Improvements in Machinery for Washing Coal and Coke and other Minerals and Materials.
Year: 1892

page_text: Date of Application, 4th May, 1892
Complete Specification Left, 6th Feb., 1893-Accepted, 25th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in Machinery for Washing Coal and Coke and other
Minerals and Materials.
We WILLIAM OUTTERSON WOOD of South Hetton in the County of Durham
Mining Engineer and CUTHBERT BURNETT of Fallowfield South Hetton aforesaid
Engineer do hereby declare the nature of this invention to be as follows:-
The object of our invention is to provide machinery for washing coal and coke
and other minerals and materials in a continuous and, so to say, automatic manner,
whereby the impurities are separated therefrom more perfectly than heretofore and
at a minimum cost of labour.
The coal or other material to be washed is delivered from a hopper or other
source of supply on to an endless moving band having a suitable downward inclination
towards a receptacle for the cleaned coals. We prefer to use a hopper for the
purpose of ensuring a uniform distribution of the coal to and over the endless band
and instead of an ordinary slide for controlling the supply of coal we may use a
screw or other positive feed arrangement. Together with the coal we provide a
supply of water whereby the coal is washed down towards the said receptacle,
a strainer being provided at that end for draining the water into a tank whence it
may be pumped up for repeated use. The endless band or belt is generally at
convenient intervals provided with dams cross boards or the like and receives a
motion in a direction, opposite to that of the downward flow of the water, towards
the washed coal receptacle, the object of the dams being to intercept the impurities
and to deposit them in a tank at the higher end. The speed of the ascending belt
and the speed of the descending water are so apportioned as to produce the desired
washing along or floating down of the coal or other material at the proper rate for
each kind or quality of material. The coal to be washed may be properly sized
and each grade washed separately over the same belt or a separate belt may be
employed for each grade; the coal may be crushed through rollers or otherwise
rendered as much as possible of uniform grade. By means of suitable gearing the
speed of the machine may be so regulated as to meet the special requirements of
each kind and grade of coal, an increase in the speed of the belt tending to prolong
the time that the coal is subjected to the washing process and vice versa. The belt
may also receive an oscillating movement. Besides the aforesaid supply of water
we also by preference provide a water sprinkling supply for wetting the coal as it
is delivered to the endless belt. In such cases where screw feed arrangement is
used we may admit the water into the screw casing for the purpose of wetting
the coal.
The endless belt may either be working in a trough or partly form a trough. In
the former case the endless belt may be of canvas or other suitable flexible material
and with sides made of layers of leather or other flexible material and having
dams fixed thereto, the belt passing over a cylindrical drum at each end, or the
belt may be made of trays with upstanding sides of rigid material and with dams
fixed to chain, the belt passing over polygonal drums or sprocket wheels at each
end, narrow dams or stops being by preference provided at suitable intervals below
to prevent undue waste of water which would pass through the joints of ends and sides
of trays. Or we may use an endless web of canvas or other suitable flexible
material having the dams affixed thereto and having lateral flexible or hinged side
parts which by means of stationary inclined rollers arranged along the upper part
of the belt are made to gradually raise the side parts into trough shape, the said
parts falling down flat while passing over the drums at each end and during

page_text: the return passage and the drums being of a width to take the belt in its flat
condition.
The middle portion of the belt is also supported by rollers and one or more
rollers may be employed to support the returning portion of the belt. The flexible
trough side may instead of running on the rollers directly, rest on and travel with a
separate band running at suitable tension on the said inclined rollers. This
arrangement would permit the side strips of band being made of a thinner material
whilst at the same time increased strength and greater uniformity in width is
secured and the latter particularly is important in the case of troughs of this class
where dams are employed. We by preference clean the belt by water jet or jets
and scrapers if necessary while it passes round the upper drum and hence the trough
is always clean at the end where the final washing takes place.
The water for washing may be delivered at one or more points at or near the
upper end of the belt or trough and the coal thereto just below the water delivery.
In some cases we pass the washed coal over a perforated spout into a receptacle
and let the water drain into a tank below and pump it back thence to the supply
system. Sometimes we pass the dirty water by a spout into a settling back
or tank along with the fine coal held in suspension in which the said fine coal is
precipitated and is by a suitable feeding arrangement delivered on to a separate
lower band or trough of similar construction to one of those described the water
supply for which may be either by an overflow from the settling tank or a stream
of clean water may be used. The fine washed coal is delivered over a strainer
and thence into a receptacle whence it may be raised by an elevator to the aforesaid
washed coal receptacle.
For agitating the coal during the process of washing we propose to use rakes
which are worked mechanically from side to side or longitudinally. These rakes
when worked longitudinally may be jointed so as to be lifted over the dams and
we prefer to apply to them slow forward and quick return motion by means of cam
gear. In one such arrangement we hinge the rakes to a bar which is supported by
rollers on stationary rails the rake bar receiving the required reciprocating motion
from a bell-crank-lever-like quadrant having rollers working against the outer and
inner face of a rim on a cam wheel the fulcrum of the quadrant being on a lever
which receives oscillating motion from a crank pin in the cam wheel such pin
with block or rollers thereon working in a slot in the lever.
In such bands or troughs as are used for washing the fine coal we may dispense
with the use of both dams and rakes.
At the lower end of the band or trough or bands or troughs for the more
effectual drainage of the water from the coal we may apply a creeper or creepers
or endless band or bands which slowly pass the washed coal over a perforated tray
and thence into the receptacle for the washed coal the latter may also be fitted
with drain plates.
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Machinery for Washing Coal and Coke and other
Minerals and Materials.
We, WILLIAM OUTTERSON WOOD of South Hetton in the County of Durham
Mining Engineer and CUTHBERT BURNETT of Fallowfield South Hetton afore-
said Engineer do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in and by
the following statement :-
The object of our invention is to provide machinery for washing coal and coke
and other minerals and materials in a continuous and so to say automatic manner

