IMPROVEMENTS IN THE TREATMENT OF COAL, AND IN THE PURIFICATION, DESICCATION, AND AGGLOMERATION OF COAL, AND IN MACHINERY AND APPARATUS FOR SUCH PURPOSES
Year: 1856

page_text: LETTERS PATENT to Charles Cowper, of No. 20, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE TREATMENT OF COAL, AND IN THE PURIFICATION,
DESICCATION, AND AGGLOMERATION OF COAL, AND IN MACHINERY AND APPARATUS
FOR SUCH PURPOSES."-A communication.
PROVISIONAL SPECIFICATION left by the said Charles Cowper at the
Office of the Commissioners of Patents, with his Petition, on the
26th May 1856.
I, CHARLES COWPER, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE TREATMENT OF COAL, AND IN THE PURIFICATION, DESIC-
CATION, AND AGGLOMERATION OF COAL, AND IN MACHINERY AND APPARATUS FOR SUCH
PURPOSES," to be as follows:-
The Invention relates to improvements in separating coal from pyrites,
schist, and other substances by the action of water, and in drying the coal
and converting it into artificial fuel, or agglomerating it with the assistanco
of heat, and in apparatus for such purposes.
I construct apparatus on the same principle as that described in the
Specification of certain Letters Patent granted to me, and bearing date at
Westminster, the Second day of November 1849, with various modifications
adapted for the treatment of different qualities and species of coal. In the

page_text: apparatus described in the aforesaid Letters Patent the coal is separated or
classified by sieves or perforated plates into several sizes, which are separately
purified in a water-sifting apparatus, consisting generally of a vessel or chest
filled with water, and having a perforated plate or shelf on which the coal is
placed, while a rapid up and down current of water is driven through the
plate by means of a piston working in a cylinder or case. The pyrites and
schist, being specifically heavier than the coal, pass under a partition, and fall
into the lower part of the chest, while the coal passes over the partition and
slides down an inclined grating, through which the water drains away from it.
In lieu of this arrangement, I cause the coal to be carried by a current of
water, or by the action of the water-sifting apparatus, into another vessel or
compartment containing water, from which it is raised up an inclined plane
by means of an endless chain of paddles. The water thus drains out of the
coal as it ascends, and it is delivered into waggons or other receptacles at
the top of the inclined plane. The water which drains from it runs back
again into the vessel, and passes into an adjoining compartment, whence it
overflows through a wide opening or weir, so that the motion of the water
is very slow, and very little coal or dust is carried away by it. When the
coal contains argillaceous matter it is washed by a supply of water in the
form of rain, which is allowed to fall upon it as it is carried up by the endless
chain or elevator. In some cases, as when the dust of the coal is very
impure, the coal is passed over a perforated plate or metallic cloth to allow
a portion of the dust to escape. When, on the contrary, the dust is nearly
pure (as frequently happens with coal of a friable nature), the outlet or weir
for the escape of the water is closed or suppressed, and the same water is
constantly used, with the addition of a small quantity to compensate for that
carried away by the wet coal. The coal is then completely submerged as it
travels over into the second vessel until it is raised by the endless chain or
elevator. When the water which passes away from the apparatus is to be
used again, it is clarified by causing it to flow through a vessel divided into
a series of compartments in which the dust and impurities are deposited.
The water flows over each partition in a thin sheet with a very moderate
velocity. When a certain quantity has collected, the stream is diverted into
another similar vessel, while the first is emptied through sluices or otherwise.
The water-sifting apparatus is made with a deep vessel or well beneath it
for the reception of the muddy deposits which are evacuated from time to
time through a sluico at the lower part. This well is prolonged under the
cylinder, for which it forms the foundation, and its side which is opposed to
the cylinder is inclined. The whole is fixed with frames firmly imbedded in

page_text: masonry. The crank shaft which drives the pistons is supported by frames
cast with or firmly secured to the cylinders and chests and to each other, so
as to render the whole apparatus as firm and solid as possible, to resist the
vibration caused by the rapid movement of the pistons. The pistons are
solid, and a supply of water is introduced into the apparatus when required
by a double-acting horizontal pump of variable stroke, and regulated by cocks
or valves.
In some cases it is required to break up the large fragments of coal
before purifying them, which is effected in the following manner :-The coal
is conveyed on to a series of perforated plates or sieves places in stages in
a frame, which is suspended and acted upon by a cam, so as to produce a
succession of blows or strokes. The largest fragments fall upon a table, where
a workman picks out the large stones or foreign matters, the remainder is
thrown between a pair of crushing rollers by which it is reduced to fragments,
which pass (together with the coal which has passed through the first sieve
and been retained by the second sieve) through a second pair of rollers
placed closer together than the first pair. The crushed coal is mixed with
that which has passed through the second sieve, and the whole is then con-
veyed to the purifying apparatus above mentioned. The crushing rollers may
be plain or grooved in one or both directions. Each crushing roller may be
driven by a separate wheel and pinion, and one of them is made adjustable
and is pressed towards the other by screws or springs or otherwise. When
the coal is all reduced to a tolerably uniform degree of fineness, the purifying
operation may be performed in a single purifying or water-sifting vessel. A
convenient apparatus for this purpose is constructed, with a steam engine
mounted on the apparatus itself, and driving direct to the crank shaft, from
which the various motions are communicated to the elevators, pumps, sieves,
and other parts of the apparatus. The coal is thrown into a hopper, which
conducts it on to the first of two sieves worked by a cam. The fragments
which are stopped by the first sieve fall upon a table or grating, where the
large stones and foreign matters are picked out by hand. The large lumps
of coal may be placed aside for separate use, or they may be broken up on the
grating through which the fragments fall between two crushing rollers, which
also receive the fragments which have passed through the first sieve and been
arrested by the second sieve. The coal crushed by the rollers is mixed with
that which has passed the second sieve, and the whole is conveyed by an
elevator to the water-sifting apparatus, connected with a vessel having an
inclined plane and endless chain of paddles, as before. The partition between
the two vessels being below the surface of the water, the coal is gradually

