Note: Descriptions are shown in the official language in which they were submitted.
2068935
This invention relates to waste recycling and
apparatus and processes for separating ferrous, glass,
plastic and aluminum articles from a commingled stream of
such articles. More particularly, this invention relates to
the separation of commingled plastic and aluminum articles
from an air stream conveying such articles.
Many recycling projects are now underway across
the United States as a way of protecting the environment
from excessive waste disposal. Such processes generally
involve the separation and collection of waste articles of
similar materials at a "MRF" or Material Recovery Facilitv,
and their recycling with similar materials into new goods.
In general, waste products of the type here
considered are those made of ferrous, glass, plastic and
aluminum. These include for example, steel and tin cans;
206893~
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amber, green and clear (or flint) glass; plastic bottles,
jugs and containers and aluminum cans.
While various existing projects involve individual
persons separating various articles into separate containers
s at the point the articles are used, a major difficulty is
currently presented by the desire to separate and collect
such components from huge agglomerations of non-separated or
commingled waste products. It has been highly desirable to
provide a process by which the various components of such
agglomerations can be efficiently separated and collected at
flow rates and costs which render such processes economical-
ly feasible.
In the past, separation of such agglomerated
components has been achieved by time consuming, expensive
methods. For example, separation has been done manually, a
process which is far too time-consuming and costly. In
another method, a stream of commingled articles has been
dropped through the air while air streams are directed
across the articles to blow the lighter ones away from the
heavier falling articles, much in the same manner as the
biblical process of removing chaff from wheat by casting the
mix to the winds. In stlll another process, heavy chains
were drug across a commingled stream of articles to drag off
the lighter plastic and aluminum articles from the heavier
glass and metal. All these processes are either very
expensive and/or do not provide the separation flow-through
rates desired. Still other processes have not been entirely
satisfactory or sufficiently cost efficient.
206893~
Many forms of apparatus and processes have been
used in the past to classify finer or lighter from heavier
particles or materials in other industries. Such other
apparatus and processes are not believed suitable for sepa-
ration of ferrous, glass, plastic and aluminum articles.one such prior device is the pneumatic tobacco classifier
shown in U.S. Patent No. 4,915,824. In such device, inter-
mixed light leaf and heavier stem tobacco particles are cast
across a chamber in an arc-shaped projected stream. Air
streams of varying velocities are directed against the
stream to separate the lights from heavier particles. The
heavier particles fall into a discharge chute across the
chamber, while the lights are carried by the air to a
centrifugal separator and are discharged through an air
lock.
Such apparatus has worked well for tobacco parti-
cles but would not be suitable for separating ferrous,
glass, plastic and aluminum articles of the sizes and
weights normally encountered in an agglomeration of waste
materials which must be separated for recycling. Projection
of a commingled stream of such articles would cause breakage
of the glass, and it is not apparent that certain components
could be separated from others in such a system. Also,
agglomerations of recyclable waste materials typically
include undesirable residue materials in a vast array of
sizes and weights. Such residue materials must also be
separated from the ferrous, glass, plastic and aluminum
articles. Thus, apparatus for separation of other products
2068935
--4~
is not helpful to or suggestive of apparatus or methods for
handling recyclable articles of the type noted.
In the prior patent application, new apparatus and
methods were disclosed for separating ferrous, glass,
plastic and aluminum articles from a commingled stream of
such agglomerated articles. A portion of that apparatus
operated to separate lighter aluminum and plastic articles
from heavier glass articles by means of a closed-loop air
stream. These aluminum and plastic articles were then
separated out of the air stream loop in a separator for
further separation, while the purged air stream was directed
back to a blower inlet. It is now desirable to provide
separators of even more efficiency for separating the lifted
plastic and aluminum articles from the closed loop air
stream.
Accordingly, it has been one objective of this
invention to provide improved apparatus and methods for use
in separating ferrous, glass, plastic and aluminum articles
from a commingled stream of such agglomerated articles.
A further objective of this invention has been to
provide improved apparatus and methods for use in separating
aluminum and plastic articles from glass articles, all of
which are presented in a commingled stream of articles.
A further objective of the invention has been to
provide improved separator apparatus and methods for sep-
arating recyclable waste articles entrained in an air stream
from that air stream so the air stream can be reused.
