Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to methods of working
friable materials, and, more particularly, it relates to a method
and apparatus for disintegrating materials, for instance, ores
of ferrous and non-ferrous metals.
The invention can be utilized by various industries
where raw materials are worked, e.g. by the mining industry,
metallurgy of ferrous and non-ferrous metals, the chemical
industry, etc.
Processes of crushing the grinding friable materials
and broadly utilized by various industries using raw materials
and working them by various methods in all types of equipment.
Nowadays the most widely utilized technique of
disintegrating or reducing a material is its autogenous reduction
in a confined space, e.g. in a rotating drum. According to this
technique, lumps of the material are lifted in the vessel to a
certain height and allowed to fall back under the action of
gravity so as to cause them to break up.
A whole range of mills has been created, utilizing
this technique.
A disadvantage of the method of autogenous
disintegration of a material in a rotary drum is its inherent
relatively low specific throughput and inadequate efficiency.
This is explained by the fact that the material is to be
lifted to a certain height, so as to supply it with an amount
of energy sufficient for its self-destruction.
There is also known a method of disintegrating a
material
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accelerated in a centrifugal bowl-shaped rotor and directed
against deflection plates effecting its destruction.
However, this method has a number of disadvantages.
Among them is a relatively high energy consumption, and also
excessive wear of the assemblies and components of the structure
which have to withstand impact loads.
The main object of the present invention is to
provide a method of continuous disintegration of a material by
dynamic loads which should increase the intensity and efficiency
of the process.
It is another object of the present invention to
provide an apparatus for dynamic disintegration of a material
which should be of a simple construction and offer high through-
put.
It is also an object of the present invention to
reduce the specific amount of metal in an apparatus for dis-
integrating materials.
It is still another object of the present invention
to provide an apparatus with a relatively low level of noise
produced during operation.
Accordingly, the present invention provides a method
of disintegrating lumped materials into smaller particles,
comprising: continuously feeding into a vertical column a
lumped material which can be reduced by disintegration into
smaller particles; rotating about the axis of said column of
material a lower portion of said column of material having a
configuration of a truncated cone with a velocity gradient
increasing away from the axis and at a maximum rotational speed
remote from said axis to develop an active horizontal, annular
disintegration zone immediately above said lower portion of
the vertical column of material in which lumps of said material
impact each other and disintegrate; and causing disintegrated
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material from said lower portion to flow away outwardly and
upwardly along the periphery of said column to allow continuous
entry of lumped material into said disintegration zone and
disintegrated material into said lower portion, said lumped
material in said column above the level of said disintegration
zone being held from rotation and establishing a pressure head
of said lumped material on the material in said zone.
It is expedient that the circumferential speed at the
periphery of the rotor should be set within a range from 10
to 70 m/s, to provide for dynamic action upon the material in
the active disintegration zone.
It is also expedient that the pressure of the column
of the material at the level of the uppermost surface of the
rotor should be maintained within a range from 0.05 to 0.15 MPa.
The present invention further provides an apparatus
for disintegrating lumped materials into smaller particles,
comprising: means for containing a vertical column of a lumped
material to be disintegrated; a rotatable conical bowl for
receiving and rotating a portion of said column about the axis
thereof, said conical bowl being provided with vertical partitions
forming a plurality of chambers in the bowl; a zone immediately
above the level of said conical bowl in which a portion of the
column entrained by the portion in the bowl is free to rotate
and in which lumps of the material impact each other causing
them to disintegrate; and means for preventing the lumped
material above the level of said zone from rotating.
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It is desirable that the sections of the rotor should
be defined by vertical partitions providing for acceleration of the
material.
It is further desirable that an annular conical lug
should be provided on the housing about the periphery of the
active disintegration zone.
The apparatus of the abovespecified general structure
provides for intense disintegration of a material with minimum
energy consumption.
