Physical-Mechanical Properties of Peanut (Arachis Hypogaea L.) for the Design of Flat Classification Surfaces

Resumo

The goal of the present work is to determine the physical-mechanical properties of Criollo variety of peanut kernels, required for the design of gravimetric classification machines. To fulfill the objective, the physical-mechanical properties of the peanut kernels of the most harvested variety (Criollo) in Manabí-Ecuador Province were determined. As physical properties, the dimensions of the grains, the equatorial diameter, as well as the specific and volumetric weight were determined. Static and dynamic friction and rolling angles were determined within the mechanical properties on four types of surfaces (carbon steel, stainless steel, wood, and rubber). The results allowed determining the dimensions of the peanut kernels m = 0,26 to 0,6 g; L = 10 to 15 mm; d = 5,50 to 9,1 mm. It was evidenced that the friction angle and the rolling resistance angle were higher in static cases on all surfaces investigated. Those of stainless steel and aluminum showed the lowest values of the static and dynamic coefficients of friction (ϕ=14,7 ± 0,07 αvδ ϕ d=13,5 ± 0,07 degree). The maximum values were observed on the rubber surface with ϕ = 35,7 ± 0,10 αvδ ϕd= 31,4 ± 0,13. The static and dynamic rolling angle showed a behavior similar to that observed in the friction angle, reaching maximum values in the rubber surface (α=26,0 ± 0,11 αvδ αd=24,4 ± 0,08 degree).