Experimental and numerical investigation on evaporation characteristics of high salinity wastewater by rotary spray

Zero Liquid Discharge (ZLD) of high salinity wastewater is always an important subject in the field of energy and environment. In order to improve the evaporation rate, the mass and heat transfer characteristics of the rotary spray evaporation technology in the treatment of high salinity wastewater are explored. The relationship between the evaporation characteristics of wastewater and various parameters such as hot air flow rate, hot air temperature, feed flow rate, atomizing disk rotating speed and feed liquid concentration change is studied by experiment and simulation. It is concluded that the hot air temperature and hot air flow rate are important factors affecting the evaporation effect of the system. The atomizing disk rotating speed and the feed flow rate have a great influence on the atomization effect of the atomizer. A fluid recirculation area is generated around the atomizing disk, which allows droplets to reside longer in the evaporation chamber, thus improving the evaporation efficiency. Compared with other factors, the effect of feed liquid concentration on atomization and evaporation is relatively small. Finally, a better process operation condition is obtained through research: the atomizing disk rotating speed is 24,000 r/min, the feed flow rate is 4.5 kg/h, the hot air temperature is 498 K, and the hot air flow rate is 80 m(3)/h.