U.S. patent number 3,682,397 [Application Number 04/802,907] was granted by the patent office on 1972-08-08 for apparatus for crushing and separating ore material.
Invention is credited to Albert G. Bodine.
United States Patent |
3,682,397 |
Bodine |
August 8, 1972 |
APPARATUS FOR CRUSHING AND SEPARATING ORE MATERIAL
Abstract
Earth is crushed and ore can be separated therefrom by passing
the earthen material over a sonically activated surface. The earth
is kept acoustically coupled to the surface through the use of a
low impedance medium which can be rubber, liquid mercury, and the
like.
Inventors: |
Bodine; Albert G. (Van Nuys,
CA) |
Family
ID: |
25185050 |
Appl.
No.: |
04/802,907 |
Filed: |
February 27, 1969 |
Current U.S.
Class: |
241/46.01; 241/1;
241/283; 241/264 |
Current CPC
Class: |
B02C
19/16 (20130101) |
Current International
Class: |
B02C
19/00 (20060101); B02C 19/16 (20060101); B02c
019/16 () |
Field of
Search: |
;241/DIG.30,86,102,264,201,202,146,46R,46.02,46.04,46.13,265,290,283,262 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kelly; Donald G.
Claims
I claim:
1. A device for crushing earth particles comprising:
a flat plate,
means connected to said plate for acoustically vibrating said
plate,
means for directing said earth particles to said plate,
and low acoustic impedance means comprising a liquid mercury bath
disposed adjacent said plate for maintaining said earth in contact
with said plate.
2. The device of claim 1 wherein said vibrating plate is disposed
below the surface of said mercury bath.
3. The device of claim 1 and further including a housing wherein
said mercury is disposed, said plate being adjustably disposed in
spaced relationship to the bottom of the housing, said means for
directing the earth to said device serving to direct the earth
between said housing bottom and said plate.
Description
Prior to the herein invention, sonic energy has been used for the
crushing of rock and earthen material. If one wishes to crush earth
in a continuous operation where the earth particles or clod
particles flow in a chute or the like, there is a problem relating
to keeping the material to be crushed or treated acoustically
coupled to the radiating surface. The tendency is for the earthen
material to bounce away from the surface and not stay acoustically
coupled. As a result, one does not obtain effective or efficient
crushing or treatment of the earth. The herein invention is
particularly concerned with the crushing of earth material where
ore is apt to be located. If a rigid wall is used to trap the
earthen material against acoustic radiant surface such as a solid
piece of steel, there is a tendency to crush or treat everything
between this rigid wall and the radiating surface. The tool then in
effect becomes a sonic rock crusher. In such an instance, hard
rocks and other undesirable material are equally treated
acoustically along with the softer earth material.
Thus an object of this invention is to provide a device having a
proper selection of impedance so as to selectively match up with
the impedance of a desired material in a medium and also utilized
to keep earth in contact with a sonically vibrating surface, such
that rocks and other undesirable materials are not treated, and in
effect remain in their original size so that they can easily be
rejected at a subsequent stage of the process.
Another object of this invention is to provide a medium for keeping
earth acoustically coupled to a sonically radiating surface.
The above and other objects of this invention are accomplished by
an apparatus whereby a surface of an elastic material, for example
metal plate, is provided. Coupled or fixed to the plate is a means
for sonically vibrating it, such as an orbiting mass oscillator.