The essence of the invention is, as follows. The
material is continuously fed into the apparatus of which the
rotoris rotatedby the drlve means and which rotates, inits turn, the
lower portion of a cylindrical vertical column of the material
confined in the apparatus.
The material in the conical rotor is acted upon by
centrifugal forces of which the value is determined by the
angular speed, the mass of an individual lump and the distance
from the axis of rotation, i.e.
C = m ~2- r, wherein
C is a centrifugal force acting upon an individual lump of the
material, having the mass "m" and rotated at an angular speed
"~" at the distance "r" from the axis of rotation.
With the "m" and "r" values being constant, the value
of the centrifugal force acting upon an individual lump is
proportional to the square of the angular speed of the rotor, its
vertical component equalling:
C tg~ ,
wherein " ~" is the angle defined by the rotor wall and a
horizontal plane. With ~ = 45, the vertical component of the
centrifugal force is numerically equal to its absolute value.
The angular speed of rotation of the rotor is set so that
the pressure of the vertical component of the centrifugal source
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at the external wall of the rotor exceeds the pressure of the
column confined in the apparatus to ensure permanent replacement
of the material in the active zone.
The dynamic action is exerted upon the material in the
active zone by the rotating rotor which transmits pulses of force
to lumps of the material moving at different speeds. Lumps of
the material, coming from the lower portion of the column into the
sections of the rotor, are accelerated by the vertical partitions
of the rotor and sent into the active zone. The lumps have a
kinetic energy equalling mw2, wherein m is the mass of a lump,
and w is its circumferential speed equalling the product of the
angular speed of the rotor by the radius of rotation of the lump.
Since the lump driven by the centrifugal force into
the active zone encounters therein the bulk of the material, it
expands its kinetic energy on destruction of this material and
delivering thereto an effort of force resulting in the material
moving in the active zone.
Since the centrifugal force acting upon the material
within the rotor is directly proportional to the radius of rota-
tion, its minimum value is adjacent to the axis of rotation, and
the maximum value is next to the periphery of the rotor. There-
fore, the particles and lumps of ore are ousted away from the
axis of rotation towards the periphery of the rotor and are
lifted therein, whereby continuous renewal of the material in
the active disintegration zone takes place.
The material disintegration duty in the active zone is
defined by gradient of speed of the material in this active zone
and by the pressure thereupon of the column of the material in
the apparatus.
The circumferential speed at the periphery of the rotor
is preferably set within a range from 10 to 70 m/s, whereby it
- is ensured that the material is dynamically acted upon in the
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active disintegration zone. The optimum value of the circum-
ferential speed for a material with given physical and mechanical
properties is selected on the basis of test data obtained by
experimenting with the parameters of the process.
The pressure of the material column at the level of
the uppermost plane at the rotor is preferably maintained within
a range from 0.05 to 0.15 MPa, which corresponds to a 2.5 to 7.5 m
heiaht of the column of a material of 2-103 kg/m3 specific den-
sity.
When the material is perticularly weak, the lower limit
of the pressure may be lowered to 0.02 MPa.
Thus, the presently disclosed invention enhances the
efficiency of the process of disintegration of a material, while
at the same time substantially reducing the specific energy con-
sumption, owing to the material having applied thereto intense
dynamic loads transmitted by the particles and lumps of the
material to one another.
Furthermore, the specific consumption of steel is like-
wsie reduced, devoid as the apparatus performing the method is of
grinding bodies and armour plates, to say nothing of the better
working conditions of the components of the structure, engaged
by the material being disintegrated.
Moreover, the amount of metal in the construction of the
disintegrating apparatus is reduced, and the driving pattern
thereof is simplified, which also enhances the efficiency of the
process.
Worth mentioning is also the relatively low level of
noise produced by the operating apparatus in accordance with
the invention.
