Improvements in or Connected with Petroleum-motors or Engines Worked with Liquid Fuel..
Year: 1886

page_text: Date of Application, 16th Aug., 1886.
Specification Accepted, 3rd May, 1887.
Improvements in or Connected with Petroleum-motors or Engines
Worked with Liquid Fuel..
I, MATHIAS VITAL SCHILTZ, Doctor of Medicine, of Cologne, Germany, 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:-
Experiments with petroleum engines, in which the combustion chamber is strongly
heated, have demonstrated that it is very difficult to employ non-volatile fuel as a
source of power, because the heat required to prevent condensation in the combustion
space can be hardly maintained without injury to the power cylinder.
Experiments have also shown that in a heated chamber a petroleum mist, that is to
say, a gaseous mixture containing un-evaporated or re-condensed petroleum in the
shape of fine spray or drops, will burn from and after it has once been ignited, and
that the combustion then takes place in the hot chamber without residue, if the ignited
mixture contains sufficient oxygen. In such a case the ignition offers the principal
difficulty.
Consequently, in order to ignite and completely consume such a petroleum mist
under the circumstances mentioned above, it is indispensable to heat the combustion
chamber as much as possible and especially that the inflammable mixture should have
a high temperature already before ignition. The mixture must contain, besides
oxygen, a sufficient quantity of gaseous fuel, to be inflammable according to well
known laws without the addition of petroleum mist; the mixture thus consisting of
a weak but still inflammable mixture of gaseous bodies and finely dispersed liquid
fuel.
If such a mixture at a high temperature is ignited at a moderate pressure, it burns
gradually without explosion, because the gaseous fuel near the point of ignition will
first catch fire, the heat thus produced will evaporate or destroy the adjacent particles

page_text: of petroleum mist, the gases or carbonaceous dust generated by this evaporation or
chemical decomposition will burn with oxygen and thus continue the process of slow
combustion until all fuel is completely consumed. Probably the hydrogen of the
whole mixture will be consumed before the carbon, so that the latter sustains the
combustion even after the ignition of hydrogen has proceeded through the whole
space. Strong previous heating of such a combustible mixture is indispensable,
otherwise the heat produced by the combustion of any particle would not be sufficient
for evaporating or destroying adjacent particles and then igniting them.
It has also been found in the case of engines working with heated combustion
chambers that a very slight addition of coal gas is sufficient to render finely divided
heavy illuminating petroleum applicable as a motive power fluid and that crude or
unrefined petroleum, which contains volatile hydrocarbons, is more easily applicable
for motive power, than illuminating petroleum. Consequently heavy hydrocarbons
or non-volatile liquid fuel, such as illuminating petroleum, vegetable fat, tar, even
tallow and paraffin, can be rendered applicable as fuels by the following means:
1. Their mixture with gaseous or volatile fuel.
2. Sufficient previous heating.
3. Evaporation or fine distribution.
4. Mixture of fuel with atmospheric air in such a proportion, that the product
consists of a weak but still inflammable gaseous mixture with the addition of petroleum
mist, and the quantity of air necessary for its combustion. The proportions of fuel
and air may be previously calculated or ascertained by experiment.
The temperature required for the ignition of the inflammable mixture is independent
of the method of ignition. Special means for ignition are described later on.
The four conditions mentioned above are fulfilled by causing the liquid fuel to
trickle in small measured quantities into a heated chamber, to spread over a large
metallic heating surface and exposing it to a strong current of highly heated air; the
fine distribution being assisted by metal shavings.
For this purpose the combustion chamber of the engine is provided with a special
jacket arrangement as shown in Figs. 1 to 5 of the drawings; or a similar arrange-
ment is applied to an ordinary furnace, as shown in Figs. 6 and 7 of the drawings.
Partitions, which may or may not be cast in one piece with the combustion chamber,
and which are preferably made of copper-plate or other good conducting material
divide the jacket into a canal sufficiently narrow, that at every stroke the air
necessary for the same passes through this canal, which serves as an evaporator and
spray producer. With this appliance may be combined the internal evaporation
described in my English patent specification No. 12896 of 1885.
The canal may form helical or annular convolutions, as shown in Figs. 1, 2, 3,
6 and 7; or as a vertical zig zag line, as shown in Figs. 4 and 5 ; or a combination
of both. The bottom of this canal where the liquid fuel tends to collect, is filled with
metal shavings, (preferably copper), which act like knife edges in dispersing the fuel
through the air current. The globules projected against the walls are evaporated as
far as possible. The fuel enters in accurately measured quantities, through a pipe r,
Fig. 1, at the top, into the evaporating space V, into which air is admitted from
below, and from which the mixture is discharged at the top, being sucked by the
pump of the engine. A small tubes, fig. 1, serves to suck upwards any liquid that
may have collected at the bottom. The annular or helical partitions which form the
evaporating canal may be made separate from the combustion chamber, and of a
different material, preferably copper.
The engine may also be worked with a heterogeneous mixture, if the same is so
constructed that a good mixture of gaseous fuel occurs only at the point of ignition,
and the ignition is transmitted from the latter to any convenient quantity of fuel
mixed with air. If, as usual, the engine is so constructed that the ignition takes
place at the entrance of the mixture to the combustion chamber, the petroleum is
admitted into the combustion chamber, and the gaseous mixture afterwards.
In engines working like Otto's, with a residue of products of combustion, there
would thus occur a sort of stratification, so that the misty mixture would be situated