Means is provided for feeding the earth material to be crushed to
the vibrating surface. A low impedance medium, such as a layer of
rubber, serves to keep the earth material to be crushed in contact
with the vibratory plate. The rubber in one embodiment can be in
the form of rotating wheels or in another embodiment can be a
single flat sheet or the like. In another embodiment of the
invention the low impedance medium utilized to deep the earth in
contact with the vibratory surface is liquid metal, such as liquid
mercury. The advantage of utilizing mercury as a medium is that it
can serve to separate the various particles as a function of their
density, which will be further explained. The invention will be
further understood from the following detailed descriptions and
drawings, in which:
FIG. 1 represents a schematic side representation of a first
embodiment of this invention;
FIG. 2 is a large cross sectional view of a portion of the device
of FIG. 1 showing the details of the rock crushing mechanism;
FIG. 3 is a sectional view taken along lines 3--3 of FIG. 2;
FIG. 4 is a sectional view taken along lines 4--4 of FIG. 2;
FIG. 5 is a cross sectional side view of a second embodiment of the
invention;
FIG. 6 is a sectional view taken along lines 6--6 of FIG. 5;
FIG. 7 is a cross sectional side view of a third embodiment of the
invention;
FIG. 8 is a sectional view taken along lines 8--8 of FIG. 7;
FIG. 9 is a cross sectional front view of a fourth embodiment of
this invention utilizing liquid mercury;
FIG. 10 is a top plan view of FIG. 9;
FIG. 11 is a cross sectional view taken along lines 11--11 of FIG.
9;
FIG. 12 is a cross sectional view taken along lines 12--12 of FIG.
9;
FIG. 13 is a cross sectional view of a fifth embodiment of the
invention utilizing liquid mercury; and
FIG. 14 is a sectional view taken along lines 14--14 of FIG.
13.
It has been found most helpful in analyzing this invention to
analogize the acoustically vibrating circuit utilized to an
equivalent electrical circuit. This sort of approach to analysis is
well known to those skilled in the art and is described, for
example, in Chapter 2 of "Sonics" by Hueter and Bolt, published in
1955 by John Wiley and Sons. In making such an analogy, force F is
equated with electrical voltage E, velocity of vibration u is
equated with electrical current i, mechanical compliance C.sub.m is
equated with electrical capacitance C.sub.e, mass M is equated with
electrical inductance L, mechanical resistance (friction) R.sub.m
is equated with electrical resistance R and mechanical impedance
Z.sub.m is equated with electrical impedance Z.sub.e.
Thus, it can be shown that is a member is elastically vibrated by
means of an acoustical sinusoidal force F.sub.o sin.omega.t/u
(.omega. being equal to 2.pi. times the frequency of vibration),
that
Where .omega.M is equal to 1/.omega.C.sub.m, a resonant condition
exists, and the effective mechanical impedance Z.sub.m is equal to
the mechanical resistance R.sub.m, the reactive impedance
components .omega.M and 1/.omega.C.sub.m cancelling each other out.
Under such a resonant condition, velocity of vibration u is at a
maximum, power factor is unity, and energy is more efficiently
delivered to a load to which the resonant system may be
coupled.
It is important to note the significance of the attainment of high
acoustical Q in the resonant system being driven, to increase the
efficiency of the vibration thereof and to provide a maximum amount
of power for crushing the earth particles and separating ore. As
for an equivalent electrical circuit, the Q of an acoustically
vibrating circuit is defined as the sharpness of resonance thereof
and is indicative of the ratio of the energy stored in each
vibration cycle to the energy used in each such cycle. Q is
mathematically equated to the ratio between .omega.M and R.sub.m.
Thus, the effective Q of the vibrating circuit can be maximized to
make for highly efficient, high-amplitude vibration by minimizing
the effect of friction in the circuit and/or maximizing the effect
of mass in such circuit.
In considering the significance of the parameters described in
connection with equation (1), it should be kept in mind that the
total effective resistance, mass, and compliance in the
acoustically vibrating circuit are represented in the equation and
that these parameters may be distributed throughout the system
rather than being lumped in any one component or portion
thereof.
It is also to be noted that orbiting mass oscillators are utilized
in the implementation of the invention that automatically adjust
their output frequency and phase to maintain resonance with changes
in the characteristics of the load. Thus, in the face of changes in
the effective mass and compliance presented by the load with
changes in the conditions of the work material as it is sonically
excited, the system automatically is maintained in optimum resonant
operation by virtue of the "lock-in" characteristic of applicant's
unique orbiting mass oscillators. Furthermore, in this connection
the orbiting mass oscillator automatically changes not only its
frequency but its phase angle and therefore its power factor with
changes in the resistive impedance load, to assure optimum
efficiency of operation at all times. The vibrational output from
such orbiting mass oscillators also tends to be constrained by the
resonator to be generated along a controlled predetermined coherent
path to provide maximum output along a desired axis.
