Why you shouldn't have a naked flame in a powder shoot. Graphic example of what could go wrong!
Meistre said, 1500898948
Evaair said
what type of powders are flammable
There isn't a definite list because it's an issue with most powders when the air-powder ratio his a certain range. The range differs though dependant on the material but some of the common ones include icing sugar, corn starch, concrete and flour.
Meistre said, 1500899050
Jabberwocky said
Years ago when I worked in the paper industry, I was blown off my feet when a static cable come adrift from a tanker as it was filling a silo with corn flour.
The explosion was huge and although outside, still caused a lot of damage. I was lucky in that I was standing around 20 feet away. The tanker driver was not so lucky and suffered 2nd degree burns. This is the reason I will never ever do a flour related shoot as I have witnessed first hand on what the outcome could be.
It takes just one spark.
That's why drivers need to follow strict procedures when pumping out, including earthing of the vehicle and the discharge pipes. not pleasant.
Photography by Riddell said, 1500899363
'Dust explosion' as it is called is widely known about, highly studied and with a large portfolio of citable real world accidents that have been documented for at least a hundred years.
Its something you need to consider in any health and safety or risk assesment.
Bob @ Fatbloke said, 1500900367
Never mess with dust and fine powder, which is often highly flammable / explosive.........in a confined space that would probably been quite lethal as explosions do not like to be contained.
MidgePhoto said, 1500900393
Jabberwocky said
Years ago when I worked in the paper industry, I was blown off my feet when a static cable come adrift from a tanker as it was filling a silo with corn flour.
The explosion was huge and although outside, still caused a lot of damage. I was lucky in that I was standing around 20 feet away. The tanker driver was not so lucky and suffered 2nd degree burns. This is the reason I will never ever do a flour related shoot as I have witnessed first hand on what the outcome could be.
It takes just one spark.
Well, no.
An explosion takes either a high explosive or confinement.
A flash fire in a cloud of dust is going to be alarming and not completely hazard free, but the degrees of alarm and hazard depend on the size of the cloud...
Practical point, keep that to no more than is needed.
Sufficiently large clouds will provide their own confinement once they have ignited, as the pressure rises rapidly. Small clouds won't do that, and clouds that are below some critical density won't do positive feedback.
Practical point, ventilate.
The cornflour silo was a bomb, no? Solid structure, big size, fill with mixture of flammable and air, add spark.
Flour mills dispose of hundredweight to tonnes of the stuff.
I prefer not to be around things going whoomph, and even more to not be inside them, but lets not over-exaggerate the danger of small-scale activity.
Practical point, think it through, do it outside or nearly so, keep it damp.
MidgePhoto said, 1500900695
Going from dust to vapour, the US have a rather large bomb, a thermobaric device. As well as the energy of the explosion, it has the property of exploding in a large volume/over a large area of ground rather than at a point, and thus applies force efficiently.
Crisis relocation is the best protection against them.
Could we come up with quantities of powder under conditions which are regarded as not unduly dangerous[1], as an FAQ here?
[1] if we demand things are _safe_ we stop crossing the street, or talking about acts.
Tuppence said, 1500902346
Lightingman said
Tuppence said
Lightingman said
Tuppence said
boundtopleaseme said
Tuppence said
MidgePhoto said
Evaair said
what type of powders are flammable
Anything organic, I'd think.
Not only organic. Try aluminium or magnesium powder!
Please don't try aluminium or magnesium powder.Various powders - coffee creamers and the like - have been used for years in pyrotechnics to create a relatively safe, simulated explosion. Please note the term 'relatively'. It is done by pyrotechnicians, on a small scale, in a controlled method and environment. The actual flame is a conflation of millions of minute powder particles each of which ignites and burns out in a microsecond. The combined effect is spectacular but without any real substance.
Metal powders on the other hand burn at much higher temperatures. They have substance and mass and will do serious damage to people and property.
Admittedly, aluminium powder is an ingredient of thermite, but let's not forget it was widely used in photographic flash photography.I suspect any powder has both mass and substance, so that adds little to the debate.
Aluminium powder was not used in photographic flash photography, the powder was finely divided magnesium mixed, usually with potassium perchlorate, a strong oxidising agent to propagate the burning process.
In pyrotechnics, not photography.
...and was once used for flashes in photography.
Ponderance said, 1500902936
Tuppence said
Lightingman said
Tuppence said
Lightingman said
Tuppence said
boundtopleaseme said
Tuppence said
MidgePhoto said
Evaair said
what type of powders are flammable
Anything organic, I'd think.
Not only organic. Try aluminium or magnesium powder!
Please don't try aluminium or magnesium powder.Various powders - coffee creamers and the like - have been used for years in pyrotechnics to create a relatively safe, simulated explosion. Please note the term 'relatively'. It is done by pyrotechnicians, on a small scale, in a controlled method and environment. The actual flame is a conflation of millions of minute powder particles each of which ignites and burns out in a microsecond. The combined effect is spectacular but without any real substance.
