Abstract
The first part of the present study deals with some physical and mechanical properties for sunflower seeds components (seeds, hull's and kernels) related to pneumatic separation which are evaluated as a function of change in moisture content from 8 % to 14 % (d.b). Simple linear empirical equations were developed to predict sunflower seeds components properties according to moisture content. All dimensions, mass, angle of repose, coefficient of fraction, and terminal velocity increased linearly with the moisture content increased up to 14 %, while the bulk density decreased linearly with the moisture content increased The second part was carried out on a series of experiments to specify the optimum conditions of separating operation which ensure the highest grade of separation efficiency with minimum losses. The combination of air velocity, feed rate, percentage of broken kernels and moisture content affected significantly the separation efficiency and kernel losses. Air stream velocity of 3.5 m/s combined with 30 kg/h feed rate, 10 % broken kernels and (10 - 12 %) moisture content can be considered the most favorable combination values of these variables to obtain the highest separation efficiency with minimum kernel losses.