Other objects and advantages of the present invention
will become apparent from the following detailed description of the
performance of the herein disclosed method by an apparatus for
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disintegrating a material, with reference being had to the
accompanying drawings, wherein: ;
~ IG. 1 illustrates the principle of disintegration of a
material, in accordance with the invention;
FIG. 2 is a longitudinal sectional view of the
apparatus for disintegrating a material, embodying the invention; --
FIG. 3 is a sectional view taken on line III-III of
FIG. 2.
Referring now to the drawings, the apparatus (FIGS. 2
. .
and 3) comprises a vertical cylindrical steel housing 1 concen-
trically and coaxially accommodating therein a shaft 2 journalled
in bearing assemblies 3 and 4. The shaft 2 has mounted thereon
a bowl-shaped rotor 5 shaped as a truncated conè. The internal
space of the rotor 5 is divided into sections by vertical
.. ~ :
partitions 6. In the lower portion of each section there is
~;~ provided an aperture i for feeding therethrough a pressurized ~
; carrier fluid (e.g. a liquid or gas) from a container 8 into ~ ;
~ ~ the respective section of the rotor 5. Mounted above the rotor
-`~ 5 concentrically with the shaft 2 is a hollow cylinder 11 inter-
- 20 connected with the housing 1 by vertical partitions 12 dividing
... .
the working space of the housing 1 into a plurality of adjoining
chambers. The uppermost end of the shaft 2 is connected by means
of a coupling 9 with a`drive 10 adapted to rotate the rotor 5.
.i , ,.~
The rotor 5 is so arranged with respect of the partltions 12 of
the housing 1, that a zone "b" is left therebetween for active
- disintegration of~the material. Secured to the housing 1 about
the periphery of this active disintegration zone is a conical lug
i~; 13 protecting the topmost exposed surface of the rotor from engage-
- ment with lumps of the material being disintegrated.
The apparatus operates, as follows: the rotor 5 is put
. .
in rotation by the drive motor, and the material to be disintegra-
ted is continuously fed into the working space of the housing 1
~"''
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via a feed pipe 14, the material including both relatively big
lumps and small particles. The greater portion of the working
space of the housing 1 is thus permanently filled with the
material confined in a cylindrical vertical column continuously
replenished by the feed means (not shown), and continuously dis-
charged via the delivery passage 15 in the form of either a pulp
or a fluidized mass.
In the active disintegration zone "b" defined intermediate
the topmost plane of the rotor 5 and the vertical partitions 12
of the housing 1 there takes place intense crushing and disin-
tegration of the material, resulting from swift relative motion
of layers and lumps striking one another and moving with respect
of one another.
This actively disintegrated layer is permanently re-
newed, since the action of the centrifugal forces upon its
peripheral zone overcomes the weight of the column and lifts the
material therein, while the innermost portions of the active
layer descent to fill in the spaces evacuated in the sections of
the rotating rotor. Disintegrated particles of the material
are taken up by the ascending flow of the carrier fluid and are
discharged from the working space of the apparatus either as a
liquid suspension or pulp, or a gas-fluidized mass.
The rate of the discharge of the material is inter-
dependent with its feed rate, so that the height of the material
column in the working space of the apparatus is maintained
practically at the same level, pre-set in accordance with the
required conditions of the process.
To provide for continuous circulation of the material
and for continuous renewal of the active layer, the upward
pressure produced by the centrifugal action at the periphery
of the bowl of the rotor should be higher than the downward
pressure of the vertical column of the material, which is ensured
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by selecting an appropriate angular speed of the rotor 5.
In the herein disclosed apparatus the major portion
of the supplied energy is spent on disintegrating the material
in the active zone intermediate the rotating rotor and the
vertical partitions of the housing. Consequently, the consump-
tion of energy by disintegration of a material is substantially
lower than in hitherto known ore mills wherein considerable
amounts of energy are spent on lifting, moving and deforming
permanent grinding bodies, linings or deflector plates.
The present invention can be utilized with high
effectiveness in ore concentration plants where ferrous and non-
ferrous ores are treated.
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