International Journal of Agricultural Policy and Research
Vol.3 (8), pp. 323-327, August 2015
Available online at https://www.journalissues.org/IJAPR/
Article 15/ID/JPR61/05/ pages
Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License.
Original Research Article
Effect of rotor speeds of centrifugal palmnut cracker on the characteristics of the constituents of the crack mixture
Okokon F.B., *Okoko P., Akanga A., Umani K., and Obot N.
Department of Agricultural and Food Engineering, University of Uyo, Uyo, Nigeria.
*Corresponding Author Email: firstname.lastname@example.org
Separation of kernel and shell particles in a cracked mixture is a challenging process due to close relative sizes of the constituents. Samples of mixed varieties of ready- to-crack palm nuts at 7.82% mc (w. b) were cracked in with a centrifugal nutcracker at rotor speeds of 1760, 1891, 2068, 2175, 2250, 2450, 2650, 2800, 2962, 3150, 3300, and 3450 rpm with two replicates. The constituents of the cracked mixtures were separated manually, counted and weighed. The axial dimensions of the whole kernels obtained in each run were measured and used to determine the geometric mean diameter (GMD).The shell particles were subjected to particle size analysis and the results used to determine the geometric mean diameter and standard deviation of the shell particles. The results showed that the unit mass of shell particles decreased from 0.37 to 0.07g with increase in speed compared to kernels (0.65 to 0.80g). The GMD of the shell particles decreased from 11.09 to 5.72 mm compared to kernels (10.97 to 12.97 mm). The cracking efficiency increased from 37.5 to 98.0%, the percentage of broken kernels to total kernel product increased from zero to 19.2%. The findings showed that to limit the percentage of broken kernel to the total kernels production at 10%, the rotor speed was found to be at a range of 2800 to 3150 rpm, cracking efficiency 90.5 to 98%, unit mass of shell particles (0.08 to 0.11g) and GMD (6.34 to 7.73 mm)
Key words: Palm nuts, cracked mixtures, kernels and shell particles, geometric mean diameter.