206893~
To these ends, a preferred embodiment of the
invention of this application is useful together with
apparatus for receiving a commingled stream of ferrous,
glass, plastic, aluminum and undefined residue articles, and
for conveying such commingled stream of articles through
progressive separation stations for respectively separating
pluralities of the same kind of articles from the stream so
that different kinds of articles can be separately collect-
ed. Such a commingled stream includes, for example, the
following components:
Ferrous - steel and tin cans
Plastics - High density polyethylene (H.D.P.E.)
such as milk jugs:
Polyethylene terephthalate (P.E.T.)
such as l and 2 liter beverage
containers;
and other plastic articles, i.e.
liquid detergent containers, etc.
Glass - Amber, clear (or flint) and green glass
articles;
Residue - Possibly foreign materials such as
dirt, paper, plastic bags etc.
The commingled stream is first conveyed past
individual operators for manual residue removal and then
past a magnetic separator which removes ferrous materials.
From there the stream is expanded on a vibratory screen for
removal of further residue articles and smaller or mixed
broken glass pieces. The remaining commingled stream of
206893~
glass, plastic and aluminum articles is then concentrated by
a narrowing section of screen conveyor and introduced to a
porous surface conveyor extending across a perpendicularly
moving, upward flowing portion of air traveling in a closed
loop system. The air column lifts lighter plastic and
aluminum articles from glass articles in the stream: the
glass being conveyed beyond the closed loop column where its
components are further separated and collected.
The lifted plastic and aluminum articles travel in
the air column within the closed loop to a separator,
preferably such as the improved separator disclosed herein,
where they are separated from the air stream loop. The
improved separator is particularly useful where the stream
at this point includes light foreign articles such as
plastic bags which the screening separator prevents from
traveling to the fan. The cleared air flow is directed back
to a fan intake from where it is continuously directed onto
the moving commingled stream.
A portion of the air flow is removed or taken off
via a dust skimmer which serves two purposes; one to main-
tain a negative pressure in the closed loop system and
another to skim off dust particles present in the air
stream, thus maintaining a clean air stream.
The discharged plastic and aluminum article stream
at this point comprises primarily large and small plastic
articles and aluminum. These are separated in two phases.
First, the larger plastic articles are separated from the
stream by conveying the stream over a plurality of bars
2~893~
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whieh are spaeed to allow the smaller plastie artieles and
aluminum to drop away from the larger plastie artieles.
These larger artieles are conveyed away from the remaining
eommingled stream.
Sueh plastie and aluminum are alternately separat-
ed at this point by using a trommel which sereens or passes
the aluminum eans, but not the plastie (other than very
small plastie artieles). The resulting aluminum and any
small plastie artieles ean be further separated by an eddy
eurrent separator as mentioned below.
A stream of smaller plastie articles and aluminum
is direeted to the discharge end of a conveyor associated
with an eddy current non-ferrous metal separator. The
plastie articles drop off the end of the conveyor while the
aluminum artieles are kieked out in a flatter trajeetory;
the plastie and aluminum artieles falling on respective
adjaeent parallel conveyors. The aluminum i5 eolleeted,
while the plastie artieles are reeombined with the larger
plastie artieles for respeetive eolleetion after compaction.
Perforation of the plastic, prior to compaction, can be
performed if desired.
The closed loop air flow is particularly useful to
separate plastic and aluminum articles from heavier glass
artieles. While the porous conveyor surface is of suffi-
ciently large area to handle significant stream flow, theascending air column is progressively confined to increase
veloeity, without undue power drain, to effectively remove
and convey plastic and aluminum articles while leaving
206893S
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heavier glass. Use of the centrifugal or screen separator
and closed loop air flow facilitates operation, reduces
effluent, which may contain dust, and facilitates separation
at sufficiently low cost.
The porous surface at the air lift or separation
station is slightly inclined downwardly from upstream to
downstream ends, while the drop to it from the introducing
vibrating screen, and the drop to the glass discharge
conveyor from the porous plate are minimized to reduce glass
breakage.
If desired, the air flow moving upwardly across
the commingled stream can be divided into a plurality of air
streams, each directed across the commingled stream. A
first higher velocity air flow stream contacts the
commingled article stream prior to contact thereof by lower
velocity air flow streams. All such air flow streams
combine in upper portions of the air column for entraining
and conveying lifted plastic and aluminum articles.
Flow rates already attained by the invention have
reached, for example, lo ~o 15 tons per hour with a closed
loop air flow about 3 feet across at interface with the
commingled stream. For this result, an air flow of about
21,000 cfm is used across the commingled stream at a veloci-
ty of about 2100-2300 fpm. The parameters are suitable to
separate constituents of the stream including heavier
plastic articles like liquid detergent bottles. ~n air flow
of about 18,000 cfm is used at a velocity of about 1800-2000
~893~
g
fpm when such heavier plastie articles are not anticipated
in the stream.
