Alternate Solutions

Alternate Solution 1 features a desalination cone followed by 9 chambers of thermal distillation, powered by an array of solar panels on the "roof". The water travels in a circular path from chamber to chamber and eventually drips into a collection basin attached to the bottom of the unit, where UV lights can sanitize it. Water is dispensed through a faucet on the side, perhaps with an attached pitcher.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Alternate Solution 2 is basically the same as AS1, except that its storage receptacle is separate from the unit itself, which allows for an indoor storage unit and outdoor desalination unit, connected by a hose. This would make it easier for families to gain access to their fresh water.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~









 Alternate Solution 3 utilized the property of parabolas to focus light at a point to speed up the solar desalination of a desalination cone. A parabola of mirrors would be constructed around an elevated desalination cone, and the rapidly evaporating water would be carried by gravity to a storage receptacle. This configuration had very little power needs but would be difficult to assemble perfectly for maximum efficiency.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~









Alternate Solution 4 also uses the sun as the direct power for the distillation of the seawater. The traditional desalination cone is placed on top of a chambered receptacle, which holds the saltwater (to be evaporated) in an inner chamber, and after it evaporates and condenses, it is allowed to run down the sides of the cone into an outer chamber, and thence through a tube into a storage unit where UV light awaits it. The water in the outer chamber is protected from further evaporation by two slanted flaps that allow water to flow past, but block almost all light. The unit would be placed outside and elevated, so that gravity could carry the freshwater down to a storage unit inside the house. The UV lights are the only things that need power.


NEXT

Brainstorming

Top: Sketch of an early AS4. Bottom: First Sketch of AS2, originally labeled AS3

Sketch of a schematic that never came to fruition - too hard to construct and maintain. Resembles AS1

First sketch of AS1 with closeup of desalination cone

Closeup of distillation chamber and attached pitcher for AS1

First sketch of AS3 with annotations

Supplementary Research: Past Solutions

In the past, cheap and small-scale desalination devices have seen much success. For instance, desalination cones, or solar stills, have long been used in wilderness survival kits or to purify brackish water for small-scale consumption.More specifically, Ryan Erickson, a fellow high school student from Los Alamos, NM, recently designed and built a desalination device with very similar specifications to our design brief.

Ryan Erickson, 18, with his desalination unit

His machine both desalinated and sterilized the water, as ours hopes to do, and it is just as compact and affordable as we would like ours to be. Therefore, these past successes show that we should be able to accomplish our goal efficiently. A single-family desalination device is well within the realm of possibility for three high-school engineers.

Sources:
 Bagley, K. (2011, September). High School Inventors 2011. Popular Science 278, #5.

0okmnhz6 (YouTube), (2007), Watercone Solar Still, solar seawater desalination.[Internet Video]. http://www.youtube.com/watch?v=c9fepEyGRx8

Research

Introduction
Since our group is striving to design a low-cost, high-efficiency home desalination unit for rural northern Chileans, it is important not only to know about engineering principles, but about the unique motivations and needs of the customer and area. The Atacama region is distinctive due to its singularly arid climate, its lenient water rights system, and the culture of its people. All three of these areas required its own branch of research from our team.

Problem Situation/Opportunity
All the engineering knowledge in the world is useless if one cannot figure out how to apply it. As such, finding the proper problem to invest your time and attention in is one of the most important building blocks of a project such as this.

A mining pipeline in Chile (NYT)

The group was first alerted to the problem in northern Chile by a New York Times article that GMG had found. The article detailed how, since the water rights system in Chile was very free-market, the mining companies were buying up all the available freshwater sources to use for their mines and plants, leaving small towns without a viable source of drinking water. A visit to the Wikipedia page for Water Resource Management in Chile confirmed this knowledge and convinced us that Chile was the area most in need of a device of this nature. 

Environment/Climate
Researching the environment in which a device will be implemented, especially if it is an outdoor device, is integral to its success. One must learn the benefits and the disadvantages of the different characteristics of the area - what can you exploit? what should you watch out for? What must you resist? Knowing the setting is key to making the unit durable and efficient enough to properly provide for these people.

