Cases in the News

Perhaps one of the best ways to learn about process safety is to study the experiences of others. We are bringing to you our narrative on some process safety incidents that have been in news.

Coal Dust Cloud Explosion in Silo – Combustible Dust

Stonehouse Process Safety commentary: Silo explosions are not uncommon. Over the years there have been many explosions in silos for combustible powders ranging from agricultural products, to various chemicals, and in this particular case, coal. Often the finer particles (dust) remain in suspension in the silo headspace, with a concentration that exceeds the minimum required to form an explosible dust cloud.

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Flammable Vapor Fire & Explosion – OSHA Investigating

Stonehouse Process Safety commentary: Highly flammable chemicals are in widespread use in many process industries.  For as long as these materials have been in use they have been the fuel for numerous fires and explosions with a devastating loss of life, injuries, and environmental and property damage.

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Dust Cloud Flash Fire at Festival – Combustible Dust

Stonehouse Process Safety commentary: Holi is an ancient Hindu religious festival which has become popular with non-Hindus in many parts of South Asia, as well as people of other communities outside Asia. In recent years the festival has spread to parts of Europe and North America as a spring celebration of love, frolic, and colors.

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Magnesium Dust

Stonehouse Process Safety commentary: There are a number of reasons why metal dust explosions are particularly hazardous. First, dust cloud explosion temperatures and pressures for most organic materials are limited to about 2,300oC and 9 barg respectively. In contrast, explosion temperatures and pressures for most metals can reach around 3,500oC and 12 barg, and some metals such as magnesium can react with the nitrogen in air, generating even higher values.

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Powdered Milk Dust Cloud Explosion – Combustible Dust

Stonehouse Process Safety commentary: Spray driers, in general, have been the source of many dust fires and explosions over the years, yet it is a surprise to many people that many materials like milk powder will give rise to an explosion hazard when dispersed in the air.

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Avoiding the Big One – Risk of Dust Explosion

Stonehouse Process Safety Commentary: We do not comment on this serious event. We do ask why such events happen with worrying regularity and why, when much is known about safe elevator and silo explosion design, we continue to witness these shocking events time and time again. In Sioux City in the ‘70s, just a few miles away from last year’s elevator explosion, there was an elevator/ silo grain explosion that struck a bunch of grain silos – that time resulting in the death of 4 men.

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The Delayed Dust Explosion

February 2020 When something serious goes wrong on powder handling plant, how long do I have to get out before a dust explosion develops? I think we all know that individual dust explosions last for a matter of seconds. Once ignition has started, a flame front grows from the ignition…

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From flash photography to factory explosions over 130 years

Stonehouse Process Safety Commentary:

MAGNESIUM powder is incredibly useful today. Everything from aircraft parts to automotive components are made from magnesium, benefiting from the metal’s light weight and high strength giving a favorable strength-to-weight ratio. But the metal must be treated with great respect and thoughts of the photographer of yesteryear is the key to why.

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Electrostatic Spark Causes Explosion

In this issue we dig into our own case files for an explosion/ flash fire caused by STATIC ELECTRICITY. As they say, all names, places and facilities have been changed to protect the innocent…. but the story contains the essentials of a real incident and are relayed here to help us all learn from past mistakes. Look out for the EARLY WARNING SIGNS!

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Grain Fire at Malt Facility

Stonehouse Process Safety commentary: The humble screw conveyor is staple equipment for moving bulk product from A to B. Use it well and wisely and you have plant that not only will move grain or powdered materials through your facility, but it can also be designed…

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Explosion in Particle Board Production; Friction/Impact ‘Sparks’

Stonehouse Commentary: Impact Sparks

At the time of writing this article, the police had reported that there had been a dust deflagration in the so-called mill building and that it was caused by a ‘spark’. Regular readers of our Safety Dispatch articles will be aware that a number of our previous stories have concerned ‘sparks’ of the electrostatic type but given this incident, we thought it may be of interest to readers to take a quick look at ignitions caused by friction or impact sparks.

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Sawdust Explosion – Dust Hazard Analysis (DHA)

Stonehouse Process Safety commentary: Most of us have tried to start a camp fire – and usually struggled. We know if we first prepare kindling, we might light that first and hope that the logs will eventually flame. What we may not realize is that if we take sawdust from that same wood and disperse it in the air, we could have a flashfire or dust explosion on our hands. Wood needs a lot of surface area to combust, and the more you have, the faster will be the combustion.

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Food Ingredients; explosibles that make you think

Last month (September 2019) in the sleepy Dutch town of Wijhe, an explosion occurred at the Arva Spice factory.

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