Animated depiction of a cyclone functioning

To most Iowans, the word "cyclone" refers to Iowa State University-the home of the Cyclones. But in air pollution control, a cyclone is a device used to remove larger size particles, about 20 microns in diameter, from the air stream. Often, more than 80 percent of particles are removed. More efficient equipment like baghouses or electrostatic precipitators can then remove the smaller particles.

Cyclones are often found at feed mills, crushers, dryers, grain elevators, and even high school industrial arts classrooms. Photos. In industrial uses, cyclones are often used as precleaners for more expensive and sophisticated control equipment such as electrostatic precipitators or baghouses.

Dirty air is forced into the cyclone where it moves in a circular motion in increasingly tighter circles. Centrifugal force causes the larger particles to move toward the outside wall. Like a large, fast moving car attempting a tight curve, the large particles cannot make the turn. They impact the wall and fall to the bottom for collection. Particles are also knocked out of the air stream when they collide with each other. Groups of cyclones hooked together are called multicyclones. Multicyclones are more efficient at removing fine particulate matter.

Cyclone benefits:

Few moving parts, very low capital and operating cost, materials can withstand acids, high heat and pressure.

Potential concerns:

Sticky materials can clog cyclones, hard or sharp edged particles can wear them out. Fails to control ultra-fine particles.