Measuring Entrainment from a Spray for Industrial Applications

Liquid entrainment occurs between distillation trays, from spray nozzles, above mist eliminators, and in kettle reboilers. Information pertaining to the drop size distribution and total volume of entrainment is crucial information for the design and operation of such equipment. While many aspects of spray dynamics have been correlated and quantified, information regarding the entrainment rate is limited. This study of entrainment from a spray nozzle has been conducted in a spray column capable of reliably capturing entrained droplets and measuring the entrained droplet size distribution using Phase Doppler Interferometry (PDI). A method was developed to quantify the total volume of liquid entrained from a full cone Bete^® nozzle using PDI droplet size data for a water/air and a 0.1 N sodium hydroxide (NaOH)/air  system. PDI results showed that increasing the liquid rate results in a decrease in the entrained droplet Sauter mean diameter and an increase in total liquid entrained. Corresponding results showed that increasing the gas rate results in a decrease in entrained droplet Sauter mean diameter and an increase in the total liquid entrained.