PROCESS AND APPARATUS FOR THE OXYGEN DELIGNIFICATION OF PULP

摘要

PROCESS AND APPARATUS FOR THE OXYGEN DELIGNIFICATION OF PULP A medium consistency oxygen delignification process and apparatus are provided utilizing one or more substantially horizontal agitated tubular reaction zones. The process produces rapid delignification rates at low alkali charges, minimizes oxygen requirements, and yields pulps having high viscosities. The use of rotary screws or paddles in the reaction zone or zones provides the agitation required to enable good mixing of oxygen with the medium consistency pulp and alkaline chemicals as well as controlling the pulp retention time in each reaction zone. The process tolerates the presence of up to 20% entrained black liquor solids without significant adverse effects on the pulp.