DEVELOPMENT AND PERFORMANCE EVALUATION OF PALM NUT CRACKER

Abstract

Palm nut cracking is an important process required during storage and processing of palm nut into different products. Due to the drudgery and inconveniences found in existing palm nut cracker, there is need for improvement. Therefore, this study was to develop and evaluate the performance of a palm nut cracker. This machine was fabricated in the Department of Agricultural and Environmental Engineering Workshop of FUTA with locally sourced materials. About 20,000 nuts were acquired, cleaned and sorted into various sizes. For every experimental run, 200 nuts were fed through the hopper to the cracker. After cracking, the number of whole kernels, broken kernels, partially cracked nuts, uncracked nuts and cracking time were recorded for further calculation. The machine was evaluated using five crop and machine parameters which includes; moisture (6.7 - 21.2% w.b), speed (970 - 2430 rpm), nut size (14.5 - 30.3 mm), palm nut variety (Dura and Tenera) and beater configuration (Rigid beater, RB; Serrated-swinging beater, SSB and Plain-swinging beater, PSB). The performance of the machine was determined based on four (4) variables whch includes: machine capacity (nut/h), quality efficiency (%), cracking efficiency (%) and mechanical damage (%). The experimental runs were carried out using completely randomized design (CRD) with 5 factor and 3 levels, the effect of operational parameters on the machine performances was determined using Analysis of Variance (ANOVA) in MS excel version 2016. The results show that the machine capacity, quality efficiency, cracking efficiency and mechanical damage ranged from 4,052 nuts/h to 21,351 nuts/h, 5.5% to 89.5%, 59.5% to 100% and 5% to 93% respectively for different varieties of palm nut and beater configuration. For Dura variety, machine capacity increased with decrease in moisture content, nut size and increase in machine speed for the three beater types. Mechanical damage decreases with decrease in machine speed, increase in nut size for all the beater configurations, and decreased with decrease in moisture content exceptfor rigid beater. Quality efficiency increased with decrease in speed and increase in nut size for all the three beaters but decreased with moisture content for swinging-serrated beater. For Tenera variety, machine capacity increased with decrease in moisture content and nut size and increase in machine speed for all the beaters, mechanical damage decreased with decrease in machine speed and moisture content for the beaters but increased with nut size except for plain-swinging beater. Quality efficiency increased with increase in nut size but decreased with moisture content and machine speed for the three beaters. Cracking efficiency increased with increase in nut size, moisture content and machine speed for all the different varieties and beaters. Change in machine speed had significant (P< 0.05) effect on all the performance parameters irrespective of the moisture content, size, variety and beater configuration. The obtained optimum machine performance value for Tenera variety were 14,874 nuts/h, 89.5%, and 100% for the machine capacity, quality efficiency and cracking efficiency respectively. The best crop and machine parameter for the optimum performance of the palm nut cracker are 14.7%, 29.43 and 970 rpm for moisture content (w.b), nut size and machine speed respectively using serrated-swinging beater with Tenera variety and 9.48%, 30.3 mm and 970 rpm for moisture content (w.b), nut size and machine speed respectively using rigid beater with Dura variety and this could be recommended for both small and large scale farmers.