METHOD FOR CONTINUOUS PULP PRODUCTION BY COLUMN-LIKE VESSEL TYPE CONTINUOUS DIGESTER

摘要

PROBLEM TO BE SOLVED: To prevent occurrence of chip hanging (unsmooth drop of raw material chip) during pulp production by a column-like vessel type continuous digester. SOLUTION: In the column-like vessel type continuous digester having constitution that in a vessel supplied with a ground lignocellulose substance and cooking liquor from the top part, a penetration zone A, a digesting zone B and a cleaning zone C are formed from the upper position, black liquor is extracted from an extraction strainer 4 arranged at the middle stage part of the vessel and a cellulose component is taken out from an outlet device 6 installed at the lower stage part of the vessel, the digester is equipped with an upper part circulation line L6for refluxing a part of cooking liquor from an upper part circulation strainer 2 laid at a boundary part between the penetration zone A and the digesting zone B to the top part of the vessel, a part of the liquor Z6is taken out from the upper part circulation line and sent to a recovery process line for cooking liquor so that a liquid ratio in the vessel is controlled and occurrence of chip hanging in the continuous digester is prevented. COPYRIGHT: (C)2005,JPO&NCIPI