IMPROVEMENTS IN PETROLEUM MOTORS
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the
Commissioners of Patents on the 8th November 1883. A communication
from Julius Söhnlein, a person resident at Schierstein, in the empire of
Germany
FRANK WIRTH of the firm of Wirth and Company Patent Solicitors, at Frankfort
on the Main, in the Empire of Germany, "IMPROVEMENTS IN PETROLEUM
MOTORS." [A communication from Julius Söhnlein, a person resident at
Schierstein, in the empire of Germany]
This Invention relates to a petroleum engine wherein finely divided petroleum
in the form of a conically diverging spray like jet is injected into a chamber filled
with compressed air and is fired electrically at the point of its greatest density and
during the time of its formation. The expansion resulting from the combustion is
utilised for mechanical work and the regulation of this and the combustion may
take place either in the cylinder or in a separate chamber whence the gases under
pressure pass to the cylinder.
I will describe the former method first. At the outer end of the cylinder there
is an explosion chamber of conical form communicating by its larger end with tho
working space of the cylinder of which said chamber forms a continuation. The
cylinder is cooled by a jacket but the explosion chamber is surrounded by a
petroleum and air reservoir which is in communication with a valve chamber
beyond the end of the explosion chamber. A rotary disc valve turns within the
valve chamber on an axis which passes through the end of the explosion chamber
and terminates just within the smaller end of the said chamber in a notched disc
against which presses a spring the disc and spring being respectively in electrical
connection with the two poles of a dynamo machine
The valve is revolved by gearing from the main shaft and makes one revolution
to four of the said shaft. The valve is provided with two through ports or charge
chambers filled with wire gauge and set diametrically opposite one another which
chambers as the valve revolves in the petroleum at the lower part of the valve
chamber become filled or saturated with a sufficient quantity for an explosive
charge. The valve is also provided with two air ports which are diametrically
opposite one another but at a different radius to the charge chambers. The valve
is also provided with a concentric cavity of small radius for a purpose .heroafter
mentioned
'

page_text: The seat or face against which the valve works has a port to which the charge
chambers in the valve come opposite by the rotation of the valve said port leading
to a tubular nozzle which projects within the explosion chamber in such position
as to direct the jet close to the edge of the electric circuit breaking disc at or near
the point of contact of the spring the nozzle being fitted to slide in its socket in
the end of the explosion chamber and act as a valve for the purpose herenfter
mentioned. Thero is also a through port in the end of the chamber which by the
rotation of the valve alternately communicates with one of the through air ports
and the central cavity above mentioned the latter at same time communicating
with another port connected by an air inlet pipe with an air supply chamber in
the bed of the engine opening to the external air by a small orifice, and commu-
nicating with the opposite end of the cylinder to that at which the explosion
chamber is situated.
The walls of the conical explosion chamber have inwardly projecting, conical or
trumpet shaped gills or deflectors having their smaller ends directed towards the
jet nozzle and co axial therewith. These gills or deflectors are perforated and aro
so shaped and situated that whilst leaving a through passage axially for the central
portion of the jet, they deflect the outer portions of the jet towards the walls of
the explosion chamber and produce a whirling motion which is favorable to rapid
combustion at the same time that by becoming heated during the working they
operate as regenerators and evaporate the outer portions of the jet. By this means
and by the petroleum reservoir surrounding the explosion chamber the waste heat
of the combustion is utilized.
The operation of the engine is as follows. On the forward stroke of the piston
air is drawn into the explosion chamber from the air supply chamber and on the
return or backward stroko the valve cuts off and remains closed until the air
behind the piston in the explosion chamber is compressed to about three
atmospheres. The valve then opens to the valve chamber behind the valve and
remains open until the end of the stroke the compressed air thus passing out of
the cylinder into the valve chamber. On the next forward stroke the valve cuts
off the compressed air port and a charge chamber of the valve filled with petroleuin
comes opposite the port leading to the jet nozzle whereupon the compressed air
behind the valve drives the petroleum out of the charge chamber through the jet
nozzle whence it issues in the form of a divergent jet or spray which moistens the
circuit breaking disc. At the same time the circuit is broken by the contact spring
falling into a notch of said disc causing an electric spark which in passing over to
the pole moistened with petroleum partially evaporates and fires the latter thereby
causing a slight local explosion which determines the total explosion of the jet.
The explosion forces the jet nozzle backwards in its socket causing it to cut off the
communication with the valve chamber and the expansion of the gases does the
work in the cylinder. On the next return stoke of the piston the contents of the
cylinder with the exception of the residue in the explosion chamber are discharged
through the central cavity of the valve and the exhaust ports.
The sooner the jet is fired after its formation, the less will be the charge
consumed and the lower the resulting temperature and pressure, and upon this fact
is based the following mode of governing the engine. The electrical contact spring
is fixed in an insulated plug capable of sliding in a socket and moved in or out by
the ball governor whereby the position of the contact spring relatively to the
notched disc is varied according to the speed of the engine thus causing the jet to
be fired at an earlier or later period after its formation, and consequently varying
the charge exploded. A constant level of petroleum in the valve chamber is
maintained by means of a reservoir above the valve chamber and communicating
therewith by a small orifice at the bottom provided with a cock through which
petroleum may flow in small quantities slightly in excess of the rate of
consumption, and also by a return pipe which dips down to the intended level'in
the valve chamber and rises within the reservoir to a point above the level of the
petroleum therein. Thus the level in the valve chamber rises until the lower end