page_text: carried over the partition and removed by the endless chain. The pyrites and
schist are carried by the action of the piston (assisted, if necessary, by
inclining the perforated plate) in the opposite direction, and pass under one
and then over another adjustable partition or sluice, and fall into a receptacle,
from the end of which they are removed. A very small supply of water is
required for this apparatus. In some cases, however, as, for instance, when
the coal contains clay or argillaceous matter, it is advantageous to renew the
water more rapidly. In this case an overflow aperture or weir is provided,
and a supply of water is introduced by a pump. The water which overflows
is clarified by subsidence and employed again. The pump may be driven by
a prolongation of the piston rod of the steam engine. A smaller water-sifting
apparatus, which may be worked either by hand or by steam, is constructed
with a moveable sieve or perforated plate, which is fitted into one compart-
ment of a vessel or chest, which is divided by a partition. The sieve is
worked up and down rapidly by means of a lever worked by hand, or by
a steam cylinder and piston, or otherwise. The pyrites and schist collect upon
the perforated plate, while the purified coal travels over the partition into the
second compartment, where it is received in a perforated receptacle through
which the water passes, and returns through a valvo to the lower part of the
first compartment. The coal is removed by hand or by the elevator, as
before. This apparatus may also be constructed without the valve and the
perforated receptacle, the water being allowed to pass between the sieves and
the sides of the compartment in which it works. The coal on leaving this
apparatus retains about twelve per cent., more or less, of water; and for many
purposes it is desirable or necessary to obtain it in a dry state, or nearly so.
About half this water may be removed by allowing it to drain for a day or
two, after which the loss of water is very slow. The cost of placing the coal
in heaps and afterwards removing it by manual labour would, however, be so
great as to materially enhance the cost of the coal. The drying is effected by
machinery in the following manner:-The coal is carried up by the elevator
or endless chain of paddles herein-before mentioned, and delivered on the
centre of a horizontal endless web, which is capable of travelling in either
direction. This web is placed above two large bins or chambers with inclined
sides, into which it distributes the coal. The coal coming from the purifying
machine during one day's work is distributed in one bin, and the endless
web is reversed, so as to distribute the next day's work in the other
bin. A considerable portion of water drains away from the coal in these
bius, which have openings for its escape. The coal is then allowed to
fall upon another endless web placed below the bins, which conveys it to

page_text: the foot of a long inclined or horizontal semi-cylindrical trough, in which
works a long flat-threaded screw. The coal is thus gradually carried up the
trough and delivered at its upper end into waggons or a receptacle provided
for it. The trough has a doublo bottom, through which a current of hot gas
or air is conveyed for the purpose of drying the coal. A number of slits or
perforations are made in the trough to allow the hot air to pass through the
coal. When a source of heat, such as a coke oven, is near the apparatus, its
heat may be employed for heating air for drying the coal, or the products of
combustion may be at once conducted into the double bottom of the trough,
or a fan driven by a steam engine is employed to supply air to the fire of the
steam boiler, and the products of combustion are passed into the doublo
bottom of the trough. When the temperature of the products of combustion
is injuriously high, a portion of cold air from the fan is mixed with them. A
flue is also provided for conveying the products of combustion direct to tho
trough in lieu of passing under the boiler. All the flucs or passages are pro-
vided with suitable valves or registers, so that the production of steam in the
boiler, and the temperature of the air passing up the trough, are completely
under control. The coal thus dried, and while still warm, may be at once agglo-
merated or converted into artificial fuel. For this purpose it is allowed to
fall into a hopper, where it meets with thin streams of cold or hot tar, and the
mixture passes down an inclined or vertical cylindrical pipe or retort containing
a revolving screw or spiral. Or a retort is used of a form similar to that of
several pipes placed side by side, and communicating together, and having
s crew in the axis of each pipe. The materials are thus prevented from
adhering to the sides of the retort, which is heated by a fire. The pasty
mixture issues from the lower end of the retort, and passes between grooved
or plain rollers, by which it is compressed and driven through a spout or die
on to a table or series of rollers, where it is cut into convenient lengths.
Spring blades press against the surface of the rollers to prevent the escape
of the material. Or the rollers are made with deep grooves of the form of
the prisms or blocks of fuel to be produced, and they are made to dip into
water, or water is passed through them to cool them, to prevent the adhesion
of the materials. The blocks of fuel may be allowed to fall into water, or
they may fall upon an endless web, which conveys them away. The ends of
the blocks or prisms may be compressed by mandrils or plungers entering the
grooves of the rollers. After this compression one mandril retires and the
other continues to advance a little, so as to detach the block from the rollers.
By this Invention inferior descriptions of coal containing large quantities of
pyrites and other impurities may be classified, purified, dried, and converted

