Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Mechanical defibration in the presence of heated gas or gas...
Patent
1980-06-17
1981-08-11
Chin, Peter
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Mechanical defibration in the presence of heated gas or gas...
162 68, 241 18, 241 23, 241 28, D21B 114, B02C 2324
Patent
active
042832527
ABSTRACT:
Method and apparatus for producing thermo-mechanical pulp from wood chips and the like in which the chips are first heated in a steaming chamber or preheater to a fiber temperature below the softening point of the lignin of middle lamella section of the wood fibers. The thus heated chips are conveyed in a sealed system to the inlet of a difibrating zone enclosed within a housing in a gaseous atmosphere of superatmospheric pressure, where it is compressed by a screw conveyor into a plug which seals the defibrator housing against blow-back of the pressurized gaseous medium. The defibrating space is defined between a pair of grinding discs which rotate relatively to one another in the housing and comprises a first substantially central zone into which the compressed plug is advanced by the compressor screw and broken up and the fibers subjected to an initial defibration step at a fiber temperature below the softening point of the lignin, to cause the fibers to unravel and to expose the different fiber layers without any substantial separation thereof. As the fiber bundles progress radially outwards under the centrifugal force of the rotating discs into a second zone radially surrounding the first zone, the temperature increases by the heat of the grinding friction which converts water accompanying the chips into high temperature, high pressure steam, in which environment the lignin is softened so that the wood structure is broken in the lignin-rich middle lamella section of the fibers to permit the fibers to become completely separated and fibrillated in undamaged condition. The resultant pulp is discharged from the pressurized housing through a blow valve which is adjustable to control the pressure and temperature within the defibrator housing.
REFERENCES:
patent: 2396587 (1946-03-01), Lowgren et al.
patent: 3215355 (1965-11-01), Shouvin et al.
patent: 3910505 (1975-10-01), Reinhall
Defibrator News, 1:1974, pp. 1-12.
Chin Peter
Munson Eric Y.
LandOfFree
Method and apparatus for producing fiber pulp from fibrous ligno does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for producing fiber pulp from fibrous ligno, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for producing fiber pulp from fibrous ligno will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1024673