Improvements in Engines Operated by the Explosion of Mixtures of Combustible Vapour or Gas and Air.
Year: 1890

page_text: Date of Application, 8th May, 1890
Complete Specification Left, 5th Nov., 1890-Accepted, 17th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in Engines Operated by the Explosion of Mixtures of
Combustible Vapour or Gas and Air.
HERBERT AKROYD STUART, Bletchley Iron and Tin Plate Works, Bletchley, in the
County of Buckinghamshire, Mechanical Engineer, and CHARLES RICHARD BINNEY,
5 Hackney Road in the County of Middlesex, Consulting Engineer, do hereby declare
the nature of this invention to be as follows:-
This invention relates to improvements in liquid hydrocarbon engines or motors,
in which the combustible mixture is produced by combining hydrocarbon vapour
with atmospheric air in due proportions. But it relates more particularly to the novel
means of vaporising the liquid hydrocarbon within the cylinder or compression
chamber or their equivalents and which is herein-after termed the vaporiser. The
vaporiser is so arranged as to have as small a contact as possible with the cold part
of the cylinder, and to expose a large heating surface to the effects of the
combustion.
The object of this is to heat and maintain the vaporiser at an intenso heat, this is
for the joint purpose of vaporising the liquid hydrocarbon and greatly heating the
explosive mixture before ignition, by which means more perfect combustion is obtained,
and a more crude liquid may be used. The said vaporiser also ignites the mixture
and thus dispenses with the firing valve or tube. We have given the novel means by
which we are able to keep the vaporiser at an intense heat and yet provent the pre-
ignition of the explosive mixture which if produced and drawn into the cylinder in
the ordinary manner would explode on some part of the compression stroke of the
cycle and stop the engine.
One cycle of the engine or motor may be as follows :-
The induction stroke which is the first outward stroke instead of drawing into the
cylinder a mixture of hydrocarbon vapour and air, simply draws in pure atmospheric
air; the compression or first return stroke, compressing this air into the intensely
heated vaporiser, and at the desired part of this compression stroke, the supply of
liquid hydrocarbon is forced, in a spray form, on to the heated vaporiser, which
almost instantly changes it into a gas, it combines with the heated air; automatic
ignition takes place, and propels the piston which forms the working or second outward
stroke. The return stroke of the piston clears the products of combustion from the
cylinder and so on.
In some instances we use what is known as the three cycle type; or by the use of
a compression pump, an explosion may be obtained every revolution. It must be
understood that by the application of this intensely heated vaporiser, heavier hydro-
carbon oils may be used and also a more dilute mixture, whilst there is also an
advantage obtained, when the engine governors are acting, from the expansion"
of the heated air which propels the piston in a similar manner to that in a hot-air
engine.
The vaporiser may be made hollow and faced, if desired, with a refractory
material.
A number of small tubes or webs of metal or other suitable pieces of good conducting
material, are inserted in the vaporiser, and expose a very large heating surface to the
explosion. The said tubes may be arranged like those in a feed-water heater, and in
starting the engine the gases from a lamp or otherwise pass through them and heat
them and the vaporiser to the desired temperature to heat the air, vaporise the liquid
hydrocarbon, and ignite the mixture. We preferably corrugate such a box or
chamber so that it may be thin yet strong enough to stand the explosion. This is to

page_text: facilitate the starting of the engine as it can thus be more quickly heated. After the
engine Las been started for a short time the lamp may be dispensed with, as the heat
of the combustion is sufficient to maintain the vaporiser at the proper temperature.
When we desire to use a very dilute mixture we may ignite it by an electric spark, kept
constantly burning in the vapori-ing chamber. It will be soon that by correctly
timing the supply of liquid hydrocarbon, it is impossible to have pre-ignitions and that
no motion is required to actuate the electric spark if used. It is obvious that the
principle deserited herein is applicable to engines or motors using a combustiblo gas.
In such cases the injection of the gas is timed similarly to the injection of liquid
hydrocarbon.
Datal this 7th day of May 1800.
HERBERT AKROYD STUART.
C. R. BINNEY.
COMPLETE SPECIFICATION.
