Performance Evaluation of a Dehusking and Shelling Machine for Castor Fruits and Seeds

Abstract

The performance evaluation of a locally developed castor fruits and seeds dehusking and shelling machine was carried out. The development of the machine was embarked upon in order to reduce the drudgery associated with the processing of castor oil. The machine consists of two major compartments, the shelling unit and the dehusking unit. A blower was incorporated to facilitate easy and proper cleaning and separation of the seeds from the chaffs. Performance tests were carried out using two different accessions of castor seeds (the large and small castor seeds at three different drum speeds of 240 rpm, 320 rpm and 400 rpm, using 1000 g, 2000 g and 3000 g of both castor seeds, each one replicated three times. The results show that the shelling efficiency and seed recovery rate of the machine decreased as the speed of the drum increases (at 240 rpm-80.34 % and 99.50 %), respectively and at 400 rpm-76.28 % and 99.18), respectively, while the percentage losses in seeds, cleaning efficiency and mass flow rate of the material increased as the speed of the drum increases (at 400 rpm-0.98 %, 51.23 % and 23.18 g/s and 240 rpm-0.50 %, 50.63 % and 15.21 g/s), respectively. The results of the ANOVA indicate that the shelling efficiency of the machine differs significantly at the three drum speeds. The analysis also shows that the machine performed better at 240 rpm compared to the other two speeds. It can be concluded, that the developed machine could reduce the drudgery involved in manual shelling with saving in operating time of about 70 %.