Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
In known air classification systems unclassified mi~ed
materials may be deposited by a suitable feed conveyor into the
lower inlet end of an inclined rotating air classifier drum. As
the drum rotates, a stream of air is forcefully directed through
the drum and entrains light weight, light density materials which
comprise part of the mi~ture and carries them out the raised dis-
charge end of the drum into a suitable storage area such as a ple-
num, cyclone or silo. The materials which are too heavy or too
dense to be entrained are tumbled by the rotation of the drum and
eventually work their way back out the lower inlet end of the drum
onto suitable conveyor means which removes them for subsequent
processing or storage.
Such air classification systems are becoming popular in
municipal waste handling installations where a great variety of
materials are mixed together. For example, paper fabric, plastic,
glass and wood are mixed with metal which may compTise small items
such as coins to large items such as iron castings, for examples.
Sometimes the mixture is predominantly comprised of the heavy
items and at other times the light items predominate.
When heavy items are predominant, they tend to clog the drum
unless the feed rate is reduced since heavy items must work their
; way gradually down the inclined drum. When light items predomi-
nate, separation is difficult unless the velocity of the air
stream passing through the drum is increased.
One known attempt to solve this problem has been disclosed
in U. S. patent No. 3,970,547~which teaches a system wherein the
~g
feed conveyor is movable a~iaily within ~,:he drum to adjust ~he
longitudinal position within the dTum at which the materials are
deposited. However, while this has provided some improvement, it
has not been entirely success~ul.
# ~ Th c ~J o Y ~ o J o n ~ ~ L~ 19 7
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89~96
Summary of the Invention
The above and other objections to and disadvantages of
~<nown rotary drum air classifier systems are overcome by the
present invention wherein there is employed a feed conveyor
means which is adjustable axially of a rotary drum and also
adjustable laterally and vertically of the drum. This is accom-
plished by mounting the conveyor and feed hopper upon a suitable
undercarriage which is itself vertically movable and is comprised
of portions which are slidable whereby lateral and axial movement
are accomplished. ~ovement of the various adjustable parts of
the undercarriage is accomplished by a number of hydraulic actua-
tors or other devices so that adjustments in the three directions
are performed independently. In one embodiment the conveyor is
preferably fixed to a first section which is movable laterally of
the drum upon a second section. A third section carries the first
and second sections and is movable axially of the drum together
theTewith and with the conveyor. The third section forms a part
of a vertically adjustable carriage whereby, when such veTtical
adjustment is effected, it will move up or down together with the
first and second sections and the conveyor.
Since the mixture of materials being classified is usually
predominantly comprised of either heavy or light materials, the
conveyoT will rarely be located on the axis of the drum. If the
materials comprise predominantly heavy items, the conveyor will
preferably be withdrawn toward the inlet end of the drum so as to
discharge usually within the first third of its length, and will
be preferably located slightly nearer the rising side wall of the
drum. This will effectively facilitate the removal of the
relatively large amounts of heavy materials.
~f the mixture of materials comprises predominantly light
39396
items, the conveyor will be positioned preferably farther inwardly of the
drum and above the drum's longitudinal axis. This enables the light
materials to be more effectively engaged by the air stream as they fall a
greater distance from the conveyor toward the bottom of the drum.
In accordance with the present invention there is provided an
adjustable conveyor-supporting apparatus including a conveyor operably
extending parallel with a known axis, and means for adjusting said conveyor
with respect to said known axis comprising the combination of a base comprised
of a pair of spaced parallel base members located parallel with said axis,
a first support comprising a base frame mounted on the base members and
movable longitudinally thereon in a direction parallel to said axis, a second
support comprising a pair of spaced parallel lateral rails mounted on said
base frame and extending laterally in a direction perpendicular to said axis,
said lateral rails being movable vertically with respect to said axis indepen-
dent of said first support, and conveyor support means mounted on said
lateral rails and movable thereon in a direction transverse to said axis,
said conveyor being mounted on said conveyor support means and movable there-
with and extending in a direction parallel to said axis.