An aerial view of the Atacama region (NASA)

The Atacama desert is the driest in the world. Any aerial moisture evaporates before it reaches the ground, so rainfall in the region averages less than a millimetre a year. We learned more about the peculiar weather patterns and circumstances that conspire to leave the Atacama region so arid through the National Geographic region profile and the Atacama desert Wikipedia page. Geography.about.com was also a helpful resource. Basically, research in this area convinced the group of the severity of the Atacaman drought and its chronic nature. Information here was also very helpful to our power-focused person, who noted that the almost complete lack of cloud cover made solar power an extremely viable source of energy for our unit.

User Analysis
In engineering, it is important to understand not only what your product is supposed to accomplish, but the situation in which it will be used and who will be using it. Thus, user analysis is essential to the design of any product meant to be utilized on a daily basis.

A street in San Pedro de Atacama

 This device will be primarily designed to be used by a single-family household in the rural Atacama region of Northern Chile. This area is still mainly agrarian, though mining companies have also flourished due to the area's rich mineral deposits. The families that will be using this product will be of the lower income bracket, mainly  mine workers and subsistence farmers. Thus, the controls must be simple enough that a person with very little or no scientific education can utilize and maintain it. Repairs, filter changes and especially daily use must be as simple and user-friendly as possible.

Atacaman women

Psychologically, the people of the Atacama region are proud and resourceful. Making a life on the edge of such a barren place as the Atacama desert has never been easy, so the culture of the area was founded in hardship. Because of this, a desalination device is more appealing to the population than importing fresh water, as it gives a feeling of independence and autonomy.

Summation:

___________________________________________________________________________

Sources:

Barrionuevo, A. New York TImes. (2009, March 14) Chilean Town Withers in Free Market for Water.  Retrieved September 1, 2011 from http://www.nytimes.com/2009/03/15/world/americas/15chile.html
Pukara, C. Alto Atacama Sector Suchor. (2011, March 17). Atacama Overview: Culture. Retrieved August 15, 2011 from http://www.altoatacama.com/index.php/culture

 Silva, P. Culture of Chile. Retrieved August 22, 2011 from http://www.everyculture.com/Bo-Co/Chile.html
Vesilind, P. National Geographic. Atacama Profile. Retrieved August 30, 2011 from http://ngm.nationalgeographic.com/ngm/0308/feature3/
Wikipedia. (2011, August 20) Atacama Desert. Retrieved August 22, 2011 from http://en.wikipedia.org/wiki/Atacama_Desert

Wikipedia. (2011, September 9). Culture of Chile. Retrieved September 9, 2011 from http://en.wikipedia.org/wiki/Culture_of_Chile

Testing Procedures: Team

 Introduction:
       Our final solution is expected to quickly and efficiently remove all presence of salt and bacteria from the input water, making it sufficiently potable for human consumption. It is expected to do this without compromising the volume of the water added, and it should not need inordinate maintenence.
Our specifications require that the device not only desalinate and purify the water, but that it should do so in an efficient and streamlined manner, in order to meet the goal of instilling confidence and self-autonomy in the customers. Thus, we will not only be testing the chemical parameters of the output water, but testing the volumes of the input and output, and determining productivity.
       We will be testing three main parameters - Salinity, Bacteria Content, and Efficiency - at different stages of development. GMG will test her desalination component on its own before connecting it to the other components of the project for further testing, and the other team members will do the same with their components. GMG will conduct all salinity-parameter tests, EK will conduct efficiency tests, and EH will conduct the bacteria content tests, as per their roles in the team. Aesthetics tests will be assessed via a user survey administered at the end of the construction and testing process. The survey will not only assess the effectiveness of the unit, but also the user's feelings on it regarding it's aesthetics and general mood.
The unit will be tested where it is being built - the MAST systems lab. The desalination component will be tested on its own, outside, and the other components (and the final product) will be tested inside, in alignment with where they would be expected to function in the problem situation. The unit will be constantly running, even during testing (except for efficiency testing), which will not affect the chemistry of the water.Parameters will be tested at a sea-level, moderately humid environment. The air of the intended location of usage is much drier, but atmospheric humidity should not adversely affect too much of the process, except for perhaps slowing down the rate of evaporation and therefore the process entirely. However, since it is not feasible to go to a desert to test this equipment, compensations must be made.

