Search for Operating Conditions in the Thermal Pistachio Splitting in Fountain Confined Conical Spouted Beds

Abstract

AbstractThe worldwide consumption of pistachio nuts has been increasing over the last decades due to their high nutritional value. Given that only split nuts are commercialised, the closed-shell nuts, which account for most of the harvested ones, must be split by mechanical or thermal processes. However, there is hardly any information about the splitting mechanism based on thermal treatments. Accordingly, the thermal splitting of pistachio nuts in conical spouted beds has been approached, and the effect of the air inlet temperature, the draft tube aperture ratio and the air inlet diameter on the splitting mechanism has been analysed. Batch drying tests have been carried out in the proposed technology at an air inlet temperature range of 40–120 $${}^{\circ }\text {C}$$ ∘ C using configurations with and without draft tube. The operating temperature and dryer configuration that allows attaining up to 60% of split pistachios and preserving their quality are 80 $${}^{\circ }\text {C}$$ ∘ C , an inlet diameter of 0.05 m and an open-sided draft tube with an aperture ratio of 80%.