Improvements in Mills for Pulverizing or Pulverizing and Mixing Cements and other Substances.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Mills for Pulverizing or Pulverizing and Mixing
Cements and other Substances.
I, MEYER JOSEPH DAVIDSEN, 144, Boulevard de la Villette, Paris, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
Ball mills have been constructed comprising a horizontal or approximately
horizontal internally smooth chamber of cylindrical or other shape able to rotate
about its axis and adapted to be rotated by suitable means without the use of
an internally arranged central shaft, such chamber being provided with loose
balls and the arrangement being such that cement or other material to be
treated can be fed into the chamber at or near the central portion of one end
in a practically continuous manner, and treated material be discharged in a prac-
tically continuous manner at the other end. Mills of this kind are described
in the Specification of a former Patent granted to me the 14th November 1893,
No. 21,708.
Now the object of my present invention is to adapt mills of the said kind for
effecting pulverization more rapidly and also for dealing more advantageously,
with comparatively soft substances such, for example, as coal.
A mill according to my present invention is constructed with two
or more pulverizing op pulverizing and mixing chambers (hereafter
called for distinction main chambers) separated by divisions, each of
which comprises all annularly arranged series of cells or pockets
having inlet openings near the wall of the main chamber in rear
thereof so as to receive material therefrom and discharge openings located nearer
the common axis of the series of main chambers and adapted to discharge into
the main chamber next in advance, which discharge openings are provided or
not with valves that may be ball valves or valves of other suitable kind, the
arrangement being such that material to be treated having been fed into say
the first main chamber at or near the central portion of its one end, will gradually
accumulate and be treated by the balls therein as the series of main chambers
is rotated, the material in the first chamber extending to its highest level at or
near the inlet to that chamber and being of gradually decreasing depth towards
the exit end of the same chamber, whence it enters those pockets or cells of the
corresponding division or partition which, for the time being, are lowermost,
so that, as rotation of the chambers continues, the material in such pockets is
carried up in them until they reach or approach their horizontal positions, and
that, whilst the pockets or cells are travelling through the higher portion of
their course, they will discharge their contents into the succeeding main chamber
and so on from chamber to chamber.
The discharge from the final main chamber of the series may take place in a
direct manner through holes in its annular wall, or in its end wall, or both, or

page_text: its end may be constructed with a series of cells or pockets adapted to give a
central discharge, if found for any reason desirable.
The balls in each main chamber may be of a different size to those in the other
main chambers, each of which may be charged with balls up to or nearly the
level of their inlet openings; the balls may conveniently be of decreasing size
as the material becomes finer.
The number of main chambers and pockets, the method of mounting and
imparting rotary motion to the chambers and other details may be more or less
varied to suit circumstances.
Improvements in Mills for Pulverizing or Pulverizing and Mixing
Cements and other Substances.
I, MEYER JOSEPH DAVIDSEN, 144, Boulevard de la Villette, Paris, Civil
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:-
-
Ball mills have been constructed comprising a horizontal or approximately
horizontal internally smooth chamber of cylindrical or other shape able to rotate
about its axis and adapted to be rotated by suitable means without the use of
an internally arranged central shaft, such chamber being provided with loose
balls and the arrangement being such that cement or other material to be
treated can be fed into the chamber at or near the central portion of one end
in a practically continuous manner, and treated material be discharged in a prac-
tically continuous manner at the other end. Mills of this kind are described
in the Specification of a former Patent granted to me the 14th November 1893,
No. 21,708.
Now the object of my present invention is to adapt mills of the said kind for
effecting pulverization more rapidly and also for dealing more advantageously
with substances which are comparatively soft and are introduced into the mill
in relatively large pieces such, for example, as coal.
Referring to the accompanying illustrative drawings, Fig. 1 is a longitudinal
section of a mill according to my present invention; 1 is a cylindrical vessel
provided with trunnions 2, 2 resting in bearings 3 and adapted to be rotated
by suitable mechanism engaging with the toothed wheel 4. The
vessel 1 is constructed with two or more pulverizing or pulverizing
and mixing chambers (hereinafter called for distinction main chambers); in
the example there are three such main chambers marked 5, 5º, 5º separated
by divisions or partitions 6, 6" each of which comprises an annularly arranged
series of cells or pockets 7 having inlet openings S near the wall of the main
chamber in rear thereof so as to receive material therefrom, and discharge
openings 9 located nearer the common axis of the series of main chambers and
adapted to discharge into the main chamber next in advance. Thus the cells
or pockets 7 of the division 6 receive material from the main chamber 5 and
"

