Abstrict A vertical shaft impact crusher is provided comprising a housing,
a rotor mounted within the housing for rotation about a vertical
axis and propelling incoming rock outwardly against a crusher ring,
wherein the crusher ring is comprised of segments each capable of
autogenous, impact or semi-autogenous crushing or combinations thereof
in order to precisely control the size and shape of crushed products.
Claims What is claimed is:
1. A vertical haft impact crusher comprising:
a housing having an outside surface, an inside surface and a cover
plate with an underside; a rotor mounted within said housing for
rotation about a central vertical axis and designed to receive axially
fed rock and propel it outwardly towards the inside surface of said
housing;
means for feeding said rock to the axial center of said rotor;
means for rotating said rotor about said axis;
an annular crusher ring releasably and adjustably mounted to said
inside surface of said housing on a substantially horizontal plane
with said rotor to receive and fragment said rock propelled by said
rotor, said crusher ring defining a circle and being comprised of
segments, each of said segments comprising means for selective formation
into crusher ring portions specifically intended for either autogeneous
crushing, impact crushing, semi-autogenous crushing, or combinations
thereof, said means including:
an anvil bracket provided on each of said segments, each of said
brackets having at least one leg having two ends, each of said at
least one leg being fastened at one end to and extending inwardly
from said ring on a secant to the circle defined by said ring, each
said second end being connected to a notched cross arm; and
an autogenous plate retaining bracket provided on each of said
segments, each of said plate retaining brackets having an annular
portion and a pair of spaced inwardly projecting radial portions,
each of said projecting portions being supported by a vertically
projecting gusset secured along a vertical edge thereof to said
ring.
2. The vertical shaft impact crusher described in claim 1 wherein
said underside of said cover plate is provided with a vertically-depending
annular ring positioned to facilitate the deposition of crushed
rock above said anvil brackets.
3. The vertical shaft impact crusher described in claim 1 wherein
said segments comprise autogenous and impact crushing portions arrayed
around said crushing ring.
4. The vertical shaft impact crusher described in claim 6 wherein
said autogenous and impact crushing portions alternate on a regular
basis.
5. The vertical shaft impact crusher described in claim 6 wherein
said autogenous crushing and impact crushing portions are of approximate
equal length.
6. A vertical shaft impact crusher for crushing rock or minerals,
comprising;
a housing having an outside surface, an inside surface and a cover
plate with an underside provided with a vertically depending annular
ring;
a rotor mounted within said housing for rotation about a central
vertical axis and designed to receive axially-fed rock and propel
it outwardly towards the inside surface of said housing;
means for rotating said rotor about said axis;
an annular crusher ring releasably and adjustably mounted to the
inside surface of said housing, said crusher ring defining a circle;
a plurality of impact breaker anvil brackets secured to and positioned
around said crusher ring, each of said brackets having at least
one leg having two ends, each of said at least one leg being fastened
at one end to and extending inwardly from said crusher ring on a
secant to the circle defined by said crusher ring, each said second
end being connected to a notched cross arm;
a plurality of impact breaker anvils removably positioned in a
select number of said cross arm notches to receive and fragment
rock thrown by said rotor;
a plurality of autogenous plate retaining brackets secured to and
regularly spaced about said crusher ring beneath said anvil brackets,
each of said plate retaining brackets including a pair of spaced,
inwardly projecting radial portions, each of said portions being
supported by a vertically projecting gusset having an inside and
an outside, and a pair of vertically projecting locating lugs, each
said gusset being secured along a vertical edge thereof to said
ring;
a plurality of substantially planar autogenous plates, each having
an inner peripheral edge with an upwardly projecting lip, and an
underside and being releasably secured to said crusher ring by said
plate retaining brackets between the insides of adjacent gussets
and in a selected radially inwardly projecting orientation to form
at least one rock-retaining ledge segment beneath said anvil brackets
which, when filled with rock, performs autogenous crushing;
wherein the selected sequence of autogenous plates and breaker
anvils around said ring creates autogenous crushing portions, impact
crushing portions and/or semi-autogenous crushing portions on said
crusher ring to allow the size and shape of said rock passing through
said crusher to be precisely regulated.
