December 14, 2003
Tornado in a Can
By ERYN BROWN
SourceThe awesome destructive force of tornadoes -- iconized in ''The Wizard of Oz'' and fetishized in ''Twister'' -- has been harnessed by a 65-year-old farmer who, as central casting would have it, hails from Kansas.
Frank Polifka, who farms wheat and milo, invented a contraption called the Windhexe, which creates a tornado-force wind within a steel funnel. A contained cyclone, it turns out, is very useful for pulverizing things. Polifka has reduced broccoli to powder. Same with rocks, aluminum cans, shark cartilage, coal, sewage, household garbage and the membranes that line eggshells. Now, with the help of business partners, his machine is being put to use on bigger things. Energy companies in Australia are using it to remove moisture from coal. A garbage-processing plant in Pennsylvania will go online with its Windhexe next month; the machine can turn two tons of trash into one ton of sterile powder. And in November, a North Carolina poultry processor started turning chicken parts into a high-protein powder for use in the manufacture of pet food.
Polifka, who made his first Windhexe about 15 years ago, designed his machine to push compressed air through nozzles at the top of the funnel-shaped can. Small deflection plates then force that air to flow in a counterclockwise direction, creating a miniature tornado. Using just a fraction of the energy employed by conventional crushers and dryers, the Windhexe breaks solid material down, increasing its surface area. It then exposes the degraded material to the heat cast off by its air compressors, evaporating any moisture within. David Winsness, an engineer who is working with Polifka to market the invention, envisions a day when every home will have its own Windhexe -- churning loads of household trash and sewage into handfuls of fine powder.
These mundane uses don't mean the fearsome twister has lost its mystique. One of the most delicious things about the Windhexe is that theoretically the thing shouldn't work at all. Its compressed-air streams don't have enough energy to crush much of what it pulverizes. But somehow when those air streams are molded into the shape of a tornado, they become supercharged. ''An engineer could not have invented this,'' Winsness says. ''As an engineer, you don't try anything that's theoretically impossible.'' (Polifka has a 12th-grade education.) ''I don't know what it really does,'' admits Polifka, who once tried and failed to photograph the inside of a working Windhexe using strobe lights. ''No one's been able to explain it.''