page_text: into an artificial fuel of great purity, and at a comparatively trifling expense,
as the various processes are performed by the machinery herein-before
described with very little manual labour.
4
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Cowper in the Great Seal Patent Office on the
26th November 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
COWDER, of No. 20, Southampton Buildings, Chancery Lane, in the County
of Middlesex, send greeting.
WHEREAS IIer most Excellent Majesty Queen Victoria, by Ior Letters
Patent, bearing date the Twenty-sixth day of May, in the year of our Lord
One thousand eight hundred and fifty-six, in the nineteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Charles Cowper, Her special licence that I, the said Charles Cowper, my
executors, administrators, and assigns, or such others as I, the said Charles
Cowper, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN THE TREATMENT
OF COAL, AND IN THE PURIFICATION, DESICCATION, AND AGGLOMERATION OF COAL, AND
IN MACHINERY AND APPARATUS FOR SUCH PURPOSES," upon the condition (amongst
others) that I, the said Charles Cowper, my executors or administrators, by
an instrument in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same to
be filed in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Cowper, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement.
thereof, reference being had to the accompanying Drawings, and to the figures
and letters marked thereon, that is to say:-
The Invention relates to improvements in separating coal from pyrites,
schist, and other substances by the action of water, and in drying the coal and

page_text: converting it into artificial fuel, or agglomerating it with the assistance of heat,
and in apparatus for such purposes. The apparatus for and mode of separating
the coal from foreign matters are generally similar to those described in the
Specifications of certain former Letters Patent granted to me, and bearing
date respectively at Westminster, the Second day of November, in the year of
our Lord One thousand eight hundred and forty-nine, and at Edinburgh, tho
Twenty-sixth day of April, in the year of our Lord One thousand eight
hundred and fifty, and certain other Letters Patent, bearing date at West-
minster, the Eighth day of December, in the year of our Lord One thousand
eight hundred and fifty-one. In the apparatus described in the aforesaid
Specifications, the coal is separated or classified by sieves or perforated plates
into several different sizes, each of which is separately purified in a water-
sifting apparatus, consisting generally of a vessel or chest containing water,
and having a perforated plate or shelf on which the coal is placed, while a
rapid up and down current of water is driven through the plate by means of
a piston working in a cylinder or case. The pyrites and schist, being specifi-
cally heavier than the coal, pass under a partition, and fall into the lower part
of the chest, while the coal passes over the partition and slides down an
inclined grating, through which the water drains away from it.
By the present Invention certain modifications, alterations, and additions are
introduced in this apparatus to render it more advantageously applicable to
the purification of different descriptions of coal, and generally to increase
its efficiency, and to adapt it for the purification of small as well as large
quantities of coal..
.
Sheets I. and II. of the accompanying Drawings represent a large apparatus
with three purifying chests. Figure 1 is a vertical section, and Figure 2 is a
plan of the apparatus. In this apparatus the purified coal is separated from
the water by raising it out of the water by means of an endles chain of paddles
or buckets, in lieu of separating the water by filtration through perforated
plates, or gratings, or metallic cloth. In some cases also the coal is carried
from the purifying or water-sifting compartment into that in which the endless
chain works by the action of the piston of the water-sifting apparatus, instead
of by means of a current of water acting at the surface. This arrangement is
advantageously applicable to friable coals containing a good deal of dust.
The coal is passed through a pair of crushing rollers A, and falls into a bin or
compartment B, from which it passes through an opening, regulated by a
sliding door, into the compartment C, whence it is raised by an endless chain
of buckets or elevator D, which delivers it to the sieves E, by which it is
classified into three different sizes, which fall into the three water-sifting chests

