APS has Extensive Experience in Analysis and Improvement of Crushing and Grinding Equipment
- The Breakage and Selection functions (defined by Broadbent & Calcott) have been determined for various crushers (smooth, corrugated, slugger roll, over-head eccentrics and gyratory units). For given feed size distributions, these data enable one to write mass balance equations, that can be solved for circulating rates that include the effect of screen inefficiencies. These equations are most conveniently written as matrix form. The efficiency matrix is purely diagonal, while the Crusher data are lower diagonal matrices. Feed sizes are represented as vectors.
- As both participant and consultant to a multi-sponsor three-year research program, we formulated the residence time distribution in ball mills. These have since been verified in the doctoral dissertation of Soshi. We have been involved in the design, manufacture, research and operation of grinding mills.
- APS has tested most Screen-Separators manufactured, including Rhewum from Germany, Tyler from USA, Sweco and Kason rotary screens, and Orville-Simpson rectangular screens from USA. These tests have lead to "Efficiency curves vs. both particle size and loading" that determine the carry over of misplaced fines in closed crushing circuits. (enabling one to match the required Target mix requested by our client (such as Swiss Aluminum).
- APS has presented seminars on the subject of Air classification in graduate Seminars at Penn State University and has successfully analyzed Liquid cyclones for coal cleaning. We have made studies on classification of many materials with particles ranging from 2-4 microns to the larger 200 mesh particles (74microns), and have presented courses at the Center for Professional Advancement on this subject and for related courses such as Mixing of Particles. We have tested and can simulate most Air Classifiers from USA, Germany and Japan.
- It is interesting that the mass balance for each particle in a separation process satisfies the following expression, so that the right-hand side is a constant for all particles, and this constant is t/f, where f=p+t. These letters represent the scalars, t for tails, f for feed, and p for fine product. The capital letters T(x), F(x), and P(x) are for the corresponding cumulative size distributions (%passing).