Pecan Sheller Mockup ReviewStep 1A: FeedingStep 1B: Kinetic CrackingStep 2: ShellingStep 3: SeparatingCritical Module: ShellingEvaluation of Shelling ConceptsSlide 8Slide 9Slide 10Working ConceptSlide 12Pecan ShellerMockup ReviewGreen AStep 1A: FeedingFeeding and cracking are simultaneous processesLoading rate is limited by the time constraint of the cracker (6 seconds/pecan)Proposed method: vibratory bowl feederStep 1B: Kinetic Cracking26 pecans/minute in experiment by unskilled userRotating cylinder cracks the nut tips and shatters the shellAnvil automatically adjusts to any size nutStep 2: ShellingIndustry contacts have emphasized that shelling is the main problemNeed to maximize ratio of perfectly halved pecans to pieced pecansStep 3: SeparatingMust separate shell, packing material, and 2 kernel halvesPieces are low value: used in baking and confectionaryHalves are high value: used in candy and sold on their ownCritical Module: ShellingFigure 1. Distribution of Time to Process 10 Pounds or 250 PecansEvaluation of Shelling ConceptsBy Hand Rate26/minShelled100% (except those unshelled by cracker – if any)Halves100% (except those broken by cracker – if any)Pro Highest yieldConIncredibly SlowDollar Yield1.04 lb/min$8.32/minEvaluation of Shelling ConceptsShaking Rate40/minShelled100% (drill nut)70% (without)Halves5% (drill nut)75% (without)Pro Fast but damages halves with drill nut ConDifficult to reproduce motion, not FIFODollar Yield1.6 lb/min$12.80/minEvaluation of Shelling ConceptsTumbling Rate0.2/minShelled20%Halves100%Movie Pro Didn’t crush halvesConIneffectual, not FIFODollar Yield0.008 lb/min$0.06/minEvaluation of Shelling ConceptsAir Flow Rate0.25/minShelled10%Halves100%Pro Promising: used in industry on large-scaleConCannot be the singular shelling processDollar Yield0.01 lb/min$0.08/minWorking ConceptShear Rollers–Cracked pecans dragged along plate by gear teeth–Turning of gears shears off shell–Spring mounted base soft enough to avoid crushing meatWorking ConceptMechanical ShearingRate1/minShelled>5%Halves0%Pro Room for changes, optimizationConIneffectual, grinds nutsDollar
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