Condition based monitoring — Kiln and ball mill girth gear audit

This practice describes a two-part, new proposed standard for electromagnetic methods for preparation and examination of gear teeth in the cement sector on kiln and ball mill girth gear drives, including pinions - particularly on the addendum, dedendum, and root areas. This practice addresses the need to detect surface breaking flaws electronically and to have the ability to accurately size any surface breaking cracks found on cast and forged kiln or ball mill girth gear and pinion teeth faster and more effectively than other methods. Eddy-current surface arrays are seeing increasing use throughout the industry for the detection of surface breaking flaws in conducting materials. Example applications include examinations of pipelines, bridges, engines, aerospace structures, and any conducting material for surface breaking flaws including cracks. In addition, model-based methods are being used to size cracks accurately found in the addendum, dedendum, and the root of kiln and ball mill girth gear teeth. As visual interpretation of a surface breaking discontinuity on gear teeth is the normal analysis, the colors and 3D images that are provided with this technique, help with visualization and therefore are absolutely invaluable in such circumstances. This practice will help to standardize the use of this nondestructive testing approach.