In accordance with the present inYention there is also provided
in a rotary drum classifier system, adjustable conveyor-supporting apparatus
including a conveyor operably extending parallel with a ~nown longitudinal
axis of a rotary drum, and means for adjusting said conveyor with respect
to said axis comprising the combination of a base comprised of a pair of
spaced paTallel base members extending in a direction parallel to said axis,
a fiTst support comprising a base frame mounted on the base members and
movable longitudinally thereon in a direction parallel to said axis, a
second support comprising a pair of spaced parallel lateral rails mounted on
said base frame and extending laterally in a direction perpendicular to said
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axis, said lateral ~ails being movable vertically with respect to said
axis independent of said first support, and conveyor support means mounted
on said lateral rails and movable thereon in a direction transverse to ~id
axis, said conveyor being mounted on said support means and extending in a
direction parallel to said axis and movable with said support means toward
and away from one end of said drum. .:
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Brief Description of the Dra~ings
The above and other objectives and advantages of this
lnvention will become apparent from the following description
taken in connection with the accompanying drawings wherein:
Fig. 1 is an isometric view of a rotary drum air classifier
system embodying the invention;
Fig. 2 is a side elevational view of the system shown in
Fig. l;
Fig. 3 is an enlarged perspective view of the adjustable
conveyor-supporting structure;
Fig. 4 is an end view of the structure shown in Fig. 3
showing a modi~ied supporting carriage; and
Fig. 5 is a diagram illustrating the x-y-z adjustability
of the conveyor system of the invention.
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16~89396
Description of the Preferred Embodiments
Referring more particularly to the drawings wherein like
characters of reference designate like parts throughout the
several views, the apparatus shown in Fig. 1 includes a number of
cooperating devices arranged to process and separate materials
automatically, these pieces of apparatus being parts of a complete
waste resource separating and recovery system.
A feed hopper 10 receives unclassified waste or other mixture
of materials from one end of an adjacent supply conveyor 12. The
hopper 10 is mounted as by brackets 14 on a first frame 16 which
comprises a pair of spaced parallel longitudinally extending rails
18 secured together by suitable cross members 19. The hopper 10
is raised sufficiently above the frame 16 to permit a longitudi-
nally extending feed conveyor 20 to be disposed beneath the hopper
and preferably between the rails 18. The conveyor 20, as shown in
Fig. 1, may be suitably supported on the rails 18 as by mounting
its drums 22 on a shaft which is journaled at its opposite ends
in the rails 18. A motor 24 with conventional belt and pulley
drive mechanism 25 is utilized for moving the conveyor belt in a
well-known manner.
The feed conveyor 20 projects into the interior of a horizon-
tally disposed rotary air classifier drum 26 and is adapted to
receive mixed materials to be classified from the bottom OI the
hopper and propel them into the drum. The materials have prefer-
ably been shredded to a size not exceeding about twelve inches,
and the drum classifier separates the shredded materials in the
known fashion of apparatus of this character. The drum 26 is
angled at a selected inclination, such as 10, for example, and
air is caused to flow through it at high velocity by means of a
fan or blower 28 which may be suitably mounted on a plenum,
cyclone or similar collecting chamber 30 into the higher end of
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which the drum projects.
As raw mixed materials drop from the end of the feed convey-
or 20 onto the bottom of the drum wall, the heavy materials in
the mixture will be rotated upwardly with the drum to a point
where they will fall to a lower point within the drum. Such tum-
bling action is repeated until eventually the heavy materials
fall out of the lower end of the drum through a chute 32 onto
another conveyor 33 which will carry them away for further pro-
cessing or disposal. The light materials will be entrained with-
in the high velocity air stream and will be carried out the upper
end of the drum 26 into the collection chamber 30 from which they
may be subsequently removed by a conveyor 31 to a remote location
for further processing, such as being converted into a refuse
derived fuel, for example.
It is to be understood that the feed conveyor 20, which is
illustrated herein as a belt-type device, may take other forms
such as, for example, a screw feed as disclosed in aforementioned
U. S. patent 3,970,547 which is owned by the same assignee as
the present invention.
Any suitable means may be used to rotate the drum 25. In
Figs. 1 and 2 this means comprises a circumferential sprocket
wheel 34 which is fixed around the drum at a point midway of its
length and which meshes with a small sprocket wheel 36 rotatably
mounted on one end of a reduction gear box 38. The gear box 38
is interconnected with a drive motor 40 whereby rotation of the
drum is accomplished.
