Abstrict An improved housing embedded in the ground for use in crushing
of ore. The housing has a generally figure eight configuration in
plan defined by a pair of hollow, upright cylindrical segments with
a common wall between the points of intersection of the segments.
One segment houses a dump pocket, an ore crusher, a surge chamber
and a discharge feeder and conveyor in descending order, and the
other segment contains drive machinery, dust control apparatus,
a lubrication system, hoist ways, elevator shaft, and other service
facilities. The crusher in the first segment is supported on a floor
supported by the wall of the first segment itself. The housing requires
only a minimum of concrete and reinforcing steel since the cylindrical
configuration of the sections thereof provide the most efficient
resistance to lateral pressures resulting from earth backfill and
surcharge from heavy haul trucks.
Claims We claim:
1. Structure for containing an ore crusher and associated ore handling
equipment below ground level comprising: a hollow, concrete housing
having a pair of upright tubular segments and a common wall between
the segments at the region of intersection thereof, the segments
having convex outer surfaces and defining with the wall a generally
figure eight configuration, the housing adapted to be disposed below
ground level and having a floor disposed within and integral with
one of the segments for supporting an ore crusher, said floor having
an opening therethrough, the ore crusher being operable to discharge
through said opening when the ore crusher is supported by said floor.
2. Structure as set forth in claim 1 wherein each segment is transversely
circular throughout a major portion thereof.
3. Structure as set forth in claim 1 wherein at least one of the
segments is transversely elliptical throughout a major portion thereof.
4. Structure as set forth in claim 1 wherein said supporting means
comprises a corbel or floor integral with said one segment and extending
inwardly therefrom, said corbel or floor adapted to be coupled in
supporting relationship to the ore crusher.
5. Structure as set forth in claim 1 wherein the segments have
cylindrical portions throughout substantially their entire length,
the diameters of the cylindrical portion of said first segment being
different from the diameter of the cylindrical portion of the second
segment.
6. Structure as set forth in claim 1 wherein said wall is in a
generally vertical plane.
7. Structure as set forth in claim 6 wherein said wall has a pair
of opposed, generally flat faces and a pair of side margins, the
sections being integral with said wall at said side margins.
8. Structure for mounting an ore crusher and associated ore handling
equipment comprising: a housing of reinforced concrete adapted to
be disposed below ground level and having a pair of interconnected,
tubular segments defining in plan form a generally figure eight
configuration therefor, each segment having a convex outer surface,
one of the segments having first means for supporting an ore crusher,
an opening for receiving feed ore, a space for receiving crushed
ore from the crusher, and second means for mounting a feeder aligned
with said space, the other segment having third means for supporting
the crusher drive motor, fourth means for mounting an elevator therein
and fifth means for mounting an inclined ore conveyor aligned with
one end of the feeder.
9. Structure as set forth in claim 8 wherein said first and third
means include corbels integral with said segments and supported
directly thereby.
10. Structure as set forth in claim 8 wherein said fifth means
includes an inclined tube integral with the other segment at the
lower end thereof, the tube being in communication with the other
segment to permit the ore conveyor to extend from said other segment
into and through said tube.
11. Ore handling apparatus comprising: a housing of reinforced
concrete and having a pair of generally hollow tubular segments
and a wall interconnecting the intersecting ends of said segments,
each segment having a convex outer surface, said segments and said
wall being integral, and said segments and said wall defining in
plan form a generally figure eight configuration for the housing,
said housing adapted to be disposed in the ground with the upper
ends of the segments being adjacent to ground level, one of the
segments having an open, upper, ore-receiving end; an ore crusher;
means mounting the ore crusher in said one segment below the upper
end thereof; a first, generally horizontal feeder in said one segment
below the ore crusher and extending into the other segment; an inclined
conveyor in the other segment and extending outwardly therefrom,
said conveyor having a lower end aligned with and disposed below
the proximal end of the first feeder; elevator means in the second
segment between the upper and lower ends thereof; and access hatches
through the floors of the second segment for entry and removal of
mechanical and electrical parts.
12. Apparatus as set forth in claim 11 wherein said crusher mounting
means includes a corbel or floor integral with said one segment
and extending inwardly from the inner surface thereof.
