Acoustic Emission Testing of Paper Machine Dryers - Effects of Thermal Simulation, 2004 11th International Symposium on Corrosion in Pulp and Paper Industry
Building on an earlier TAPPI-funded study on suitability of acoustic emission testing (AET) for inspecting Yankee
dryers and similar materials and construction in regular paper machine dryer cans, AET is increasingly being
considered as an advantageous way to inspect regular and Yankee dryers. AET requires physical stimulation of
discontinuities to detect them and normally this is done by pressurizing the dryer can. However, many mills have
problems getting the dryer pressure 5% above the highest pressure it has seen in the previous six months as
stipulated in the standard AET procedure.
One way to overcome this difficulty is to stimulate the emissions with thermal stresses arising during dryer heating
and cooling. This paper discusses why thermal stimulation should be as effective as pressure stimulation for AET
of a paper machine dryer and the basic way of conducting the test.
Acoustic Emission Testing of Paper Machine Dryers - Effects of Thermal Simulation, 2004 11th Interna