Turning now to FIGS. 1 to 4, there is seen a first embodiment of
the invention. The first embodiment utilizes a rubber blanket in a
manner that will be described. The device 11 can be pivotally
mounted on a support structure 13. An I beam structure 15 serves as
the basic support for the operative portion of the device. One end
of the structure 15 is connected to a pneumatic piston 19 which
serves to rotate it about point 17 from a horizontal position as
for example shown in FIG. 2 to a slightly downward position shown
in FIG. 1.
Two I beams 21 are affixed to cross pieces 23 of the support
structure 15. The I beams support a flat metal plate 25 through
rubber mounts 27. The rubber mounts 27 are rigidly affixed to the I
beams 21, while not being affixed to the plate 25. As seen, plate
25 is the plate upon which the earth 31 moves as it traverses along
the device. Connected to the forward end of plate 25 is an orbiting
mass oscillator 33, which serves to sonically vibrate the plate in
accord with this invention. The oscillator 33 is driven by motor 35
acting upon gears 37 and a gear box unit 39 so as to drive the
shaft 41 to cause rotation of the oscillator. The oscillator used
can be that shown for example in U. S. Pat. No. 3,402,612. Adjacent
the forward end of the vibratory plate 25 is an upright wall
portion 43, having an opening 47 therein. The earthen particles 31
are directed by a chute 49 affixed to opening 47 onto the plate
25.
Side walls 45 parallel the vibratory plate and serve to confine the
earthen particles. Walls 45 are spaced a very slight distance 51
from the plate so as to allow free vibratory motion of the plate
without interference from the walls.
Since the bottom of vibratory plate 25 is essentially freely
suspended, undue dislocation can effect the drive shaft 41 to the
oscillator. To prohibit such movement, a shackle 53 is affixed to
the forward end of the plate 25 which passes through an aperture 55
in wall 43. The shackle is connected to a cable 57 which is
enclosed in a damping pipe 59. The cable 57 in turn is connected to
a second shackle 61 affixed to a support beam 63. Where the plate
25 is vibrated the vibrations are carried through the cable 57
which would snap if not damped by the enclosed pipe piece 59. Thus
it can be appreciated the arrangement of the shackle and cable 57
prevent undue horizontal displacement of the vibratory plate, as
well as preventing the plate from slipping out of the device when
it is tilted in a position such as shown in FIG. 1.
Freely suspended by a cable 65 from the back wall 43 is a blanket
67 of an elastic material such as rubber or the like. The blanket
67 serves as the aforementioned low impedance drive or reflective
medium which keeps the desired earth particles in contact with the
vibratory surface 25 in the operation of this device. The rubber
blanket 67 is a good acoustic match for earthen clods and softer
earthen materials wherein very often finely divided ore dust such
as gold particles exist. The rubber medium contains the softer
earth material and acoustically couples it to the sonic radiant
surface 25, whereas rocks and other hard particles freely bounce
around in the space between the rubber blanket 67 and the surface
25. The rocks are then dropped off at the end 69 of the surface
together with the finely divided material leaving the device.
The orbiting mass oscillator 33 utilized forms a main sonic circuit
together with the radiating surface or plate 25. The sonic circuit
has a very discreet acoustic impedance so that the resonant
phenomena is well defined and quite stable. The earthen material 31
being treated appears in the sonic circuit only as a resistive
impedance, not having too much effect upon the resonant frequency
phenomena. However, the earth does occasionally have some effect
upon resonant frequency when there is mass loading due to high
density regions of the ore being applied to the resonating circuit.
As a result, it is desirable to use a vibratory type of orbiting
mass sonic oscillator, since it tends to adjust its frequency
automatically as the circuit impedance factors change. Further, the
orbiting mass oscillator adjusts its phase angle and its power
factor to accommodate changes in resistive impedance as different
quantities of ore come into contact with the sonic radiating
surface 25. One particular advantage of using the orbiting mass
oscillator is that it has a capability of a very high power output
without requiring complicated electronic gear, which is difficult
to maintain and uneconomic in field processes such as the treatment
of ore or other materials. A simple diesel engine or electric motor
35 can drive the oscillator as shown.