7. The vertical shaft impact crusher described in claim 6 wherein
said crusher ring is provided with equal proportions of breaker
anvils to form impact crushing portions, and autogenous plates to
form autogenous crushing portions in randomly alternating arrangement.
8. The vertical shaft impact crusher described in claim 6 wherein
said selected sequence includes said autogenous plates and said
breaker anvils alternating around said ring in regular arrangement.
9. The vertical shaft impact crusher described in claim 6 wherein
said autogenous portions are also provided with anvils in said impact
breaker anvil brackets to form semi-autogenous crushing portions.
10. The vertical shaft impact crusher described in claim 9 wherein
said annular cover plate ring may be provided in segments which
corresponds to said autogenous portions.
11. The vertical shaft impact crusher described in claim 10 wherein
said autogenous segments are provided with anvils in said impact
breaker anvil brackets to form semi-autogenous crushing portions.
12. The vertical shaft impact crusher described in claim 9 wherein
said crusher ring is secured to said inside surface of said housing
in a vertically adjustable manner.
13. The vertical impact crusher described in claim 9 wherein said
autogenous plates extend closer to said rotor than do said breaker
anvils.
14. A vertical shaft impact crusher comprising:
a housing having an outside surface, an inside surface and a cover
plate with an underside provided with a segmented vertically depending
annnular ring;
a rotor mounted within said housing for rotation about a central
vertical axis and designed to receive axially-fed rock and propel
it outwardly towards the inside surface of said housing;
means for rotating said rotor about said axis;
an annular crusher ring secured to the inside surface of said housing
in a vertically adjustable manner, said crusher ring defining a
circle;
a plurality of impact breaker anvil brackets positioned in a horizontal
plane upon said crusher ring, each of said brackets having at least
one leg, each leg with two ends, each leg being fastened at one
end to and extending inwardly from said crusher ring on a secant
to the circle defined by said crusher ring and each said second
end being connected to a notched cross arm;
a plurality of impact breaker anvils positioned in selected ones
of said cross arm notches to receive and fragment rock thrown by
said rotor;
a plurality of autogenous plate retaining brackets secured to and
regularly spaced about said crusher ring beneath said anvil brackets,
each of said plate retaining brackets including a pair of spaced,
inwardly projecting radial portions, each of said portions being
supported by a vertically projecting gusset having an inside, an
outside, and a pair of vertically projecting locating lugs, each
gusset being secured along a vertical edge thereof to said ring;
a plurality of autogenous plates, each having an upwardly projecting
lip on one edge and a pair of notched lateral edges, said notches
of said notched lateral edges engaging said locating lugs, said
plates extending horizontally inwardly towards said rotor to create
a rock retaining ledge for autogenous crushing when releasably placed
in said plate retaining brackets;
wherein the exact sequence of autogenous plates and breaker anvils
around said ring creates autogenous, semiautogenous, and/or impact
crushing portions on said crusher ring.
15. A crusher ring for a vertical shaft impact crusher, said ring
comprising a plurality of segments, and defining a circle, each
of said segments containing at least one anvil retaining bracket
having at least one leg, each leg with two ends and being attached
at one end to and extending inwardly from a segment on a secant
to the circle defined by said ring, each said second end being connected
to a notched cross arm, and an autogenous plate retaining bracket
having an annular portion and a pair of spaced, inwardly projecting
radial portions defining said segments, each of said radial portions
being supported by a vertically projecting gusset secured along
a vertical edge thereof to its corresponding segment.
16. The crusher ring described in claim 15 wherein said segments
are arranged so that every other segment is provided with an anvil
in said anvil retaining bracket, and the remaining segments are
each provided with an autogenous plate in said autogenous plate
retaining bracket.
17. The crusher ring described in claim 15 wherein approximately
a first half of the number of said segments is provided with anvils
in said anvil retaining brackets and a second remaining half of
the number of said segments is provided with autogenous plates in
said autogenous plate retaining brackets.
