PREVENTING METHOD FOR SCALE DEPOSITION OF EVAPORATION TYPE SEA WATER DESALTING DEVICE

摘要

PURPOSE:To prevent the deposition of scale in an evaporation chamber by heating the sea water injected forcibly with gaseous CO2 in a brine heater and adding a CaCO3 flocculating agent thereto, then introducing the same into an evacuated scale separating chamber thereby depositing and flocculating the scale. CONSTITUTION:After sea water is forcibly injected with the pressurized gaseous CO2 through a line 9 in the process of flowing a condenser K in the upper step, it flows into the heat transmitting tubes of a brine heater 3 and in these pipes, it is heated to around 140 deg.C. A flocculating agent Al2(SO4)3 is added at about 3ppm through a line 11 to the heated sea water, after which it is introduced into an evacuated scale separating chamber 4. In the chamber 4, it flushes and evaporates and CaCO3 scale deposits on account of the sharp drop in the partial pressure of the CO2. The deposited CaCO3 flocculates and settles and the flocs are discharged through a scale discharge line 12 to the outside of the system.