IMPROVEMENTS IN HOT-AIR AND CALORIC ENGINES.
Year: 1883

page_text: LETTERS PATENT to Edward Field of,Chandos Chambers, Adelphi, in the
City of Westminster, Consulting Engineer, and Harrison Aydon of Whitton,
near Hounslow, in the County of Middlesex Civil Engineer for an Invention
of IMPROVEMENTS IN HOT-AIR AND CALORIC ENGINES.
1
PROVISIONAL SPECIFICATION left by the said Edward Field and Harrison
Aydon at the Office of the Commissioners of Patents on the 19th July. 1883.
EDWARD FIELD, of Chandos Chambers, Adelphi, in the City of Westminster,
Consulting Engineer, and HARRISON AYDON, of Whitton, near Hounslow, in the
County of Middlesex, Civil Engineer, "IMPROVEMENTS IN HOT AIR AND CALORIC
ENGINES
33
According to our invention in hot air and coloric engines in order to increase
their efficiency we provide for the injection of a small quantity of water to mix
with the hot gases as steam thereby largely increasing the expansive force of such
gases.
In one arrangement as applied to a hot air engine we provide in the generator
a plate or tray on to which water is projected so that it may flash into steam and
mix with the hot gases.
In another arrangement as applied to a caloric engine such as that well known
as Rider's, we provide apparatus for forcing a regulated quantity of water at each
revolution to mix as steam with the hot air in the working cylinder. Such water
is subsequently condensed or cooled with the air and used again.

page_text: •
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Edward Field and Harrison Aydon in the Patent Office on the
19th January 1884.
EDWARD FIELD, of Chandos Chambers, Adelphi, in the City of Westminster,
Consulting Engineer, and HARRISON. AYDON of Whitton, near Hounslow, in the
County of Middlesex, Civil Engineer IMPROVEMENTS IN HOT AIR AND CALORIC
ENGINES."
"
According to our invention in hot air and caloric engines, in order to increase
their efficiency, we provide for the injection of a small quantity of water to mix
with the hot gases, as steam, thereby largely increasing the expansive force of such
gases.
In one arrangement, as applied to a hot air engine, we provide in the generator
a plate or tray on to or towards which water is projected so that it may flash into
steam and mix with the hot gases.
In another arrangement, as applied to a caloric engine such as that well known
as Rider's we provide apparatus for forcing a regulated quantity of water, at or
just before the commencement of each revolution or effective stroke to mix as
steam with the hot air and act with it on the piston or plunger of the working
cylinder. Such water is subsequently condensed or cooled with the air, and used
again.
Referring to the drawings, Fig 1 represents in vertical section the retort or
generator of a hot air engine having our invention applied to it. By hot air
engine we mean an engine wherein the gases evolved as products of combustion
from fuel in a retort or generator are employed in a cylinder or cylinders as motive
fluid acting on a piston or pistons.
a is the interior of the retort or generator which may be of any suitable well
known construction. b is a tray in the upper part of the retort or generator,
and c is an orifice through which water is periodically forced and allowed to
descend in small regulated quantities to vaporize and mix as steam with and
expand the gases just prior to their passing on to do duty in the cylinder or
cylinders. Water not vaporized before reaching the tray b. will be prevented by
it from descending to the fuel. d is a pipe forming a continuation of the fuel
feeding hopper: A pump, not shewn, and which may be of any suitable descrip-
tion, forces water intermittently by the pipe f into the retort or generator; the
quantity being regulated by a cock e controlled by the governor of the engine..
Just before the commencement of each effective stroke of the engine, the pump
makes a stroke; and thereby forces a small quantity of water by the pipe f to the
retort or generator. The pump is to be provided with an overflow or a loaded
escape valve so that when the delivery is shut off by the governor the pump may
nevertheless go on working, or in lieu of using an intermittent pump there may
be a constant pressure of water, an intermittent cock or valve. being employed, as
will be presently described with reference to the caloric engine, to open and close
communication with the retort or generator, shortly before the commencement of
each effective stroke of the engine. The quantity of water admitted when. this
cock or valve is open will be regulated by the governor and cock e already described
and shewn. The water is introduced to the retort or generator just previous to
opening of the communication between the retort or generator and the working
cylinder, and a good result may be obtained by then introducing such a quantity
of water as will form a volume of steam having the same pressure as the gases in
the retort or generator, and equal to from 12. to 20% of the volume of products of

