(167f) Breakage Distribution Functions in Fragmentation and Attrition

In process design it is desirable to model changes in particle shape as well as in particle size. While many mathematical models account for particle breakage occurring in various solids processing units, few models account for changes in the particle shape. For example, attrition models are often based on the assumption that only the corners of a particle are removed; and therefore there is little change in particle shape. Frequently breakage simulation has been limited to attrition only or fragmentation only. However, particle breakage in a stirred vessel can exhibit both fragmentation and attrition.

This paper presents breakage distribution functions for both fragmentation and attrition, where the breakage distribution functions include particle shape. These theoretically based breakage distribution functions account for changes in the mass, number, and shape of the particles. Simulation results are compared with experimental data from breakage in stirred vessels. This method allows for improved modeling of processes where both fragmentation and attrition occur by incorporating particle shape into the modeling of particulate processes. It is applicable to both batch and continuous processes.