The Babcock & Wilcox Company

Other

Innerspec Technologies, Inc

Jonathan D Buttram

John H Flora

Wayne M Latham

William E Lawrie

Daniel M Schlader

A method and apparatus for simultaneously inspecting and grinding roll mills which utilizes a transducer assembly which produces a creeping wave propagation in conjunction with a couplant fluid provider and data acquisition circuit which allows the operator to see the crack and imperfections in on the surface of the mill rolls as they are rotated and to grind them off.

Creeping wave technique for mill roll inspection

An improved high temperature electromagnetic acoustic transducer (EMAT) for conducting inspections of materials with elevated temperatures, which has cooling means using gas cooling, such as air or nitrogen, for cooling the transducer RF coil, the onboard circuitry and magnets, while also providing for the easy removal of the coil and onboard circuitry. Prior art EMAT's are susceptible to failure since high temperatures reduces the signal quality of the electronics components, degrades the insulation of the RF coils, and permanent magnets can loose field strength.

High temperature electromagnetic acoustic transducer

A method of examining a ductile iron casting to determine a percent of nodularity present in the casting uses an electromagnetic acoustic transducer (EMAT) system to determine a time-of-flight of an ultrasonic shear wave pulse transmitted through the casting at a selected location, from which a velocity of sound in the casting can be determined. The ultrasonic shear wave pulse created and sent through the casting experiences several internal reflections within the casting, and the absolute delay time for both second, T.sub.DELAY1, and third, T.sub.DELAY2, multiple reflections are used to determine the time, T.sub.DELTA, required for the ultrasonic pulse to travel through twice the thickness, t, of the casting at said location. The velocity, V.sub.SHEAR, of the ultrasonic shear wave pulse through the casting is calculated from T.sub.DELTA and a measurement of the thickness, t, of the casting at the location being inspected. The percent of nodularity of the casting is determined from a pre-established relationship between the calculated shear wave velocity, V.sub.SHEAR, and the percent of nodularity for ductile cast iron.

EMAT measurement of ductile cast iron nodularity

The presence of a crack in a material and the orientation of the crack is determined by placing a transducer on the surface of the material for propagating a shear wave for reflection off of the back wall of the material. The reflected signal is evaluated such that no signal or a weak signal indicates the presence of a crack. The transducer is then held in place and rotated while propagating a shear wave in order to determine the orientation of the crack. The reflected shear wave is then evaluated in the same manner.

Crack orientation determination and detection using horizontally

A method of determining low density deposits on the inner surface of a boiler tube comprises the generation of ultrasonic energy which is directed from the outer surface of the tube to the inner surface of the tube. The energy is reflected back and forth between the inner and outer surfaces with each reflection of the inner surface loosing energy by attenuation into any existing low density deposit. The first and fourth reflections are measured and digitized for analysis to determine the amount of attenuation. The amount of attenuation is representative of the low density deposit on the inner surface of the tube. The tube is preferably empty of water to avoid transmission of ultrasonic energy through water in the tube.

Growing community of inventors

Bedford, VA, United States of America

Jonathan D Buttram