Patent ID: 6340409
Filing Date: 2002-01-22
Classification: D21C

Abstract:
A method for transporting pulp from an initial gaseous bleaching stage to subsequent bleaching stages, comprising the steps of:supplying a medium consistency pulp to a pulp contactor apparatus included in the initial gaseous bleaching stage which comprises an ozone bleaching stage; delivering to the pulp contactor apparatus a gaseous bleaching reagent at a predetermined pressure; maintaining the pressure of the gaseous bleaching reagent within the pulp contactor apparatus; discharging the medium consistency pulp from the pulp contactor apparatus under said gas pressure; using the gas pressure maintained by the pulp contactor apparatus as the motive force to transport the medium consistency pulp and the gaseous bleaching reagent to at least an immediately subsequent bleaching stage; disposing a mixer between the initial gaseous bleaching stage and the immediately subsequent bleaching stage; and releasing a portion of the gas pressure from said mixer to reduce the quantity of the gaseous bleaching reagent carried forward to the immediately subsequent bleaching stage.