Method of treating and a disperger for disintegrating wood pulp, especially containing waste paper

Claim 1

A dispersing system for treating a wood-fiber pulp which contains a recycled paper, the dispersing system comprising a pulp shredder, means for introducing steam to the pulp shredder, and a dispenser for finely-dividing the wood-fiber pulp containing the recycled paper, said disperser including; a) a housing (10a) having an inlet for the introduction of the pulp to an inlet zone in a substantially axial direction; b) a rotor (11) which in the region of the inlet zone carries pump-vanes; c) a disk (12) which is carried by the rotor and which has a peripheral section provided with teeth (12a) which co-act with opposing teeth on a ring or disk which is rigidly mounted, in the housing (10a), for finely-dividing the pulp; and d) a finely-divided pulp outlet 16 having a connecting piece (10b), said connecting piece (10b) having a substantially rectangular cross-section an inner measurement of said connecting piece corresponding approximately to the diameter of the rotor disk (12) and a total width of the disperser in the region thereof occupied by the toothed disks; said dispersing system further comprising a screw-press (20) which is connected to the connecting piece of the finely-divided pulp outlet and which functions to advance the pulp, without separate departure of steam, towards one end of the screw-press; said one end of said screw-press being closed by means of a valve device (21) such that the pulp will be compacted to form a plug seal in the vicinity of said one end of the screw-press thereby to prevent escape of steam from the dispersing system.

Claim 4

A method for treating wood-fiber pulp which contains a recycled paper, said method comprising the steps of: a) passing the pulp through a dewatering zone; b) delivering the pulp to a heating zone and advancing the pulp through said heating zone while supplying steam to said heating zone; c) finely-dividing the pulp in a disperser; d) delivering the finely-divided pulp from the disperser, without separate departure of steam, to a screw press of which one end is closed; and e) compacting the finely-divided pulp with the screw press so as to form a plug seal at said one end of the screw press thereby to prevent escape of steam from the screw press; wherein said one end of the screw press is closed by means of a counter-pressure exerting valve device; further comprising the step of opening said counter-pressure exerting valve device when a pressure exerted by the plug seal thereon exceeds a predetermined value; and further wherein said recycled paper is highly contaminated; and further comprising the steps of: regulating the pressure and temperature of the steam delivered to said heating zone and adjusting a counter-pressure exerted by the valve device depending on an extent of contamination of said recycled paper.

Claim 5

A method for treating wood-fiber pulp which contains a recycled paper, said method comprising the steps of: a) passing the pulp through a dewatering zone; b) delivering the pulp to a heating zone and advancing the pulp through said heating zone while supplying steam to said heating zone; c) finely-dividing the pulp in a disperser; d) delivering the finely-divided pulp from the disperser, without separate departure of steam, to a screw press of which one end is closed; and e) compacting the finely-divided pulp with the screw press so as to form a plug seal at said one end of the screw press thereby to prevent escape of steam from the screw press; wherein said one end of the screw press is closed by means of a counter-pressure exerting valve device; further comprising the step of opening said counter-pressure exerting valve device when a pressure exerted by the plug seal thereon exceeds a predetermined value; and further wherein said recycled paper is highly contaminated; and further comprising the steps of: regulating the pressure and temperature of the steam delivered to said heating zone and adjusting a counter-pressure exerted by the valve device depending on an extent of contamination of said recycled paper.