View Full Version : my woodboiler imploded
04-12-2010, 09:45 PM
it's been a CraZy week:bear_noexpression:
I noticed a small water leak in the main loop; at a circulator
so I shut off the isolator handles planning to fix the leak asap
it was warm for a few days,
but it got cold Friday night
so I lit a fire,
forgot about the valves that I shut off a few days before:withstupid:
Woke up to a LOUD explosion/implosion and fire alarms:shocked_ma:
The house was filled with smoke and soot.
Hot coals all over the floor, soot & dust over everything
The pressure relief valve should have taken care of this
but it failed to relieve the pressure.:hmmmm:
The boiler actually imploded inward crumpling the interior which is 1/4" boiler plate.
It's like loosing an old friend, I have been tending this boiler for about 12 or so years. Sometimes a small oversight can create a big problem,
be careful out there :help:
04-12-2010, 09:50 PM
Dang! You are lucky to be alive!
Steam is extremely powerful... 1/4" plate no less...
Pressure relief valve must be defective....
dirt to oil
04-12-2010, 10:58 PM
Have you seen the episode of myth busters where they rig a hot water tank to go by pluging the relief valve . it gooes through the roof and on for 50 more feet. You were very lucky no one was hurt , steam is something you don't mess with 1 gal. water = 1700 gal. of steam
04-12-2010, 10:59 PM
Wow, Lucky you still have a house to type that from. I am curious as to how the main boiler would have imploded when my expected method of catastrophic failure would be explosion? Maybe after the first burst of steam escaped the remaining rapidly condensing steam could create enough vacuum to cause the already stressed boiler to implode? Stay safe out there.
04-12-2010, 11:01 PM
Maybe after the first burst of steam escaped the remaining rapidly condensing steam could create enough vacuum to cause the already stressed boiler to implode? Stay safe out there.
that would be my guess too...only one that makes sense...rapid vacuum
04-12-2010, 11:27 PM
It crunched the inside of the boiler inwards
so the water / steam went into the coals and extinguished most
blew the door open and shot the ash out against a masonry wall
we are just about all cleaned up now, and surprisingly the smoke smell has gone
now the search is on for a more modern boiler with higher efficiency / a Tarm ? or Budarus?
it was user error that was at fault here, I know the system well and have used it for years
sh*t happens..............so you deal with it
04-12-2010, 11:31 PM
Did you manually open the relief valve and flush the valve seat before start-up this fall ?
Its an operator requirement prior to start-up for commercial boilers, if the pop-off isn't flushed hard water deposits will eventually seize the mechanism.
Oh yeah, BTW, I'm a boiler operator.
04-12-2010, 11:34 PM
happily 'someone' was looking out for ya, I would have expected explosion also
04-12-2010, 11:40 PM
The boiler explosions I'm taught about is a failed flame safeguard leading to false ignition trial confirmation, main gas valves open and gets a spark.
This is usually from jackleg mechanics presidentially engineering the controls ...
Usually blows the burner door off a Scotch boiler ... and through the boiler house walls ... and the next builder over ....
04-13-2010, 12:12 AM
I replaced the relief valve about 3 or 4 years ago and do flush the valves when starting the system up each year
it still failed to relieve the pressure
I think air probably got into the system from the circulator leak,
so the boiler was not cooled sufficiently because of air/ lack of water
I only lit a small fire in it, which was had burned down to mostly coals when the event happened
so the house had warmed sufficiently with no zones calling for heat
a zone finally called for heat and sent cool water into the low on water / hot boiler:egg:
many of the boilers now have a pop out plug that is similar to a freeze out plug in an engine block inside the firebox so it would blow into the firebox and extinguish any fire. The boiler I had at least was designed stronger on the outside than inside so it also extinguished most of the embers, just glad I wasn't down there when it happened:5123:
04-13-2010, 07:51 AM
Solid fuel (wood) boilers are unique animals with their own characteristics. Tarm recommends the use of a mechanical mixing valve before the house loop ties to the boiler. They recommend the Termovar: http://www.termomix.co.uk/termovar.html
Using this prevents water from circulating into the house loop untill it is up to temp and water coming directly back to the boiler that is cool enough to shock the boiler. Tarm used to use electrically controlled 4 way valves that would take + - five minutes to open. Using these would also prevent shock as the return water was tempered by the valve opening soooo slowly.
04-13-2010, 09:21 AM
I use an outdoor wood boiler, (Click for link (http://www.centralboiler.com/home.html)). It works in conjunction with my indoor gas furnace. Some areas may restrict their use, as they put out lots of smoke when your water temperature is building. It actually heats both my house and my son's across the drive.
04-13-2010, 05:27 PM
For those asking the wood stove is a water jacketed device air outside/metal/water/metal/firebox inside.......the water built up pressure and the force of the steam collapsed the firebox to the inside to relieve pressure.......much like it is easier to crush a pop can from the outside than the inside...envision a beer can inside of a beer can with water inbetween
so it really wasnt a implosion it was a explosion to the inside fire box which by design would be first thing to go instead of the outside jacket
this post is for those above that were suspecting vacume etc.
most of the wood boiler designs in this area that i am aware of have open to atnosphere water systems with auto water level fillers etc....much safer
we see a lot of these http://www.outdoorwoodfurnaceboiler.com/
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