METHOD FOR PRESSURIZED PEROXIDE BLEACHING
The present invention relates to a method for safely carrying out pressurized peroxide bleaching of pulp, at a consistency exceeding 8 %, preferably 10-16 %, in a bleaching vessel (1), designed for at least 0.5 MPa overpressure, preferably 0.7 MPa overpressure, with the pulp being fed to the vessel (1) by means of a pump (2), preferably a pump having fluidizing elements and venting, and with the pulp which is being fed to the vessel having a temperature exceeding 90 DEG C, preferably exceeding 100 DEG C, more preferably exceeding 105 DEG C, and with the pulp being bleached with peroxide in a quantity exceeding 5 kg/BDMT, preferably in association with a bleaching stage which bleaches the pulp to a brightness exceeding 75 % ISO, characterized in that if plugging and/or power failure occur(s), measures are taken, essentially without using mechanical safety valves, which prevent the pressure in the said bleaching vessel, or an affiliated part, from being allowed to exceed a certain set point.