Charcoal grills and Liquid Oxygen

[Eric Thelin <eric@generation-i.com>]

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                LIGHTING CHARCOAL GRILLS
                          or
           WHY ENGINEERS ARE THE WAY THEY ARE...
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Our subject today is lighting charcoal grills.  One of our favorite charcoal
grill lighters is a guy named George Goble (really!!), a computer person in
the Purdue University engineering department.

Each year, Goble and a bunch of other engineers hold a picnic in West
Lafayette, Indiana, at which they cook hamburgers on a big grill.  Being
engineers, they began looking for practical ways to speed up the
charcoal-lighting process. "We started by blowing the charcoal with a hair
dryer," Goble told me in a telephone interview.  "Then we figured out that it
would light faster if we used a vacuum cleaner." If you know anything about
(1) engineers and (2) guys in general, you know what happened:

The purpose of the charcoal-lighting shifted from cooking hamburgers to seeing
how fast they could light the charcoal.

>From the vacuum cleaner, they escalated to using a propane torch, then an
acetylene torch.  Then Goble started using compressed pure oxygen, which
caused the charcoal to burn much faster, because as you recall from chemistry
class, fire is essentially the rapid combination of  oxygen with a reducing
agent (the charcoal).   We discovered that a long time  ago, somewhere in the
valley between the Tigris and Euphrates rivers (or  something along those
lines).

By this point, Goble was getting pretty good times.  But in the world of
competitive charcoal-lighting, "pretty good" does not cut the mustard.

Thus,  Goble hit upon the idea of using - get ready - liquid oxygen.  This is
the form of oxygen used in rocket engines; it's 295 degrees below zero  and
600 times as dense as regular oxygen.  In terms of releasing energy,  pouring
liquid oxygen on charcoal is the equivalent of throwing a live  squirrel into
a room containing 50 million Labrador retrievers. 

On Gobel's Web page (the address is http://ghg.ecn.purdue.edu/), you can see
actual photographs and a video of Goble using a bucket attached to a
10-foot-long wooden handle to dump 3 gallons of liquid oxygen (not sold in 
stores) onto a grill containing 60 pounds of charcoal and a lit cigarette for
ignition.  What  follows is the most impressive charcoal-lighting I have  ever
seen, featuring a large fireball that according to Goble, reached 10,000
degrees Fahrenheit. The charcoal was ready for cooking in - this has to be a
world record - 3 seconds.

There's also a photo of what happened when Goble used the same technique on a
flimsy $2.88 discount-store grill. All that's left is a circle of charcoal
with a few shreds of metal in it.  "Basically, the grill vaporized," said
Goble.  "We were thinking of returning it to the store for a refund."

Looking at Goble's video and photos, I became, as an American, all choked up
with gratitude at the fact that I do not live anywhere near the engineers'
picnic site.  But also, I was proud of my country for producing guys who
can be ready to barbecue in less time than it takes for guys in less-advanced
nations, to spit.

Will the 3-second barrier ever be broken?  Will engineers come up with a new,
more powerful charcoal-lighting technology?  It's something for all of us to
ponder this summer as we sit outside, chewing our hamburgers, every now and
then glancing in the direction of West Lafayette, Indiana, looking for a
mushroom cloud.

"Engineers are like that."