Pecan%20Sheller%20Mockup%20Review - PowerPoint PPT Presentation

Title: Pecan%20Sheller%20Mockup%20Review


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Pecan ShellerMockup Review

• Green A

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Step 1A Feeding

• Feeding and cracking are simultaneous processes
• Loading rate is limited by the time constraint of
  the cracker (6 seconds/pecan)
• Proposed method vibratory bowl feeder

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Step 1B Kinetic Cracking

• 26 pecans/minute in experiment by unskilled user
• Rotating cylinder cracks the nut tips and
  shatters the shell
• Anvil automatically adjusts to any size nut

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Step 2 Shelling

• Industry contacts have emphasized that shelling
  is the main problem
• Need to maximize ratio of perfectly halved pecans
  to pieced pecans

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Step 3 Separating

• Must separate shell, packing material, and 2
  kernel halves
• Pieces are low value used in baking and
  confectionary
• Halves are high value used in candy and sold on
  their own

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Critical Module Shelling

• Figure 1. Distribution of Time to Process 10
  Pounds or 250 Pecans

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Evaluation of Shelling Concepts
By Hand Rate 26/min Shelled 100 (except those unshelled by cracker if any) Halves 100 (except those broken by cracker if any)
Pro Highest yield Con Incredibly Slow Dollar Yield 1.04 lb/min 8.32/min
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Evaluation of Shelling Concepts
Shaking Rate 40/min Shelled 100 (drill nut) 70 (without) Halves 5 (drill nut) 75 (without)
Pro Fast but damages halves with drill nut Con Difficult to reproduce motion, not FIFO Dollar Yield 1.6 lb/min 12.80/min
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Evaluation of Shelling Concepts
Tumbling Rate 0.2/min Shelled 20 Halves 100
Movie Pro Didnt crush halves Con Ineffectual, not FIFO Dollar Yield 0.008 lb/min 0.06/min
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Evaluation of Shelling Concepts
Air Flow Rate 0.25/min Shelled 10 Halves 100
Pro Promising used in industry on large-scale Con Cannot be the singular shelling process Dollar Yield 0.01 lb/min 0.08/min
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Working Concept

• Shear Rollers
• Cracked pecans dragged along plate by gear teeth
• Turning of gears shears off shell
• Spring mounted base soft enough to avoid crushing
  meat

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Working Concept
Mechanical Shearing Rate 1/min Shelled gt5 Halves 0
Pro Room for changes, optimization Con Ineffectual, grinds nuts Dollar Yield Small