A preferred embodiment of the improved separator
for separating the lifted plastic and aluminum articles from
the closed loop air stream includes an enlarged chamber
receiving the entrained articles from a restricted conduit
in which the articles are conveyed at about 4500 fpm. The
enlarged chamber produces a drop in the velocity of the air
stream and entrained articles and the articles drop out of
10- the air stream for discharge, preferably through an air
loek.
The air stream is directed onto a moving porous
eonveyor, which it penetrates, and moves on to the fan or
blower inlet, completing the closed loop. Any lighter
articles, such as paper, plastic bags, etc. which did not
drop out of the air stream are stopped by the porous convey-
or. They are moved in a direction transversely away from
the stream and are discharged into a still air column or
reeeptacle, preferably through another air loek. A scraper
is preferably provided on the return run of the porous
conveyor for removing any remaining residue.
In this way, the air stream is efficiently purged
of plastic and aluminum articles it separated from the glass
and heavier artieles, and as well is effieiently purged of
lighter articles such as paper and lightweight plastic film
or bags.
It will thus be appreciated that the invention
provides improved apparatus and methods for separating
2~6893~
--10--
ferrous, glass, plastic and aluminum articles from each
other for separate collection and subsequent recycling, and
improved apparatus and methods for separating lifted alumi-
num and plastic articles and residue from the closed loop
air stream. Further advantages, details and modifications
will be readily apparent from the following detailed de-
scription of a preferred embodiment and from the drawings in
which:
Fig. 1 is a diagrammatic plan view or flowchart
illustrating the invention;
Fig. 2 is an elevational view taken along lines
2-2 of Fig. 1 and showing further detail of the apparatus
thereof;
Fig. 3 is an elevational view taken along lines
3~3 of Fig 2;
Fig. 4 is a plan view taken along lines 4-4 of
Fig. 3;
Fig. 5 is an elevational view similar to a portion
of Fig. 3, but illustrating diagrammatically features of a
rotating screen separator and an associated "trommel";
Fig. 6 is an elevational side view of the
"trommel" of Fig. 5;
Fig. 7 is a diagrammatic plan view of an alterna-
tive layout of the invention incorporating a closed loop
separator, parts thereof omitted for clarity;
Fig. 8 is a view similar to Fig. 2 but showing
features of a preferred improved air screen separator; and
206g93~
Figs. 9-11 are illustrative elevational views of
further alternative embodiments of an improved air screen
separator.
SYSTEM LAYOUT
Turning now to the drawings, a diagrammatic plan
view of the preferred embodiment of the invention in Fig. 1
illustrates a complete system for receiving a commingled
stream of varying components and for separating and collect-
ing those components. The system 10 receives a commingled
stream of various recyclable ferrous, glass, plastic and
aluminum articles as described above in the summary of the
invention, onto conveyor 11 and is operable to separate the
components and collect like components in large "roll-off"
containers, such as 40 cubic yard roll-off containers which
can be used to transport the articles to recycling facil-
ities. These containers are illustrated at 12-19. As will
be mentioned, container 13 is optional.
Alternately, the separated ferrous, aluminum and
plastic constituents are baled and are discharged for
transfer to recycling facilities.
Container 12 is positioned for receiving ferrous
articles separated by the system 10. Optional roll-off
container 13 is positioned for receiving residue materials
ejected from the system. ~oll-off container 14 is located
to receive aluminum articles. Container 15 is oriented to
receive clear (or flint) glass articles. Container 16 is
oriented to receive green glass articles. Container 17 is
oriented to also receive residue materials. Container 18 is
2068935
-12-
oriented to receive amber glass materials or articles.
Container 19 is oriented to receive plastic articles.
I'he articles making up the commingled stream
generally include ferrous material such as steel and tin
cans, a plurality of different glass articles, such as clear
(or flint), green or amber glass, various ones of which are
used for example, in various beverage and other containers,
plastic articles such as high density polyethylene and
polyethylene terephthalate articles such as found in milk
jugs, soft drink containers and the like, and other plastic
articles such as liquid detergent bottles, and aluminum
articles, such as aluminum cans, together with an residue
materials which have found their way into the agglomeration
of the mixed articles. It will be appreciated that this
lS indiscriminate mixture of articles is retrieved from col-
lection points and can be dumped, for example, on a receiv-
ing floor 20. The articles from there are loaded, such as
by a Bobcat loader, receiving and delivery chute or other
means, onto the receiving conveyor 11.