(Bolded entries are the jurisdiction of GMG. Underlined Italicized entries are the jurisdiction of EH. Standard entries are the jurisdiction of EK)

Type: Exploratory/Comparison
Stage: Primary
State of Solution: pre-construction
Conditions: Materials have not been gathered. This is not a physical test.
Parameter/Specification: Which method of desalination is most suited to the problem situation?
Tools and Equipment: Computer, Internet, Notepad program
Procedure: 1. Google types of desalination, make a list
                   2. Google each type of desalination, take careful notes
                   3. Compare the desalination types against each other and against the specifications of the problem situation.
                   4. Make a decision re: which type of desalination to use in the final solution.
Target: The cheapest, most low-maintenence and high-yield method of desalination

Type: Exploratory/Comparison
Stage: Primary
State of Solution: pre-construction
Conditions: Materials have not been gathered. This is not a physical test.
Parameter/Specification: Which method of water purification is most suited to the problem situation and the chosen method of desalination?
Tools and Equipment: Computer, Internet, Notepad program
Procedure: 1. Google types of water purification, make a list
                   2. Google each type of water purification, take careful notes
                   3. Compare water purification methods against each other, against the chosen desalination method, and against the specifications of the problem situation.
                   4. Make a decision re: which type of water purification to use in the final solution.
Target: The cheapest, most low-maintenence and easiest to implement type of water purification, that works in tandem with the chosen desalination method.

Type: Exploratory/Comparison

Stage: Preliminary

State of Solution: Preconstruction

Conditions: Preconstruction

Parameter/Specification: Which green energy source would be most useful and practical for the unit?

Tools and Equipment: Computer with internet capabilities

Procedure:

1. Search the internet for information about various types of green energy sources
2. Compare and contrast different types
3. Pick an energy source to use

Target: Determine which energy source would be practical for our project.

Type: Exploratory
Stage: Preliminary
State of Solution: The solution is stationary and off.
Time: Before starting to build
Tools: Calculator, materials, ruler
Tester: EK

1. Count up all the expenses i.e. the materials, the power.
2. Make sure the desalination unit us under $300.
3. Check to make sure the desalination unit is weather proof by checking all visible materials and only using those which can be exposed to high temperature, high wind speeds, and water.
4. Make sure that none of the materials or parts that are going to be constructed are fragile.
5. Test every material for leaks before using them.
6. Make sure that the desalination unit dimensions are suitable to an average Chile household.
7. Make sure dimensions are less than 2m by 2m.  

Type: Exploratory/Comparison

Stage: Secondary

State of Solution: Preconstruction

Conditions: Preconstruction

Parameter/Specification: Determine which photovoltaic cells, solar panel brand, size, and watts we should use for our project, and purchase one.

Tools and Equipment: Computer with internet capabilities
Procedure:

1. Search the internet for different types of solar panels
2. Compare and contrast different types and prices
3. Select  a solar panel to buy

Target: Choose and secure a solar panel to use for the project.

A large graduated cylinder

Type: Assessment:

Stage: Primary

State of Solution: All Materials acquired, unassembled. Black plastic should be shaped into a cone

Conditions: Water will be used, equipment should expect to get wet. This is testing how well water will condense on the plastic cone being used.
Parameter/Specification: Condensation Efficiency/Time

Tools and Equipment: Black Plastic cone, water, bucket, timer

Procedure: 1. Suspend black plastic cone over bucket filled with water

                  2. Heat water, either by putting it in the sun or over a direct heat source

                  3. Time how long it takes for water to condense on black plastic, and how long it takes to start dripping off the tip of the cone.

