ADVANCED SYSTEM AND METHOD OF RECYCLING FILTRATE OF CHEMI-THERMOMECHANICAL PULP Russian patent published in 2014 - IPC D21C11/00 

FIELD: textiles, paper.

SUBSTANCE: method of manufacturing bleached pulp comprises contacting the mixture of brown stock with a first circulating filtrate to obtain a first mass mixture having the first consistency; bleaching the first mass mixture to obtain the first bleached pulp mixture; squeezing or dewatering the first bleached pulp mixture to obtain the first mixture of bleached pulp and the second filtrate; direction of part of the second filtrate into second place of the first contour of recycling filtrate; contact of the first mixture of the squeezed bleached pulp with the second circulating filtrate obtained from the third place of the first contour of recycling filtrate to obtain a second mass mixture having a second consistency, and the second consistency is higher than the first consistency; bleaching the second mass mixture to obtain the second bleached pulp mixture; squeezing or dewatering the second bleached pulp mixture to obtain the second bleached pulp mixture and the third filtrate; direction of part of the third filtrate into the fourth place of the first contour of recycling filtrate; recycling at least a part of the third filtrate in the first contour of recycling filtrate to the first place; to obtain the bleached pulp. At that the first, second, third and fourth places of the first contour are in fluid communication and downstream relative to each other.

EFFECT: increased strength properties and brightness of pulp is provided.

68 cl, 1 tbl, 13 dwg