As can be seen, the sonic circuit is designed so that the radiating
surface is used in combination with a fairly high mass reactive or
inductive impedance such as a large chunk of steel. In the
embodiment of FIGS. 1 to 4 this takes the form of the large metal
plate 25. The advantage of the heavy mass forming the high
impedance in the circuit is the mass that maintains the circuit at
a fairly high acoustic Q even though there will be a fairly high
resistive impedance at the point where the surface of this mass is
applying energy into the ore that is being treated.
Without the presence of the low impedance media, satisfactory
results in crushing the earth particles and separating the ore are
not easily achieved. The earth material, since it is granular in
nature, will act as an entire body when subjected to the vibratory
energy and stand away some short distance from the vibrating
surface. This, of course, minimizes the amount of energy that is
received. The low impedance rubber blanket 67 prevents this from
occurring.
Turning now to the embodiment schematically shown in FIGS. 5 and 6,
it is seen that the same arrangement essentially shown in the
embodiment of FIGS. 1-4 is utilized. The device 71 shown therein
comprises a flat vibratory plate 73 driven by a pair of orbiting
mass oscillators 75 operating in unison in a manner similar to that
disclosed in U. S. Pat. No. 3,417,966. Plate 73 is supported on I
beams 77 and rubber isolators 79 in the same manner as disclosed in
the previous embodiment. The main difference between this device
and that previously described is that the herein embodiment uses a
large fixedly secured rubber mat 81 which is adjustable by jack
screws 83. The jack screws 83 in turn can be connected to a support
frame 85 for the device. As shown, the rubber mat can be affixed to
an upper plate 87 which in turn is affixed to side plates 89 that
serve to enclose the earthen material 91 between the rubber mat 81
and the vibratory plate 73. Thus the mat can be adjusted to
accommodate various size earthen particles and control the size of
the final crushed material.
Another embodiment utilizing rubber as a low impedance can be seen
in FIGS. 7 and 8 wherein the rubber takes the form of a cylindrical
body 91. Shown for example, are three large rubber or pneumatic
wheels 93 which can be driven by a motor 95 and pulley arrangement
97 and 99. The wheels can be angularly disposed as shown in FIG. 7,
so that the wheel closest to the inlet chute 101 is furthest away
from vibrating plate 103. This provides for a stepwise breakdown of
earth particles to the final desired size. The wheels are rotated
in a clockwise direction which serves in a manner similar to a
rubber conveyor and force the ore into the area between the rollers
and the vibrating surface 103. Additionally, the rollers serve to
maintain the contact area in a fairly thin layer in a similar
manner as seen in the embodiment of FIG. 5.
Turning now to FIGS. 9-12, there is seen an embodiment of the
invention utilizing a liquid mercury as a low impedance medium for
keeping earth particles in contact with a vibratory sonic radiating
surface. The device 105 comprises an enclosed housing 107 which can
be supported by a stand 109. A U-shaped support frame 111 is
disposed within the housing 107 and secured by bolts 113. Suspended
from the frame 111 is an elongated flat metal plate 115 which
comprises the vibratory element of the system. The bar is secured
to the support frame 111 by jack screws 117 so as to be adjustable.
The jack screws 117 are located toward the one end of the plate 115
as particularly seen in FIG. 9 such that an adjustment of the jack
screws can move the rear end 119 of the plate downward and tilt the
front end 121 upwardly for reasons to be subsequently
explained.
Affixed to a mid portion of the vibratory plate 115 is an orbiting
mass oscillator 123. The orbiting mass oscillator can be of the
type seen in the embodiments of FIGS. 1 to 4. Lines 125 carry air
pressure to drive the oscillator from a source outside of the
device and not shown. Adjacent the rear end 119 of the vibratory
plate 121 is provided an inlet 127 intersecting the bottom 129 of
the housing 107 for admitting earthen particles to the device.
