Compatibility of Aluminium Packings with Oxygen — Test Results under Simulated Operating Conditions

Metallic structured packings are used more and more in the cryogenic distillation of air because it results in systems that consume less energy than the conventional distillation tray technology employed before. These packings are normally manufactured from corrugated sheets of thin metal. Aluminium alloys are known to be the best candidate metal for these corrugated sheets because of their good properties at cryogenic temperatures excellent formability, light weight and low cost. The purpose of this investigation was to recheck the oxygen compatibility of aluminium structured packing under simulated operating conditions. First, a series of tests were performed using simplified testing conditions to identify the important parameters, such as oxygen purity, energy supplied (type and level), and oil contamination. These tests were carried out in gaseous, liquid and gaseous/liquid oxygen environments. A second series of tests was performed under simulated operating conditions, reproducing, in particular, the irrigation conditions found in normal service. These tests have confirmed the compatibility of aluminium packings with oxygen under actual operating conditions and confirmed the choice of this material for structured packing.