DIRECT INJECTION VERSUS DYNAMIC MIXING: A MILL SCALE COMPARISON OF MEDIUM-CONSISTENCY MIXING TECHNIQUES FOR OXYGEN AND STEAM. .

A cooperative study was conducted of direct in-line injection for mixing oxygen and steam in the E//o stages. On the E//o stage of line 'A', the dynamic mixer was bypassed and an injection system was installed after the medium-consistency pump. The line 'B' stage was left unchanged and used as a control case. Direct in-line injection of oxygen and steam proved to be an efficient alternative to the use of a dynamic mixer for oxidative extraction and steam/heat transfer. Power and steam consumption on line 'A' were substantially reduced, while pulp brightness and quality remained very similar to line 'B'. The injection system is still in operation on line 'A' and permanent modifications will be made on both E//o stages to eliminate the dynamic mixers.