Patent ID: 8245521

Claim:
A process for concentrating dilute solution, said process comprising: (a) supplying dilute solution to be concentrated in a vertical freeze concentration column so that dilute solution travels in the downward direction toward a lower end of the freeze concentration column; (b) producing localized freezing and micro-size ice particles near the lower end of the freeze concentration column so that the ice particles travel towards an upper end of the freeze concentration column; (c) collecting ice particles near the upper end of the freeze concentration column; (d) melting ice particles collected in step (c) and subsequently re-circulating part of the liquid to the freeze concentration column so that said liquid travels towards the lower end of the freeze concentration column; (e) repeating the steps (a) to (d) for fractionating dissolved solid concentrate and aqueous solution near the upper and lower end of the freeze concentration column respectively till the desired concentration of the dissolved solid is achieved; and (f) obtaining the concentrate from the lower end of the freeze concentration column.