page_text: between the residues of combustion and the inflammable mixture, but without any
sharp limit. To obtain this heterogeneous and stratified charge, I may use the same
evaporating and atomising apparatus described above; the light fuel, and also the
illuminating gas being admitted to the evaporating chamber at the end only of the
suction period, so that an engine having a cycle of four operations, like Otto's system,
would suck the gaseous mixture last, and the same would then be situated at the point
of ignition.
The same evaporating and atomising apparatus, as described above, may also be
employed for the chemical decomposition of the fuel by increasing the heat in the
furnace or in the combustion chamber of the engine, as is the case in the manufacture
of gas, so that this gas generator supplies gas and air which may be immediately
used in the combustion chamber of the engine. The igniting mechanism serving to
heat the inflammable mixture is of the same type as the mechanism described in my
English patent specification No. 12896 of 1885, and here illustrated by Figures 8 to 14.
The igniting chamber chamber k is separated from the other metallic parts by bad
conductors of heat, and specially heated, partly by the outer igniting flame, and partly
by the inner explosion.
Owing to the horizontal arrangement shown in Fig. 8, the igniting flame may be
placed beneath the said chamber, so that it burns between the chamber and the valve v
before closing the latter. This valve is pressed on its seat in the igniting chamber
by the lever mechanism shown in Fig. 8, and thereby an explosion produced in the
igniting chamber k.
To transmit the said explosion from the igniting chamber k into the combustion
chamber K, the igniting box may be shifted and thereby the pressure chamber K
opened as represented in Figs. 8, 9, 10, and 13, or the igniting box may be stationary,
and fixed as shown in Fig. 14, the connection of the igniting chamber k with the
pressure chamber, (or power cylinder), K being effected by a little check valve, the
small bore of which supplies to the igniting chamber the mixture, the explosion of
which opens the valve to the power cylinder.
When the valve v opens, the displaced igniting box is replaced into the position
before ignition by a spring n, Fig. 8, so that the power cylinder is closed while the
supply ports are open. Figs. 11 and 12 represent suitable forms of the separating
plate arranged in the igniting chamber k, and through which on the closing of the
valve v, the spark returns into the igniting chamber; the certainty of ignition
depends in a considerable degree on the shape and width of this aperture; shown in
Figs. 11 and 12.
In order to heat the igniting mixture with greater certainty before its admission to
the igniting chamber, the latter is surrounded by a jacket M, (see Fig. 13), which
supplies the chamber k with the inflammable mixture.
The inlet and outlet ports of the said igniting chamber jacket are closed and opened
at the same moment, when the communication between the igniting chamber with
with the working mixture K is established or interrupted. Thus the igniting chamber
is not filled directly from the source of the mixture, but only after the mixture has
been first heated in the jacket M, Fig. 13.
Having now particularly described and ascertained the nature of my said Invention,
and in what manner the same is to be performed, I declare that what I claim is :-
1. The above described method of employing non-volatile liquid fuel in a petroleum
motor which consists substantially in the combination of the following means or
processes:
a. Mixing or diluting non-volatile liquid fuel with volatile hydro-carbons.
b. Previous heating of the fuel for the purpose of fine distribution.
c. Its dispersion as a mist by means of a current of heated air in a proportion to
produce a combustible mixture.
2. The method described of forming a combustible mixture for petroleum engines,
which consists in causing the liquid fuel and air to pass in a helical, coiled, or zig zag
line through the jacket of the combustion chamber of a petroleum motor, or through

page_text: the jacket of an ordinary furnace, before the mixture is admitted to the working
cylinder.
3. The above described method of forming a combustible mixture of non-volatile
liquid fuel, which consists in chemically decomposing said fuel by causing the same
to pass through a helical, coiled, or zig zag canal surrounding a furnace or the
combustion chamber of an engine, and in mixing it with the necessary quantity of
air, before its admission to the working cylinder.
4. In a petroleum engine, a heating jacket surrounding a furnace or combustion
chamber of the engine and containing partitions of copper or other suitable metal,
arranged so that the fluid or mixture passing through the jacket is compelled to take a
helical or zig zag course, substantially as described.
5. An igniting chamber provided with a jacket M through which passes the igniting
mixture for the purpose of being heated before its ignition, substantially as described
and illustrated by Fig. 13.