Heat-powered fan to make stoves cleaner

WASHINGTON - A Pennsylvania State University student is helping design a better cook stove for people in developing countries.

Paul Montgomery will present a simple heat-powered fan that could help to make these stoves more efficient and combat the serious health problems associated with cooking in unventilated spaces.

Some moderate-sized devices generate combined heat and power, or CHP.

The smallest of these highly-efficient machines can make, for example, 2 kilowatts of heat and 1 kilowatt of electricity. But even this is too much for a person in a rural area to use and too expensive, so Montgomery is trying to make a simple appliance that is 100 times smaller still.

His device, still at the experimental stage, captures some of the stove’s waste heat and converts the heat into sound waves in a simple thermo-acoustic engine. Then the acoustic energy is converted into a tiny bit of electricity in an electro-acoustic transducer. The electricity in turn can partly charge a battery (delivering well-needed lighting after dark) and operate a fan directed at the combustion of the stove’s biofuel, making the whole process more energy efficient.

The more efficient combustion, the less biomass must be burned to cook and the less smoke produced.

“Although a thermo-acoustic cogeneration cook stove would produce only on the order of ten watts of electrical power,” he says, “there are probably two billion biomass-fueled cook stoves in use worldwide that might benefit from nano-CHP technology.”

The target price for the device that attaches to the stove is 25 dollars, says Montgomery.

The report will be presented in the meeting of the 2nd Pan-American/Iberian Meeting on Acoustics in Cancun, Mexico. (ANI)