Combustion in a Cold Blast Cupola

Abstract

Cupola melting is primarily combustion/gasification of a coke bed containing a high inert of which some fraction melts continuously. The data base on such systems is sparse. So far base line experiments have been carried out without melting. In the present study, detailed experimental investigations were carried out on a 200 mm diameter cupola with and without melting of metal. The study of the distribution of temperature and the concentrations of the products of combustion at different points in the cupola in the two cases (i.e., with and without melting of metal) has revealed that the combustion (oxidation) as well as gasification (reduction) reactions are intensified right from the luyere level in the combustion zone. when melting of metal occurs on a thick coke bed and the superheated molten metal trickles down the bed. The carbon precipithick tation reaction is catalyzed by the solid cast-iron charge at elevated temperature in the melting zone and above it. The zone of negligible oxygen concentration (ZNO2) and the zone of maximum carbon dioxide (ZMCO2) and the zone of maximum temperature (ZMT) appear at lower heights, when the metal is melted and also the ZMCO2 and ZMT do not coincide as in the case of combustion of coke alone. The temperatures of gases at all the points in the regions above the melting zone and also in the ZMT are reduced. The temperature of gases at all the points in the regions below the melting zone are found to be higher. The melting rate and the molten metal temperature at the spout are observed to be a direct linear function of the combustion efficiency ratio (π_c). the relative carbon saturation (RCS), and the temperature of the gases (T_g) at the periphery within the melting zone, just above the initial coke-bed height.