CERTAIN IMPROVEMENTS IN THE TREATMENT OF COAL, AND IN SEPARATING COAL AND OTHER SUBSTANCES FROM FOREIGN MATTERS, AND IN THE MANUFACTURE OF ARTIFICIAL FUEL AND COKE, AND IN THE DISTILLATION AND TREATMENT OF TAR AND OTHER PRODUCTS FROM COAL. TOGETHER WITH IMPROVEMENTS IN THE MACHINERY AND APPARATUS EMPLOYED FOR THE SAID PURPOSES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWPER, of Southampton Buildings, Chancery Lane, in the County of
Middlesex, Patent Agent, send greeting.
T
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of
Great Britain and Ireland, bearing date at Westminster, the Second day
of November, One thousand eight hundred and forty-nine, in the thirteenth
year of Her reign; did, for Herself, Her heirs and successors, give and grant
unto me, the said Charles Cowper, my exors, admors, and assigns, Her
especial licence, full power, sole privilege and authority, that I, the said
Charles, Cowper,, my exors, admors, and assigns, and such others as I, the
said Charles Cowper, my exors, admors, or assigns, should at any time
agree with, and no others, from time to time and at all times during the
term of years therein expressed, should and lawfully might make,. use, exer-
cise, and vend, within England, Wales, and the Town of Berwick-upon-
Tweed, and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, and
also in all Her said Majesty's Colonies and Plantations abroad, the Invention
of "CERTAIN IMPROVEMENTS IN THE TREATMENT OF COAL, AND IN SEPARATING
COAL AND OTHER SUBSTANCES FROM FOREIGN MATTERS, AND IN THE MANUFACTURE OF
ARTIFICIAL FUEL AND COKE, AND IN THE DISTILLATION AND TREATMENT OF TAR AND
OTHER PRODUCTS FROM COAL. TOGETHER WITH IMPROVEMENTS IN THE MACHINERY
AND APPARATUS EMPLOYED FOR THE SAID PURPOSES," communicated to me from
abroad; in which said Letters Patent is contained a proviso that I, the said
013

page_text: Charles Cowper, should cause a particular description of the nature of the said
Invention, and in what manner the same is to be performed, by an instrument
in writing under my hand and seal, to be inrolled in Her said Majesty's
High Court of Chancery within six calendar months next and immediately
after the date of the said in part recited Letters Patent, as in and by the
same reference being thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Cowper, do hereby declare that the nature of the said Inven-
tion, and the manner in which the same is to be performed, are fully
described and ascertained in and by the following statement thereof, reference
being had to the Drawings hereunto annexed, and to the figures and letters
marked thereon, that is to say:
The Invention consists of four distinct processes, either of which may be
used separately, or the whole may be used in connection with one another,
forming a complete system, which I designate by the term "The Treatment of
Coal."
The first process is the purification of coal, or the separation of coal from
pyrites and other foreign matters; and this process is also applicable to the
separation of metallic ores from earthy matters, and generally to the separation
of substances which differ in specific gravity, and are not injuriously acted upon
by water.
The second process is the coking of coal.
The third process is the distillation and treatment of tar.
And the fourth process is the manufacture of artificial fuel.
FIRST PROCESS. PURIFICATION OF COAL.
Sifting and separating by continuously-acting machinery.-Coal is always
more or less mixed with schist or slaty matters, derived partly from the walls
and roof of the mine, and partly from veins interspersed in the mass of the
coal. When the coal is broken small most of these matters, as well as the
pyrites which generally accompanies the coal, are in detached fragments, sepa-
rate from the fragments of coal, and merely mechanically mixed with them.
The separation of the impurities might be effected by carefully picking them
out by hand, but the expense and tediousness of such a process render it quite
inapplicable. However, that which would be performed with difficulty by
the skill of the hand and the discernment of the eye is easily effected, with
greater perfection and much greater economy, by mechanical means, operating
by the difference of the specific gravities of the different substances. For this
purpose it is first requisite to classify the substances according to their size.

