Cement production line has been one of the most energy intensive industries in the world. In order to produce clinker, rotary kilns are widely used in cement plants.

This paper deals with the energy audit analysis of a dry type rotary kiln system working in a cement plant in Turkey. The kiln has a capacity of 600 ton-clinker per day. It was found that about 40% of the total input energy was being lost through hot flue gas (19.15%), cooler stack (5.61%) and kiln shell (15.11% convection plus radiation). Some possible ways to recover the heat losses are also introduced and discussed. Findings showed that approximately 15.6% of the total input energy (4 MW) could be recovered.

The purpose of tyres (often called riding rings) and rollers is to support the kiln and allow it to rotate with minimal friction. Rotary kilns are among the largest items of permanently moving industrial machinery, the largest examples weighing in their fully-loaded form several thousand tonnes. Despite the challenges of their size and their high temperature, the best examples of rotary kiln rotate on their rollers almost frictionlessly, the power supplied by the drive being almost entirely in order to oppose the eccentric load of the contents of the kiln. On cutting the power to a kiln, the kiln will “roll back” and unless a brake is applied, will continue to swing like a pendulum for ten or fifteen minutes before coming to a standstill. This finely-tuned mechanical condition requires sophisticated design of the kiln’s supports.

 

Both these seals have to deal with high temperatures, and so must be either of a simple heat-proof design, or must be kept cool by means of external fans. Both must also be capable of remaining air-tight as the kiln expands and contracts, and must cope with rotation of a kiln that may be slightly distorted.