Year: 1887

page_text: I FREDERICK HALL SNYDER, of Jersey City, New Jersey, United States of America,
Engineer, 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:-
My invention relates to a novel method of obtaining purified gas-carbon, that is to
say, gas-carbon from which all mineral and metallic elements and soluble salts are
removed or eliminated. It also relates to the manufacture of various articles from
such purified gas-carbon.
The crude carbon found adhering to the interior of retorts used for the manufacture
of illuminating gas, differs essentially in all its physical characteristics from other
forms of carbon, and, when purified by the process or method of treatment herein
described, possesses, in a higher degree than any other forms of matter known to me,
the essential properties desired in material for the manufacture of articles such as
filaments for incandescent and pencils for arc electric lights.
The crude substance is the result of decomposition, by heat and pressure, of the
volatile hydrocarbon of the coal, and it is deposited under varying conditions and,
in a measure, with varying results as to its value for use in the arts or industries. It
is comparatively pure as it comes from the retorts, having been freed in the process of
its production from nearly all foreign matter. It has, therefore, hitherto been regarded
as a pure product, or, in other words, as being as nearly pure when taken from the
retorts as it could be obtained.
I have discovered that this substance is composed of carbon in different conditions,
that is to say, of different grades or qualities, and of soluble salts and other foreign
matter constituting impurities which impair the most valuable properties of the carbon.
I have also found that the washing or treatment by elutriation of the pulverized
crude product will remove or eliminate all the soluble salts, and that, by reason of the
difference of specific gravity of the different grades or qualtities of this material,
particles or pieces of superior quality may be separated from those of inferior quality,
Pain Q17

page_text: Figure 2 is a horizontal section of a safe, the lining of which is composed of slabs
of the purified gas-carbon.
Figure 3 is a section of a slab of carbon such as I sometimes use in lining safes.
Figure 4 is a vertical central section of a crucible lined with the purified gas-
carbon.
Figure 5 is a vertical transverse section, showing a journal-bearing made of the
said carbon.
In separating the purer carbon from the crude substance by clutriation, I take
crude gas-carbon as it comes from the retort, and pulverize it by any of the well-
known methods for reducing hard substances, as the material is very refractory; care
should be taken to use an apparatus which will reduce it as nearly as practicable to an
impalpable powder. From the pulverizer I convey the material to the first of a series
of tanks, as shown, for example in Figure 1. These tanks, which are to be continu-
ously supplied with water, are so arranged that the water will overflow continuously
from No. 1 into No. 2 and so on throughout the series to No. 5. I have shown five
tanks in the drawing, but the number and size of the tanks may be varied provided
that a sufficient area and number are used to separate the carbon into the different
grades required. The continuous supply of water sufficient to produce the proper
overflow is admitted through the pipe A into the tanks No. 1; the outlet for the
water is shown at B. Crepresents the pipe through which the pulverized carbon is
admitted into the tank No. 1. I prefer to make the last tank in the series, which, in
this instance, is represented as No. 5, of greater length proportionately than the other
tanks. In practice, this apparatus may consist of a single tank which is divided by
suitable partitions as shown in the drawing. In the upper part of the tank No. 5, 1
arrange partitions D, D, D, which extend below the surface of the water in the said
tank, and prevent the washing away of the lighter material which accumulates in this
tank. The carbon being received in tank No. 1 is thoroughly agitated by the current
of water, and the coarser and heavier particles and impurities are precipitated in this
tank the valuable portion of this material passes over to tank No. 2, where the same
process is repeated, and so on continuously, through the series until the last tank is
reached, where the partitions D, D, D retain the purest carbon, and where this carbon
may be collected. It is obvious that a proper relation should be preserved between
the quantities of carbon, and the quantity of the inflowing and outflowing water.
I have above described a process for separating the valuable portion of gas-carbon
and one that will be found useful in practice, but other methods may be employed by
which the same result may be obtained.
In separating the purer carbon from the crude substance in the dry way, by
gravitation or precipitation, I take the pulverized carbon and drive or force it by
means of a rotary or other suitable blower into a depositing chamber, this chamber I
prefer to make narrow in width but of considerable length and height; upon the
bottom or floor of this chamber, I place partitions which extend across the chamber,
and are of sufficient height to form bins for separating and holding the different
grades of carbon that fall upon the floor in their passage from the blower through the
chamber.
It will readily be seen that the fineness and purity of the different grades of carbon
between the partitions in the several bins, will be approximately proportionate to their

