Im- PROVEMENTS IN THE PRODUCTION OF FINELY POWDERED COAL APPLICABLE FOR PROVISIONAL SPECIFICATIONLICABLE FOR BEING BURNT TOGETHER WITH AIR IN PUDDLING AND OTHER FURNACES
Year: 1875

page_text: LETTERS PATENT to Robert Ferry, of Francis Street, Hartlepool, in
the County of Durham, Millwright, for the Invention of "Im-
PROVEMENTS IN THE PRODUCTION OF FINELY POWDERED COAL APPLICABLE FOR
PROVISIONAL SPECIFICATION left by the said Robert Ferry at the
Office of the Commissioners of Patents, with his Petition, on the
26th October 1875.
I, ROBERT FERRY, of Francis Street, Hartlepool, in the County of
Durham, Millwright, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE PRODUCTION OF FINELY POWDERED COAL APPLICABLE
FOR BEING BURNT TOGETHER WITH AIR IN PUDDLING AND OTHER FURNACES," to be
as follows:-
This Invention has for its object improvements in the production of
finely powdered coal applicable for being burnt together with air in
puddling and other furnaces.

page_text: In order that coal may usefully and with profit be burnt in the state
of dust in revolving, puddling, and other furnaces it is essential that the
coal should be reduced at very small cost to an extremely fine and
uniform powder. This I effect by means of a system of crushing, drying,
grinding, and sifting apparatus, as herein-after described.
The coal to be reduced is dropped into a hopper, from the bottom of
which it is discharged and received between a pair of fluted rollers
gearing with one another. One of the rollers is free to move to or from
the other roller, and is kept up towards it by a weighted lever or other-
wise. At the lower part of the hopper is a cross shaft with projecting
prongs, and as the shaft is revolved the prongs keep the coal in move-
ment and discharge it from the opening at the bottom of the hopper.
This opening may be enlarged or decreased by a moveable slide to
regulate the quantity discharged. The coal after being crushed by the
pair of corrugated rollers drops to a pair of plain smooth rollers, which
are similarly kept together by weighted levers or otherwise, and after
being crushed by these rollers passes to a drying apparatus.
The pairs of corrugated and plain rollers above mentioned are both
driven from toothed wheels on a shaft placed centrally between
them.
The drying apparatus I construct of a revolving cylinder made of
wrought-iron plate and strengthening bars. The cylinder runs upon
cast-iron rollers and bridges or bearers, and the heated gases from a
furnace are caused to pass through it. On the exterior of the cylinder
is carried (by wrought-iron arms, and at some distance from it) a
surrounding cylinder with six, eight, or other number of sides. The
covering plates of this outer polygonal cylinder are of sheet iron, about
3/16 inch thick, and these sides are secured to longitudinal bars with bolts
and nuts, so that any of the plates when worn out may be readily
detached and renewed. This polygonal cylinder is contained within a
flue from a furnace, and the flue is continued to lead into the lower end
of the cylindrical flue which passes through the polygonal cylinder.
The heated gases are drawn through this cylindrical flue by the draught
of a chimney or otherwise. A blast of cold air is admitted to one end
of the polygonal cylinder, and is drawn through and away from the
cylinder by a suction draught. The revolving cylinder is driven by spur
gear from the crushing rollers or other shaft in the coal dust mill, so as

