Process for the multistage generation of vacuum for polyester production
US5466776A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 9, 1995 |
| Grant date | Nov 14, 1995 |
| Priority date | — |
| Expiry date | Feb 9, 2015 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G63/78
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Process for multi-stage generation of a vacuum and condensation and recycling of the vapors of polycondensation in the production of polyester, where the last stage includes a liquid ring pump compressing to atmospheric pressure, a cooler and a degasifier tank. The process also includes at least two preceding stages each using a glycol vapor jet that is operated with superheated glycol vapor at a pressure in the range of 0.8 to 1.0 bar abs. and a downstream glycol spray condenser whose operating conditions are regulated to condense a maximum quantity of glycol and at the same time causing the low-boiling reaction by-products including water to remain in the gas phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.