Aerodynamic Vectoring Particle Sorting

An experimental and numerical demonstration of a new, non-contact particle sorting technique called Aerodynamic Vectoring Particle Sorting (AVPS) is presented. AVPS uses secondary blowing and suction control flows to sharply turn a 2D, particle-laden jet. As the jet is turned, the inertia of particles present in the flow is balanced by a resultant force that is dependent upon their size and due to the combined effects of pressure, and drag. Since the balance of these forces determines the particle’s trajectory, turning the flow leads to a separation of particles downstream. This simple, low-pressure-drop sorting technique classifies particles with less risk of damage or contamination than currently available sorting devices. AVPS is experimentally demonstrated using a rectangular air jet. A single blower is used for the blowing and suction, thus requiring that their mass fluxes are equal. The unladen jet flow is examined using Particle Image Velocime-try. The experimental results demonstrate that while large blowing slot momentum flux is important (meaning that a smaller slot can be more effective for fixed mass flux), as the aspect ratio of the blowing slot becomes very large, the jet tends to suffer from 3-D instabilities resulting in large fluctuations in the vectoring angle (and thus a detrimental effect on sorting performance). The vectoring angle can be substantially improved introducing a modest angle in the blowing slot (toward the vectoring direction). Particle size and trajectory are measured using the Particle Shadow Imaging method. Numerical simulations are performed using a commercial CFD solver.