Target: <1 hr

Type: Comparative
Stage: Secondary
State of Solution: Stationary, off.
Time: Before starting to build.
Tools: Bucket, beaker, Tubes, Spigots, Plastics, water
Tester: EK

1. Compare materials against each other.
2. Check the tubing for holes or leaks.
3. Pour water through one tube into a bucket.
4. Pour water through a second tube into a bucket.
5. Measure to see which tube had a better retention rate.
6. Time to see which tube was faster.
7. Measure to see which tube is longer.
8. Check the ends of each tube to see which is easier to attach.
9. Do the same with the different plastics that are to construct the desalination unit.
10. Check the spigot for leaks and holes.
11. Fasten the spigot onto a sink to make sure that it works.
12. Make sure the water flows smoothly.
13. Make sure the spigot is easy to turn on and off.

Type: Assessment
Stage: Secondary
State of Solution: Stationary, unconnected from storage unit, mid-production.
Conditions: time-sensitive, water will be dealt with.
Parameter/Specification: Desalination Efficiency/Time
Tools and Equipment: bucket, timer, graduated cylinder or beaker
Procedure:  1. Measure 2 L of saltwater prior to desalination using a graduated cylinder or beaker
                   2. Place in input tank, place in sun, begin desalination. Start timer
                   3. When all water has left input tank and is either in vapor form, condensed on the cone, or liquid in the bucket, stop the timer.
Target: <2 hrs

Type: Assessment

Stage: Secondary
State of Solution: Stationary, unconnected from storage unit, mid-production.
Conditions: Water will be used in test, equipment should expect to get wet.
Parameter/Specification: Bacteria Content
Tools and Equipment: Coliert-18, bucket, test tube, pipette

Procedure: 1. Add saltwater to desalination component of solution

                  2. Place in sun to start distillation.

                  3. Place bucket beneath outflow pipe to collect condensed fresh water

A Coliert-18 Matrix

                  4. When water has reached appropriate levels (this may take a few hours), take a sample of water in a test tube

                  5. Add an appropriate amount of Coliert-18 to test tube, measure hue change

Target: No Bacteria Present, no hue change

Type: Assessment

Stage: Tertiary

State of Solution: During Construction

Conditions: Stationary, Outside, On

Parameter/Specification: Ensure that the solar panels generate enough energy to run the UV lights.

Tools and Equipment: Wattmeter

Procedure:

1.      Use a wattmeter to measure the amount of out put the solar panel generates.

2.      Compare to the number of watts need to run the UV lights

Target: Ensure that the solar panels function properly.

Type: Assessment

Stage: Tertiary

State of Solution: Stationary, unconnected from storage unit, mid-production.

Conditions: Water will be used in test, equipment should expect to get wet.
Parameter/Specification: Salinity

Tools and Equipment: Refractometer, bucket

Procedure: 1. Add saltwater to desalination component of solution

                  2. Place in sun to start distillation.

                  3. Place bucket beneath outflow pipe to collect condensed fresh water

                  4. When water has reached appropriate levels (this may take a few hours), dip refractometer into bucket, wetting the testing slide.

                  5. Hold refractometer up to a light source, and assess level of salt content.

Target: 0-500ppm

Type: Assessment
Stage: Tertiary
State of Solution: Stationary, on.
Time: After built.
Tools: Salt water, beaker, bucket, timer
Tester: EK

1. Measure out 40L of salt water.
2. Pour water into desalination unit.
3. Start Timer.
4. End Timer.
5. Measure the amount of clean water that is in the storage chamber.
6. Subtract the amount of clean water from the amount of salt water poured in to find the water retention rate.
7. Measure the amount of clean water it produces in one day.
8. Make sure it is at least 40L.

