Understanding the flow properties of bulk solids (potash, limestone, salts, etc.) is important for determining the optimal design of bins, hoppers, and silos in an industrial process. Lab testing of a bulk solid’s cohesive shear strength, as well as its wall friction properties allows engineers to properly design the aforementioned containers.
ADMET worked with a customer to develop a test machine solution that is adapted from “ASTM D6128 – Standard Test Method for Shear Testing of Bulk Solids Using the Jenike Shear Tester”. This test standard accounts for a vertical normal force (to pack the bulk material tightly into a cylindrical shape), and then a horizontal load application to measure shear properties of the consolidated material. There are methods for testing both the cohesive shear properties of the bulk solid itself, as well as its friction properties against various other materials intended to be used for container walls.
The customer’s main issue with existing test equipment available on the market was that it was not very repeatable, especially at lower loads. ADMET’s solution leveraged its existing eXpert 5600 actuator and eP2 Controller technologies to create a bi-axial system that could be easily controlled by the user and provide very precise and repeatable results. The solution also eliminated the need to use a dead weight stack for material consolidation prior to and during testing. Load cells are applied in both the vertical and horizontal load trains that allow for accurate measurements even at the low end of typical test ranges.