13. Apparatus as set forth in claim 11 wherein is included a drive
motor having a drive shaft, means in said other segment for mounting
the drive motor therein, said wall having an opening therein, said
drive shaft extending through said opening and being coupled to
said ore crusher for actuating the same.
14. Apparatus as set forth in claim 11 wherein each segment is
tranversely circular throughout a major portion thereof.
15. Apparatus as set forth in claim 11 wherein at least one of
the segments is transversely elliptical throughout a major portion
thereof.
16. Apparatus as set forth in claim 8 wherein at least one of
the segments is transversely circular throughout a major portion
of the cross section thereof.
17. Apparatus as set forth in claim 8 wherein at least one of
the segments is transversely elliptical throughout a major portion
of the cross section thereof.
Description This invention relates to improvements in the embedded housing
of ore crushers and associated equipment and, more particularly,
to an embedded crusher housing which requires only a minimum of
concrete and reinforcing steel and which utilizes the interior space
thereof more efficiently than is capable with conventional housing
structures.
BACKGROUND OF THE INVENTION
It is well-known to provide an ore crusher in a rectangular, box-shaped
embedded housing of reinforced concrete. This permits heavy haul
ore trucks to dump their contents into a hole in the ground to eliminate
the need for elevating the uncrushed ore to a height which would
require considerable work to do so. the rectangular configuration
of such a housing requires that a considerable amount of concrete
and reinforcing steel be used to render the housing structurally
sound but yet large enough to house not only the crusher itself
but also other equipment and chambers, such as an elevator, a surge
pocket, a conveyor, drive machinery and the like. Moreover, in the
construction of a rectangular housing of conventional design, considerable
expense is always encountered in the placement of the large amount
of reinforcing steel that is required. Also, a problem exists in
properly pouring concrete around the closely spaced reinforcing
steel to form the rectangular wall of the housing.
An attempt to reduce the amount of concrete and reinforcing steel
in housing of this type has resulted in the development of a housing
having a single circular shape, such as a standard silo shape. This
shape, when considered from a structural point of view, offers great
promise because the exterior wall of concrete is stressed in its
most efficient manner, i.e., as a closed ring in compression. Such
a structure has an ability to resist the very high lateral pressures
resulting from earth backfill as well as the surcharge from heavy
haul trucks. The single circle configuration offers a significant
savings in materials when compared with the heavy slab-beam-strut
concept used in the conventional rectangular crusher housing and
the massive use of concrete and reinforcing steel of such rectangular
housing. These savings result from a reduction of average exterior
wall thickness of three to four feet as required by the rectangular
structure to a minimum of eighteen to twenty-four inches for the
single circular configuration. In addition, significant savings
in reinforcing steel are achieved due to the concept of carrying
principal loads by concrete in compression instead of bending in
heavy slabs.
While the single circular shape of pressure housing has certain
advantages, it does not provide for the optimum use of the space
therein. This drawback requires that the single circular housing
be relatively large in size, thereby requiring large amounts of
concrete and reinforcing steel although such amounts are less than
those required in the conventional rectangular housings.
Because of the foregoing, a need has arisen for an improved underground
crusher housing which utilizes the structural features of the single
circular configuration of housing yet further minimizes the concrete
and reinforcing steel required to provide a structurally sound housing
yet provide for adequate space to contain all of the necessary equipment
to carry out ore crushing operation.
SUMMARY OF THE INVENTION
The present invention is directed to an improved housing for the
underground mounting of an ore crusher and its associated equipment.
To this end, the housing has a generally figure-eight configuration
in plan, defined by a pair of intersecting, hollow, upright, generally
cylindrical segments with a common wall between the points of intersection
of the segments. The intersecting cylinders will be usually but
not necessarily circular cylinders. Structural requirements make
circular cylinders preferable but the arrangement of machinery within
the housing and size limitations may make an eliptical cylinder
preferable for one or both segments. One of the segments is adapted
to contain the dump pocket, the ore crusher, the surge pocket, and
a lateral discharge feeder; whereas, the other segment is adapted
to contain equipment such as an elevator and elevator shaft, an
inclined conveyor leading off through an inclined tube communicating
with the lower end of the other section, dust control apparatus,
lubrication system, and other service facilities. The intersecting
cylindrical configurations of the segments with the common wall
allow the housing, which is formed of reinforced concrete, to provide
the most efficient resistance to the high lateral pressures resulting
from earth backfill and the surcharge from heavy haul ore trucks,
while allowing for the optimum of the space in the housing, thereby
keeping the size of the housing relatively small to minimize the
volume of concrete and the amount of reinforcing steel which must
be used to form the housing.