page_text: whereby the impurities are separated therefrom more perfectly than heretofore and
at a minimum cost of labour.
In the accompanying drawings we have illustrated the invention and a suitable
manner of carrying it into effect
Fig. 1 being a plan showing the general arrangement of a coal washing plant
according to our invention, Fig 2 a side elevation and Figs. 3 and 4 end
elevations.
Besides
The coal or other material to be washed is delivered from a hopper or other
source of supply on to an endless moving band or belt having a suitable downward
inclination towards a receptacle for the cleaned coals. This angle is by preference
made adjustable. In the present example we have shown four such bands or
belts F and F and F and F side by side in pairs to economise space.
these belts there is a belt F for recovery of the fine coal from the sludge as
precipitated in a settling tank. We prefer to use a hopper such as A for the
purpose of ensuring a uniform distribution of the coal to and over the endless
band or bands and instead of an ordinary slide for controlling the supply of coal
we may use a screw or paddle or other positive feed arrangement at the end of the
coal hopper spout A¹ together with coal we provide a supply of water whereby
the coal is washed down towards the receptacle C for the cleaned coals. B and
Bare two pipes from a cistern Q for water supply one just behind the spout A' and
the other some distance back so as to wash out any coal which might otherwise
pass off with the dirt and be washed, a strainer D being provided at that end for
each pair of belts for draining the water into a tank E whence it may be pumped
up for repeated use. Each endless band, or belt is generally at convenient intervals
provided with dams, crossboards or the like presently to be described and receives
a motion in a direction indicated by the arrows or opposite to that of the downward
flow of the water towards the washed coal receptacle C the object of the dams
being to intercept the impurities and to deposit them in a tank or dirt
hopper G at the higher end. The speed of the ascending belt and the
speed of the descending water are so apportioned as to produce the
desired washing along or floating down of the coal or other material at
the proper rate for each kind or quality of material. The coal to be
washed may be properly sized and each grade washed separately over the
same belt or a separate belt may be employed for each grade. The coal may be
first crushed through rollers or otherwise rendered as much as possible of uniform
grade. By means of suitable gearing the speed of the machine may be so
regulated as to meet the special requirements of each kind and grade of coal, an
increase in the speed of the belt tending to prolong the time that the coal is
subjected to the washing process and vice versa. The belt may also receive an
oscillating movement. Besides the aforesaid supply of water by the pipes B and B¹
we also by preference provide a water sprinkling supply at B for wetting the coal
as it is delivered to the endless belt. The belt F for recovery of fine coal from
the sludge has only one water supply pipe B* at a suitable angle and by preference
delivering the water in a fine spray. The fine coal and the water are both
discharged at the hopper C the water being drained off through the body of coal
as discharged from the belt the result being that most of the fine coal is retained
mixed with the large coal and the water drained off. In such cases where screw
feed arrangements are used we may admit the water into the screw casing for the
purpose of wetting the coal.
The endless belt may either be working in a trough or partly form a trough.
In the former case the endless belt may as shewn in Figs. 5 to 9 be made of trays
with upstanding sides of rigid material and with dams fixed to the chain. Figure 5
is a plan and Figure 6 a longitudinal section through such a belt, Figure 7 is a
vertical transverse section. Figures 84 and 88 are side views of the end parts of
belt and Figure 9 a transverse section through a drum. The belt F1 passes over
polygonal drums or sprocket wheels H at each end and consist of steel plates
riveted or bolted to chains I; the plates have upstanding sides and their ends are

