Abstract: Disclosed is a multiple-stage flash devolatilization process, and apparatus for use therein, for recovering volatiles from mass processable polymers, which enables optimally low pressures to be employed without the necessity for refrigeration to condense the volatiles recovered thereby, comprising separating the volatiles from the polymeric material by flashing in a first flash devolatilization zone to remove the majority of the volatiles and then flashing in at least one additional flash devolatilization zone maintained at a lower pressure, preferably as low as practically possible, to remove residual volatiles, and then recovering the volatiles for further use by feeding the volatiles recovered from the additional flash zones back into the first flash zone, the higher pressure of which allows the combined free volatiles present therein to then be condensed in a conventional non-refrigeration cooling process.

Abstract: A mixer and/or heat exchanger for flowable compositions includes dual, parallel, interconnected cylindrical mixing chambers through which intermeshing, counterrotating bladed mixer elements extend. The mixer blades sweep virtually the entire inner surface area of the chambers and the entire volume within the chambers. The interconnection between the chambers is designed to minimize unswept space within the chambers, and heat exchange medium is circulated around the chambers so the system can be used to heat or cool the composition moving through the mixer.