Breakage Characteristics of Granulated Food Products for Prediction of Attrition during Lean-Phase Pneumatic Conveying

Pneumatic conveying is utilised in a variety of industries to convey food products exhibiting diverse handling characteristics. Attrition of particles caused by this conveying process can result in a number of undesirable outcomes such as loss in product quality or issues in subsequent handling processes. The ability to predict the breakage behaviour of particulate materials is desirable in both new system design and resolving issues in existing plants. This work considers two different particulate materials (Salt and Golden Breadcrumbs) across a range of particle sizes, and quantifies their breakage behaviour under varying impact conditions. Narrow size fractions of each material were degraded; material retained on 250 mu m and 355 mu m sieves for Salt, and 500 mu m, 710 mu m and 1,000 mu m sieves for Golden Breadcrumbs. Velocity was found to be the most influential factor with respect to particle attrition. The results from the narrow size fraction tests were superimposed to form a simulated full size distribution breakage behaviour, which was then compared to the experimentally determined behaviour. A good agreement was found, however the proportion of material predicted for size fractions smaller than 355 mu m for Golden Breadcrumbs and 180 mu m for Salt was under-predicted. Recommendations for increasing accuracy of the prediction method are given.