Gary E Thornton

US Patent:

20160231266, Aug 11, 2016

Filed:

Apr 15, 2016

Appl. No.:

15/130530

Inventors:

- ATLANTA GA, US
GARY THORNTON - FORT COLLINS CO, US

Assignee:

NOVELIS INC. - ATLANTA GA

International Classification:

G01N 27/07
G01N 33/20

Abstract:

Methods and apparatus for measuring the cleanliness of molten metals. Direct current is passed between electrodes through molten metal advancing through a passage in an electrically resistive wall. A voltage signal is analyzed for the presence of solid generally non-metallic inclusions in the metal. Direct current is supplied by one or more ultra-capacitors and the decay in discharge voltage of the capacitor(s) is compensated for by passing the current from each capacitor through a resistor ladder network circuit having resistors connected in parallel. Individual resistors are switched on or off in a sequence effective to change the resistance of the circuit and maintain the current within a predetermined range. Heat generation and noise pick-up are minimized by maintaining a low discharge voltage and measurement current while using FETs only in the fully ON or OFF conditions to switch the resistors into or out of the circuits.

US Patent:

20140266150, Sep 18, 2014

Filed:

Mar 10, 2014

Appl. No.:

14/203257

Inventors:

- ATLANTA GA, US
GARY THORNTON - FORT COLLINS CO, US

Assignee:

NOVELIS INC. - ATLANTA GA

International Classification:

G01N 27/00

US Classification:

324 711

Abstract:

Methods and apparatus for measuring the cleanliness of molten metals. Direct current is passed between electrodes through molten metal advancing through a passage in an electrically resistive wall. A voltage signal is analyzed for the presence of solid generally non-metallic inclusions in the metal. Direct current is supplied by one or more ultra-capacitors and the decay in discharge voltage of the capacitor(s) is compensated for by passing the current from each capacitor through a resistor ladder network circuit having resistors connected in parallel. Individual resistors are switched on or off in a sequence effective to change the resistance of the circuit and maintain the current within a predetermined range. Heat generation and noise pick-up are minimized by maintaining a low discharge voltage and measurement current while using FETs only in the fully ON or OFF conditions to switch the resistors into or out of the circuits.

US Patent:

20140266316, Sep 18, 2014

Filed:

Mar 10, 2014

Appl. No.:

14/203335

Inventors:

- ATLANTA GA, US
GARY THORNTON - FORT COLLINS CO, US

Assignee:

NOVELIS INC. - ATLANTA GA

International Classification:

H03K 5/125
G01N 27/07

US Classification:

327 91

Abstract:

Methods and apparatus for measuring the cleanliness of molten metal. Direct current is passed through molten metal advancing through a passage. A voltage signal is analyzed for the presence of solid generally non-metallic inclusions in the metal. A method includes sampling digital data of the voltage signal to generate data samples; updating a delayed running average of the data samples to establish a baseline for identifying sudden changes in amplitude of the data samples; determining a threshold by adding a prescribed value to the baseline; identifying a possible inclusion when a significant number of data samples exceeds the threshold; storing a maximum count as the data samples using peak detection until a prescribed number of the data samples fall below the threshold; and comparing a parameter of the possible inclusion with a lookup table to categorize the possible inclusion as either (i) an actual inclusion or (ii) noise.