Patent ID: 6150498
Filing Date: 2000-11-21
Classification: B01D,C08F

Abstract:
A method for devolatilizing a polymer-solvent solution, characterized by a single iteration of the following sequential steps:(A) introducing a polymer-solvent solution having a solvent plus residuals content of less than 80 weight percent into a thermal dryer which has a horizontal shell and a rotating shaft inside the shell, disc elements placed in the shaft at an angle, and stationary counter hooks secured to the shell's interior,(B) treating the polymer-solvent solution in the thermal dryer to form product polymer and separated solvent, the separated solvent with residuals therein vaporizing in the thermal dryer to form a vapor containing solvent and residuals,(C) removing the vapor containing solvent and residuals from the thermal dryer, and(D) discharging from the thermal dryer polymer product having not more than 0.5 percent by weight solvent and residuals.