Improvements in Engines Operated by the Explosion of Mixtures of
Combustible Vapour or Gas and Air.
We, HERBERT AKROYD STUART, of Bletchley Iron and Tin Plate Works, Bletchley,
in the County of Buckingham, Mechanical Engineer, and CHARLES RICHARD BINNEY,
of 5, Hackney Road, in the County of Middlesex, Consulting Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formel to be particulary described and ascertained in and by the following.
statement:-
Our invention chiefly relates to that class of engines frequently termed hydro-
carbon engines which are operated by the explosion of a combustible mixture of
petroleum or other hydroeirion vapour an:1 air, but it also relates to engines
driven by the explosion of other combustible mixtures and usually known as gas
engines.
According to our invention we vapourize the liquid hydrocarbon in a box or
chamber attached to and communicating with the interior of the working cylinder
and, in order to provide this vapourizer with as great an area of heating surfaco
as possible it lns within it a number of small tubes or webs of metal or other
pieces of good conducting material. This vapourizer is maintained at the required
heat for vapourizing liquid hydrocarbon by the heat due to the explosion, it only
being necessary to use an external heating apparatus when first starting the engine.
The heat of the said vapourizer also serves for igniting the explosive mixtures
produced therein, thereby dispensing with the use of a firing valve or tube.
In order to prevent the pre-ignition of the explosive mixture, owing to the high
heat of the vapourizer, we first compress the requisite supply of air for the charge
and then inject the oil into this compressed charge by the use of a pump or the
like, the injection of the oil being correctly timed to correspond with the position
of the piston at the time the explosion is to take place.
In order to be enabled to more or less regulate the temperature of the vapourizer
we advantageously arrange over the same a box or cover which is provided with
openings at the top and bottom, so as to allow a current of air to pass through
the space between the vapourizer and the outer box. A lid or dampur is provided
over the opening in the top of the cover to regulate the quantity of air passing
around the vapourizer.
For controlling the speed of the engine we make use of a governor so arranged
us to operate upon the suction valve of the pump when the engine runs abovo
its normal speed in such a manner that a part of the liquid hydrocarbon drawn
by the pump is forced back into the supply tank, while the remaining part which
is delivered to the engine, being insufficient to form a combustible mixture, servos
to lubricate the power cylinder.

page_text: carried into practice by reference to the accompanying drawings, in which
Figure 1 is a sectional side elevation of an engine, worked by a combustible mixture
of hydrocarbon vapour and air, and constructed according to our invention, the engine
being of what is known as the two cycle type:
Figure 2 is an end elevation of the same:
Figure 3 is a section on the line
of Figure 1:
Figure 4 is a plan of a part of the engine:
Figures 5 and 6 are a side elevation and horizontal section respectively of the device
for spraying the oil into the vapourizer :
Figures 7 and 8 are a plan and vertical section respectively of a modified form of
vapourizer.
Similar reference letters indicate similar parts throughout the drawings.
a is the bed-plate and a' the liquid hydrocarbon tank therein, b the power cylinder,
the piston, the connecting rod, e the crank, the crank-shaft, ga counter shaft
driven from the shaft f by the spur-wheels h, which are so proportioned that the
said shaft y revolves once for every two revolutions of the shaft, is the air-valve
and the exhaust valve, the latter being actuated by a cam j¹ on the shaft g through
the inedium of the lever 12.
k, Figures 1 and 3, is the vapourizer which is attached to the rear end of the
cylinder c, and k¹, k¹ are webs contained therein, or as shewn in Figures 7 and 8,
tubes can be used in the place of webs. This vapourizer communicates with the
cylinder through a passage of less sectional area than that of either the piston or the
vapourizer, so that the contact between the vapourizer proper and the cylinder is as
small as possible. As, however, this construction of vapourizer forms part of the
subject matter of our application for Letters Patent No. 15994, dated October 8 1890,
no claim thereto is made in this Specification. The air-valve i is, as shewn, arranged
at the rear of the vapourizer as it enables the incoming air to be heated before passing
into the cylinder. 1 is the cover or casing of the vapourizer also attached to the rear
end of the cylinder c and preferably lined with a non-conducting material such as
asbestos. is a chimney formed on the cover and having the damper ♬ which is
shewn clearly in plan in Figure 4.