page_text: In Sheet I. of the Drawings hereunto annexed, Figure 1 represents an eleva-
tion, and Figure 2 a plan, and Figure 3 a section of the purifying machinery.
According to local circumstances the coal is either brought at once on to a floor
A, A', on a level with the sieve, or thrown into a pit or trench B in the floor of
the building, from which it is raised by an elevator. A slide C, C', regulates the
quantity taken up by the elevator, which consists of an endless chain with buckets
attached to it. The coal is thus delivered on an inclined plane D, D', which
receives a slight jogging motion from the sieve itself. It is thus conducted to
the classifying sieve E, E¹. This sieve is of the form of a long rectangle, and
is supported on rollers a, a, a, a. It is slightly inclined downwards from the
point where the coal arrives, and this inclination may be varied, and it receives
a rapid motion to and fro, the extent and rapidity of which admit of being
varied. Metallic plates, perforated with holes, are arranged in stages in the
sieve. The largest openings are at the upper part; the plates with smaller
openings are placed on the lower stages, the size of the openings diminishing
as they recede from the elevator; four or five divisions are generally sufficient.
At the sides of the sieve, and at the lower part of each perforated plate, there
are formed openings F, F, F, F, which admit of the escape of lumps which are
too large to pass through the openings in the plates. The plates are inclined
a little at the end towards the openings F on each side, so as to throw off the
lumps of coal. When the coal arrives on the first perforated plate which has
the largest openings, all the fragments of larger dimensions than these openings
will not pass through, but will be thrown off through the opening F on to an
inclined plane which conducts them to a picking table, where the impurities
are picked out by hand. This is easily effected, as the lumps are all large and
free from admixture with small coal, and for the same reason these lumps will
command a good price in the market for domestic or other use. The portion
of the coal and other matters which has passed through the first perforated
plate descends successively from stage to stage over plates whose openings
continually decrease in size, and is thus classified into as many different por-
tions as there are perforated plates, until it arrives at the last plate, which only
admits the passage of a small quantity of very fine powder. This fine powder
does not require purifying, because the friability of coal being greater than that
of schist and pyrites, this powder will be comparatively pure, and if it is
sufficiently fine, and in small quantity, it is superfluous to purify it. It may
be employed at once, like the purified coal, for making coke, and in some cases
may be employed alone for that purpose, or for other purposes. If, however,

page_text: the impurity of the coal is too great, this powder may be mixed with the coal
from which it has been separated by the last sieve, and purified with it in the
manner herein-after described.
However, to meet the requirements of com-
merce in different places, it may sometimes happen that there may be lumps
too small to be economically picked by hand, and too large to be conveniently
purified by the second part of the operation; it will then be advisable to crush
these lumps between a pair of rollers, and then to return them to the sifting or
classifying apparatus by means of the elevator or otherwise. It is convenient
to proportion the sizes of the holes in the various perforated plates, so that the
quantities of coal received in each division may be nearly proportional to the
surface of their respective water sieves herein-after described. These propor-
tions will vary slightly, according to the friability of the coal. The coal from
each division falls at once by means of a hopper into a sieve immersed in water,
which I call a water sieve, and it is in these water sieves that the purification
of the coal from foreign matters is effected. As all these water sieves are
similar, except as regards the size of the openings in the plates or wire cloth
which forms the bottom of them, it will be sufficient to describe one of them.
These water sieves are composed of a large chest or cistern G, G¹, K, K', of
wood or metal, divided into three principal compartments by partitions H, H',
I, I. The number of these compartments can be increased or diminished, but
the division into three is one of the best. A partition L, L', divides the prin-
cipal compartment into two sub-compartments M and M. The last is again
subdivided into two parts M', and M" by the partition N, N'. In the part M
is fitted a piston O. A metallic plate x, x¹, perforated with holes of a smaller
size than the fragments of coal, is placed at a certain distance below. the upper
edge of the compartment M'; this distance is varied a little, according to the
size of the fragments of coal to be purified. The perforated plate may be
inclined at pleasure from the back which is next to the compartment M
towards the front. A slit, the opening of which may be regulated by
a sliding plate, connects the two compartments M and M'. The perforated
plate x, x¹, carries on the side r¹ a small vertical plate or edge, capable of
being raised or lowered so as to regulate the egress of the pyrites, and it also
carries a valve which closes as the water ascends, and opens as it descends. At
the lower part of each of the compartments M and M' is a door for the purpose
The
of removing the matters accumulating in them during the process.
cistern being filled with water, the coal, classified according to size, is con-
ducted by the hopper on to the perforated plate towards the back, where
it meets a stream of water from the water regulator P, placed above.
The piston of the compartment H is now set in rapid motion up and down;

