Solar tower based aluminum heat treatment system: Part I. Design and evaluation of an open volumetric air receiver

Electrical energy is employed for processing operations of material, such as, smelting, soaking and heat treatment. During this process, fossil, coal, and nuclear as a fuel is employed. Extraction and use of these fuel sources have serious environmental implications. Moreover, the employed process involves conversion of fuel to heat and then to electricity. Double conversion process can be avoided by directly introducing hot air provided by a solar tower equipped with a volumetric air receiver into a retrofitted furnace. This is a clean, green alternative for generating high temperatures required for metals processing operations. Initially a system would be developed for the heat treatment of aluminum, which requires temperature between 290 and 400 °C. A survey of the literature shows that quantitative design basis of individual volumetric air receiver components is conspicuous by its absence. Hence the objective of this investigation has been to use principles of fluid flow and heat transfer to design individual components of an Open Volumetric Air Receiver (OVAR) system. Experiments on a 2 kWth Solar Air Tower Simulator system (SATS) validate the process used in designing individual components of the OVAR. The ultimate aim of this research is to develop a system that can be used for heat treatment of steels and other possible extractive metallurgy operations such as the smelting of metals from its ores.