Effect of Concentration of Gas-Generating Agent on Regularities of Development Fireproofing Foamed Cokes
In this paper results of studying are stated by thermometry methods, thermogravimetry, the differential scanning analysis of features of behaviour of the gas-forming agent (melamine) in a wide range of concentration in phosphate-ammonium spirit compositions in the presence of high-molecular hydrogen and in its absence. It is shown, what besides well-known function of the gas-forming agent melamine also provides "Stephan" character of movement endothermic front of transformations through thickness of a coating. In addition, products of the melamine decomposition directly participates in "building" of coke and in development of thermal oxidation in the presence of high-molecular hydrocarbon.With concentration of the melamine growth in the studied range of concentration such properties of compositions as the foaming factor, limiting time of heating of a steel substratum under foaming coatings will change on s-shaped curves. That is it is possible to speak about two critical melamine concentrations. In a range of concentration between these critical concentration considerable change of properties foamed coke takes place. Below the first critical concentration change of properties is not enough. Above the second critical melamine concentration in foaming, coked structure foaming factor, thermal resistance of coke practically cease to increase that can be connected with removal from system of gaseous products which are superfluous and cannot be absorbed system, number and size of defects of foamed coke increases.