Diagnostic Tools for Yankee Dryers, 2000 Engineering Conference Proceedings

John A. Charles, Ph.D.--Operating problems in Yankee cylinders stem from many sources including dryer thermal anomalies, surface irregularities, chemical spray system issues, and other influences. When left unsolved, these problems can result in machine runnability issues including sheet breaks, sheet blistering, crepe blade wear, and excessive machine down time. Moreover, poor product quality and converting difficulties can also be associated with Yankee dryer problems. The correct and timely diagnosis of Yankee problems is therefore critical to the overall productivity of tissue and towel paper machines.

Among the many diagnostic tools available to help solve Yankee dryer problems, two techniques which are highly effective in assessing the operating condition of the Yankee dryer are Precision Infrared Thermography (PIR) and Operating Surface Topography (OST) measurements. When used separately, PIR and OST measurements each provide valuable information to the diagnostic engineer. When applied together, however, PIR and OST techniques complement each other and yield a more complete analysis of the Yankee problem.

This paper discusses precision infrared thermography and operating surface topography and their relationship in solving Yankee dryer operating problems. An example of their application is presented which illustrates the synergy of IR and OST techniques in correctly diagnosing a Yankee dryer problem.