Improvements in Ball Grinding Mills.
Year: 1894

page_text: Date of Application, 26th Jan., 1894
Complete Specification Left, 17th Oct., 1894-Accepted, 17th Nov., 1894
PROVISIONAL SPECIFICATION.
Improvements in Ball Grinding Mills.
I, JACOB PFEIFFER, of Kaiserslauten, Bavaria, Germany, Manufacturer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to an improved construction of ball grinding mills as I will
describe with reference to the accompanying drawing, in which
Fig. 1 shews a vertical section, Fig. 2 a plan, and Fig. 3 an enlarged detail.
The steel balls c are driven round by arms d'in a hollowed grinding ring e and in
being forced by centrifugal action against this ring, they effect the grinding of the
material introduced through a fixed hopper g and a cone f fixed to and rotating
with the arms d.
Above the grinding ring e are two concentric casings h and i of which i is
completely closed, while is open at top, leaving a space between it and the casing i.
In this space is arranged a fan k carried by arms fixed to the cone f and revolving
with the same.
When the material is fed in through the hopper g it is ground by the balls, the
finely ground material being drawn out of the grinding ring and through the space
within casing by the air currents produced by the fan as indicated by the arrows,
and it is propelled thereby into the casing i.
The ground material collecting in this casing is conveyed to the discharge
opening n by the scrapers m fixed to the fan k, and is conveyed thence to wherever
required.
By suitably determining the speed of the mill, any desired degree of fineness of
the product may be obtained, without requiring to use sieves, or to separate
middlings for conveying the same to other grinding apparatus.
By the very compact form of the apparatus, space is very effectually economised.
A farther advantage of the construction consists in that both the material and the
grinding ring are kept very cool by the action of the fan, and consequently are
preserved from deterioration.
In order to reduce the friction and wear between the carrier arms d and the
balls c to a minimum the arms are fitted with steel plates o which contain hard
conical plugs p (or balls might be used) projecting from the plates and serving to
drive the balls round, as shewn at Fig. 3.
The fan k can also be driven independently of the mill, so as to render its speed
independent of that of the arms d driving the balls; it may also be arranged
entirely separate from the grinding mill.
Dated this 26th day of January 1894.
ABEL & IMRAY,
Agents for the Applicant.
VUMI DID OF MUIFICATION.
Improvements in Ball Grinding Mills.
I, JACOB PFEIFFER, of Kaiserslauten, Bavaria, Germany, Manufacturer, 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:-
My invention relates to an improved construction of ball grinding mills as I will
Pine 81

page_text: describe with reference to the drawings accompanying my Provisional Specification
in which
Fig. 1 shews a vertical section Fig. 2 a plan, and Fig. 3 an enlarged detail.
The steel balls c are driven round by arms d in a hollowed grinding ring e and
in being forced by centrifugal action against this ring, they effect the grinding of
the material introduced through a fixed hopper g and a cone f fixed to and rotating
with the arms d.
Above the grinding ring e are two concentric casings and i of which i is
completely closed, while his open at top leaving a space between it and the casing i.
In this space is arranged a fan k carried by arms fixed to the cone f and revolving
with the same.
When the material is fed in through the hopper it is ground by the balls, the
finely ground material being drawn out of the grinding ring and through the space
within casing by the air currents produced by the fan, as indicated by the arrows,
and it is propelled thereby into the casing i.
The ground material collecting in this casing is conveyed to the discharge
opening n by the scrapers m fixed to the fan k, and is conveyed thence to wherever
required.
By suitably determining the speed of the mill, any desired degree of fineness of
the product may be obtained, without requiring to use sieves, or to separate
middlings for conveying the same to other grinding apparatus.
By the very compact form of the apparatus, space is very effectually economised.
A farther advantage of the construction consists in that both the material and
the grinding ring are kept very cool by the action of the fan, and consequently are
preserved from deterioration.
In order to reduce the friction and wear between the carrier arms d and the
balls c to a minimum, the arms are fitted with steel plates o which contain hard
conical plugs p (or balls might be used) projecting from the plates and serving to
drive the balls round, as shewn at Fig. 3.
The fan k can also be driven independently of the mill, so as to render its speed
independent of that of the arms d driving the balls; it may also be arranged
entirely separate from the grinding mill.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The combination with a ball grinding mill of a fan in such manner that the
material ground to a fine powder is taken up by the current of air produced by a
fan either combined directly with or separate from the mill and is carried thereby
into a collecting chamber, the said current of air having at the same time the effect
of cooling both the material and the grinding mill, substantially as described.
2. In ball grinding mills such as are referred to in the first claim, constructing
the arms that drive round the balls with driving surfaces composed of hard plugs
or balls, substantially as described.
Dated this 17th f
1004
ABEL & IMRAY,
Agents for the Applicant.