1 Development and Performance Evaluation of an Okra Seed Extractor

A prototype extractor was developed for extraction of okra seeds. Studies were conducted on effect of different cylinder speed (5, 6 and 7 m/s), concave clearance (7, 10 and 13 mm), moisture content of okra fruit (12.3, 15.8 and 18.8 % db) and type of extraction drum at a feed rate of 70 kg/h on machine performance and seed quality. Three types of extractor drums namely; square head bolted, rubberized and rasp-bar were used. Seed quality was evaluated for vigour index, dead seed, normal and abnormal germination. The performance of seed extractor was evaluated for its extraction efficiency, cleaning efficiency, seed loss and energy consumption at different crop and machine variables. Extraction efficiency (99.3%) caused by square head bolted drum was found highest among all the three extraction mechanisms. Cleaning efficiency was found in the range of 97.9 to 99.6 % for all crop variables. The value of seed loss (4.7 %) was low with the square head bolted drum in comparison to rasp-bar and rubberized extraction mechanism. The average energy consumption per quintal (100kg) seed was found to be 1.9 kWh. It was found that germination and vigour index decreased with increase in pod moisture content. Higher germination was found with square head bolted drum as compared to the rasp-bar and rubberized drum. The germination decreased, whereas dead seed percentage increased with cylinder speed. The best seed quality machine performance was found at 12.3 percent moisture content (d.b.), 7 mm concave clearance and 5 m/s cylinder speed with the square head bolted drum extraction mechanism