Skip to comments.Two explosions at flooded Texas chemical plant: Fifteen police officers hospitalized after blast...
Posted on 08/31/2017 5:35:36 AM PDT by Rockitz
Two explosions have occurred at a chemical plant outside of Houston, hours after a spokesman warned a gas explosion was imminent.
The explosions came after The Arkema Inc plant in Crosby, Texas, lost power and its backup generators amid Harvey's days-long deluge, leaving it without refrigeration for chemicals that become volatile as the temperature rises.
Just after 2am local time, the Harris County Emergency Operations Center reported explosions at the plant and black smoke rising from the facility.
The Harrison County Sheriff's Office said that at least one officer had been taken to the hospital after inhaling fumes following the explosion.
'One deputy taken to hospital after inhaling fumes from Archem (sic) plant in Crosby,' the HCSO said in a tweet. '9 others drove themselves to hospital as precaution.'
Arkema said in a statement that more explosions could take place in the coming hours or days and warned residents not to return to the area until it has been cleared.
The plant said in a statement: 'Organic peroxides are extremely flammable and, as agreed with public officials, the best course of action is to let the fire burn itself out.
'We want local residents to be aware that product is stored in multiple locations on the site, and a threat of additional explosion remains. Please do not return to the area within the evacuation zone until local emergency response authorities announce it is safe to do so.'
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Two explosions at flooded Texas chemical plant: Fifteen police officers hospitalized after blast at facility that will get MORE dangerous as the water rises
If only someone had told them that a hurricane was coming...
This will burn for awhile.
Hopefully, no KABOOM.
Yeah!! Because they could’ve built up the necessary infrastructure in the four days notice we had!!!
Actually, facilities like these are required to plan of a 100 year rain event.
This event is way beyond that. Holding the company responsible for meeting federal guidelines is one thing...holding them responsible to an act of god?
The appropriate course of action is exactly what they are doing.
Some metals (Titanium particularly) make great fuels in the presence of an aggressive oxidizer. Hopefully leak before burst for these bottles.
A faint hope given it's organic peroxides.
A burst is going to happen. No way to stop it now. The hope is to make it go like a roman candle as opposed to a M80.
Eventually, the tank will fail from the heat. Peroxides will burn under water (well, many of them will), so this is about protecting some of the area, no longer about asset preservation.
I just watched a report on FNC and there was no mention of any injuries.
I saw a report on ZH that said that 9 of the officers drove themselves to the hospital. Doesn’t sound too bad yet.
Leak before burst describes a pressure vessel designed such that a crack in the vessel will grow through the wall, allowing the contained fluid to escape and reducing the pressure, prior to growing so large as to cause fracture at the operating pressure.
Many pressure vessel standards, including the ASME Boiler and Pressure Vessel Code and the AIAA metallic pressure vessel standard, either require pressure vessel designs to be leak before burst, or require pressure vessels to meet more stringent requirements for fatigue and fracture if they are not shown to be leak before burst.
I suspect these tanks are so small as to not be classified as pressure vessels and are more like simple containers. That would limit their size so hopefully any explosions will be small and distributed over a long duration of time.
I guess I meant KABOOM in a “technical” sense. Like Marvin the Martian saying “Where is the KABOOM? I wanted an earth shattering KABOOM!”
But, you are probably right. The fact they pulled out and are letting them burn means we have reached the point were you are trying to contain the event, rather than stop it.
Another reason I am a very paranoid man with my processes. I hate KABOOMs.
Depending on where they are in the process, they may be pressure vessels.
Not quite sure. If they are just regular pressure vessels, that would be worse as they will pop, not split.
Yes, it’s amazing that relatively so few have been injured or died.
Well, the plant did provide a warning a few days ago that the plant could explode.
Me too, I’m a process engineer...
Yeah, but they also said nobody would be injured.
LOL. Chem E by training, Process by trade.
An old boss once said “Red. Do you sit up at night and think about what will kill your process?” “Yes sir, I do.”
Murphy and his gremlins are active little buggers. All we can do is kill the ones we can plan around.
IIRC, existence of one or more pressure relief valves meets the spec. The valves allow a controlled release of stored material to stabilize containment pressure.
Once released, that material may ignite, but that is secondary to keeping the tank integrity.
The danger is when fire outside the containment vessel is up against the vessel wall. In such a case, the fire outside the tank will simultaneously heat both the tank wall and the material inside the tank. As long as the level inside the tank remains ABOVE the level of this heated zone the material itself will absorb the heat, and tend to keep the temperature of the vessel wall below a temperature at which it might fail. If the fire goes on long enough to boil off the contained material until the level gets down to where the heated zone is, the tank wall temperature will rise rapidly to a point where the strength of the steel falls below the set point of the pressure relief valve(s). Under those conditions the tank wall will burst, and the vaporized material inside the vessel will be forcibly expelled directly into the fire until internal tank pressure drops below external atmospheric pressure.
If that material is flammable, it will convert a burning fire into a massive blowtorch until the tank pressure falls below atmospheric. The rate of release will cause material to exit the ruptured tank so quickly that it will not just suddenly stop when internal pressure equals external pressure, but will overshoot, so there will be a moment of pressure reversal that will cause the tank to suck back and draw burning material back into the tank.
THAT is when the BIG KABOOOOM will happen.
What vaporized material remains inside the tank — IF its molecular structure includes oxygen enough to support self-combustion, as is the case with peroxides — will ignite instantly causing a pressure spike that will act upon the area of the existing tank rupture with such force as to completely tear the rest of the tank apart.
This is called a BLEVE (ble-vee) and is the most dangerous situation possible with flammable materials under compromised containment. Pieces of the shattered containment vessel can be hurled through the air to astounding distances.
This subject-specific video is instructive:
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