Description BACKGROUND OF THE INVENTION
The present invention relates to vertical shaft impact crushers,
and more particularly to a vertical shaft impact crusher capable
of autogenous, semi-autogenous, or impact crushing.
Impact crushers operate on the principal of accelerating the rock
to a high speed and causing it to impact against a target which
will cause the rock to fracture. There are essentially two types
of impact crushers: autogenous impact crushers and anvil impact
crushers. The autogenous variety uses a bed of the same material
that is being broken or crushed as the target area so that the rock
which is accelerated impacts against other rock of the same type.
Anvil type impact crushers utilize a hard block of material such
as manganese steel as the target area.
The autogenous and anvil types of impact crushers are used for
different purposes. Autogenous crushing is used primarily for reshaping
rock which is already approximately the right size. It is most frequently
used on wash gravel or natural rock which is smooth and needs to
be reshaped with flat faces so that it can be used as aggregate
in concrete and the like. Autogenous crushing also produces a large
number of fines, so that most of the product of autogenous breaking
or crushing is at the two extreme ends of the product size spectrum.
However, this crushing medium requires higher rotor tip velocities
to achieve desirable reduction ratios. Higher rotor speeds increase
horsepower requirements and substantially increase rotor wear.
Anvil breaking, on the other hand, produces a shattering action
on the rock so that the majority of the product is near the central
region of the product size distribution spectrum. Anvil breaking
is used primarily to reduce the size of the input rock rather than
to reshape rock which is already approximately the correct size.
The anvil crushing ring thus generates higher reduction ratios at
slower tip velocities, but does not generate a product shape of
comparable quality to the autogenous apparatus, commonly known as
the "rock box." The anvil ring reduces horsepower requirements
and minimizes rotor wear by allowing for slower rotor speeds.
Impact rock crushers are often mounted on trailers for transportation
from site to site, so that rock may be crushed at the location where
it is needed. However, in the past, it has been necessary to use
an autogenous crusher for autogenous crushing and to use an anvil
crusher for anvil crushing. One solution to this problem is disclosed
in commonly-assigned U.S. Pat. No. 4560113 where a vertical shaft
impact crusher is provided with a pair of interchangeable breaker
rings; one having anvils for impact crushing, and the other with
a rock box for autogenous crushing. Thus, in this case the operator
has a choice of performing either shaping or size reduction, but
not a combination of both.
Thus, there has been a need for a vertical shaft impact crusher
which is capable of adjusting or fine tuning the crushing process
to more accurately control the size and shape of the crushed product.
It is therefore an object of the present invention to provide a
vertical shaft impact crusher capable of autogenous, impact and/or
semi-autogenous crushing simultaneously to produce a product of
controlled shape and size.
It is a further object of the present invention to produce desired
product at a desired volume at lower rotor velocities in order to
reduce rotor tip wear and horsepower requirements.
SUMMARY OF THE INVENTION
The objects of the present invention are embodied in a vertical
shaft impact crusher provided with a crushing ring comprised of
alternating autogenous, impact and/or semi-autogenous crushing portions,
the specific sequencing and arrangement of which allows the operator
to precisely determine the size and shape of the crushed product.
More specifically, the present invention is comprised of a vertical
shaft impact crusher having a closed housing wherein a supply of
rock is fed through a hopper into the axis of a rotating impeller
or rotor. The rotor propels the rock outwardly against a crushing
ring located on the inside periphery of the housing. Where traditional
vertical impact crushers were provided with crushing rings designed
exclusively for impact, autogenous, or semi-autogenous crushing,
the present crusher is provided with a crushing ring which includes
segmented interchangeable and alternating crushing portions, each
portion designed for one of the three types of crushing mentioned
above.
The impact crushing portions are comprised of at least one anvil,
each of which is mounted to the crushing ring by means of a specialized
mounting bracket. The mounting brackets allow rotation of the anvil
head to equalize wear. The anvil brackets are located around the
entire periphery of the crusher ring to allow total flexibility
of anvil placement.
