While
I gazed in disbelief, Wally explained how his incredible power wheel works
(see diagram above). A
few weeks later I again visited the Kinetics lab. By then the propane bottles
had evolved into 12 containers of steel pipe welded into a polygon. The principle
remained the same. I watched as Wally opened the valve to let in a trickle
of water from solar panels on the roof of his parking shed. The water temperature
was 155 degrees F. Almost
imperceptibly, the wheel started to turn. The speed picked up a bit and I timed
a revolution -about one rpm. Minto noted my misgivings. "Try holding onto the
shaft," he said. I grabbed the shaft firmly - it was as if I'd tried to stop
some eerie, irresistible force: no sound, no evidence of power, just pure twist.
"Picture
one 200 feet in diameter," he said. This time my mind boggled. Such a rig might
hoist the pyramids. Wally
doesn't expect industrialized nations to scramble for his wheel, and he isn't
selling anything. He's donating it as a "gift to the world" and expects it
will be used in undeveloped, energy-short areas. For
example, a practical 33-ft. diameter wheel running on a temperature difference
of as little as 3 1/2 degrees F and producing several horsepower could pump
irrigation water, grind grain, or saw wood. The materials could be scrap pipe,
and no machining or skills are needed to build it. Several low-boiling materials
might be used, but propane or R-12 may be best. Minto
estimates a slightly larger (40-ft.) wheel with 14 pairs of 1-ft. x 4 1/3-ft.
containers would provide 10,240 ft./lb. of work per container as each 269 lb.
of liquid responds to gravity through a 20ft. lever arm. At only one rpm this
is 8.69 hp; not spectacular, but low cost and capable of running steadily for
generations. The slow rotational speed can be stepped up to whatever is needed,
just as with the old-time waterwheels. No
fuel would be needed in many cases. The temperature difference required between
the liquid on the bottom and the top occurs naturally in many situations: water
and air, light and shade, etc. Minto
has outlined construction details in a two-sheet paper entitled "The Minto
Wheel." There are no restrictions on building or experimenting with the wheel. |