Improvements in the Construction of Magnetic Separators.
Year: 1890

page_text: Date of Application, 31st Oct., 1890
Complete Specification Left, 31st July, 1891-Accepted, 12th Sept., 1891
. Improvements in the Construction of Magnetic Separators.
We, CLAUDE WILLIAM ATKINSON, Civil Engineer, and LLEWELYN BIRCHALL
ATKINSON, of the firm of W. T. Goolden & Co., Electrical Engineers, Civil
Engineer, both of Woodfield Works, Harrow Road, London, W., in the County of
Middlesex, do hereby declare the nature of this invention to be as follows:-
.
This invention relates to improvements in the construction of magnetic separators
formed of a revolving drum or chamber.
The improvements consist in the construction of a drum of cast or wrought iron, or
other suitable magnetic material forming the magnetic connecting yokes for a series
of poles internally placed, surrounded by coils of insulated wire for the purpose of
magnetising them.
The drum may be carried and revolved either upon an axis, to which it is secured
by radial arms or,.by.forming on the external surface, flanges, or grooves riding on
corresponding flanged or grooved rollers.
The internal magnet cores may be constructed in several ways, the methods we
prefer being in the case of a cast iron cylinder to cast them in one piece with the
external shell, and to provide them with separate pole pieces secured by bolts, or
otherwise, or in the case of a wrought iron shell, to use separate cores bolted to the
shell, or the shell itself in place of being continuous may be built of a series.of
segmental plates with flanges or angles which themselves form the internal poles.
To provide for the continuous traverse through the separator of the material
being dealt with, we arrange either that the whole cylinder has its axial line
inclined to the horizontal or its equivalent, a conical internal surface with horizontal
axis thus relying upon gravitation to produce the traverse.
These methods may be adopted when it is necessary with the internal cylindrical
surface smooth.
In place of these methods, or in addition to them we may use means to provide
internal projections forming parts of a helical surface, or separate mechanical feeds
may be adopted.
In order to provide for the removal of the magnetic material attracted to and
carried forward by the magnetic poles, arrangements are provided for demagnetising
the cores in turn during a part of the revolution.
This is effected by divided collecting rings, carried by the drum, which serve
in combination with bushes pressing on them to distribute the current to the
active magnetic coils.
In order to diminish the sparking and burning arising from the interruption, or
variation of the electric current, the current may, instead of being abruptly varied,
be varied gradually by the use of a succession of brushes having arranged between
them suitably proportioned resistances.
We prefer that the cores which are demagnetised should be those at or near the
highest point in the revolution and a trough, or shoot which if necessary, may be
kept in vibration is provided to catch the falling material.
In dealing with substances containing iron or magnetic material in a fine state of
division it is desirable to provide brushes or scrapers to ensure its complete
removal.
In the case where it is desirable that the interior of the cylinder should be
smooth, or nearly so, the spaces between the magnetic poles may be filled in either
with brass or non-magnetic material or with wood or cement these being covered

page_text: if necessary, by a thin lining of steel, care being taken that the thickness is not so
great as to impair the magnetic efficiency.
Dated this 31st day of October 1890.
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
LLEWELYN
Improvements in the Construction of Magnetic Separators.
We, CLAUDE WILLIAM ATKINSON, Civil Engineer, and
BIRCHALL ATKINSON, of the firm of W. T. Goolden & Co., Electrical Engineers,
Civil Engineer, both of Woodfield Works, Harrow Road, London W., in the
County of Middlesex, 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 the construction of magnetic separators
formed of a revolving drum or chamber.
The improvements consist in the construction of a drum of cast or wrought iron
or other suitable magnetic material forming the magnetic connecting yokes for a
series of poles internally placed, surrounded by coils of insulated wire for the
purpose of magnetising them.
The drum may be carried and revolved either upon an axis to which it is secured
by radial arms or by forming on their external surface flanges or grooves riding on
corresponding rollers one or all of which are driven by power so as to revolve the
barrel which however may be done by an independent geared wheel.
The internal magnet cores may be constructed in several ways, the methods we
prefer being in the case of a cast iron cylinder to cast them in one piece with the
external shell and to provide them with separate pole pieces secured by bolts or
otherwise or, in the case of a wrought iron shell to use separate cores bolted
to the shell, or the shell itself in place of being continuous may be built of a series
of segmental plates with flanges or angles which themselves form the internal poles.
To provide for the continuous traverse through the separator of the material
being dealt with, we arrange either that the whole cylinder has. its axial line
inclined to the horizontal, or its equivalent, a conical internal surface with horizontal
axis, thus relying upon gravitation to produce the traverse.
These methods may be adopted, where it is necessary, with the internal
cylindrical surface smooth.
In place of these methods, or in addition to them we may use means to provide
internal projections forming parts of a helical or spiral feeding surface; or separate
incchanical feeds may be adopted.
In order to provide for the removal of the magnetic material attracted to and
carried forward by the magnetic poles, arrangements are provided for demagnetising
the cores in turn during a part of the revolution.
This is effected by divided collecting rings, carried by the drum, which serve in
combination with brushes pressing on them to distribute the current to the active
magnetic coils.
In order to diminish the sparking and burning arising from the interruption or
variation of the electric current, the current may, instead of being abruptly varied
be varied gradually by the use of a succession of brushes having arranged between
them suitably proportioned resistances.
We prefer that the cores which are demagnetised should be those at or near the
highest point in the revolution and a trough or shoot, which if necessary may be
kept in vibration, is provided to catch the falling material.
In dealing with substances containing iron or magnetic material, in a fine
state of division, it is desirable to provide brushes or scrapers to ensure its complete
removal.