The autogenous crushing portions are comprised of a shelf-like
plate extending horizontally toward the rotor from the housing's
inner wall. These plates are located below the anvil brackets and
are designed to accumulate a bed of crushed rock which will become
the autogenous crushing surface.
The crushing ring is designed so that when desired, any of the
autogenous plates can be removed, and anvils placed in the brackets
to convert from autogenous to anvil crushing. Similarly, if semi-autogenous
crushing is desired, both anvils and autogenous plates may be placed
in the same ring segment.
DESCRIPTION OF THE DRAWINGS
The invention and its many attendant objects and advantages will
become more apparent upon reading the following description of the
preferred embodiment in conjunction with the following drawings,
wherein:
FIG. 1 is a sectional elevation of the vertical shaft impact crusher
made in accordance with this invention;
FIG. 2 is a partial sectional perspective of the vertical shaft
impact crusher shown in FIG. 1 with the cover and rotor removed
and a fragment of the crusher ring exploded out of the machine;
FIG. 3 is a plan view of the rotor and crusher ring of the present
invention wherein a combination of autogenous, impact and semi-autogenous
crushing may be performed;
FIG. 3A is an enlarged plan view of a portion of the crusher ring
of the present invention depicted in FIG. 3 with the anvil brackets
removed;
FIG. 4 is a section of one portion of the present crusher ring
in the semi-autogenous mode;
FIG. 5 is a section of a segment of the present crusher ring in
the autogenous mode; and
FIG. 6 is a section of a segment of the present crusher ring in
the semi-autogenous mode wherein a supplemental annular rock retention
ring is provided attached to the inner surface of the top lid.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, wherein like reference characters
designate identical or corresponding parts, and more particularly
to FIGS. 1 and 2 a vertical shaft impact crusher according to the
present invention includes a frame 10 on which is mounted a drive
motor 12 a crusher housing 14 bolted to the frame concentrically
around a pair of segmental openings 15 therethrough and a crane
16. A bearing cartridge 20 is also mounted directly to the frame
10 coaxially within the crusher housing 14. The bearing cartridge
20 supports for rotation about a vertical axis a shaft 22 which
has mounted on its top end a rotor 24 and mounted on its lower end,
a sheave 26 which is connected by way of a drive belt 28 to a corresponding
sheave 30 mounted on the lower end of the motor shaft 32.
A cover 34 is mounted on top of the crusher housing 14 and includes
a feed tunnel 36 mounted on a collar 38 which is welded to a cover
plate 40 concentrically with a central hole 42 and the cover plate
40. A series of radially extending tapered braces 44 are welded
to the collar 38 and to the cover plate 40 to strengthen the cover
and provide, by virtue of holes 46 in the braces 44 means for attaching
a hoist cable from the crane 16 when it is desired to lift the cover
off of the crusher housing 14.
The feed tunnel 36 has a floor plate 48 having a central opening
50. A feed tube 52 is welded to the underside of the floor plate
48 and depends therefrom to a level approximately equal to that
of the cover plate 40. A replaceable feed tube extension 54 is telescopically
disposed around the feed tube 52 and is provided with an extension
adjustment mechanism for adjusting the length of its extension through
the hole 42 in the cover plate 40.
A guard shell 63 made of a series of shell segments 64 is bolted
to the underside of the cover plate 40 concentrically around the
central hole 42. The shell segments are arcuate in form and include
an inwardly extending upper flange by which the segments 64 are
bolted to the cover plate. The liner segments 64 protect the top
of the rotor 24 from damage by broken rock bouncing off of a crusher
ring 70 mounted in the crusher housing 14 as as to be horizontally
aligned with the rotor 24.
The crusher ring 70 shown in FIG. 1 and shown in greater detail
in FIGS. 2-6 includes an annular hoop 72 of heavy steel construction
having an annular seal 73 fastened to its top surface for sealing
space between the hoop 72 and the crusher housing 14. Three or four
depending vertical legs 74 are welded to the underside of the hoop
72 at equally spaced annular positions around the hoop. The exact
number of legs will be determined by the load capacity of the ring
70. The legs 74 are supported by a like number of stepped mounting
blocks 76 welded to the inside of the crusher housing 14 as shown
most clearly in FIG. 2. The support blocks 76 have a plurality of
steps formed thereon at different angular positions and elevations
to provide a plurality of elevation settings for the crusher ring.
