Modeling of rotary kiln for sponge iron processing using cfd package (ANSYS 13.0)

Abstract

CFD analysis of heat transfer in freeboard of rotary kiln was done with licence version of ANSYS 13.0, authorized by NIT Rourkela. ANSYS 13.0 is an engineering simulation software (Computer-Aided Engineering. Kiln of a typical Sponge Iron producing plant having capacity 500 Tons Per Day was modelled and simulated with CFD package (ANSYS 13.0). This kiln is of length 80m. and inner diameter 4.34m. Kiln was assigned with 9 air tubes to get a maximum turbulence for better temperature profile.A horizontal cross-section of kiln was modelled in a 2D geometry.These air tubes are separated from Inlet end to outlet end at distances of 8.1, 8.1,5.7, 6.7, 6.7, 6.7, 6.7 & 4.6 respectively. Air flow rate in these tubes 10000 cubic meter/hour. Air flow of 15000 cubic meter/hour mint for central blower spliced into two streams. A larger stream for Axial flow and smaller for radial flow. Axial flow is responsible pushing flame in forward direction. Radial flow pushes the flame in along Y-axis to rise the flame coverage diameter.Flame profile of kiln was modeled two values of with Axial to Radial volume ratios. Simulated proportions were 9:1 and 8:2.The simulated result of two proportions were compared at various time.