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On Sun, 27 Jun 2010 13:23:20 -0500, The Daring Dufas
wrote:

On 6/26/2010 12:32 PM, harry wrote:
On Jun 26, 1:09 pm, The Daring
wrote:
On 6/26/2010 3:20 AM, harry wrote:





On Jun 25, 8:42 pm, wrote:
In article
,

wrote:
On Jun 24, 5:41 pm, ddl@danlan.*com (Dan Lanciani) wrote:
Are there auto-changeover propane regulators (or separate
auto-changeover
devices) for fixed (2x 1000 gallon) tanks? The propane company
putting in
my tanks had not heard of this, and Google searches turn up only
ones for
small RV tanks. Ideally something with a remote indicator would be
nice;
I could arrange for the computer to email me to call for a
delivery...

Dan Lanciani
ddl@danlan.*com

Is there a reson you can't use the rv ones? Are you using the same
pressure? I've not seen any with remote indicators though.

there is ONE BIG reason you can't RV tanks on a generator of any
size.
(10Kw) they are Vapor withdraw type tanks and they don't have enough
surface area to allow the propane liquid to boil off into gas,
without
freezing up the tank.... duh... anyone who has ever tried it knows
this...

This is true. We run cars on propane over here. The liquid propane
is vapourised in a heat exchange device that draws water from the
coolant jacket of the IC engine. Many are converted from petrol,
there is an annular ring fitted between the carburretor and the inlet
manifold that injects the gas through a ring of holes. Needle jet
controls the gas on the liquid side of the vapouriser device.

Here, Alabama Gas has been running their vehicles on natural gas for
many years. You can see the CNG tanks on the beds of their service
trucks. Those vehicles have a similar setup to those that run on
Propane.

TDD- Hide quoted text -

- Show quoted text -

Aha. There is a difference .The natural gas is just compressed. The
propane is liquid and has to be evaporated off. I suppose in a warm
climate you might not need an evaporator but even here in the UK you
do.
In the hospital where I worked we had liquid oxygen. It held about
three tons of LOXWe even needed a heat exchanger on that to evaporate
the LOX. It was just like a big car radiator. Even so it used to
freeze up. We had to clear the ice off with a steam lance in certain
weather conditions.

You know, I'm not sure if the gas company is not liquefying the natural
gas, the tanks look very substantial and the technology for liquefying
NG is quite mature. I know some guys who work for Alabama gas and I will
ask them about it. In another thread there was a discussion about O2 and
the tanks. I mentioned the rather large LOX tank at the University
Hospital complex here in town that I want to know more about.

Unlike propane, natural gas can't be in the liquid state at room
temperature,
so must be transported cryogenically or compressed under extreme pressure.
Cryogenics are complicated, heavy, and require energy themselves. A
highly
compressed flammable gas isn't exactly a good vehicle fuel either; not
enough
can be carried safely.

Wrong! Where do you idiots get this information?
Propane liquefies about 150 PSI at room temperature. NG takes much more
pressure.

Mike