email to office/USCG/media: Yeah, we had a fire
reply: what did you do to control/extinguish it?
Your email back: Well, we were worried about making the fire bigger with hydrogen so we didn’t put any water on it, derp. Some book I read once, with no other citations said water + fire = more fire, derp.
internet searching of various forms of “hydrogen fire” as shown in above book quote yields nothing. Sadly, it appears the book was not peered reviewed.
Another note, the incinerator on board we have shuts the flame off at 950C on the furnace sensor. Surely in the fireball is more than 1000C and the water mix doesn’t seem to explode from hydrogen production…I’d chalk this up to science
The aux boiler stack fire I got onboard a few weeks after, the fire had gone unnoticed for a few hours. The stack pipe was reportedly glowing cherry red where visible, and had gotten hot enough to turn the fiberglass insulation into a molten-like, then solid mass. The fire team ended up climbing the outside of the stack and dropping a hose down. They tried rotating hose teams through cooling inside the fidley but if i remember correctly the confined nature and high heat made that difficult.
In the aftermath we had to cut out and replace almost the entire length of the boiler exhaust stack from the boiler, up through the fidley, to the top of the stack. It was quite brittle. The less enjoyable part was cleaning up from the shower of sea water in the engine room used in the FF effort.
Indeed, separating water molecules into H and O molecules (or Fe to FeO), and reversing this immediately back, does not produce any heat… in an enclosed environment.
However, here we have an open environment.
The gases produced by the initial conversions, even without a clear explosion, expand the volume and search a sortie through the stack to the outer air pressure…
What the micro-timeline exactly is in this process?
I am not a specialist, others may have scientific explanations…
I’ve seen a reference to the MAN paper: MAN B&W Technical paper P280 - 04 - 04
Turns out MAN has an EGB fire simulator.
EXHAUST GAS BOILER FIRE SIMULATION
Occurrence of fire in the EGB and its development has been done on the simulator, “Kongsberg ERSL11 MAN B&W-5L90MC -VLCC Version MC90-IV”, which is installed on the Maritime Faculty in Split
I fought a hydrogen producing boiler fire with associated stack fire along with lagging and various other combustibles in engine room for 6 hours or so. On another ship we deliberately set the aux. diesel stack on fire to burn it out.
In port on shore power with boiler only making hot water but apparently empty so not making steam thus 3 larger burners were put in until it inside looked like Carlsbad Caverns. Not until a few years later when I read the STCW model course for Advanced Fighting Process Hazards did I understand all that was going on.
I used a 150# semi-portable dry chem. System to put on a strange blow torch like blue orange flame shooting 5’ out from a crack in the boiler. Later I learned this is hydrogen gas and should not be put out. After hours of cooling the outside of boiler the last of fire was put out using a solid stream inside economizer. Spray patterns worked for cooling outside of boiler but for direct attack on tubes etc. you need a straight stream with lots of water.
Stack fire was basically surround and drown for hours until it burned itself out, and the only damage was the asbestos block insulation I cut down with a fire axe. Stack was red but it did not seem to ever get to the iron in steam hydrogen fire scenario. By trial and error basically ended up following the STCW method of cooling outside until temp. is below 700C (put wet stuff on the red stuff until it is no longer) while venting the engine room of any gas/heat and only opening up boiler (to prevent oxygen introduction) and then attack with large amount of water in a small area using straight stream vice fog pattern.
On another ship we had 3 large diesel generators aux. power for UNREP winches and fuel pumps with a fairly large stack. Twice flames and chunks of slag came out of stack with the second fueling a carrier and a small fire starting on stack deck, with the carrier getting concerned. Would go out when it was shut down. 1 A/E was adamant he had done it before and knew what to do, so we powered up everything (including fuel pumps) laid out fire hoses and heated the stack up until it burned itself out and problem solved.
" … which is evident from the temperature values after the
second evaporator section (1287.9°C) and the values of temperature after boiler feed water economizer
section (1495.1°C)."
The only evidence I see is that of ignoring the history of technology.
It is evident they have never heard of the “iron age” starting about 3,000 years ago when primitive people discovered they could make iron by heating brown rocks to 1450˚C to 1760˚C by mixing them in with charcoal in a mud stove.
Where did the heat come from to get to 1450 C? From the soot fire? My understanding of the reaction is there needs to be both; the disassociation of hydrogen and oxygen, and the breakdown of steel into ferrous oxides under intense heat. The presence of a deep blue flame would indicate the presence of some other reaction in addition to the one you dictate.
I certainly wouldn’t bet the farm on admitting steam to the soot blowers with a stack fire.
I would imagine most stack fires are burning soot and very few get hot enough to burn the steel. That’s why @MAK was saying only use water when the integrity of the stack is failing (due to burning steel).
I recall the casualty- worked for MSCPAC also at that time… This occurred on the USNS Navasota (or was it Mispillion?) it was direct result of firing a boiler from light off without ascertaining the water level- it was a low water casualty taken to extreme. The self-sustaining hydrogen liberation tube bank fire- although infrequent is well documented through the older boiler books and texts… Was more common on shoreside boilers.
As I recall, the Mid to 8 In-port Watch in Subic was supposed to light off the boiler- checked the Water Glass but didn’t blow it down (although the boiler had been out of service for a prolonged period). I guess after 3 hours of slow- rotating fires (Sectional Header Boiler with a large amount of brickwork)- they still weren’t raising steam pressure- so decided to add another burner!
I sailed as 3rd on the sister ship- Passumpsic in 83 for about 8 months- the problems you describe with the Auxiliary Diesels and the slobbering and resultant stack carbon build up were common- the vessel originally (when built) was about 90’ shorter and had steam recip deck machinery and steam turbine cargo pumps. In 1965 or so she was lengthened and all of the steam deck and cargo pump gear was retrofitted- the deck winches were hydraulic, the cargo pumps vertical electric driven- also the installation of 3 Fairbanks-Morse OP-20’s which were WAY oversized. No load banks, no reduced load settings- so they slobbered constantly below 60% load- they even installed return type by pass dampers to try and raise the intake temp… still though- slobbering pigs…
If it was the Navasota- a real hard luck ship- starboard main engine had a low lube oil casualty… with damage… Then again, my “favorite” one was on the Hassayampa in about 1985- when someone pumped all of the reserve feed water over the side via a bad valve line up- also the DC Heater from what I recall!~ A real mess…
