FROTH FLOTATION APPARATUS AND METHOD

摘要

BKS 188/194 P2 Apparatus for separating contaminant particles from liquid suspension stock, e.g. in the de-inking of used news print, is characterized by one or more of a plurality of features which contribute to increasing the capacity and effectiveness of the apparatus, including the provision of a cell comprising inner and outer annular chambers of substantially equal depth with the inlet and outlet connections for the stock being located adjacent the bottoms of the two chambers to force the stock to travel through the full depth of each chamber, and also the provision of a baffle of substantial width on the top of the wall between the two chambers to spread the stock overflowing that wall into a thin film. Other features include the use of an explosion-type flowbox to aerate the stock as it is delivered to froth flotation apparatus, and an alternative aerating device comprising a drum-shaped rotor having an irregular outer surface which is positioned in the stock inlet conduit leading to the cell on an axis extending transversely of the conduit, a nozzle positioned to direct a supply of air against the rotor surface on the upstream side of its rotational axis, and a drive causing the rotor to rotate at a linear speed of its outer surface which is substantially higher than the linear flow rate of the stock in the conduit so that the rotor surface breaks up the air impinging thereon into bubbles and distributes those bubbles in the stock flowing therepast to create foam within the cell.