Another aspect of the housing of this invention is the way in which
the ore crusher and other equipment and feed ore and crushed ore
are supported in the segments. The segment of the housing containing
the crusher is provided with a floor or corbel extending inwardly
from the inner surface of the segment and supported directly from
the segment wall and the common wall and the ore crusher is supported
on the floor or corbel and extends through a central opening therein.
This feature eliminates the need for columns, beams and the like
which have heretofore been used to support the crusher in conventional
rectangular and single circular ore crushing housings. Other floors
and corbels similarly supported directly fom the housing walls provide
support for the other equipment, the feed ore and the crushed ore
without the use of columns, beams and the like.
The present invention, therefore, meets needs caused by deficiencies
of prior art ore crusher housing and assures that a stable, structurally
sound construction can be achieved with a minimum of concrete and
reinforcing steel while providing optimum usage of the space within
the two sections of the housing. Significant savings in material
costs can, therefore, be realized, yet all of the operating advantages
of prior art housings can be provided in the housing of the present
invention.
The primary object of this invention is to provide an improved
embedded housing for an ore crusher, wherein the housing can be
constructed with significantly less concrete and reinforcing steel
than is required in the construction of conventional housings.
Another object of this invention is to provide a housing of the
type described wherein the housing has a generally figure-eight
configuration in plan defined by a pair of intersecting hollow,
upright, cylindrical segments with a common wall between the points
of intersection of the segments so that the configuration presents
the most efficient manner of stressing the concrete defining the
segments so as to resist the relatively high lateral pressures exerted
on the housing due to earth backfill and the surcharge from heavy
haul ore trucks.
Other objects of this invention will become apparent as the following
specification progresses, reference being had to the accompanying
drawings for an illustration of the invention.
In the drawings:
FIG. 1 is a vertical section through the underground housing for
an ore crusher forming the subject of the present invention;
FIG. 2 is a top plan view of the housing looking in the direction
of line 2--2 of FIG. 1;
FIGS. 3 4 and 5 are horizontal sections taken through lines 3--3
4--4 and 5--5 respectively, of FIG. 1; and
FIG. 3a is a view similar to FIG. 3 but showing elliptical housing
segments.
The underground housing of the present invention is broadly denoted
by the numeral 10 and has a figure eight configuration in plan form
as shown in FIGS. 2-5. The housing is made up of two cylindrical
segments 12 and 14 which are interconnected by a common wall 16.
The figures show circular cylinders but other cylindrical shapes
might be preferable in certain circumstances, such as elliptical
cross sections as shown in FIG. 3a. Segments 12 and 14 are not completely
cylindrical in that wall 16 which lies in a generally vertical
plane, forms a closure across the open end segment. Segment 12 has
a diameter less than segment 14 and, as shown in FIG. 1 segment
12 is slightly higher in elevation than segment 14 the latter having
its upper extremities substantially flush with ground level 18.
An ore crusher 20 of conventional construction is located in segment
12 near the upper end thereof. Crusher 20 is supported laterally
by a floor or corbel 22 and extends through an opening 24 in the
floor. The crusher is also supported on a second floor or corbel
26 spaced below floor 22. Floors or corbels 22 and 26 are integral
with segment 12 and wall 16 and project inwardly therefrom. This
construction avoids the need for vertical columns for supporting
the crusher as is required in many prior art crusher housings. Crusher
20 also has an ore discharge passage 28 which is a central opening
in floor 26.
The area above floor 22 and the top of the crusher receives ore
from trucks. When trucks of about 150 tons or larger capacity are
used, this area may take a square or rectangular configuration to
prevent trucks from dumping directly on the crusher upper bearing
support.
Segment 12 has a third floor or corbel 32 spaced below floor 26
so that a surge pocket 34 is defined between discharge passage 28
of crusher 20 and floor 32 there being a central opening 36 in
floor 32 to allow crushed ore from surge pocket 34 to gravitate
onto a generally horizontal feeder 38 below floor 32 and to pass
through an opening 40 in wall 16 for discharge onto an inclined
conveyor 42 at the bottom of segment 14 (FIG. 1). A fourth floor
44 is located below conveyor 38 and supports it.
