Patent ID: 7776998

Claim:
A process for the separation of volatile material from particulate polymer, comprising: (a) feeding the particulate polymer which has been substantially freed from unreacter monomer in an earlier separation step using an inert gas to a purge vessel and causing it to move through the vessel in substantially plug-flow mode, (b) heating the particulate polymer in the purge vessel to a temperature greater than 30° C. but insufficiently high to cause the polymer particles to become agglomerated, and/or maintaining the polymer at a temperature in this range in the purge vessel, (c) feeding gas to the purge vessel to remove volatile material therefrom, removing the particulate polymer from the purge vessel, wherein substantially all of the heating of the polymer particles which occurs in the purge vessel is accomplished by preheating the gas fed into the purge vessel and at least a portion of the gas fed to the purge vessel enters the vessel at one or more points located closer to the top of the vessel than to the bottom.