This enables the elevation of the crusher ring to be adjusted within
crusher housing 14 so that the vertical position of the crusher
ring relative to the rotor can be optimized for optimal crushing
efficiency and use of material, as explained more fully below.
The crusher ring 70 has welded thereon a series of brackets 78
each having two legs 77 fastened to and extending inwardly from
the hoop 72 on a secant to the circle defined by the hoop. A cross
arm 79 is welded to and extends between the outside end of each
pair of legs 77 and has a vertical slot 81 completely through the
arm 79. The cross arm 79 is actually made of two separate pieces,
one each welded to the end of each leg 77. Three lifting lugs 75
are welded to three legs 77 at equally spaced angular positions
around the crusher ring for attachment of a cable to hoist the crusher
ring in and out of the housing 14.
Each bracket 78 may support an anvil 80. Each anvil 80 includes
an octagonal head 82 having a flat octagonal face 83 a square foot
84 and square neck 86 connecting the head 82 and the foot 84. The
head, foot and neck of the anvil 80 are symmetrical about a horizontal
axis 88 forming an angle with a tangent 87 of the rotor through
the anvil of about 5.degree.-15.degree., with 10.degree. being preferred
as shown in FIG. 3. This angle represents the radial component of
velocity exerted by the rotor on the rock as it is propelled from
the rotor. The radial component of velocity is a function of the
rotor pocket face angle, as discussed below.
Each anvil 80 is supported on a bracket 78 by lowering the anvil
neck 86 into the slot 81 in the cross arm 79 until the anvil foot
84 contacts a support plate 89 welded to the bottom of the bracket
legs 77 and cross arm 79. The support plates 89 support the vertical
weight of the anvil 80 and also rigidify the brackets 78.
The brackets 78 are welded from simple flame cut pieces for great
economy and precision of manufacture, and also great strength. The
pieces all overlap each other slightly to provide a convenient and
economical outside rabbets in which the pieces can be quickly and
securely welded. The structure is so open and accessible that it
is particularly suitable for automatic welding operations.
The octagonal faces 83 of the anvil heads 82 represent an efficient
utilization of anvil material, since the corners of a square or
rectangular anvil are not impacted by rock in a centrifugal impact
crusher of the present design. The octagonal face is symmetrical
about the axis 88 of the anvil so that the anvil may be rotated
by multiples of 90.degree. without changing the pattern of anvil
faces presented to the rotor 24. It is thus possible to maintain
a substantially uniform and consistent anvil array throughout the
useful life of the anvil. The support blocks 76 spaced at equal
angular positions around the crusher housing 14 enable the crusher
ring 70 to be rotated to as many positions as there are support
blocks 76 four being disclosed herein. In practice, the rocks tend
to be thrown predominantly in one angular region where they tend
to fall into the rotor predominantly toward one side because of
the conveyor feeder. Consequently, the anvils 80 in that one angular
region tend to wear faster than in other regions. By periodically
rotating the breaker ring incrementally, it is thus possible to
distribute the anvil wear more evenly.
The rotor, as seen in FIGS. 1 and 3 includes a circular base plate
90 having an axial hub 92 formed integrally on the vertical center
line 94 of the rotor. A top plate 96 is disposed vertically above
and parallel to the base plate 90 and coaxial therewith. The top
plate 96 is held in spaced relationship to the base plate 90 by
a series of vertically oriented partitions or plates which form
four autogenous pockets 98 spaced equally around the rotor. Each
pocket 98 is formed of an arcuate circumferential or peripheral
plate 100 and a radial plate 102 welded to the trailing end of the
circumferential plate 100 in the sense of the direction of rotation
thereof. A pocket floor plate 104 is welded at an angle of about
76.degree. between the radial plate 102 and the arcuate plate 100.
