Cleaning and Charging of Seeds with an Electrostatic Separator

Abstract

A belt-type electrostatic separator was constructed to grade seeds and remove impurities. The seeds are charged by the drum charger and the ionizing electrode stuck to the belt separates the grains via electrical attraction. The experiment used a factorial analysis based on a completely randomized design with three replications. Tests were conducted on wheat, barley, and canola seed. Two moisture levels for each seed type were used, storage moisture and storage +10% wet bulb. Three field voltage levels (8.5, 10, and 11.5 kV) were applied. Results showed that using the electrostatic separator had significant effects (P<0.05) on the purity and 1000-seed weight of all the seeds used. Maximum separation occurred at the low moisture for all grains using 11.5 kV for wheat and barley and 10.0 kV for canola. No separation occurred at the higher moisture content. Suitable voltages and moisture contents (w.b.) were found to be 11.5 kV and 6.7% for wheat, 11.5 kV and 6.3% for barley, and 10 kV and 3.5% for canola. The germination experiment showed that the electric field of this separator had no significant effects on improving the germination of wheat and canola but caused significant differences in germination percentages of sorted and unsorted barley seeds. The improvement gained in barley germination was 17.34% higher than that of unsorted seed.