page_text: during its descent it displaces the water in the compartment M", and drives it
up into the compartment M' through the perforated plate. This ascending
motion of the water raises the coal and other substances, and holds them for
an instant in suspension at each stroke of the piston. They then arrange
themselves according to their specific gravity, the pyrites being at the bottom
on the perforated plate, the schist lying on the pyrites, and the coal on the top.
In this manner the rapid up and down motion of the water soon separates the
coal, the schist, and the pyrites into distinct layers or strata. Owing to the
inclination of the perforated plate, and the agitation produced by the strokes
of the piston, the pyrites and the schist pass through the opening and fall
into the compartment. M, which is made large enough to contain the produce
of a day's work, so that it may only require emptying once a day. The current
produced by the influx of water from the water regulator P carries the coal.
forward over the front edge of the sieve, which is lower than the other edges,
and it thence slides down the inclined plane b, b¹, which conducts it at once
into waggons or trucks, in which it is carried away. The inclined plane b, b¹,
being perforated with small holes, close together, the water separates itself
from the coal and falls into a gutter Q, which conveys it into the general
cistern placed behind the range of water sieves at P, P¹.
by the machine, constantly raises the water from the
regulator reservoir P, so that the same water is used repeatedly, and cannot
therefore entail any loss of coal: The small loss of water is replaced
by means of the small pump 0" drawing from a well or other source.
The coal coming from the classifying sieve is constantly supplying the
water sieve, and in the passage of each portion from back to front the separa-
tion of the pyrites and schist is effected.
A pump O', worked
cistern P, P¹, into the
The continuous separation of coal from it impurities may also be effected
in the following manner, which is but a modification of that above de-
scribed-In place of a perforated metallic plate let us suppose a metallic
cloth or net immersed in water in the middle of the cistern, and hang-
ing in its natural or catenary curves, the ends being raised a little above.
the surface of the water at the sides where the coal enters and escapes.
This metallic cloth or net which receives the coal is supported by rollers
placed at intervals; the two ends are carried over the upper rollers, and
united below so as to form an endless cloth or net. The rollers being
now caused to revolve slowly, cause the metallic cloth to advance from the
back, where the coal enters, to the front, where it escapes. The different
substances being arranged in the order of their density by the agitation
produced by a piston, as above described, are carried up the rising slope of the

page_text: cloth above the level of the water, where a vertical plate placed across forms a
variable opening at its lower part, through which passes the schist while the
coal passes over it. The motion of the metallic cloth produces the same effect
which is produced in a simpler manner by the inclination given to the
perforated metallic plate in the first-described arrangement, which I prefer.
In analysing the process of purification it will be seen that it consists of
two distinct operations, following each other uninterruptedly; that is to say,
firstly, the classification in order of size; and, secondly, the water sifting for
the separation in order of density. The classification of coal in order of size
has been heretofore performed as a commercial operation to obtain various
qualities of coal for sale; but the classification by a continuous process, and
for the purpose of being applied to the subsequent operation of purification,
has never hitherto been employed, and such application of it is quite new.
The classification may be effected in a different manner, and with various
modifications of apparatus differing from that above described, while the
principle remains the same. Thus the classification may be performed by
means of a cylindrical or conical sieve, similar to but larger than a flour-
dressing machine, or by means of horizontal plates, with the assistance of
centrifugal force; or sieves of various forms may be employed fixed on the
same plane, and formed of perforated plates or metallic cloth or net, with
various-sized apertures; or, as already mentioned, the plates may be placed
one above another in the same frame; but in whatever manner the classifica-
tion is effected, if it is employed in combination with the water-sifting process
for the purpose of purifying the coal, it will come within the principle of this
Invention.
With regard to the second part of this process, that is to say, the water
sifting for the separation of the substances in order of density, the system
combines several new facts, especially the separation of the different substances
by a continuous process, and the continuous employment of the same water for
that purpose.
It will be easily understood, that the above-described process
and machinery are not restricted to the purification of coal only, but may be
used for separating other solid substances of different specific gravities, provided
that their specific gravities exceed that of water.
SECOND PROCESS. COKING.

page_text: which, being in intimate combination with it, cannot be removed by any
process. Density is obtained by the new methods of manufacture herein-after
described.
My new system of coking may be divided into two distinct parts, having
certain points in common, but adapted for obtaining different results, accord-
ing to the nature of the coal employed. Thus, although the lines of
distinction between bituminous, semi-bituminous, and non-bituminous coal
are not exactly and rigourously defined, I shall describe separately the mode of
proceeding with slightly bituminous coal, or mixtures of bituminous with
non-bituminous coal, and afterwards the mode of coking bituminous coal in
such a manner as to collect that portion of the tar which is in excess above
the quantity required to cause the coal to agglomerate.
The
First Part: Coking of Slightly Bituminous Coal-Sheet II., Figure 1 re-
presents a plan, and Figure 2 an elevation, and Figure 3 a vertical section of a
coke oven formed of two walls A, A, A, A, parallel on one side, and thicker
at one of their ends A', A, than at the other, so that the space between them
is rather wider at one end than at the other, for the purpose of facilitating
the discharging of the oven, as herein-after described. The oven may be con-
veniently constructed of a height of five or six feet, and of a length of ten
or eleven feet, internal dimensions. The brickwork between the walls
forming the floor of the oven slopes downwards a little towards the widest end
of the oven.
Several circular openings in the centre communicate with a
longitudinal flue B, B'. Other semicircular openings along the base of the
walls communicate with two other longitudinal flues c, c¹, cl, cl All these
flues are provided with doors or slides, by which they may be closed.
arch or cover on the top of the oven rests on an iron curb or frame, and is
moveable; it may be raised a little by means of two screws, and pushed on
one side on a railway provided for the purpose. Openings are formed in the
cover for gaining access to the flues or passages formed in the coal, as herein-
after described. The space between the two walls at the widest end forming
the front of the oven is closed by a door or doors, which fill the whole space
except a small portion at the top, which is permanently closed by the masonry.
At the opposite end or back of the oven is another door or doors, which do
not require to be of the full width or height of the oven; an opening is formed
in the centre for the passage of the discharging instrument. The mode of
proceeding is as follows: The oven being already hot from a previous
operation, the cover is raised a little, and run to one side on the railway, so
as to leave the oven completely open. Several cylinders and semi-cylinders of

