Welcome to the fifth installment in our exclusive series exploring the advantages and benefits of intrinsic safety technology in industrial settings. We’ve already explored how intrinsic safety works and why educating your teams about using intrinsically safe systems and devices is vital. This time, we’re looking at the tragic industrial explosions that can occur when organizations fail to have the right safety protocols in place — and how to avoid disasters like these.
Whether your industrial facility deals with food manufacturing and processing or major utilities like natural gas, there are always risks of fire and explosion. Dealing with incidents after they happen doesn’t avoid injury, damage to assets, or even loss of life. ICA explores two real-life examples of industrial explosions and the intrinsic safety benefits that could have prevented them.
Potential Fire and Explosion Risks
Every industrial facility carries the risk of fire and, potentially, explosion. The combination of electrical systems, including wiring and mobile devices with gases, vapors, and even flammable byproducts such as lint from industrial dryers, can create fires that can quickly become explosions – particularly in busy, internal spaces.
Understanding the hazardous areas in your facility is the first step to preventing disaster, but ultimately removing the risk of spark and ignition is the key to halting fires before they start. Intrinsic safety works by reducing the power levels and heat within a system, so there’s a massively reduced risk of igniting any nearby fuel sources. However, not every facility has intrinsically safe systems, which has led to some horrific industrial explosions in the past.
The Westwego Continental Explosion
Back in the 1970s, one of the worst of these explosions occurred in Westwego, New Orleans, LA. Workers at the Continental Grain Plant were either clocking in to start work or turning up to pick up their Christmas turkeys. It was December 22, 1977, and just after 9 am, locals reported a tremendous fireball shooting high into the sky and a spreading mushroom cloud of smoke and grain.
The elevators at the grain company had exploded, most likely due to grain dust — something we now know is highly explosive. Only 11 workers survived; it took weeks to unearth the 36 dead from the ruined elevators and silos. Similar explosions had occurred in recent weeks in Illinois, Mississippi, and Texas, suggesting that the national strikes that had caused backlogs of grain could have been a factor. The excess material on conveyors and elevators increased the amount of dust suspended in the air. A spark caused by a mechanical problem would be all that was required to set this dust alight, upon which it would ignite and almost immediately explode.
The Kleen Energy Power Plant Explosion
Much more recently, a devastating explosion at a power plant in Connecticut killed six workers and left at least 50 injured. The Kleen Energy Power Plant in Middletown, CT, was still under construction, and workers were attempting a “gas blow.” This is a process whereby high-pressure natural gas is forced through pipes to remove debris. Unsurprisingly, this type of gas purging causes both the gas and the debris to be released into the surrounding atmosphere. This is entirely legal, and areas where gas is purged should, ideally, be free of any ignition sources.
Unfortunately, in this instance, the team had no safety meeting about the gas blowouts and had no official procedure to follow. The gas was vented into an outdoor area surrounded by structures and scaffolding, which may have prevented the gas from dispersing as quickly as expected. The concentration of natural gas found an ignition source. While the specifics are unknown, this was likely a spark from static electricity accumulation caused by the gas flow or from the many electrical panels and devices in the area where the gas was vented. An intrinsically safe approach to the electrical equipment in the hazardous area could have prevented a disaster of this nature by removing the risk of spark and, therefore, ignition.
480,000 cubic feet of natural gas collected and exploded, most likely because of a stray spark, causing six people to lose their lives. Understanding why incidents like this happen means tragedy can be averted in the future.
How Intrinsic Safety Prevents Disaster
In both these incidents, it’s clear that disaster could have been averted by removing one point of the ignition triangle. As a reminder, all fires and, therefore, all explosions require a point of ignition, fuel, and oxygen. It’s extremely difficult to remove oxygen. Removing fuel is almost always impossible, particularly in environments with flammable chemicals, gases, vapors, or dust. Even purging or altering the atmosphere in hazardous areas creates new hazards, such as the risk of asphyxiation.
Therefore, the most sensible and practical course of action is to remove the source of ignition. Intrinsic safety reduces the level of electrical power in a system and ensures temperatures are always at safe levels. No sparks plus reduced heat equals no source of ignition. That’s the only definitive way to prevent industrial explosions before they occur.
For more information about developing and implementing intrinsic safety measures in your industrial enterprise, contact a member of the team at ICA Engineering.