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

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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!