Plants for washing and defiberizing fibrous material

Claim 1

A PLANT FOR DEFIBERIZING, WASHING AND IMPROVING FIBROUS MATERIAL, ESPECIALLY RAW MATERIAL FOR PAPERMAKING. COMPRISING IN COMBINATION: A WATERTIGHT BREAKING CHAMBER OF THE HAMMER-MILL TYPE, SAID CHAMBER HAVING AN INLET PORTION, A ROTOR IN SAID BREAKING CHAMBER, HAMMERS PIVOTALLY MOUNTED ON SAID ROTOR FOR SWINGING IN PLANES PERPENDICULAR TO THE AXIS OF SAID ROTOR, MEANS TO INTRODUCE MATERIAL TO BE TREATED AND LARGE QUANTITIES OF WATER INTO SAID BREAKING CHAMBER, A LINING OF ABRASIVE MATERIAL IN AT LEAST A PORTION OF SAID BREAKING CHAMBER, MEANS ARRANGED AT THE LOWER PORTION OF SAID BREAKING CHAMBER TO DISCHARGE MATERIAL SUBJECTED TO THE COMBINED ACTION OF SHOCKS PRODUCED BY SAID HAMMERS AND HYDROKINETIC ACTION PRODUCED BY THE ABRASIVE LINING AND THE WATER, SELECTIVE MEANS DISPOSED TO RECEIVE MATERIAL FROM SAID LAST-NAMED MEANS, SAID SELECTIVE MEANS COLLECTING MATERIAL WHICH EXCEEDS PREDETERMINED DIMENSIONAL LIMITATIONS AND DISCHARGING ALL OTHER MATERIAL, AND MEANS FOR RECIRCULATING MATERIAL COLLECTED BY SAID SELECTIVE MEANS BACK TO SAID INLET PORTION OF SAID CHAMBER.