Segment 14 has a first floor 50 across the interior thereof at
a location near but slightly below floor 26 of segment 12. Floor
50 has a covered hatch 52 spaced inwardly from the inner surface
of segment 14 for entering and removing mechanical and electrical
parts.
A second floor 54 is provided in segment 14 below floor 50. This
also has a covered hatch 56 generally aligned with hatch 52 thereabove.
Segment 14 is also provided with an elevator shaft 58 which extends
the length of the segment and into a silo or housing 60 supported
on the roof or uppermost floor 62 of segment 14. Silo 60 has a doorway
64 for entrance to the elevator (not shown) in shaft 58. On each
of floors 50 and 54 there is a doorway permitting access to the
elevator in the shaft from each of such floors. Also, there is a
doorway at the bottom of the shaft permitting access to the vicinity
of conveyor 42.
A drive motor 66 is supported on floor 50 and has a drive shaft
68 passing through opening 70 in wall 16 so that the motor can be
coupled with crusher 20 to operate the same for crushing ore.
Floor 54 is provided with a pair of spaced rails 72 (FIG. 4) over
which a utility vehicle 74 can be driven. Also, portable tracks
76 can be moved into a position across the upper portion of surge
pocket 34 so that vehicle 74 can be driven into the surge pocket
to allow workmen to do maintenance work on crusher 20 from beneath
the latter, An opening 78 is provided in wall 16 to allow vehicle
74 to move through the wall.
The upper level of the crushed ore in surge pocket 34 can be detected
by a unit comprised of a radiation source 80 and a radiation detector
82 generally horizontally aligned with each other. Radiation source
80 is adjustably mounted in a pipe 84 embedded in floor 26 and in
the wall structure of section 12 as shown in FIG. 1. Pipe 84 extends
between floors 26 and 32 and any suitable means can be utilized,
such as a flexible line or the like, to adjustably position radiation
source 80 in pipe 84. Radiation detector 82 can be manually positioned
in opening 78 so that the radiation detector is in alignment with
radiation source 80.
In addition to supporting silo 60 roof 62 also supports a housing
85 which forms a control room for operating crusher 20 and conveyors
38 and 42. Roof 62 also has a pair of covered hatches 86 and 88
hatch 86 being vertically aligned with hatches 52 and 56. A housing
90 to one side of segment 14 defines an electrical room housing
control panels and other electrical equipment.
In use, a truck or other vehicle containing ore to be crushed moves
over surface 18 and dumps the ore into the open top 92 of segment
12. The ore falls through segment 12 and into crusher 20 where it
is crushed when motor 66 is operating. The crushed ore falls into
surge pocket 34 and then passes through opening 36 in floor 32 for
deposit onto feeder 38. The ore on feeder 38 is then moved at controlled
rate to the left when viewing FIG. 1 and gravitates eventually onto
inclined conveyor 42 and up the conveyor a relatively long distance
to ground level 18. Typically, conveyor 42 will extend above ground
level 18 to a processing station spaced thereabove.
Typical dimensions of the various components of housing 10 are
as follows: the wall thickness of segments 12 and 14 is 24 inches
or less; the diameter of segment 12 is 28 feet; the diameter of
segment 14 is 36 feet; the distance from ground level 18 to the
upper surface of base 48 is 87 feet. Motor 66 is a 500 hp motor.
Crusher 20 is a 60 inch .times. 89 inch crusher. The distance between
the center line of segment 12 and the center line of segment 14
is 30 feet. The thickness of floor 22 is 42 inches. The minimum
thickness of floor 26 is 60 inches. The thickness of floor 32 is
30 inches and the thickness of base 48 is 48 inches. The thickness
of each of floors 50 and 54 is 18 inches. Conveyor 38 is 7 feet
wide and 30 feet long. Conveyor 42 is 5 feet wide.
