Improvements in Means for Filtering Water from Washed Coal or like Mineral, and for Recovering Coal or like Mineral from such Water.
Year: 1895

page_text: Date of Application, 28th Mar., 1895
Complete Specification Left, 30th Dec., 1895-Accepted, 22nd Feb., 1896
PROVISIONAL SPECIFICATION.
Improvements in Means for Filtering Water from Washed Coal or
like Mineral, and for Recovering Coal or like Mineral from such
Water.
We, CHARLES CRAIG, WILLIAM CRAIG and GEORGE KERR CRAIG all of
Sacriston in the County of Durham, Contractors, do hereby declare the nature of
this invention to be as follows:-
:―
This invention relates to improvements in meaus for filtering water from washed
coal or like mineral and for recovering coal or like mineral from such water.
For example in the washing of coal it is a common practice after the stone and
dirt have been removed therefrom to allow the washed coal and water to pass away
together and to allow the water remaining in or with the coal to drain away to
filter or other beds where the water is eventually extracted from the fine coal and
allowed to drain to waste in a condition still retaining a quantity of fine coal in
suspension.
By this arrangement it is found in practice that a material waste of coal is
continually taking place and considerable cost is also involved in relifting the
filtered small coal from the beds for use in certain kinds of work where only an
inferior class of coal is required.
Now by our invention we interpose between the washing machine and the
wagons or the like into which the mineral is intended to be loaded a filtering or
draining apparatus which may consist of a receptacle of suitable capacity and
form and into which the washed coal or mineral and water (or as much of the
latter as has not gone away with the dirt already extracted during the washing
process) are discharged.
The receptacle may be fitted internally with a central vertical or other shaft
fitted with central vertical or other arms or blades and with one or more horizontal
or other arms or scraper devices the whole being adapted to revolve when required
by suitable toothed or other gearing mounted above or in connection with the
receptacle.
The horizontal arms or scraper device may in certain cases be fitted and
counterbalanced so as to be adapted to slide up and down the central shaft the
object of this contrivance being to relieve or open the centre of the mass of coal
or mineral so as to concentrate it towards the basal opening or outlet in the
receptacle.
The receptacle may be furnished at or near its base with a cloth or strainer
device or with two or more such devices between any two of which if found
desirable a certain thickness of filtering material such as small coal or equivalent.
material may be interposed and beneath the lower strainer there may be a water
space into which the water draining from the mass of coal or mineral in the
receptacle may gravitate and be drawn off by pumping power or gravity as found
desirable by which process the coal may at once be made ready for use for coking
or other purposes in a much drier condition than by any other process at present.
in use.
By the improved apparatus above foreshadowed the whole of the smaller or
fine coal is retained in the receptacle together with the larger coals and the water
draining from the receptacle is in consequence much purer and therefore more

page_text: fitted for subsequent re-use than has hitherto been the case or if not required for
re-washing may be run into any stream without polluting the same.
When sufficiently drained of its water the contents of the receptacle may be
discharged as above described by the opening of a suitably mounted basal door
or valve into wagons or as required.
The mass of coal itself can thus be utilised to act as the filtering medium
whereby not only is a great saving in coal or like mineral and labour effected but a
much purer resultant water is obtained.
Dated this 27th day of March 1895.
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.
Improvements in Means for Filtering Water from Washed Coal or
like Mineral, and for Recovering Coal or like Mineral from such
Water.
We, CHARLES CRAIG, WILLIAM CRAIG and GEORGE KERR CRAIG all of
Sacriston in the County of Durham, Contractors, 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:-
This invention relates to improvements in means for filtering water from washed
coal or like mineral and for recovering coal or like mineral from such water.
For example in the washing of coal it is a common practice after the stone and
dirt have been removed therefrom to allow the washed coal and water to pass away
together and to allow the water remaining in or with the coal to drain away to
filter or other beds where the water is eventually extracted from the fine coal and
allowed to drain to waste in a condition still retaining a quantity of fine coal in
suspension.
By this arrangement it is found in practice that a material waste of coal is
continually taking place and considerable cost is also involved in relifting the
filtered small coal from the beds for use in certain kinds of work where only an
inferior class of coal is required.
Now by our invention we interpose between the washing machine and the wagons
or the like into which the mineral is intended to be loaded a filtering or draining
apparatus which may consist of a receptacle of suitable capacity and form and
into which the washed coal or mineral and water (or as much of the latter as has
not gone away with the dirt already extracted during the washing process) are
discharged.
The receptacle may be fitted internally with a central vertical or other shaft
fitted with central vertical or other arms or blades and with one or more
horizontal or other arms or scraper devices the whole being adapted to revolve
when required by suitable toothed or other gearing mounted above or in connection
with the receptacle.
The horizontal arms or scraper device may in certain cases be fitted and counter-
balanced so as to be adapted to slide up and down the central shaft the object of
this contrivance being to relieve or open the centre of the mass of coal or mineral
so as to concentrate it towards the basal opening or outlet in the receptacle.
"
The receptacle may be furnished at or near its base with a cloth or strainer
device or with two or more such devices between any two of which if found
desirable a certain thickness of filtering material such as small coal, coke " "breeze
or equivalent material may be interposed by which the coal may at once be made
ready for use for coking or other purposes in a much drier condition than by any
other process at present in use.

