An Improved Centrifugal Crushing Mill.
Year: 1895

page_text: Date of Application, 26th Jan., 1595-Accepted, 2nd Mar., 1895
An Improved Centrifugal Crushing Mill.
I RICHARD SAUERBREY, of Stassfurt, Germany, 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 centrifugal crushing mill of this present invention is remarkable for the
concentration of the effective or working parts upon the smallest possible compass.
The material to be reduced is not subjected to a grinding or triturating action,
but is turned into flour or dust only by the effect of blows caused by centrifugal
force.
There are quite a number of similar mills known, but this present machine shows
peculiarities of its own, which exert important and favorable influence upon the
process of reducing. In the first place the steplike arrangement of the rotating
body or cone and correspondingly for the stationary bell or mantle offers the
advantage that as the material fed is being beaten smaller and smaller it is being
subjected to the increasing centrifugal force.
The turntable plates, I, II, III, IV, being provided with ribs, a ventilating
effect is being attained, and by fitting elevated rings around the periphery of these
plates, the effect of the blows is still increased.
As appears from the accompanying drawings the principal improvement in this
machine consists in the arrangement of a rotating body b of steplike circular
plates I, II, III, IV, etc., provided with raised edges d and ribs c. The ribs c when
body b is rotating cause a strong current of air, since they act like the wings of a
fan. This draft carries the material, fed through adjustable hopper a downward
in the direction of arrow C Fig. 3. During its passage it is thrown back upon
the rotating plates from or by the corresponding parts of the mantle, where by the
centrifugal force it is driven again towards edges d. Here it overcomes the
friction between the material to be ground and the plates, and is now thrown
onward in the direction of arrow A. The result of the two components A and C
is the actual direction of arrow B. Thus the action goes on until the material
finally gets to ring attached to b, and consequently rotating with b whence with
the assistance of the existing current of air and a striker not shown in the drawing,
it is passed out of the machine at outlet g, Fig. 2.
Thus the material with this machine is not ground in the usual way nor knocked
about by pins, but by its living force, vis viva, it is being thrown against the
mantle and thus broken up.
The current of air produced by the rotation of the body b, serves at the same
time for. cooling the material, which otherwise doubtless would get hot, in
consequence of the transformation of vis viva into 'heat, caused by the sudden
destruction of the former.
The continually decreasing dead weight of the individual particles of the material
is being balanced by the lower steps increasing in size and the consequently
greater centrifugal force so that the momentum of the vis vica approximately
remains the same.
The ribs e will also help to reduce the material, since during its descent it will
continually receive blows as it knocks against these ribs.
The main purpose of ribs c is the creation of a current of air, while the reduction
by the catching and the knocking about and the collisions of the material by and
with these ribs, is only a secondary consideration.

page_text: The ring-like edges, D hold the material back until finally the centrifugal force
overcomes the resistance, when the material is thrown off with so much greater
force. Besides this edge gives to the material a peculiar direction, so that it cannot
be carried off immediately by the strong current of air.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A centrifugal crushing mill, in which the material, by means of quickly rotating
steplike troughs, is being thrown, in consequence of the produced centrifugal force,
against the grinding surfaces e, on the inside of a conical mantle, while at
the same it is being cooled by the current of air, produced by the raylike
ribs e placed in the interior of troughs b, substantially as and for the purposes
set forth.
Dated this 26th day of January 1895.
HUGHES, SON & Co.,
38, Chancery Lane, London, W.C., Agents for the Applicant.