Boiler Explosion

[rajant2001]

ONE 45 TONS/HR SPREADER STOKER FIRED BOILER HAD AN EXPLOSION WITH A BIG NOISE CAUSING FURNACE WATER WALL DAMAGE.

DETAILS ARE AS BELOW:

BOILER PARAMETERS 45 TONS/HOUR; 65 KG/CM2; 490 C

FUEL - EUCALYPTUS BARK.

TYPE – BALANCE DRAFT (-5mm) WITH TRAVELLING GRATE

AUTO CONTROLS – 3 ELEMENT FEED WATER CONTROL, STEAM TEMPERATURE CONTROL, COMBUSTION CONTROL, FURNACE DRAFT CONTROL

CONTROL SYSTEM – DCS

IT IS UNDERSTOOD FROM LOG SHEETS AND OPERATORS THAT DURING THE PERIOD OF EXPLOSION:
FUEL FEEDING WAS MANUAL AND ALSO EXCESSIVE FUEL FEEDING WAS DONE
FURNACE PRESSURE WAS CONTNUOULY POSITIVE TO THE EXTENT OF +5mm
ANALYER INDICATES HIGH OXYGEN CONTENT IN FLUE GAS (MAY BE INSTRUMENT ERROR)

THE FORUM CAN EVALUATE/DISCUSS THE ABOVE PROBLEM ON:

WHAT COULD BE THE REASON FOR THIS EXPLOSION IN A STOKER FIRED
BOILER WITH BARK FIRING?.

WHAT ARE REMEDIES/PRECAUTIONS TO BE TAKEN TO AVOID FUTURE OCCURRENCE OF THIS KIND OF EXPLOSION?

 

[athomas236]

At some stage it might be worth while comparing the design of your combustion system with the requirements of NFPA 85.

Regards,

athomas236

ps
It might also be worth while turning the caps lock off

 

[macmet]

Was it actually the boiler that exploded or the combustion chamber itself?

 

[StoneCold]

Macmet
I was wondering the same thing. Was it a tube rupture event or did unburned offgas from the eucaliptus feed material build up and then explode? That would be helpful becuase it could just be tube overheating or tube thinning.
How old is the boiler? That might also lead us to some conclusion about the problem.

Regards

StoneCold