page_text: sheet iron, made slightly conical, and of a length equal to the internal height
of the oven, and having at their smaller ends a section equal to that of the
openings in the floor of the oven, are placed vertically with their small ends in
these openings. The doors being closed and secured, the coal, previously
moistened with water, is dropped into the oven from a hopper containing the
charge, supported above the oven, and moveable on a railway. As it falls in
it is well rammed, either by hand or by a moveable ramming apparatus, which
may be used for- either of several ovens built in a row. The compression or
ramming should be principally directed round the sheet-iron cylinders and
semi-cylinders, which serve as cores. The bed of coal may be raised nearly to
the top of the large door, and it is then covered with a layer of cinders or
coke dust. The sheet-iron cores are now loosened and withdrawn, thus
leaving flues or passages in the interior of the mass of coal. The cover is now
replaced, and the joints at its circumference covered with cinders or coke
dust. Every thing being thus disposed, the heat of the oven soon ignites the
coal, especially in the semi-cylindrical passages, against the walls of the oven.
The doors E being closed, and the doors F being open, a small quantity of air
is admitted into the side flues C, C¹, C, C, and ascends with the products
of combustion in the semi-cylindrical passages at the sides, descending through
the cylindrical passages in the centre. They then pass through the central
longitudinal flue B, B', into the flues G, G, G", G, where they heat two
adjacent ovens at the same time. Two flue doors near the front of the oven
may be used, or four doors may be used, two in front, and two at the back.
The products of combustion pass from the flues G, G¹, G, G, into the
general flue H, H', after having lost a great portion of their heat, and they
then pass away up a chimney.
having been allowed to take this
opened, and the doors F closed.
The flames and products of combustion
course for some hours, the doors E are
The direction of the current is now reversed,
ascending in the central passages, and descending in the side passages. This
change in the direction of the current is repeated several times during the
operation, so that all parts of the mass of coal are equally submitted to the
action of the heat produced by the combustion of the gas, which heat is also
rendered much more effective than it is in the ordinary coke ovens at present
in use. When the operation of coking is nearly complete, which is known by
the appearance of the flame, all the doors are closed to hinder the entrance of
air, and the coking may be allowed to complete itself slowly for several hours.
The operation may, however, be carried on with great rapidity without fear of
diminishing the quantity or density of the coke. To discharge the oven the

page_text: large door or doors in front of the oven are opened. A box or extinguishing
véssel, made of wrought iron, with a double casing, containing water, and of
rather larger internal dimensions than the oven, is placed against the front of
the oven, of which it forms a sort of prolongation. The door at the back of
the oven is then opened, and on the centre of the uncovered surface of the
coke is placed a plate of cast iron, or of strong sheet iron, strengthened with
iron bars. On the centre of this plate a strong pressure' is exerted by means
of a machine containing a screw or a rack and pinion, which is firmly attached
to the iron binders which sustain the walls of the oven. The discharging-
apparatus is formed of two long iron bars or guides, supported on a carriage
running on the ground or on a railway behind the range of coke ovens. This
apparatus may be attached to the back of either of the ovens by means of two
or more iron rods or hooks, which hook on to the binders which support the
brickwork of the oven. A strong screw carrying a nut is placed between the
two long iron bars, which serve as guides to the nut, which is thus prevented
from revolving with the screw. The extremities of the guides are connected
by a 'cross piece, in which the screw turns, but is not allowed to traverse -
endwise: The screw is surrounded by a cast-iron pipe or a number of iron
bars, which may be covered with clay to protect them from the heat to which
they are exposed in the oven. At the extremity of this pipe is fixed the plate
which rests against the coke. It will then be seen that the pipe and the plate
alone enter the oven, while the screw remains outside. When the pipe is
withdrawn the screw again enters it: This machine being supported on a
carriage may be used for several different ovens. By this means the coke is
pushed as one block into the extinguishing vessel, the door of which is imme-
diately closed. The heat of the coke soon raises steam from the water
contained in the double casing. This steam is conveyed into the lower part.
of the extinguishing vessel, from which it expels the air, and the coke is soon
extinguished, and partially or entirely deprived of sulphur by the steam. The
extinguishing may be expedited by conveying a little water on to the top of
the vessel, which should then be made slightly concave, and perforated with
small holes, which may be opened at pleasure. The water will thus only fall
on the coke in small portions, and will not injure its quality, as is frequently
the case with the ordinary method of extinguishing. This extinguishing
vessel also serves as a waggon for removing the coke to the store sheds or
elsewhere, and one of these vessels serves for several coke ovens. As soon as
one charge of coke has been withdrawn the doors are closed, and the oven
recharged. This system of making coke in long narrow ovens, in which the
depth of the bed of coal is considerable, permits of the production of coke of a

