The Worcester spy. [volume] (Worcester, Mass.) 1898-1904, 1899-02-01

the practice to store in the above men
toned tubes or bottles about so cubic
feet of air in it's cold state After
ward, in using. the air is reheated by
passing through a tank of hot water,
the same as mentioned in connection
| with the Mekarski system. The re-
heating is necessary for two reasons
first. because the air in expanding from
so high pressure. would form ice in the
parts of the motors, and prevent them
| from working; second, because the law
that heat and mechanical energy is
mutually convertible. is operative, and
| the air thus reheated will do nearly
twice the work that it would if used
cold.
In practice, all reasonable effort is
| maze 10 retain and utilize all the heat
possible; the feed water is heated from
the exhaust of the engine Steam
jacketed cylinders, compound cylinders
with experimenting devices and triple
expansion engines are employed for
economy. The whole solution of the
problem is to transmute the potential
energy of the fuel in the shortest, sim
pest transmission possible into work
at the axle or shaft
Compressor builders vie with each
other in the efficiency Of their inter
coolers. wherein the heat may be
carried away as quickly as possible
anywhere to get rid of it. 1t will.
however. have to be supplied again be-
1ore the meter will respond in efficient
work ~
me speaker then described a new
system which he claimed was more
nearly the ideal of the engineer and
railway manager. He described it as
self-contained, Independent motor:
one where 1t was not necessary to re-
turn 10 storage station at short in
terVaIs' as is necessary with the high
pressure systems. In this system the
Go CO. 10 compressed to the working pres
sure only. Not sixteen or more fines
DIS hlgh as is used at the motors. which
pressure Is expensive to secure and dif-
ficult to handle. iA I'll
In using the air direct from the COM
pressor, there is large economy. The
original neat, generated in connnras
SOL Is utilized; FOR in raising the pres
sur 70 the WORKING pressure only, the
temperature of the air Is raised to the
| desired. point for efficient work in the
motors. 10 subStantiate this 7 o1lote
| from very able authority Prof. w. G.
UnWln, the chairman of the Conn
pressed air company at the Columbian
| eApositlon, says in a recent work on
ueVeiopment and transmission Of DOW
! er: Ii compressed air were used in a
motor adjacent to the compressor in IFS
heated state, there would be no neces-
| Sary loss due to rise of temperatl1re
| during compression"
Also the South Norwalk comnanv
builders of air compressors, saw in their
puDllcation: Air during compression
becomes heated, and during expansion
becomes cold; if the air immediately
| aIter compression, before the loss Of
| any heat, We're used in air engine. and
thefe perfectly expanded back to at
mospherlc pressure it would. on being
exhausted, have the same Temperature
IL mad before compression, and it's eff
cheney would be 100 p. c. Simply that
actlon and reaction is equal and oppo-
I site. again they say, as air is COM
| pressed IL rises rapidly i'll temperature
me temperature to which it finally at
talns depends upon the degree of COM
| preston, or in other worcs, the amount
or work expended upon it, testifying
py their practice in compressor build
ing that heat and mechanical energy
are mutually convertible
| The independent system we are con-
slderlng makes possible another source
OF economy direct gift, if so we may
| call 1t. This source Is from the com
pressor brake, an arrangement Whereby
air compressors are operatively connect
ed with the axles Of the truck, in such
manner that when the car Is retarded
| or stopped, the energy ordinarily lost
| 10 operate the air compressor, and the
| air stored for subsequent use. AS It
requires about three times the power
! to start. that it does in the general
| run, the immediate use of the air thus
| gained by simply moving a lever is
very desirable. Thus we have at our
| disposal for useful work, the entire
momentum of car or train less the fric-
ton, whenever we wish to reduce it's
| speed.
The majority of motor vehicles are
propelled from the axle. why not stop
them from the same point?
That the energy due tc the moving
| car or train, is not only available, but
valuable, is illustrated by an estimate
made at the Polytechnic Institute,
April 18th, 1896, in which it was shown
| that the work required to stop train
weighing. say $4,000 pounds, in twice
its length, say 500 feet from a speed
of one mile minute, was 1866 H. p.
applied constantly during period
! of 20 seconds, or 1855 III. P
| for one minute. Illustrations of this
problem can be seen daily. The ele-
waited roads in New York and Chicago
are good illustrations, where the trains
run about one-third of the time on the
brake, drawing from the boiler or cleo
trio supply to apply them. Suppose
these conditions We're reversed and en-
/
cost Of operating would be materially
reduced.
In the introduction of the combna-
ton air compressor, the brake com
pressor finds its largest development,
whatever of heat is lacking, due to in
! termittent operation of the brake. IS
supplied from the exhaust of the i'm
pulse cylinder.
| In the ordinary oil or gas engine,
| quite an amount of heat esca mes
through the exhaust, but in the COM
pressor system the largest proportion
of heat is utilized. The heat from the
impact cylinder supplying the motor
requirements, and the cold produced by
the motors is turned back to do service
at the combustion cylinders. Thus the
exhaust is both utilized and muff1ed.
AS an illustration of this. it is shown
that the exhaust from air motors in
Paris, is used for refi1gerating purposes