Multi-shaft screw extruder
US4162854A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 1977 |
| Grant date | Jul 31, 1979 |
| Priority date | — |
| Expiry date | Mar 2, 1997 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C48/03
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The screw extruder is provided with screw shafts arranged so as to intermesh in pairs and rotate in pairs in the same sense, each screw shaft of a pair containing at least one double or triple threaded pressure build-up section corresponding to that of the other screw shaft. At least part of the pressure build-up sections have at least a ratio of screw pitch t to housing inner diameter d within the range: PA1 0.7.multidot.f(h/d, .delta./d, q/nd.sup.3)<t/d<1.8.multidot.f(h/d, .delta./d, q/nd.sup. In which q is the volume throughput of one screw pair, n is the screw shaft rotational speed, h is the thread depth, measured from the screw thread base to the housing inner wall, .delta. is the radial screw clearance between the screw crest and the housing inner wall and f is a function between the above values which is specified in the description.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.