IMPROVE- MENTS IN CALORIC ENGINES
Year: 1880

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for an Invention of "IMPROVE-
MENTS IN CALORIC ENGINES." A communication from abroad by Julius
Hock, of Vienna, in the Austrian Empire.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at the
Office of the Commissioners of Patents on the 7th April 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN CALORIC ENGINES." [A communi-
cation from abroad by Julius Hock, of Vienna, in the Austrian Empire.]
This Invention relates to caloric engines wherein air compressed by a pump is
forced through a closed fire box or combustion chamber in order partly to support
the combustion of fuel and partly to pass in a heated condition together with the
gaseous products of combustion into the working cylinder, the piston of which is
propelled thereby. One of the present improvements relates to the cooling of the
air undergoing compression in order to prevent the loss of useful effect that other-
wise results from the increase of temperature due to the compression. For this
purpose the air compressing pump has at its end or ends a small orifice com-
municating by a pipe or channel with a water tank situated at a moderate
height above the air pump, so that the water will flow down by gravity through
the pipe and enter the cylinder through the said orifice. In close contiguity to
such orifice is a second orifice formed obliquely to the first one, and communicating
by a passage or pipe with any convenient part of the combustion chamber or
passages containing the air under pressure, so that a small jet of air will enter the
cylinder through such orifice, and in impinging obliquely upon the small jet of
water entering the pump cylinder will blow this into spray, which in mixing
intimately with the air that is undergoing compression in the pump will take up
heat therefrom. Steam will thus be formed at the same time by the action of the
heat on the water spray, and this steam will pass away together with the air to do
duty in the engine cylinder.
In order to prevent the water from continuing to run into the air compressing
cylinder when the engine is not at work, the supply is automatically stopped by

page_text: providing on the supply pipe a cock or valve acted upon by a weight or spring
tending to close it, and also in the contrary sense, by a piston in a small cylinder
communicating with the passages or chamber for compressed air, so that when on
the starting of the engine a certain air pressure has been attained, this, in acting on
the small piston, will force open the valve or cock and allow the water to enter the
air compressing cylinder. In order to supply a further quantity of steam to mix
with the air and gases under pressure, so as to increase the useful effect of the
engine, one or more jets of water are forced in the form of spray at one or more
points into the chambers or passages containing the heated air and gases under
pressure, such introduction of water being effected in regulated quantities by means
of a pump. The water is by preference forced through a narrow adjustable annular
orifice formed by the insertion into a circular opening-of n-conical-plug at the end
of a rod that can be screwed more or less forward so as to increase or decrease the
annular space between the plug and the opening. One such jet of water spray may
advantageously be introduced into the closed combustion chamber of the engine,
and another in the pipe leading from the fire box to the working cylinder. In the
latter case there are provided in the pipe just below the said jet a number of wire
gauze screens placed one above the other, so that the water spray in falling upon
and passing through such screens, heated to a considerable extent by the gases in
the pipe, will rapidly be converted into steam, and at the same time to be mixed
intimately with the air and gases that are also passing through the screens. As
these gases carry with them a certain amount of dust from the fuel in the fire box,
such dust, as also the solid matter held suspended in the water, will be intercepted
by the screens, which are removed from time to time to clear them of such accu-
mulated deposits. To facilitate such removal the pipe is provided at tho point
where the screens are situated with a side opening closed hermetically by a cover
secured by screws, the screens being merely placed loosely one above the other in
the pipe, which has shoulders or lugs for supporting them.
