Detailed Design Review Solar Transpired Collector Crop Dryer P17483 December 8, 2016

Team Introductions Team Member Major Role Caly Evans Mechanical Engineering Project Manager Matt Hossack Louie Kline Kaleigh Sweeney Industrial Engineering Kelsey Clements Caly

Agenda Current Problem CRs and ERs Designed Components Trays Drying Chamber Solar Collector Chimney Proposed Bill of Materials Testing Plan Limiting Operator Error Risk Assessment MSD II Plan Schedule, Design, Test Plans,

Problem Statement Current State Desired State Project Goals Previous designs developed which are functional but not suitable for construction in Haiti Desired State A robust prototype made of area-appropriate materials, capable of drying moderate amounts of fruit in a few days Project Goals Analyze current designs Identify opportunities to: Increase temperature Increase airflow Constraints Materials must be available in Haiti Food safety Budget Kelsey

Customer Requirements

Engineering Requirements Rqmt. # Engineering Requirement (Metric) Unit of Measure Ideal Minimum In Design ER 1 Moisture content of fruit Weight % <10 <15 15% ER 2 Quantity of dried fruit Kilograms/Day >10 >5 8 ER 3 Percent of materials in contact with food that are food grade % of Surface Area in Contact with Food 100 100% ER 4 Fruit meets food and safety specifications Bacteria/Sq. inch * In progress ER 5 Time to dry fruit Hours <24 17 hours ER 6 Payback time Months <12 ER 7 Cost of materials Dollars <50 <100 ER 8 Tools required for assembly/disassembly # of Tools 1-3 In design ER 9 Reading level for instructions Reading Level # No reading required <2 N/A

Engineering Requirements Rqmt. # Engineering Requirement (Metric) Unit of Measure Ideal Minimum In Design ER 10 Time for disassembly Minutes <45 <90 N/A ER 11 Number of imported materials # materials 0-1 <5 2 ER 12 Footprint size Ft x ft x ft <9x5x4 8 x 4 x 3 ER 13 Time spent attending to the device during operation <10 ER 14 Number of steps to initiate drying steps # of Steps TBD ER 15 Part replacement rate Parts/month 1-2 ER 16 General maintenance frequency Times/week <3 ER 17 Withstand high wind speeds Wind speed mph >45 >30 ER 18 Water drainage time <1

Tray Concept 6 packs of 6 stacked trays Full frame on bottom tray Parallel side pieces on trays 2-6 Square for alternating directions.

Tray Concept Continued Base tray

Chamber Size 16” tray 20” tray 0.035 mair ave. [kg/s] 0.044 20.0 ΔT [C] 19.2 5.94 Mass remov. [kg] 6.77 (Same total mass of bananas split between trays.) 21” x 63” internal chamber size (16” sq trays) 25” x 75” internal chamber size (20” sq trays)

Insulation Calculations - Straw/Grass Thermal resistance of tarp and corrugate metal were negligible. Thermal loss calculated using predicted temperature increase. Wall diagram:

Drying Chamber Door Side

Drying Chamber - Front View

Drying Chamber - Bottom View

Drying Chamber - Right Side View

Collector Size 8 ft 4 ft 3 in

Collector Size Justification Energy required to remove necessary water. Average necessary mass removal rate, over 2 days Dryer efficiency, based on average mass flow rates. Promising value, as Dr. Steven’s dryer ran around 55-60% efficiency

Collector Size Justification Energy required accounting for drying chamber efficiency. Estimate collector efficiency, calculated collector area needed for energy absorption. Our collector, approximately 72% greater area.

Collector Matlab Results 6’x6’ 8’x8’ 0.024 mair ave. [kg/s] 0.044 19.4 ΔT [C] 19.2 4.34 Mass remov. [kg] 6.77 ~ 6’ x 6’ collector ~ 8’ x 8’ collector

Chimney The chimney will run the entire length of the drying chamber, approximately 75” long. Vent locations Matlab simulations were performed on widths from 2” to 12” < 6”, air flow rates (and performance) dropped > 6”, little to no change, will not make it larger because we would need more roof material. Additional solar heating was added to the model, which increased air flow nearly 50% ~ .05 kg/s to ~ .08 kg/s

Non-Heated Chimney vs Heated Small rect. duct, no heat 6”x75” 12” h, w/ heat 0.044 mair ave. [kg/s] 0.076 19.2 ΔT [C] 16.8 6.77 Mass remov. [kg] 7.64

Final Proposed Design

Bill of Materials Team Haiti We want to try other materials for the back of the collector because plywood is very expensive in Haiti Last review our material cost was over $415

Test Plan Description Planned Date Intended Result ERs Addressed 1 Test the tray packs inside the cardboard enclosure MSD II, week 1 To know the best tray spacing and location within the drying chamber moisture content of fruit 2 Test the differences between doing 4 pack and 6 pack. evaluate drying based on fruit spacing on trays 3 Dryer/chimney assembly, indoor with simulated environment MSD II, weeks 5-6 Preliminary evaluation of drying capability of full system. moisture content, time to dry fruit, human-device interaction during operation, number of steps to initiate drying 4 Full system assembly, with collector, ideally outdoor MSD II, weeks 8-11 evaluate full system, with mass removal, air flow, temperature and humidity measurements 5 Weather testing (water resistance) Evaluation of reasonable rain resistance of system, add weatherproofing as needed. water resistance and drainage, general maintenance 6 Assembly test with volunteers MSD II, week 12 Finalize assembly and operation instructions Reading level of instructions, tools required

Limiting Operator Error Uniform thickness of fruit slices: We will be making our own banana slicers (wood frame with wire strung through holes) to slice entire fruit at once. We also plan to put thickness indicators on the side of the drying chamber. Tray Assembly: The square base allows users to put the mesh trays on any direction, although directions will be provided for the preferred orientations. Picture/photo-based instructions.

Risk Assessment 9 9

MSD II Plan