Improvements in Gas, Petroleum, and like Engines.
Year: 1891

page_text: Date of Application, 16th Jan., 1891
Complete Specification Left, 16th Oct., 1891-Accepted, 21st Nov., 1891
PROVISIONAL SPECIFICATION.
Improvements in Gas, Petroleum, and like Engines.
I, PATRICK FRASER MACCALLUM of Fairbank Helensburgh in the County of
Dumbarton, Consulting Engineer, do hereby declare the nature of this invention to
be as follows:-
This invention relates to a caloric or heat engine having a fluid piston and as
constructed under the invention the engine consists essentially of a vessel preferably
cylindrical in section, placed vertically or nearly so and which constitutes the
combustion or expansion chamber. This vessel is connected with another vessel or
cylinder, which may be merely a continuation downwards in a straight line of the
combustion chamber or it may be placed vertically alongside the combustion
cylinder or at right angles to it, or in any other desired position and connected
thereto by an elbow or bend pipe.
The second vessel which is the working cylinder is provided with a close fitting
piston from which power is transmitted in the usual way when the engine is in
motion.
The space in front of or behind or above the close fitting piston is filled with
water oil or other fluid rising to the required height in the combustion cylinder.
The fuel to be consumed and which may be gaseous liquid or solid in a finely
divided state with the required quantity of air is introduced into the combustion
chamber above the fluid and ignited and its combustion and consequent expansion
forces down the fluid, which in turn imparts motion to the close fitting piston in the
working cylinder. The upward stroke of the fluid piston is or may be effected.
either by the action of a fly wheel or equivalent contrivance or where the engine
has two combustion cylinders the upward stroke of the fluid piston in one may be
effected by the down stroke of the other fluid piston in the other.
The interior of the combustion cylinder is at each stroke wetted by the liquid
forming the fluid piston with the result that unless the liquid be rapidly circulated
it would quickly be heated to the point of vaporisation and so interfere with the
proper combustion of the fuel burnt above the fluid piston.
To prevent this as far as possible a body of some depth is floated on the surface
of the liquid said body being somewhat smaller in diameter than the cylinder.
This body which may be called a float piston may be solid or hollow and composed
of metal or other suitable substance. Preferably the portion immersed in the fluid
should be metallic and the upper portion of non-conducting material. The float
piston may either float freely by displacement in the liquid merely prevented by
guides from coming in contact with the sides of the cylinder or it may be provided
with a piston rod carried downwards through a stuffing box in the bottom of the
bend or elbow pipe making the connection between the combustion and working
cylinders. If necessary the float piston and piston rod may be balanced so that
the float piston may be kept at any desired depth in the fluid piston. Furthermore
to ensure absolute synchroniety of movement between the float and working pistons
the float piston rod may be connected with the working piston rod or other part of
the moving mechanism. In motors with the working cylinders directly below the
combustion cylinders the float piston may be attached directly to the working piston
with a suitable distance between them for the cooling fluid.
In order to allow of the maintenance of a high temperature in the combustion
cylinder the height of the float piston above the fluid piston should be greater than
the length of the working stroke so that the fluid and lower sides of the float piston
never come into contact with any highly heated portions of the cylinder walls.
This practically interposes a deep ring of comparatively cool gases between the

page_text: hot part of the combustion cylinder and the fluid piston. To furthermore ensure
this the air required for combustion (or where gaseous fuel is employed the gas and
the air) may be taken upwards through the float piston rod, and allowed to enter
the combustion cylinder through orifices in the sides of the float piston immediately
above the fluid piston surface, these orifices being made to close automatically
against back passage of air or gas.
By these means a moderate circulation of the fluid is sufficient to prevent
vaporisation of the fluid piston and at the same time allow a very high temperature
in the combustion cylinder. To economise heat the upper parts of the combustion
cylinder may be lined with refractory material and the use of an external water
jacket dispensed with.
The motor constructed as hereinbefore described may be worked according to
any of the well known gas and liquid fuel engine cycles with similar valves and
means for introduction and ignition of the air and fuel and for the expulsion. of the
waste gases.
When liquid or solid fuel is used it is preferred to first fill the cylinder with the
required quantity of air compress it and then introduce the fuel. After combustion
the waste gases may be expelled by an idle stroke or they may be merely permitted
to escape through exhaust valves-preferably placed at the top of the cylinder
while a fresh charge of cold air enters from below. This air may either be under
pressure to assist in forcing out the waste gases or it may be at normal pressure the
waste gases being drawn out by any suitable means of exhaustion.