It will be evident that a certain relation will have to be maintained between tho
quantity of air introduced into the fire box and the quantity of water mixed there-
with for the production of steam. Upon the quantity of air will depend the
quantity of fuel that can be burnt and heat produced, and upon this depends again
the quantity of water that can be converted into steam of definito temperature,
and thus it follows that if the temperature is to be maintained approximately
constant the proportion between air and water supply once determined must also
be constant. This is effected by regulating the pressure in the chambers and
passages containing the air and gases under pressure as follows:-
The speed of the engine is regulated by causing a governor to effect the opening
of the admission lift valves to the working cylinder for a greater or shorter length
of time by means of revolving and sliding cams, which open the valves against the
action of springs. On the load on the engine decreasing the cut off is consequently
caused to take place earlier, the effect of which would be to produce an increase of
pressure in the chambers and passages containing the air under pressure if the
compressing cylinder and water jets continued in full action. To prevent this a
piston in a small cylinder is acted upon in one direction by the air pressure in the
chambers or passages, and in the contrary direction by a weight or spring, which is
so adjusted that as soon as the air pressure exceeds the desired limits the piston is
moved in opposition to the weight or spring, and is thereby made to act on levers
that keep the supply valves of the compressing pump closed, and also on other
levers that close the cocks or valves on the supply pipe of the water jets until the
pressure is again reduced.
The gearing by which tho force pump for the water jets is worked from the
engino is so arranged as to be readily disconnected, so that for starting the engine
the pump lever can be worked by hand in order to forco sufficient water into the
fire box to produce steam of the requisite pressure to move the working piston.
For larger engines, and particularly those that require to be maintained constantly
in action for a considerable length of time, such as marine engines, two or more

page_text: separate fire boxes or combustion chambers are provided, and the air pipes and
passages leading from the compressing pump, as also those leading to the working
cylinder, are made to communicate with both or all the combustion chambers, but
are provided with valves so arranged that the one or the other combustion chamber
can be cut off from the communications for the purpose of cleansing and repair
without interfering with the action of the engine.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Denton Abel in the Great Seal Patent Office on the 6th
October 1880.
CHARLES DENTON ABEL, of No. 28, Southampton Buildings, Chancery Lane, in
the County of Middlesex. "IMPROVEMENTS IN CALORIC ENGINES." A communi-
cation from abroad by Julius Hock, of Vienna, in the Austrian Empire.
This Invention relates to caloric engines wherein air compressed by a pump is
forced through a closed fire box or combustion chamber in order partly to support
the combustion of fuel, and partly to pass in a heated condition together with the
gaseous products of combustion into the working cylinder, the piston of which is
propelled thereby.
One of the present improvements relates to the cooling of the air undergoing
compression, in order to prevent the loss of useful effect that otherwise results from
the increase of temperature due to the compression. For this purpose the air
compressing pump has at its end or ends a small orifice communicating by a pipe
or channel with a water tank situated at a moderate height above the air pump, so
that the water will flow down by gravity through the pipe, and enter the cylinder
through the said orifice. In close contiguity to such orifice is a second orifice
formed obliquely to the first one, and communicating by a passage or pipe with
any convenient part of the "pressure space" (by which term I designate the
combustion chamber, and the passages containing the air or gases under pressure
leading therefrom and extending up to the admission valves of the working
cylinder), so that a small jet of air will enter the cylinder through such orifice, and
in impinging obliquely upon the small jet of water entering the pump cylinder will
blow this into spray, which in mixing intimately with the air that is undergoing
compression in the pump will take up heat therefrom. Steam will thus be formed
at the same time by the action of the heat on the water spray, and this steam will
pass away together with the air to do duty in the engine cylinder.
In order to prevent the water from continuing to run into the air compressing
cylinder when the engine is not at work, the supply is automatically stopped by
providing on the supply pipe a cock or valve acted upon by a weight or spring
tending to close it, and also in the contrary sense, by a piston in a small cylinder
communicating with the " pressure space," so that when on the starting of the

page_text: engine a certain air pressure has been attained, this, in acting on the small piston,
will force open the valve or cock and allow the water to enter the air compressing
cylinder.
In order to supply a farther quantity of steam to mix with the air and gases
under pressure, so as to increase the useful effect of the engine, ono or more jets of
water are forced in the form of spray at one or more points into the "pressure
space," such introduction of water being effected in regulated quantities by means
of a pump. The water is by preference forced through a narrow adjustable
annular orifice formed by the insertion into a circular opening of a conical plug at
the end of a rod that can be screwed more or less forward, so as to increase or
decrease-the-annular space between the plug and the opening.
