1. Team 6
Caleb Bruhn, Yifeng Hu, Sam Walby, and Alexis Wloch

2. • Problem Statement
• Design Criteria
• Gathered Information
• Design Alternatives
• Final Design
• Test Results
• Engineering Analysis
• Economic Analysis
• Conclusion
• Next Steps/Recommendations

3. • The country of Ghana has limited
nonrenewable consumables. Therefore,
there is a need for an effective method of
food preservation. A home-scale food
dehydration system powered on
renewable resources needs to be
designed.

4. • Total cost ≤ $50
• Suitable for mango and/or pineapple
• Output of 2 fruits/day or equivalent
• Lifetime ≥ 10 years
• Clean ≤ once/week
• 0 injuries/year to user
• Total system ≤ 5 feet x 5 feet

5. • No assembly required by customer
• Final moisture content of ≤ 25%
• “Home scale”
• Durable enough to withstand transport
• Quality of taste not compromised
• Powered by renewable resources

6. • Mango
o Mass: ~395
o Moisture content: 82%  25%
o Thickness: average of 1/8’’
• Required dehydration conditions
o Temperature: 130°F-140°F
o Time: 8-12 hours

9. • Acrylic dome
o Preferred over polyethylene
• Solar powered fan
• Anodized aluminum pan
• Mesh screens
• Metal tubing

11. Time
Mass
(g-mass of bag)
Temperature
(°F)
R.H.
(%)
Wind Speed
(mi/hr)
9:30 AM 294.9 44° 67 6
12:16 PM 242.1 45.6° 58.6 11
2:11 PM 210.8 49° 51 15.8
4:10 PM 175.7 48.2° 53.4 13.9
4:45 PM 167.9 48 53 14

12. • General model:
o f(t) = 2.247*exp(-0.1641*t)-1.249*exp(-0.2409*t)
• Goodness of fit:
o SSE: 0.0001506
o R-square: 0.9992
o RMSE: 0.01227
• Time required to
reach 25% moisture content:
o 32 hours in Michigan
o 9 hours in Ghana

13. Ideal Design
Components Bulk Cost
Aluminum Mesh $4.00
Clear Acrylic Dome $9.12
Solar Powered Fan $6.50
Anodized Aluminum Pan $22.32
Metal Tubing (legs) $6.18
TOTAL BULK COST: $48.12
Blue Skies Sale Price $65.00

14. Prototype Design
Components Company Cost
Aluminum Mesh *Alibaba $3.00
Plastic Lid GFS $1.99
Trash Can Lid Home Depot $7.00
Solar Powered Fan As Seen on TV $20.00
4 Wood Legs and 2 Wood
Braces
*Home Depot $2.72
14 Screws *Home Depot $1.20
1 Plastic Trash Bag *Meijer $0.30
Tape *Staples $5.89
J.B. Weld Glue Home Depot $6.12
TOTAL: $48.22
*= obtained from machine shop

15. • $0.70/lb of fresh fruit in Ghana
• One mango ~0.87 lb (395g)
• Blue Skies dried fruit $0.10/piece
• 28 mangoes needed every 2 weeks
• Assume 20 pieces per mango
• Consumer saves $7.80 by week 2
o Payback period = Less than 2 weeks
Each arrow represents a 2 week period
$56.00 $56.00 $56.00 $56.00$56.00
Purchasing dried fruit
$65.00
$17.05
$17.05 $17.05 $17.05 $17.05
Purchasing a dehydrator

16. • Assume ideal design would be successful
o Mass change in prototype
o Despite poor weather conditions
o Research revealed success in similar designs
• Economically feasible and beneficial

17. • Acquire ideal materials
• Design improvements
o Deeper aluminum pan
o Extra shelving space
o Improve stability
• Perform subsequent testing
o Correct weather conditions
o Uniform mango piece size
• Iterate optimization/testing

18. • "Accra, Ghana Climate Graphs." Climatemps. Web. 23 Apr.
2014.
• Blair, Ryan, George Calota, Adam Crossman, Finlay Drake,
and Kevin O'Keefe. "Design of a Solar Powered Fruit and
Vegetable Drier." Northeastern University.10 Apr. 2005. Web.
23 May 2014.
• Dissa, A. O. et al. “Convective Drying Characteristics of
Amelie Mango (Mangifera Indica L. Cv. ‘Amelie’) with
Correction for Shrinkage.” Journal of Food Engineering 88.4
(2008): 429–437. ScienceDirect. Web. 20 Apr. 2014.
• Dissa, A. O. et al. “Experimental Characterisation and
Modelling of Thin Layer Direct Solar Drying of Amelie and
Brooks Mangoes.” Energy 36.5 (2011): 2517–2527.
ScienceDirect. Web. 13 Apr. 2014.
• Glen, Chef. "Dehydrating Fruit." Backpacking Chef. Web. 23
Apr. 2014