Separação e seleção de amendoim utilizando o princípio da velocidade terminal.

Abstract

This work had as a general objective, the determination of the physical properties, and aerodynamics of husk and seeds of peanut - variety L7, for future designs of machines and equipment to be used in the improvement processes; to develop and to evaluate an archetype of separation and selection of peanut using the terminal principle of speed and to determine the theoretical and experimental terminal speed of peanut - variety L7. The average results gotten for the physical features of several peanut sizes of the variety L7, had been: for husk, the biggest frequency of length, considering 75.8% of the sample, was verified to belong to the interval between 30 and 40 mm and 79.2% with diameter between 12 and 14 mm; the mass varied from 0.7377g to 0.8847g; the verified average volume, was between 11.159 and 15.181 mm3, the projected area displayed indices between 93.0465 and 135.0885 mm2, the roundness between 64.74 and 40.70% and the sphericity between 65.9952 and 88.1155%. For entire seeds, the biggest frequency of length, considering 48% of the sample, between 13 and 15 mm and 77.02% from 8 to 10 mm, for the diameter the gotten mass was between 0.3672 and 0.7468g, the volume between 3.394 and 7,0 mm3, the projected area between 12.4313 and 71.124 mm2, the roundness have gotten values between 51.75 and 71.55%and sphericity disclosed indices between 53.07 and 72.92 %. The wilted seeds brought out the biggest frequency of length between 12 and 14 mm (48.38 %), diameter between 5 and 7 mm (65.80 %), the mass between 0.2028 and 0,3787g, the average volume between 1.950 and 3.391mm3, the projected area: 12.43-71.12 mm2, the roundness: 22.61- "33.01 % and sphericity: 53.93-48.95 %. The damaged seeds had gotten mass between 0.0907 and 0.3552 g, average volume between 0.846 and 3.336 mm\ the projected area between 43.78 and 67.84 mm2, the verified roundness: 39.50-83.50 % and sphericity between 37.64 and 80.64 %. The porosity for the peanut was verified to be 44 % and the determined resting angle was 18°. The dragging coefficient considering all the sizes of peanut particles - variety L7, had varied between 0.17 and 0.48 excepting husks containing 2 seeds which brought out 3.91. The Reynolds numbers found for peanut, had varied between 6000 and 26000 in the amount of particle sizes found for the variety in study. The found experimental terminal speed for the entire seeds was between 12.39 and 13.80 m.s'1 and for husks: 9.30 - 9.40 m.s'1. The air stream, corresponding to the terminal speed brought out a turbulent system. The best way to separate the entire seeds from the damaged ones, wilted seeds and husks, was in fact using a speed of 15 m.s'1. This procedure achieved 67.3 % of success. This procedure didn't aloud a peanut seed selection according to size.