On Thu, 27 Jan 2005 10:06:13 +1100, "Tom Miller"
wrote:

The whole boiler idea is a bad one. They store substantial amounts of
energy,and even a small one would destroy the average garage, not to mention
anyone standing nearby. There are codes to design boilers.( I think the
American on is ASME section VII) You might read that before you go too far
with your design. Industrial boilers have two safety valves and a control
system to keep the pressure constant as well as a pressure switch which
shuts off the gas or oil supply in the event of the boiler going over its
safe operating pressure. The "Scram" system would probably CAUSE an
explosion as the sudden thermal stresses would cause a fracture somewhere
that would propagate at the speed of sound in steel.


Tom

"pyotr filipivich" wrote in message
.. .
snip

A BLEVE (Boiling Liquid Expanding Vapor Explosion) is a very fast
event, probably no more than a few milliseconds. In that time frame,
anything the size of a propane tank could be considered adiabatic.
You're not going to move a useful amount of heat other than through
the rip in the shell as the water flashes to steam instantly. If it
were cooled starting while it was still far enough below its rupture
pressure/temp, it might work, but there's no way to know for sure at
what pressure rupture will occur.

At a plant that was purchased by the corporation I work for, for years
a ruptured vessel was kept on display. An engineer in the previous
outfit had been in the habit of venting runaway reactions by running
to the reactor and loosening bolts on the manway to vent the reactor.
After a few times where he got lucky, the inevitable happened, and he
was sprayed across the landscape when the manway blew just as he got
there.

The only rational response would have been running away.

Pete Keillor