Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1891-08-15
A NEW MOTIVE POWER
Steam and Heated Air Combined Is
Better than Steam Alone.
PERHAPS A REVOLUTION AT HAND
By Preventing Waste Gain of "A Per Cent
in Power is Secured.
CLAIMS ARE PROVED BY EXPERIMENT.

for it, says the London Times The mechanical
work done by pound of coal in our best
englnes-thao is, by the conversion OF heat
into motion-is greatly less than theory
tells us it should be. 1t has been proposed
to supersede steam by various gases or to
add them to it and use them in a mixed
form. Air has found much favor with in
ventors, and there have been times when
the use of combined air and steam appeared
to be practical method of improving the
steam engine. But apart from gas engines
and hot air engines pure and simple, down
to the present time there has been no record
OF commercial or even practical success
having attended the introduction of air IN
any way into the steam engine.
Among others who have taken deep
practical interest in the question of the use
of combined air and steam in the engine is
Mr.. Edward Field, c. E., who has been
well known for many years past in con-
nection with the steam boiler bearing his
name.
A DISCOVERY, NOT AN INVENTION.
His improvement was a great step in ad-
vance in the steam boiler, but it is probable,
far greater advance in the engine by in-'
creasing its efficiency and economy in
very remarkable degree. And what he has
really done partakes rather of the nature of
discovery than an invention,
Put in a few plain words Mr.. Field
produces the volume of mixed gases under
pressure necessary for performing a given
amount of work in an engine with the use of
only from 1914 to 20 per cent of the quantity
of steam which would be used in the same
engine to perform the same amount of work.
This volume of mixed gases consists of a
small volume of steam introduced into q
large volume of heated air. Whatever Of
invention there is in the present connection
relates to the apparatus by means of which
the discovery is utilized in practice. This
apparatus consists of two portions-namely,
the experimental, whereby Mr. Field demon,
strates the principles of his discovery, and
the practical, by which he illustrates the ap-
pEcation of those principles in doing work.
This apparatus of both kinds we have
recently had the opportunity of inspecting
and of seeing in operation with results
which fully support all that Mr.. Field
claims in respect of the principle. The ex-s
perimental apparatus consists of two meas
uring chambers of different capacities, and :
a working cylinder having a weighted pis-.1
ton. In order to prevent condensation or
loss of heat high temperature is maintained
in each of the chambers.
RESULTS OF SOME EXPERIMENTS.
In order to render the experiments COM
parative, steam was first admitted to both of
the measuring chambers at pressure of 60
pounds per square inch. This steam, which
represented 20 volumes, was then admitted
to the working cylinder, and it raised the
piston with load of III pounds to a height 1
peated, when the piston was only raised AZ
inches. The smaller of the two chambers
was then half filled with steam at 60 pounds
pressure, and the larger chamber with
heated air at temperature of 1000 Fahren-
heit, which is about the temperature re-
quired in practice and at atmospheric pres
sure as shown by the respective gauges.
The proportions were 2 of steam and 16 of
heated air, and upon the admission OF the
steam to the air the gauges on both cham |
bers instantly showed a pressure of SO |
pounds per square inch. Upon the mixture
of steam and air being admitted to the cyl |
inder the weighted piston was rapidly
driven up ~ inches, which was as high as
it could reach, and represented the strokb |
of the piston within the cylinder. Upon |
the experiment being repeated the weighted |
piston rose much more rapidly, giving the |
cylinder cover violent blow.
A number of other experiments were |
made with similar results, and as whole |
clearly demonstrated that the 20 volumes of |
steam failed to do the work that 2 vol |
umes of steam combined with 16 volumes of |
heated air did. They further showed that |
the best results were obtained with these |
proportions of the two fluids, and these are |
oh fha rubi ~ ioI1
ploys in practice.
MAKES LITTLE OR NO WASTE.
1t should be observed that in practice the |
air is heated at little or no cost by the |
waste heat which in an ordinary engine es-
capes into the atmosphere.
The principles here involved have been
put into practice by MI. Field in portable
engine, which, however, has several draw.
backs in consequence of the mixing cham
bers having to be superadded to the exist
ing engine works These chambers are
on the top of the engine cylinder,
and there is chamber for each end of the
cylinder. Each of these chambers in turn
receives its charge of heated air, into which
is delivereda proportionate charge of steam.
The mixture is delivered from each cham
ber alternately to the front and the back
end of the cylinder, causing the out-strokes
and the in-strokes of the piston in success
sion. Upon the occasion of our visit
the engine was first run with
steam alone and without a load. 1t
was then run with combined steam
and heated air in about the propor-
tions previously stated. The conditions
under which this run was made were the
same as in the previous run, and the same
were taken. 1t may be men,
toned that thetemperature in the air cham
ber should not be less than 1000 Fair. for
the proper development Of the advantages
OF the system. AS matter of fact the air
during the engine trials was
not higher than 5000, but was generally
much lower, owing to the draughts and to
the inefficient construction of the heating
apparatus.
SUCCESSFULLY TESTED OTHERS.
On comparing the results of the two en-
CINE runs, made respectively with pure
steam and with combined steam and heated
air, it was found that there was an absolute
gain of A per cent in favor of the Field
system as against ordinary steam.
The system as well as the experimental
apparatus, has been Independently tested
by three engineers, namely, Mr.. Collett
Homersham, c. E; Mr.. D. K. Clark, c. E.,
and Mr.. Perry f. Nursey, c. E., each of
whose reports substantiates this economy
and points to still higher results with q
larger engine properly and efficiently fitted
with the necessary adjuncts for working
upon Mr.. Fields principle. This, in fact,
is what is now being done, and in due
course the results will be arrived at and
made known. Should they confirm the re-
suits already attained-and there does not
appear to be any reason why they should
lot-Mr Fields discovery cannot fail to
produce a comnlete revolution in motive