Method for cleaning water by freeze crystallisation

摘要

Method for continuously cleaning lightly polluted water where the water from a storage tank (1) is cooled in a heat exchanger (4) and enters a recirculation loop (5, 6, 8) with a cooler (5) where it is seeded with small ice crystals, and an insulated tank (6) where the ice crystals grow. At the tank (6), ice crystals are filtered out (62), washed and filtered (10), thawed (4) and discharged (15) as cleaned water. The liquid from the wash column (10) returns (20) to the loop (5, 6, 8), and a proportion of the conc. liquor is drawn off (21) for disposal. Novelty is that the drawn-off concentrate (21) is dosed with a coagulant (24) and enriched with solids (25) before being collected for disposal (27).