... O-delignification stage, or among each bleaching stage. The equipment is featured unique design, stable operation, ... strainer washing zone. Filtrate collecting chamber at the end of drum directly connects to respective zone ... to 3rd, 2nd and 1st by turn. In the 1st stage strong black liquor enters black ... 16%. Residue liquor will be suctioned out from the pulp, so the pulp becomes cleaner. Then break-off ...