Improvements in the Manufacture of Artificial Fuel.
Year: 1894

page_text: Date of Application, 14th Nov. 1894
Complete Specification Left, 21st May, 1895-Accepted, 22nd June, 1895
Improvements in the Manufacture of Artificial Fuel.
We, WILLIAM HENRY BIGGS, of 83, Stacey Road Cardiff, and ROBERT
RELPH GREENHOW, of Llanishen, both in the County of Glamorgan, Gentlemen,
do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in the manufacture of artificial fuel from
anthracite coal or other coal of an anthracitic nature.
Heretofore when attempts have been made to employ anthracite coal for the
purpose of producing blocks or briquettes of artificial fuel it has been found that
on subjecting such fuel to heat in a stove, grate, furnace or the like, the particles of
coal composing the briquette, instead of burning, have fallen through the fire-bars
in an unburned condition owing to the incapability of the particles of coal to hold
together or coke under the action of heat and thus the fuel so prepared has been
found more or less impracticable for all ordinary purposes.
Now we have discovered that this failure as regards artificial fuel made from coal
of an anthracitic nature, is entirely due to the fact that such coal has been treated
in the manner which is generally adopted in respect to the production of artificial
fuel from bituminous and steam coal, that is to say the particles of coal employed
have not been sufficiently fine to obtain the requisite adhesiveness of the particles
which is necessary to produce caking of the mass when in the fire. The essential
feature of our invention therefore consists in reducing the anthracite coal, or other
coal of an anthracitic nature employed, to a very fine powder, the degree of fineness
to which this powder is reduced ranging from that of an impalpable powder up to
a condition in which the particles will pass through a sieve of 20 wires to the
lineal inch.
The coal having been thus reduced to the requisite fineness, which may be
effected by means of appropriate grinding or disintegrating machinery, we
thoroughly mix therewith a suitable quantity of pitch and coal-tar or other suitable
binding material, into which mixture steam is injected, the pitch being reduced to
approximately the same degree of fineness as the coal with which it is mixed. The
percentages of the pitch and tar or other material are such as to enable briquettes
of good appearance to be produced which will coke thoroughly in the fire,
withstand the effects of exposure to water and atmospheric influences, and possess
the maximum amount of cohesion to avoid breakage. We find that about
3% to 7% of pitch and about 3% to 7% of tar are advantageous proportions
to employ when these materials are used.
The mixture thus produced, care having been taken to make it thoroughly homo-
geneous, is then subjected to pressure-say about 2 tous to the square inch-in a
suitable press whereby blocks or briquettes of convenient shape and size are
obtained ready for use.
In order to render the blocks or briquettes smokeless, we may place them in
kilns or ovens, or otherwise heat them to the requisite temperature, so as to drive
off the smoky nature of the pitch and tar without diminishing the adhesiveness and
burning qualities of the blocks or briquettes, and thereby render them more
applicable for burning in closed grates. The by-products resulting from this
treatment may if desired be condensed and collected in any convenient manner.

page_text: By our invention we are able to produce artificial fuel from anthracite coal or coal
of an anthracitic nature, without the addition of any other coal of a bituminous
kind.
Dated this 14th day of November 1894.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.
Improvements in the Manufacture of Artificial Fuel.
We, WILLIAM HENRY BIGGS, of 83, Stacey Road Cardiff, and ROBERT
RELPH GREENHOW, of Llanishen, both in the County of Glamorgan, Wales,
Gentlemen, 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 :-
This invention relates to improvements in the manufacture of artificial fuel from
anthracite coal, or other coal of an anthracitic nature.
Anthracite small coal has long been considered a useless and valueless product
for heating purposes, because in the first place it does not contain any lunips or
granules larger than an ordinary pea, and in the second place it altogether lacks
the binding or coking qualities possessed by steam and bituminous coals. Con-
sequently when attempts have been made to burn such coal like ordinary steam or
bituminous small coal, instead of the particles or granules coking or caking together
and becoming consumed, they have fallen through the grate bars in an unburned
condition.
Attempts have been made to use this anthracite small coal as fuel by blowing it
into furnaces in the form of a spray with a view of its becoming consumed while in a
state of suspension within the furnace. It has also been mixed with various kinds
of agglomerants or binding agents such as pitch and tar to form it into blocks but
the binding agent has been consumed before the anthracite has had time to burn
and consequently the granules composing the authracite, being no longer held
together by the binding agent, have fallen through the grate bars unconsumed.
Silicates of soda and potash and similar materials have also been employed as
binding agents, and although more successful results have been obtained thereby,
so far as the actual consumption of the anthracite is concerned, serious objections
exist to the use of these binding materials in that the blocks of fuel containing
them will not withstand exposure to damp or rain. Moreover when burning, the
fuel blocks assume a viscid condition and after the combustion of such blocks the
silicates are left sticking to the bars and sides of the grate in a form not unlike
glass clinker. The anthracite has also been treated with lime, meal and clay but
without successful results.
Now we have discovered that the failure of these various attempts lies chiefly in
the fact that the particles of anthracite small coal employed have not been in a
sufficiently finely divided condition and consequently the requisite caking or coking
of the mass composing the briquette (which caking or coking is essential to produce
a satisfactory result) has not been obtained.
The essential feature of our invention therefore consists in reducing the
anthracite small coal or other coal of an anthracitic nature employed, to a very
fine powder, the finer the better, and in thoroughly mixing therewith a suitable
agglomerant or binding agent to form the powder into briquettes. The particles
composing the powder should be fine enough to pass through a sieve of 20 wires to
the lineal incb, although we prefer in practice to use a still finer sieve, say 80 wires
to the inch. It is not necessary that the particles should be all of the same size,
they may range from impalpable powder up to the limit of size above stated. The

