Alpena weekly argus. [volume] (Alpena, Mich.) 1871-1893, 1882-08-09
The Cause OF Explosion in Kerosene
Lamps.


The Tcch,.olo1ische Bldtter, of Vienna,
contains u scientific disquisition by Z.
Knopp upon the causes upon which de-
pend the explosions too frequently
noticed in petroleum lamps.
The combustible hydrocarbon gases
formed by the evaporation ofpetroleum
burn easily, and when mixed in certain
proportions with oxygen gas they
burn so rapidly rs TO produce q violent
explosion. This takes place when one
part of the vapor is mixed with two
parts of air. This gaseous mixture ex-
pands at the moment of ignition and in
consequence of the heat generated, so
that it far exceeds its former volume,
and il makes room for its increased
bulk by destroying tho surrounding
bodies. The explosions that occur in
petroleum lamps have their origin in
the existence of such explosive gas
mixtures. What remains to be shown
is: first, how such mixture is formed
in the receptacle; and secondly, in
what manner it can be ignited.
The oil receiver, which in the major
ity of kerosene lamps consists of glass,
has only one opening which is provided
with metallic collar. This is used
both for filling the lamp and for receiv-
ing and holding the burner. This re-
ceptacle, and the oil contained in it,
when the lamp is burning, acquire a
certain temperature, which is different
under different circumstances, but
in nearly all cases it is high enough
to generate these hydrocarbon vapors.
The higher the temperature of the oil
in the receiver the more rapid, of
course, will be the evolution of vapor.
Every burner, consisting of a good
conductor, becomes heated by the
flame and communicates this heat to
the petroleum holder. Since heat and
light are very nearly related this de.
velopment of heat will increase in pro-
portion to the illumination given by the
lamp. For example: if lamp that
gives poor light is burning in a cold
room no vapors will be generated at
all. On the other hand, if lamp that
gives good light burns in a well-heat.
ed room, at short distance from the
ceiling, whore the temperature, owing
to the ascending heated air, often ex-
ceeds 80 degrees Il. 600 degrees Fab },
and in addition to that q shade is sus-
pended above it and thus reflects the heat
down upon it, there will be rapid
evolution of gas and vapor. get these
hanging lamps very rarely explode, be-
cause they are let alone.)
Now let us imagine that lamp has
been filled to the rim with oil before
the wick is lighted. The petroleum is
consumed by the flame, and hence the
volume of oil in the lamp gradually
decreases. Tho empty space thus
formed, so long rs little or no vapor is
generated, will be filed with atmos-
pheric air sucked in through the burn
CT. 1t is absolutely impossible to pre-
vent this entrance of air; for il it were
technically feasible, vacuum would be
formed in the lamp, and the oil could
not be drawn up the wick to the flame,
so that the burning of the lamp would
be hindered if not entirely prevented.
This admission of air, combined with
the gases evolved in the lamp, are
adapted to the production of the ex-
plosive mixture.
We now como TO the question of
how it is possible for this mixture to DO
ignited.
In all the burners hitherto in use in
Germany the flame is regulated by
showing the wick up or down in the
metallic case by means of ratchet
wheel ut the lower part of the burner
and attached TO projecting wheel and
axle. Owing TO the softness and 1exi-
bilty of the wick this movement is pos
sible only when the wick is rather loose
and has some play in the tube. This
space, which is frequently increased
accidentally stih more by the wick be-
ing too small or thin, would be of no
SO long rs il merely per-
mitted the atmospheric air TO enter the
oil holder, for this access of air, as al
ready remarked,is not to be prevented,
but rather aided. Unfortunately this
space permits the gases rising from the
oil to reach the flume, which is sure to
take place rs soon rs there is the slight
est pressure in the receptacle. This
pressure, however, is necessarily pro-
duced by the development of gases in
the holder.
If, now, these gases are pressed up
ward through the wick space by the
side of the wick, they reach the flame
and are ut once consumed there with
out any explosive action rs long rs the
gas is not mixed in the requisite pro-
portions with the atmospheric air.
Since this intermixing may take place
in many different ways, we can explain
in this way the many explosions and
the greater or less danger with which
they are attended.
If no explosive mixture of gases has
been formed in the receptacle itself, but
only in the tub with the wick, the explo-
sion will be but n slight puff, accompa-
MED by ilickering of the flame and the
evolution of some smoke. This little
explosion will be more violent and moi
sly the greater the volume of explosive
gases that have collected in this wick
tube, the burning gases will burst out
below because of their expansion at
the moment of combustion. In such
cases blush flame can be distinctly
seen to descend into the oil cup or
holder. This flame is Immediately OK
tinguished without any injury being
done, provided there is no explosive
mixture present in the oil receptacle
itself, because the force generated by
the expansion of so small a volume of
gas rs that burned in this case, does
not suffice, as rule, to break or injure
the receptacle. If, however, there is
an explosive mixture in the receiver
itself, an explosion can not but take
place, and its violence again will de-
pond upon whether all the space in the
receiver above the surface of the oil is
filed with the explosive mixture of air
and vapor, or only part of it.
We may add that the less oil there
is in the lamp the larger the space
which may or may not be filled
with this dangerous mixture. The
relative safety of an oil is
judged by the temperature at
which it gives off combustible vapors,
but in lamp where u certain degree of
rarefaction may exist il is quite possible
for these vapors to be generated few
degrees lower than i'm the usual petro-