Improvements in Rotary Mills for Grinding or Pulverising.
Year: 1899

page_text: Date of Application, 1st June, 1899-Accepted, 5th Aug., 1899
COMPLETE SPECIFICATION.
Improvements in Rotary Mills for Grinding or Pulverising.
I, GEORGE STOCKHAM EMERICK, of No. 703, Lippincott Building, in the City
and County of Philadelphia, State of Pennsylvania, one of the United States
of America, Mechanical 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:-
My invention relates to rotary mills of the kind in which a rotating cylindrical
casing is divided by vertical partitions into compartments, each containing pebbles
or small balls which are caused by the rotation of the casing to pulverize material
as it passes successively through the compartments.
The object of my invention is such an arangement of the machine that the
material in passing into each compartment is introduced to the action of the balls
at or near the inner circumference of the casing, and rises as it is ground between
the balls, toward the centre of the compartment, to be re-introduced in the same
manner into the next compartment; the movement of the material in process of
grinding being always from the circumference toward the centre of the casing.
I attain this object by the mechanism illustrated in the accompanying
drawings:-
Fig. 1 is a longitudinal section of the mill, Fig. 2 is an end view, Figs. 3 and 4
are respectively an end and a side view of part of the rotating mechanism.
Fig. 5 is a transverse section of the mill on the line 5-5, Fig. 1, showing the
face of a transverse partition and a section of the longitudinal partition.
A is a cylindrical casing having inlet and outlet hollow trunnions B and C
and divided into compartments, F and G, by transverse partitions D and E.
H is a hopper communicating with the inlet trunnion B. The inlet and outlet
trunnions revolve in bearings carried by supports I.
Each partition D is double, consisting of two parts D and D a little distance
apart. The part D has central holes J, and between the circumference of the
part D and the circumference of the part D¹ there is an opening which may be
either a continuous circular slot or separate holes at intervals around the cir-
cumference. The two parts of the partition are attached to one another by
separate studs so that material in passing from one compartment to the next
enters by the central holes J, passes down through the open space within the
partition and passes into the next compartment through the opening or openings
near the circumferences of the partition.
The last partition E has central holes K. The partition L extends lengthwise
through the compartments F, partially dividing the interior of each.
T are tapered rings into which the partitions D are wedged and secured by set
screws U so as to make a tight joint between the partitions and the casing and
at the same time to admit of the removal of the partitions for purposes of
adjustment or repair.
The compartments F contain pebbles or balls of any suitable hard material. The

page_text: relative size of the balls and of the holes in the partitions should be such that the
balls cannot pass through them or enter the interior of the partitions.
As shown in Fig. 2, the wheel N driven by belt on the pulley O gears with N
which gears with N2. The wheels N and N2 drive the shafts P which extend
on either side of and parallel to the casing A, and revolve in bearings R. The
shafts P carry shieve wheels Q, in the grooves of which are engaged rails M,
attached to the circumference of the casing A.
The operation of the rotary mill is as follows: The cylindrical casing A
being caused to rotate by any suitable power, the material to be pulverized is
introduced through the inlet trunion B into the first compartment F. It is here
subjected to the action of the balls or pebbles between which it works upward
toward the centre of the compartment, and passing through the central holes J
into the partition it falls through the space between the parts D and D to
the openings at the circumference of the partition where it passes out into the next
compartment and is again subjected to the action of the balls or pebbles while
working upward between them in the manner above described.
This movement being repeated according to the number of compartments in the
casing A, the material passes through the central holes K in the last partition E
into the compartment G, where it is taken up by projecting ribs V, and guided
to the outlet trunnion C. The course of the material as it passes through the
mill is indicated by arrows in Fig. 1. The longitudinal partition L serves as the
casing rotates, to more completely mix the material with the balls and thus to
increase. their pulverizing efficiency.
I am aware that grinding or pulverizing machines have already been constructed
in which material is ground by balls while passing through successive compart-
ments in a drum shaped casing. I therefore make no general claim to such
machines but,
Having now particularly described and ascertained the nature of this
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
In a rotary hill, a casing having hollow trunnions for inlet and outlet one or
more transverse partitions each consisting of two walls at a little distance apart,
the wall nearest the feed inlet, having central holes and the other wall having
holes near the circumference, so that material passes from the reducing-compart-
ment nearest the feed inlet through the central holes in the first wall then
through the space between the walls and finally through the openings at the
circumference of the second wall into the next reducing compartment substantially
as described.
Dated this 1st day of June 1899