Patent ID: 8106150

Claim:
An apparatus for manufacturing polylactide which includes the steps of preparing lactide through oligomerization of lactic acid and depolymerization of the resulting oligomers, effecting ring-opening polymerization of the lactide, and removing unreacted lactide from the resulting polymers, the apparatus comprising an exhausting gas treatment device for reducing pressure in the step of removing unreacted lactide, wherein the exhausting gas treatment device includes: a boiler for generating water vapor; a pressure-reducing section having a stage including an ejector driven with the water vapor, a condenser connected downstream of the ejector, and a hot well tank connected to the condenser; and a main condenser and a main hot well tank connected to the main condenser, the main condenser and the main hot well tank being disposed on a pipe line through which a gas of the unreacted lactide is suctioned into the pressure-reducing section, and wherein the gas of the unreacted lactide is washed away in the main condenser with the use of a liquid collected in the main hot well tank.