Theoretical And Applied Fundamental Study On Flame And Explosion Suppression Agents

This paper put forward two new terms: "critical explosion temperature" and "flame and explosion suppression agents". Through theoretical study and experiments, it was found that ZrO₂ could be used as an effective component in anti-explosion agents. The temperature T₀ is called critical explosion temperature, at which the condensed phase and its vapor come to a balanced state, and the concentration of the combustible vapor comes to LEL. An anti-explosion and fireproof agent is a substance that can be used to minimize the possibility of causing explosion and fire in a protected place during a certain period. Inflammable materials can be found almost everywhere in such places as factories, warehouses etc. If the leaked inflammable materials had been sprayed with some anti-explosion agents first and handled in time, explosions and fires might have been avoided or reduced. It is known that explosion often accompanies with fire hazards. When fire happens, some leaked inflammable materials will result in explosion, which will raise the temperature of the surrounding space as high as 2200 K. Such a high temperature will easily cause severe fire. In addition, deflagration and detonation caused by leaked inflammable materials are also reported frequently. The nature of such explosion is same as that of combustion, i.e. both of them result from oxidation-reduction reactions, and belong to chain reaction mechanism. Their difference lies in the contact manner between the oxidants and the reducers, which results in their different reaction rate. Thus, same methods can be used to prevent or reduce the occurrences of explosion and combustion.This paper began with the determination of explosion limits at abnormal temperature. Explosion limits are important hazard index. Sufficient data of explosion limits at normal temperature have been recorded; but data at abnormal temperature are few. Ambient temperature of the production sectors is usually higher than the normal temperature, so the determination of explosion limits at temperature higher than indoor level is much more important. In this paper, the LEL and the UEL of n-pentane, n-hexane. n-heptane, n-octane, n-nonane, methanol, ethanol, n-propyl alcohol, n-butyl alcohol, n-amyl alcohol, and a mixture of water and alcohol were determined in a 20L explosion container, and the temperature range is from 298 K to 483 K. It was found that with the increase in temperature, the value of LEL will decrease, and the value of UEL will increase. Through regression analysis, the rule was found that explosion limits of different systems change with the temperature.