Alpha Prototype Presentation Nov 4, 2008

Today’s Presentation: System Schematic Review Materials Analysis Materials Processing Tube Fabrication Joints and Filter Designs Tank Specifications Alpha Prototype Cost Analysis Project Concerns/Plans for Beta Prototype

Schematic of Drip Pipe Irrigation System 1 m (not to scale) 6 m 20 cm spacing between plants Large Particle Filter Water Tank

Materials Analysis HDPE  cheap & environmentally friendly. HDPE bags  widely available in Ethiopia. HDPE bags  Too light to be fed into grinding machine.

Material Processing Two ways of making pellets out of plastic bags: 1. Heat (320 F) + Pressure (1000 Pounds) 20 bags to get thick solid sheets; Cut the sheet into smaller rectangular pieces to fed into grinding machine Carver Press

2. Roll 6 plastic bags in a cylindrical shape and feed. Shredded Plastic bags Grinding Machine

Tube Fabrication 75% LDPE pellets + 25% HDPE shredded bags by weight. Used Blown Film Processor Blown Film Processor

Blown Film Processing

 Fabrication Steps 1. Pour in the pellets into hopper 2. Blown film coming out from the circular die

Fabrication Steps (Continued)  3. The HDPE tube growing in length 4. Pulling at a constant rate to make long tubes

 Initial SolidWorks Models: Elbow Joint Y Joint  Prototype made with simpler joint designs made of HDPE Initial Joints Designs

Alpha Prototype Joint Design Solid HDPE tubes with holes drilled in them. Tube is affixed onto opening: – Superglue (bad seal) – Soldering iron (decent watertight seal) – Shrink wrap? (possible future consideration)

Filter Design Alpha Prototype does not include the designed filter

Tank Specifications Original Plan: A 110 Liter Tank (3 water refills/day) – Sorghum Plants in 6m X 6m Plot – 230 Sorghum requires a maximum of 3-4 Inch of water/10 days (during its highest growth phase) – At the flow rate of 51 L/hour the plants needs to be irrigated for 6.25 hours per day The plot will require 320 L/day of water Prototype Tank: 2.5 Liter water jug (Smaller scale)

Alpha Prototype Tubes are inserted into the T and elbow joints. Superglue, soldering iron is used in the attachment of some tubes to ensure stability. Smaller scale Drip Irrigation System 2.5 Liter Water Tank

Cost Analysis Total Cost = $ 2.69 per system Materials Cost – $0.85 for injection molded water tap – $0.80 for 48 feet of tubing (including 5% rejection rate) – $0.70 for joints, elbows Utilities Cost – $0.03 per system based on current costs of electricity Other Costs (Rent, Machinery, Delivery) – Not included – Rent = $14 per system – Sunk $77 per system after 1 years $15 per system after 5 years Problems include high costs of machinery Labor Costs – would have to be $0 to make this reasonable without much funding

Project Concerns Leaking of water from the joints Some tube/ joints attachments less stable (use of superglue) Not 100% recyclable material Tubes not straight (tend to curve) Tube diameter not even throughout

Plans for Beta Prototype Better T and elbow joints Better/more stable attachments of tubes to the joints Tube of uniform diameter Greater number of tubes (a larger drip irrigation system) Fabrication of filter for grey water

Any Questions?

Initial Output Valve Design  3-D Printing currently presenting problems with assessing design.

2 nd Generation Output Valve Design

Filter Material 36in X 100 ft Charcoal Aluminum Screen for $82.00 a roll Required filter area would be 32 in 2 Allows for 1,375 filters at 6 cents a piece.

Pressure Flow Calculations efunda.com

3 rd Generation Output Valve

3D Print of 2 nd Generation Design