m is the pump which is connected to the tank a' by the pipe m² and by the pipe m²
with the spraying device » arranged in the vapourizer k, the said spraying device
consisting of a nozzle n' having a plate n arranged at an angle at the front of the
sume, so that the oil which is projected in the form of a jet against the said plate is
thereby formed into spray. o is the cam for working the plunger of the pump m
through the medium of a bell-crank o¹ and link o, a spring being provided to
return the bell-crank o¹ quickly when released by the cam o and thereby deliver the
charge of oil quickly to the cylinder. p is a set-screw which serves to attach the
cam o to the shaft g and to allow of its adjustment. p is another set-screw, by
adjusting which, the travel of the plunger of the pump m can be varied so as to vary
the supply of oil to the cylinder, if required.
9 is the governor, the balls r, r of which are revolved round the spindle y' by the
crank shaft through the medium of the pulley, belt, pulley, shaft and
mitre-wheels,. The spindle 7 is caused to move down when the balls ŕ diverge
under centrifugal action and partly open the suction valve s of the pump m and
thereby allow a portion of the charge of oil drawn by the pump to be forced back
thereby into the tank a'. The spindle q' and valves are respectively provided with
springs and which serve to return them to their normal positions.
The operation of the engine is as follows:-that is to say, assuming the parts to be
in the position shewn in Figure 1, and a suitable lamp to have been placed beneath
the vapourizer k so as to heat it to the desired degree. If now the fly-wheel be
turned in the direction of the arrow, the outward stroke of the piston will draw in a
charge of air through the valve i, which charge on the return of the said piston will
be compressed. In the meantime the pump m will have been drawing from the tank a
a charge of oil, and at about the time that the piston commences to make its second

page_text: outward stroke, this oil will be sprayed into the vapourizer and with the compressed
air therein form an explosive mixture which, owing to the heat of the vapourizer, is
ignited, thereby driving the piston forward. On the return of the piston the exhaust
valve is opened and the exhaustion of the products of combustion from the cylinder
takes place and so on as hereinbefore described.
After a short time the lamp used for heating the vapourizer can be dispensed with
as the heat produced by the combustion of the mixture causes the vapourizer to
become highly heated.
Instead of the air being compressed in the power cylinder wo can use a separate
pump for that purpose. thereby obtaining an explosion every revolution, instead of
every alternate revolution.
By the use of our vapourizer heavier hydrocarbon oils may be used than heretoforu
and also a more dilute mixture, whilst there is also an advantage obtained, when the
engine governor is acting, from the expansion of the heated air which propels the
piston in a similar manner to that in a hot-air engine.
Although we have described the vapourizer as applied to an engine operated by
the explosion of a combustible mixture of hydrocarbon vapour and air it is to ho
understood that it can also be used in what is known as a gas engine, and in this case
it serves only for igniting the charge.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what wo
claim is :-
1. In an engine operated by the explosion of hydrocarbon vapour and air, tho
employment of a vapourizer in direct communication with the working cylinder,
which vapourizer is maintained at the requisite degree of heat by the combustion of
the combustible mixture therein, the said vapourizer also serving to ignite the
combustible charge, substantially as described.
2. In an engine operated by the explosion of a mixture of combustible gas or
vapour and air, forming the said mixture by introducing the combustible gas or
vapour into a charge of air under compression, substantially as described.
3. The combination with a vapourizer of the kind hereinbefore described, of a
cover surrounding the same and provided with upper and lower openings, substantially
as, and for the purpose, set forth.
4. In an engine of the kind herein before described the employment of governing
mechanism adapted to operate upon the suction valve of the oil injecting pump in
such a manner that, when the engine is running above its normal speed, an insufficiunt
supply of oil will be delivered into the vapourizing chamber, substantially as, and for
the purpose, described.
5. The manufacture and use of the improved hydrocarbon engine hereinbuforo
doscribed and illustrated in the accompanying drawings.
Hated the 5th day of
Avombon 1 ROMA
Boted the 5th day of
ovons box
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.