Dissolved solids control in pulp production

摘要

A hydraulic continuous digester assembly comprises an upright continuous digester (11) having a top and a bottom; an inlet (22), for a slurry of cellulosic material to be digested, at the top of said digester (11); an outlet (23) for digested pulp at the bottom of said digester (11); a first screen assembly (30) located below the top of said digester (11); a second screen assembly (31) located below said first screen assembly (30) in a cooking zone; means (34) for extracting a first liquid from said first screen assembly (30); means (39) for recirculating a first portion of liquid withdrawn from said second screen assembly (31) into the interior of the digester (11) at about the level of said second screen assembly (31) in the cooking zone; means (52) for adding dilution liquid into said first portion of liquid being recirculated in said recirculating means (39); and an extraction screen assembly (32, 33) below said second screen assembly (31).