EPA Solar Water Pasteurizer with Integral Heat Exchanger Project # P07401 Rochester Institute of Technology EPA Solar Water Pasteurizer with Integral Heat Exchanger Elaine Aiken, Kellen Bucher, Sulen Gonc, Alex Kinlock, Drazen Hadzialic, Nathan La Croix, Sang Lee Abstract Background People, Planet and Prosperity” principles were Integrated into a multi-disciplinary engineering design project to develop an inexpensive water cleaning technology for developing countries. Solar Water Pasteurizer with Integral Heat Exchanger makes use of solar energy that is converted to thermal energy in order to kill pathogens at elevated but not boiling temperatures. The team addressed issues such as cost, availability of materials and processes in the designated country, percentage reduction of the pathogens, sediment in water source, daily output as well as usability, durability and maintenance of the overall system. A formal design process was followed to recognize and address the needs, create design objectives, generate concepts, finalize a design, and build a prototype within the sustainability constraints. According to the World Health Organization, there are over one billion people that do not have access to clean water, and every year, over five million people die due to lack of safe and sanitary water. According to UNICEF, 50% of the children in rural areas in the 50 least developed countries do not have access to improved drinking water sources. At the 2002 World Summit for Sustainability Conference, a target was set to halve the proportion of people without access to clean water. While considerable improvements have been made to get clean water to urban areas, it is the rural areas of the developing world that fall short of providing safe water; therefore search for inexpensive water cleaning technologies are in rightfully in high demand. Customer Needs & Specifications Concept Generation & Selection Key Needs Cost Fabrication Availability of materials Output Durability Safety Usability Key Specifications Cost per unit to manufacture # of imported parts Average daily potable output Leak proof Pathogen reduction Usability for Setup Required maintenance duration Dimpled Surface Evacuated Tube G View A View A Pasteurization Testing Baffle/Baffle Temperature Difference Life-Cycle Assessment Pasteurization is a method in which heat is used to kill bacteria, pathogens, or viruses. It is a function of time and temperature The graph above summarizes the time-temperature relationship A cradle-to-grave Life Cycle analysis was done for the environmental impact of the pasteurizer. SPIHX received a rating of 3.37 eco-points Steady-state flow of pasteurizer on May 3, 2007 The pasteurizer is made up of three sheets of aluminum that is enclosed in a plywood enclosure. The three sheets are assembled together such that two channels are created for water flow. The contaminated water is fed through the inlet bucket in the feedwater system and travels to the top channel. The top aluminum sheet is painted with a selective coating which enhances solar absorptivity while retarding emissivity. Once pasteurized, the thermostat valve opens and the water flows through the bottom channel where the aluminium sheet facilitates heat exchange between the hot outgoing pasteurized water and cold, incoming contaminated water. The pasteurized water is then collected in the outlet bucket. The valve remains closed until pasteurization levels have been reached; once open, it will remain open as water will continuously pasteurize and flow making the SPIHX a faster means of obtaining potable water as opposed to a batch pasteurization process. FINAL DESIGN