Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Continuous chemical treatment or continuous charging or...
Patent
1979-12-03
1982-12-14
Alvo, Steve
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Continuous chemical treatment or continuous charging or...
162 57, 162 65, 162241, 162243, D21C 910
Patent
active
043636977
ABSTRACT:
Medium consistency oxygen delignification of pulp is carried out in a series of tubular reaction zones. Rapid delignification is achieved by agitating the pulp by rotating a timing screw in the first reaction zone at a speed in excess of 10 rpm, modifying the flights on the timing screw to increase the amount of agitation, or a combination of the two. Primary oxygenation is carried out in the first reaction zone while subsequent zones provide the retention time needed for the delignification reaction to go to completion. A thick stock pump is used to introduce the pulp into the first reaction zone.
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Hasvold; "Waste Utilization-Oxygen Delignification of Sulfite knots", 1978, International Sulfite Conf., Montreal, Canada, Sep. 13, 1978.
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Eklund Henrik J.
Markham Larry D.
Air Products and Chemicals Inc.
Alvo Steve
The Black Clawson Company
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