Combustion of Carbon in Casting Powder in a Temperature Gradient

Abstract

The combustion of carbon in a packing of casting powder has been investigated in an apparatus simulating the thermal conditions in the continuous casting mold. The temperature gradient was established along the powder column and air was admitted at its cold upper surface. After the reaction time the column was cooled to room temperature and the carbon profile was determined. The results show a strong variation of carbon content along the column with the original content still existing at the top, a pronounced carbon minimum in the middle and a second minimum at the bottom. A mathematical model was developed for the theoretical investigation of the combustion problem. It involves the solution of the rate equations for the chemical reactions and of the differential equations for heat flow, transport of gaseous species and continuity. The model produces carbon profiles in the packing and off-gas compositions which agree satisfactorily with those measured.