Common Types of Industrial Explosions

This article will discuss the most common types of industrial explosions that workers in various industries may be exposed to during their employment.

What Causes an Explosion?

An explosion is a rapid expansion of gases.  Many industrial explosions occur when gases are exposed to a source of heat, such as fire, sparks, even static electricity, or an increase in pressure. Industrial explosions can also be caused by chemical reactions.  For instance, when two or more incompatible substances are combined, they may explode.  See Reducing Explosion Hazards.

What Types of Industrial Explosion Exist?

While this list is not exhaustive, these are the most common types of industrial explosions that workers may be exposed to in various industries, including oil and gas, offshore work, drilling, construction, maritime, chemical, and others.

Chemical Explosions

In chemical explosions, the generation of high-pressure gas is the result of exothermic reactions wherein the fundamental chemical nature of the fuel is changed. Chemical reactions of the type involved in an explosion usually propagate in a reaction front away from the point of initiation.

Chemical explosions can involve solid combustibles or explosive mixtures of fuel and oxidizers, but more common to the fire investigator will be the propagating reactions involving gases, vapors, or dusts mixed with air. Such combustion reactions are called propagation reactions because they occur progressively through the reactant (fuel), with a definable flame front separating the reacted and unreacted fuel.

Combustion Explosions

The most common of chemical explosions are those caused by the burning of combustible hydrocarbon fuels. These are combustion explosions and are characterized by the presence of a fuel with air as an oxidizer. A combustion explosion may also involve dusts. In combustion explosions, the elevated pressures are created by the rapid burning of the fuel and rapid production of large volumes of combustion by-products and heated gases. Because these events are likely to be encountered by the fire investigator, combustion explosions are considered here as a separate explosion type.

Combustion reactions are classified as either deflagrations or detonations, depending on the velocity of the flame front propagation through the fuel. Deflagrations are combustion reactions in which the velocity of the reaction is less than the speed of sound in the unreacted fuel medium. Detonations are combustion reactions in which the velocity of the reaction is faster than the speed of sound in the unreacted fuel medium.

Several subtypes of combustion explosions can be classified according to the types of fuels involved. The most common of these fuels are as follows:

1. Flammable gases
2. Vapors of ignitable (flammable and combustible) liquids
3. Combustible dusts
4. Smoke and flammable products of incomplete combustion (backdraft explosions)

Electrical Explosions

High-energy electrical arcs may generate sufficient heat to cause an explosion. The rapid heating of the surrounding gases results in a mechanical explosion that may or may not cause a fire. The clap of thunder accompanying a lightning bolt is an example of an electrical explosion effect. Electrical explosions require special expertise to investigate and are not covered in this document.

See NFPA Guide for Fire and Explosion Investigations, 2004 Ed.

How Can Industrial Explosions be Prevented?

To prevent an industrial explosion, you need to eliminate one or more of the components of the ignition triangle – heat, fuel, and oxygen. There are 3 ways you can do this:

• Explosion Containment
• Segregation of the hot surfaces or electrical parts from the explosive materials
• Limiting both the electrical and thermal energy and keeping them at safe levels.

A group of experts for the Coal Mine Methane, Sustainable Energy Division (UNECE) identified a few ways explosions could be prevented.  Their suggestions included:

1. Minimize flammable gas accumulations
2. Minimize potential sources of ignition
3. Maintain separation between gas accumulations and ignition risks where practical
4. In designing gas control measures, apply factors of safety large enough to accommodate observed variations – mandatory limits may not be sufficient.

See Best practice explosion prevention.

What do I do if I Was Burned in an Industrial Explosion Incident?

If you were involved in a serious industrial explosion incident, you must work with an experienced Houston industrial accident lawyer for a free, confidential consultation.  At Morrow & Sheppard LLP, we have handled more than a billion dollars on behalf of our clients throughout the United States with a focus in Texas, Louisiana, and New Mexico.