page_text: of the said pipe is immersed and when upon each second return stroke of the piston
a fresh quantity of air is forced into the valve chamber the unbalanced pressure
therein forces the excess of petroleum back through the pipe to the reservoir.
As the air inlet pipe to the explosion chamber and the front end of the cylinder
both communicate with an enclosed air supply chamber any vapours that might
leak past the piston are received in said chamber whence they are again drawn into
the explosion chamber and burnt. This enclosed air chamber also has the effect of
lessening the noise.
The second mode of carrying out the principle of this Invention, by the
employment of a separate explosion chamber is as follows. The construction of
this particular engine is substantially the same as that of a single cylinder air
compressor for working by steam with this difference that in this case the
compressed air discharges into the valve chest which again communicates with the
explosion chamber. The valve is a reciprocating slide having the usual lap. At
the front side of the piston the engine acts as an air pump and at the other side it
receives the expansive pressure of the gases
The explosion chamber is pear shaped and has double walls the space between
which at the lower part contains petroleum said chamber being provided internally
with conical deflectors or gills the construction being substantially the same as
before described the chamber being however vertical with its smaller end upwards
and is surmounted by a valve and charge chamber with which is combined a jet
nozzle and electric circuit breaker. The valve is a conical lifting valve and its rod
passes through the charge chamber and is connected loosely with the sliding jet
nozzle. Between the valve and the passages leading to the jet nozzle is a charge
chamber filled with wire guage.
The nozzle itself carries one contact piece the other being supported in a suitable
position opposite the orifice of the nozzle to enable the first one to make contact
there with when the nozzle is in its lowest position at which time it is in commu-
nication with the chamber containing the charge of petroleum. The operation is
as follows. The piston in its forward stroke pumps air into the valve chest and
the explosion chamber which communicates therewith. At the other end of the
cylinder the air is compressed by reason of the lap at one end of the slide valve
the compressed air passing by a pipe into the upper part of the space forming &
petroleum reservoir between the double walls of the explosion chamber. There is
consequently a higher pressure in the petroleum reservoir than in the explosion
chamber which continues during the return stroke of the piston. At the
beginning of the piston stroke the valve above the charge chamber is opened by
the main shaft whereupon petroleum is forced from the reservoir through a pipe
into the valve chamber, past the valve into the charge chamber at the same time
that compressed air also enters through another pipe from the upper part of the
petroleum reservoir, and the air and petroleum together pass from the charge
chamber through suitable passages to the jet nozzle whence it issues into the
explosion chamber past the electrical contact pieces which it moistens as before.
After the valve has opened a certain distance as above described it raises the jet
nozzle thus breaking electrical contact and causing a spark which determines the
explosion of the jet whereupon the nozzle is forced upwards still farther and the
jet cut off. At this moment the engine piston is at the beginning of its stroke, the
slide valve commences to open the pressure generated in the explosion chamber is
admitted to the cylinder and acting on the piston drives it forward at same time
that a fresh quantity of air is forced out of the other end of the cylinder into the
explosion chamber and the action recommences as above described.
The performance of the engine depends as before on the duration of the jet
which is regulated by the time of firing which is in turn dependent on the rate at
which the petroleum and air valve is lifted. The valve motion may be of any
known kind used for steam engines and may be controlled by a governor and needs
no further description.

page_text: Instead of petroleum being employed for working the engine any other -hydro
carbon,or.a mixture of different hydro carbons may be taken, whether derived from
organic or mineral sources or more or less volatile than petroleum provided that it
..or they be capable of fine division mechanically and perfectly combustible.
Instead of producing the excess pressure used for forcing in the jot in the case of 5
the two methods of application herein described, by the means set forth, a second
smaller cylinder may be,employed which directly operates the forcing in of the jet,
or in the former arrangement the engine may in a manner easily contrived be
caused to act in front of the piston for the purpose of producing the excess
pressure. Similarly instead of the particular engine described under the second 1
arrangement a rotary motor may be employed which either arranged singly
alternately compresses air and works like the first arrangement. or arranged in
duplicate the one giving power and the other delivering compressed air for the
petroleum reservoir.
The following special characteristics of the engine may be shortly noticed.
1st. Dispensing with the preliminary heating and dispensing with the use of any
auxiliary substances for the first starting which is rendered practicable by the use
of a petroleum jet, and the peculiar method of firing the same at the point of its
greatest density and within the time of its formation
1
2nd. The production of a perfect residuum free combustion of the vapour from 2
the petroleum supplied in a cold state, in such manner that the combustion of the
spray like jet takes place under an excess of oxygen.
3rd. The greatest possible useful effect which is obtained by the combustion of
the spray like jet in compressed air, the application of less dense, finely divided
spray jets, the heating of the jet within the cylinder by means of a regenerator, the 2
utilisation of the excess heat of the combustion space, the method of regulating and
the simplification of the valve mechanism.
4th. The perfectly certain electric firing effected by the contacts, moistened with
petroleum.
5th. The independence of the firing with respect to the quantity of the gases 3
which in addition to the air mingled with the jet are present in the combustion
chamber, such independence being attained by firing the jet within the time it.is
still suspended as a whole in the combustion chamber.
"
6th. The proportion in the explosive mixture of the difficulty volatilising to the
readily volatilising petroleum hydro carbons is caused to be the same in all the 3
charges, by reason of the natural mechanical distribution of the fluid, petroleum,
7th. The prevention of the disagreeable smell of petroleum by means of a
petroleum tight closure separating the engine container from the space in which
the engine works which closure is rendered practicable by the method of firing.