The angle is selected to lie approximately parallel to the top face
106 of the dirt and rock bed which collects and is held in pocket
98 while the machine is in operation, although the angle of face
106 may be adjustable by the technique disclosed below. The pocket
floor plate 104 reduces the mass of the rock in the pocket to minimize
the severity of the imbalance if one rock bed becomes dislodged.
The leading edge of each arcuate plate 100 on the end remote from
the end to which the radial plate 102 is connected, has attached
thereto a wear resistant bar 110. The wear resistant bar 110 is
attached to the leading edge of the arcuate plate 100 by two bolts
112 which pass through a back-up bar 114 on the outside of the arcuate
plate 100 to protect the bolts 112 from erosion by broken rock ricocheting
off the anvils 80. The leading inside edge of the wear resistant
bar 110 includes a slot in which is fixed, as by silver soldering,
a piece of hard, wear resistant material 116 such as silicon carbide.
The radial inside edge of the radial plate 102 is protected from
erosion by a wear bar 118. The wear bar 118 is an L-shaped member
which is held in place on the radial plate 102 by tack welding and
is removed by burning through the tack weld with a torch. The wear
bar 118 is made of a high chrome steel and does not require the
silicon carbide insert as used in the wear bar 110 because the wear
bar 118 is much closer to the axis of the rotor than the wear bar
110 so it is not subjected to the same degree of erosive action
that the wear bar 110 experiences as rocks are accelerated off its
feeding edge.
The angle selected for the face 106 of the rock bed in the pocket
98 is controlled by the length of the radial plate 102 and the effective
length of the peripheral arcuate plate 100. The effective length
of both plates can be varied by the use of different wear bars 110
and 118 having greater length so they effectively extend past either
the radial plate 102 (for a smaller angle of the face of the rock
bed) or the arcuate plate 100 (for a greater angle of the rock bed
face).
To increase the shattering effect of the rotor itself on the rock,
it may be desirable to replace the autogenous rotor pocket structure
with conventional cast iron impeller shoes. The rotor 24 of this
invention will accommodate the installation of conventional shoes
mounted directly to the walls 100 102 and 104 or could be mounted
directly to the rotor base plate 90 in place of the autogenous pocket
walls.
A pair of wear plates 120 and 122 is fixed to the rotor base plate
90 and the rotor top plate 96 respectively, in each of the four
quadrants of the rotor. The bottom wear plate 120 is fixed to the
top surface of the rotor base plate 90 by a pair of bolts 124 which
pass through the wear plate 120 and the rotor base plate 90 and
are locked into position by suitable locking nuts.
A protective skirt or lower outer guard ring 142 is tack welded
around the outside periphery of the rotor base plate 90 projecting
vertically slightly above the top surface thereof and vertically
below the top surface thereof a distance approximately equal to
the thickness of the rotor base plate 90. The skirt 142 protects
the edge of the rotor base plate 90 from erosion and also provides
a shoulder by which the position of the bottom wear plate 120 can
be located for ease of insertion of the mounting bolts when the
wear plate 120 is replaced.
A top guard ring or rim 144 is welded to the rotor top plate 96
in the same manner used to weld the protective skirt 142 to the
rotor base plate 90. The top of the top rim 144 projects above the
top surface of the top plate 96 and forms a shoulder 145 therewith.
The skirt 142 and the top rim 144 provide a prestressed support
ring to radially support the wear plates 120 and 122. Under high
centrifugal force, the skirt and rim, if not prestressed, could
expand slightly and lessen the radial support provided to the wear
plates.
The rotor hub 92 is held to the top of the shaft 22 by a conventional
key arrangement.
The shaft 22 is supported by a cylindrical bearing cartridge 20
shown best in FIG. 2. A heavy cylindrical cartridge housing 154
is attached to a bridge 155 in the base of frame 10 between the
two segmental openings 15 by bolting a lower flange 156 integral
with the housing 154 and into which is drilled a plurality of holes
to receive bolts 160 by which the bearing cartridge housing 154
is fastened to the frame bridge 155.
