Antiques & The Arts
Antique Soda-Acid Fire Extinguisher: Recharging and Operating

Antique Soda-Acid Fire Extinguisher: Recharging and Operating

A young housewife is frightened by a
sudden fire. Being a woman she’s in a state of panic
and her life is in danger. Luckily a local boy notices the fire
and runs for the nearest call box. The fire extinguishing apparatus is a new
development that allows a trained professional to avert disaster. The
proper steps in the use of the fire extinguisher can be easily remembered by
the familiar word fudgel. Fetch the fire extinguishing apparatus and approach the
conflagration. Up-end the apparatus with alacrity, this is no time to be tentative
lives could be at stake. Direct the hose nozzle towards the base of the fire. Give
the involved area a thorough going-over. evacuate the remaining carbonic acid gas
by returning the apparatus to an upright position. Look carefully for any
remaining flames or embers. Fudgel, a useful word that could save a life. Thanks to this new invention and the
swift actions of our local heroic firemen a young housewife can sleep
soundly tonight. . . after she finishes making dinner. So I recently acquired
this soda acid antique fire extinguisher and a lot of people like to polish these
up and use them as decor but since this one seems to be in working condition I
thought I’d charge it up and try it out. Directions for charging- fill bottle half
full of sulfuric acid, 4 fluid ounces. Place stopper on same and fasten into
cage. Dissolve one and a half pounds bicarbonate of soda into two and a half
gallons of cold water. Pour into extinguisher to filling mark. Screw cap
down to washer all right so this is how it works it’s
got this little glass bottle that you fill up to that mark with sulfuric acid
and it’s got a lead stopper in the top when you turn the extinguisher upside
down the lead stopper falls out and the sulfuric acid mixes with the sodium
bicarbonate and water and produces enough carbon dioxide to propel the
water out of this little guy. I should note that the name of this
channel, Chemical 14, refers to the fire company Chemical 14 which was once
stationed in this building along with Phoenix 8 pumper. A chemical company was
essentially a giant soda acid fire extinguisher with carriage wheels that was hand pulled to the scene of a fire. it could then be activated either
by flipping it upside down or sometimes by breaking a glass vial that contained
sulfuric acid. I’m not sure how long chemical 14 was in service here but this
was a fire station until the mid 1960s. One of our chemist friends suggested
that instead of using sulfuric acid we use hydrochloric acid since it might be
a little safer. Both reactions result in carbon dioxide gas so both will work.
The extinguisher calls for four ounces of sulfuric acid so we had to figure out
how much hydrochloric acid we needed. One molecule of sulfuric acid reacts with
one molecule of sodium bicarbonate to form two molecules of carbon dioxide, two molecules of water, and one molecule of sodium sulfate. One molecule of
hydrochloric acid reacts with one molecule of sodium bicarbonate to
produce one molecule of carbon dioxide, one molecule of salt and one molecule of
water. So molecule for molecule the sulfuric acid reaction is twice as
efficient as using hydrochloric acid. Using the magic of Avogadro’s number
and dimly remembered chemistry classes, getting the same reaction from 31% of
hydrochloric acid as 95% sulfuric acid would require roughly seven times as
much hydrochloric acid. Since the bottle in the extinguisher
would only hold about eight ounces total at best we’d only be generating about
1/3 as much carbon dioxide. Is this a problem? Probably not for us since we’re
just trying to spray some water and not blow the lid off an antique fire

5 comments on “Antique Soda-Acid Fire Extinguisher: Recharging and Operating

  1. Don't forget to Hydro static test that tank , if it fails – blows up at 100psi
    [ while in use ] then
    you have a real problem in your hands.

  2. Soda acid extinguishers were banned in 1978 because they are dangerous and have killed and maimed people. To sugest that you can recharge these is irresponsible. Way to many things can go wrong, such as mismatched lead stoppers and caps. the stopper was matched to the concave in the cap to regulate the amount of acid mixing with the soad mixture. Too much acid too fast and too much pressure, BOOM! Cylenders are more often weakened along the seams and especialy on riveted seams and should never be pressurised.

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