Air curtain destructors (ACDs) are devices used to burn forest waste more efficiently thereby reducing emissions. This more efficient burning is accomplished by forcing air into the chamber where the materials are burned. ACDs are available with large burn chambers, often necessitating transportation by truck, or in smaller units that force air into a pre-existing burn area, such a ditch or trench.
Sources: Alan R. Schapiro. 2002. The Use of Air Curtain Destructors for Fuel Reduction. In: Fire Management Tech Tips. USDA Forest Service September 2002.
USDA Agricultural Air Quality Task Force. 1999. Agricultural Burning Policy. Accessed on 11 September 2013. Available at http://www.nrcs.usda.gov