PURPOSE: To prevent a soln. contg. salts from being mixed in cooling water and to keep the purity of the recovered water high by keeping the deaerated cooling water to be introduced into the cooling chamber of a membrane evaporative concentrator at a pressure higher than that of the soln. contg. salts to be introduced into an evaporation chamber opposed to the cooling chamber with a hydrophobic porous membrane in between.
CONSTITUTION: A soln. contg. salts in a storage tank 4 is heated to a specified temp., supplied to the evaporation chamber 13 of a membrane evaporative concentrator 1 through a circulating line 2 and circulated through a circulating line 2A. Meanwhile, the pure water in a storage tank 7 is cooled to a specified temp., supplied to the cooling chamber 14 of the concentrator 1 through a circulating line 3 and circulated through a circulating line 3A and a deaerator 10. The high-temp. soln. in the evaporation chamber 13 and the low-temp. cooling water in the cooling chamber 14 are separated by a membrane 12. Since a hydrophobic porous membrane is used as the membrane 12, only the steam generated from the soln. is passed through the pores of the membrane and condensed on the cooling water side. An excess of the condensed water is recovered, for example, from the tank 7 of the lines 3 and 3A.
FUNABASHI KIYOMI
SAWA TOSHIO
KIKUCHI JUN