page_text: density depending on the compactness to which the coal is rammed in
charging the oven. The swelling of the coal by the action of the heat is almost
entirely prevented. The pressure thus produced not only increases the density
of the coke, but also facilitates the agglomeration of coals which are only slightly
bituminous. This pressure acting on the walls of the oven is sustained by the
adjoining ovens when several are built in one range. The flues between
the ovens are crossed by small division walls, which sustain the sides, and
cause the flame to follow a serpentine course, and thus to heat the whole
height of the oven. The ramming or compression of the coal in the interior
of the oven, and the mobility of the cover, which renders the ramming
possible, are two facts entirely new, following the one from the other, and for
which I claim protection; they form one of the essential conditions for
bringing the particles into such close proximity as to render it possible to
agglomerate very slightly bituminous coal into lumps of coke.
I also claim the circulation of the flame by alternate ascending and descend-
ing currents in the interior of the mass of coal, which turns the heat to the
best account, and also facilitates the coking of coals containing very little
bitumen. By this means the hydrogenous constituents are retained in much
larger quantity, and the yield or produce is larger. The operation of discharg-
ing the oven is also executed in a manner entirely new, which is also the case
with the operation of extinguishing the coke. The coke is obtained in large
fragments, not being broken into small pieces, as in the ordinary mode of
discharging the oven. I am aware that it has already been proposed to
extinguish coke by means of steam introduced into the oven; but such
method has the great defect of cooling the oven, which is not the case with
the improved method above described. In certain cases, according to the
nature of the coal and the degree of density required in the coke, the interior
arrangement of the oven may be modified in the following manner:-In place
of forming flues or passages in the mass of the coal, a number of vertical
flues may be formed in the brickwork of the lateral walls of the oven and
connected with the oven by numerous small holes of about an inch in diameter,
rising at an angle of about forty-five degrees from the oven to the flues.
These flues unite at their lower ends as in the first-described arrangement,
and convey the gases of the coal into the flues G, G', where they heat the
lateral walls of the oven. By this arrangement the coal can be rammed or
not at pleasure.
Second Part: Coking of. Bituminous Coal and collecting the Tar.-
The arrangements described in the first part of the coking process are
equally applicable to the coking of bituminous coals, but the excess of tar

page_text: above the quantity requisite to cause the coal to agglomerate would then be
wasted. I shall therefore now describe the means of collecting the excess of
tar. The general arrangements are the same as those already described;. I
shall therefore only point out the modifications required for collecting the tar,
and which are shewn in the Figures 4 and 5, Sheet II. In the lateral walls
of the oven, at the points corresponding to the semicircular passages in the
mass of coal, are fixed channels or flues of cast iron a, a', communicating at
their lower parts with a box T, T¹, extending the whole length of the oven. A
sheet iron tube b, b', constantly full of water, serves to keep the channel a, a',
cool. The steam produced passes by a small opening c into the channel or
flue, one side of which is formed by the coal itself. The upper part of the
channel is closed by a plug. The interior of the channel is not in communi-
cation with the upper part of the oven under the arch or cover where the
flames are. The sheet-iron box T, T', which is in communication with. all the
channels on one side of the oven, communicates with the flues G, G¹, G", G",
Figures 1, 2, and 3, by means of two worm pipes immersed in cold water.
Central passages are formed in the coal as mentioned in the first part, and a
flue provided with a door passes through the wall at each side into the flues
G, G, G, G. By opening and closing the doors the currents may be
made to ascend and descend at pleasure. The oven being charged, as above
described, the combustion of one portion of the volatile matters of the coal
will take place in the centre passages by the alternate ascending and descend-
ing currents producing a large quantity of heat. The mass of the coal will
be heated at the same time at the lateral walls, and at the centre and at the
upper and lower parts, to which the flame will be alternately directed. By
the action of the heat the tar will be disengaged from the coal, and the most
volatile portion of it will pass in the state of. vapour into the nearest flues or
passages. That portion which reaches the central passages will be burnt,
but that which passes into the side passages or flues will be collected. For
this purpose it is necessary to prevent the access of air, and to keep the tempe-
rature sufficiently low, which conditions are essential to prevent the inflamma-
tion of these eminently combustible vapours. This end is obtained by the
arrangements described above. The contact of the water tubes b, b, at first,
and afterwards the steam produced in them, cool the flues and at the same
time expel the air from them. The vapours of tar mixed. with steam cannot
inflame, and will be condensed partly in the box T, T¹, and partly in the
worm pipes before reaching the flues. The draught produced by the chimney
suffices to draw the vapours successively through the passages and flues into
the box T, T', where the condensation commences, and afterwards. through

