Uncontrolled fire growth
On June 21, 2019 a wind driven fire severely damaged several units in a three-story garden style apartment building. An unsupervised saucepan of oil heating on a stove top allowed the oils to reach autoignition and water supply issues allowed for several cycles of enthalpy to occur to the point of full growth fire. It is the uncontrolled chemical reaction of the saucepan that heated other objects near the stove allowing for more chemical reactions to occur prior to positive water supply that allowed this fire to grow as large as it did.
Enthalpy
In this scenario an otherwise normal exothermic operation of heating cooking oil was unsupervised, and the oil was heated to the point of combustion. Negative enthalpy from the stove released energy to the saucepan and an exothermic reaction of the oil occurred. The exothermic reaction heated other materials creation more negative enthalpy creation more energy release. This all occurred in a closed apartment allowing for the pressure of the reactions to build. The release of energy under the building pressure is known as negative enthalpy.
Points to Ponder
The fire occurred in the kitchen of a two-bedroom apartment with an overall dimension of 32’4”x20’6”x8’. The bulk of the fire was in the kitchen but the energy that was released overtook the fire room. The over pressure of the fire room pushed heat and fire out of the kitchen and into other rooms of the apartment. The crews entered the fire apartment allowing the fire to breath, when the handline was opened to extinguish the fire there was no water allowing the fire to grow rapidly. The fire doubled in size and the added heat burned somw or the firefighters.
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