Design, Developement and Evaluation of a Screw Feeder with Helical Mixer for Using in Triboaeroelectrostatic Mechanism

In this paper, a screw feeder with a helical ribbon mixer was designed and developed and evaluated for feeding Sisybrum seeds into a triboaeroelectrostatic mechanism for separating the impurities of fine grains. In order to check the feeding rates, the effects of rotational speed of screw in 3 levels of (60rpm, 90rpm and 120rpm), channeled plane outlet type in 3 levels of circle perforation with 4mm diameter, circle perforation with 6mm diameter and groove shaped with 5mm width and 280mm length and hopper location in 2 levels of (upside the conveying screw and upside the helical mixer) was investigated. The results was analysed on the basis of factorial experiment with randomized completely design. The results of comparing means based on multi-domain Duncan test showed that the most feeding rate is at the speed of 120rpm, groove shaped outlet and hopper location 2, and the least feeding rate is at the speed of 90rpm and hopper location 1. The most appropriate feeding rate for feeding Sisybrium seed into triboaeroelectrostatic by screw feeder is at the speed of 90rpm, circle perforation outlet with 4mm diameter and hopper location 1. The results by evaluating feeder operation on triboaeroelectrostatic mechanism showed that the feeder caused increasing material weight with the most purity (97%) and increasing separated impurity weight as twice as much of their amount without using feeder, by mixing material and charging them with static electric load.