page_text: the worm pipes or condensers. But it must be observed, that when the coal
is very bituminous, the first effect of the heat will be to cause the tar in the
vicinity of the channels or flues to pass off partly in the state of an oily
liquid at once into the box T, T¹, so that a large quantity of tar will be
collected, and in the most convenient form, and almost entirely deprived of the
disagreeable empyreumatic odour which ordinary coal tar possesses. The pro-
ducts collected, and which may be withdrawn from the box T, T¹, by the cock
R, are tar and ammoniacal liquor. A slide V, V', plunged in the liquid at
each extremity of the box T, T', permits of the box being cleaned, by removing
the fragments of coal or coke which may have fallen into it. By these arrange-
ments the coke possesses all the good qualities described in the first part, and
at the same time a considerable quantity of tar and ammoniacal liquor are
obtained without expence, and without interfering with the coking operation;
conditions which have not hitherto been fulfilled. .
THIRD PROCESS.-DISTILLATION OF COAL TAR.
By distillation coal tar is divided into two products having different qualities
First, an essential oil, which is impregnated with a peculiar empyreumatic
odour, which oil can be very usefully employed in oiling machinery, lighting,
&c.; second, a residue which, when warm, is liquid, and when cold is solid,
and which is designated by the name of pitch, and is very combustible, and
slightly resembling, by its brightness, bitumen of Indea. The problem to
resolve is to effect in the best way the separation of these two products.
Distillation by the ordinary processes presents great inconveniences taking
place under the influence of the pressure of the atmosphere. It is necessary
to raise the temperature to a very high degree, when an important quantity of
the essential oil is decomposed, the empyreumatic odour is acquired, and the
expence of fuel is much increased. The means of condensation being imper-
fect, a considerable loss of oil is experienced, and the oil in volatilising carries
with it foreign matters, which it would be important to separate by washing,
which is not now done. The following mode remedies effectually those incon-
veniences: The tar is introduced by an opening (a, Figures 1 and 2),
Sheet III., into a boiler similar to those used for steam engines; it is filled
to about half full, or at most two thirds; a cock closes the opening (a).
When, by the action of the furnace, the tar is at the point of ebullition, a jet
of steam is introduced into the boiler by a tube (b, b), which is closed by a
cock fitted to it for that purpose. The two extremities of the tube (b, b,)
ending in knobs pierced with holes like the rose of a watering pot, dip into
the tar. The effect of this steam is to produce an ebullition which aids the

page_text: evaporation of the oil. By this means any sudden increase of the heat is
avoided which otherwise would quickly injure the oil, and decompose a part of
it. The vapours of the oil and of the water are led by the pipes C, C¹, C",
into the condensor D, D, which is carefully closed. This pipe crosses the box
or vessel E, E, filled with running water. It is here that the condensation of
the vapours commences. The small quantity condensed in the rising tube c, c,
is collected by means of a raised edge or gutter, and reconducted to the con-
densor by a small inclined tube. An air pump is placed upon the condensor,
or communicates with it. It commences by withdrawing the air from the
apparatus, and creating a vacuum. Its action should be continued, although
gently, in order to maintain the vacuum, by withdrawing the air which is dis-
engaged by the ebullition of the matters in course of distillation and the air
introduced by the steam. The vapours which are not condensed in the pipe
before coming into the condensor are there completely condensed by the
influence of a jet of cold water rising by the tube F, F, to G, as an effect of
the vacuum. The water and the oil run to the bottom of the condensor, and
there arrange themselves according to their specific gravity, the oil being
uppermost, the water having traversed, in the form of a shower, the column of
oil, which is cooled and thoroughly washed by it in its passage. The con-
densed water, as well as that brought by the tube F, F, to effect the condensa-
tion, return into a cistern by the tube H, H, which should be sufficiently long
to enable the water to descend, notwithstanding the effect of the vacuum. The
completion of the operation is known by gathering, by means of a glass globe
applied at V, and emptied of air, a small quantity of the vapour entering the
condensor. If there is nothing but water the operation is finished. The
cocks of the tubes (b, b,) F, F, H, H, are then closed, and the cocks I and a
are opened, and the air enters into the apparatus, and the pitch flows out
and runs into vessels or on to plates placed for its reception. The present
moment is taken advantage of to collect the oil by opening the cock L. The
level is indicated in the condensor by a guage. We have supposed in
beginning, that the tubes F, F, H, H, were full of water before creating the
vacuum. It is easy to obtain this condition. As soon as one operation is
finished, another can be immediately commenced. This system offers many
advantages. The distillation taking place in a vacuum, the temperature
necessary for evaporation is much lower, and the result is a saving of fuel,
and less time is occupied in the operation. The oil obtained is of better
quality, with less colour and less smell than that obtained in the ordinary way.
By this arrangement of the condensor the condensation is as perfect as
possible; no loss of the vapour of the oil can take place. The washing of the