Intersecting the inlet line 127 is a screw feed mechanism 131 to
force feed the earth particles 133 to the device. This is necessary
to overcome the effect of the mercury present. As can be seen, of
course, the mercury 135 will seek a level in the screw feed
equivalent to its level in the device. The level of the mercury in
the device is kept to a point just below an exit port 137 to which
is affixed an outlet shute 139 to carry the crushed particles of
earth 133 out of the apparatus.
As can be seen, the vibratory plate 115 is in intimate contact with
the layer of mercury immediately under it. It is particularly
apparent in cross sectional views of FIG. 11 or 12. The plate 115
is actually formed with a channel 141 along its bottom surface. The
channel is formed by two lateral sides 143 and a downward
protrusion 145 at the rear end thereof, thus serving to enclose the
entering particles within the confines of the channel 141 as they
move through the device preventing them from passing around the
sides of the plate to the top of the mercury level, which is
considerably above the bottom surface of the plate.
Thus it can be appreciated that the embodiment shown in FIGS. 9-12
provides a radiating surface wherein a contact area exists against
which the mercury is pressing so as to form an extended surface.
Thus as the earth material is introduced into this contact region
it is automatically spread out in a thin layer. Because the mercury
is of greater density, the earthen material cannot sink down. The
earth then literally floats on the surface of the mercury and
against the radiating surface which in effect is the ceiling above
the mercury body. The earth particles will flow from the inlet line
127 to the exit port 137 by gravity flow. This is accomplished by
slightly tilting the surface 115 downwardly at its rear end 119,
utilizing the jack screws provided. Thus in effect the surface of
the mercury underneath the platen 115 tilts upwardly toward the
exit and the force of the mercury against the earth particles will
direct them from the inlet to the outlet. The successive earth
particles 133 are built up on top of the mercury 135 adjacent the
exit port 137. They will tend to leave the device and fall out
through the chute 139.
Turning now to FIGS. 13 and 14, there is seen another embodiment of
an apparatus utilizing the principle of the invention together with
liquid mercury. Device 151 comprises the large tank 153 containing
liquid mercury bath 155. The tank is provided with an outlet port
157 which is connected to a recirculating line 159. Thus the
mercury is pumped through the device and recirculated by pump 161
back to an inlet line 163. This provides for a constant current of
mercury as shown by the arrows through the bath in a direction from
the inlet to the outlet. Located on the inlet side of the device is
a screw feed auger 165 which directs the earth particles 167 from a
hopper 169 into the mercury bath. Disposed in the bath below the
surface thereof is a housing 171 supported by structure 173
connected to a neck portion 175. The housing may be rectangularly
or circularly shaped as shown with the upperwardly extending
enclosed neck portion 175. Disposed within the housing is a massive
sonic radiating plate 177. A pair of orbiting mass oscillators 179
acting in unison as shown in U. S. Pat. No. 3,123,043 are coupled
through bar 181 to the radiating surface 177 and serve to create
resonant vibration on bar 181 and plate 177. Acoustic isolators 183
of elastomeric material are located preferably in the upper corners
of the housing 171, as seen in both Figures. The bar 181 freely
slides within the neck portion 175 of the housing and thus allows
the radiating surface 177 to move independent of the housing. A
guide channel 185 for the earth particles is provided in housing
171, by the side walls thereof, with flow starting at a cut away
portion of the side walls of the housing adjacent the end of the
feed auger thereof as seen in FIG. 14. The opposite side of the
housing is also cut away at 187 to complete the aforementioned
channel 185 at the exit end of the vibrating plate 177. As the
particles leave the plate 177 through the aperture provided in 187,
they are selectively separated. They ultimately pass out through a
plurality of exit holes 189 in the side walls of the device.
Baffles 191 between the exit holes 189 further serve as separation
means. As can be appreciated, the lightest particles will rise
first to the surface of the mercury and pass through the exit hole
189 closest to the vibrating surface 177 while the heaviest
particles will rise more slowly and be carried by the current to
the exit hole furthest from the vibrating plate. By providing a
varying number of exit holes 189 selected particle classifications
can be obtained from successive openings.
* * * * *