page_text: curved up see Figure 6. The axles H' of the drums H are at one end mounted in
blocks H sliding in guide slots in brackets M and capable of adjustment therein
by means of screws M' and nuts M' so that the endless belts may be kept as taut
as convenient. Narrow dams or stops may be provided at suitable intervals below
to prevent undue waste of water which would pass through the joints of ends and
sides of trays.
We may as shown in the transverse section Figure 10 use an endless web Fi
of canvas or other suitable flexible material, the web passing over a cylindrical
drum at each end and having dams N affixed thereto and having lateral flexible or
hinged side parts N¹ which by means of stationary inclined rollers arranged
along the upper part of the belt are made to gradually raise the side parts N¹ and
side part of the canvas web F¹ into trough shape the said parts falling down flat
while passing over the drums H at each end and during the return passage and the
drums being of a width or so spaced apart as to take the belt in its flat condition.
The middle upper portion of the belt F' is also supported by rollers K and one
or more rollers L may be employed to support the lower or returning portion of
the belt. The flexible trough side may instead of running on the rollers O directly
rest on and travel with a separate band running at suitable tension on the said
inclined rollers. This arrangement would permit the side strips of band being
made of a thinner material whilst at the same time increased strength and greater
uniformity in width is secured and the latter particularly is important in the case
of troughs of this class where dams are employed. We by preference clean the
belt by water jet or jets and scrapers if necessary while it passes round the upper
drum and hence the trough is always clean at the end where the final washing
takes place.
The water for washing may be delivered at one or more points at or near the
upper end of the belt or trough and the coal thereto just below the water delivery
but we prefer the arrangement shown and described. In some cases and as already
described with reference to Figures 1 to 4 we pass the washed coal over a perforated
spout or strainer D into a receptacle C and let the water drain into a tank E below
and pump it back thence say by a pistonless pump P to the supply cistern the
used water from the sludge tank or well E is along with the small amount of
remaining fine coal held in suspension by preference pumped up into the settling
tank R in which the said fine coal is precipitated and is by a suitable feeding
arrangement such as the spout R¹ delivered on to a separate band or trough F' of
similar construction to one of those described, the water supply for which may be
either by an overflow pipe B* from the settling tank R or a stream of clean water
may be used. The fine washed coal with the small quantity of water used is
delivered over a plain spout into say the centre of the receptacle C whence it may
be raised along with other washed coal by the elevator U to the aforesaid washed
coal receptacle V and the water drained therefromn by filtering through the coal
from the main belts. When more than one class of coal is to be treated separation
of the different grades could be effected by suitable screens or riddles or an
elevator could be used for each kind and the plant would require to be at such an
elevation that the different sorts of washed coals could be delivered direct into the
hoppers trucks or wagons, or as an alternative arrangement a separate elevator
could be used for each kind. G and G¹ are the dirt hoppers, SS are coke ovens
and T dirt wagons. We do not restrict ourselves to the washing of coals for
coking merely, but also for increasing the commercial value of coal generally.
For agitating the coal during the process of washing we propose to use rakes
which are worked mechanically from side to side or longitudinally. These rakes
when worked longitudinally may be jointed so as to be lifted over the dams and we
prefer to apply to them slow forward and quick return motion by means of cam
gear. In one such arrangement shown in the side view Fig. 11 as applied to a belt
of the construction in Fig. 10 we hinge the rakes a to a bar b which is supported by
rollers c on stationary rails d the rake bar receiving the required reciprocating
motion from a connecting rod b¹ and bell-crank-lever e or quadrant having rollers

page_text: working against the outer and inner face of a rim on a cam wheel g the fulcrum
of the bell crank lever e being on a lever having its fulcrum at h³ and which
receives oscillating motion from a crank pin i in the cam wheel g, such, pin with
block or roller thereon working in a slot in the lever h. The effect of this
arrangement is that the rakes receive slow forward and quick return motion and
that in the forward motion three or four rakings are effected. This is owing to the
form of cam wheel g for during the return stroke of the rakes the rollers frun on
the true circular part of the cam wheel while on the other the rollers work on the
irregular or cam part and cause the rakes to be worked and lifted while passing
over the dams N. With some kinds of coal it may only be necessary to employ
rakes between the point at which the coal is delivered on to the belt and the
water jet.
In such bands or troughs as are used for washing the fine coal we may dispense
with the use of both dams and rakes.
At the lower end of the band or trough or bands or troughs for the more effectual
drainage of the water from the coal we may apply a creeper or creepers or endless
band or bands which slowly pass the washed coal over a perforated tray and thence
into the receptacle for the washed coal; the latter may also be fitted with drain
plates.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
First. A coal washing apparatus consisting of one or more endless belts formed
with upstanding sides or working in a trough and having an inclination towards
the washed coal delivery end and moving in a direction away from it, in combination
with a hopper, spout and regulating slide or equivalent means for supplying the
belt evenly with coals, means for delivering water on to the coals on the belt in the
rear of the spout, with or without water spray supply in front of it with or without
rake appliances for agitating or moving the coal on the belt, a receptacle for the
cleaned coal with elevator when required for raising its contents, a sludge tank with
strainer at the lower or delivery end of belt, and a dirt receptacle at the other end,
substantially as set forth.
Second. A coal washing apparatus as firstly claimed in combination with means for
raising water, containing fine coal, from the sludge tank to a settling tank, and
additional endless cleaning belt, fine coal supply to the said belt from the settling
tank, and water supply to the said belt, substantially as set forth.
Third. The construction of endless coal washing belt with metallic tray plates
and chains in combination with polygonal drum substantially as set forth.
Fourth. The construction of endless coal washing belt with flexible web in com-
bination with stationary inclined rollers for turning up the edges of the web and
round drums substantially as set forth.
Fifth. The described construction of mechanical rakes and the gear for working
same.
Sixth. The construction of coal washing plant shown on the drawings.
Doted this 6th dor of Bohm 1902
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.