Such phenomena as serious scaling

low performance ratio and gradually decreased water yield occurred during initial operation of the first domestic low temperature multi-effect seawater desalination(LTMED)equipment.By recalculating the operation parameters

it found that the too large designed injection coefficient of steam compressor caused the small amount of desuperheating water

and over high temperature of steam entered the first effect

so the scaling occurred.Too large amount of steam extraction led to larger performance ratio.Besides

blocking in sea water nozzle and uneven water distribution were also important reasons for the system scaling.After several measurements were taken

like pickling and descaling

cleaning the nozzle

adjusting the desuperheating water and so on

the water yield and performance ratio were recovered.Furthermore

after six months’running

no scaling occurred again.