The drum 26 is supported upon a plal:form 42 by means such as
a pair of rollers 44 which each engage a respective restraining
ring or collar 46, the rings being fixed to and extending around
the circumference of the drum near opposite ends thereof. The
rollers 44 have flanges on their sides which engage opposite sides
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~f the respective ring 46 to prevent longitudinal movement of
the drum as it is rotated.
The platform 42 is pivotally supported at one end beneath
the conveyor by vertically adjustable support means 48 and at its
opposite end it is pivotally mounted by a bearing 50 on the upper
end of a fixed support 52. The platform 42 and consequently the
drum 26, together with the conveyor apparatus may be angled to
a selected inclination, such as 10, for example, by raising or
lowering about the axis of the bearing 50.
It will be apparent that variations in the angle of inclina-
tion of the drum and variations in the velocity of the air flow
through the drum will cause changes in the ratio of lights to
heavies during a separation process. However, other factors also
must necessarily be considered when attempting to achieve effi-
cient desired classification of the mixed materials.
For example, the predominance of heavy materials in a mix-
ture will sometimes cause the drum to become clogged or otherwise
will prevent ready separation of light materials. Regulation of
air flow has little ef-fect on most heavy items, and regulation
of the drum's angle of inclination may decrease the separation
efficiency. Slowing of the feed conveyor to overcome such a
problem may cause undesirable backlogging of unclassified
materials.
The predominance of light materials in a mixture will some-
times produce unsatisfactory separation since incTease of air
velocity may cause an undesirable amount of heavies to be
entrained and removed with the lights.
The aforementioned patent 3,970,547 teaches that a conveyor
is positioned on the axis of a rotary drum and may be moved
axially thereof in order to select the longitudinal position
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within the drum at which material is deposited.
~n earlier U. S. patent, ~o. 3,804,249~ teaches that material
should be deposited in the longitudinally central portion of
the drum. ~either of these patented apparatus completely solve
the problems enumerated above.
In accordance with the present invention the conveyor is
mounted for universal, that is, for axial, lateral and vertical
adjustment with respect to the axis of the drum, and when properly
adjusted the conveyor will feed mixed waste materials into the
drum at a location which achieves a selected ratio of lights to
heavies separation without requiring variation in angle of drum
inclination or in velocity of air flow. Such adjustment of the
conveyor allows mixed materials to be fed into the drum at an
optimum location depending upon the predominance of light or
heavy materials in the mixture being classified.
It has been found that when a mixture is comprised predomi-
nantly of heavy materials, the best separation is achieved when
the discharge end of the conveyor is located relatively near the
inlet end of the drum, below the drum's axis and somewhat nearer
the rising side wall of the drum. In this position the heavy
items will have a short path to follow in tumbling down and out
the drum, thus preventing clogging which otherwise might occur.
Furthermore, the heavy items are more quickly lifted by the rising
side wall of the drum than would occur if the conveyor was posi-
tioned nearer the falling side wall. This also aids in the
prevention of clogging.
When the mixture is comprised predominantly of light items,
it has been found that the conveyor will be preferably located
above the axis of the drum at almost any point along the length
of the drum. This will enable the air stream to make most
~ (~G;~ s ~t- ai) issu-J on ~ bJ I 9qlt
1~15193~t6
effective contact with the mass of light materials, entraining
~hem and ef iciently conducting them into the collection chamber.
The platform 42 which carries the conveyor supporting and
adjusting mechanism includes a pair of spaced base rails 54 which
are interconnected by cross members 56 as best shown in Fig. 3.
An adjustable carriage 58 is mounted on the platform and includes
an upper and a lower frame 60 and 62 respectively. Lower frame
62 comprises a pair of spaced parallel longitudinally extending
I-beams 64 interconnected by cross members 66. The upper frame
60 similarly comprises a pair of spaced parallel longitudinally
e~tending channel members 68 interconnected by cross members 70.
