SEAWATER DESALINATION DEVICE BY MULTISTAGE FLASH EVAPORATION AND ITS OPERATION

摘要

PROBLEM TO BE SOLVED: To increase the washing effect and to restrain the occurrence of corrosion when stopping the operation of a desalination device by circulating the generated fresh water in a brine circulation system to replace brine with fresh water and subjecting it to flash evaporation again to automatically wash the inside of the device. SOLUTION: In this seawater desalination device by multistage flash evaporation. A fresh water circulating piping 18 provided with a fresh water circulating pump 8 for circulating or taking out formed fresh water and a fresh water circulating switch valve 19 is connected to the inlet part of a brine circulating pump 7 installed in piping of a brine circulating system of the desalination device. When stopping the operation of the desalination device, the generated fresh water is circulated in the brine circulating system to replace brine with fresh water, and is subjected to flash evaporation, thus automatically washing the inside of the device. In this way, the washing and custody operation of the device is automated to unnecessitate the conventional custody operation by human power requiring a lot of labor and cost.