Process for Dispensing Contaminants in Waste Paper

摘要

1,194,705. Pulp for papermaking. LOWE PAPER CO. 15 May, 1967 [18 May, 1966], No. 22436/67. Heading D2A. [Also in Division B1] Contaminants in paper stock are dispersed in pressing a mass of wet pulp to a fibre content of at least 12% and exposing the mass to the vapours of a solvent for the contaminant at an elevated temperature so that the contaminants are softened and dispersed. Contaminants referred to are ink, bitumen, wax and pressure-sensitive adhesives; solvents are xylene, toluene, aromatic naphthas, esters, ketones and chlorinated hydrocarbons. As shown, apparatus for this purpose comprises a generally cylindrical vessel 108 with an entry port 100 and an exit port 105 at opposite ends, a shaft 106 mounted along the axis of the vessel, three screw flights 101, 103 and 104, all of substantially the same pitch, mounted in sequence along the shaft, with gaps 102 and 102' between each flight and the next, and ports 109 for introducing fluid into the vessel in a section corresponding with the second flight. In another embodiment (Fig. 3, not shown), the exit port of a generally cylindrical vessel of this kind is connected by a down leg with the entry port of a second cylindrical vessel a screw conveyor mounted on an axial shaft. There are several ports for introducing fluid into this vessel also. The screw flights in the second vessel are cut, and the speed of the motor driving them is variable, so that a head of paper stock can be maintained in the down leg. Hinged restricting gates are mounted on the exit port of the second vessel, and controlled by means sensitive to the pressure in the second vessel.