page_text: F, F, F. These chests are provided with perforated plates, one of which is
shewn at G in Figure 1, and with cylinders II, II, II³, and pistons I', I², I³.
The pistons receive a rapid up and down motion from the cranked shaft J.
The purified coal falls from the purifying chests into a vessel or chamber
divided into two compartments K and L by a partition a, b. In the compart-
mont K is placed an endless chain of paddles or buckets M, which raises the
coal up the incline c, d, and delivers it at d into waggons, or into a draining
apparatus, in which the water drains away from it, as herein-after described.
The greater part of the water drains away from the coal as it ascends the
incline c, d, and the particles of coal which are carried down by the water are
again taken up by the following buckets, so that a species of filtration is
effected through the coal itself as it ascends the incline. In lieu of the endless
chain of paddles, a helical blade or screw, working in a semi-cylindrical trough,
may be employed, similar to that hereiu-after described in reference to
Sheet V.
The water passes through the longitudinal opening under the partition into
the compartment L, and flows in a thin sheet over the partition i into the
trough N, which conducts it to the clarifying vessels herein-after described.
The overflow partition i extends the whole length of the purifying chests, so
that the ascending velocity of the water in the compartment L is very slight,
and none of the coal is carried away by it except those particles which are
sufficiently fine to be held in suspension by the water. The heavier portions
settle to the bottom of the vessel, and aro carried away by the endless chain of
buckets. The coal is thus almost entirely collected and removed from the
water.
.
In some cases when the coal is mixed with a good deal of clay, it is
advantageous to cause a shower of water to fall upon the endless chain, so as
to wash away the muddy deposit which would otherwise soil the surface of the
coal. If the powder is very sulphurous or impure, a portion of it may be
allowed to escape through a grating or perforated plate at e, f, provided with a
gutter, which conveys the muddy water into the trough N. When the powder
is naturally nearly purc, as is generally or frequently the case with friable coals,
it is important to collect the whole of it with care. In this case the partition
a, b, is removed, and the ends of the compartments K and I are closed, so as
to form one single compartment. The trough N is removed, and the transfer
of the coal from the water-sifting vessel into the compartment K, L, is effected
by the action of the piston. The water-sifting vessels and the compartment
K, L, are filled with water up to the dotted line g, h, so that the coal may be
completely immersed. A very small quantity of water is then required to

page_text: supply the place of that which is carried away by the wet coal, and a small
portion which escapes at an overflow passage at the level g, h. The schist and
pyrites pass under the partition V, and over the partition V', into a chamber U,
whence they pass out at a sluice t, shewn by dotted lines in Figure 1.
When the transfer of the coal is effected by the water passing over the
partition, as first herein-before described, the water which escapes at tho
trough N requires to be clarified to a certain extent before being returned to
the apparatus to be used repeatedly. For this purpose it is conducted into a
double series of vessels, so arranged that the water flows from the surface of
cach vessel into the next in a very thin and wide sheet, so that the velocity of
the current may be as small as possible. The deposit which subsides in cach
vessel or compartment can be withdrawn by means of doors or sluices at the
lower part. When one series of vessels is filled with the carbonaceous deposit,
it is emptied, while the current of water is diverted into the other series of
vessels which have been previously emptied, and so on alternately.
There are several points in the construction of the apparatus shewn in
Sheets I. and II. which require to be noticed. The chambers O below the
perforated plates G are made of considerable depth, for receiving the muddy
deposit, which is discharged by sliding doors or sluices P. The opposite side
The
of the chamber is inclined towards the sluice P, as shown in Figure 1.
chambers are extended below the cylinders H', II, II³, so as to form a base
for them, and to give greater stability to the apparatus. They are also pro-
vided with frames, shewn in Figure 1 by dotted lines, and bedded in the
masonry Q. The cranked shaft J is carried by frames R, R, bolted to lugs or
brackets cast upon the cylinders and chests. The frames are connected by
cross frames or rods, which also serve to carry lovers for giving a variable or
differential motion to the pistons when required. In Figure 1 the connecting
rod is jointed at one end to the cranked shaft, and at the other end to the
piston. When, however, a differential motion is required, the crank may be
made to work in a slot in a lever, to which the upper end of the connecting
rod is connected. The piston may thus be made to move with different
velocities in its up and down strokes, and its length of stroke may be varied
by connecting the connecting rod to the aforesaid lever at different distances
from its fulcrum. The pistons are made solid. A supply of water is intro-
duced into the cylinders, or any other part of the chests, by pipes leading
from a horizontal double-acting pump, shewn at S, in Figure 2, and which is
driven by a crank on the main shaft T. The pin of the crank is adjustable,
or the pump is otherwise so arranged as to admit of its length of stroke being
varied

page_text: Figure 3, Sheet III., is a section, and Figure 4 is a plan, of a machine for
crushing the large fragments of coal when required. The coal is thrown into
a hopper T, whence it falls on a jogging sieve A, B, formed of gratings on
perforated plates, by which the coal is separated or classified into a number of
different sizes, exceeding by one the number of perforated plates or gratings.
This jogging sieve is suspended by inclined rods a, a, and is pushed forwards
by a cam b, on a revolving shaft, acting against a projection c on the sieve
As the cam passes the projection c, the sieve falls back against fixed stops
and the jogging motion thus produced facilitates the descent of the coal. The
larger fragments fall upon the table C, D, where a workman picks out the
Jarge stones or foreign matters. The remainder is thrown between the first
or upper pair of crushing rollers E, F, from which it falls between the second
or lower pair of rollers G, II, which are placed closer together than the first
pair. The coal falls from the second pair of rollers into a bin or chamber,
whence it is raised by the elevator, as herein-before described. . The coal and
other matters which pass through the first perforated plate or grating, and are
stopped by the second grating, are conveyed at once to the second pair of
rollers, and the coal and other matters which are small enough to pass through
the second grating are received on a solid plate, which delivers them directly
into the bin. The coal and other matters in the bin are then raised by the
clevator, and supplied to the purifying apparatus, as herein-before described.
One roller E and G. of each pair it mounted in moveable bearings, and is
pressed towards the other roller by a spring or springs I, J, which may bo
made of steel, or caoutchouc, or other suitable material. It is prevented from
approaching too close to the other roller by adjusting screws. Thus, in the
event of a large stone or other hard substance entering between the rollers,
the moveable one yields a little, and the machine is not broken. Each roller
is driven by a pulley or wheel, independently of the other roller of the pair.
E', F, G, H, are the pullies which are connected respectively to the rollers
E, F, G, H. Three or more pairs of rollers may be applied in an apparatus
constructed in a similar manner, and having a corresponding number of sieves
or perforated plates. In general, however, the two pairs of crushing rollers
are sufficient.
I will now proceed to describe another apparatus, which may be called a
portable apparatus, as it admits of being more readily moved from place to
place than the large apparatus herein-before described.
Figure 5, Sheet IV., is a vertical section, and Figure 6 is a plan of the
portable apparatus. It is constructed with a single purifying chest F, and
the steam engine S which drives it is mounted on and forms part of the