A cylindrical dust shell 194 surrounds the bearing cartridge 20
and is supported thereon by a radially inwardly extending flange
196 which is bolted to a radially outwardly extending flange 198
adjacent the top of the cartridge housing 154. A rubber bumper 200
is fitted on the lower end of the dust shell 194 and is slightly
compressed between the dust shell and the frame 10 to exclude dust
from the bearing cartridge and to dampen vibration and minimize
noise. A urethane shield 202 is secured to the outside surface of
the dust shell 194 to prevent abrasive damage to the dust shell
and also to dampen vibration and minimize noise. The urethane shield
202 may be bolted to the dust shell or may be bonded directly to
the shell.
Referring now to FIGS. 1 and 2 the crusher housing 14 is a cylindrical
tank having a rubber bumper 222 placed on the top lip of the tank
to act as a dust seal and also to dampen vibration and to attenuate
noise. An annular bracket 224 is welded around the outside surface
of the tank slightly below the top lip and provides a support to
which the bottom edge of a plurality of upright locking tongues
226 are welded. Each locking tongue has a rectangular hole 228 punched
in its upper end for receiving a lock wedge 230. The cover plate
40 has a series of short radial slots 232 at its outside edge at
angular positions corresponding to the angular positions of the
locking tongues 226 around the housing 14 so that when the cover
is placed on the top of the housing 14 with the locking tongues
lined up with the slots 232 the tongues 226 will extend through
the slots 232 and the lock wedges 230 may be driven into the holes
228 to lock the cover in place.
A series of spacer blocks 234 is welded on a horizontal line around
the inside of the tank just beneath the stepped support block 76.
The spacer blocks 234 are each drilled and tapped to accept a bolt
236 which fastens a rubber curtain 238 at its top edge to the spacer
blocks. The rubber curtain 238 hangs down to the floor around the
full inside circumference of the crusher housing 14. It prevents
abrasion of the tank wall and is extremely effective in dampening
vibration and noise during operation.
The crusher ring 70 can be removed by attaching a cable hook to
each of the three lifting lugs 75 attached to the three bracket
legs 77 at equally spaced positions around the annular hoop 72 of
the crusher ring 70 and lifting the crusher ring out of the crusher
housing 14.
The preceding discussion has described a vertical shaft impact
crusher capable of anvil crushing exclusively. Purely autogenous
crushers are also well known in the prior art. However, many applications
call for a crushed product which is best obtained through a combination
of anvil and autogenous crushing. Until the present invention, such
a combination was unavailable on a single crushing ring 70.
In the present invention, and referring to FIGS. 2 3 3A and 5
autogenous crushing is obtained through the use of at least one
removable flat plate 280 which extends on a substantially horizontal
plane from the crusher ring 70 towards the rotor 24. Each plate
280 may be provided around its inner periphery with a vertically
projecting flange 282 to facilitate the retention of a sufficient
quantity of rock to form an autogenous bed 284. The plates 280 are
releasably secured to the crusher ring 70 by being placed upon a
pair of supporting gusset members 286 and an annular bracket 283.
The gussets 286 are constructed and arranged to support two adjacent
plates 280. Bracket 283 is provided with radially projecting portions
285 and is secured to the lower edge of the crusher ring 70 to support
plate 280. Each gusset 286 is provided with a pair of vertically
projecting locating lugs 287 located at the protruding end of gusset
286. Lugs 287 are positioned to engage notches 288 on each lateral
edge of plates 280 to locate and position the plates upon crusher
ring 70. Plate 280 is thus secured without the use of supplemental
fasteners or tools. Once the crusher is in operation, the plates
280 will be secured upon ring 70 by the accumulation of crushed
rock which forms the autogenous bed 284.
In some cases, semi-autogenous crushing may also be desired. As
is shown in FIG. 4 the autogenous retention plate 280 is placed
in a portion of the crusher ring 70 and is accompanied by an anvil
which has been placed in the bracket 78.