The fuel may be advantageously introduced at the top of the combustion cylinder
through a pipe or retort internally lined with refractory material and which
attaining a considerable temperature after the motor has been in operation for a
short time effects the gasification and ignition of the fuel in a simple and convenient
manner. Where no auxiliary means of ignition are provided this retort must be
internally heated before starting the motor.
Dated this Fifteenth day of January 1891.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in Gas, Petroleum, and like Engines.
I, PATRICK FRASER MACCALLUM of Fairbank, Helensburgh, in the County
of Dumbarton, Consulting Engineer, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :—
This invention relates to a caloric or heat engine having a fluid or partially
fluid piston and as constructed under the invention the engine consists essentially
of a vessel preferably cylindrical in section placed vertically or nearly so and
which constitutes the combustion or expansion chamber. This vessel is connected
with another vessel or cylinder, which may be merely a continuation downwards in
a straight line of the combustion chamber, or it may be placed vertically alongside
the combustion cylinder, or at right angles to it, or in any other desired position,
and connected thereto by an elbow or bend pipe.
The second vessel, which is the working cylinder, is provided with a close-fitting
piston from which power is transmitted in the usual way when the engine is in
motion. The space in front of, or behind, or above the close fitting piston is filled
with water, oil, or other fluid rising to the required height.
The fuel to be consumed and which may be gaseous, liquid, or solid in a finely
divided state with the required quantity of air is introduced into the combustion
chamber above the fluid and ignited and its combustion and consequent expansion
forces down the fluid which in turn imparts motion to the close fitting piston in the

page_text: working cylinder. The upward stroke of the fluid piston is or may be effected by
the action of a fly wheel or equivalent contrivance or where the engine has two
combustion cylinders the upward stroke of the fluid piston in one may be effected
by the down stroke of the fluid piston in the other.
The interior of the combustion cylinder or of the pipe connecting it with the
working cylinder is according to this arrangement at each stroke wetted by the
liquid forming the fluid piston and unless the liquid is rapidly circulated it would
quickly be heated to the point of vaporisation and so interfere with the proper
combustion of the fuel burnt above the fluid piston, and also abstract a large
quantity of heat.
To prevent this as far as possible a body of some depth is floated on the surface
of the liquid, said body being somewhat smaller in diameter than the cylinder, or
connecting pipe.
This body which may be called a float piston, may be solid or hollow and com-
posed of metal or other suitable substance. Preferably, the portion immersed in
the fluid is metallic and the upper portion of non-conducting material.
The float piston may either float freely by displacement in the liquid merely
prevented by guides from coming in contact with the sides of the cylinder or it
may be provided with a piston rod carried downwards through a stuffing box in
the bottom of the bend or elbow pipe making the connection between the com-
bustion and working cylinders. If necessary, the float piston and piston rod may
be balanced so that the float piston may be kept at any desired depth in the fluid
piston. Furthermore, to ensure absolute synchroniety of movement between the
float and working pistons, the float piston rod may be connected with the working
piston rod or other part of the moving mechanism.
In motors with the working cylinders directly below the combustion cylinders,
the float piston may be attached directly to the working piston with a suitable
distance between them for the cooling fluid, or it may be made in one with the
working piston, the cooling fluid merely surrounding it.
In order to allow of the maintenance of a high temperature in the combustion
cylinder the height of the float piston above the fluid piston should be greater
than the length of the working stroke, so that the fluid and lower sides of the float
piston never come into contact with any highly heated portions of the cylinder
walls, but a deep ring of comparatively cool gases or air is practically interposed
between the hot part of the combustion cylinder and the fluid piston. To further-
more ensure this, the air required for combustion (or where gaseous fuel is
employed, the gas and the air) may be taken upwards through the float piston rod
and allowed to enter the combustion cylinder through orifices in the sides of the
float piston immediately above the surface of the liquid piston, these orifices being
made to close automatically against back passage of air or gas but in any case the
air for combustion whether passed through the float piston or not, should enter the
cylinder or connecting pipe at the lowest practicable point.
