Water pasteurizer

Market Suggested Retail Price

$2,400.00

Distributors / Implementing Organizations

Seeds of Hope International Partnerships (SoHIP) in Zambia and MAPLE Microdevelopment in Uganda

Manufacturing/Building Method

The product is in the prototype phase and is not yet manufactured.

Intellectural Property Type

Trademarked

User Provision Model

Unknown

Distributions to Date Status

The product is in the prototype phase and is not yet distributed.

Design Specifications

The water pasteurizer comprises of heating coils, a heat exchanger, and regulating thermostatic valve - all housed in a 60 L pot, and is designed to work with 60 L and 100 L cookstoves but could potentially be used with other biomass heat sources. Water is gravity fed from an elevated tank (3-4.5 m) and enters into the hot-side of the heat exchanger, then it passes through a coil where it increases in temperature. Next, a thermostatic valve regulates the system by only opening if the temperature of the water is above 71 °C. Water then flows through additional piping before re-entering the heat exchanger and cooling down to room temperature as it exits the system.

Technical Support

Contact the designer

Replacement Components

Some components can be available in local hardware stores, otherwise, contact the manufacturer.

Lifecycle

Estimated 10 years^{Interview with designer}

Manufacturer Specified Performance Parameters

The product meets WHO requirements for drinking water while using up to 97% less wood per liter compared to boiling over an open fire.^{Interview with designer}

Vetted Performance Status

Laboratory testing was conducted by Oregon State University and found a 99.9999% reduction in E. coli through the pasteurization unit in all samples and an average clean water production rate of 6.7 L per minute. The steady-state production of clean water required an average of 5.5 g of dry wood equivalent per liter of water pasteurized or 106 kJ of energy per liter. When accounting for system startup, it required 9.1 g of dry wood equivalent per liter of pasteurized water produced or 175 kJ of energy per liter.

Safety

Handling firewood and feeding the stove presents a reduced burn hazard compared to a typical open cooking fire. The pasteurization unit is designed to cool the water down using a heat exchanger so that the water at the outlet does not exceed 20 °C and does not present a burn hazard.

Complementary Technical Systems

The designer specifies that off-the-shelf or purpose-built filters can be connected in-line with the pasteurizer to remove non-microbial contaminants present in a particular water source such as sediments, metals, or synthetic organic compounds.

Academic Research and References

Compliance with regulations

Meets WHO requirements for drinking water and US-EPA regulations for coliform and virus reduction.^{Interview with designer}

Other Information

Received the Impact Invention Award from the Lemelson Foundation in 2017.