FIRE EXTINGUISHING TESTS OF CONCENTRATED AQUEOUS SOLUTION OF FERRUM(III) SULPHATE

Abstract

Introduction. One of the priority tasks of fire safety and, in particular, fire extinguishing is the search for new extinguishants that can have a significant fire extinguishing effect, i.e. very effectively stopping the spread of flames. Because of this, promising substances that could be used to develop a new generation of aqueous fire extinguishers are inorganic iron salts and d-metal atoms, which can show a great tendency to chemical bonding with heteroatoms of various combustible substances and with active flame particles.
Purpose. The work aims to test the fire extinguishing properties of a concentrated aqueous solution of ferrum(III) sulphate and experimentally establish the quantitative parameters of the aerosol extinguishing of a class "B" fire.
Methods. Fire-extinguishing tests of the concentrated aqueous solution of ferrum(III) sulphate in the open space, were carried out according to the developed method on a flame extinguishing system consisting of a pneumatic spray (Record 2200 ESO) with a built-in tank (0.5 L) and spray nozzle ( 1.2 mm), a compressed air cylinder equipped with a pressure reducer in the test system (minimum 6-8 atm.) and manometers with an upper limit of 1.6 MPa, as well as the circular deck ( 40 cm) with combustible liquid (diesel fuel with addition of gasoline, the A-95 brand (DSTU 3675-98)).
Results. Under the conditions of the test, the duration of extinguishing the ignition centre (class "B", area – 0.126 m2) with 40% aqueous solution of ferrum(III) sulphate is 5 s. The fire-extinguishing efficiency of an aqueous fire-extinguishing agent concerning water, taking into account the duration and feed of extinguishing a hydrocarbon flame, increases 4.9 times.
Conclusion. Experimental studies have shown that the short-term aerosol action of 40% aqueous solution ferrum(III) sulphate directly on the hydrocarbon flame causes it to be quite effectively extinguished. It was found that under the conditions of the experiment, the duration of extinguishing the flame with an aerosol of a water-extinguishing agent is 5 s, which is 4.9 times more effective than water. The minimum volume of 40% aqueous solution of ferrum(III) sulphate used to extinguish the flame is 0.2 L/m2.