Specifically referring to FIG. 3 it can be seen that the radially
projecting portions 285 of annular bracket 283 roughly divide the
crusher ring 70 into a plurality of segments 289 the number of
segments approximating the number of radially projecting portions
285. Each segment 289 may be provided with an anvil 80 a plate
280 both plate and anvil, or neither feature. In addition, groups
of adjacent segments may be similarly outfitted to achieve the same
crushing characteristics. Furthermore, the crusher ring 70 may be
outfitted so that the crushing characteristics of one segment 289
overlap the adjacent segment. For example, in a segment fitted with
two anvil brackets 78 an anvil may be placed in only one bracket,
and a plate 280 may be included to create a segment with semi-autogenous
and autogenous characteristics.
Referring now to FIG. 6 in order to further cover the anvil with
a layer of autogenous rock on its upper surface, the interior of
cover plate 40 is provided with an annular, vertically depending
ring 290 which, when cover 40 is in place, creates an additional
retention area for crushed rock. This annular ring 290 may be provided
in segmental form to further adjust the shaping and sizing of the
particular products of the crusher. The use of a ring segment 290
is not restricted to those portions containing anvils, but may also
be placed over crusher ring portions designed for autogenous and/or
semi-autogenous crushing.
The crane 16 includes a support pillar 254 to which a pair of brackets
256 are attached for supporting a crane control box by which the
crane 16 is controlled. A bearing (not shown) around the upper portion
of the support pillar 254 rotatably supports the upper end of the
crane 16 which includes a vertical extension 260 and a cantilevered
horizontal arm 262. A support bracket 264 is welded to the lower
end of the vertical extension 260 and supports an electric motor
266 coupled to a gear pump 268.
A hydraulic rotation motor (not shown) is coupled between the upper
portion of the crane 16 and the support pillar to allow the upper
portion of the crane to be rotated about the support pillar. A motorized
hydraulic winch 272 allows a hook 274 to be raised or lowered by
taking up or playing out cable from a winch drum (not shown).
In operation, rock to be crushed is continuously fed into the feed
tunnel 36 and falls through the feed tube 52 and the feed tube extension
54 and into the center of the rotor 24. The rotor rotates at variable
speeds on the order of about 900-1800 RPM. The rock is thrown radially
outward where it is caught and accelerated by the rotor pockets
98. The rotor pockets soon become covered with a blanket of rock
which protects them from erosion by the rock as it is thrown outward.
The only surfaces which encounter erosion within the pocket are
the wear plates 120 and 122 and the inner and outer wear bars 118
and 110. These wear pieces are all easily and quickly replaceable
when they wear down.
The rock is thrown by the pockets 98 outwardly against either the
anvil breaker 80 the autogenous bed 284 or the semi-autogenous
portion 292. The trajectory of the rock is about 5.degree.-15.degree.
out from the tangent to the rotor. The deviation from tangential
trajectory is caused by the angle of the rock face within the pocket
98 and the coefficient of friction of the rock-on-rock as the rocks
are thrown radially outward. The brackets 78 are set in the crusher
ring 70 at an angle such that the faces of the anvils 80 lie perpendicular
to the flight trajectory of the rock which is about 10.degree. out
of tangent to the rotor. In this way, the rocks will strike the
anvil faces exactly perpendicular so that the full momentum of the
rock is converted to an internal shattering force and little of
the energy is wasted on ricochet force. The broken rock then falls
vertically downward between the rubber curtain 238 and the dust
shell 194 and through the openings 15 on the two sides of the cartridge
support bridge 155. The rock is then carried away by suitable conveyor
means (not shown).
Faced with very specific product needs, the crusher operator will
determine the desired combination of anvil, autogenous bed, or semi-autogenous
crushing characteristics to create the most desirable product. The
crusher ring segments 290 are then assembled so as to have the desired
combination of characteristics by removing or combining anvils 80
with plates 280 and/or lid segments 290 as is shown in FIG. 3.
If desired, a totally autogenous, totally semi-autogenous or totally
impact breaker type crusher ring may also be provided.
Obviously, numerous modifications and variations of the above-described
preferred embodiment will occur to those skilled in the art in light
of this disclosure. Accordingly, it is expressly to be understood
that these modifications and variations, and the equivalents thereof,
may be practiced while remaining within the spirit and scope of
this invention as defined in the following claims. |