Extending upwardly between the frames 60 and 62 on either
side thereof is a pair of cTossed arms 72 and 73 which are pivot-
ally mounted at their crossover points on an interconnecting
shaft 74. The I-beams 64 are positioned with channels therein
opening upwardly, while the channels in upper channel members 68
open downwardly. The lower end of arms 72 are pivotally mounted
within the channel near one end of one of the lower members 64
and has its upper end slidably mounted as by a pin and slot con-
nection 76 in the channel near the opposite end of the uppermember 68. The other arm 73 is similarly mounted with its upper
end pivoted to one end of upper member 68 and its lower end
slidably connected by pin and slot connection 78 to the opposite
end of lower member 64.
Thus, the upper frame 60 may move up and down toward and
away from the lower frame 62 and the arms 72-73 will perform a
scissoring action to retain the frames in the desired respective
relations. Such movement of upper frame 60 may be accomplished
by any suitable means such as a hydraulic piston 80 which is
mounted on a cross member 56 of the lower frame 62 and has its
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piston rod 82 connected to a cross member 70 of the upper frame
60. The piston 80 may be actuated by any suitable means (not
shown) to raise and lower the upper frame 60.
The carriage 58 is adapted to slide toward and away from the
drum 26 on the rails 54 which interfit into the bottom channels
of the I-beams ~ for this purpose, as shown in Fig. 4. Thrust
bearings 84 are provided as shown to locate the members 64 on
rails 54. To move the carriage 58 along the rails 54 there is
provided a hydraulic or other device 86, similar to lifting device
80 which is mounted on a plate 88 fixed to the ends of rails 54
as shown in Fig. 3. The piston rod 90 of device 86 is attached
to one of the cross members 66 of the lower frame 62 so that when
the hydraulic device 86 is operated, rod 90 will move to push or
pull the frame 62 and consequently the entire carriage 58 and
parts of the apparatus thereon.
Fixed to the upper end of the carriage 58, as by welding to
members 68 of the upper frame 60, are a pair of spaced perpen-
dicularly extending rails 92 which are provided on their upper
suTfaces with a selected shape to accomodate rollers 94 which are
carried by a pair of spaced parallel rails 96 which overlie and
ride along the rails 92 in a direction laterally with respect to
the drum's axis.
The hopper-and-conveyor-supporting frame 16 is fixedly
mounted by its rails 18 on the rails 96 as by welding. Thus, by
means of the rollers 94 the frames 96 and 16 may be moved lateral-
ly of the structure together with the hopper 10 and conveyor 20.
Such lateral adjustment of the conveyor may be effected by any
~suitable means such as by a hydraulic device ~ which is fixed
~~upon a supporting plate 100 carried by frame 96, the piston rod
102 of the hydraulic device 98 being attached to a rail 18 for
moving the frame 16 as desired.
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`l39396
From the foregoing it will be understood that when the
conveyor 20 is to be adjusted axially of the drum, device 80 will
be operated to move the carriage 58 along the rails together with
the structure thereon including the conveyor.
If the conveyor is to be moved vertically, device 80 is
operated to move the frame 60 together with the structure thereon.
If lateTal adjustment of the conveyor is desired, device 98 will
be operated to slide rails 18 and frame 96 along rails 92.
Such x-y-z adjustment of the conveyor is diagrammatically
illustrated in Fig. 5 wherein item 26 represents the drum, A is
the axis, and x,y, and z respectively indicate axial, vertical
and lateral directions of adjustment. It will be apparent that
such adjustments may be performed independently or simultaneously.
In the embodiment shown in Fig. 4, the scissor-type carriage
has been replaced by four vertically extending corner posts 104
which are fixed to and extend upwardly from the lower frame 62,
the posts 104 and slide vertically thereover. Thus, when the
hydraulic device 80 is operated, the upper frame 60 will rise or
fall together with posts 106. When the device is located at the
desired level, the posts 106 and 104 are locked together by
positioning pins within comating holes therein, in a well-known
manner.
The foregoing description is believed to fully set forth
sufficient details of the invention. However, it will be apparent
that vaTious modifications and changes may be made by those skilled
in the art without departing from the spirit of the invention as
expressed in the accompanying claims. For example, the described
hydraulic actuating devices 80, 86, and 98 may be pneumatic
devices or may be motor-operated, if desired. Therefore, it is
to be understood that all matter shown and described is to be
interpreted as illustrative and not in a limiting sense.
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