Abstract
Explosions can be considered to be the most devastating events in industry. Reasons that lead to such an event are often very complex. Nonetheless, the basic phenomenon is generally simple. To understand what leads to an explosion and how this can be prevented, the underlying physical and chemical processes as well as the basic steps that lead to an explosion are clarified. Practically a system of standards and regulations ensures a framework to avoid unwanted events. This together with typical sequence of events will be given and lead to a general overview of explosion process safety.
TopIntroduction
Explosions are the worst events to be expected in process industry. These lead to damages due to a pressure rise and the accompanied heat release. Often these are followed by secondary explosions, accidental releases and uncontrolled fires. In the field of process safety explosions can be defined as rapid exothermal oxidation reactions. Based on this fundamental process the systematic to avoid explosions is built, focusing on either the fuel, the oxidant or the source of ignition. Additionally, measures to limit the consequences have to be applied wherever an explosion cannot be avoided for sure. This system is reflected in the European regulations for explosions protection, as well as in other laws worldwide. An international market of cause makes it necessary to consider different regional regulatory approaches. In fact, regulations cannot cover all possible situations, as the complex world of process industry cannot be totally be reflected. For this reason, the limits and expected consequence when crossing these are theme. Altogether, the chapter will enable the reader to understand the principle of explosion safety in process industry, how it is applied and when situation occur where special precaution is needed.
Key Terms in this Chapter
Source of Ignition: Physical or chemical process that provides the necessary energy to ignite a substance.
Explosion Region: Concentration of fuel in air that is ignitable, limited by the lower and upper flammability limit.
Deflagration: A combustion that spreads at a speed which is lower than the speed of sound in the burning medium.
Detonation: An Explosion that is faster than a Deflagration and where the spread of the chemical reaction is coupled with a shock wave.
Fuel: Any substance that can be oxidized so can be burned – a combustible substance
Safety Characteristics: Standardized values to describe the potential danger of substance; used to define measures for save handling and processing.
Ignition: The process to start a combustion in a way that it is self-sustaining.
Explosion: In general process in which a very large amount of energy is released in a very short time; in process safety usually fast combustion process that liberates energy in form of heat and pressure.