Abstract

It is well known that cement production is one of the most energy consuming industries in the world and comes after steel industry (19.7%). For this reason, energy saving and efficiency efforts target these industries in the first place. The method developed for cement industry, in which the ratio of energy costs with respect to total costs is very high (55%) that provides the optimum working ranges according to energy costs and efficiency for the units.  Additionally, in the case of a problem occurring in the system, whether the source is a parameter or not on a unit is detected easily. In this paper, a mathematical model related to energy and exergy balance for four-stage cyclone precalciner type cement plant is developed. The energy and exergy balances for the whole system and each unit are calculated and presented. The results showed that the first and second law efficiencies were 51 and 28%, respectively. Total exergy loss of the system was found to be about 72%.

Key words: Parallel flow, precalciner, cement, energy and exergy analysis, mathematical model.