Kiln Degradation Control by Design and Operation Measures

The walls of industrial structures subject to high internal temperatures are constructed of multiple layers to provide fire protection, temperature insulation, and the necessary structural strength. In industrial ovens the interior brick layer provides a fire‐resistant barrier and the external steel shell provides structural integrity. An intermediate insulation layer protects the exterior shell from excessive heat and controls heat loss during operations. Crushing, spalling, and cracking of the brick layer result in relatively frequent major maintenance efforts and costly loss of production time. Oversimplifications in system analysis and design misrepresent these maintenance demands as unavoidable. The problem requires indepth understanding of the strain and stress development under transient and stationary temperature‐loading conditions. A systematic analytical approach to the behavior of individual layers of an oven‐wall structure is presented. Conditions that can lead to brick destruction or even to cyclic yielding and failure of the steel shell are defined. Calculation procedures are presented for determining permissible rates of temperature change and evaluating the usefulness of gaps constructed behind the interior brick lining.