It would be poor judgement on my part to throw out specific details during the investigation, but i can describe what went boom and what it does and speculate what COULD go wrong.

in a fluid catalyst cracking unit, (FCCU) a catalyst powder is mixed with oil at very high temperatures and it causes a controlled chemical reaction where the shape and size of the HC molecules are changed from gas oil into gasoline.

That catalyst is then centrifuged out and sent to a large vessel called a regenerator. Hot air is blown into that regen and hits the very hot catalyst (1300 degres F) and it burns off any carbon or impurities that stuck to the catalyst powder. Then the catalyst is re-used in a continuous cycle.

Any catalyst that gets damaged turns into dust and is extracted and carried down a large pipe by the hot air stream, which is now O2 free flue gas. 1300 degrees worth, usually less than 30 psig.

it goes through a boiler where most of the heat is recovered OR through a 25000 hp gas expander (like the free turbine of a jet engine) the flue gas goes up the stack to atmosphere. But it must be cleaned really good first.

That's where the boom comes in.
There are a series of very large metal boxes that the flue gas goes through. They are called electrostatic precipitators (ESPs).
They use high voltage electrical charges to create a strong static charge on thousands of rods or grids inside the box, and any dust or solids in the flue gas sticks to them.

Periodically they are "flushed" where the dust falls to the bottom and is collected in bins as a waste product.

Now, these ESP "boxes" can be huge. 60 feet tall, 30 feet wide, 50 feet long, or larger.

Now imagine hypothetically the process unit was shut down and cleaned for maintenance. No flow through the ESPs.

Now imagine that a box that size that was accidentally filled with a flammable gas from an unexpected chemical reaction, and had just enough air in it to create a perfect mixture for combustion: not to too lean, not too rich.
And no one realized it.

Then imagine hypothetically during maintenance testing, the ESP was energized and created static discharge inside the box.
What could go wrong?



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I've heard of dust explosions in grain silos, or was it flour mills.
(Maybe someday we'll have transportation running off powdered fuel sticks.)

Opal
http://forums.pelicanparts.com/uploa...1424460008.jpg

Here's a "before" pic: (similar design, but smaller)

http://forums.pelicanparts.com/uploa...1424460013.jpg



and ....... after:

http://forums.pelicanparts.com/uploa...1424460120.jpg

Both

Obligatory pic
http://forums.pelicanparts.com/uploa...1424460385.jpg
Jammer-Time - not that I would turn the sandwich down - an extra 1/2 hr on the elliptical trainer should alleviate some of the caloric hyper-load.

Cheers
JB

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Rosie O'Donnell, is that you?

(smellin' like toonaa. deeelish!)
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Iffn he's gonna ride that motorcycle, shouldn't he be headed towards this?

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Great pic! Makes me want to ditch the office.

I took the family over there last summer and arrived on the bullet train in 40° celsius (104° for you yanks). MC riders absolutely bombed the place. Lane splitting, closing speeds of 50MPH+, riding 3 abreast. The Arc de Triomphe has 12 arterial streets converging at the hub of the Arc. Riders would enter heavy traffic already in the roundabout at 50MPH. I watched in amusement/amazement and it all worked out; drivers gave way, MCs somehow found space and I didn't see one crash.

Gratuitous pic of a couple :rolleyes: of my machines...

http://forums.pelicanparts.com/uploa...1424466533.jpg

1968 911S Soft Window Targa…Original color Bahama Yellow.

CAAA-CHING! :eek:

http://forums.pelicanparts.com/uploa...1424481403.jpg

Yours, Craig?

https://scontent-mia.xx.fbcdn.net/hp...2f&oe=5552AA80

Where is that taken? Don't think that's in Paris. There are lots of replicas.

It will be Baz…Just as soon as I win the Powerball Lottery or some long lost rich uncle leaves me some money. She's WAY over my head.


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Thanks for the breakdown. I didnt realize the process worked this way.

Is the catalyst powder dangerous/toxic when exposed to the environment? I assume that's what all the dust/ash is lying about? Should I tell my friends nearby to head for the hills, so to speak? I drove by that refinery nearly every day for years.



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