Mathematical modelling of heating uniformity for in-shell walnuts subjected to radio frequency treatments with intermittent stirrings

摘要: Non-uniform heating caused by the different orientations and locations of in-shell walnuts may be a major problem in developing large-scale radio frequency (RF) treatment for postharvest phytosanitary quarantine regulations international trade. A mathematical model was developed based on normal distributions walnut temperatures against to study influence number RF units intermittent stirrings uniformity. The validated experiments with good accuracy. It determined that rise standard deviation at any time during increased linearly mean temperature. ratio, defined as uniformity index, depends upon design unit, has significant needed achieve desired insect mortality. For index value 0.165, minimum two meet temperature controls, such lowest 48 ◦ C 67 99.9968% mortality or 50 64 99.9%