The fundamental study on the reutilization of electronic scrap by passive pulsed air classifiers

As the electric and electronic technology being developed so quickly, the amount of electronic scrap (ES) becomes more and more enormous. The reutilization of ES is an urgent and challenging task achieved by adopting high efficiency, environmental friendly separation methods for reuse and recycle of electronic scrap. A practical and efficient separation method using passive pulsed air classifiers is introduced in this paper. In the pulsing air classifier, expansions and contractions separation of the throats impose a distance-varying airflow which alternately accelerates and decelerates the particles. Dynamics of the moving particles were analyzed by applying of advanced high-speed dynamic analyzing equipment. The ANSYS simulation results show that the accelerating region and symmetrical vortexes in the passive pulsed air separator are the basic reasons to achieve excellent separation based on density-dominant difference in passive pulsed air classifier. The results of the laboratory experiments indicate that the pulsing classifiers achieve more effective results of separation and get a wider range of operating velocities of the airflow than the non-pulsing ones. The acceleration and deceleration phenomenon of the air currents in the column of the passive pulsed separator provides a density dominant separation. It is concluded that this is favorable for electronic scrap processing.