What is explosion and Which areas are explosive ?
WHAT IS AN EXPLOSION?
An explosion is a rapid expansion of gas that occurs as a result of a sudden combustion process. This expansion causes a sudden increase in pressure, creating a blast wave. Explosions are often characterized by high temperature, pressure and noise.
For explosions to occur, three factors called the explosion triad must come together: oxygen, fuel and an ignition source. These three factors initiate the combustion reaction necessary for explosions to occur.
Explosions can occur in different environments, for example in containers or facilities filled with explosive gases, dusts, liquids and other materials. Explosions can often cause serious injuries, deaths, major damage and fires.
Generally, explosions occur in closed places. When there is a flammable gas or flammable liquid vapor in a tank in a closed place or in a building, it is ignited by a very small spark. The flame spreads rapidly within the closed volume, starting from the ignition point. The temperature of the gas inside increases and the gas expands. The expanding gas moves forward in the form of pressure waves, compressing the gas in front of the flame, and the gas gets hotter as a result of compression. When the flame reaches this trapped section, it continues to burn at great speed. Since the combustion area is partially or completely closed, an explosion occurs when the combustion reaches its highest speed.
Dust and solid particles in certain proportions with air (oxygen) are explosive. If there is an ignition source, these particles begin to burn explosively and can turn into serial explosions by igniting the dust and air mixtures in the vicinity.
For a powder to explode, it must be flammable, but not every flammable powder explodes. As in a flash within an explosion, there are certain concentration limits, called explosion ranges. There will be no explosion at concentrations below and above these ranges.
As can be understood from the definitions, the combustion and explosion properties of substances depend on their ignition points, that is, their flash points.
Flash points are important because it is the vapor, not the liquid itself, that creates the fire hazard. As the flash point decreases, the fire hazard increases. Liquids with flash points lower than atmospheric temperature create large amounts of vapor under the influence of heat.
WHAT IS AN EXPLOSIVE ENVIRONMENT?
Places where explosive, flammable and flammable gas, dust or vapor mix with air and become explosive are called explosive atmospheres. Three elements must come together for an explosive atmosphere to occur and create danger.
A; Explosive, flammable and flammable gas, vapor or dust
B: Air (Oxygen)
C: Energy, a spark or power source that will ignite the explosion.
If one of these three elements can be disabled, there is no danger of explosion.