Apparatus and method of ultra rapid annealing by induction heating of thin steel strip
US5214258A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 1, 1991 |
| Grant date | May 25, 1993 |
| Priority date | — |
| Expiry date | Feb 1, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/25
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
An induction heating apparatus and method for ultra rapid annealing of a ferromagnetic strip moving at a selected velocity along a given path. The apparatus and method uses a vacuum tube R.F. oscillator having a D.C. input power supply providing D.C. voltage and D.C. current to the oscillator, a grid, a radio frequency output, and a grid feedback circuit for driving the grid. An induction heating coil surrounds the strip, and a known length along the path. A parallel capacitor bank forms the coil into a main tank circuit with a resonant frequency. Means are provided for sensing the voltage of the induction heating coil and for adjusting said D.C. voltage of the input power supply in accordance with said sensed coil voltage to maintain the power density in the strip at a selected level as the strip passes through the coil to raise the temperature of the moving strip at a rate sufficiently high to exceed the Curie point temperature of the moving strip.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.