This is by George Dickson, of Toronto, Canada, and David Alanson Jones.
A mixture of water and liquefied carbon dioxide upon being discharged
through pipes at high pressure causes the rapid expansion of the gas and
converts the mixture into spray more or less frozen, and portions of the
liquid carbon dioxide are frozen, owing to its rapid expansion, and are
thus thrown upon the fire in a solid state, where said frozen carbon
dioxide in its further expansion not only acts to put out the fire, but
cools the surface upon which it falls, and thus tends to prevent
reignition.
A represents a receptacle sufficiently strong to stand a pressure of not
less than a thousand pounds to the square inch.
B B water receptacles.
[Illustration: Fig. 1]
In the drawings we have shown two receptacles B and only one receptacle
A; but we do not wish to confine ourselves to any particular number, nor
do we wish to confine ourselves to the horizontal position in which the
receptacles are shown.
C is a pipe leading from the receptacle A to a point at or near the
bottom of the receptacle B.
F is a pipe through which the mixture of water and liquefied gas from
the receptacle B is forced by the expansion of said liquefied gas, the
said pipe taking the mixture of water and liquefied gas from the bottom
of the receptacle.
[Illustration: Fig. 2]
To use the apparatus, open the stop cock D in the pipe C, leading to one
of the receptacles B, whereupon, owing to the lower pressure in the
cylinder B, the liquid carbon dioxide expands and rises to the top of
the cylinder A and forces the liquid carbon dioxide into the cylinder B,
the same as the superior steam of a boiler forces the water of the
boiler out when the same is tapped below the surface of the liquid. Now
upon opening the tap H, this superior gas forces out the mixture of
water and liquid carbon dioxide, which suddenly expanding causes
portions of the globules of liquefied gas to be frozen, and these, being
protected by a rapidly evaporating portion of the liquefied gas, are
thrown on the fire in solid particles. At the same time the water is
blown into a spray, which is more or less frozen. The fire is thus
rapidly extinguished by the vaporization of the carbon dioxide and water
spray.
* * * * *