page_text: discharge it into the main chamber 5, whence it passes into the cells or pockets
of the division G" to be discharged therefrom into the main chamber 5.
Fig. 2 is a transverse section of the division 6 to an enlarged scale and Fig. 3
is a section on the line a Fig. 2.
In this construction of division, the discharge openings 7
are provided with
ball valves 10 arranged on the discharge side thereof and retained in position
by means of cross bars 11. The central portion of the division is formed by a
truncated conical plate 12 whose convex surface extends into the main chamber 5"
next in advance. Material to be treated having been fed into, say, the first main
chamber, at or near the central portion of its one end, for instance, through the
trunnion 2 by a screw conveyor 13, will gradually accumulate and be treated
by the balls therein as the vessel 1 is rotated, the material in the chamber 5
extending to its highest level at or near the trunnion 2 which forms the inlet
to that chamber and being of gradually decreasing depth towards the exit end
of the same chamber, whence it enters those pockets or cells 7 of the division
or partition 6 which, for the time being, are lowermost, so that, as rotation of
the vessel I continues, the material in such pockets is carried up in them until
they reach or approach their horizontal positions, and that, whilst the pockets -
or cells are travelling through the higher portion of their course, the ball
valves 10 will move away from the openings 9 and the contents of the cells or
pockets will be discharged therefrom and directed forward by the plate 12 into
the succeeding main chamber 5" and so on from chamber to chamber. Although
ball valves are shown in the division or partition 6, other forms of valves may
be provided. Or valves may be dispensed with as in the construction of division
or partition shown at 6" and illustrated to a larger scale in Figs. 4 and 5 which
are respectively a transverse section and section on the line 66 Fig. 4. The
discharge opening is in this construction fitted with a grid 14 and a separate
channel or passage 15 leads therefrom over the plate 12 to the next main
chamber.
The several partitions or divisions of a mill may be constructed in either of the
ways illustrated, or some may be constructed as shown in Figs. 2 and 3 and
some as shown in Figs. 4 and 5 as required. The discharge from the final main
chamber 5 of the series may take place in a direct manner through holes 16
in its annular wall, as shown, or through holes in its end wall, or both; or its
end may be constructed with a series of cells or pockets adapted to give a central
discharge, if found for any reason desirable. 17 is the final discharge shoot of
the mill.
The balls in each main chamber may be of a different size to those in the other
main chambers, each of which may be charged with balls up to or nearly to
the level of their uppermost inlet openings; the dotted lines in Fig. 1 indicate
approximately the levels to which the chambers may be charged with balls
which may conveniently be of decreasing size as the material becomes finer.
The number of main chambers and pockets, the method of mounting and
imparting rotary motion to the chambers and other details may be more or less
varied to suit circumstances.
Having now particularly described and ascertained the nature of the said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
1. A ball mill wherein an approximately horizontal tubular vessel able to
rotate about its axis is divided into two or more main ball-containing chambers
by partitions or divisions each of which is formed with cells or pockets adapted,
during rotation, to receive material from the lower portion of the rearward main
chamber and to discharge it at a higher level into the next main chamber in
advance, substantially as described.
2. A ball mill of the kind specified in Claim 1 wherein each partition or

page_text: division comprises an 'annularly arranged series of cells or pockets having lateral
inlet openings near the wall of the main chamber in rear thereof and openings
in their internal walls through which the material is discharged at a higher level
into the next main chamber in advance, substantially as described.
3. Ball mills constructed, arranged and operating substantially as described
and illustrated in Fig. 1, the partitions or divisions being constructed as shown
in and decribed with reference to Figs. 2 and 3, or Figs. 4 and 5 respectively
of the accompanying illustrative drawings.
Dated this 16th day of May 1899.
For the Applicant,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C.,
Chartered Patent Agent.