On Mon, 20 Dec 2004 16:45:48 GMT, "Bernd" wrote:
"Tim Killian" wrote in message
...
Natural gas from the meter is regulated at 7 inches water column --
about 1/2 psi. If the meter can supply the required volume in cuft/hr,
it will run kilns and furnaces.
I know it will run a furnace since I have natural gas. What I meant is
that I don't believe there is enough pressure and flow to properly run a
"foundry furnace" since you'll need about 30psi to get a flame. That's
my experience with propane for a 5 gallon style furnace and a Ron Reil
burner. So I would think you would need approximately the same amount of
pressure to run on natural gas. The foundry furnace I'm talking about is
al Gingery style. Now the 1/2 psi and a good volume with a blower motor
might work.
Oh, that's what you meant... ;-) Yes, they use the gas delivery
pressure to get forced air induction, the gas drags the air along and
into the burner. You can do the same thing with an electric powered
forced draft blower on the burner to get the air moving, then the low
gas pressure will mix into the combustion air flow.
This is how they build new hot-air furnaces and commercial water
heater & boiler burners for Low NoX, the forced air and gas runs in
"inshot" burners and gives a nice intense flamefront.
You can also use a draft blower in suction on the flue side of a
sealed combustion chamber, but they are more trouble - the blower
wheel is running in the flue gases and corrosion is a big problem.
Note: If this is going to be running unattended for more than a few
seconds, be sure to add a diaphragm pressure switch on the blower
output, and some sort of 'flame out sensor' linked to the gas valve
control circuit. So if the forced draft blower quits for any reason
the gas is shut off automatically.
(A simple low-tech KISS way to shut off the gas is the old standby
Penn-BASO B-60 valve and a millivolt thermopile pilot light [used in
millions of floor and wall furnaces] with the diaphragm switch in
series, or you can get fancy...) ;-)
-- Bruce --
--
Bruce L. Bergman, Woodland Hills (Los Angeles) CA - Desktop
Electrician for Westend Electric - CA726700
5737 Kanan Rd. #359, Agoura CA 91301 (818) 889-9545
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