COLD BLOW BATCH COOKING PLUS MEDIUM CONSISTENCY OXYGEN - HEAT-EXCHANGER PLACEMENT

Stage-2 rapid displacement heating pulping using digester pump-out and oxygen delignification in combination with a fully counter-current cl osed liquor system extends delignification in the closed part of a mil l to reduce the discharge of chlorinated organic matter in the bleach plant effluent. Operation requires excess heat removal to keep the dig ester pump-out, decker dropleg, and medium consistency pump temperatur es under control at different operating conditions. Computer simulatio n analyzes heat exchanger locations to control the critical system tem peratures.