Method for concentration of foaming liquids

Claim 1

An improved process for concentrating a heat-sensitive, liquid, foamable, aqueous dispersion of a non-volatile organic material which comprises A. adiabatically vaporizing a heated stream of latex at a reduced pressure to form a two-phase stream consisting of a liquid phase and a vapor phase, causing said heated stream to pass through an elongated cylindrical evaporation zone under conditions designed to provide annular flow and equilibrium between the vapor and the liquid phase and suppress foaming and spray flow, B. subjecting the equilibrated stream of step (A) to centrifugal forces in the outlet end of said evaporation zone, and C. adiabatically separating said liquid phase from said vapor phase by further centrifugal and gravitational forces in a separation zone, said liquid phase being the concentrated latex and said vapor phase being substantially all evaporated water; wherein the latex is a latex of a rubbery polymer and it is heated to 130°-155°F and is fed to the vaporization zone at 30-45 U.S. gallons per minute and a vacuum of about 0.6 psia is maintained in the vaporization zone of which the diameter and length are 1.5 and 10 feet respectively.