An Atago Refractometer

Type: Validation
Stage: Tertiary
State of Solution: Stationary, Fully constructed and Active
Conditions: time-sensitive, water will be dealt with.
Parameter/Specification: Device Efficiency
Tools and Equipment: Graduated cylinder
Procedure:  1. Measure a fixed volume of saltwater prior to desalination using a graduated cylinder or beaker
                   2. Place in input tank, place in sun, begin desalination.
                   3. 1 day later, measure volume of freshwater after desalination using same method, compare with original volume.
Target: 90-95% volume retained

Type: Validation
Stage: Tertiary
State of Solution: Stationary, Fully constructed and Active
Conditions: time-sensitive, water will be dealt with, equipment will get wet
Parameter/Specification: Bacteria Content
Tools and Equipment: Coliert-18, test tube, pipette
Procedure:  1. Add saltwater to input tank of desalination unit.

         2. Wait 1 day, then collect a sample of water from the storage tank with the test tube.

         3. Add appropriate amount of Coliert-18 to water, wait 18 hours, measure hue change

Target: No hue change, no bacteria present.

Type: Validation

Stage: Quaternary

State of Solution: Post-construction

Conditions: Stationary, Outside, On

Parameter/Specification: Are the electrical components working?

Tools and Equipment: Wattmeter

Procedure:

1. Check the wiring, the electricity should be transferring from the solar panel to the UV lights.
2. Check the UV light, they should be burning brightly and not flickering.
3. Check the solar panel, the photovoltaic cells should be generating energy.

Target: Guarantee that the electrical components of the unit are functioning correctly.

Type: Validation
Stage: Quaternary
State of Solution: Stationary, Fully constructed and Active
Conditions: time-sensitive, water will be dealt with, equipment will get wet
Parameter/Specification: Salinity
Tools and Equipment: Refractometer, beaker
Procedure:  1. Add saltwater to input tank of desalination unit.

         2. Wait 1 day, then collect a sample of water from the storage tank with the beaker.

         3. Dip refractometer into sample, wetting the testing surface.

         4. Hold refractometer up to light source and assess the level of salt content.

Target:0-500 ppm

Type: Validation
Stage: Quaternary
State of Solution: Stationary, off.
Time: After built
Tools: Surveys, pencils, sample group of individuals
Tester: EK

1. Check aesthetics.
2. Give out survey to various individuals.
3. Ask individuals to take survey.
4. Collect survey.
5. Review results.
6. Fix desalination unit to adhere to suggestions of the surveyed. 

_____________________________________
Sources:

Blaster's Tool and Supply Company. Graduated Cylinder 100 mL. (2011). Retrieved 02 October 2011 from http://www.blasterstool.com/graduatedcylinder100ml-2.aspx

Idexx. Coliert-18. (2011). Retrieved 02 October 2011 from http://www.idexx.com/view/xhtml/en_us/water/colilert-18.jsf

NME National Microscope Exchange. Salinity Refractometers. (2011). Retrieved 02 October 2011 from https://www.nationalmicroscope.com/salinity-refractometers-c-29_57.html

Testing Procedures: Individual

  Introduction:
       My component of our final solution is expected to quickly and efficiently remove all presence of salt from the input water, making it sufficiently potable for human consumption. My responsibility was to choose a reliable and fitting form of desalination and implement the section of the device responsible for the desalination.
My personal require only that the device desalinate the water, and that it should do so in an efficient and streamlined manner, in order to meet the goal of instilling confidence and self-autonomy in the customers. Thus, my personal tests deal mainly with the chemical parameters of the output water.
        I will test my desalination component on its own before connecting it to the other components of the project for further testing, and the other team members will do the same with their components. The unit will be tested where it is being built - the MAST systems lab. The desalination component will be tested on its own, outside, in alignment with where it would be expected to function in the problem situation. Even when it is connected to the storage unit, the main desalination component will remain outside. The unit will be constantly running, even during testing, which will not affect the chemistry of the water. Parameters will be tested at a sea-level, moderately humid environment. The air of the intended location of usage is much drier, but atmospheric humidity should not adversely affect too much of the process, except for perhaps slowing down the rate of evaporation and therefore the process entirely. However, since it is not feasible to go to a desert to test this equipment, compensations must be made.



