Immediate success for rapid development
The EME / SORG batch preheater is the result of a development project carried out over a number of years. Following the concept definition phase the first trial unit was built in 2010 and this provided important insight into the problems involved. At higher temperatures soda ash releases its water of crystallisation and this encourages the tendency for the batch materials to form clumps. The next stage of the development concentrated on the application of a preheater unit to remove the moisture at an early stage.
This culminated in a prototype unit that was able to remove the moisture before it could cause clumping. A full-size version of the important parts of the preheater was built and tested under realistic conditions. This included the use of different batch compositions, cullet contents and moisture levels. The wear level of critical components was measured and the wear resistance optimised.
The batch preheater is modular so that the capacity and throughput can be easily adapted to suit various furnace sizes. Moisture released and the dust produced are removed in a controlled manner. The hot waste gases from the furnace pass through the heat exchanger modules of the preheater and heat is transferred to the batch as it moves toward the batch charger. At the same time the heat exchanger parts are vibrated to destroy any remaining material clumps and ensure the free flow of material through the preheater unit.
The first production system for container glass in which the complete raw material supply to the furnace was passed through the preheater was installed in 2011. A by-pass was provided for use in emergencies and during maintenance. The percentage energy savings attributed to the use of the batch preheater and the other components of the Batch³ concept, determined over a period of several months were found to be in double figures and were actually somewhat higher than had been predicted. The same customer placed an order for a second system in 2012 and this is expected to be in operation at the beginning of 2013.