Measurement of Temperature Dependent Dielectric Constant of Coal Samples for Burden Surface Profiling at Blast Furnace

Abstract

Blast furnaces (BFs) are the key receptacles of iron and steel smelting. Iron ore, coke and limestone are some of the raw materials that are used in the process of iron making and the charging operation needs to be accomplished by accurately estimating the current depth of the burden surface. To accomplish the goal of global class steel production, burden profile measurement and monitoring is vital. This measuring and monitoring help in augmenting the best usage of charge materials and energy consumptions.
 Radar based measurement is best for determine the level and profile of the burden inside the furnace. However, for the optimal operation of the radar, it is important know the dielectric constant of the material. There are many approaches to determine the dielectric constant like capacitive methods, transmission line methods, cavity resonator methods, open cavity methods and so on. For this study the cavity resonator method is has been used for measuring the permittivity of coal samples. The reflection capability of electromagnetic waves by coal is a function of its dielectric properties which is also has a dependency on temperature. The results presented in this paper will provide essential design input for radar-based measurements at blast furnace, especially for burden profiling at blast furnaces.