Analytical Model of Absorption-Reflection Properties of Vermiculite Under Thermal Radiation Conditions

Abstract

Amethod for determining the absorption-reflection properties of a single grain of vermiculite and a dense single-layer array of intumescent vermiculite located on a planar surface under thermal radiation is considered. Based on the experimental graph of dehydration, the whole process of calcination and mechanical transformation of vermiculite can be broken down into stages. For each stage the averaged reflection and absorption coefficients are determined based on the idealized notion that the lateral faces of the grains due to the scaly structure completely absorb radiant energy of the heating elements, and the end faces completely reflect it. Based on the weighted average optical coefficients for a single grain and a single-layer array as a whole throughout the entire heat treatment period, a finite static optical model of the array was constructed.