Raising of energy efficiency of thermal performance of layered metallurgical units using layered type of natural gas combustion

Abstract

Abstract While heating lump materials there are some difficulties such as poorly organized process of grate firing, conditions deterioration of gas-air mixture creation, limited discharge of combustion products out of a layer due to additional aerodynamic drag occurrence when gases flow. Grate firing of gaseous fuel can be completed in a dense layer of lump materials which have different chemical composition and particle-size distribution. To do this, it is necessary to provide formation of high-temperature area and complete thermal generation process directly between separate elements of treated materials. It allows providing specified temperature-time conditions of heat treatment of the different layer sections. Also, it is required to limit the direct contact of the high temperature zones with external boundaries of the unit smelting chamber and environment for increasing reliability and effectiveness. In this paper, we present existent heat-exchange schemes in grate process units during the heat treatment of lump materials. An ability of grate firing of gaseous fuel while organizing a delivery of prepared gas-air mixture into a dense layer or separate tuyer gas and air supply with separate flows is shown. Usage of indicated ways of feeding allows decreasing energy demands and improving quality of products delivered.