Physical Model of Influence of CaO–FeO–SiO2 Powder Fraction on the Heat Transfer from Torch

Abstract

Introduction. One of the main ways of heat transfer in metallurgical units is the interaction of the charge with a burning gas torch. The heat is transferred from the torch mainly by radiation. In particular, oxygen converter process under its typical temperature and chemical conditions of oxidation processes is accompanied by combustion reactions with the formation of a torch both in the cavity of the converter (in the so called reaction zone) and above the converter neck as a result of partial post-combustion of exhaust gases leaving the unit.
Problem Statement. The processes in metallurgical units are accompanied by significant smoke and dust, which affect the efficiency of heat transfer from the torch of exhaust gases post-combustion to the metal bath that is an additional source of heat in the converter process.
Purpose. The purpose of this research is to study the influence of the introduction of solid powder components into the environment around the torch on its heat transfer.
Materials and Methods. The research has been carried out on the physical model of a burning torch when CaO-FeO-SiO₂ system powders are fed into the torch in air flow. The magnitude of the heat flow density has been estimated on the basis of the registered temperature difference in different parts of the model.
Results. It has been established that the feed of air or any solid material at a temperature much lower than the torch temperature has a negative effect on heat transfer from the torch by radiation. However, the total heat flow density is not significantly reduced due to the possible involvement of heated solids in other heat transfer methods. For the CaO-FeO-SiO₂ system, the share of silicon dioxide powder as a component with the highest heat capacity has the greatest negative effect on the heat transfer from the torch.
Conclusions. The studies based on the physical model have allowed us to qualitatively assess the effect of dustiness of the components of CaO-FeO-SiO₂ system of the burning torch environment on its heat transfer and on the contribution of different heat transfer methods from the torch to the total heat flow density in given conditions.