By these means a moderate circulation of the fluid is sufficient to prevent vapori-
sation of the liquid piston, and at the same time allow a very high temperature in
the combustion cylinder. To economise heat the upper parts of the combustion
cylinder may be lined with refractory material, and the use of an external water
jacket dispensed with.
The motor constructed as hereinbefore described may be worked according to
any of the well known gas and liquid fuel engine cycles with similar valves and
means for introduction and ignition of the air and fuel, and for the expulsion of the
waste gases.
When liquid or solid fuel is used, it is preferred to first fill the cylinder with
the required quantity of air compress it and then introduce the fuel. After com-
bustion, the waste gases may be expelled by an idle stroke or they may be merely
permitted to escape through exhaust valves, preferably placed at the top of the
cylinder, while a fresh charge of cold air enters from below.

page_text: This air may either be under pressure to assist in forcing out the waste gases, or
it may be at normal pressure, the waste gases being drawn out by any suitable
means of exhaustion.
The fuel may be advantageously introduced at the top of the combustion
cylinder through a pipe or retort internally lined with refractory material, and
which attaining a considerable temperature after the motor has been in operation
for a short time, effects the gasification and ignition of the fuel in a
simple and
convenient manner. This retort must be internally heated before starting the
motor.
On the accompanying drawings Figure 1 is an elevation of the cylinder of a
vertical engine for burning oil and constructed and arranged in accordance with
my invention. A is the combustion cylinder and B the working cylinder with its
lower end arranged as an air pump. is the working piston and D' the hollow float
piston rigidly secured to the working piston by a distance piece E. F is an injector
for the liquid fuel which injector may be water jacketted to prevent premature
vaporisation of the oil. G is a tube or retort for gasifying and igniting the liquid'
fuel and H is a door for the insertion of a gas or oil burner for heating up tlie
retort previous to starting the engine. The combustion cylinder A and the retort G
are lined with refractory material supported by an inner metal casing and the
top of the float piston D has also a refractory covering. J is a short water
jacket which may be placed between the hot combustion cylinder and the cool
working cylinder. K is a valve through which air passes from the lower end'
of the working cylinder to a receiver, (not shewn on the drawings) and L is a valve
for the admission of cold air to the cylinder. M is a projecting ring surrounding
the float piston and closely approaching the sides of the working cylinder so as to
cause the cold air in its ascent to pass uniformly all round the surface of the float
piston. N and N' are pipes for circulating the cooling liquid of the piston. The
valve Kacts automatically, and the valves L and I and also the oil injector
pump O may be operated from the reciprocating or rotative external parts of the
motor as practised in petroleum and gas engines generally. It will be seen from
the foregoing that the fluid piston practically consists of a body of liquid of some
depth resting upon the working piston and of a deeper layer of air or gas
contained in the annular space between the float piston and the cylinder walls.
This form of motor may be worked according to several different cycles, but I
prefer the following working cycle. The retort G being sufficiently heated a
charge of air is forced or drawn into the combustion cylinder through the valve L
and compressed by the up stroke of the piston. The requisite quantity of liquid
fuel is injected into the retort or upper part of the cylinder and this is at once
gasified and ignited by the heat of the retort. All the gases in the cylinder expand
and force down the piston, the comparatively cool air which has been forced into
the annular space round the float piston, at the point of greatest pressure, gradually
rising as the pressure falls, and ensuring complete combustion of the fuel. When
the piston has almost accomplished its down stroke, the exhaust valve I is opened'
and immediately afterwards, the cold air valve L, and the hot waste gases escape, and
a fresh charge of cold air again fills the combustion cylinder. The valves I
and L are closed, compression of the enclosed air takes place, a fresh charge of
fuel is injected and another down stroke accomplished. During working the com-
bustion cylinder lining becomes highly heated, especially at the top, the temperature
gradually reducing towards the point of junction with the working cylinder, and
the refractory covering on the float piston also becomes considerably heated. The
air during compression takes up heat, which re-appears as work on the down stroke,
and also assists the gasification and perfect combustion of the fuel.
When the float piston D is moving up and down in the combustion cylinder its
sides are exposed to a considerable amount of heat, and arrangements may be
made for circulating water or oil round its sides interiorly, but the cooling action
of the air passed upwards round the sides of the float piston at each stroke together

page_text: with the heat abstracted by the liquid of the piston will in most cases render any
special arrangements for interior refrigeration unnecessary.
