IMPROVED APPARATUS FOR TESTING MINERAL OILS AND OTHER INFLAMMABLE LIQUIDS
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by William Clark at the Office
of the Commissioners of Patents, with his Petition, on the 7th
September 1874.-A communication from abroad by Emile
Granier, of Paris, France.
I, WILLIAM CLARK, of 53, Chancery Lane, in the County of Middle-
sex, Patent Agent, do hereby declare the nature of the said Invention
for "IMPROVED APPARATUS FOR TESTING MINERAL OILS AND OTHER INFLAMMABLE
LIQUIDS," to be as follows :-
This Invention relates to apparatus for ascertaining the temperature
at which mineral oils and other volatile liquids evolve gases or vapours
which will ignite on coming in contact with a flame. The advantages
desirable from the use of such an apparatus are that the employment of
another liquid for heating that which is to be tested is rendered
unnecessary, nor is there any need to have recourse to any scientific or
chemical aids, the manipulation of the apparatus being as simple as that
of filling and trimming a lamp. The indications are also given at the
same time in a manner calculated to defy all fraud or negligence.

page_text: The Invention is illustrated in the accompanying Drawings in which
a, Figure 1, represents the vessel for holding the liquid to be tested, the
level of which latter should not be higher than the top of a small
regulating tube c, which receives the excess of liquid so that the amount
always remains constant throughout the experiments; d, central conical
chamber for dividing the liquid to be tested from the portion required
for the supply of the wick e, which is of such length as to just protrude
above the wick tube f in order that it may burn without smoke; g,
conical projection on which the wick tube f is fixed in position.
If the liquid to be tested be slowly poured on the central tube f until
it overflows the conical chamber d, the vessel a will be fitted to the level
b, while sufficient will remain in the chamber d for the supply of the
wick, and for heating the liquid in a to be tested to a temperature of
150 degrees Fahrenheit; h, cover hinged to the apparatus a and two
openings in the one which is lined with some non-conductor, a
thermometer is inserted so as nearly to touch the bottom of the vessel,
while the other opening i serves for the escape of the vapours or gases
disengaged by the liquid being tested; j, small cap or cover hinged to
the central opening in cover h, and provided with a small central
opening, at which the vapours or gases of highly volatile liquids may
be instantly ignited at low temperatures with the aid of a lighted
match; p, cross wire of copper for preventing the wick from rising
higher than is required, and also serving to impart the heat of the flame
to the liquid to be tested; q, small hole made in neck i for supplying air
for feeding the flame k. The conical chamber d contains sufficiént
liquid to feed the wick and raise the temperature of the liquid to be
tested to 150 degrees Fahrenheit, which is sufficient for all practical
purposes, but if a still higher temperature is required I construct the
apparatus with a false bottom r, as shown in Figure 2, which is placed
in communication with chamber d by increasing the length of the wick;
8 safety tube for preventing too great a pressure being formed below the
false bottom.

page_text: alcohol which should be completely immersed in the liquid to be tested;
m, metallic casing of the thermometer to protect the latter from injury,
having openings around the bulb n and two graduated scales arranged
parallel, so that the indications may be readily read off at the moment
of making the test; a, lining of cork or other suitable substance.
The method of using the apparatus is very simple as will appear from
the following description:-The cover his first raised and the wick
placed in the proper position for lighting, as before-mentioned, the liquid
to be tested being then slowly poured onto the wick until it overflows
into vessel a and rises on a level with tube c. The cover h is then care-
fully shut as well as the small flat cover j, and the thermometer
introduced which, owing to the escape provided by the overflow pipe c,
does not raise the level of the liquid. A lighted match is then applied
as a precaution at opening of cover j, when if the liquid in the appa-
ratus be highly volatile, such as naptha for example, and even without
heating the apparatus vapours will be evolved which on the application
of a lighted match will ignite, and continue to burn above the cap i
with a small flame k, as seen in Figure 1; this flame should however be
then extinguished.
Should the liquid in the apparatus (without being as volatile as that
above mentioned) emit gases or vapors at a temperature below that of
the place in which the experiment is made, the simple application of a
lighted match to the aperture z will ignite these vapors, and produce a
slight explosion which will extinguish the flame. If however on the
application of a match to the said aperture z neither the flame nor an
explosion is produced, it is evident that the liquid in the apparatus
requires heating to a higher temperature, and in this case it is necessary
to raise the small cover j, as shown in Figure 2, and light the wick.
This being done care should be taken not to move the apparatus or to
produce the least current of air which would be liable to cause the flame
to enter the apparatus, and prematurely ignite the liquid to be tested.
A few minutes only suffice to raise the temperature of, for example,
petroleum oil to 176 degrees Fahrenheit. Immediately the lighter
vapors or gases are developed by the heat of flame, t, Figure 2, they will
rise through the aperture i of the cover h, and coming in contact with
said flame t will become ignited and produce a flickering, which con-
tinues until more of the vapours become lighted, and spread the flame

page_text: over the whole surface of the liquid under trial, when a slight explosion
will take place, which is however immediately extinguished by the
apparatus itself. Thus there is no danger of accident ensuing from the
experiments, which may be conducted by any person in order to judge
of the quality of an oil.
On the first appearance of any movement of the flame the ther-
mometer should be examined to ascertain the temperature of the liquid
at this moment, which I term the "point of ignition" continuing to
watch the thermometer until the explosion takes place which extin-
guishes the flame, and this I term the "point of combustion."
In order that the apparatus required for testing the qualities of
petroleum used for lighting purposes may be arranged in a convenient
manner for the use of manufacturers and dealers in petroleum, I enclose
them in a case, see Figure 7, which shows in separate compartments, 1st,
a graduated testing glass 1, and 2ndly, a densimeter 2 graduated from
100 to 60 which are the extreme densities of mineral oils. By pouring
1.76 of a pint into the test glass 1, and then placing the densimeter 2
therein, it will show whether a litre (or 1·76 of a pint) has a specific
gravity of 24 or 28 oz., according as it floats at 70 or 80 degrees. In
this manner the exact weight of a supply may be calculated according
to the number of litres or the number of litres if the liquid is supplied
by weight.
After ascertaining the density of the oil by the above means, it is
poured into the testing apparatus herein-before described, when the point
of ignition will be at once indicated by the thermometer.
In order to avoid the liability of the "densimeter" being broken
during the experiments, I fix it in the testing glass in such manner as
will allow of its moving vertically, and floating in the liquid at the same
time that it is prevented from falling to the bottom of the testing glass
when the latter is empty. This arrangement enables the testing glass
to be filled and emptied without handling the densimeter, while the
latter may also be readily removed for the purpose of cleansing the
testing glass; Figure 8 shows one example of the above arrangement;
1, glass; 3, spring holder attached to and resting on the bottom of
the glass through an orifice 4, in which holder the stem of the
"densimeter" is introduced, but which orifice is made so small as to

page_text: prevent the bulb passing; 5, casing of wirework having sufficient
clasticity to prevent the densimeter breaking in case of falling. This
casing is attached to the limbs of the spring holder 3 near their lower
ends. The case, Figure 7, also contains the testing apparatus,
Figures 1, 2, and 3, the thermometer enclosed in metal, and a few
wicks e cut of the desired length.