John Baymore on mon 24 jun 96
The "thermal mass" of the store of liquid propane can be assisted by placing the
cylinders UPRIGHT (important) in a tub of WARM (not hot.......very important)
water. When the water cools, replace it with more warm water. This provides
the warmth that the liquid needs to make it possible to continue evaporating the
liquid to a gas, so that it can be burned. You can take tanks down to dead
empty this way.
A great source for the water to warm the tanks is the water used to quench the
hot pots. This "recycles" some of the heat energy too, instead of using the hot
water heater! Pour some cold water off of the tank bath, and pour in some hot
water from the quenching bucket (being careful not to pour it ON the tank
directly). Just check the final temp of the water bath carefully.
Tipping the tanks over on their sides is a VERY DANGEROUS practice. Even if you
"know what you are doing", you could get a real suprise on that 1 out of a
hundred time! Sort of like playing roulette. The possible results have already
been mentioned in a recent post. A jet of liquid coming out a burner orifice
sized for vapor can make a very impressive fire!
Using hot water to dunk the tanks or to hose down the tanks is a bad idea.
Pressure int the tank is related directly to temperature of the contents. The
higher the temperature, the higher the pressure. It is possible to raise the
internal tank pressure too far. This can cause the pressure relief valve (or
plug) to blow off a big burst of propane. If there is an ignition source nearby
(burner, glowing pot, cigarrette, or hot kiln), this burst could catch fire and
make sort of a small explosion...... more of a fireball really.
A possible (but very remote) "worse case" scenario of this situation would
involve the rupture of a poorly maintained tank along a rust weakend seam.
That'd make a really big fireball .
It is interesting to note that in my local paper today it was reported that a
trailer cylinder vented due to an "overfill" and the hot weather, was ignited by
a spark from a battery powered screwdriver being operated near it, and the
fireball caused first and second degree burns to all exposed flesh of the two
guys that were by it when it went. Second report of this type that I have seen
in the past couple of months.
Those of us with a lot of experience in a given area need to remember that when
we post a suggestion it is read by a lot of people. Many of those people don't
have the background we do. If we forget a small but important detail that TO US
is something that we have known for so long that we just assume everyone knows
that, it can often cause a problem.
Propane is a useful but dangerous fuel. Familiarity breeds contempt. Just
because you have "gotten away" with doing some procedure for a long time doesn't
make the procedure safe. It just makes you lucky.
.........................john
John Baymore
River Bend Pottery
Wilton, NH
76506.3102@Compuserve.com
http://www.CraftWEB.com/org/jbaymore/rivrbend.shtml
| |
|
