Apparatus for detecting onset of slag entrainment in a molten metal stream
US4859940A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1987 |
| Grant date | Aug 22, 1989 |
| Priority date | — |
| Expiry date | Sep 9, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/2025
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A slag detector apparatus for detecting onset of 5% or less slag entrainment in a stream of molten metal employs a detection coil having an axial length at least equal to the length of a globule of molten metal in the stream being composed of a continuous succession of recurring cyclical globules of molten metal, and an impedance detector for periodic sampling and smoothing of the fluctuations of the terminal impedance of the detector coil corresponding to the fluctuating cross-sectional dimension of the stream. The detector coil is part of a signal sensitivity enhancement circuit in the apparatus which also includes a tunable capacitor connected with the detector coil. The capacitor is used for tuning the circuit to its resonance frequency so that the capacitive reactance of the circuit due to the presence of the capacitor cancels the inductive reactance of the circuit due to the presence of the coil so as to leave only an impedance that is due to resistance of the coil.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.