Jeffrey Perry and Dr. Randy Lewis, Chemical Engineering
Introduction
High in the Andes Mountains lives a group of Peruvians who spend their lives on the Uros Islands of Lake Titicaca. To purchase supplies at the nearest city, Puno, islanders must take a 20 minute motorboat trip and 10 minute taxi ride. Because trips to the city are infrequent, islanders rarely have the opportunity throughout the week to eat fresh baked breads, meats and desserts. The oven building team from the Global Engineering Outreach Class (GEO) at Brigham Young University decided to design, build and implement a portable oven, heated by propane that could be easily used and manufactured by those living on the Uros Islands. This specific project was recommended by the islanders and after seven months of brainstorming, prototyping, testing, and building, the team was able to present the design to the community on the Uros Islands.
Materials/Methods
Initial literature review and data collection for the project focused heavily on the behaviors, culture and needs of the people of the Uros Islands. The design was created using critical understanding not only of the environment and geography in which they live, but also the general practices and beliefs of the people1,2. The literature analysis conducted on this project ensured both the technical and cultural success of the oven. Key design aspects of the oven which required the most literature review included the importance of items like convection cooking, rack placement and typical oven gradient variances3. Major methods of literature review and data collection used throughout the project include the following:
• Interviews of professors, those who have visited the Uros Islands, and Peruvians who live on the Islands
• Online Blog which was created to share ideas and information with those in Peru
• Design reviews which allowed students, professors, and entrepreneurs to see the project and give feedback and recommendations
• Prototype construction and testing to find data on how well food could be cooked in a portable propane oven
The combined effect of these research methods allowed the design to be functional, sustainable, and culturally compatible in its intended setting.
Results and Discussion
Using the data collection methods detailed above, it was found that the propane burner provided much more heat than originally thought. On the low setting, the internal oven temperature for most prototypes ranged between 350 and 400 degrees Fahrenheit. On the high setting, the oven temperature exceeded 700 degrees Fahrenheit. Throughout these tests, it was discovered that temperatures usually varied no more than 100 degrees throughout the oven with the fuel setting kept constant. It was also found that cooking on high for an extended period of time would melt the aluminum bottom plate. After discovering this, galvanized steel was used in place of aluminum for the bottom plate. Because the range of temperatures found in the prototypes matched those of conventional ovens, it was determined that adequate cooking temperature would be easily attainable.
In addition to testing temperatures throughout the oven, a variety of foods including potatoes, cake, cookies, rolls, and chicken were cooked in the oven prototypes. Because of the small oven size and the significantly high temperatures, foods generally cooked a few minutes faster than those cooked with a conventional oven.
While determining the design of the oven, it was necessary to test whether a heat distributor or heat plate would be needed. One method in which the bottom plate versus no bottom plate designs were tested included cooking two batches of cookies simultaneously. The cookies in the oven without a bottom plate did cook faster, but the bottoms were burned. The cookies in the oven which contained a bottom plate cooked more evenly and did not burn. Thus, it was concluded that a bottom plate is necessary to more efficiently distribute the heat throughout the oven.
While in Peru, it was discovered that those living on the islands wanted to barbecue the chicken and duck instead of bake it. To accomplish this, the bottom rack was lowered so that it would be closer to the flames, as they wanted the flames to engulf the meat.
Conclusion
While in Peru, the initial feedback about the ovens was overwhelmingly positive. One month following the visit, an oven owner described how their family had been using the oven frequently to bake cookies, chicken, duck, and potato cake. Though challenges arose in Peru and the ovens required a significant amount of time to build, the team’s goals were met.
References
- Information. (2008). Retrieved June 6, 2013, from Lake Titicaca: http://www.laketiticaca.org/Information.html
- Uru People. (2013, February 25). Retrieved June 6, 2013, from Wikipedia: http://en.wikipedia.org/wiki/Uru_people
- Convection Oven. (2013, May 10). Retrieved June 11, 2013, from Wikipedia: http://en.wikipedia.org/wiki/Convection_oven