STUDY OF THE EFFECTIVENESS OF FIRE-EXTINGUISHING ACTION OF MEANS FOR PREVENTING THE SPREAD OF FIRES IN PEATLANDS

Abstract

Purpose. In order to improve the effectiveness of preventing the spread of fires in peatlands, means based on highly porous mineral carriers, in particular expanded vermiculite immobilized with fire-extinguishing salts, were studied. Special attention was given to the analysis of the physico-chemical mechanism of their action, which includes a physical stage (release of the inhibitor from the pores of the carrier) and a chemical stage (interaction of the inhibitor with active combustion particles).

Methodology. To determine the influence of the composition of the means on the mechanism of fire suppression, a topochemical analysis of the interaction of the inhibitor with radicals was carried out, and the dependence of the completeness of its release from the pores of the carrier on the grade of expanded vermiculite and the type of fire-extinguishing salt (ammonium phosphate, diammonium phosphate) was studied under temperatures characteristic of peat combustion conditions.

Results. It was established that explanations of the mechanism of deactivation of active combustion particles through their adsorption on the surface of the inhibitor or homolytic decomposition of molecules are insufficiently substantiated. The most convincing hypothesis is the interaction of active particles with whole inhibitor molecules, resulting in the formation of a complex that delocalizes the free valence and significantly reduces the activity of radicals. It was proven that the completeness of inhibitor release hardly depends on the grade of expanded vermiculite; however, diammonium phosphate showed better results.

Scientific novelty. The understanding of the physico-chemical mechanism of action of fire-extinguishing means based on highly porous mineral carriers has been improved. The delocalization mechanism of reducing the activity of free radicals during combustion was substantiated, which provides a more precise explanation of the inhibiting effect.

Practical value. The research results confirm the effectiveness of using diammonium phosphate as a combustion inhibitor and outline promising directions for further studies, particularly the search for more suitable highly porous carriers to reduce the induction period of the agent’s action.