page_text: to drive it at about 15 to 25 revolutions a minute. It also lies at an
incline, and the coal to be dried is introduced into it at its upper end,
and is discharged from it at its lower end.
The inclination of the cylinder can be varied from time to time if
desired by an adjusting lever. Or in place of employing a revolving
cylinder as above described for drying the crushed coal, the crushed coal
may be received on to an endless travelling band and carried by it
through a licated flue.
The endless band I form of iron plates hinge jointed to one another,
and with rollers carried by the pins of the hinge joints to run on sup-
porting rails. The band also passes over two square or hexagonal
revolving shafts or drums.
The crushed coal, after being carried by either of the above means
through a drying chamber, is delivered into a hopper, from which it is
carried by elevators to be delivered to millstones to be ground, and from
the millstones it passes through a spout to the dressing machine to be
sifted or dressed, and the finely sifted dust thereby obtained is again
lifted by an elevator into tanks or receptaclos.
For grinding the crushed coal to a fine powder I employ millstones
similar to the stones employed for grinding corn.
The means I adopt for feeding the crushed coals into the centre or
eye of the millstones are as follows:-The cords are put into a hopper,
and at the bottom of the hopper is a moving shoe to which a vibratory
motion is given from an upright shaft driven with the top stone; the
shoc delivers the coals into a spout leading into the centre tube of the
casing which enters into top millstone. This tube has a covering plate
on top, and through it is passed a cold blast spout for the purpose of
keeping the millstones cold; or the upright shaft can have a screw on
instead of employing the moving shoe and feed the coal from the hopper
by the screw. The crushed coal passes with the cold blast between the
stones, and from the casing surrounding the exterior of the stones a
suction pipe is led to a condensing room and stive chamber covered
with canvass. This suction pipe passes away radially from the opposite
side of the casing to that at which the outlet spout for the ground coal
is situated. The dust passing by the outlet spout from the millstones
passes at once to a silk dressing or sifting machine.

page_text: Within the
This machine is composed of a casing of wood or iron, the upper part
of the casing is fitted with doors covered with canvass.
casing is mounted an inclined revolving reel or drum, the sides of which
are covered with silk, the reel is formed of wooden rails carried by iron
arms, and may be hexagonal or of other number of sides, and is provided
with rappers carried by arms leading on to the centre shaft, and these
rappers give a vibratory movement to the silk and detach the coal dust
from it. Means are also provided for throwing these rappers out of
action. Within the upper end of the reel is carried a catch box. This
box arrests the stream of coal dust as it passes from a shoot into the
reel and causes it to enter the reel quietly; it is also arranged to keep
back any lumps or particles which might be sufficiently heavy to injure
the silks. The dust, which is fine enough to pass through the silk, drops
to the bottom of the outer casing. At the bottom of the casing is a
revolving screw by which the fine dust is delivered to an elevator to be
conveyed to a suitable tank or receptacle, as before mentioned. A cold
blast is blown into the silk reel somewhere near its centre, and an escape
trap is provided on the top of the reel casing.
The particles which will not pass through the silk sieves drop away
from the sieve at its lower end into a shoot, by which they are conveyed
to an elevator which passes them back to the millstones to be reground.
The hopper from which the rough coal is supplied to the crushing
rollers is at the upper part of the building containing the machinery
above described. The crushed coal falls from the crushing rollers into
the drying machine. The exit spout from the drying machine leads the
dried dust to an elevator which lifts the dust to the upper part of the
building and delivers it into the hopper from which the millstones are
supplied; as it passes from the millstones it falls into the silk dresser and
the dressed dust collected in the dresser is lifted by an elevator into a
tank or receptacle at the upper part of the building, from which it is
afterwards conveyed away to the furnaces as required.
The several pairs of grinding stones are ranged in a straight row,
parallel with which is a row of silk dressing machines. The dressing
machines each lie at a right angle to the main driving shaft from which
they and the grinding stones are driven. The grinding stones and
dressing machines are contained in one compartment of the building,
and at the end of this compartment is an engine room for containing

page_text: the driving engine. The crushing and drying machinery is contained in
another compartment at the back of the two compartments first
mentioned. The coal dust mill is arranged also to have one pair of
rough coal elevators to two pairs of millstones.
To each millstone is a separate silk dressing machine and one pair of
return dust elevators for every two silk dressing machines for the
purpose of carrying the return coal dust back to the millstones to be
reground.
Each silk dressing machine has a screw to carry the fine dust to a
main screw which conveys the dust to the end of the mill house, and
from there it is lifted by elevators to tanks or reservoirs, as before
stated.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Ferry in the Great Seal Patent Office on
the 26th April 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
FERRY, of Francis Street, Hartlepool, in the County of Durham, Mill.
wright, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of October, in the
year of our Lord One thousand eight hundred and seventy-five, in the
thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Robert Ferry, Her special
license that I, the said Robert Ferry, my executors, administrators, and
assigns, or such others as I, the said Robert Ferry, 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 PRODUCTION OF FINELY POWDERED COAL APPLICABLE FOR BEING BURNT
TOGETHER WITH AIR IN PUDDLING AND OTHER FURNACES," upon the condition
(amongst others) that I, the said Robert Ferry, my executors or