One such jet of water spray may advantageously be introduced into the closed
combustion chamber of the engine, and another in the pipe leading-from-the.fire
box to the working cylinder. In the latter case there are provided in the pipe just
below the said jet a number of wire gauze screens placed one above the other,
so that the water spray in falling upon and passing through such screens heated
to a considerable extent by the gases in the pipe will rapidly be converted into
steam, and at the same time be mixed intimately with the air and gases that are
also passing through the screens. As these gases carry with them a certain amount
of dust from the fuel in the fire box, such dust as also the solid matter held
suspended in the water will be intercepted by the screens, which are removed
from time to time to clear them of such accumulated deposits. To facilitate
such removal, the pipe is provided at the point where the screens are situated
with a side opening closed hermetically by a cover secured by screws, the screens
being merely placed loosely one above the other in the pipe which has shoulders
or lugs for supporting them.
It will be evident that a certain relation will have to be maintained between the
quantity of air introduced into the fire box, and the quantity of water mixed
therewith for the production of steam. Upon the quantity of air will depend the
quantity of fuel that can be burnt and heat produced, and upon this depends again
the quantity of water that can be converted into steam of definite temperature, and
thus it follows that if the temperature is to be maintained approximately constant,
the proportion between air and water supply once determined must also be
constant. This is effected by regulating the pressure in the pressure space, as
follows:-
The speed of the engine is regulated by causing a governor to effect the opening
of the admission lift valves to the working cylinder for a greater or shorter length
of time by means of revolving and sliding cams, which open the valves against the
action of springs. On the load on the engine decreasing the cut off is consequently
caused to take place earlier, the effect of which would be to produce an increase of
pressure in the chambers and passages containing the air under pressure if the
compressing cylinder and water jets continued in full action. To prevent this a
piston in a small cylinder is acted upon in one direction by the pressure in the
pressure space, and in the contrary direction by a weight or spring, which is so
adjusted that as soon as the air pressure exceeds the desired limits the piston is
moved in opposition to the weight or spring, and is thereby made to act on levers
that keep the supply valves of the compressing pump closed, and also on other
levers that close the cocks or valves on the supply pipe of the water jets until the
pressure is again reduced.
The gearing by which the force pump for the water jets is worked from the
engine is so arranged as to be readily disconnected, so that for starting the engine
the pump lever can be worked by hand in order to force sufficient water into the
fire box to produce steam of the requisite pressure to move the working piston.
For larger engines, and particularly those that require to be maintained
constantly in action for a considerable length of time, such as marine engines, two
or more separate fire boxes or combustion chambers are provided, and the air pipes
and passages leading from the compressing pump, as also those leading to the

page_text: working cylinder, are made to communicate with both or all the combustion
chambers, but are provided with valves so arranged that the one or the other
combustion chamber can be cut off from the communications for the purpose of
cleansing and repair without interfering with the action of the engine.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 shews a side view of a caloric engine to which the before described
improvements are applied; Fig. 2 shews a part longitudinal section of the force
pump A for forcing the air under pressure into the combustion chamber B, of which
a vertical section is shown at Fig. 3. A small jet of water is introduced into the
pump cylinder through a nozzle at a, such jet being divided into fine spray by
means of an air jet b impinging obliquely thereon, and supplied from a passage B
which is in communication with the "pressure-space." The water spray in becoming
intimately mixed with the air in the pump cylinder takes up the greater part of the
heat evolved by the compression of the air, and becomes converted into steam,
which operates together with the heated air in propelling the working piston, and
thus serves to increase the power of the engine, both by increasing the initial
pressure, as also by its greater heat capacity, which is clearly shewn by the more
gradual downward curve of the indicator diagram during tho expansion.
The water jet a is supplied merely by gravity from the reservoir C (Fig. 1)
placed at a somewhat higher level; and in order to cut off the supply automatically
when the pump is not in action, a cock or valve on the supply pipe is arranged in
connection with a piston and weighted lever, as shewn at Fig. 4, where d is the
supply pipe from the reservoir; d, the pipe to the cylinder; e, n casing com-
municating at e¹ with the before-mentioned passage B₁ containing air under
pressure; a valve closing the ingress from the pipe d; g, a piston pressed
upwards by the air in B, aud drawn downwards by the weighted lever h. Thus,
it will be seen, that as soon as, by the stopping of the engine, the air pressure
in B has decreased so as to be overcome by the weighted lever h, the latter will
draw the valve f down on its scat so as to cut off the water supply to the cylinder.
