Multiphase flow characteristics of gas sparged hydrocyclone flotation deinking

A new high-efficiency technology has been developed for flotation deinking of various wastepaper grades. The GSC gas sparged hydrocyclone is a centrifugal device that operates at consistencies of 1 to 3 percent and uses conventional flotation chemistry. Research and development efforts have continued in order to better understand the fluid mechanics involved in successful air-sparged hydrocyclone flotation deinking. X-ray computed tomography measurements have helped to describe the multiphase fluid flow in the hydrocyclone, particularly with respect to particle segregation in the swirl flow. This measurement technique has also been used to evaluate the characteristics of the froth phase. Additionally, bubble size distributions generated during operation of the hydrocyclone have been measured using a special photographic technique. The results of these research efforts will be presented and discussed.