Belington progressive. [volume] (Belington, W. Va.) 1912-1927, 1924-07-24
LIQUID AIR PLAYS IMPORTANT
PART IN TELEPHONY

"Who said, it's hot?' That's
relative matter. Liquid air will boil
if placed on ice,' F. d. Petty, Man
ager of The Chesapeake and Poto-
mac Telephone Company here offered
as consolation to perspiring scribe
Liquid air." he explained, sis the
coolest thing known and never gets
warmer than 312 degrees, Fahrenheit,
below zero. Consequently if you
put dish Of it on ice, which is about
80 degrees below zero, it is in a hot
place--for liquid air--and will boil
briskly.
! son the other hand, piece of steel
wool, saturated with liquid air will
bNrn freely if lighted with match.
A piece of carbon if heated to red
heat and placed in vessel contain
4 ing liquid air will become white hot,
about 5000 degrees Fahrenheit while
the outside of the vessel will be too
cold to hold in the hand. If the wool
should be saturated with liquid air
and confined, it would prove to be
more powerful explosive than dyna-
mite.
"sWhat has liquid air to do with
my telephone? you may ask, but this
product of science plays an impor-
tant part in radio and long distance
| telephone communication. 1t makes
'long lines longer" and helps to
carry the voice through the ether to
some distant point. In manufacture
ing vacuum tubes for radio and long
distance telephone communication
liquid air is necessary adjunct.
The laboratories of the telephone
company use more than $50 quarts
of liquid air daily in the manufacture
of these tubes that are so necessary
to the transmission of the human
voice over long distance.
"The pumping of vacuum tube
in the telephone ccmpany's manu-
featuring plant is very delicate pro-
cess and employs what might seem
to the untutored observer labyrinth
of glass tubing But every inch and
crook has its purpose. A part OF
this system is composed Of type OF
a type of glass pump using mercury
vapor as pumping agent. 1t is al
so provided with mercury trap in
serted in the system between the
mercury pump and the tubes being
exhausted. This trap is surrounded
! by liquid air which condenses the
mercury vapor, freezing it to the
walls of the trap as moisture is fro
zen on our window panes in winter
time.
"In the liquid air plant, the air is
first compressed to 5000 pounds pres
sure per square inch by four-stage
air compressors. The pressure of the
successive stage is SO, It's, $40 and
5000 pounds for each equare inch.
AS the temperature of the air is in
creased considerably in compression
lit is then passed through two cooling
tanks in which the air passes through
small copper coils which are water
cooled.
1 'The air must be purified before it
passes through the liquefier as inn
purities would CONCEAL in that pro-
cess at much higher temperatures
than the liquid air, thereby stopping
up the passages. The air is accord
lingly passed through series of puri-
flying bottles The first contains
filter which removes any oil or other
foreign matter which may be sus-
pended in the air. 1t then flows
through two bottles containing caus-
tic soda which eliminates carbon
dioxide. The next bgttle contains
water-free granular calcium chloride
and this removes moisture from the
air.
Having reached the proper state
of publication it then passes into the
| liquifier which is contained in tank
packed with Sleeps wool as an in
sulator to keep the heat of the room.
The air then passes through num-
Der of coils of copper tubing and fin
I ally is let out into the tank where
it is directed against the coils though
lit as just come. This reduces the
temperature of the incoming air I'M
til it finally gets down to liquefying
temperature.
Mrs. Lum Hill was taken today to