Patent ID: 7288620

Claim:
In a device for the continuous manufacture of an aromatic alkylene polymer, having a zone for the bulk polymerization of an aromatic alkylene monomer that is linked to a polymer devolatilization zone successively including at least one first devolatilizer DV 1 and one second devolatilizer DV 2 so as to separate polymer from unreacted monomer and oligomers formed at least partly during the polymerization, the improvement comprising: a first line for removing a first gas stream from DV 1 that links DV 1 to a first zone Z 1 for direct condensation and fractionation, a first top withdrawal line for removing from a top of zone Z 1 a gas stream G 1 essentially comprising monomer, a first bottom withdrawal line for removing from a bottom of zone Z 1 a liquid stream L 1 rich in oligomers, and a recycling line for returning a portion of the liquid stream L 1 in the first bottom withdrawal line to a cooling unit and then to the first zone Z 1 , and a second line for removing a second gas stream from DV 2 that links DV 2 to a second zone Z 2 for direct condensation and fractionation, said first bottom withdrawal line also being linked to the second zone Z 2 so as to feed zone Z 2 with another portion of the liquid stream L 1 , a second top withdrawal line for removing from a top of zone Z 2 a gas stream G 2 comprising monomer, and a second bottom withdrawal line for removing from a bottom of zone Z 2 a liquid stream L 3 essentially comprising oligomers.