Impact of Specific Number of Air to Clinker on Clinker Cooling Process in Grate Coolers in a Cement Plant

The impact of specific number of airs to clinker on a clinker cooling process in grate coolers in a cement plant was investigated. Clinker cooling process is a complex process due to the vast number of interacting operating parameters such as: clinker cooler length, ambient temperature, clinker cooler width, clinker cooler drives speed, clinker cooler fan speed, clinker and air mass flow rates, and clinker density and air densities. This research examines heat transfer and multiphase fluid flow analysis as relating to specific number of air to clinker in a clinker cooling system. It employs a physical "dimensionally scaled-down" model. A 3D model of the clinker bed was developed using SolidWorks 2014 based on geometric parameters adopted in the scaled conceptual design after an existing running clinker cooler. The designed model was scaled down by ratio 25:1, that is, existing cooler being twenty-five times higher than the modelled with length 1.3 m, width 0.3 m and variable clinker bed height of 0.3 m, 0.4m and 0.6m as geometric dimensions. Numerical experimentation done involved high temperature clinker entering the clinker cooler from the heating-up furnace (HUF) at 1350 °C, specific numbers of 2.2041 and 1.7959 Nm3/kg clk, air inlet temperature of 32 °C, inlet mass flow rate of air at 0.45 kg/s at clinker 0.15 kg/s. It was observed that at a specific number of 2.2041 Nm3/kg clk at a bed height 0.6 m an optimal energy recoverable efficiency of 70% was recovered into the system and with an improved lower outlet clinker temperature of 68 °C. While, at a specific number of 1.7959 Nm3/kg clk and at a clinker bed height of 0.3 m, the lowest recoverable efficiency of 57.52% was recovered into the modelled clinker cooler and with highest outlet clinker temperature of 168.7 °C. Hence, specific number of airs to clinker also plays a significant role in clinker cooler performance.