Receiving conveyor 11 is preferably a chain
conveyor, for example, and is positioned for receiving, as
noted above, the commingled agglomeration of articles and
for conveying them in a commingled stream into the system
10. Other devices and systems for feeding a commingled
?5 stream onto conveyor 11 could be utilized and it will be
appreciated, for example, that partially separated articles
could also be introduced to conveyor 11 for further classi-
fication or separation.
2068935
-13-
From the receiving or loading conveyor 11, the
commingled stream of articles is transferred to an in-line
conveyor 21 which serves to transport the articles from the
receiving area to a first manual sort station 22 when
foreign or residue articles are manually removed. From
there, the remaining commingled stream is transferred to a
ferrous removal station 24 for removing articles containing
ferrous material. The remaining stream is then transferred
to a screening station 26, at which point the remaining
commingled stream comprises generally glass, plastic and
aluminum articles. Further residue is removed therefrom by
passing through a screen at station 26. From the screening
station 26, the remaining commingled stream is introduced to
a closed loop air flow station 28 for removing plastic and
aluminum articles from glass articles. The glass is con-
veyed from station 28 to a glass sort station 30 while the
remaining combined plastic and aluminum articles are lifted
away from glass at station 28, in the closed loop system,
and transferred to a plastic and aluminum separation station
32.
SYSTEM DETAILS
Returning now to the in-line conveyor 21 in Fig.
l, further details of the various separating apparatus and
methods will now be described. As noted, the commingled
stream is conveyed by conveyor 21 to a first sort station
22. First sort station 22 includes a generally horizontal
belt or other type conveyor 36, receiving the commingled
stream from conveyor 21. A plurality or individual
206893~
operators, indicated at 37, are positioned near the conveyor
36, so that as the commingled stream passes, they can
manually remove undesirable residue materials and place them
on the residue conveyor 40. That conveyor 40 extends from
the left- to the right-hand side of Fig. l for conveying and
depositing residue materials into the residue roll-off
container 17.
Conveyor 36 carries the commingled stream beneath
a magnetic ferrous article removal station 24. This station
includes an overhead magnetic belt apparatus 25 with, for
example, a 5 horsepower drive, and can be of any suitable
type. one suitable such unit, for example, is model number
SE 7725, purchased from the Eriez Company of Erie,
Pennsylvania. The magnetic belt of the ferrous removal
station 24 moves in a direction transverse to the machine
direction of the belt conveyor 36. When current is applied,
the apparatus 25 attracts ferrous material in the combined
stream upwardly and away from the remaining articles on
conveyor 36. The ferrous articles are then transferred
through a baler 38 which flattens and compresses the arti-
cles into a bale. The bales may then be discharged onto a
conveyor 39 for transfer into the roll-off container 12 for
steel articles, or simply discharged for loading or transfer
to further ferrous recycling facilities. Any suitable
ferrous article baler can be used.
After passing the ferrous removal station 24, the
combined stream is conveyed to the discharge end 36a of the
conveyor 36 and deposited onto a vibratinq screen conveyor
2068935
41, defining the screening station 26. Screen conveyor 41
has an upstream end 42, which is wider than the discharge
end 44. When the combined stream is discharged from the
discharge end 36a onto the screen 41, the stream of articles
is no longer confined between the conveyor walls 43, for
example, of conveyor 36. The stream thus expands outwardly
and transversely across the screen 41. At the same time,
the screen 41 is driven by a vibrating mechanism for convey-
ing the remainder of the combined stream, still including
glass, plastic and aluminum articles, from the upstream end
42 to the downstream end 44 thereof. The vibrating screen
conveyor is model number VS-60144 manufactured by Griffin &
Company of Louisville, Kentucky, and includes mesh openings
of about 2 inch squares for permitting further residue and
undesirable articles to fall therethrough.
It will be noted that the downstream end 44 of
screen 41 is quite a bit narrower than the upstream end 42
of the vibrating screen conveyor 41. Thus, as the combined
stream moves from the upstream end 42 to the downstream end
44, it is first expanded (from conveyor 36) and then concen-
trated by the tapering guides 45 and 46, at the downstream
end 44, for introduction to the closed air loop separation
station 28, as will be further described.
The vibrating screen apparatus 41 includes a
bottom plate 47. When residue material falls through the
screen, it lands on the plate 47 and is conveyed to a
discharge chute 48, from where it is introduced to a dis-
charge conveyor 49 for transfer to the optional roll-off
2068935
residue container 13. It will be appreciated that the
roll-off residue container 13 is optional and can be elim-
inated. For example, if the stream is guaranteed free of
residue, if residue is otherwise removed, or if residue is
deposited directly on conveyor 40, container 13 will not be
needed. The chute 48, for example, could simply be extended
to deposit residue on the adjacent residue conveyor 40 for
ultimate deposit in the residue roll-off container 17.
