A framework for the description of multidimensional particle separation processes
Thomas Buchwald, Edgar Schach, Urs A. Peuker
Abstract
Most unit operations that separate or sort particle collectives according to a primary property – like size or density – show the tendency to have their separation efficiency being influenced by one or more additional particle characteristics like shape or surface area. While many of these multidimensional properties of a separation process have been acknowledged, they have yet to be properly investigated. A framework is presented in which a separation process can be analyzed in two or more dimensions, i.e., along two or more characteristic particle properties. Examples of possible separation results are given and some ways to describe the separation efficiency in multiple dimensions are explained. While it is straightforward to extend the analytical expressions for grade efficiency to multidimensional problems, descriptors for separation efficiency like separation sharpness prove to be less useful. Entropy is shown to be an accessible alternative for the description of separation efficiency.