Patent ID: 7252743

Claim:
A concentrating tank for concentrating a polymer solution in which a solute is dissolved in a solvent, comprising; a tank main body for temporarily containing said polymer solution which is concentrated; means for evaporating a solvent gas from said polymer solution; a roof disposed on said tank main body, an inclined inner surface of said roof forming a condensing surface for condensing the solvent gas evaporated from said polymer solution; at least one flash nozzle inserted into said tank main body, said at least one flash nozzle being disposed under a solution surface of said polymer solution in said tank main body, for discharging a supplied fresh polymer solution into said polymer solution which is concentrated in said tank main body, said nozzle being for performing a flash evaporation of said polymer solution in said tank main body; and a draining pipe connected to a bottom of said tank main body for draining a concentrated polymer solution.