From the discharge end 44 of vibrating screen 41,
the commingled stream, still including glass, plastic and
aluminum articles, is introduced to a closed air loop
separation station 28, where the aluminum and plastic
articles are lifted from the glass articles and carried away
by a moving column of air. Thereafter, the glass articles
are conveyed away from station 28 for further sortation and
classification, while the combined stream of plastic and
aluminum articles are also conveyed by the air to a dis-
charge from the closed air loop for further separation.
Perhaps the details of the closed loop air sepa-
ration apparatus are best seen in Figs. 2 and 3. In Fig. 2,it will be appreciated that the commingled stream has been
discharged from conveyor 36, across screen 41 at discharge
end 44 into the station 28.
Station 28 is defined, in part, by a closed loop
air separator 50. Essentially, the combined stream is
conveyed through the station 28 and a closed loop of moving
air, a portion of which defines an upwardly air flow or
column. is directed from beneath the combined stream,
206893S
through it and upwardly to lift off the lighter plastic and
aluminum articles from the glass articles. The combined
plastic and aluminum articles are then entrained in the air
flow and conveyed to a rotary screen separator or a centrif-
ugal classifier where the aluminum and plastic articles aredischarged through an air lock and the air returns to the
blower intake for further upward impingement on the moving
commingled stream, all in a closed loop configuration.
The closed loop separator S0 thus includes a
blower 51, and a duct 52 connected from an exhaust of the
blower to a horizontal duct 53 at a lower end thereof. DUct
s3 extends beneath an inclined, commingled stream receiving
perforated plate 54. Discharge end 44 of screen 41 and
plate 54 are disposed to minimize the drop of the stream to
the plate.
A dust skimmer diagrammatically indicated at 52a
(Fig. 3) is provided for venting a portion of the air to
maintain a negative pressure in the loop and to remove dust
from the air loop.
Air exhausting from the blower is conducted
through the duct 52 to the duct 53 and from there upwardly
through the perforated plate 54 into the tapered or converg-
ing duct 55, defining an upwardly moving air column 56.
Duct 55 is connected to an upper horizontal duct 57, which
is attached to the inlet end 58 of a separator 59. Separa-
tor 59 has an internal exhaust area 60, which is adapted for
connection through duct 60a to blower 51. From the blower
206893~
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outlet the air moves to the inlet end 61 of the duct 52 for
return to station 28.
A rotatable vane air lock 62 is connected to the
lower end 63 of the separator 59. Air lock 62 is generally
s cylindrical in shape, as shown in Fig. 3, and is provided
with a series of rotatable vanes 64.
ROTATING SCREEN SEPARATOR
Separator 59 can be a simple centrifugal separator
(Fig. 3), but preferably a rotating screen separator (such
as shown in the top portion of Fig. 5) is used. Such a
separator includes a rotatably mounted cylindrical screen
59a driven by a slave drive 59s from the rotatable air lock
62a having a plurality of rotatable vanes 64a.
Screen speed is not generally sufficient to throw
off articles held thereon by air. However, as the screen
59a rotates, articles at the 12 o~clock position (Fig. 5)
are hit and wiped off the screen by incoming articles
entrained in the air stream in duct 57. Air e.Yits through
the screen into duct 60a which feeds an input of blower 51,
as noted above.
Alternately, as plastic and aluminum articles are
received in a centrifugal separator 59 (Fig. 3), they engage
the back wall 65 thereof and drop out into the air lock 62.
From there the rotating vanes 64 progressively drop the
combined plastic and aluminum articles through discharge end
66 while maintaining an essentially sealed outlet from the
separator.
2068935
--19--
CLOSED LOOP SEPARATION
Accordingly, it will be appreciated that a closed
loop separator 50 generates and defines a closed loop of
air, and more particularly in at least one portion, an
upwardly moving column of air. That column arises, from
beneath the commingled moving stream of articles, up through
a porous plate supporting such articles, to lift and carry
off lighter aluminum and plastic articles from heavier glass
articles at station 28. The lifted articles are introduced
to a separator 59 for discharge while the air column is
separated from the articles at the separator 59 and is
returned to the blower inlet, providing a closed loop of air
flow.
