Energy-Efficient Cooling and Hydraulic Descaling Systems

Abstract

Determination of real boundary cooling conditions is a fundamental requirement for numerical models and simulations to optimize and control selected processes in metallurgy. To obtain these boundary conditions, a special method has been developed. The input temperature history of cooling is obtained from experiments. The measured data are then mathematically evaluated. Realistic boundary conditions, as the heat transfer coefficient between hot surface and the coolant, allow optimization of the cooling sections and the design of their configurations. To realize the cooling test, unique laboratory equipment was developed. It allows setting of cooling conditions close to the plant conditions. The paper presents examples of optimization of work roll cooling, examples of design of sections for in-line heat treatment of metals and procedure for designing new high-pressure descaling sections. The methodology proposed by the Heat Transfer and Fluid Flow Laboratory of the Brno University of Technology is typically used to determine the heat-transfer coefficient on the surface of high-temperature material in the applications of heat treatment, cooling of rolls of hot rolling mills, and high- pressure descaling. The methodology enables identifying the effect of nozzle water jets on the heat-transfer coefficient or on removal of high-temperature scale and leads to cooling and descaling optimization for industrial partners.