Study effects of moisture content, feed rate and fan revolution on separation efficiency in a paddy laboratory winnower

ABSTRACT: There are many methods in separating and grading grains and seeds in which mechanical and pneumatic methods are two important ones of them. Winnower is a pneumatic separator machine that separates whole seeds from hollow and damaged seeds. Using this machine compared with a mechanical system,leads to high separation efficiency, very low loss, low power consumption and also low cost which makes it economical. In this paper, effects of three independent parameters including two levels of moisture content (12%, 18% w.b), three levels of feed rate (13, 25, 32 kg/min) and three levels of fan revolution (850, 950 and 1150 rpm) in four replicationson separation efficiency were investigated. Lengh, width and height of this machine were 130, 30 and 117 cm, respectively. The obtained data were analyzed by Split-split plot test based on Complete Randomized Block. The mean effects were compared using Duncans-Multiple Range Test. For analysing variance of data, MSTATC package was applied. The test results showed that effects of moisture content, fan revolution and feed rate were significant. The maximum separation efficiency average allocated to 850 rpm. Effect of this level was different significantly compared with other levels. By increasing moisture content from 12 % to 18 %, separation efficiency average increased significantly. Also, by increasing the feed rate, the efficiency increased.