page_text: In the case where it is desirable that the interior of the cylinder should be
smooth, or nearly so, the spaces between the magnetic poles may be filled in, either
with brass or non-magnetic material, or with wood or cement, these being covered
if necessary by a thin lining of steel, care being taken that the thickness is not so
great as to impair the magnetic efficiency.
And in order that our invention may be the better understood we now proceed
to describe the same reference being had to the drawings hereto annexed and to
the letters and figures marked thereon.
Fig. 1. shews a side sectional elevation of our improved separator.
Fig. 2. shews an end sectional clevation.
Fig. 3 is a diagram of electrical connections and
Fig. 4 shews a detached sectional detail where the surface of the barrel is formed
into pockets.
a is the drum or barrel of magnetic material: are the poles placed around
the interior periphery of the barrel ce are the coils of copper wire conveying the
currents to magnetize them: dd are the rollers supporting the barrel and upon
which the latter revolves.
The arrangement of electrical circuits is shewn in Fig. 3 and are connected in
Figs. 2 & 4 to give the respective polarities indicated by the letters and s. The
coils are in parallel and one end of each coil is connected to e, a continuous
collector ring to which the current passes from any generator by the brushes f. f.
The other ends of the coils are connected in turn to the divided ring h, one to each
division, and brushes g. g. are provided pressing on this divided ring in such a
manner that each coil is always under one or more of them during the upward
revolution. An additional brush is provided, and connected through a resistance
coil either to the circuit connected to for to the circuit connected with J.
I
In the former case as shewn in the diagram, the coil on leaving the last brush
has its ends connected through the resistance which allows the current to die
down with little spark. In the latter case when connected to y the result is to
diminish the current before breaking with a similar object in view.
m is the feeding shoot and the tray or shoot arranged to catch the iron as it is
dropped from the poles when they are de-magnetised.
The outer surface of the barrel instead of being a smooth surface may be formed
into a series of pockets containing the magnetic poles & coils Fig. 4, so that the
surfaces of the said poles come level with the interior intermediate parts of the
internal surface of the barrel which thus form additional poles without any
additional magnetising coils.
The space surrounding the coils may be filled with wood or other material as
may be convenient.
In the annexed drawings the pole pieces of the magnets are shown as raised
ridges extending along the floor or inside of the barrel, parallel to the axis of the
same, the feed of the material being entirely by gravity down the coned side of the
barrel. We may however set out the said ridge pole pieces in spiral lines to
the axis of the barrel & turning back from the direction of rotation, so that were
the barrel parallel & horizontal, the non magnetic material as raised by the rotation
of the said ridges with the barrel, would tend to slide by gravity down the said
spiral or sloping ridges towards the mouth of the barrel & be thus discharged.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is:-
1st. In a magnetic separator a hollow revolving cylinder of magnetic material
having internal polar projections magnetized during part of a rotation by an
electric current supplied through a commutator & brushes, the barrel being
provided with
a collecting tray, & feed hopper or shoot substantially as
2nd. In such a magnetic separator the arrangement of the magnet poles in a
described.

page_text: spiral pathway for effecting the continuous feed of the material substantially as
described.
3rd. In such a magnetic separator the arrangement of commutator.or collecting
rings, brushes and connections therewith and resistance.coils therein, substantially
as described.
4th. In such a magnetic separator the arrangement of the drum surface with
pockets formed therein containing the magnetic poles & coils substantially.as
described.
1 C... 1901
FELL & WILDING,
1, Queen Victoria Street, London, E.C., Agents for the Applicants.