Impact velocity and compression force relationship — Equivalence function

Most of industrial processing units that deal with the handling of particulate materials (transporting, storage, size reduction, etc.) normally apply mechanical forces that cause certain amount of damage to the particles. In order to minimize or maximize the damage to the product material, one has to accurately calculate the loads being applied to the particles. Since in most cases common loads are impact or/and compression, it is essential to understand the relationship between them. The present study develops and validates an empirical function that calculates the equivalent force that causes the same percentage of the broken particles as if the particles collided with a certain impact velocity. The conversion of the impact load to the equivalent force enables us to compare various stressing conditions and thus to design and analyze a new operating unit with the same material regardless of the nature of the loads. The mathematical expression of the empirical equivalence function is similar to the micromechanical contact models. The parameters of this function result from the particle strength distribution and the impact breakage probability, which were determined by comparing the experimental data of impact and compression tests with salt, potash and GNP.

This work presents empirical equivalence model which calculates the equivalent force that causes the same damage to the particles as if the particles collided with a certain impact velocity. Proposed equivalence model enables comparison of the various stressing conditions and thus to design and analyze a new operating unit with the same material regardless of the loads nature.Figure optionsDownload as PowerPoint slideHighlights
► Description of the relationship between impact and compression systems
► Introduction to a test procedure for equivalence model development
► Development of equivalence model between impact and compression systems
► Comparison of the proposed model to the micromechanical contact one
► Model validation with the experimental data from three particle materials