page_text: machine itself, together with the pump which supplies the purifying chest and
another supplementary or extra pump. The steam engine S drives directly
the cranked shaft J, which works the piston I of the purifying chest, and which
shaft is the main shaft from which the different parts of the apparatus are
driven. The jogging sieves, the crushing rollers, the elevator, and the endless
chain of paddles are driven by straps passing round pulleys on the main shaft,
which carries a small fly wheel for equalizing its motion. The coal is brought
by waggons or barrows or otherwise along the rails or platform A, and thrown
into the hopper B, whence it falls on the jogging sieves C. The lumps
exceeding about two and a half or three inches diameter, according to the
nature of the coal, not being able to pass through the first grating d, d, fall
upon the table or grate E, where a workman picks out the large stones
and foreign matters. The large lumps of coal may be removed and put aside,
or they may be broken by a hammer upon the grate E, through which the
fragments fall between the crushing rollers, where they are reduced to
fragments of the size required for the operation. The portion of coal which
has passed through the first grating or perforated plate d, d, and been arrested
by the second grating f,f, of the jogging sieve, is also conveyed between the
crushing rollers. The fine portion of the coal which has passed through
the second grating f, f, is arrested by the solid plate or bottom g, g, and con-
veyed directly into the bin or receptacle, from which it is raised by the elevator.
This apparatus may be constructed with an additional pair or pairs of crushing
rollers, arranged in a similar manner, and supplied by additional sieves or
perforated plates. The coal raised by the buckets of the elevator D is shot
or delivered at once into the purifying chest F by means of a trough or shoot
i, i. The action of the piston I of the purifying chest causes the coal and the
foreign matters to be classified in the order of their specific gravities. The
coal is thus brought to the surface, while the schist and pyrites descend to the
bottom and lie on the perforated plate G, G'. But the action of the piston has
also the effect of constantly levelling the surface of the matters in the chest,
provided that they are totally immersed. The chest being filled with water to
the level k, k, and the side 7, 1, being at a lower level, it follows that the purified
coal is continually carried over or transferred from the purifying chest into the
chamber or compartment K as fast as the fresh coal enters the purifying chest.
As the fresh coal enters at i, while the purified coal escapes at 7, the coal is
submitted in its passago to the classifying action of the piston, which separates
the matters in the order of their density. By this arrangement the action of
the piston not only classifies the matters according to their specific gravity,
but it also effects the transfer or delivery of the purified coal, which in some

page_text: of the other arrangements is effected by the overflow or current of the water.
When the transfer is effected by the flow of the water a large quantity of
water is required, and a considerable quantity of dust is carried off by it. This
dust is slow in subsiding and difficult to collect. On the other hand, by causing
the transfer to be effected by the action of the piston, a very small quantity
of water is sufficient, and the quantity may even be reduced to that which
is absorbed by the coal, by having no overflow of the water, and consequently
no loss of dust. There are, however, cases in which the argillaceous nature of
the coal requires a more frequent renewal of the water; an overflow passago
is then made at n, n, in the side of the vessel. The excess of water then passes
away, and may be conducted into depositing or clarifying vessels, as herein-
before described, and again returned into the apparatus by the pump. This
pump delivers the water directly into the purifying chest by the pipe o, and is
driven by a prolongation of the piston rod of the steam engine S. A cock p
serves to regulate the quantity introduced. The feed pump for supplying the
steam boiler may be fixed by the side of this pump. The purified coal falling
into the chamber K is raised by the endless chain of paddles M, which delivers
it into waggons or into a draining apparatus, as in the machine shewn in
Sheets I. and II. The schist and pyrites accumulate on the perforated plato
G, G¹, and are carried towards the side G by the action of the piston, assisted,
if necessary, by inclining the perforated plate. They pass under the partition
or sluico V, and over the partition or sluice V₁, into the chamber U, from
whence they are easily removed into waggons by opening a sluice t, shewn by
dotted lines in Figure 5. This sluice is opened from time to time and the
schist discharged, without stopping the action of the machine. The muddy
deposit which accumulates in the chamber O of the purifying vessel, is also
discharged without stopping the machine, by opening the sluice P. This
apparatus is easily removed from place to place, being mounted on a frame,
and easily erected, and carrying its own steam engine and pumps, and driving
directly the crushing rollers and elevator.
This new method of transferring the coal by the action of the piston is also
applicable to apparatus in which the coal is placed in a jigging sieve, which is
agitated up and down in water, as shewn in Figures 7, 8, and 8 bis, Sheet V.
Figure 7 is a vertical longitudinal section, and Figure 8 is a plan, and
Figure 8 bis is a transverse section of the apparatus.
: A is the sieve, having a perforated bottom, and capable of being moved up
and down in the compartment Y by means of a lever F, worked by hand
.or by the piston rod of a steam engine, or otherwise. The compartment
Yis separated from another compartment C.by a partition B, over which the