Type: Exploratory/Comparison
Stage: Primary
State of Solution: pre-construction
Conditions: Materials have not been gathered. This is not a physical test.
Parameter/Specification: Which method of desalination is most suited to the problem situation?
Tools and Equipment: Computer, Internet, Notepad program
Procedure: 1. Google types of desalination, make a list
                   2. Google each type of desalination, take careful notes
                   3. Compare the desalination types against each other and against the specifications of the problem situation.
                   4. Make a decision re: which type of desalination to use in the final solution.
Target: The cheapest, most low-maintenence and high-yield method of desalination

Type: Assessment:

Stage: Primary

State of Solution: All Materials acquired, unassembled. clear plastic should be shaped into a cone

Conditions: Water will be used, equipment should expect to get wet. This is testing how well water will condense on the plastic cone being used.
Parameter/Specification: Condensation Efficiency/Time

Tools and Equipment: Black Plastic cone, water, bucket, timer

Procedure: 1. Suspend black plastic cone over bucket filled with water

                  2. Heat water, either by putting it in the sun or over a direct heat source

                  3. Time how long it takes for water to condense on black plastic, and how long it takes to start dripping off the tip of the cone.

Target: <1 hr

Type: Assessment
Stage: Secondary
State of Solution: Stationary, unconnected from storage unit, mid-production.
Conditions: time-sensitive, water will be dealt with.
Parameter/Specification: Desalination Efficiency/Time
Tools and Equipment: bucket, timer, graduated cylinder or beaker
Procedure:  1. Measure 2 L of saltwater prior to desalination using a graduated cylinder or beaker
                   2. Place in input tank, place in sun, begin desalination. Start timer
                   3. When all water has left input tank and is either in vapor form, condensed on the cone, or liquid in the bucket, stop the timer.
Target: <2 hrs

Type: Assessment

Stage: Tertiary

State of Solution: Stationary, unconnected from storage unit, mid-production.

Conditions: Water will be used in test, equipment should expect to get wet.
Parameter/Specification: Salinity

Tools and Equipment: Refractometer, bucket

Procedure: 1. Add saltwater to desalination component of solution

                  2. Place in sun to start distillation.

                  3. Place bucket beneath outflow pipe to collect condensed fresh water

                  4. When water has reached appropriate levels (this may take a few hours), dip refractometer into bucket, wetting the testing slide.

                  5. Hold refractometer up to a light source, and assess level of salt content.

Target: 0-500ppm

Type: Validation
Stage: Quaternary
State of Solution: Stationary, Fully constructed and Active
Conditions: time-sensitive, water will be dealt with, equipment will get wet
Parameter/Specification: Salinity
Tools and Equipment: Refractometer, beaker
Procedure:  1. Add saltwater to input tank of desalination unit.

         2. Wait 1 day, then collect a sample of water from the storage tank with the beaker.

         3. Dip refractometer into sample, wetting the testing surface.

         4. Hold refractometer up to light source and assess the level of salt content.

Target:0-500 ppm

NEXT

Testing Survey

Desalination Unit Survey

MAST Systems Engineering 2 – Assessment of Effectiveness of Home Desalination Unit

GMG, EK, EH

Did the desalination unit remove all salt and bacteria from the water?

                       

How long did it take to produce one litre of water?

                       

Were there any major problems that required maintenance during the desalination process? If so, explain

                        ___________________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________

_________________________________

On a scale of one to ten, how unobtrusive and/or attractive is the unit?  _______ 

Would you keep it in your home permanently? __________________

Circle any of the following words that describe how you would feel if this desalination unit was a part of your daily life

Burdened                     Confident                     Safe                 Hassled                        Stupid

Independent                 Unchanged                   Free                 Annoyed                      Happy

Circle any of the following words that describe this unit, in your eyes.

Efficient                        Streamlined                  Ugly                 Bulky                   Unobtrusive

Productive                    Inefficient                      Pointless           Unworkable                 Useful

Do you have any suggestions on making this project better?