page_text: binding agents we prefer to employ are pitch and coal tar or other liquid hydro-
carbon. When employing pitch and coal tar we prefer to use them in the
proportion of about 3 % to 7% of pitch and about 3% to 7% of tar.
In order that our invention may be readily carried into effect we will describe an
advantageous manner of producing our briquettes.
We first pass the anthracite small coal employed, such as that known in the
market as anthracite "duff," through a disintegrator or pulverizer of any
appropriate construction that will deliver the "duff" in the requisite state of
fineness hereinbefore set forth. This finely divided "duff" is passed to a mixer
wherein it is thoroughly mixed with say 6% of pitch; the pitch being in a
powdered condition and of about the same state of fineness as that of the "duff."
After the powdered pitch and "duff" have been thoroughly mixed together they
are conducted to a pug-mill wherein they are thoroughly mixed with say 6% of
coal-tar. The resulting mass is then conducted to a chamber wherein steam,
preferably in a superheated condition, is admitted. Or instead of allowing the
steam to come into direct contact with the mass we may provide the chamber with
a steam jacket through which the steam may be circulated.
This operation raises the temperature and greatly assists in producing a
thoroughly homogeneous mass which we then pass into a press whereby it is
moulded into briquettes of the requisite shape and size, each briquette being
subjected to a pressure of about 2 tons to the square inch. The briquettes as they
leave the press are then ready for use.
If it be desired to render the briquettes smokeless, we place them, as they come
from the moulding press, into kilns or ovens, or otherwise heat them to a gradually
increasing temperature of about 800° to 900° C. The moisture resulting from the
steaming process is thus driven off as also are the volatile hydrocarbons of the pitch
and tar, but without diminishing the adhesive and burning qualities of the
briquettes. The gaseous by products resulting from this operation may be collected
and condensed if found desirable.
For the purpose of preventing the briquettes from cracking owing to a too
sudden change of temperature we may pass them slowly through the kiln or oven
by means of conveyors or travellers. In this way the briquettes as they entered
the kiln would be subjected to a gentle heat at a temperature of about 100° C. this
temperature gradually increasing as they advanced further into the kila until the
maximum of 800° or 900° C. were reached. The briquettes would then become
gradually cooled again as they approached the exit of the kiln.
We do not confine ourselves to this manner of gradually heating and subsequently
gradually cooling the briquettes as any other suitable method may be adopted for
the purpose.
By our invention we are enabled to produce briquettes that will cake or coke
independently of each other so that the fuel will always be in a more or less louse
condition while burning and the air to support combustion be therefore able tɔ
freely pass through the incandescent mass. Moreover our briquettes will not be
detrimentally affected by rain or moisture, and are hard and compact enough to
bear "tipping" from a wagon or from sacks like ordinary coal.
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is :-
1. Artificial fuel substantially as described in which anthracite coal or other coal
of an anthracitic nature is employed in such a state of fineness that the coarsest
particles thereof will pass through a sieve of 20 wires to the lineal inch.
2. In the manufacture of artificial fuel from anthracite coal or other coal of an
anthracitic nature which has been reduced to the aforesaid state of fineness, the
admixture therewith of pitch, reduced approximately to the same state of fineness
as the coal, and of coal-tar or other liquid hydrocarbon, substantially in the manuer
and in about the proportions hereinbefore described.

page_text: 3. The treatment of the briquettes, manufactured as claimed in the last preceding
claim; in order to render them smokeless consisting in subjecting them to a gradually
increasing heat which reaches a maximum temperature of about 800° or 900° C.
and gradually cooling them again substantially as described.
4. The manufacture of artificial fuel from anthracite coal or other coal of an
anthracitic nature substantially as hereinbefore described.
Dated this 21st day of May 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicants.