Patent ID: 6030492
Filing Date: 2000-02-29
Classification: D21C

Abstract:
A method of continuous cooking of kraft pulp, the method comprising the steps of:providing a single vessel system having a concurrent impregnation zone, a cooking zone and at least one extraction screen section, the single vessel system having a first end and an other opposite end;providing a high pressure feeder in communication with the first end of the single vessel system via a transfer line;providing chips;providing a first liquid;providing an amount of a second liquid containing an amount of black liquor that is at least 40% of the amount of the second liquid;providing a liquid exchanger in operative engagement with the transfer line;conveying the chips and the first liquid from the high pressure feeder via the transfer line to the liquid exchanger;separating the first liquid from the chips in the liquid exchanger;replacing the first liquid with the second liquid;conveying the second liquid and the chips to the first end of the single vessel system;impregnating the chips in the concurrent impregnation zone with the second liquid;cooking the chips in the cooking zone;extracting hot black liquor from at least one extraction screen section; anddischarging a cooked pulp at the other opposite end of the single vessel system.