SPRAY EVAPORATION OF BRINE SOLUTIONS

The spray evaporation of brine solutions, for the purpose of salt production, was studied. The water evaporation rate was studied for different climatic conditions, namely relative humidity, air temperature and wind speed, and brine properties like temperature and salt concentration. Two different situations were highlighted: warm brines at about 70oC, and brines at temperatures near ambient temperature where heat transfer from the air occurs. Full scale data obtained in a solar-spray pond of a salt production plant are presented. Theoretical approaches to modeling the two different situations above mentioned are formulated and the corresponding evaporation rates estimates are compared with the experimental data. The energy losses (by radiation and convection) in the case of warm brines are relatively small (about 20 %). For brines at temperatures around ambient temperature, the energy transfer from the air, and hence the increase in salt production, can be a significant contribution to the total energy involved in the brine evaporation process.