The construction of housing 10 permits the use of a minimum volume
of concrete and a minimum amount of reinforcing steel because the
cylindrical cross sections of segments 12 and 14 permit housing
10 to be stressed in its most efficient manner, i.e., as closed
ring segments in compression or as closed elliptical cylindrical
segments in compression with moderate bending. This assures that
housing 10 even when it has a height of 80 feet to 100 feet, has
the ability to resist the very high lateral pressures exerted thereon
from earth backfill as well as the surcharge from heavy haul trucks.
Also, the configuration of housing 10 permits a more efficient utilization
of space since it allows the crusher, surge pocket, and discharge
conveyor to be in one segment while drive machinery, dust control,
lubrication systems, hoistways and elevator can be in another segment.
The same principle of utilizing in a circular concrete building
the basic strength of concrete in compression is retained by the
figure eight configuration of housing 10.
Prior art crusher housings of rectangular and single circular plan
forms can be compared in cost with the cost of housing 10 by comparing
the amount of concrete and reinforcing steel used in each. The comparison
figures are as follows:
______________________________________ Reinforced Steel, Avg. Planform
Concrete Reinforcing Unit Wt. Configuration Cubic Yards Steel, Tons
Lbs/Cubic Yards ______________________________________ Rectangular
3396 345.5 203 Single Circle 2285 194 170 Figure Eight 1691 137
162 ______________________________________
These quantities are for housings in which the same gyratory crusher
(60 inch .times. 89 inch) is installed. The specific requirements
of individual users might result in a change in the total amounts
of concrete and reinforcing steel required for the rectangular,
the circular of figure eight structure. The quantities shown above
include reasonable allowances for changes resulting from minor variations
in layout.
Based on unit costs as of October 1974 for concrete and reinforcing
steel of approximately $130 per cubic yard and approximately $650
per ton in place, respectively, the quantities shown above can be
extended on a cost basis as follows:
______________________________________ Planform Configuration Concrete
Reinforcing Steel Total ______________________________________ Rectangular
$441480 $224575 $666055 Single Circle $297500 $126100 $423600
Figure Eight $219830 $89050 $308880 ______________________________________
Considering the method of excavation employed for these underground
structures which typically involves the use of heavy earth moving
equipment and blasting techniques to create a generous and open
site for concrete work, the cost of excavation is considered the
same for all three types of structures and, therefore, is excluded
from the above comparison.
While several different construction techniques are available and
can be used to form housing 10 of the present invention, a preferred
technique is the one using slip forms. This technique has the desirable
feature of achieving the construction of the basic, external structure
of housing 10 in a minimum of time. The technique is also advantageous
at construction sites located in colder climates where it is desirable
to create a complete exterior enclosure as soon as possible and
then to complete the interior features under cover at a time when
climatic conditions would severely hamper outside work. Combined
with the low unit cost of slip-forming the use of permanent metal
form-support systems is desirable for constructing the interior
floor levels which provides for an expeditious floor pouring schedule
to minimize overall costs.
With respect to the question of whether or not the slip form technique
is suitable for achieving a solid and substantial finished structure,
such as required to support a large piece of moving equipment like
a gyratory crusher, it is to be pointed out that features have been
developed in housing 10 to satisfy the requirement for such a solid
and substantial finished structure. For instance, the thickness
of the walls of sections 12 and 14 is preferably about 24 inches.
This serves a three-fold purpose of providing ample tolerance for
the slip-form technique, additional mass for supporting the machinery
and adequate thickness to provide for substantial keyways used to
support horizontal elements. In combination with such keyways, grouting
techniques can be used to insure that a positive bond between walls
and floors is achieved.
In regions having a high water table, the problem of buoyancy of
housing 10 might be of concern. The reason for this is that the
reduced wall thickness of the figure eight configuration of housing
10 serves to reduce the total dead weight of the structure whem
compared with the dead weight of structures of rectangular configuration.
Resistance to buoyancy can be achieved by extending base 48 laterally
beyond the outer surfaces of sections 12 and 14 as shown in FIG.
1 so that the backfill above the extension 98 will provide suitable
anchorage of housing 10 within the ground.
It appears that a potential saving in civil engineering design
man-hours is possible using the figure eight concept due to the
simplified structural features thereof. This fact is evident because
the elaborate analyses and detailing required for designing slab
and beam retaining walls is simplified with the figure eight configuration.
Electrical, instrumentation and mechanical effort would not require
an increase in man-hours over that required with the use of the
rectangular configuration . |