The blower or some other portion of the closed
loop system includes an adjustable exhaust, and appropriate
dust filter or skimmer s2a, for bleeding off air as de-
scribed above. More particularly, it will be appreciated
that it is desirable to maintain at least a slight negative
pressure within the closed loop system of the closed loop
separator 50. In that regard, it will be appreciated that
the air velocities remain relatively high, while the pres-
sures are kept relatively low in order to provide the
negative pressure differential with respect to the pressure
inside the system and the ambient pressure outside the
system, so as to reduce leakage from inside to outside the
system.
As an example, the velocity of the air impinged on
the commingled stream on the porous surface 54 is approxi-
mately 1800-2300 feet per minute, which is sufficient to
2068g3~
-20-
lift aluminum and plastic articles of the type found in many
recycling systems, such as aluminum cans, plastic bottles
and jugs. The air velocity of approximately 1800-2300 feet
per minute translates to a closed moving air loop, wherein
the air velocities along the loop somewhat differ, for
example, from about 1500 feet per minute at the blower
inlet, to about 2600 feet per minute at the inlet station 28
just beneath the porous plate 54. These ranges provide
sufficient velocity and air flow in the vertical lift
portion of the loop to effectively separate the constituents
anticipated in the stream as described herein. Thus, while
there may be a positive pressure at the fan discharge, the
downstream pressure through the system falls to a negative
pressure with respect to the outside air. The aforemen-
tioned bleed off, for example, may amount to about tenpercent (10%), in conjunction with this operation, providing
the negative internal pressure desired.
More specifically, an air flow of about 18,000 cfm
with a commingled stream contacting velocity of about
1800-2000 fpm is sufficient to separate aluminum and plastic
articles from glass where heavier plastic articles such as
plastic liquid detergent bottles are not contemplated. When
they are included, a flow of about 20,000 cfm at stream
contacting velocities of about 2000-2300 fpm is preferable
So these can be separated as well.
The closed air loop separator 50 differs from that
separator described in U.S. Patent No. 4,915,824 in several
significant respects. First, it will be appreciated that
206`8~35
the duct 55 defining the upwardly moving air column 56 is
much narrower than that of the separator in the noted
patent. In the separator in the noted patent, it will be
appreciated that tobacco particles are projected, by means
of vanes across the chamber within the separator. Varying
air streams are impinged on the projected arc of particles
to lift the lighter particles from the heavier ones. On the
other hand, in the current separator, it will be appreciated
that the commingled stream of glass, aluminum and plastic
articles are discharged from the discharge end 44 of the
vibrating screen onto the porous plate 54, where the arti-
cles slide along that plate to a discharge end 70 thereof.
The remaining articles, primarily of glass at this point,
are discharged onto a conveyor 71, which conveys the remain-
ing glass to the various glass sort stations downstream.Accordingly, the articles to be separated are not projected
across the closed loop, but are conveyed across the closed
loop and the porous plate 54. Like the tobacco separator in
the U.S. patent, the closed loop air flow is divided into a
plurality of air streams, as shown in Fig. 2, by means of
vanes 67 such that a first air stream 68 closer to the
discharge end 44 of the screen 41 is of a faster velocity
impinged across the commingled stream than a more downstream
air stream portion 69 of the column moving upwardly and
nearer the discharge end 70 of screen 54. However, it is
believed that even a homogenious air stream moving upwardly
throuqh the plate 54 could be suitable.
206893~
-22-
Moreover, it will also be appreciated that porous
plate 54 is only slightly inclined in the current invention,
much less than the screen of the patent which is mounted at
a much steeper angle. It is desirable to maintain the glass
articles in the largest possible pieces. Having them slide
down an incline at fast speeds can lead to more break up.
Accordingly, the incline of plate 54 is determined to be
small as reasonably possible to maintain gentle movement of
the moving stream.
GLASS SEPARATION
Turning now to a further description of the glass
separation feature of the system, the glass articles com-
prising all clear (flint), green and amber glass articles
are discharged from the station 28 onto the conveyor 71 and
conveyed to a plurality of manual glass sort stations 72 and
73. At stations 72, 73, individual operators pick up the
various glass articles and direct them into an appropriate
chute as shown in Fig. 1 at a number 74. As shown in Fig.
1, it will be appreciated that the conveyor 71 diverges into
upper and lower (as seen in Fig. 1) conveyors 75 and 76, so
that the combined glass streams can be broken down and
expanded into two streams for efficiency of sorting.
