STUDY OF IMPACT ENERGY REQUIRED FOR EFFECTIVE

Abstract

This paper attempts to obtain the impact energy required for effective cracking of dried oil palm nuts to obtain high yield of whole kernels irrespective of the sizes and varieties. This is necessary because small scale farmers involved in cracking nuts do obtain nuts in most cases from processing of bulk nuts of mixed varieties. In this study, each variety (Dura, Tenera and Pisifera) of dried palm nuts were selected into classified size ranges based on their geometric mean diameter. Twenty-five nuts from each classified size range were picked randomly and mixed to form a group of nuts per variety. Ten groups and ten predetermined height drop of hammer mass were used per nut variety. Visual observations of cracking status after each nut has experienced hammer mass impact were assessed. In each group per variety, only energies that caused nuts to fully crack and release whole kernel were computed. For each variety, a plot of percentage fully cracked nuts in each group versus its corresponding average energy showed that impact energies of 2.6,1.82 and 0.97 Joules can crack well Dura, Tenera and Pisifera nuts respectively. The result further revealed that impact energy of 2.34 Joules was adequate to crack any of the nut varieties to release 91.5 percentages of whole kernels. This implies that cost in terms of time and energy for sorting; and identifying nuts into each variety and size ranges from bulk nuts of mixed varieties before cracking would be conserved.