Improvements in Washing Coal for the purpose of Recovering the Fine or Small Coal from, the Effluent Washing Water and for the Drying of the Washed Coal.
Year: 1898

page_text: Date of Application, 26th May, 1898
Complete Specification Left, 27th Feb., 1899-Accepted, 20th May, 1899
PROVISIONAL SPECIFICATION.
Improvements in Washing Coal for the purpose of Recovering the
Fine or Small Coal from, the Effluent Washing Water and for the
Drying of the Washed Coal.
I, CUTHBERT BURNETT, of The Grange, near Durham, in the County of
Durham, Engineer, do hereby declare the nature of this invention to be as
follows:-
These improvements refer to apparatus to be applied in connection with coal
washing apparatus and have for object to retain the fine coal held in suspension
by the effluent water and so return the water to the pumps in a clean or compara-
tively clean condition. Another object is to dry the washed coal before it is
conveyed into any desired receptacle for loading into trucks or conveyed into
trucks direct. These improvements have more especial reference to the washing
of so called smudge, slack or duff or of coal containing a fair proportion of same.
The washed coal with the water is delivered by the coal washing apparatus
into a hopper and falls thence into a gutter or chamber provided with perforated
false bottom and provided with an endless conveyor said gutter rising in a
slanting direction with a discharge spout at that end for delivery into another
hopper adapted to receive the coal and which may be provided with perforations
at or near the bottom for a final draining of the coal before it is delivered into a
truck or other receptacle.
The conveyor may be in the form of an endless chain band passing round a
hexagon roller at each end and provided with dams which clear the perforated
false bottom of the gutter by say two or three inches, the layer of coal thus
left beneath forming a filter for the effluent water and serving to retain much
of the fine coal, the thus cleaned water being conveyed back to the pump to be
re-circulated in the washing apparatus. But in order to prevent the small
coal from choking up the gutter and impairing the filtration I make one of them
so deep as to reach closely to the false bottom, and one or more adjoining dams
may be of intermediate depths. The perforations in the false bottom may be
in a part or in the whole length of the false bottom. The water runs off at the
lower end of the gutter. The conveyor might be in the form of a perforated
belt or of other suitable form.
In order to dry the washed coal I provide an exhausting fan or equivalent
device at the discharge end of the gutter; such a fan may be driven by a belt
or by gearing or from an engine direct. The opening to the fan may be just
under the false bottom. The other or lower end of the gutter is connected with
a water seal the pressure in which is higher than the blast pressure.
The gutter may be slanting all the way or partly horizontal. The coal so treated
ought to be dry enough for conversion into coke without further drying.
-

page_text: Improvements in Washing Coal for the purpose of Recovering the
Fine or Small Coal from the Effluent Washing Water and for the
Drying of the Washed Coal.
I, CUTHBERT BURNETT, of The Grange, near Durham, in the County of
Durham, 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:—
These improvements refer to apparatus to be applied in connection with coal
washing plant and have for object to retain the fine coal held in suspension by
the effluent water sc that the water freed from the small coal can be returned
to the pumps in a clean or comparatively clean condition and be utilized again
for washing the coal. Another object is to dry the washed and drained coal
before it is conveyed into any desired receptacle or loaded into trucks direct.
These improvements have more especial reference to the washing of so-called
smudge slack or duff coal or of coal containing a fair proportion of same.
Fig. 1 Sheets 1 and 2 of the accompanying drawings is a part sectional side
elevation of such an apparatus, and Fig. 2 a vertical cross section on line ab,
Fig. 1.
The washed coal with the water is delivered by the spout A from the coal
washing apparatus into a hopper A' which is perforated at the bottom for draining
off the water and falls thence past a regulating slide B against a baffle plate Ü
and on to the perforated false bottom D of a gutter or chamber provided with
an endless conveyor. The perforated boitom D) serves to drain the water from
the coal. The perforations may be in a part or in the whole length of the false
bottom. The gutter rises in a slanting direction and has a discharge spout Fat
the upper end for delivery into a truck or other receptacle not shewn; or in
some cases first into another hopper provided with perforations at or near the
bottom for a final draining of the fine coal.
The conveyor may, as here shewn, be in the form of an endless chain band
or chains T passing round a hexagonal roller G at each end and provided with
dams E which clear the perforated false bottom D of the gutter by say 2 or 3
inches, the layer of coal thus left beneath forming a filter for the effluent water
and serving to retain much of the fine coal. The water thus cleaned uns off
at the bottom end of the gutter by a pipe I into a well, whence it is conveyed
back by a pulsometer or other pump K (see Figure 3) to be recirculated in the
washing apparatus. In order to prevent the small coal from choking up the
gutter and impairing the filtration I make one dam E so deep as to touch or
nearly touch the perforated bottom D and one or more of the dams such
as EE and E3 may be of intermediate depths. It will be understood that on
each complete circuit of the chain and dams the filtering bed of fine coal will
have been removed.
In order to dry the wet washed coal I provide an exhausting fan H or equiva-
·lent device. Such a fan may be driven by a belt or by gearing or from an engine
direct. It is connected to the discharge end of the chamber by a pipe L. The
gutter is here formed as an annular chamber closed at the top.
descends so far into the well as to be sealed and with a head of water higher
The pipe I
than that of the air current produced by the fan.
. The coal. treated as described is dry enough for conversion into coke without
further or but little drying.