Respective chutes 74 are connected to various conveyors 77,
78 and 79 in a known fashion. Conveyor 77 receives clear
(flint) glass articles from clear glass article chutes and
deposits them onto a glass loading conveyor 80 for deposit
into a clear (flint) glass roll-off 15. Conveyor 78 re-
ceives green glass articles from chutes receiving green
-23- 2~6`8935
glass articles from the operators at stations 72, 73 and
deposits the green glass articles onto a glass load conveyor
81 for conveying green glass articles into the roll-off
container 16. Conveyor 79 receives amber glass articles
from chutes into which amber glass articles are deposited
and conveys amber glass articles to conveyor 82, which
conveys the articles for loading into the amber glass
roll-off container 18. It will be appreciated that each of
the roll-offs 14, 15, 16 and 18, for example, are provided
with diverting chutes or conveyors 84 through 87, as shown
in Fig. 1, for spreading the articles received into the
respective roll-off containers 14, 15, 16 and 18.
PLASTIC AND ALUMINUM SEPARATION
Returning now to station 28, it will be appreci-
ated that aluminum and plastic articles have been lifted at
that station to a separator 59, where they are discharged
through the air lock 62 (or 62a) in a commingled stream of
plastic and aluminum articles into plastic-aluminum sepa-
ration station 32.
In one embodiment (Fig. 3) separation station 32
~0 includes apparatus for first separating larger plastic
articles from the combined stream of plastic and aluminum
and thereafter means for separating the smaller remaining
plastic articles from the aluminum. After the smaller
plastic articles are separated from the aluminum, ~he larger
and smaller plastic articles are recombined for compaction,
optional piercing, and collection, and the aluminum articles
are separately collected.
. 206~935
-24-
The station 32 thus in one embodiment (Fig. 3, 4)
comprises apparatus known colloquially as a "grizzly
scalper" 90, model number GS-3660, manufactured by Griffin &
Company of Louisville, Kentucky. This scalper includes a
vibratory conveyor having, as perhaps best seen in Fig. 4, a
plurality of longitudinal bars 91, which are generally
parallel, but slightly diverge from an upstream end 92 to
the downstream end 93. As the combined aluminum and plastic
are conveyed along these bars by means of vibration of the
conveyor, all smaller aluminum and plastic articles fall
therethrough while the larger plastic articles such as milk
jugs and large beverage containers for example, remain on
top of the bars and are conveyed onto a discharge end 94 and
then transversely to a discharge chute 95.
Meanwhile, the aluminum and smaller plastic
articles which fall through the bars 91, land on an eddy
current non-ferrous metal separator conveyor 96, where they
are conveyed toward a discharge end 97 thereof. The eddy
current non-ferrous metal separator is manufactured by the
Eriez Company of Erie, Pennsylvania, and is known as its
model number ECS-24. This particular separator has means to
repel the aluminum articles. lhus as the combined aluminum
and plastic articles are conveyed toward the discharge end
97, the aluminum articles are cast outwardly as shown, where
they land on a conveyor 98. From conveyor 98, the aluminum
articles are conveyed to conveyor 99, where they are dis-
charged by means of the diverting chute 84 into the aluminum
2~68935
-25-
roll-off container 14, or to an appropriate baler of any
suitable type.
The plastic articles, however, are not repelled by
the non-ferrous metal separator and thus their trajectory is
much shorter and they land on the closer conveyor 100.
Conveyor 100 moves directly under the discharge chute 95 of
the "grizzly scalper" 90, such that the larger plastic
articles moving through the discharge chute 95 are dis-
charged onto the conveyor 100 and are thus recombined with
the smaller plastic articles, where they are conveyed to
conveyor 101, for transfer to a compactor or baler 104 prior
to discharge or loading into roll-off container 19. Any
suitable compactor or baler such as baler model number
HAL-7RP made by the Selco Baler Company, division of Harris
Group of Baxley, Georgia. Optionally, the plastic articles
can be first introduced to a plastic perforator 102, and
from there to a compactor or baler 104. The plastic
perforator 102 serves to punch holes in the various plastic
articles so as to facilitate their compaction by releasing
~0 air, etc. which might be otherwise trapped therein.
ALTERNATIVE PLASTIC AND ALUMINUM SEPARATION
In another embodiment, as shown in Figs. 5 and 6,
a "trommel" 110 is used to separate plastic from aluminum
articles and discharge them respectively onto conveyors 98
(aluminum) and 100 (plastic). Such a trommel is effectively
used in situations where the plastic and aluminum introduced
to the trommel 110 include aluminum cans, many of which may
have been pre-crushed, and larger ~lastic items such as
206893~
-26-
various forms of liquid containers. In many recycling
programs the nature of the aluminum and plastic constituents
can be predetermined to render this separating embodiment
particularly ef f icient.
