Wind Control

Preventing the wind from entraining dust particles is accomplished by keeping the wind from blowing over materials. This prevention involves confinement or wind control. Tarps that cover piles are a wind control procedure for storage piles, truck, railcars, and other sources (see Figure 5.25.1).

A variation of the source enclosure method to control fugitive dust emissions involves applying wind fences (also referred to as windscreens). Porous wind fences significantly reduce emissions from active storage piles and exposed ground areas. The principle of a windscreen is to provide a sheltered region behind the fenceline where the mechanical turbulence generated by ambient winds is significantly reduced. The downwind extent of the protected region is many times the physical height of the fence. This sheltered region reduces the wind erosion potential of the exposed surface in addition to allowing gravitational settling of larger particles already airborne. Figure 5.25.2 is a diagram of a portable windscreen used at a coal-fired power plant.

For unpaved routes and ditches, special fabrics placed over exposed surfaces prevent dust from becoming air-

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