REd dried chili peppers
Project undertaken in course year 2018-2019 with Precourt Institute for Energy
Project Goal
Develop a passively-drying racking system that is ergonomic for the users, structurally sound to maintain large numbers of chilis, and cost-efficient to maintain
Project Motivation
The goal of efficiently drying chili, and other foods, will reduce total food loss in this region, thereby improving the livelihoods of small farmholders and reducing food scarcity
Background
Drying chambers in Karnataka, India require better drying structures in order to provide uniformly dried chilis within a set time period that is ergonomic and cost efficient
The previous drying structure tended to break under continuous loads, was expensive as well as uncomfortable for the health of workers
existing racks deforming under load and temperature
High Priority Requirements
Chilis are uniformly dried in 3-4 days
The system costs less than $250 per 500 kg capacity
Racks are ergonomic to carry and load
Materials are food safe and operable in chamber conditions
Materials are locally sourced
Ethical Considerations
Production - food safe materials, waste management plan for system at end-of-life
Process - Equitable selection of farmers and operators, detailed hands-on training for safety of workers
People - prioritize user safety, respect local practices and community values
Solution
We developed a series of support structures and racks that enables easy insertion/removal of racks, while providing optimal placement of racks to exposure to even temperatures while ensuring they don't deform over time
Our final design is capable of holding up expected loads while under high temperatures and moisture content. Furthermore, the sliding feature improves the ease of use for the operators as this chamber is filled and emptied throughout the drying season
Rack system solution
Our racking system showing shelf structure, and racks carried within . Racks can be placed in from the side, sliding across rails
Existing Dryer
The dryer, scaled up to 500 kg capacity in India
Inside the Dryer
The current racks are stacked, shown in red, in the drying portion of the dryer
Airflow test setup
Test system developed to evaluate airflow across various configurations of shelf layouts
Shelf placements in Dryer
Top view of the dryer, showing the placement of shelving structures within for enhancing mixing of airflow as it moves across the racks, as determined by airflow testing
Chili racks on rails
The racks can slide in, on rails, to facilitate easy loading and unloading, and they don't rest on each other so don't deform
Other testing conducted
Deflection of structure under loads and temperatures
Strength of joints
Cost of materials to fabricate the system
Student team
Future Work
Iterate on door open/closing mechanism
Manufacture another prototype in India
More user/thermal testing
Create instructional vides on how to use product