FIELD: bleaching of pulp by gaseous bleacher. SUBSTANCE: reaction vessel has a body with an inlet and outlet for cellulose particles and a means for cellulose feed, and flow of ozone-containing bleacher to the body. The means providing for movement of particles has a means for their raising, movement and repulsion in radial direction. At passage of cellulose particles through the body cellulose gets dispersed into ozone-containing gaseous bleacher. All surfaces of the greatest part of cellulose particles are subjected to action of the ozone-containing gaseous bleacher in the baffle condition, with the dispersion index being less than 8 for formation of essentially uniformly bleached cellulose. EFFECT: enhanced efficiency. 45 cl, 21 dwg , 12 tbl
