The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 2002
Filed:
Aug. 31, 2000
Anders Lehman, Bromma, SE;
ABB AB, Vasteras, SE;
Abstract
A method and a device for continuous or semi-continuous casting of metal, where hot melt is supplied to a cooled continuous casting mold and the melt is cooled and formed to a at least partly solidified strand as it passes through the mold. An inductive coil is arranged at the top end of the mold to, when supplied with an alternating electric high frequency current, generate a high frequency magnetic field to act upon the melt in the mold, whereby heat is developed in the melt and compressive forces acting to separate the melt from the mold wall are generated. The coil is supplied with the high frequency current from a power supply unit with a current control to supply an alternating electric high frequency current having a base frequency of 50 Hz or more to the inductive coil. The current control has modulation means for modulating and controlling the supplied current is controlled in a pulsed, amplitude modulated manner with an amplitude modulated modulation frequency of 10 Hz. or less, whereby essentially full amplitude of the amplitude modulated current is achieved within a rise time corresponding to 1 cycle of the base frequency or less at the start of a pulse.