Download - Voice of Engineer Presentation
Voice of Engineer Presentation
Design for Developing NationsSpring 2012
Table of Contents1. Arborloo
a. Function Treeb. Benchmarksc. Metrics and
Specificationsd. House of Qualitye. Staffing Solutionf. Customer Feedback
2. Pasteurizera. Function Treeb. Benchmarksc. Metrics and
Specificationsd. House of Qualitye. Staffing Solutionf. Customer Feedback
Arborloo Functions
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Metrics and SpecificationsEngineering Specification
Derived from Customer Need
Relative Importance Description Measure of
PerformanceEngineering Units
Ideal Value References
ES1 CN4, CN7 9Support Weight (Mitigate risk of falling in)
Force Newtons [N] 1,13895th Percentile of Male Weight: 116 kg at Peak Weight [http://www.halls.md/chart/men-weight-w.htm]
ES2CN8, CN10, CN17
3Provide privacy to the user
Height of Walls
Centimeters [cm] 174
95th Percentile of height for females [http://www.halls.md/chart/women-height-w.htm]
ES3 CN4, CN8 9Provide a safe exit for the waste
Hole in floor/base
Centimeters [cm] <46 Sarah Brownell- Arborloo
Expert
ES4CN4, CN8, CN10, CN17
3Protect from mild weather conditions (rain, sun)
Customer Satisfaction of Roof
Binary Y/N
ConstraintsConstraint
Derived from Customer Need
Relative Importance Description
1 CN1 9Comparable to current cost of the Arborloo (<$50 w/ $100 as marginal)
2 CN2, CN11 9,3 Product made from locally available materials
3 CN3, CN14, CN20 9 Easily assembled and disassembled without electric tools in <1/2
day
4 CN5, CN9, CN13 9 Easily moved between arborloo "holes"
5 CN12, CN21 3 Easily moved from manufacturing location to "permanent" home location via donkey
6 CN6 9 Survives a Hurricane (ex: easily disassembled walls and roof, semi-permanent design)
7 CN16, CN18 3 Minimize odor and inhibit flies (ex: organic matter into hole)8 CN19 1 Make structure/platform aesthetic/modern looking
9 CN15 3 The structure/base must be easily cleaned and maintained
VOC to VOENeeds and Specs ES1 ES2 ES3 ES4
CN1* CN2* CN3* CN4 9 9 3
CN5* CN6* CN7 9 CN8 3 9 3
CN9* CN10 3 3
CN11* CN12* CN13* CN14* CN15* CN16* CN17 3 3
CN18* CN19* CN20* CN21*
*Customer need is addressed in constraints
Customer Feedback• ES1: “Mitigate risk of falling might also be related to hole
size/shape, not just support weight ... keep children from falling through?”
• Constraint 2: “don't specify locally available. I want them to compare local and manufactured materials.”
• “… not sure you need CN9 if you have CN12.”
• “CN5 could specify ‘by 4 people or less’ to combine with CN13, CN19.”
• “CN21 should have higher value/weight, maybe even 9...as this is the area where the team will need to be most innovative.”
Pasteurizer Function
PAST
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SPRODUCT Enclosed Bins Rolling Bins Compost Tumblers Worm Bins
Overview Uses redworms to compost waste that results in "worm castings"
Cost Material Best for Growers with
limited space.Homeowners with a lot of space
Homeowners with limited space and willing to invest in a compost bin
Homeowners and apartment dwellers with limited space
Pros Low Maintenance Low maintenance Energy-efficient Can be located anywhere
Lid keeps rain off compost and deters animals
Easy to aerate the pile
Easy to aerate the pile
Require little maintenance
Lid keeps rain off compost and deters animals
Supplies bacteria with necessary oxygen and speeds up decomposition
Can be used year around
Lid keeps rain off compost and deters animals
Cons Slower composting Fully loaded bins are heavy and difficult to handle
Once decomposition begins you cannot put any more material in them
Temperatures are critical to worm survival (40-80 F)
Six month to two year cycle
Reference http://www.composting101.com/compost-bins.html
http://www.composting101.com/compost-bins.html
http://www.composting101.com/compost-bins.html
http://www.composting101.com/compost-bins.html
Arborloo BenchmarksPA
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PRODUCT Heap or Pile Pit Composting Green Cone Solar Composter
Overview Uses a shallow pit in the ground (18" deep by 3' wide and as long as preferred)
Uses solar heat to compost material
Cost $165 Material Recycled PlasticBest for People with adequate outdoor
space and willing to invest timePeople who want to contain and shelter the compost pile
Pros Cheap Cheap Small, Light weight
Produces high temperatures
Long Life Span
Relatively quick decomposition
Material
Faster composting
Cons Can take a long time to decompose
Requires regular maintenance
Price
Requires manual aeration Cannot contain massive amounts of organic waste at one time
Not enclosed and can attract pests
Reference http://www.composting101.com/compost-bins.html
http://www.composting101.com/compost-bins.html
http://solarcone.net/store/Green-Cone-Solar-Digester-System.html
Metrics and SpecificationsEngineering Specification
Derived from Customer Need
Relative Importance Description Measure of
PerformanceEngineering Units
Marginal Value Ideal Value Source
ES1 CN2 9
Provide heat to waste using solar energy in order to kill pathogens
Temperature, Time °F, hours
See attached table. Refer to Humanure Handbook for more details
Humanure Handbook
ES2 CN4 9
Vent combustive gases in order to prevent explosions
Amount of methane inside chamber
ppm 50,000 Less than 30,000
http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/methane/health_met.html
ES3 CN1 9
Contain pathogens, do not allow unsafe leakage of untreated wastes
Is there leakage?