Metal powders on the other hand burn at much higher temperatures. They have substance and mass and will do serious damage to people and property.
Admittedly, aluminium powder is an ingredient of thermite, but let's not forget it was widely used in photographic flash photography.I suspect any powder has both mass and substance, so that adds little to the debate.
Aluminium powder was not used in photographic flash photography, the powder was finely divided magnesium mixed, usually with potassium perchlorate, a strong oxidising agent to propagate the burning process.
In pyrotechnics, not photography.
...and was once used for flashes in photography.
It looks like the first cost-effective flash bulbs were in fact aluminium foil:
https://photography.tutsplus.com/articles/a-brief-history-of-photographic-flash--photo-4249
(That is not a joke image)
Tuppence said, 1500903406
Ponderance said
Tuppence said
Lightingman said
Tuppence said
Lightingman said
Tuppence said
boundtopleaseme said
Tuppence said
MidgePhoto said
Evaair said
what type of powders are flammable
Anything organic, I'd think.
Not only organic. Try aluminium or magnesium powder!
Please don't try aluminium or magnesium powder.Various powders - coffee creamers and the like - have been used for years in pyrotechnics to create a relatively safe, simulated explosion. Please note the term 'relatively'. It is done by pyrotechnicians, on a small scale, in a controlled method and environment. The actual flame is a conflation of millions of minute powder particles each of which ignites and burns out in a microsecond. The combined effect is spectacular but without any real substance.
Metal powders on the other hand burn at much higher temperatures. They have substance and mass and will do serious damage to people and property.
Admittedly, aluminium powder is an ingredient of thermite, but let's not forget it was widely used in photographic flash photography.I suspect any powder has both mass and substance, so that adds little to the debate.
Aluminium powder was not used in photographic flash photography, the powder was finely divided magnesium mixed, usually with potassium perchlorate, a strong oxidising agent to propagate the burning process.
In pyrotechnics, not photography.
...and was once used for flashes in photography.
It looks like the first cost-effective flash bulbs were in fact aluminium foil:
https://photography.tutsplus.com/articles/a-brief-history-of-photographic-flash--photo-4249
(That is not a joke image)
I used to buy Osram Aluminium wool flash bulbs.
PicMix said, 1500903956
MidgePhoto said
Going from dust to vapour, the US have a rather large bomb, a thermobaric device. As well as the energy of the explosion, it has the property of exploding in a large volume/over a large area of ground rather than at a point, and thus applies force efficiently.
Crisis relocation is the best protection against them.
Could we come up with quantities of powder under conditions which are regarded as not unduly dangerous[1], as an FAQ here?
[1] if we demand things are _safe_ we stop crossing the street, or talking about acts.
Thermobaric weapons are a type, not a specific weapon. They also come in very small warheads too. They have different means of working, but originally the point wasn't size but pressure. An initial trigger disperses fuel or explosive into aerosol form, and a secondary charge detonates it whereby the cloud effect allows the air to be used as fuel. It causes more damaging shockwaves and horrendous effects.
it is no coincidence that magnesium, for example, was used in the cloud for various incarnations of the weapon.
There is plenty of footage out there what happens in grain silos, for example, when this type of explosion occurs. It's nasty.
Lightingman said, 1500905172
Tuppence said
Ponderance said
Tuppence said
Lightingman said
Tuppence said
Lightingman said
Tuppence said
boundtopleaseme said
Tuppence said
MidgePhoto said
Evaair said
what type of powders are flammable
Anything organic, I'd think.
Not only organic. Try aluminium or magnesium powder!
Please don't try aluminium or magnesium powder.Various powders - coffee creamers and the like - have been used for years in pyrotechnics to create a relatively safe, simulated explosion. Please note the term 'relatively'. It is done by pyrotechnicians, on a small scale, in a controlled method and environment. The actual flame is a conflation of millions of minute powder particles each of which ignites and burns out in a microsecond. The combined effect is spectacular but without any real substance.
Metal powders on the other hand burn at much higher temperatures. They have substance and mass and will do serious damage to people and property.
Admittedly, aluminium powder is an ingredient of thermite, but let's not forget it was widely used in photographic flash photography.I suspect any powder has both mass and substance, so that adds little to the debate.
Aluminium powder was not used in photographic flash photography, the powder was finely divided magnesium mixed, usually with potassium perchlorate, a strong oxidising agent to propagate the burning process.
In pyrotechnics, not photography.
...and was once used for flashes in photography.
It looks like the first cost-effective flash bulbs were in fact aluminium foil:
https://photography.tutsplus.com/articles/a-brief-history-of-photographic-flash--photo-4249
(That is not a joke image)
I used to buy Osram Aluminium wool flash bulbs.