page_text: coal passes into the compartment C. Both compartments Y and C are filled
with water, the level of which is above the partition B. The coal is removed
from the compartment C by hand or by mechanical means, as in the apparatus
herein-before described. The sides D, D, of the compartment C are formed of
perforated plates, through which the water passes into the compartment X.
E is a valve in the partition, which allows the water to return from X into
the compartment Y. The perforated sides D, D, and the valve E may be
dispensed with, and the water allowed to return at the surface by leaving
a sufficient space between the sieve A and the sides of the compartment in
which it works. G is a pipe or trough for supplying the apparatus with water..
When a considerable quantity of schist has accumulated in the sieve A, the
apparatus is stopped, and the schist is removed by hand.
Whatever system of washing or water-sifting may be employed, the coal on
leaving the apparatus is saturated with water, and generally contains about
twelve per cent., more or less, of water. In some cases it is important to dry
the coal more or less completely. This is effected in the following manner :-
It has been found that when the coal is placed in a heap as it comes from
the purifying apparatus, it loses in the first twenty-four or thirty hours about.
six or seven per cent. of water, which drains away from it. After this time
the loss of water is very slow, as the remaining water is retained by capillary
attraction, and but little is lost, although the coal may be left to drain for
a long time; it is necessary therefore to adopt other means for completing the
desiccation. The transport of such large quantities of coal as are obtained
from the purifying machine in twenty-four or thirty hours requires to be.
effected by mechanical means, as the cost of hand labour would be too great
to be profitable.
The desiccation of the purified coal is effected in the following manner :-
Figure 9, Sheet V., is a side view, partly in section, and Figure 10 is a plan,
of a desiccating apparatus connected with a purifying apparatus, constructed
in a similar manner to that shewn in Sheets I. and II.
F, F, F, are the purifying vessels, with their cylinders and pistons as
before; M is the endless chain of paddles, which carries the purified coal up the
incline c, d, and delivers it at pleasure on either of two endless cloths or tables
e, e, or ff, which carry it along and distribute it into two large hopper-shaped
bins or drainers E and E¹. A moveable diagonal board is placed above the
endless table, by means of which the coal is pushed off and falls into the bin
or drainer. The distribution is regulated by adjusting this board. The endless.
chains or tables e, e, and f,f, move in opposite directions, so that when the coal
is directed by a moveable shoot on to the table c, e, it is distributed during the

page_text: whole of one day in the bin E, and on the following day it is distributed in
the bin E by the endless table f.f. While the bin E' is being filled, the coal
placed in E on the previous day has lost about six or seven per cent. of water,
and may then be submitted to the final desiccating operation, which is effected
by the aid of heated air or gases in the following manner:-
At the bottom of the bins or drainers are a number of sluices or sliding
doors, by opening which the coal is allowed to fall upon two endless chains or
tables, similar to those placed above the bins, but moving towards each other
instead of away from each other. The drained coal of the previous day
is carried by one of these collecting endless tables towards the centre of
the apparatus, where it falls into a hopper T, which conducts it into the
desiccating trough U. This trough is of a semi-cylindrical form, and is con-
structed of cast or wrought iron, and provided with a jacket or double bottom
into which heated air or gases are introduced, as herein-after described.
A long slit or series of slits is made in the semi-cylindrical trough, and
covered with perforated plates, with holes sufficiently small to prevent the coal
from passing through while allowing of the passage of the air or gases. The
trough U may be inclined at an angle, as shewn in the Drawing, or placed
horizontally, if preferred. When placed in an inclined position, it serves for
conducting the coal into a receptaclo X, from which it may be readily loaded
into waggons. In the axis of the semi-cylindrical trough U is placed a shaft,
carrying a long helical blade or screw, or series of screws V; the shaft is
carried by bearings supported by cross bars mounted on the sides of the trough,
which is shewn in section on a larger scale in Figure 11. A small portion of
the screw is removed to admit of the passage of the cross bar. The screw is
made to turn upon its axis, and the coal is thus caused to travel along the
trough U, until it falls into the receptacle ✗, which is provided with sliding
doors, through which the coal is allowed to fall into waggons to be carried
away. As the coal travels along the trough U, it is constantly traversed by
the currents of heated air or gases, and stirred and moved about by the motion
of the screw, and it is thus rapidly dried. The quantity and temperature of
the heated air or gases may be so adjusted, that the coal, on arriving at the
end of the trough, may retain about one-half or one per cent. of water, so as to
ensure its not having been heated to an injuriously high temperature. By
increasing the quantity and temperature of the air or gases, the dessication
may be carried still farther, if desired. In lieu of the helical blade or screw,
an endless chain of paddles may be employed, similar to that employed for
raising the coal out of the water, and working in a trough of rectangular or
other suitable form.

