Metodologia para previsão de vida útil de âncoras cerâmicas aplicadas em fornos de reaquecimento

Abstract

The use of ultrasound technique in evaluation, selection and classification of ceramic anchors applied to the ceiling and walls of reheating furnaces allows identifying the main defects and also determining their thermal shock resistance due to the alteration of the modulus of elasticity with the number of thermal cycles applied to the material. The typical thermal shock resistance of new anchors that meet all technical specifications is approximately 29 cycles, and these materials have a history of service life of about 15 years for walls and 10 years for the roof. The degradation of the elastic modulus and thermal shock resistance of these parts throughout its life allows predicting the life expectancy of the refractory lining mounted with these materials. With these results, one can compare the "real age", identified by this methodology, with the "chronological age" which considers the operating time of the refractory lining. It can still, as a result, estimate the time to failure of these refractory parts, improve the planning of the charts of these furnaces for maintenance and avoid unplanned shutdowns, which would cause loss of production and damage to businesses.