The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1899-03-25
An Expert Writes on Use Of
Compressed Air.
ADAPTED TO SURFACE TRANSIT
Its Numerous and Varied Advan.
tages-Progress Made With
In Past Few Years.
BY II. \. Allen.

by III. y. Allen.
Mechanical and Electrical Engineer
During the last two or three years.
the mechanical world has been much
disturbed by the great advances made
in motive power machines by the use
OF high pressure compressed air. We
are all more or less familiar with what
is termed water" and its uses In gen
eral. For steam-power purposes. IL Is
fed into a boiler and there, by the ad-
dition of heat, changed from n liquid
fluid into gaseous one; from n prac-
tically non-compressible substance in
to an elastic one, called steam" In
this last form, by reason of the heat II
contains and the property OF expansi-
bility common to all gases. IL is used
to drive the engines that run our mills
our factories, our continent-spaanins
trains and the greyhounds OF the
ocean.
Air is also a gaseous fluid. 1t can
be heated. Directly or indirectly by
pressure. Thus II can be used IN n
manner similar to that OF steam 10
drive machinery. Air. under high pres
sure, is far less dangerous in case OF
bursting of the containing vessel than
is steam. 1t will escape from the rent
in the vessel with a Kissing sound, but
niann= nf hn n
as would be the case in n steam boiler
explosion, where the sudden reduction
of pressure causes the water to flash
instantly into steam, increasing the
volume more than one hundredfold.
The scllding effect of steam. in the
large majority of cases, causes greater
injury than the. direct effect of the
explosion.
Compressed air has been used for
more than n century to run machin-
cry. 1t is used universally in mines for
the running of pumping engines.
hoists, rock drills, and underground
locomotives. Here it has one great ad-
over its two rivals. steam and
electricity, that is. besides operating
more economically, the air exhausting
in the mine forms a most complete
system of ventilation. For the run
ming OF large engines. such as pumps
and mill engines, IL is more economical
than its rival, electricity, with its ap-
paratus. One of the most notable long
distance transmiSsions OF air Is that
at the Chaplin Mines, Iron Mountain,
Mich. Here the water power afforded
by the Quinessec Falls Is made to
develop two thousand horse power in
compressed air. The air is led through
three and one-half miles of twenty
four inch pipe to the neighborhood of
the mines. Here smaller pipes are used
to conduct il to the various mine
shafts and the various machine shops
belonging to the Company. The long
est lead is about four miles. where 1t
is used TO drive a large Fraser *
Chalmers pumping engine, capacity
POO gallons per minute approximate
ly three million gallons per twenty
four hours TO a head OF 1850 feet. An
efficiency of more than 90 per cent is
Obtained at this mine with we'll de-
signed engines, without any form of re-
heating aevice. his is all the more
remarkable when il is taken into coI-
sideration that the air pressure ut the
air power plant is but siXty-two
pounGs, the air plant having been in
sailed more than eighteen years ago.
Were such a plant installed today, n
pressure of not less than two thousand
pounds per square incn would be used
with a large gain in efficiency.
The question is often asked: Why.
then, if compressed air has been so
successful. has electricity obtained
such a foothold?" This can be very
readily understood IL one is familiar
with capital. The large amount Of
money expended on the ch-merical
Keely motor is a matter OF current his
tory. When electricity first came into
prominence, it was looked upon as al
most a supernatural agent. IL was
predicted that there was nothing that
could not be accomplished by its use.
The acknowledgements crank called IL
Fluid of Life Vital Force" and
claimed it was the long sought for
Cure-all. Large fortunes were made
and lost on various electrical devices.
both good and bad. 1t being something
new, il became a fad. II has, however
reached a limit similar to that OF
steam. New discoveries in electricity
are now few and far between. The
efficiencies at first claimed by its use
have failed To be verified and the
world once more is looking for some
thing better. Economy in operation
smaller cost of the coal pile, is now
the cry OF the progressive business
man. To obtain the same Is the aim OF
the inventor and the experimental
Once more their attention is directed