page_text: oil taking place as fast as it is condensed, the foreign matters are separated
from it, and it is consequently of a great purity, which will admit of its being
used in many cases in which it would otherwise be inapplicable. The above-
described method of distilling tar is also applicable to the distillation of naphtha
and other products from coal.
FOURTH PROCESS.-ARTIFICIAL FUEL.
Mode of forming small coal into blocks.-The considerable difference in
value between coal in large fragments and small coal had long since suggested
the idea of uniting or cementing together artificially. small coal, in order to
endow it with the same properties and the same advantages which coal in
large blocks possesses. After many trials this important result has been
obtained in Russia, England, and France, by the use of tar or of the pitch
remaining after the distillation of tar as a cement. This fact is now well
known, but it left still the important problem to be resolved of the best mode
of executing this combination, for the process hitherto adopted left much to be
desired. The mode of combination consists in uniting in a hot state small
coal with a certain proportion of pitch, or else in a cold state with tar, and
submitting the mass which has been run into moulds to great pressure before
the cooling, which completes the combination when pitch is employed, or
before placing the fuel in the drying stove, which volatilises the essential oil
when tar is used. The difference of the systems consist only in the mode of
application. The improved apparatus is represented in Sheet IV.
Figure 1 is a plan, and Figure 2 a vertical section. It is composed of two
principal parts, the mixer, which serves to work together the hot mixture of
pitch and small coal, and the compressor, which gives the form of bricks to the
mixture in subjecting it to a great pressure. The mixer is a large cylinder
provided with two openings, one, A, at the upper end, for the introduction of
the materials, and the other, B, at the lower end for withdrawing them. This
large cylinder contains in its interior and concentric with it a cylinder of a
less diameter, C, C¹, slightly contracted at its two extremities in such a manner
that its form would be rather that of two cones joined together at their bases.
The under part is closed by a grating, whilst the upper part is open. This
interior cylinder serves as a furnace for heating the matters introduced intro-
duced into the large cylinder; it receives from the motive power a rotary
motion by the cog wheel D, D', fixed at the upper part. To the heating or
inner cylinder several arms are fixed in such a manner as to scrape the interior
of the large cylinder by the rotary motion of the heating cylinders. Other
arms made of iron are likewise fixed in the interior circumference of the large

page_text: cylinder in such a manner that, although fixed, they scrape the heating
cylinder when it is put in motion. By this arrangement the matter cannot
attach itself to any part of the sides of the apparatus, and will be perfectly
mixed. Small coal mixed with about six or eight per cent. of crushed pitch
is introduced by the opening A, and care must be taken at the same time to
keep the heating cylinder constantly filled with coal or with small coke.
Under the influence of heat developed by the heating cylinder the pitch
becomes melted, and its liquidation will be complete before it has reached the
lower part of the apparatus. The agitation of the arms by the rotary move-
ment communicated to the heating cylinder mixes the coal as intimately as
possible with the melted pitch. The arms are slightly bevilled, so as to give
the mixture a tendency to descend. The combination being. then of the con-
sistence of rather thick mortar, issues by the opening B and fills the moulds,
which give to the above combination a shape somewhat resembling bricks, and
which are hereafter described. But first, it is necessary to describe the mode
of heating the inner or heating cylinder.
The fuel is supplied to the furnace from above, and this opening may remain
free for the admission of air; and air may also be supplied by the opening in
the lower part. The current of gas from the combustion will descend the full
length of the heating cylinder. The products of combustion will fill the space E,
making a circuit under the base of the great cylinder, and pass into the flue
F, F, contained between the outer casing of masonry and the great cylinder
itself. After having traversed this space in a spiral direction, the gases
generated by the combustion having lost the greater part of their heat, escape
into the chimney G. It will thus be seen that the mixing apparatus is heated
within and without, that is, in the best possible manner. The matter having
been properly prepared, issues from the apparatus by the opening B, and is
received in the brick moulds. These moulds are disposed upon a large
circular ring attached by cross arms to a vertical shaft placed in the centre so
that the ring is capable of turning on its axis. The outer edge of this ring
carries teeth, into which gears a pinion P, fixed in the same shaft, which.com-
municates the movement to the heating cylinder. Each of the moulds is
closed at its under part by a moveable bottom H rising or falling like a piston.
The lower end or shank of this piston is provided with a roller I, moving
upon a circular railway placed below the middle of the ring. Two rollers
K, K', moving in grooves fixed to the ring, keep the shank of the piston in a
vertical position: In this situation each mould in passing under the opening
B of the mixer is filled with matter, the piston forming the bottom being then
in its lowest position. The ring in turning carries along the pistons in its slow
movement, but, arrived at a certain distance, it encounters the compressing

