Cocoa Bean Sizer System

Team: Sage Hill, Drew Larkin, Landon Morgan, Zachary Smith, and Benjamin Stucki

Sponsor: Aggie Chocolate Factory

Project Description

The Aggie Chocolate factory obtains cacao beans from multiple sources such as Brazil, Ecuador, and the Dominican Republic. Due to these various sources, cacao beans come in varying sizes from large to small. Because the Aggie Chocolate Factory values producing quality products, they requested a machine that is capable of sorting beans by their thickness. This is important because having beans of the same thickness allows for a better roasting process and therefore higher quality chocolate.

Customer Requirements

  • The customer has listed several requiremeents for hte desging process.
  • The design should be easy to clean and maintain
  • Must be able to adjust to be able to sort varied sizes of beans
  • Maximize visibility to visible to tour participants
  • The design must sort beans accurately into at least two groups
  • Minimize cost of machine
  • Minimizes Jamming
  • Adjustable feed rate of beans into the sorting mechanism

Customer Constraints

  • The customer has listed several constaints for the design process.
  • The size of the device/machine must not exceed 2' x 8' of 16 sq. ft
  • The design must utilize 3-phase, 208-volt, 20-amp circuits
  • The design must require no major maintenance besides basic cleaning and lubrication
  • The design must utilize metals, plastics, or ceramics only
  • The design must sort 40 kg of beans per day
  • The design needs to be able to fit through a standard sized door
  • The design must be easy to load via bins by trained workers
  • Needs to be fully automated

Design Description

  • The hopper stores unprocessed beans to be sorted.
  • The auger then carries the beans to the table to be sorted.
  • The sorting table separates beans by height by deflecting larger beans with a rotating rod.
Design Description 1
Design Description 2
Design Description 3
Design Description 4
Conventional Choclate Process

Conventional Choclate Process. Cacao Pods -> Pulp/Beans -> Fermentation -> Drying -> Roasting -> Winnowing -> Grinding -> Sterilisation -> Milling -> Conching

Performance Review

Performance Review
Functional Requirements and Constraints Units Threshold Target Predicted Performance Actual Performance
Low Jamming Frequency Jams/day 1 0.15 0 0
High Feed Rate Resolution Beans/min 10 5 8.5*E-4 0
Low Cleaning Time Hours to Clean 8 3 2.5 0.5
High Sort Size Resolution mm 1 0.5 0.1 0.1
High Sort Size Range mm 2 10 250 250
Low Rate of Bean Sorting Error % Beans in correct bin 10 2 2 9
High Amount of Visible Components % of machine 20 50 75 90
Low Cost $ 2000 1750 1540 2000
Sorting Rate kg/day 40 40 40 19.7

Conclusion

Candy bar
  • The produced machine meets all requirements except the sorting rate and feed rate resolution. The feed rate resolution is not necessary due to the wide variety of low-speed motors. The sorting rate requirement can be met by buying a new auger motor with higher speed (ideally about 40 rpm).
  • Lessons Learned
    • We learned that it is best to fail fast and fail often to iterate our design efficiently.
  • Recommended Future Work
    • Enhance sorting accuracy through infrared cameras or lasers
    • Optimize mechanical components by upgrading motors or other electrical components
    • Create a computerized UI that controls the machine, tracks accuracy, and can be monitored from a distance.
    • Optimize energy efficiency by using more efficient motors, LEDs, or other components.