I helped replace one like this with similar damage in Chicago years ago....It was a delayed ignition....like 3 minutes. I did not know then that three minutes worth of gas at 75 inches of pressure could do that much damage. The boiler, another CB, had so much damage to the vessel itself, it had to be scraped. They never could place blame on the maint. staff, as they were all killed in the blast.
Originally posted by Noel Murdough I saw another angle picture of it. The back oven door is swinging partly open on it's davits.
I wonder what part let go. Perhaps a tube blew out???
If I ever see a B.L.E.V.E. (boiling liquid expanding vapor explosion), I want to be far away from it...
Just a guess probly low water caused the crown sheet to let go. When that happens it is like a balloon when you let it go. looks like they got away without a lot of damage. Normally when that happens the gas line breaks and then then you get a secondary explosion and ffire.
Originally posted by no8no3 I helped replace one like this with similar damage in Chicago years ago....It was a delayed ignition....like 3 minutes. I did not know then that three minutes worth of gas at 75 inches of pressure could do that much damage.
Boilers dont explode from delayed ignition, the most that will happen is that the flue pipe will get blown off the vessel and a loud rumble will be heard.
Gas in a boiler gets vented out through the flue by draft or combustion fan. Not enough pressure could be built inside a vessel to cause it to rupture.
On the other hand when water is pressurized and then subjected to a drop in pressure (atmospheric pressure) it boils off fast and expands at an incredible rate. This expansion creates enough internal pressure to blow anything apart and is the main cause of boiler explosions.
The boiler pictured above must have been exposed to a massive drop in pressure which caused all the water at high pressure high temperature to boil off simultaneously.