___________________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________

_______________________________________

Limitations

Materials:
Should be no larger than a 1.2 metre cube
Should be no smaller than a .5 metre cube
Should use materials easily available in northern Chile (more information on materials and availability found on EK's blog)

Energy/Power:
Should be completely powered by the sun
Should not need extensive capacitor systems
Should not be contingent on a centralized power infrastructure
(information on exact power uptake available on EH's blog)

Information:
Should interact with the consumer easily and intuituvely
Should not need to be refilled more than 3 times per week
Should not need maintenance more than twice per month
Should cost between 100 and 150 USD

NEXT

Specifications

Goals: The device should be streamlined, efficient, and productive, and should instill confidence and self-autonomy in the people that the group is targeting.

Functions: The device should desalinate and purify water so that the resulting fresh water can be safely drunk and used in household activities.

Objectives: The device should rely on solar distillation to evaporate freshwater from salt. The condensed fresh water should be collected and made easily accessible to the household.

NEXT

Design Brief: Team

A street in San Pedro de Atacama (Napolitano)

An Atacaman man on the salt flats (Napolitano)

Design and build a small-scale, inexpensive household desalination device marketed primarily towards poor rural families in northern Chile, but usable in many different environments throughout the world, specifically those with low rainfall but easy access to saline water. The unit must be durable and low-maintenence, and must provide enough water for an average Chilean family (~4 people) to sustain themselves daily.

NEXT
___________________________________________________________

Napolitano, L. Wideview. San Pedro de Atacama and Salar de Atacama Tours. (2003 August 12). Retrieved September 26, 2011 from http://www.wideview.it/travel/Peru_Bolivia_2003/en_12.htm

Design Brief: Individual

A coastal Atacama town (Offexploring)

Tierra de Atacama View (TA)

Design and build the desalination component of a small-scale, inexpensive household desalination device marketed primarily towards poor rural families in northern Chile, but usable in many different environments throughout the world, specifically those with low rainfall but easy access to saline water. The unit must be durable and low-maintenence, and must provide enough water for an average Chilean family (~4 people) to sustain themselves daily. The desalination component should purify the water quickly and completely, leaving no trace of salty taste or smell.
_________________________________
 Offexploring. Arica and the Atacama Desert: The Driest Place on Earth. (2011 March 16). Retrieved September 26, 2011 from http://beta.offexploring.com/dringtours/blog/chile/arica-and-the-atacama-desert-the-driest-place-on-earth
TierraAtacama. Sustainability. Retrieved September 26, 2011 from http://www.tierraatacama.com/en-us/hotel/sustainability.htm

Background Information

Left, map of N.Chile. Right, Map of Atacama Desert

A prominent feature of northern Chile is the Atacama Desert, one of the driest environments known to man. The desert covers over 100,000 square kilometres and is the chief aspect that distinguishes northern Chile from the rest of the country. Known as the driest place on earth, the Atacama averages only one millimetre of rainfall per annum, with some weather reporting stations having no record of rain at all. This aridity is caused by a confluence of events. One factor is the Andean altitude blocking clouds from reaching the Atacaman basin (they simply gather on the opposite side of the Andean ridge - they cannot gain enough height to surmount the world's longest mountain range). This lack of clouds results in permanently clear and sunny skies for the Atacama region, which causes chronic droughts.
Another, more technical cause of this aridity is the phenomenon of  the cold Humboldt current and South Pacific high pressure zone forming an inversion layer (a region which does not adhere to the usual altitude/temperature relationship), making it difficult for clouds to condense. At other places in the world with similar altitude, clouds can be seen, but due to this colder current interacting with South Pacific air, water cannot condense at normal levels.

