CFD–DEM framework is applied here to describe the segregation patterns on a rice destoner. Commercial destoners have a rather simple design consisting of an inclined vibrating deck that is fed with contaminated granular material. Air is forced through tiny openings on the deck fluidizing the granular material above. The heavier contaminants (such as stones) are not fluidized and are carried to the higher side (steeper end) due to the vibrating action of the deck, while the fluidized (lighter) grains move towards the lower end of the deck and are collected there. A schematic of the rice destoner is provided. In order to minimize the computational effort needed to resolve granular flow patterns on a destoner, a symmetric transverse section is simulated. This work aims at developing a framework to study granular flow behaviour on gravity separators (such as the rice destoners) and a scaled- down simulation is a logical first step towards this objective.
A wide variety of machinery operating under the fundamental principle of separation based on "specific gravity or density" are available today and are widely employed in the downstream processing of food grains. The "rice destoner" is an example of one such equipment that is utilized in the preliminary stages of grain downstream processing to remove stone and other heavier contaminants from food grade grains. It is of common interest to obtain a fundamental understanding of the underlying phenomena of granular separation in order to develop smarter technologies for the cleaning of food grains.
To use adestoner fractionation process forseparating distillers dried grains with solubles (DDGS) into streams with various compositions. Results showed that destoner fractionation was somewhat efficient and effective. Runs with 8° angle and 27.5 percent air flow resulted in the highest value of protein and oil, which the light fraction had 28.15% protein, 10.50% oil, while the heavy fraction had 31.30% protein and 17.20% oil. P ... Читать далее