Identifying the regularities of n-heptane flame inhibition by inorganic compounds

Abstract

The task related to using inorganic compounds for extinguishing flames is to enable their inhibitory capacity during operation within wide limits. Therefore, the object of the current research was aqueous solutions of inorganic salts, on which the effectiveness of inhibitory properties during interaction with n-heptane flame was established. It has been proven that increasing the mass flow rate of water by 1.5 mg/s reduces the intensity of OH-radicals radiation from 70 % to 30 % and lowers the flame temperature by 90 °C. However, it was found that when potassium salts are given, the intensity of OH-radicals radiation decreases by more than 6 times, potassium chloride and sulfate reduce the intensity of OH-radicals radiation by more than 2.8 times. Among ammonium salts, salts of dihydrogen phosphate and ammonium hydrogen phosphate reduce the relative intensity of radiation of OH radicals by more than 1.3 times. Sodium salts include nitrates and sodium chloride, which reduce the relative radiation intensity of OH radicals by more than 1.6 times. This is manifested, first of all, in the enrichment of the combustible environment with fuel. When determining the flame temperature of flammable liquids, it was established that n-heptane has the most stable and highest flame temperature, which is 1768 °C. When adding inorganic compounds to the flame of n-heptane, nitrate salt, and potassium chloride, the flame temperature increased by less than 20 °C. However, ammonium salts increased the flame temperature to over 140 °C, despite the presence of water. The practical significance is that the results were taken into account during the design and development of extinguishing agents for extinguishing fires. Therefore, there are reasons to assert the possibility of regulating flame extinguishing processes by using inorganic compounds capable of inhibiting active flame radicals