To adapt the form of cylinder and piston shewn in Figure 1, for burning
powdered fuel, all that is required is the substitution of a suitable fuel feeder for
the oil injector F, the ash of the fuel being swept out by the exhaust gases.
Fig. shews a working cylinder fitted with a trunk piston, the float piston
forming the upper portion of same.
The water or oil circulating pipes N, N' may in this case be conveniently carried
through the sides of the piston, and the working cylinder may be completely water
jacketed, as shewn, which reduces the necessity for rapid circulation of the liquid
part d of the piston.
↓
Fig. 3 shews part of a motor for burning powdered fuel, with the working
cylinder B placed alongside the combustion cylinder and connected thereto by a
bend pipe P, at the lowest point of which is a sludge trap R to catch any ash or
dust which may fall down past the float piston D. The float piston may either
float freely by displacement in the liquid in the pipe P, or it may be provided
with a piston rod or rods S passing through stuffing glands; as shown by the dotted
lines. By means of this rod part of the weight of the float piston may be
balanced, or connected by means of side levers or other mechanism with the
working piston C.
The air valve L and the exhaust valve I are shown of the slide type. T is the
feeder for the solid fuel operated from the external moving mechanism of the
motor. H is a door for the insertion of a gas or oil burner or other means for
heating the upper part of the cylinder before starting the engine.
Fig. 4 shews a means of feeding or injecting powdered fuel, though this may be
accomplished in many other ways. The chamber U in the slide block V is
alternately moved under the powdered fuel hopper W, when a charge of fuel falls
into the chamber U and over the inlet to the combustion cylinder, when the fuel
descends.
To expedite the downward movement of the fuel, a small tube X automatically
uncovered by the movement of the slide V and connecting with a reservoir of
highly compressed air or oxygen may be used.
Figure 5 shews a combustion cylinder A surrounded by a vessel Y in which
water or other liquid may be heated. The retort or chimney G is lined with
refractory material, and the exhaust valve I is placed above the retort, whilst
the fuel injector F is passed through the side. The float piston D, surrounded
by the cooling liquid d, attached directly to the working piston C is shewn at
about the highest point of its stroke.
Fig. 6 shews a method of preventing the access of dust or ash to the working
piston.
The float piston is surrounded by a ring or fin Z which almost fills the working
cylinder and the circulating liquid is forced either continuously or intermittently
through the working piston, for instance by way of a hollow piston rod c as shewn
on the drawing.
The result is that an upward current is maintained in the small annular space
surrounding the fin Z, which sweeps back any particles of dust or grit that may
have passed down the sides of the float piston, the said particles being removed
by the outgoing circulating water. Figure 7 Sheet 2 shews an arrangement of
trunk piston for preventing injury to the close fitting parts from grit or dust. An
annular recess fis formed in the trunk piston and above this recess the diameter of
the piston is slightly reduced, so as to make a communication with another
annular recess y formed at or near the bottom of the float piston. The cooling
liquid enters the recess through the pipe N and passes upward round the
reduced part of the piston into the recess g from which it is removed by the
pipe N. Dust is thus prevented from reaching the close fitting part of the
piston and swept into the recess or pocket g and out of the motor by the pipe N'.

page_text: Having now particularly described and ascertained the nature of the said 'inven-
tion and in what manner the same is to be performed I declare that what I
claim is:-
-
1. In a heat engine or caloric motor operated by the combustion of crude or
unwashed gaseous fuel or liquid fuel or solid fuel in a powdered state the employ-
ment of a fluid piston practically consisting of a depth of water or other liquid
with a superimposed layer of air or gases protected from the commotion of the
gases in the combustion cylinder by a float piston D as described with reference
to Figures 1, 2, 3, 5, 6 and 7 of the annexed drawings.
2. In a heat engine or caloric motor actuated by the combustion of powdered
fuel, the method of injecting the fuel into compressed air contained in a hot
cylinder, or into a hot chamber attached to the cylinder to accomplish the gasifica-
tion and ignition of the fuel substantially as described.
3. In a heat engine or caloric motor the methods of preventing access of dust
or grit to the working pistons by means of continuous or intermittent currents of
water or other liquid substantially as described with reference to Figures 6 and 7
of the accompanying drawings.
Dated this Fifteenth day of October 1891.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.