1908 Edition Sent to us by Richard D. Hamp, 1772 Conrad Avenue,
San Jose, California 95124-4501
Capitaine Engine
Before the commencement of his experiments on oil engines, Emile
Capitaine had already gained considerable experience in the design
of gas engines, to the development of which his work in no small
degree contributed. His first oil engine patent dates from 1879,
and from that time until 1886, when a further patent was granted,
he carried out a continuous series of laborious and costly
experiments with a view to devising an engine which would run
satisfactorily on ordinary lighting petroleum having a density of
about 0.88.
Good results were obtained from the early engine, which worked
without either flame or heating tube; but it was found
necessary to give each time a full charge, or at the least 75
percent. Otherwise, if the charge were too small or omitted, the
vaporizer chamber, which was maintained at the necessary
temperature by the repeated explosions, became chilled to too great
an extent. From this it will be evident that the engine could only
work under certain conditions. Numerous experiments were also made
with a view to arriving at a type of engine which would work
equally efficiently at full and low loads, the consumption of oil
being proportioned to the power developed. Two new patents were
obtained for a system of regulating the temperature, but the gear
was of too complicated a nature, and finally, after much
experimenting, Capitaine adopted the lamp heating system, which has
given very good results. In this later type of engine the vaporizer
remained always in communication with the interior of the cylinder,
but its form was such that even when heated to redness premature
explosion of the mixture did not take place, and the formation of
carbonaceous deposits on the inner surfaces was entirely
avoided.
In the Capitaine engine of 1892-1893, although a vaporizer lamp
is provided, it may be dispensed with, as the engine can also work
on the pneumatic system employed in the 1886 type, with, as before,
the conditions that the charge must not be less than 75 percent of
the full amount, and that the number of explosions must not be
reduced. Considering the uniformly good diagrams that are
obtainable from the Capitaine engine without a heating lamp, when
the temperature of the vaporizer varies within considerable limits,
all that is necessary for successful working is to enclose the
vaporizer and to allow it to retain as much as possible of the heat
of each explosion. Above all, it is essential to protect it during
the suction period from the contact of cold air or gas at a lower
temperature. By observing these conditions Capitaine has succeeded
in devising a type of engine which gives excellent results and does
not involve the use of a heating lamp. By carefully coating all the
surfaces with refractory non-conducting materials, he has also
succeeded in placing the vaporizer within the combustion chamber
itself. In this arrangement, which forms the subject of a separate
patent, a quantity of hot and expanded gas is allowed to pass into
the vaporizer by means of a small valve, which opens at the end of
the expansion stroke, and closes immediately thereafter, when the
large exhaust valve is opened. To start the engine from the cold
condition the vaporizer must first be heated by means of a hand
lamp for two or three minutes.
The characteristic features of the engine may be summarized as
follows:
1. It dispenses with a heating lamp or other similar gear; 2.
Only two or three minutes are required for the starting of the
engine, owing to certain features in the design of the vaporizer:
(a) the limited admission of air; (b) its inclusion in the
combustion chamber; (c) the use of non-conducting coverings; and
(d) the use of the very hot gases for heating it; 3. The vaporizer
is not cooled during the suction stroke; or when explosions are
missed for the purpose of economically regulating the speed.
Crossley Engine
This engine is the same as that already described in the section
devoted to gas engines, with the addition of a special type of
vaporizer, which enables a combustible mixture of air and oil
vapour to be used instead of coal gas. The vaporizer consists of a
chamber divided by vertical walls into four canals, through which
the flame from the lamp passes upwards to the exit chimney at the
top, while a single-acting pump driven by a lever forces a stream
of air through a hot spiral passage encircling the lamp chimney.
After its passage through the spiral the heated air comes into
contact with the oil, a portion of which is entrained and carried
over. Instead of the wick customarily used in the heating lamps of
other engines the system of feeding the oil by means of a small
pump has been adopted, and after the engine is well started the
lamp is not required, as the heat of the explosions maintains the
temperature of the vaporizer. Various modifications and
improvements of this engine have been made since its first
appearance, the principal being the reduction of the time required
for the preliminary heating of the vaporizer when starting the
engine, and the simplification of the valve mechanism. Fig. 384
illustrates a moderate-power type of Crossley oil engine in which
any grade of refined or crude petroleum may be readily burned, and
other examples are given in Figs. 385 and 386.
Engines of very similar construction are also manufactured by
Messrs, Crossley for burning petrol or benzene, as in Fig. 387,
which shows an entirely self-contained portable engine of 3?
B.HP.