Main: the coast town of Inquique. Left Inset: Aerial of the Andes. Right Inset: A dried riverbed in Atacama

_______________________________________________________________________

Children at a festival celebrating San Pedro

However, though this place seems highly inhospitable to life, people have lived clustered around the edges of the desert and at small, far-flung oases since pre-Columbian times. These tiny towns have enjoyed little growth or prosperity, however - the largest, San Pedro de Atacama, has just under 5,000 residents. The people are proud and hardy, used to tough living. Most work in mining - copper, sodium nitrate, or silver, among others, but in some of the larger towns, archeological tourism is also a growing business. The reason that these towns are not prospering, however, is due to clashes over the region's most precious resource – water.


Top Left: the strength of the Atacaman people. Top Right: A typical isolated Atacaman dwelling.
Bottom: An Atacaman house near a saline lagoon.



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Main: a chlorine-polluted river by a Chilean mine. Left Inset: Trucks en route to a copper mine.
Right Inset: A typical Atacaman copper mine

 The small freshwater oases that these towns formed around are running out, due to increased demand as population slowly rises. Furthermore, the mining companies have secured the water rights to several water sources, and dam or pollute the sources, leaving the villagers with no choice but to import fresh water. Since many towns simply cannot afford the expense of trucking in potable water, the citizens simply pack up and move, leaving a ghost town behind. This is harming not only the local economy and society, but also the economy of the rest of Chile, particularly the cities. When the Atacaman people can no longer make a living in their homes, they flock to the cities, almost refugees - not of war, but of the desert and the mining companies. These migrants put a strain on all of Chile, not to mention what the phenomenon does to the pride and livelihoods of those displaced. However, if the villagers could find a way to desalinate the salt water that is abundant in this region -  from Pacific inlets, lagoons, and salt lakes -  they could maintain their way of life and perhaps even start thriving and growing. The conventional large-scale reverse osmosis and flash-distillation plants that much of southern urban Chile favors are not feasible here - they are too expensive, use too much infrastructure and result in too little payoff. However, a small-scale personal desalinating device with minimal power uptake and easily accessible materials is the perfect solution for the problem. Dozens could be distributed throughout the town, and suddenly any water could become potable, given enough time.With this in mind, our group is striving to construct a compact, efficient distillation-based home desalination device.


Main: An Atacaman ghost town. Inset: A copper mine polluting a river

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Top Left: Sleekness, hiding the working parts. Bottom Left: The iPad is the epitome of intuituve design.
Right: Ease of use demonstrated with a WaterCone

 Since the Atacaman people, our potential customers, are mostly working-class and have rudimentary educations, this device needs to project an aura of simplicity and streamlined efficiency without including too much maintenance or technicality. Moving parts should not be visible, and the entire operation should be conducted within the machine, leaving only a polished façade for outsiders to view. Owning a desalination unit should be as simple as adding water every morning and taking it out as needed. Operating the machine should be intuitive and user-friendly. Also, since the unit (at least the desalinating portion) will be kept outside, it should be unobtrusive, so it does not clash with the outside decorations of the homeowner. If the unit is inconspicuous, the customer will want to place it in full sunlight, which will increase its efficiency. Overall, the more simplistic and sleek we can make this device, the better.

Left: This sleek espresso maker hides its workings.
Right: An unobtrusive rain barrel disguised as a planter

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Left: Exploded view of SeaKettle. Right: Conceptualization of SeaKettle

There are several devices that are designed for desalination, but few are suitable for the home. As previously mentioned, many require large-scale, centralized facilities, but there are some previously imagined solutions that would serve our purpose. One is the SeaKettle life raft, which uses solar distillation to glean freshwater from brackish ocean water. However, this is too complicated to use on land, for it has many unnecessary flotation devices and frills that the Atacaman people do not need and would only find cumbersome. Another unit that has been successful on the small scale in some African countries (like Malawi) is the Watercone, which is another solar-still-type desalination device that can turn small amounts of saltwater into potable drinking water. The yield is very small though, and is mainly used to sustain individual children, not entire families. We hope to build on these technologies by making the unit more productive, efficient and self-sufficient, which will increase quality of life for these Atacaman people.



Top Left: A sketch of a Watercone. Bottom Left: Collecting the fresh water
Right: Two WaterCones in use

NEXT

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