Date: Mon, 10 Jan 2000 00:34:21 -0600
Reply-To: John Rodgers <inua@SCOTT.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <inua@SCOTT.NET>
Subject: Re: Coleman Plat Cat Heater Report
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Catalytic heaters have been around since at least the early 70's and maybe
earlier. I remember way back in 1969 and the early '70's when I was a bush pilot
in Alaska, using small catalytic heaters to pre-warm engines during very cold
weather.
In the early years, even into the 1960's, it was a common thing to drain the hot
engine oil at night into a bucket and haul it into the shop or cabin at night. In
the morning the oil bucket was put on the stove and heated downright hot, then
carried to the plane. The hot oil was poured in and the heat of the oil
transferring through the engine would loosen things for a start.
You have to realize that 50wt oil at 45 degrees F below zero was stiff enough for
one to do chin-ups on a horizontal propeller blade, and the blade not move so
much as a fraction of an inch.
Other airplanes I flew had a fuel injection button in the oil system, and using a
table marked with time in seconds and outside temperature in degrees, depending
on how cold it was, I would press the button with the engine running and gasoline
would spray into the oil system, thereby diluting the oil so it would be thin
enough(low viscosity) for a cold start the next day. Once started the next
morning, it was idled sufficiently long to evaporate the fuel from the oil before
take off. Quite an experience.
The advent of the small catalytic heater was salvation. Insulated engine cowling
covers were used and those little catalytic heaters, often carried in the
airplanes, unlit of course,and with the cover over the wick and platinum
converters, were hauled out when operations were shut down for the night.
The heaters were little things, and would fit right up under an engine in the
engine compartment. It would be filled with coleman fuel, lit off, and placed
under the engine inside the couling, usually resting on a part of the engine
mount. The engine covers were thrown over the cowling and closed up tight. Next
morning, it was pull the covers, pop out the Cat. heater, pull the engine through
by hand a few times, then fire the engine up. It was then allowed to idle for a
while to warm up thoroughly before starting out. Nothing worse than some oil
being free flowing enough to show oil pressure, and the rest still a hard
miserable lump. Under those circumstances, a sudden, extended rev of the engine
would result in oil starvation of the bearings and subsequent engine failure.
Watched a hot-dog pilot do just exactly that one day. He was in a rush, didn't
let the engine warm sufficiently, and the engine seized about 300 feet in the
air. He managed to plunk it down right side up in the dingweeds off the end of
runway. The hot-dog survived the landing, and the damage to the plane was
eventually repaired, but the pilot seat was damaged beyond repair and had to be
replaced.. They were unable to remove the cone from the seat where he was
sitting.
Yep, catalytic heaters have been around a while.
John Rodgers
"88GL Driver in Alabama
Joe Ernest wrote:
> At 06:42 PM 1/7/00 -0800, Davidson wrote:
>
> >>>>
>
> Wendy & John, I don't believe the catalytic heater had been invented
> twenty years ago.
> >>
> Please consider that pollution controls and automotive catalytic converters
> were introduced over 25 years ago to promote a very similar reaction, if for
> a different purpose. Platinum's use as a catalyst and as an electrode goes
> back many decades further in the world of chemistry and industry. Catalytic
> heters were around back then. Similarly, mantles of many lanterns since World
> War 2 used another heavy metal to achieve increased light output.
>
> I also own an avacado green 'mushroom' Coleman catalytic heater that operates
> on Coleman liquid fuel. I also have two other 70's vintage propane fuelled
> catalytic heaters.
> As I understand it, the big advance in recent years has been in the design of
> the substrate/carrier for the catalyst.
> Early 'wicks' were very physically and functionally delicate, prone to
> fraying and plugging which lead to incomplete combustion, odours and
> headaches.
>
> JoE
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