Electrolytic cell gas cooling upstream of treatment center

Abstract

The general use of high amperage cells in the last decade has created new challenges for Gas Treatment Centers (GTCs). Aluminum production capacity increases proportionally with the applied electric intensity. This leads to more waste heat by joule’s effect which increases the cell outlet gas temperature. The cell gas temperature also depends on the ambient temperature. In hot climates, gas temperature at the cell outlet could reach 190°C. In such situations, it has become necessary to cool the gases before treatment by HF adsorption on alumina in order to protect the filtration media and to improve the overall scrubbing performance of fluorides. Several technologies have been developed and applied in recent years: dilution air cooling, water atomization in the upstream ducts and heat exchangers. The paper will present a technical and economical comparison of the various gas cooling technologies.