Details

Grate coolers which represent one of the pyro-processing units are extensively used in cement industries. The essential function of grate coolers is a waste heat recovery from hot clinker which leaves the rotary kiln. This work subdivides in two parts; in first part, it presents a new analysis of energy and exergy based on the clinker temperature profile. It focuses on the distributions of temperature, energy and exergy for cooling air and hot clinker along the grate cooler in cement industries. It was found that the heat exchange, clinker exergy and cooling air exergy, could be increased by 8.26%, 8.22% and 8.04 % respectively with every 5% increment in clinker mass flow rate. In second part, it emphasizes the ability to recover the heat losses via heat the working fluid of a cogeneration cycle directly and indirectly. On the other hand, the recovery cycle was added with different working fluids (water, oil and air) to recover the waste heat and to heat the working fluid of cogeneration cycle. The energy efficiency of the first method was approximately 26% and it represented better than the second method. The first method gave the best results in terms of energy and cost savings.