page_text: driven from toothed wheels on a shaft placed centrally between them, as
shown in the Drawings.
In place of employing crushing rollers, as above described, edge
running stones working in a perforated or grated pan may be used for
the purposo.
The drying apparatus shown at Figures 2, 3, 4, 5, and 6 I construct of
a revolving cylinder f made of wrought-iron plate and strengthening
bars. The cylinder runs upon cast-iron rollers f' and bridges or bearers,
and the heated gases from a furnace 9 are caused to pass through it.
On the exterior of the cylinder is carried (by wrought-iron arms and at
some distance from it) a surrounding cylinder f, with six, eight, or other
number of sides. The covering plates of this outer polygonal cylinder
are of sheet iron about 1 inch thick, and these sides are secured to
longitudinal bars with bolts and nuts, so that any of the plates when
worn out may be readily detached and renewed. This polygonal cylinder
is contained within a flue / from a furnace, and the flue is continued to
lead into the lower end of the cylindrical fluef, which passes through
the polygonal cylinder. The heated gases are drawn through this
cylindrical flue by the draught of a chimney or otherwise. A blast of
cold air is admitted by the pipe f³ to one end of the polygonal cylinder,
and is drawn through and away from the cylinder by a suction draught
produced by a revolving fan f*, as shown at Figure 2. The revolving
cylinder is driven by spur gear from the crushing rollers or other shaft
in the coal dust mill, so as to drive it at about 15 to 25 revolutions a
minute. It also lies at an incline, and the coal to be dried is introduced
into it at its upper end by a spout i leading from below the crushing
rollers, and is discharged from it at its lower end by a spout i'.
The inclination of the cylinder can be varied from to time, if
desired, by an adjusting lever; or in place of employing a revolving
cylinder, as above described, for drying the crushed coal, the crushed
coal
may be received on to an endless travelling band, and carried by it
through a heated fluc.
The endless band I form of iron plates ; hinge-jointed to one another,
as shown at Figures 7 and 8, and with rollers k carried by the pins of
the hinge joints to run on supporting rails; the band also passes over
two square or hexagonal revolving shafts or drums 1.

page_text: The crushed coal after being carried by either of the above means
through a drying chamber is delivered by the spout into a hopper,
from which it is carried by clevators to be delivered to the millstones
to be ground, as, shown in the end section of the whole combined
arrangement of crushing, grinding, and dressing machine shown at
Figure 9 of the Drawings. From the millstones it passes through a
spout to the dressing machine to be sifted or dressed, and the finely
sifted dust thereby obtained is again lifted by an clevator into tanks or
receptacles, as herein-after more fully described.
For grinding the crushed coal to a fine powder I employ millstones
similar to the stones employed for grinding corn. The millstones and
apparatus in connection therewith are shown separately at Figure 10.
The means I adopt for feeding the crushed coals into the centre or
eye of the millstones are as follows:-The coals are, as above described,
supplied by an elevator into a hopper m, and at the bottom of the
hopper is a moving shoe m' to which a vibratory motion is given from
The shoe delivers the
an upright shaft m² driven with the top stone n.
coals into a spout leading into the centre tube o' of the casing o. Tho
centre tube o' enters into top millstone, and has a covering plate of on
top, through it is also passed a cold blast spout for the purpose of
keeping the millstones cold. In place of this arrangement for feeding
dry crushed coal to the millstones the upright shaft m can have a
screw upon it instead of employing the moving shoe, and the coal may
be fed from the hopper by the screw. The crushed coal passes with the
cold blast between the stones, and from the casing o surrounding the
exterior of the stones a suction pipe o³ is led to a condensing room and
stive chamber covered with canvas. This sustion pipe passes away
radially from the opposite side of the casing to that at which the outlet
spout for the ground coal is situated. The dust passing by tho
outlet spout from the millstones passes at once to a silk dressing or
sifting machine.
This machine is shown separately at Figures 11, 12, 13, 14, 15, and 16.
It is composed of a casing of wood or iron; the upper part of the
casing is fitted with doors covered with canvas, as shown at Figure 11.
Within the casing is mounted an inclined revolving reel or drum 8, the
sides of which are covered with silk; the reel is formed of wooden rails
carried by iron arms, and may be hexagonal or of other number of sides,
and is provided with rappers & carried by arms leading on to the centre