page_text: distance from the opening of the blower, the heavier material settling in the bins
nearest, and the lighter material in those furthest from the blower.
This material obtained from either of the above described methods, or others
analogous thereto, is now ready for use. It may be moulded under pressure into any
suitable form in combination with any adherent substance, or otherwise, and presents
in this form, all, or nearly all, the characteristics of pure carbon.
Having described the process by which I free the gas-carbon from impurities and
thus obtain a pure, or practically pure, carbon, I will now proceed to enumerate some
few of the uses to which the carbon may be put in the arts or industries.
In Figures 2 and 3, 1. have shown the carbon as moulded into blocks or plates for
the linings of safes, and in Figure 4, I have shown it applied as a lining for a crucible;
while, in Figure 5, I have shown it applied to a journal-box or bearing for a shaft or
the like.
In preparing the carbon for the uses above named, if it has become caked in the
process above described, it is pulverized or reduced to a finely divided condition; the
pulverized carbon is mixed with coal-tar, asphalt or other suitable binding material,
after which it is moulded under great pressure, so as to form a hard, dense and com-
pact body of any desired shape; the blocks or pieces thus formed are burned or baked
in a suitable oven or kiln and are subjected to a temperature sufficient to drive off or
consume the hydrocarbon or other binding material employed,
In making plates for the linings of safes, I prefer to mould them with corrugations
or projections in one side as shown in Figure 3. The thickness of these plates may
bear such relation to the thickness of the walls of the safe that an air-space, as shown
at a in Figure 2, will be left between the two plates b, c, the inner plates being
corrugated on their inner faces, and the exterior plates c on their outer faces.
The section shown in Figure 2 is intended to represent a safe lined with carbon
prepared according to my invention; the part E of this safe is shown provided with
the moulded corrugated plates; the other part F is shown provided with a lining d, d¹
of carbon inserted therein in a plastic condition by ramming or tamping in a well-known
In the latter case, an air-space may be formed in the carbon, if required,
by using a core which is withdrawn after the tamping is completed; or thin walls or
diaphragms of sheet iron may be inserted so as to produce the same result.
manner.
When it is desired to produce a porous article possessing still greater non-conduct-
ing qualities, I mix, with the carbon and binding material, sawdust or foraminous
substances which will be consumed when the article is burned or baked in the kiln,
thus leaving the article open and porous. When, however, the article is to be subjected
to heavy strain, as in the case of journal-bearings for shafts, axles or the like, the
carbon is moulded into form under great pressure so as to render it as dense and
compact as possible and capable of resisting great strains.
In Figure 5, I have shown, in transverse section, a shaft or axle G supported in a
bearing H of carbon.
I have found by experiments made with the gas-carbon and with articles made
therefrom that, when properly prepared, the said carbon can be used with great
advantage for many purposes where it is desired to resist the action of heat, and there
are a variety of ways in which it may be prepared and used.
For using it to take the place of fire-brick or for lining crucibles for the reduction
of metals or the production of steel by the Bessemer or similar processes, I prefer to
finely pulverize the carbon and afterwards mould it into the desired form under
pressure and then bake it in an oven or kiln. It may, however, be used in a plastic or
semi-plastic state and applied as a mortar for the lining of crucibles, for the coating of
the outer surfaces of steam-boilers, pipes or cylinders, hot-air furnaces, or similar
objects, any suitable cementing material being used to reduce the carbon to a plastic
or semi-plastic condition. For this purpose, I prefer to use coal-tar, asphalt, resin or
other material of a similar nature containing volatile hydrocarbon; from two to three
per cent. of the hydrocarbon may be mixed with the carbon, using a sufficient heat to
mix and thoroughly intermingle the cementing material with the carbon. When the
compound is to be used for coating the exterior of heated surfaces, cementing material

page_text: of a different nature may be used according to the degree of heat to which the com-
pound is to be subjected. For coating outer surfaces subjected to great internal heat,
such as furnaces or hot-blast pipes, cementing material of a nature similar to that
above named may be used for coating boilers, steam-pipes or the like, however, where
less heat is attained and it is desired to make a covering possessing greater tenacity,
hard india-rubber or similar material may be used according to the nature and strength
of the compound required.
For producing compounds which are non-conductors of heat, there are many
substances that may be advantageously used and mixed with the carbon, such as
asbestos, mineral wool, tale, pumice stone or clay. These and analogous substances
may be mixed in small quantities with the carbon without materially impairing its
valuable properties.
For making artificial stone for grinding or polishing, finely pulverized emery may
be mixed with the carbon. ·
The purified gas-carbon, when finely divided or reduced to a nearly impalpable
powder, can be used with oil or other substances in the same manner as ochre or other
pigments are used in compounding paints. The merits of a paint of which gas-carbon
is the basis will readily occur to any one familiar with its characteristics, the carbon
has so little chemical affinity for other substances that it cannot be easily affected when
placed in contact with chemicals or liquids which often destroy other forms of paint,
For this reason, a paint composed of gas-carbon, or of which gas-carbon is the base, is
valuable for protecting metal surfaces, as the oxidation of the metal will not injure it.
This paint will be found valuable for coating the bottonis of ships and other vessels
and its refractory properties make it valuable for painting buildings or roofs which are
liable to be exposed to fires, or for painting or coating smoke-stacks and similar heated
surfaces, where the action of the heat is apt to destroy the usual paint compounds. Its
hardness makes it valuable for use in the place of black-lead, lamp-back and the like,
as it will readily mix with other paints.
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 :-
First A method or process of obtaining pure, or nearly pure, carbon from the
deposits of gas-retorts by pulverizing the said deposits and separating or sorting the
different grades or qualities thereof according to their relative specific gravity.
Second The herein described method or process of obtaining pure, or nearly pure,
carbon from the deposits of gas-retorts, consisting in reducing the mass to a fine
powder and then subjecting the same to treatment by a blast or current of air or
water substantially as described so that the heavier portions first fall or settle and the
lighter and purer portions are driven or carried forward and separated or sorted into
different grades or qualities by reason of the difference of specific gravity between the
carbon and its impurities.
Third A refractory compound, for the purposes above specified, of which purified
gas-carbon is the principal ingredient.
Fourth A paint or pigment of which gas-carbon forms the base, as above set forth.
Fifth The manufacture of safe linings, crucibles, furnace-linings and other fire-
resisting and non-heat-conducting articles or objects from gas-carbon purified in the
manner above set forth, mixed or unmixed with other materials.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.