Devolatilization apparatus and process

摘要

Embodiments of the invention provide an apparatus or process for devolatilization of flowable materials (such as molten polymers with entrained or dissolved solvent or unreacted monomers or comonomers) using a plate heater having heating channels, the design or operation of which heating channels maintains the flowable material above its bubble point pressure during passage through a larger first zone and then induces flashing in, or downstream of, a smaller second zone of the heating channel. The apparatus enables a higher throughput per heating channel while achieving equivalent or better devolatilization, as compared to current devolatilization apparatus.

主权项

1. A process for the devolatilization of a flowable material comprising a liquid or flowable solid, and at least one entrained or dissolved volatile component, which process comprises passing that flowable material through a devolatilization apparatus while operating under devolatilization conditions, wherein said devolatilization apparatus comprises:
(a) a pump for supplying a pressurized flowable material comprising at least one molten polymer and at least one dissolved or entrained volatile component, which flowable material is characterized by a bubble point pressure which varies with the temperature of the flowable material, (b) a collection-and-volatile-separation vessel, and (c) a multiplicity of plates defining a plurality of heating channels, each heating channel having a substantially uniform height and having two zones consisting essentially of:
a first zone having (1) an average hydraulic radius, and (2) an inlet adapted to receive the flowable material from the pump, anda second zone constituting the remainder of each said heating channel, which said second zone is adapted to receive the flowable material from the first zone and has at least one outlet adapted to discharge the flowable material into the collection-and-volatile-separation vessel, wherein the outlet of the second zone consists essentially of a smaller hydraulic radius than the average hydraulic radius of the first zone thereby resulting in a substantially complete flashing of the volatile components from the flowable material within the second zone, and wherein the ratio of the average hydraulic radius of the first zone to the hydraulic radius of the second zone having the smallest cross-sectional area is from 1.05:1 to 10:1; andwherein the design or operation of at least some of the heating channels is such that the pressure of the flowable material at essentially all positions within the first zone of those heating channels exceeds the bubble point pressure of the flowable material, and (d) a plurality of heating elements adapted to heat at least some of the plates so as to increase the temperature of the flowable material as it flows through the heating channels.