CONTINUOUS CELLULOSE FIBER MATERIAL COOKING DEVICE WHICH IS LESS COSTLY, REOUIRES LESS CONSUMPTION HORSEPOWER AND DOES NOT CAUSE PULP QUALITY DETERIORATION, AND OPERATION PROCEDURES

摘要

PURPOSE: To minimize mechanical actions on chips by making a slurry liquid of a cellulosic fibrous material in an impregnation vessel flow in an upward direction, placing the slurry liquid in a solid/liquid separator at the top of a digester and discharging the separated liquid through a liquid return conduit from the bottom of the digester. CONSTITUTION: A slurry liquid of a pulverized cellulosic fibrous material is fed through a conduit 31 and a high-pressure feeder 16 to the bottom of an impregnation vessel 34 and then made to flow from the bottom of the vessel 34 upward to the top. A part of the liquid is separated from the slurry at the top of the vessel 34 with a separator 36, subsequently made to flow through the interior of a liquid return conduit 41 in a digester 32 downward, then discharged to the bottom of the digester 32 and further returned to a high-pressure feeder pump 23 with a conduit 42. Chips are digested with a digesting liquid in the digester 32 and the produced pulp is then passed through a conduit 61 and withdrawn. At least a part of the digesting liquid is fed from a conduit 55 and introduced into a chip column at a point 56.