Method and apparatus for improving the quality of paper manufactured

Abstract

An apparatus for improving the quality of paper manufactured from a contaminated fibrous stock having therein recycled paper pulp and contaminants smaller than a predetermined size and with a specific gravity approximately that of the specific gravity of whitewater used in the production of recycled paper stock comprises a hydrokinetic amplifier having a mixing chamber connected to each of a steam inlet, a stock inlet, a chemical feed inlet, an overflow discharge and a venturi. The venturi is connected to an outlet of the hydrokinetic amplifier. The apparatus also includes a pulper, a dump chest, a cyclone separator, a pressure screen, a vibratory screen, a holding tank, a pump, and various auxiliary pumps, valves, piping and sources of steam and whitewater. The method comprises mixing steam with contaminated fibrous stock in a mixing chamber to raise the pressure and temperature of the contaminated fibrous stock, mixing the contaminated fibrous stock with chemicals to promote emulsification of dispersed contaminants in the stock. The method further includes flowing the mixture of contaminated fibrous stock, steam and emulsifying chemicals through a venturi to apply cavitational forces to contaminants, to disperse the contaminants and produce contaminated stock having contaminants dispersed and emulsified therein and to increase the pressure and temperature of the contaminated fibrous stock from the pressure and temperature of the contaminated fibrous stock before being subjected to the method. The heated contaminated stock with the dispersed and emulsified contaminants therein is supplied to the pulper.