page_text: shaft, and these rappers give a vibratory movement to the silk and
detach the coal dust from it. Means are also provided for throwing
thesc rappers out of action, as shown at Figure 14. Within the upper
end of the reel is carried a catch box w, as shewn at Figures 12 and 14;
this box is constructed of finely perforated sheet metal, and arrests the
stream of coal dust as it passes from a shoot into the reel, and causes it
to enter the reel quictly. It is also arranged to keep back any lumps
or particles which might be sufficiently heavy to injure the silks. The
dust, which is fine enough to pass through the silk, drops to the bottom
of the outer casing ”. At the bottom of the casing is a revolving
screw by which the fine dust is delivered to an elevator, as shown at
Figure 9, to be conveyed to a suitable tank or receptacle, as before
mentioned. A cold blast is blown into the silk reel somewhere near its
centre by a pipe to, see Figure 9, and au escape trap is provided on the
top of the reel casing.
The particles which will not pass through the silk sieves drop away
from the sieve at its lower end into a shoot x, from which they are
conveyed to an elevator which passes them back to the millstones to be
re-ground.
A ground plan of the combined arrangement of coal crushing,
grinding, and dressing machinery is shown at Figure 17, an end section
of the same is, as before stated, shown at Figure 9.
The hopper a from which the rough coal is supplied to the crushing
rollers is at the upper part of the building containing the machinery.
The crushed coal falls from the crushing rollers into the drying machine.
The exit spout from the drying machine leads the dried dust to an
elevator which lifts the dust to the upper part of the building, and
delivers it into the hopper m, from which the millstones are supplied;
as it passes from the millstones it falls into the silk dresser, and the
dressed dust collected in the dresser is liſted by an elevator into a tank
or receptacle at the upper part of the building, from which it is
afterwards conveyed away to the furnaces as required.
The several pairs of grinding stones are, as shown at Figure 17,
ranged in a straight row, parallel with which is a row of silk dressing
machines. The dressing machines each lie at a right angle to the main
driving shaft, from which they and the grinding stones are driven.
The grinding stones and dressing machines are contained in one com-

page_text: partment of the building, and at the end of this compartment is an
engine room for containing the driving engine. The crushing and
drying machinery is contained in another compartment at the back
of the two compartments first mentioned. The coal dust mill is
arranged also to have one pair of rough coal elevators to two pairs
of millstones.
To each millstone is a separate silk dressing machine, and one pair
of return dust elevators for every two silk dressing machines for the
purpose of carrying the return coal dust back to the millstones to be
re-ground.
Each silk dressing machine has a screw to carry the fine dust to a
main screw, which conveys the dust to the end of the mill house,
and from there it is lifted by elevators to tanks or reservoirs, as before
stated.
Having thus described the nature of my Invention, and the manner
of performing the same, I would have it understood that I claim,-
First. The combined arrangement of coal crushing, grinding, and
dressing machinery, substantially as herein-before described.
Second. The use of grinding machinery, constructed substantially as
herein before described, for grinding coal.
Third. The use of silk dressing machinery, constructed substantially
as herein-before described, for dressing powdered coal and preparing it
for being burnt together with air in puddling and other furnaces.
In witness whereof, I, the said Robert Ferry, have hereunto
set my hand and seal, this Twenty-fourth day of April, in
the year of our Lord One thousand eight hundred and seventy-
six.
Signed and sealed by the said
Robert Ferry in the presence of
J. F. KAY,
Solicitor,
West Hartlepool.
ROBERT FERRY. (L.S.)