page_text: combustion produced during each effective stroke of the piston. For example, let
the volume of gases produced during each effective stroke of the piston be 200
cubic inches, at 60 lbs pressure per square inch, then a good result may be obtained
by injecting into the retort or generator, before the commencement of each effective
stroke of the engine piston, such a quantity of water as will produce say 40 cubic
inches of steam at that pressure. The water may be heated, or even converted
into steam, before entering the retort or generator. Heat remaining in the gaseous
products that have done duty in the working cylinder of the engine may be
employed, by waste heat utilizing means such as are well known to Engineers, for
raising the temperature of the water before its introduction into the retort
or generator. The dome of the retort or generator may be lined with refractory
material as shewn by dotted lines in Fig. 1.
Figs 2 to 5 illustrate our invention as applied to what we call a caloric engine,
by which we mean that class of engine to which what is known as Rider's hot air
engine belongs, and wherein the air is used over and over again, the same air being
alternately heated and cooled. Fig 2 is a side elevation shewing part of the engine
with means for forcing water intermittently into the passage communicating with
the hot pot in which air is heated and expanded to act upon the piston or plunger
that works in the chamber or cylinder above the hot pot. In this figure is also
shewn the sumpt whereby the water of condensation is collected for re-use.
Fig 3 is a view at right angles. to Fig. 2
Fig 4 is a plan
Fig 5 is a section in line A. B. of Fig 2 shewing the intermittent valve arrange-
ment, and its connection with the passage that communicates with the hot-pot.
g, is the working cylinder, with hot pot and furnace below, h. is the displacer
cylinder, whose piston, acting in conjunction with that of the working cylinder,
circulates the air, causing it to alternately occupy the hot air chamber below the
working cylinder, and the displacer chamber below the displacer cylinder as is
usual in engines of the kind in question.- is the intermittent injection valve fitted
with its lever and an adjustable touch screw . is a strong air vessel fitted on
to the top of the body of the valve and in communication with the delivery.
pipe from the pump. m is the outer wall of the vapour passage formed round or
at the lower end of the working cylinder and into which wall the end of the
casing of iis fixed in communication with the air passage. o is a nest of valves
and boxes in communication with the pump, and with the, intermittent valve i,
also with the well or "sumpt" p by means of the suction pipe p; the positions of
the valves are indicated as follows; o¹ the suction valve, o² the delivery valve, and
03 the spring loaded relief valve, which discharges the water passing through it
back again into the sumpt p by means of the pipe p' which acts as a return pipe
when required. is the pipe connecting the nest of valves o with the pump. 8. is.
the pump worked by the engine. t is the lever for giving the touch-motion to the
screw k. This lever t is jointed into, and supported by the bracket and its
longer arm is so positioned as to be moved by the cam or tappet t' on the crank
shaft once during every revolution of the engine thrusting the short arm t² against
the touch screw k. and thereby actuating the valve i once every revolution. ¹ is a
lever actuating valve i, and a spring to close the valve i, when not kept open
by k. A spring not shewn keeps the lever arm t¹ against the cam. The action of
the apparatus is as follows-The touch screw is withdrawn out of reach of .
the arm, t2 and the engine is started as an ordinary Rider (caloric) engine The
pump s then begins to draw water by the pipe p' from the sumpt p and forces it
through the delivery pipe into the air vessel where the maximum pressure
permitted by the relief valve o³ accumulates. The air vessel is always in communi-
cation with the body of valve i and the instant the valve i is opened water rushes
through into the vapour passage m¹. The touch screw is then advanced, so that
the arm t2 just comes in contact with the touch screw k. opening the valve i slightly
but receding from it immediately when it is closed by the spring ², therefore it
will be seen that according as the screw is more or less prominent so will the

page_text: '
quantity of water injected into the vapour passage or chamber be more or less. If
the engine goes too fast the prominence of the screw & must be reduced, if on the
contrary the engine goes too slowly the prominence of must be increased.
Where the amount of work to be done is constantly varying, the touch piece is
regulated by the governor-or the stroke of the lever t may be varied by the same
means.
The water may be introduced in other ways than that explained above such as
by a pump giving strokes at the proper times and having its stroke regulated by a
governor or by hand as the case may be.
The same means of injecting water as described with reference to the Rider
engine may be used in the case of the hot air engine.
Where the construction of the caloric engine is such as to render it possible it
will usually be advantageous to introduce the water according to our invention
into the hot pot instead of into the hot air passage.
Having described the nature of our said invention and the manner of carrying
it into practical effect, we hereby declare that what we consider to be novel and
original and therefore claim as secured to us under the Letters Patent first
hereinabove in part recited is.
1. In an engine of the kind hereinabove referred to as a hot air engine providing
for an intermittent (or periodic) admixture of vaporized water with the gaseous
products in the retort or generator, substantially in the manner described with
reference to Fig 1 of the drawings for the purpose set forth.
•
2. In an engine of the kind herein above referred to as a caloric engine providing
for increased expansion of the hot air by causing vaporized water to mix and do
duty with the said hot air substantially in the manner described with reference to
Figs 2 to 5 of the drawings.
In witness whereof I the said Edward Field have hereunto set my hand and
seal this nineteenth day of January in the year of our Lord one thousand eight
hundred and eighty-four.