Explosion and fire are inherent hazards associated with fuel-fired equipment such as boilers, ovens, dryers, and furnaces. A critical time is during startup or shutdown when the equipment is in transition.
A fuel explosion occurs when an accumulated combustible mixture is ignited within a confined space, such as an oven or furnace enclosure. Fires occur when combustible products or the accumulation of combustible residue are ignited, such as inside ovens and exhaust ducts.