Method and apparatus for feeding chopped polyester scrap
US5765728A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 10, 1996 |
| Grant date | Jun 16, 1998 |
| Priority date | — |
| Expiry date | Jul 10, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65G69/20
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved system (10) conveys comminuted material from a source (12) to a vessel (14), especially for continuously conveying chopped poly(ethyleneterephthalate), or PET, into a methanolysis recovery reactor without entrainment of air into the reactor and without frequent jamming of the apparatus. A single rotary vane valve (36) is provided in the conveyance path at an inlet (38) to the vessel. The valve has clearances between the vanes (44) and the housing (48) larger than the smallest dimension of the comminuted material to prevent jamming of the rotor by PET flakes. The internal spaces (52, 47) in the valve are continuously purged with nitrogen at sufficient volume and pressure such that gases and fumes in the vessel are substantially prevented from passing upward through the valve. Nitrogen also flows from the valve countercurrently through the supply ducts (26, 30) to strip entrained air from the incoming material. Preferably, additional nitrogen is introduced into the supply duct (30) ahead of the valve to assist in air removal from the material. Internal valve surfaces (64) are heated to prevent condensation of gases and fumes from the vessel, thereby preventing sticking an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.