Aluminium recycling with fuzzy logic

Typically, recycling scrap aluminium requires only 5% of the energy needed to produce the same amount of metal from bauxite ore. Clearly, this makes the process very attractive, both in financial and environmental terms. If, however, high levels of throughput, combined with efficient recovery, are to be achieved, sophisticated recycling furnaces are needed.



e4engineering.com reports that to this end, recycling expert Platinum Controls has developed a new range of ultra-efficient recycling furnaces that feature innovative control systems. Platinum specialises in the development of these furnaces, and the results achieved by its latest models are such that, in many applications, they have a payback period of just six months.



These furnaces comprise a refractory-lined cylindrical drum, which rotates and tilts while applying heat from gas/air burners to the scrap material. At the end of the melting period, the rotation ceases, and the drum is tilted to allow the molten aluminium to be poured off.



The process sounds simple, but achieving consistently good performance depends on precise control over variables such as temperature, rotational speed, tilt angle and melt time. Platinum has used equipment and technology from Omron Electronics to implement this precise control for the new furnace.



Omron’s fuzzy logic system allows the process to be optimised on the basis of simple rules that can be refined over time. This approach, which does not depend upon the development of accurate mathematical models, is proving very successful in making the recovery rate less dependent upon the skill of the furnace operator. Efficiency gains of around ten per cent are already being achieved, and even higher gains are expected as the fuzzy logic is fine-tuned.