The weight, or an equivalent spring, is so proportioned as to be overcome by the
minimum air pressure at which the engine will begin to work.
Fig. 3 shews at i the application of a water jet to the combustion chamber of
the engine for the purpose of producing an additional quantity of steam to mix
with the compressed heated air, as above described, the water being forced in the
form of spray by means of a small force pump k (Fig. 1) driven by the engine,
so that a definite quantity is supplied at each stroke.
In addition to or in lieu of this water supply another waterjet may be provided
in the air pipe or passage to the cylinder, as shewn at in the vertical section at
Fig. 5. Below the jet are provided in the pipe a number of superposed wire gauze
screens m, which are introduced through a side opening closed by a cover, as shewn
at m¹ in the sectional plan at Fig. 6. The screens servo both to effect the con-
version into steam of the water falling upon them from the jet l, and to cause this
to mix intimately with the hot gases passing through them on their way from
the combustion chamber to the working cylinder, and they furthermore serve to
intercept the dust carried along by the gases from the combustion chamber;
they are taken out from time to time to remove such accumulation of dust.
The power of the engine is regulated by means of revolving cams n (Fig. 1)
acting on levers connected to the admission valves at o, the cams being made to
slide upon their shafts by the action of the governor ? so as to effect the cut off
sooner or later, according as the power of the engine requires to be decreased or
increased. On the cut off taking placo sooner in order to decrease the power of the
engine, the pressure in the combustion chamber and passages would accumulate
unless means were provided for limiting the maximum pressure; and in order to
effect this a small cylinder q, shewn in enlarged longitudinal and transverse section

page_text: respectively at Figs. 7 and 8, has a piston that is pressed outwards by the air
pressure in the combustion chamber against the action of a loaded lever s, the
pressure e of which is adjusted to the maximum air pressure required to be main-
tained. The piston is connected by rods and levers S1, S2, to the valves of the air
pump A, and to the cock or valve t of the water supply, so that on the pressure
increasing beyond the desired maximum, the piston r in being forced back against
the action of the lever will throw the air pump out of action, and close the water
supply to the combustion chamber.
Having thus described the nature of the said Invention, and in what manner the
same is to be performed, as communicated to me by my foreign correspondent,
-I-claim,-
First: The admixture of water spray with the air-or-gases-under pressure in
caloric engines, of the kind herein referred to, for the purpose of cooling the air
and producing steam to operate in combination with such gases, substantially as
and for the purposes herein described.
Second. The arrangement herein described with reference to Figs. 1 and 2 of
the Drawings whereby a jet of water is caused to enter by gravity into the air
compressing cylinder, and is converted into spray by an air jet introduced from the
pressure space of the engine.
Third. Regulating automatically the water supply to caloric engines, such as
referred to in the preceding claims, by causing the gaseous pressure in the pressure-
space to act upon a piston connected to a valve or cock on the supply pipe, and
acted upon in the opposite direction by a weight or spring, substantially as hercin
described.
Fourth. The method of regulating the gaseous pressure in the pressure space by
means of a loaded piston acted upon by such pressure, and connected to the valves
of the air and water supply in such manner that when the gaseous pressure exceeds
the desired maximum, the piston is caused thereby to cut off the air and water
supply, substantially as herein described.
Fifth. The method of producing the requisite pressure for starting a caloric
engine by forcing water into the combustion chamber, substantially as herein
described.
Sixth. The use, for supplying a caloric engine with heated gases under pressure,
of two or more separate combustion chambers, which may either be made to operate
in combination with or independently of each other.
In witness whereof, I, the said Charles Denton Abel, have hereunto set
my hand and seal, this Sixth day of October, in the year of our Lord
One thousand eight hundred and eighty.
CHAS. D. ABEL. (L.S.)