Physical-Mechanical Properties of Peanut para el diseno de superficies planas de clasificacion

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 Manabi-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 ([empty set]=14,7 [+ or -] 0,07 [alpha]v[delta] [[empty set].sub.d]=13,5 [+ or -] 0,07 degree). The maximum values were observed on the rubber surface with [empty set] = 35,7 [+ or -] 0,10 [alpha]v[delta] [[empty set].sub.d]= 31,4 [+ or -] 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 ([alpha]=26,0 [+ or -] 0,11 [alpha]v[delta] [[alpha].sub.d]=24,4 [+ or -] 0,08 degree). Keywords: Classification, gravimetry, physical properties, mechanical properties, postharvest. El presente trabajo tiene como objetivo determinar las propiedades fisico-mecanicas de los granos de mani de la variedad Criollo, requeridas para el diseno de las maquinas de clasificacion gravimetrica. Para el cumplimiento del objetivo se determinaron las propiedades fisico-mecanicas de los granos de mani de la variedad (Criollo) mas cosechada en la Provincia Manabi-Ecuador. Como propiedades fisicas se determinaron las dimensiones de los granos, el diametro ecuatorial, ademas del peso especifico y volumetrico. Dentro de las propiedades mecanicas se determinaron los angulos de friccion y de rodadura (estatico y dinamico) en cuatro tipos de superficies (acero al carbono, acero inoxidable, madera, y goma). Los resultados permitieron determinar las dimensiones de los granos de mani m=0,26 a 0,6 g; L=10 a 15 mm; d=5,50 a 9,1 mm, se evidencio demas que el angulo de friccion y el