Reducing the intensity of thermal radiation at the sublayer extinguishing of alcohols by ecologically acceptable aerosols

Oleksandr Harasymyuk,Volodymyr Balanyuk,Anton Kravchenko

doi:10.15587/1729-4061.2021.225216

Oleksandr Harasymyuk, Volodymyr Balanyuk + Show 1 more

Open Access

https://doi.org/10.15587/1729-4061.2021.225216

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Abstract

This paper has theoretically substantiated and experimentally established the intensity of thermal radiation at burning and sublayer extinguishing of alcohols with environmentally acceptable aerosols. An installation has been improved that determines the effectiveness of sublayer extinguishing with fire-extinguishing aerosols; a procedure that has been devised for determining the intensity of thermal radiation implies equipping it with an additional heat flow meter HFM–01 at a distance of 30 and 60 mm. The task to establish the intensity of thermal radiation when burning alcohols and its impact on the process of sublayer extinguishing of alcohols with aerosols has been solved. The dependence of sublayer extinguishing efficiency on thermal radiation implies that the fire extinguishing aerosol completely shields the surface of the combustible liquid against its action. The result of this study has established that the intensity of thermal radiation at a distance of 60 and 30 mm from the surface of an alcohol flame with an area of 234 cm2 ranges from 0.8 to 4.7 kW/m2; the intensity of burning and, accordingly, radiation, maximizes on seconds 30‒40 of burning. It has been found that the intensity of thermal radiation for ethanol decreases with the addition of an aerosol with an intensity of up to 0.2 g/s, and decreases even more at the intensity of supply from 1.2 g/s. With a further increase in the intensity of aerosol supply, the radiation intensity begins to decrease, probably due to a decrease in the rate of combustion. In this case, the flame first decreases in size up to 2 times, and then, after 2‒3 seconds, it goes out. The use of fire-extinguishing aerosol for the sublayer extinguishing of alcohols ensures the effect of several factors that synergize and reduce the intensity of evaporation, burning, and, accordingly, thermal radiation

Highlights

Extinguishing liquids in tanks using foam extinguishing agents is currently the most common way to extinguish and prevent fires and explosions of alcohols and their vapor-air mixtures
It should be noted that it follows from the results reported in [3] that when extinguishing ethanol and other alcohols on a large scale, it is necessary to take into consideration the intensity of thermal radiation of their flame as one of the main factors that complicate the extinguishing and can cause ignition of the surrounding tanks and combustible materials
The results showed that the heat flow from the burning of a mixture of acetone with ethanol was about twice as large as that of gasoline over the same area, gasoline formed a much higher thermal radiation in small-scale tests

Summary

Introduction

Extinguishing liquids in tanks using foam extinguishing agents is currently the most common way to extinguish and prevent fires and explosions of alcohols and their vapor-air mixtures. Four fire trucks were involved in the elimination of the accident, which supplied foam, the extinguishing was complicated by the fact that the alcohol leaked from the tank, and the foam did not effectively cover its surface in an upright position. In this case, the intensity of the heat flow from the fire was significant and caused the ignition of combustible materials next to the fire. It is a relevant task to reduce the intensity of thermal radiation from this type of fire

Literature review and problem statement

The aim and objectives of the study

Findings

Conclusions