Arc voltage distribution skewness as an indicator of electrode gap during vacuum arc remelting
AssigneeSandia Corporation
InventorsRodney L. Williamson, Frank J. Zanner, Stephen M. Grose
Life of this patent
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Abstract
The electrode gap of a VAR is monitored by determining the skewness of a distribution of gap voltage measurements. A decrease in skewness indicates an increase in gap and may be used to control the gap.
Claims16
A method for controlling electrode gap width in a vacuum arc remelting furnace having an electrode spaced across an adjustable gap from an electrically conductive surface, and a direct current power source causing an electric arc across the gap, an electrode gap voltage being formed between the electrode and the surface, the method comprising the steps of:
- a) determining an arc voltage distribution skewness of the electrode gap voltage;
- and
- b) controlling the gap based on changes in the skewness.
An apparatus for controlling electrode gap width in a vacuum arc remelting furnace having an electrode spaced across an adjustable gap from an electrically conductive surface, and a direct current power source causing an electric arc across the gap, an electrode gap voltage being formed between the electrode and the surface, the apparatus comprising:
- means for determining an arc voltage distribution skewness of the electrode gap voltage;
- and
- means for controlling the gap based on changes in the skewness.
Dependencies are inferred from the claim text.