page_text: As the water cannot be rendered perfectly clear it follows that some fine coại
and impurities will be deposited in the well. But in order to prevent accumu-
lation thereof I provide a small elevator the lower end of which I fix in the well..
and the upper end I arrange conveniently for delivery of the said fine coal sand
and other impurities to the washing apparatus to be treated again. This
arrangement possesses another important advantage; in cases where the fine coal
is known to be mixed with a larger than desirable proportion of fine' pyrites or
sand I employ a larger than usual draining area in the bottom of the hopper A¹
and allow the water to pass thence direct to the well.
Fig. 3 is a side elevation of such an arrangement and forming also a complete
view of the combination of this invention with a Wood-Burnett washer M made
according to their Patents 8478 of 1892 and 4380 of 1894. The elevator N raises
the fine coal, sand and other impurities and discharges it into the washer M
wherein it passes along preferably together with larger coal and is discharged
at the lower end by the spout A. Or the fine material might be passed into a
separate small washer.
Fig. 4 Sheets 4 and 5 is a sectional side view of a modified arrangement and
Fig. 5 a vertical cross section on lines e-d and e-f Fig. 4. The washer M in
this case delivers directly into the hopper or shoot A against the baffle plate C
and directly upon the endless conveyor belt consisting of a number of perforated
trays T¹ mounted on links or chain composed of iron or steel cheeks T filled in
with pieces of wood U. The said composite links work in sliding contact with
an angle iron V so as to render it comparatively air tight. The belt with its
chains is mounted on a hexagonal drum G at each end having their bearings
in a frame supported on pillar P. C is a flexible baffler, say of india rubber,
attached to the inside of the hopper A¹ to prevent the water from passing off
clear of the coal underneath the belt. D) is an air chamber or drainage box
arranged within the belt or below its upper web and provided with a perforated
box to this latter is connected the pipe L leading to the exhauster H for
extracting the water. The pulleys RR serve to guide the belt on and off the
air chamber D¹. The water is returned to the well or other receiver by the
pipe I. The dried washed coal is delivered direct into a truck or other receptacle.
Qis a drip trough for receiving the water dripping from the sides of the apparatus.
SS are flexible strips say of india rubber for preventing the admission of air
from the outside of the air chamber D¹.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
claim is:-
1. The mode of removing fine coal and other small particles from water which
has been used for washing coal, comprising the employment of a chamber.
provided with a conveyor and a perforated false bottom, at or near one end of
which chamber the coal and water are admitted and wherein the water is drained
off while the fine coal and other small particles are deposited on the said perforated
false bottom and exposed to a moisture extracting air current, said deposit being
periodically removed, while the water in a cleansed condition is withdrawn and
can be utilized again for washing coal, substantially as described.
2. In coal washing plant, the combination of a hopper or spout which receives
the fine coal and other particles of matter coming with the water from the
washer, a drainage box or chamber a perforated endless conveyor for receiving the
coal and the water from the hopper or spout and for conveying the solid particles
along the top of the chamber while the water filters through the perforated
conveyor into the said chamber and drains off at or near one end, an exhausting
fan for drawing off the moisture through the said perforated conveyor and the
said chamber in order to dry the solid particles, and a pump for raising the
cleansed water so that it may if desired be used again for washing coal
substantially as set forth.

page_text: 3. The construction of chamber with conveyor as described with reference to
Figs. 1 and 2.
4. The construction of combined coal washing apparatus as shewn in
Figs. 1, 2 and 3.
5. The construction of chamber with conveyor as described with reference to
Figs. 4 and 5, .
Dated this Twenty-seventh day of February 1899.
JENSEN & SON,
77, Chancery Lane, London, W.C..
Patent Agents.