Flashing Feed and Mist Eliminator Performance at Critical Fluid Properties

The design and construction of thermal separation equipment for processing mixtures with critical fluid properties, i.e. low surface tensions and viscosities, is challenging. Conventional design rules are hardly applicable and experimental data are limited. The corresponding design uncertainties lead to costly safety margins and oversized equipment. A separation column mockup with refrigerant cycle setup at our TOPFLOW laboratory allows studying isenthalpic feed flashing and knitted mesh separation capacities at such critical conditions. Liquid surface tension and viscosities can reach below 10 mN/m and 0.5 mPas, respectively, at vapor-liquid density differences between 1400 and 937 kg/m³. This study provides a comprehensive analysis of morphologies in the feed pipe evolving downstream a flash valve. Additionally, knitted mesh flooding points were determined and utilized for a modified design approach for mist eliminators.