pecan sheller mockup review green a. step 1a: feeding feeding and cracking are simultaneous...
TRANSCRIPT
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
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
Step 2: Shelling
Industry contacts have emphasized that shelling is the main problem
Need to maximize ratio of perfectly halved pecans to pieced pecans
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
Critical Module: Shelling
Figure 1. Distribution of Time to Process 10 Pounds or 250 Pecans
6%
91%
3%
Feeding andCracking
Shelling
Separating
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
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
Evaluation of Shelling Concepts
Tumbling Rate
0.2/min
Shelled
20%
Halves
100%
Movie Pro
Didn’t crush halves
Con
Ineffectual, not FIFO
Dollar Yield
0.008 lb/min
$0.06/min
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
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