We give in the accompanying figures the arrangement of the different
apparatus necessary for the manufacture and compression of illuminating
gas on the system of Mr. Pintsch, as well as the arrangements adopted by
the inventor for the lighting of railway cars and buoys. This system has
been adopted to some extent in both Germany and England, and is also
being introduced into France.
[Illustration: WORKS FOR THE MANUFACTURE OF OIL GAS.--ELEVATION AND
PLAN.]
The Pintsch gas is prepared by the distillation of heavy oils in a
furnace composed of two superposed retorts. The oil to be volatilized
is contained in a vertical reservoir B, which carries a bent pipe that
enters the upper retort, A. The flow of the oil is regulated in this
conduit by means of a micrometer screw which permits of varying the
supply according to the temperature of the retorts. In order to
facilitate the vaporization, the flow of oil starts from a cast-iron
trough, C, and from thence spreads in a thin and uniform layer in the
retort. The residua of distillation remain almost entirely in the
reservoir, O, from whence they are easily removed. The vapor from the
oil which is disengaged in the vessel, A, goes to the lower retort, D,
in which the transformation of the matter is thoroughly completed. On
leaving the latter, the gas enters the drum, E, at the lower part of
the furnace. To prevent the choking up of the pipe, R, the latter is
provided with a joint permitting of dilatation. The gas on leaving E
goes to the condenser, G G, where it is freed from its tar. The latter
flows out, and the gas proceeds to the washer, J, and the purifiers, I
and I, to be purified. The amount of production is registered by the
meter, L.
When the gas is to be utilized for lighting railway cars or buoys, it
is compressed in the accumulators, T, which are large cylindrical
reservoirs of riveted or welded iron plate.
Compression is effected by means of a pump, F or F', which sucks the
gas into a desiccating cylinder, M, connected with the gasometer of the
works The pump, F, which is used when the production is larger than
usual, has two compressing cylinders of different diameters, one
measuring 170 millimeters and the other 100. The piston has a stroke of
320 millimeters. The two compressing cylinders are double acting,
and communicate with each other by valves so arranged as to prevent
injurious spaces. The gas drawn from the gasometer is first compressed
in the larger cylinder to a pressure of about 4 atmospheres; then
it passes into the second cylinder, whence it is forced into the
accumulators under a pressure varying from 10 to 12 atmospheres.
For a not very large production, the small pump suffices. This has a
single compressing cylinder connected directly with the piston rod, upon
which acts the steam coming from the boiler, K. This pump compresses the
gas to a pressure of 10 atmospheres, and is capable of storing seven
cubic meters of it per hour.
The carburets of hydrogen which separate in a liquid state through the
effect of the compression of the gas are retained in a cylindrical
receptacle, V, which is located between the pump and the accumulators,
T.
Besides the necessary safety apparatus, there is disposed in front of
the condensers a special valve, N, which allows the gas to escape into
the air if the retorts or the purifying apparatus get choked up.
When the oil gas is not compressed it possesses an illuminating power
four times greater than that obtained from coal gas; and, while the
latter loses the greater part of its luminous power by compression, the
former loses only an eighth. It is this property that renders the oil
gas eminently fitted for lighting cars, and it is for this reason that
several large European railway companies have adopted it.