Flash BULB-FOIL-not powder.
Ponderance said, 1500907092
Lightingman said
Tuppence said
Ponderance said
Tuppence said
Lightingman said
Tuppence said
Lightingman said
Tuppence said
boundtopleaseme said
Tuppence said
MidgePhoto said
Evaair said
what type of powders are flammable
Anything organic, I'd think.
Not only organic. Try aluminium or magnesium powder!
Please don't try aluminium or magnesium powder.Various powders - coffee creamers and the like - have been used for years in pyrotechnics to create a relatively safe, simulated explosion. Please note the term 'relatively'. It is done by pyrotechnicians, on a small scale, in a controlled method and environment. The actual flame is a conflation of millions of minute powder particles each of which ignites and burns out in a microsecond. The combined effect is spectacular but without any real substance.
Metal powders on the other hand burn at much higher temperatures. They have substance and mass and will do serious damage to people and property.
Admittedly, aluminium powder is an ingredient of thermite, but let's not forget it was widely used in photographic flash photography.I suspect any powder has both mass and substance, so that adds little to the debate.
Aluminium powder was not used in photographic flash photography, the powder was finely divided magnesium mixed, usually with potassium perchlorate, a strong oxidising agent to propagate the burning process.
In pyrotechnics, not photography.
...and was once used for flashes in photography.
It looks like the first cost-effective flash bulbs were in fact aluminium foil:
https://photography.tutsplus.com/articles/a-brief-history-of-photographic-flash--photo-4249
(That is not a joke image)
I used to buy Osram Aluminium wool flash bulbs.Flash BULB-FOIL-not powder.
Yes, but Tuppence is right; early flash powder did sometimes use aluminium powder (or a cost-effective mix of mostly aluminium plus some magnesium, a blend which happens to burn brighter).
Magnesium doesn't have any particularly special quality; it's the metal and oxidising agent which is the important bit.
Lightingman said, 1500907447
Ponderance said
Lightingman said
Tuppence said
Ponderance said
Tuppence said
Lightingman said
Tuppence said
Lightingman said
Tuppence said
boundtopleaseme said
Tuppence said
MidgePhoto said
Evaair said
what type of powders are flammable
Anything organic, I'd think.
Not only organic. Try aluminium or magnesium powder!
Please don't try aluminium or magnesium powder.Various powders - coffee creamers and the like - have been used for years in pyrotechnics to create a relatively safe, simulated explosion. Please note the term 'relatively'. It is done by pyrotechnicians, on a small scale, in a controlled method and environment. The actual flame is a conflation of millions of minute powder particles each of which ignites and burns out in a microsecond. The combined effect is spectacular but without any real substance.
Metal powders on the other hand burn at much higher temperatures. They have substance and mass and will do serious damage to people and property.
Admittedly, aluminium powder is an ingredient of thermite, but let's not forget it was widely used in photographic flash photography.I suspect any powder has both mass and substance, so that adds little to the debate.
Aluminium powder was not used in photographic flash photography, the powder was finely divided magnesium mixed, usually with potassium perchlorate, a strong oxidising agent to propagate the burning process.
In pyrotechnics, not photography.
...and was once used for flashes in photography.
It looks like the first cost-effective flash bulbs were in fact aluminium foil:
https://photography.tutsplus.com/articles/a-brief-history-of-photographic-flash--photo-4249
(That is not a joke image)
I used to buy Osram Aluminium wool flash bulbs.Flash BULB-FOIL-not powder.
Yes, but Tuppence is right; early flash powder did sometimes use aluminium powder (or a cost-effective mix of mostly aluminium plus some magnesium, a blend which happens to burn brighter).Magnesium doesn't have any particularly special quality; it's the metal and oxidising agent which is the important bit.
Magnesium is more reactive than aluminium, and importantly aluminium rapidly develops an oxidative layer which especially in a finely reduced form-powder would tend to inhibit reaction significantly.
Ponderance said, 1500907820
Lightingman said
Ponderance said
Lightingman said
Flash BULB-FOIL-not powder.
Yes, but Tuppence is right; early flash powder did sometimes use aluminium powder (or a cost-effective mix of mostly aluminium plus some magnesium, a blend which happens to burn brighter).Magnesium doesn't have any particularly special quality; it's the metal and oxidising agent which is the important bit.
Magnesium is more reactive than aluminium, and importantly aluminium rapidly develops an oxidative layer which especially in a finely reduced form-powder would tend to inhibit reaction significantly.
I think that is why they blended in magnesium to make the cheaper mixture work, but at this point my limited inorganic chemistry knowledge would fail me.
I have always wondered what happened once the metal powder trays began to rust; surely the chlorate corroded the tray, and don't you then have an even more unpredictable mixture once the rust is added in?
(more liberated oxygen during the reaction is my limited understanding)
Edited by Ponderance