page_text: apparatus, represented in action by the Figures 3 and 4; Figure 3 is a section
through the line Y, Z, in Figure 1, and Figure 4 is a section through the arc
V, X, in Figure 1. The 'cast-iron plates L; L, bound together by chains and
furnished with rollers moving upon two endless arcs or supports placed above
the ring, and maintained by means of a solid cast-iron support, form a species
of endless band or chain. Two of these plates can at the same time rest upon
the orifice of the moulds filled with matter, and are kept there by the aid of
small hooks or pegs, which enter into corresponding holes provided in the ring.
The ring by its motion carries with it these plates, which place themselves in
succession upon the orifice of each mould, and detach themselves after passing
a certain distance to rise over the top of the support, and again to return.
When a plate rests upon the orifice of a mould, the corresponding bottom of
this mould or piston H resting by its lower roller I upon the circular railway,
meets an inclined plane M, M', which obliges it to ascend, by which a pressure
is given to the matter contained in the mould between the covering plate L
and the piston H. This pressure is regulated at will by the height of the
inclined plane. When the roller of the piston has arrived at the top of the
inclined plane it comes upon a horizontal part N, N¹, when the pressure
ceases; at the same time the covering plate having no longer to sustain the
pressure, is raised, and in its turn returns to repeat the same process. In
order to remove the bricks from the moulds it is only necessary to cause the
piston H to be raised upon a second inclined plane O, O'; the brick is then
upon a level with the ring, and can be removed to a table T, Figure 1, by
means of a plank placed obliquely, or may be removed by the workmen to
be placed in the storehouse. The piston is brought to its original position
before reaching the mixer by causing it to descend an inclined plane, whose
height is equal to the sum of the two ascending inclined planes. A jet of
water placed above the ring may flow upon the bricks in order to hasten their
cooling. From this description it is seen that a single transmission of motion
suffices for the whole apparatus, as well for the mixer as for the formation of
the bricks, the compression of them, and removing them from the moulds;
the whole work is entirely mechanical. To carry on a manufactory of the
article on a large scale but few workmen are required, sufficient to supply the
apparatus, maintain the fire, and remove the bricks, which are then ready for
the market. The operation is carried on in all its parts without stopping
for the compression, and the mixing is executed in a close vessel without loss
of time, of heat, or of the essential oil of the coal. The whole is completed
in the most economical manner, and under the best conditions for the quality
of the product.
Having thus described the nature of the Invention, and the manner in

page_text: which the same is to be performed, I wish it to be understood that I do not
confine myself to the precise details, so long as the peculiar character of either
part of the Invention be retained; but I claim,-
Firstly, the purification or separation of coal from foreign matters by taking
advantage of the difference of their specific gravities, as above described.
Secondly, I claim the classification of coal according to size when used in
combination with the process of water sifting, as above described.
Thirdly, I claim the combination of the continuously acting, classifying, and
water-sifting apparatus for the separation from each other of substances
differing in specific gravity, as above described.
Fourthly, I claim the general form and construction of coke ovens, as above
described.
Fifthly, I claim the use of a moveable arch or cover for a coke oven, as
above described.
Sixthly, I claim the method of obtaining coke of great density by ramming
the coal after it is introduced into the oven, as above described.
Seventhly, I claim the mode of discharging coke ovens by means of the
moveable discharging apparatus, capable of being readily attached to either of
several coke ovens, as above described.
Eighthly, I claim the mode of extinguishing the coke by passing it from the
oven into a close box or extinguishing vessel, as above described.
Ninthly, I claim the method of coking coal in ovens by alternating currents
passing through passages formed in the mass of the coal itself, as above
described:
Tenthly, I claim the method of collecting the superfluous tar and ammoniacal
liquor, as above described.
Eleventhly, I claim the method of distilling tar by the introduction of steam
and the partial removal of the pressure of the atmosphere, and the condensing
and washing the products by the introduction of water into the condenser, as
above described.
And I also claim this process when applied to the distillation and purifica-
tion of naphtha or other products from coal.
Twelfthly,. I claim, as an improvement in the manufacture of artificial
fuel, the arrangement and construction of the mixer and compresser, as above
described.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Twenty-ninth day of April, in the year of our Lord
One thousand eight hundred and fifty.
CHARLES (L.s.) COWPER.

page_text: AND BE IT REMEMBERED, that on the Twenty-ninth day of April, in
the year of our Lord 1850, the aforesaid Charles Cowper came before our said
Lady the Queen in Her Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained and specified, in form above
written. And also the Specification aforesaid was stamped according to the.
tenor of the Statute made for that purpose.
Enrolled the Twenty-ninth day of April, in the year of our Lord One
thousand eight hundred and fifty