Binary (Yes/No) No No
ES4 CN4 9
Temperature of the access door (or handle of the access door)
Temperature °F 120°F Less than 100 °F
http://engineering.union.edu/SeniorProjects/2004.ME/arthurk2/Background.htm
ES5 CN5 9
The product must be able to withstand an outdoor environment
Does rain water leak into the chamber
Binary (Yes/No)
Metrics and SpecificationsEngineering Specification
Derived from Customer Need
Relative Importance Description Measure of
PerformanceEngineering Units
Marginal Value Ideal Value Source
ES6 CN5 3
The product must be able to withstand an outdoor environment
Does the product withstand outdoor wind
mph 20 mph 25 mphhttp://haitipassivecooling.tumblr.com/
ES7 CN7, CN8 3
Customer must be able to easily add, stir (optional) and remove waste
Time to add, stir and remove material
minutes 15 minutes less than 5 minutes
ES8 CN10 3 Volume of product Volume Liters 1L per person per day*
http://bend.org.au/uploads/media/CompostingLoos.pdf
ES9 CN11, CN12, CN13 1
Waste must be turned to useable fertilizer**
Is fertilizer made?
Binary (Yes/No) Yes Yes
ES10 CN14 9 Minimize SmellDoes the product smell bad?
Survey 80% think its ok 90% think its ok
ES11 CN2 9
Does the entire sample of human waste contain safe pathogen levels?
Test for pathogen level
See attached table. Refer to Humanure Handbook for more details
Humanure Handbook Table 7.2
Metrics and SpecificationsTemperature (F) Time122 1 day114.8 1 week109.4 1 month
Constraints
Constraint Derived from Customer Need Relative Importance Description
1 CN3 9Keep total cost of manufacturing and shipping product less than $100
2 CN3, CN6, CN9 3 Product made from locally available materials
3 CN6, CN10 3No electric tools must be required to assemble, disassemble or repair the product
4 CN10 3 The assemble time of the product should be less than 6 hours
VOC to VOE
Needs and Specs ES1 ES2 ES3 ES4 ES5 ES6 ES7 ES8 ES9CN1 9 CN2 9 CN3* CN4 9 9 CN5 9 CN6* CN7 3 CN8 3 CN9* CN10* 3 CN11 1 CN12 1 CN13 1 CN14 1* Customer need is addressed in constraints
Customer Feedback• ES3: "contain pathogens, do not allow unsafe leakage of untreated
wastes." – “…and I don't want to limit their creativity.”
• ES7: “... Preferably, you wouldn't have to stir.”
• ES8: “the spec should be higher if 0.5 L is the volume of the human waste… will be mixed with … cover material”
• ES9: “I'm not expecting the pasteurizer to make compost … we could possibly approximate with a simpler e coli test.”
Staffing SolutionProject ME ISE EE CE ChE BioE ID Other Total BRIEF Mission StatementR12401 Arborloo(Imported Materials)
3 1 CivTech 5 The Arborloo is constructed using materials from outside of Haiti and imported into the country.
R12401 Arborloo(Domestic Materials)
2 1 CivTech 4 The Arborloo is constructed using domestic materials within Haiti.
R12401 Pasteurizer(Low Temp)
2 1 1 4 The pasteurizer functions at low temperatures (40oC - 50oC).
R12401 Pasteurizer(High Temp)
2 1 1 4 The pasteurizer functions at high temperatures (50oC - 70oC).
R12401 Composter 2 1 1 4 The composter will compost raw materials (including human waste).
Team LeaderStructural EngineerInterface EngineerThermal EngineerSanitation EngineerFacilitator
List of PRPs• Imported Materials Arborloo – Jordan• Arborloo Toilet Design With Domestic
Materials- Kylie• Low Temperature Human Waste Pasteurizer -
Kevin• High Temperature Human Waste Pasteurizer
- Avash • Human Waste Thermophilic Composter for
Developing Nations - Andrew
Questions?Thank You!