page_text: If any source of heat, such as coke ovens or other fires, should be sufficiently
near to the apparatus, they may be employed to heat the air for drying the
coal, or their products of combustion may be conveyed directly into the jacket
of the trough. In many cases, however, no such extraneous source of heat may
be available, and the following arrangement will be found advantageous:-
A centrifugal fan, or other air-blowing machine W, is driven by the steam
engine, and a portion of the air from it is conducted by a pipe n under the
grate or into the furnace of the steam boiler G, which supplies the steam
engine. The products of combustion from this furnace are conducted by a flue
or pipe h, h', directly to the jacket of the trough U, but as their temperature
might often be too high, and their quantity too small, they are mixed with
another portion of air from the fan, conveyed by a branch pipe m into the
pipe h, h, in such proportions that the mixture may have a temperature of
from four hundred to five hundred and fifty degrees, more or less, of Fahren-
heit's thermometer. Registers or valves placed at mand n serve for regulating
the quantities of air which are delivered direct, and which are passed through.
the fire. These valves may be regulated by hand, or by a pyrometer exposed
to the mixture in the pipe leading to the desiccating trough. A part of the heat
produced in the furnace is employed for raising steam for supplying the steam
engine which drives the apparatus, and if there should be an excess of heat for
this purpose, the products of combustion are conveyed directly from the furnace,
by a fluo x, y, into the pipe h, h', instead of previously passing under the
boiler and through the boiler flues to the pipe or fluc h, h', at h. The flue x, y,
is provided with a register or valve for regulating the quantity passing.
through it.
When it is desired to agglomerate the coal, or convert it into blocks of
artificial fuel, it may be advantageously employed in the warm or hot state in
which it issues from the desiccating trough. The fuel may be made of mixtures
of caking or bituminous coal, and non-caking coal, or of mixtures of non-
caking or other coal with pitch or tar. For this purpose, if a simple mixture
of caking and non-caking coal is employed, it is introduced into the hopper A
of the heating apparatus, shewn in Sheet VI. Figure 12 is a vertical section,
and Figure 18 is a plan of the apparatus; Figure 14 is a transverse section
at the line X, Y, in Figure 12. U is a portion of the desiccating trough with
its screw V; A is the hopper which conducts the coal to the retort or heating
vessel B. In sectional form this vessel resembles a series of cylindrical pipes
placed side by side, and communicating laterally with each other, as shewn in
Figure 14. In the axis of each pipe or cylindrical portion is placed a shaft C,

page_text: carrying a helical blade or screw, which is made to revolve by toothed wheels
or otherwise. The vessel B is heated by a furnace D, the products of combus-
tion from which ascend to D', D2, and again descend and escape at the flue L
The coal passes down through the vessel B, where it is heated to a temperature
sufficient to soften the coal, which is prevented from adhering to the vessel B
by the screws which constantly scrape the sides of the vessel. If a mixture of
coal and pitch or tar is employed, the melted pitch or tar is allowed to flow
into the hopper A from a reservoir M, and it is not then necessary to heat the
vessel B to a temperature sufficient for softening the coal itself.
The vessel B may be placed in a vertical or inclined position, and it may be
made of cast iron or wrought iron, or of fire clay, in separate pieces united
together, and with or without lateral apertures for the escape of gases or
vapours evolved during the process. The heating vessel B may be made of
the sectional form shown in Figure 14, with any convenient number of com-
bined cylindrical pipes, or separate cylindrical pipes isolated from each other,
or just touching one another, may be employed.
The hot plastic mass which issues from the vessel or vessels B is moulded
into blocks in the following manner :-If owing to the nature of the coal, and
the purpose for which it is intended, only a moderate degree of compression is
required, it may be obtained by means of two slightly grooved rollers E, F,
turning in opposite directions. The plastic mass from the vessel B is introduced
between the rollers E, F, at B', and is compressed by them into the space G,
from which it issues through dies at G', in the form of continuous prisms,
which are cut transversely into convenient lengths or bricks by means of a
knife. Spring blades H, H, I, K, serve to scrape the rollers and to retain the
materials. These blades may be adjusted by screws. The blades H, H, are
open or perforated in the centre, to allow of the passage of the materials.
When a stronger degree of compression is required, the apparatus shewn in
Figures 15 and 16, Sheet VI., may be employed. Figure 15 is a side view or
clevation, and Figure 16 is a plan of the apparatus. A and A' are two cast-
iron wheels turning towards cach other, and having in their circumferences
deep grooves of an angular or other form, according to the form which it is
required to give to the blocks of artificial fuel. These wheels are driven by
worm wheels B, B, B', B', and right and left handed endless screws at C, C, C¹,C,
on two shafts which carry two toothed wheels D, D', which are driven by a
pinion E. The plastic mass from the heating vessel, herein-before des cribd,
is introduced into a hopper T, the sides of which fit close to the sides of the
wheels A, A'. The mass is siezed by the grooves or cavities of the rollers, and

