Patent ID: 6174411
Filing Date: 2001-01-16
Classification: D21C

Abstract:
A method of operating a continuous cellulose pulp digester having a top and a bottom, an inverted top separator at the top, the inverted top separator having a top and a bottom, and a discharge at the vessel bottom, comprising the steps of:(a) introducing a slurry of comminuted cellulosic fibrous material and liquid including free liquor, into the continuous digester through the inverted top separator;(b) establishing a liquid level in the digester above the bottom of the inverted top separator;(c) establishing a level of cellulosic fibrous material in the digester below the bottom of the top separator;(d) withdrawing liquor from the inverted top separator at at least one location so as to remove at least some of the free liquor from the introduced comminuted cellulosic fibrous material slurry; and(e) withdrawing kraft pulp from adjacent the bottom of the continuous digester, at a rate of more than about 1000 metric tons per day.