page_text: By the improved apparatus above foreshadowed the whole of the smaller or fine
coal is retained in the receptacle together with the larger coals thus abolishing the
necessity for sludge or recovery or silt ponds and the water draining from the
receptacle is in consequence much purer and therefore more fitted for subsequent
re-use than has hitherto been the case or if not required for re-washing may be
run into any stream without polluting the same.
When sufficiently drained of its water the contents of the receptacle may be
discharged as above described by the opening of a suitably mounted basal door or
valve into wagons or as required.
The mass of coal itself can thus be utilised to act as the filtering medium.
whereby not only is a great saving in coal or like mineral and labour effected but a
much purer resultant water is obtained.
We will fully describe our invention with reference to the accompanying
drawings in which Figure 1 shows a vertical sectional elevation and Figure 2 a
plan view of the filter and in the following description like marks of reference.
indicate like parts.
Referring to the drawings a is the filtering vessel fitted with a central basal
opening controlled by a door D. In the cross-piece 4 we mount the vertical
screw spindle 5 whose upper end is carried as shown in a bearing at 6 and we
further arrange certain vertical arms 7 connected to the said spindle 5 and
adapted to rotate therewith as shown. There is also mounted on the spindle 5.
and connected with two of the said arms 7 a sliding beam 8 (fitted with a nut to
screwed spindle 5) carrying harrows 9. The bottom of the filter is arranged with a
series of radial joists or bearers 10 between which is packed coke-breeze 11 or
small coke or coal as above described to the depth of about one foot for a filter
having a capacity of 50 to 60 tons and on the bearers we lay and secure a covering
of for example strong brass wire gauze 12. Outlet pipes 13 are fitted to the filter
bottom and controlled by cocks.
When the washed coal is discharged into the filtering tub a and as soon as there
is a depth of about 2 feet of such coal in the filter then the cocks of the outlet.
pipes 13 can be opened and we find in practice that they then can be allowed to remain
open and the water discharging through them will be found to be comparatively
speaking quite clear thus showing that the fine coal previously held in suspension
in the water has been retained in the filter. As soon as the filtering tub is
sufficiently full of coal from which the water has been withdrawn and cleansed by
passing through the mass of coal and through the stratum of small coke then the
door D can be opened and the spindle 5 caused to revolve by bevel or other
friction and clutch gearing or as shown. The coal can thus pass direct into wagons
and the revolving apparatus always keeps the basal opening clear thus preventing
clogging and allowing a free discharge. The harrows arranged as described also
tend to draw the coal towards the central outlet and the harrow beam is allowed to
descend by the action of screwed spindle 5 with or upon the surface of the coal
until the filtering tub a is emptied when by reversing the motion of the screwed
spindle the harrow beam can be again lifted to its former position.
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 :-
1. The improved method of filtering water from washed coal or like mineral
and for recovering coal or like mineral from such water consisting in the use of a
filtering tub into which the washed coal is discharged and there allowed to drain
itself of its water the effluent water having first been caused to give up its fine or
floating coal which is thus retained in the filter whereby not only is a great saving
in actual coal or mineral effected but the discharged water is cleansed of all
impurities the several parts for effecting the several purposes being arranged
disposed or adapted for work and use substantially as herein set forth.
2. The improved method of filtering water from washed coal or like mineral

page_text: and for recovering coal or like mineral from such water consisting in the general
arrangement or combination of parts forming improved recovering filtering and
cleansing apparatus substantially as herein set forth.
Dated this 28th day of December 1895.
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.