page_text: compressed by them until it reaches the point of greatest approximation of the
two rollers. As it approaches this point, two sliding plugs F, F, enter the
grooves of the rollers, and compress the mass forcibly at the two ends. These
plugs travel downwards for a short distance with the wheels A, A'. They
advance and forcibly compress the plastic mass, and one of them then recedes,
while the other continues its motion for a short distance, so as to detach the
block from the wheels, and it then recedes.
The sliding plugs F, F, work in sliding plates or blocks, which are moved up
and down by cams or excentrics I, II, on the shafts of the endless screws,
which make one revolution for each block that is moulded. The advancing
motion is given to the plugs by cams I, I, on two shafts K, K, which are driven
at the same speed as the endless screw shafts, by means of toothed wheels
L, L, M, M. Each block of fuel as it is formed falls upon an endless chain
or table, which conveys it to a store-houso or elsewhere. The lower part of
cach wheel dips into water for the purpose of cooling it. The bearings of the
roller A are capable of moving, and are pressed up by levers and a weight, so
that the roller is capable of yielding a little in the event of the compression
being too great. This machine is very powerful, and works continuously.
Having now described the nature of the Invention, and in what manner the
same is to be performed, I wish it to be understood that what I claim is,―
First, the combination of a jogging sieve, having two or more perforated
plates or gratings, with one or two or more pairs of rollers for crushing the
coal, as herein-before described in reference to Figures 3, 4, 5, and 6.
Second, constructing water-sifting apparatus for purifying or separating
coal from foreign matters, as herein-before described, with an endless chain
of paddles or buckets, or similar mechanical means, for raising the purified
coal out of the water, as herein-before described.
Third, constructing water-sifting apparatus for purifying coal in combination
with an endless chain of paddles working over an inclined surface, or with a
revolving helical blade or screw, working in an inclined trough, for raising the
coal out of the water, as herein-before described.
Fourth, the mode of transferring the purified coal from the water-sifting
apparatus over a submerged partition, into an adjoining chamber filled with
water, by the action of the piston, or by the motion of the water-sifting
apparatus, in manner herein-before described.
Fifth, the combination of water-sifting apparatus for purifying coal with a
chamber or vessel for receiving the purified coal from the water-sifting chest,
which chamber is divided into two compartments, one of which is provided
B

page_text: with an overflow passage for the water, while the other compartuient is pro-
vided with an endless chain of paddles, or other similar mechanical means, for
raising the purified coal out of the water, as herein-before described in reference
to Figures 1 and 2.
Sixth, the combination of water-sifting apparatus for purifying coal, con-
structed as herein before described, with a chamber or vessel for receiving or
containing water, and for receiving the purified coal as it passes over from the
water-sifting chest, which chamber is provided with an endless chain of paddles,
or other similar mechanical means, for raising the purified coal out of the water,
and is or is not provided with an overflow passage for the water, as herein-
before described.
Seventh, constructing water-sifting apparatus for purifying coal with a steam
engine mounted on the apparatus itself, and driving it directly, as hercin-before
described.
Eighth, the combination of parts forming the water-sifting apparatus for
purifying coal, herein-before described in reference to Figures 7, 8, and 8 bis.
Ninth, the mode of clarifying the water which has been used in coal-purifying
apparatus, and extracting the fine coal from it, by causing it to overflow with a
very moderate velocity, and in a wide thin sheet, from one to another of a
series of vessels, as herein-before described.
Tenth, constructing apparatus for draining the water out of wet coal, by
the combination of draining bins, with mechanical means for distributing the
coal in them and collecting it from them, as herein-before described.
Eleventh, the mode of and apparatus for drying the coal, by moving it by
means of a screw or other mechanical means along a trough, in which it is
exposed to and permeated by currents of heated air or gases, as herein-before
described.
Twelfth, the combination of the draining bins, and the mechanical means of
distributing and collecting the coal, with the apparatus for drying the coal by
heated air or gases, as herein-before described.
Thirteenth, the construction and application of the heating apparatus with
revolving helical blades or screws for agglomerating coal, as herein-before
described.
Fourteenth, the machinery for compressing and moulding agglomerated
coal or artificial fuel, herein-before described in reference to Figures 12
and 19.
Fifteenth, the machinery for compressing and moulding agglomerated coal
or artificial fuel, herein-before described in reference to Figures 15 and 16.

page_text: Sixteenth, the improvements in the treatment of coal, by submitting it to
the successive processes of purification and desiccation, or of purification,
desiccation, and agglomeration, in the manner and by means of the improved
machinery and apparatus herein-before described.
In witness whereof, I, the said Charles Cowper, have hereunto set my
hand and seal, this Twenty-fifth day of November, in the year of our
Lord One thousand eight hundred and fifty-six.
CHARLES COWPER. (L.s.)