Heat retaining hood assemblies, air curtain destructors with heat retaining hood assemblies, and methods for using the same

An air curtain destructor comprising:

• a firebox having an inner cavity formed from a plurality of sides;
• a centrifugal blower that blows a curtain of air across a top of the inner cavity;
• a heat retaining hood assembly configured to retain heat and direct exhaust, the heat retaining hood assembly comprising:
• at least one plenum having a contoured shape and comprising an intake opening, an interior side, and an exterior side, wherein the plenum is configured to restrict heat from flowing from the interior side to the exterior side;
• and
• at least one exhaust duct fluidly connected to the plenum and comprising a release vent;
• wherein the heat retaining hood assembly includes an exhaust flowpath having a curvature defined by the contoured shape of the plenum, the exhaust flowpath extending from the intake opening of the plenum to the release vent;
• wherein the plenum substantially covers an open top of the inner cavity such that when a fuel is burned within the inner cavity, and the centrifugal blower blows the curtain of air across the top of the inner cavity, the heat retaining hood assembly retains heat within the inner cavity and a framework pivotally connects the heat retaining hood assembly to the air curtain destructor such that at least a portion of the plenum can be pivotally opened.