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Small Parabolic Cooker for Jefferson Community Center
Senior Environmental Science Majors Nick Hurn and Kevin Burks are creating a small parabolic mirror cooker to demonstrate the wide uses of alternation energy in Humboldt County. It is part of an Spring 2013 ENGR305 class at Humboldt State University and will be featured on permanent display at Jefferson Community Center in Arcata, California. Parabolic cookers are designed to harness the sun's energy and transfer it directly into the process of cooking raw material. It will serve as a functioning solar cooker for lunches and activities for the students and staff as well as an example of a creative use of alternate energy for the community to enjoy.
The object of this project is to create a parabolic mirror cooker that is a successful example of the ways to capture and use the sun's energy in a sustainable manner. We plan to do this in two steps by first testing the most efficient and effective way of building the cooker, then implementing the most environmentally friendly construction techniques to achieve the creation of it.
Project Evaluation Criteria
The following Criteria will be used to assess the success of this project. After deliberation with the client, we determined the following criteria to be critical for the success of our project. The 1-10 scale signifies the importance of each listed criteria.
|Functionality||The cooker must reach an optimal temperature (TBD) within a certain time (approx. 2 hours)|
|Ease of Use and Safety||Design must be straightforward and child-friendly|
|Educational Value||The cooker must effectively demonstrate the power of alternative solar heating|
|Placement and Storage||Cooker must fit into a designated storage area (approx 4 ft. square) and fit through specified double doors|
|Size||Must be big enough to effectively cook food in relatively short period of time while still maintaining mobility|
|Mobility||The cooker must be able to be moved by 1-2 people (i.e. wheels, handles, lightweight)|
|Durability||Must function for multiple years around children and withstand UV rays|
|Budget||Must stay within the means of our budget|
|Inspirational||Successfully captures kids imaginations and inspires them to seek further education in appropriate technology|
Parabolas and parabolic surfaces are always something fun to learn about. They have a unique shape that gives them properties that are pretty interesting. They have the power to focus radio, light, and even sound waves into one focal point using reflection. The unique shape of the curve gives the parabola this unique characteristic. In order to find the focal point, one must use the equation y = p * x2, where p is the constant
Parabolic Solar cookers are devices designed to capture the suns direct heat using a parabolic shaped reflective surface. They work by reflecting the suns rays into one central focal point creating temperatures exceeding 500 F used to heat, cook, and pasteurize food or water. Parabolic Solar cookers date back many centuries to civilizations all around the world. From the Greeks, to the Aztecs, to The Ancient Chinese and Romans, they all had a version. And since the sun is the only source of fuel needed to create heat for use, they are practical to create and inexpensive to operate and maintain, making them a perfect educational tool for sustainable cooking.
Description of maintenance. Probably a small table with tasks and money/time each will take.
Proposed Time Line
These are the tentative dates for the completion of each goal.
|Design Completion||18 February||26 February|
|Acquire all necessary materials||18 February||05 March|
|Construction||05 March||23 March|
|Testing||23 March||30 March|
|Demonstration||02 April||02 April|
|Follow up||02 April||14 May|
Here is the proposed sortable budget for the Jefferson Community Center Parabolic Cooker
|Quantity||Material||Source||Cost ($)||Total ($)|
|1||5' Length of Chain||Ace Hardware||1$/ft||5.00|
|1||String For Construction||Ace Hardware||5.00||5.00|
|1||Pot for cooking demonstration w/ Lid||Thrift Store||5.00||5.00|
|3||Wooden Dowels 1" x 8'||Ace Hardware||20.00||60.00|
|1||Sheet of reflective Aluminum - 5' x 8'||Local Scrapyard||~100.00||~100.00|
Directly after construction of the cooker, several tests were administered to determine the effectiveness of the parabola.
The first test was simply placing a small bundle of paper in what we assumed was the focal point to see if it would ignite. It smoked and charred for approximately 30 seconds but never ignited. Next, we put 1 pint of water in a pot which was suspended form the bamboo tripod. After approximately 20 mins, some bubble were visible but no boiling was recorded.
To better aim the dish at the sun, we employed the "pencil shadow" technique. This entails screwing a pencil into the securing nut at the center of the cooker. With the pencil sticking up perpendicular to the dish, we placed a piece of paper with a hole in the middle around the nut so a shadow from the pencil was easily visible. This allowed us to adjust the cooker until no shadow was visible, meaning it was pointed directly at the sun.
Once the panels had been thoroughly cleaned and the dish aimed directly at the sun, we ran the same two test again. A soda can sized bundle of brown paper was placed in the focal point of the cooker and within 20 seconds it was on fire. This means that the temperature at the focal point was at least 451 degrees F. Second, we placed 1 pint of water in the same pot and found that it took 10-15 minutes to boil.
Further testing will include an infrared temperature gun to accurately measure the focal point temperature. Different cooking mediums, such as skillets, pans, and dutch ovens, will also be tried to determine which cooks food/water most efficiently.
Discuss the testing results.
Discuss lessons were learned during this project and what you would do different next time.
Discuss any next steps for the project as it goes on into the future.
Introduce team and semester in the following format:
Grading criteria for the remaining sections:
- Grammar and spelling +10
- Formatting +10
- Depth, breadth and accuracy of content +70
- Project documentation's potential for impact (e.g. reproduction) +10