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Background

The word "Synergy" comes from the Greek words for “to work together”. This project combines the existing parabolic shape and comfortable sitting cushion of the Papasan chair with the natural-source energy utilization of the solar cooker. My hope was that, in the spirit of synergy, the whole would be greater than the sum of the parts and that people may find the idea of owning a solar cooker more practical if they can also sit and read a book in it when its not in use. Compared to the traditional mono-functional Parabolic Solar Cooker, this project serves as a chair when not in use, which saves space and is less of a fire hazard than the traditional Parabolic Solar Cooker. The opportunity to work with Bart Orlando means that this project can benefit from innovative design that comes from years of experience. It is built mostly from salvaged materials as to not contribute to consumption.

Literature Review

http://solarcooking.wikia.com/wiki/Compendium_of_solar_cooker_designs

http://solarcooking.org/ http://www.fsec.ucf.edu/en/research/solarthermal/solar_cooker/documents/reflectivematerialsreport.pdf

Criteria

These are the criteria that the project was designed to meet.

Time – Must be able to be designed and constructed within the timeframe of one college semester, or about 4 months of part time labor.

Budget – No set budget, however the more materials that can be salvaged or easily acquired by most people, the better.

Durability – The project must be able to withstand periodic exposure to the elements, especially sun, over the course or years. Also, sitting in the chair must not damage the reflectors.

Portability - The device should be lightweight so that one person could move it without toil, and compact enough to be towed via bike trailer. Rattan, the fiber that many Papasan chairs are made from, is reasonably light weight- making reflector material the key issue in terms of weight.

Design - Should incorporate new improvements or previously not thought of innovations to the solar cooker plan. Should be stable in mild wind.

Synergy/Integration - Should be a multi functional device, capable of easily purifying water as well as cooking food, igniting paper or grass when needed, and still be able to fit easily into an everyday household setting.

Level of embedded energy - Materials should be found or salvaged so that it can be shown that this can be built without industrial equipment.

Ease of use - If multiple parts are to be used, then they should be safe, employ intuitive design, and not require the use of tools for operation.

Design

background

A solar cooker is used to concentrate sunlight onto a pot or dish for efficient, fuel-free cooking. There are several shapes a solar cooker can take on, from box-like to parabolic, spherical, funnels and plane mirrors. Each form has different pros and cons in terms of construction, durability, materials, performance, etc. In math, a parabola is a conic section with the graph (y=x²) on a Cartesian plane. If that 2-D image were to be "spun" around the origin in the 3rd dimension, the resulting shape would be a paraboloid, the shape used by this cooker. Both parabolas and paraboloids have the effect of concentrating energy waves to a point known as the focus. There are numerous examples of parabolas in the natural world. [1] Parabolic cookers seem to be heavier, more expensive and require constant tracking in relation to the sun, as compared to the other types of solar cookers. However, they have the advantage of being able to reach higher temperatures due to the precise focus created.

          =construction=

The parabola frame can be constructed from almost anything; it can be cast from a mold, be fabricated, or utilize a pre-existing paraboloid (as in this case). The frame can also be the reflective surface itself, in the case of sheet metal parabolas. A used Papasan Chair provides a stable, sturdy backbone without having to purchase new materials. This method is not available in all areas of the world, it is possible that old satellite dishes to provide cookers for a significant part of the population. The reflective surface itself can be Mylar, glass, or steel, aluminum, each varying in weight, price and availability used. PCSC - pyrex.jpg Table for reflector materials

[Image:PCSC - pyrex.jpg| A homemade insulated cooking vessel from Solarcooking.Wikia.com]

Food holding device - could be a cross bar, or suspension. suspension is much easier to integrate into a device that also functions as a chair. The suspension mechanism is a breeze to manufacture, all that is needed is bamboo poles, and a discarded inner tube. Poles should be at least 1" thick to ensure stability and longevity.

Suspension

3 possiblities

  • hot pot by Gaiam. unfortuntely, this costs $99 as the hotpot cannot be purchased from the company without also purchasing a small solar cooker. This exemplifies a good solar
  • gallon sized tin can + tempura paint- good for testing, though it may possibly off-gas small amounts of toxic chemicals. avoid this by filling the tin can with water, placing your food in a small or medium sized mason jar (with lid) inside of the tin can, and then cover the tin can with foil. This will use the double-boiler effect and not toxify your food.

3' feet chain mason jar tinfoil or cover for tin can

  • bike rim

bike rim with hooks at 120 degree angles. This is measured by simply measuring a length of string to fit the circumference of the rim and then folding the string into three equal lengths. These lengths now measure to one third of the circumference. Re-fit the string to the rim, measuring off

Implementation

Using hemp twine to tie the mirrors to the frame Checking on the water we are attempting to boil

The frame of the chair pre-mirror

Always over-build

Tied in back

Bike Rim Suspension for Frying Pan - Picture

Ideally-

The HotPot cooking vessel consists of a dark pot suspended inside a clear pot with a lid

Safety

  • As with any type of concentrated energy this has the potential to be dangerous and must be respected. Solar cookers can easily reach temperatures above 450 degrees Fahrenheit. Care must be taken around small children and animals, especially when hot food or liquid is suspended from a tripod.
  • Solar Cookers have the potential to start fires if left unattended in the sun. This is easily avoidable with this project, just put the cushion on when the Cooker is not in use.
  • Be SURE to use SUNGLASSES with UV protection when cooking/testing/adjusting your cooker! Concentrated sunlight is even more damaging to the eyes than the regular kind... And if you are wearing cheap sunglasses that only protect against visible light, you will be more comfortable than usual when staring at concentrated UltraViolet radiation that you can't see. This radiation is even more damaging to the eyes than visible light. UV protection!!

Cost

Papasan Chair - Donated

4 X 8 Anodized Aluminum Sheet - Donated*

Ball of Hemp Twine - $3.50

Pliers - borrowed

3 Bamboo poles sized 8' by 1 - mad river garden supply - $3

9' Length of chain - ace hardware - $9.00

1" long 5/16th bolt/nut - donated

1 bicycle inner tube with puncture - donated

1 small container Citra-Solv natural de-greaser - $3

1 gallon size tin can




  • Notes on reflector

From working with Bart Orlando, I had the opportunity to

Discussion

The Bamboo + bike tube = awesome stand

chair- perfect parabola? not quite. close enough to cook with. though focus is a little wide.

External Links

http://solarcooking.wikia.com/wiki/Compendium_of_solar_cooker_designs An Excellent Overv [[Image:Example.jpg]]

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