Four undergraduate engineering students from the University of Nevada, Reno's American Society of Mechanical Engineers (ASME) chapter captured first place in the 2007 ASME Student Design Competition finals in Seattle, Wash.
Team members Ian Chase, Nathan LaBrosse, Karl Schulz and Scott Waters worked together to build a human-powered water still they named the "Bicycle Boiler."
"The competition was partially based around solving one of the big problems introduced by Hurricane Katrina," Waters said. "There was water everywhere, but nearly all of it was polluted and not fit to drink. So ASME decided to create a design competition with the primary goal to boil water using only human power, essentially making it safe to drink no matter what kind of pollutants were in there."
In New Orleans, the city water system was inoperative and the water that surrounded people was either brackish or filled with both biological and chemical pollutants.
According to the ASME, one of the ways of purifying some of it would have been to distill it. However, electrical power was not available, solar energy was limited or not available, and filter systems, which could have been available, might not have removed all of the pollutants present.
So the creators of the competition decided one possible solution would be to make use of a human-powered still. This could provide at least limited amounts of purified water for drinking purposes in an emergency situation. So the students were challenged to design and build a device that would heat water to boiling temperatures and then to condense the steam generated to get potable water.
The requirements included having all significant energy input come from a linkage or mechanism driven by human effort, the device had to be small enough to be easily stored or transported for emergency use and it had to be easily assembled from its stored configuration.
"We decided very last minute to enter into the competition in the first place, so we only had about two weeks to come up with our first design last spring," Waters said. "To generate the heat needed to boil water we chose to use friction instead of generating electricity. The main power plant of our design is a modified bicycle 'fluid trainer' which is basically a stationary bike roller for use indoors. It uses a spinning disc in oil to generate resistance and most of the pedaling work people do goes straight to heat. We quickly discovered it had no problem getting to 300°F in a few minutes of pedaling.
"One cool thing about this design is that if someone has an existing bicycle, the whole project would be very portable and would only weigh about 30 pounds."
After winning at the North-American Pacific District competition last April, the team made a few modifications to the device. The main change was adding a second boiling chamber connected to a vacuum hand pump.
Waters explained that when the steam comes out of the first chamber it heats the secondary chamber, and because it is on a vacuum it boils at around 130°F instead of 212°F.
"It sounds a little crazy to have to pedal this bicycle and work a hand pump at the same time, but you only have to get the vacuum going for the first couple of minutes and then it stays put," Waters said. "This new modification was worth it though, since we increased our water output by half."
Twelve schools representing ASME districts in the U.S., South America and Asia participated in the event. The hour-long, head-to-head competition began with students charging their devices with "polluted" water, which was dyed with food coloring. Then the pedaling began.
"My team and I were pretty nervous, but in the end we looked up at the score board and saw we produced about a third more water than the second place team and almost double everyone else, so we knew the hard work paid off," Waters said. "This was definitely one of those competitions that forced us to use concepts from the classroom, and we are all really proud to represent Nevada and the engineering program on an international level. We're also grateful to the Associated Students of the University of Nevada for sponsoring us in the competition."
Dr. Kwang Kim, the chair of the mechanical engineering department believes this team represents the future mechanical engineers of excellence.
"Winning this national engineering design competition confirms the quality of the mechanical engineering program at the University of Nevada, Reno."