Research on atomization evaporation characteristics and parameter optimization of a novel spray evaporation desalting system

Abstract

Rotary spray evaporation technology has received particular attention due to its superiority in high-salinity wastewater's zero liquid discharge (ZLD). This research develops a new type of high-efficiency and low-energy-consumption rotary spray evaporation tower. The effects of atomization speed, feed flow, feed liquid concentration, hot air temperature, and hot air velocity on high-salinity wastewater's atomization and evaporation characteristics were studied. The numerical results show that the atomization speed can reduce the droplet spraying to the tower wall to reduce the sticky wall phenomenon and prolong the droplet residence time to increase the evaporation rate. By controlling the atomization speed, feed flow, and feed concentration, the droplet SMD can be reduced by 6.0 % to 37.3 % so that the droplets are evenly dispersed. With reasonable hot air temperature and speed, the outlet temperature drops by 19.1 % to 29.0 %, and the evaporation rate increases by 8.7 % to 11.8 %. The optimal working conditions are 16,000 r/min atomization disk speed, 10 kg/h feed flow, 433 K hot air temperature, 10 m/s hot air flow rate, and 93.2 % evaporation rate at this time. The results show that the rotary spray evaporation technology can be a powerful means of ZLD of high-salinity wastewater.