PURPOSE: To make it possible to operate a polyester polymerization apparatus stably for a long time by preventing a mechanical vacuum pump from being clogged due to deposition of lower polymer, by injecting a glycol onto the surface of the rotor of the mechanical booster.
CONSTITUTION: A mechanical vacuum pump as means for maintaining the reaction system at a predetermined vacuum in the polymerization of a polyester comprises a combination of one or more mechanical boosters 2 with a liquid- sealed pump 3. A provision is made for nozzle 2e for injecting a glycol toward the direction of the surface of the rotor 2b of each mechanical booster 2. From this injection nozzle 2e, a glycol is continuously or intermittently injected toward the surface of rotor 2b. The glycol in this case is desirably the same as a starting material for the polyester. The glycol injected into the mechanical vacuum pump together with lower polymer is discharged from the system through a drain blow 4b and recovered.
| JP6093116 | Vacuum pump |
| WO/2021/079087 | SENSOR ASSEMBLY |
| JPS52101703 | VACUUM PUMPS |
KATOU YOSHIMASA
ONISHI KIYOTAKA
