Minimizing Entrainment From Flashing Feeds: Analysis of Process Parameters and Orifice Design

This study investigates droplet entrainment from flashing feeds in a forced circulation flash evaporator, focusing on how liquid breakup governs droplet carryover into the vapor phase. Experiments with water and three orifices of different aspect ratios were performed. The effects of liquid velocity, superheat, and orifice geometry were evaluated. For water, a superheat degree of about 20 K marks the transition from mechanically to flashing dominated breakup, accompanied by a change from linear to exponential increase of entrainment with a gas load factor of about 2 Pa 0.5 . Longer orifices promote internal flashing and finer atomization, whereas shorter orifices favor external flashing and coarser sprays, but may form wall impinging jets with locally very high entrainment.