Analysis of the parameters affecting energy consumption of a rotary kiln in cement industry

• We analyzed a rotary kiln and investigated the first law and second law efficiency values.
• Performance assessment of a kiln indicates that the burning process involves energy and exergy losses.
• The anzast layer affect the efficiency and production capacity of the kiln.
• The specific energy consumption for clinker production is determined.

In this study, the effects of refractory bricks and formation of anzast layer on the specific energy consumption of a rotary kiln are investigated. Thermodynamic analysis of the kiln is performed to achieve effective and efficient energy management scheme. Actual data, which are taken from a cement plant located in Gaziantep, Turkey, are used in numerical calculations to obtain energy balance for the system. It is calculated that 12.5 MW of energy is lost from the surface of the kiln which accounts for the 11.3% of the total energy input to the unit. The specific energy consumption for clinker production is determined to be 3735.45 kJ/kg clinker. The formation of anzast layer and the use of high quality magnesia spinel and high alumina refractory bricks provide 7.27% reduction in energy consumption corresponding to a saving of 271.78 MJ per ton of clinker production. It is recognized that the anzast layer has an important role for durability of the refractory bricks and heat transfer out of the kiln. The applications prevent the emission of 1614.48 tons of CO2 per year to the atmosphere.