For the average person, entering a flour or a sawmill and seeing the swirling dust is unlikely to evoke a great answer, but those who are very likely to move for the closest exit to this heartbreaking spectacle. For as harmless as a good cloud of flour, sawdust or even coffee creamer, each of them has the potential of a massive conflagation and even an overwhelming detonation.
As for the “why”, the answer can be found, for example, the principle of work behind an internal combustion engine. While a puddle of essence is definitely flammable, the only thing that really burns is the gaseous form evaporated above the liquid, Ergo, it is a relatively slow process; In order to combust the fuel, it must be mixed in the right air ratio. If this mixture is then exposed to a spark, the fuel will burn almost instantly, causing detonation due to the sudden release of energy.
Likewise, flour, sawdust and many other substances in the form of powder gradually burn if a certain transition interface is maintained. A bucket of sawdust burns slowly, but if you create a zone of sawdust, it may well explode the room.
This raises questions about how to recognize this danger and what to do on this subject.
Welcome to the chemical security committee
In an industrial context, people will generally recognize that petroleum refineries and chemical factories are dangerous and can sometimes explode in a rather violent manner. More surprising is that something as harmless as a sugar refinery and a packaging plant can go from a slight pinch of sugar dust to a violent and fatal explosion in a second. However, this was what happened in 2008 at Imperial sugar refinery of Georgiawho killed fourteen and injured thirty-six. During this disaster, a primary and secondary explosion has torn the building, destroying it completely.
Georgia Imperial Sugar Refinery Aftermath in 2008. (Credit: USCSB))As described in the US Chemical Safety Board (USCSB) report with support Video Summary (integrated below), the largest cause was the lack of ventilation and cleaning which allowed an accumulation of sugar dust, with a source of ignition, probably an overheated bearing, triggering the primary explosion. This explosion then found subsequent fuel to light elsewhere in the building, triggering a chain reaction.
https://www.youtube.com/watch?v=JG7MLSG-YWS
What is striking is how simple and direct the construction is to disaster and the means of preventing it. Even without knowing exactly airline For the fuel in question, there are only two points on the scale where you have a mixture that not explode violently in the presence of a source of ignition.
These are either a strongly saturated solution – too much fuel, not enough air – or vice versa. Essentially, if the dust collection systems of the imperial sugar plant had been up to par and extended to all the relevant areas, the possibility of an ignition event would probably have been reduced to zero.
Things like to burn
Carbohydrates are not far from hydrocarbonswho understands our old petty friend, as well as methane (ch4), butane (c4H10), etc., which are all deliciously combustible. All that carbohydrates also have carbon and hydrogen atoms are many oxygen atoms, which is an interesting addition in the context that they are potential fuel sources. By the way, also illustrates the importance of carbon for life on this planet because it forms the literal dorsal spine of its molecules.
Although we can conclude that only something that is carbohydrates or hydrocarbons is very flammable, there is a completely different world that can burn. Example to the point: metals.
Lit metals
On December 9, 2010, workers were occupied at the New Cumberland Al Solutions Titane factory in Virginia-Western, dealing with titanium powder. In this installation, the scrap and zirconium titanium were strawberry and mixed in a powder that was pressed in the discs. By the reportA malfunction inside a mixer created a heat source that ignited the metal powder, killing three employees and injuring an entrepreneur. It turns out that no method of controlling dust has been installed in the factory, allowing an accumulation of uncontrolled dust.
https://www.youtube.com/watch?v=ADK5DOMK3-K
As indicated in the USCSB report, titanium and zirconium will easily ignite in particulate form, with zirconium capable of self-intiguating in the air at room temperature. This is why the milling stage in Al Solutions took place immersed in the water. After ignition, titanium and zirconium require a class D fire extinguisher, but it is generally recommended to let large fires of metal turn off by themselves. The use of water on larger titanium fires can produce hydrogen, leading to even worse explosions.
The phenomenon of metal fires is probably better known to thermite. It is a mixture of a metal powder and a metal oxide. After igniting an initial heat source, the redox process becomes autonomous, providing fuel, oxygen and heat. Although iron oxide (III) and aluminum are generally used, many more metals and metal oxides can be combined, including copper oxide for very rapid burn.
While thermite is intentionally preserved as a powder, and often in a sort of container to create a land phase which is supported, it should not be difficult to imagine what is happening if the metal is ground in fine powder, distributed in the form of a cloud of fine dust in a confined room and exposed to a source of ignition. At this stage, the differences between carbohydrates, hydrocarbons and metals become mainly academic to all the survivors of the resulting inferno.
Prevent dust explosions
As it should be quite obvious at this stage, there is no real way to fight an explosion of dust, only to prevent it. Good ventilation, preventing dust from accumulating and having an active dust extraction in place as much as possible is almost the minimal precautions that should be taken. Comlacement as it happened at the Imperial Sugar factory simply invites disaster: if you can see the accumulation of dust on surfaces and dust in the air, you are already at least at Defcon 2.
A demonstration of the ease of creating a solid explosion of dust came from mythbusters in 2008 when they tested the “ sawdust ” ‘ myth. This involved blowing the sawdust in a cloud and turning it on with a rocket, creating a massive fireball. After almost making their facial hair sing with this roaring success, they then tried the same with non -dairy teaspoonWhich created an even more massive fireball.
Fortunately, the Mythbusters Build team was supervised by adults on the range of bombs for these experiences, as it shows how incredibly dangerous explosions can be. Even outdoors on a range of safe bombs, regardless of a closed space, as hundreds have discovered it over the decades in the United States only. Just look at the USCSB Dust explosions statistics To learn how to respect the dangers a little more.