In this regard, trommel llO inclines a cylindrical
drum 111 mounted for rotation about a declining axis lllx
An inlet chute 112 is positioned to receive plastic and
aluminum articles from separator air lock 62 or 62a and
deliver them to the internal area bounded by drum 111.
Openings 113 in the drum surface are sized to pass the
smaller aluminum axticles, but not the larger plastic
articles.
As drum 111 rotates, the aluminum articles move
along the drum and fall through openings 113 onto chute 114
having a discharge outlet 115 laterally spaced from beneath
the drum 111 and over aluminum conveyor 98. Another chute
116 is disposed to receive larger plastic articles, dis-
charged from lower end 117 of drum 111, and to discharge the
plastic onto plastic conveyor lOO.
In this manner, plastic and aluminum are lifted
from the stream at station 28 and separated at station 32 by
means of a trommel llO. As noted, this embodiment is
particularly useful when the aluminum and plastic constitu-
ency of the stream can be predetermined with consistency and
where the size of the aluminum articles and the size of the
plastic articles lend themselves to efficient separation by
this means.
-27- 2068935
of course, as diagrammatically shown in Figs. 5
and 6, the drum 111 can be mounted to ride on motor driven
rollers 118 for rotation, or can be constructed or mounted
in any suitable fashion.
GENERAL OPERATION
In one example of operation a commingled stream of
ferrous glass, plastic and aluminum articles are deposited
onto the receiving conveyor ll and thereafter transferred by
conveyor 21 into the system. Where the separator station 28
lo is approximately 3-4 feet wide and the air flows are as
previously mentioned, such a system can be utilized to
handle on the order of 10 to lS tons per hour of commingled
stream articles with the ferrous glass, plastic and aluminum
articles all being separated in kind from each other by
means of the apparatus at a very efficient flow rate.
Moreover, utilization of the apparatus as de-
scribed provides very efficient article separation, with a
minimization of other kind articles ending up in the respec-
tive collection points or roll-offs. Moreover, it will be
appreciated that the closed loop separator 50 greatly
facilitates the separation of aluminum and plastic articles,
on the one hand, from glass articles on the other, without
subjecting the glass articles to undue handling or breakage.
In this regard, the discharge end 44 of the vibratory screen
conveyor is located as closely as possible to porous plate
54, the discharge end 70 from the station 28 is oriented to
make as gentle a transition as possible onto the conveyor
71, and plate 54 is inclined at only a minimum angle to
206893~
-28-
assure gentle article stream flow. In the meantime, the air
flows and velocities are sufficient to lift the aluminum and
plastic articles upwardly in upwardly moving air columns.
It will be appreciated that various portions of
the system lO could be eliminated or modified as suggested
herein dep~nding, for example, on the nature and content of
the commingled stream of articles. For example, if residue
articles and materials are eliminated, the initial manual
sorters or operators are not necessary. Where certain
plastic and aluminum constituents are predicted, the trommel
separator described can be used in place of the "scalper"
apparatus described.
It will also be appreciated the other variations
of the invention could be used. For example, the air
chamber or flow station 28 could be separated into two or
more chambers and respective various stream constituents
lifted and separated from each other by varying air veloc-
ities of separate closed air loop portions in each respec-
tive chamber. Such a variation may render further down-
stream separation of the lifted constituents unnecessary.
ALTERNATIVE SYSTEM LAYOUT
Moreover, other system layouts embodying thefeatures described above, or modifications thereof can be
used.
For example, Fig. 7 diagrammatically illustrates
an efficient layout utilizing the foregoing principles.
~his system is also for handling a commingled stream as
noted above and utilizes a manual sort station 22, a ferrous
206893~
removal station 24, a screening station 26, an alumi-
num/plastic lift or sort station 28, manual glass sort
stations 30, and plastic and aluminum separation stations 32
functionally and essentially like those described above.
These stations are numbered like those in Figs. 1-6 since
similar sortation or separation functions are performed at
each.
The layout in Fig. 7 illustrates very efficient
flow paths, and to accommodate these, certain orientation
changes have been made in the apparatus to accommodate the
different flow paths.
Incoming commingled articles are conveyed in a
commingled stream on a pit conveyor ll to incline conveyor
21a, and onto belt conveyor 36a at residue presort station
22. Thereafter, an overhead magnetic belt 2sa~ like that
described above, is used to remove ferrous containing
material into bin 12a at station 24.
At station 24, the remaining commingled stream is
turned 9O degrees onto screen 41a of screening station 26
which has a discharge 44a to a residue bin 13a. At the end
of the screen 41a the stream is deflected again 9O degrees
and introduced to the aluminum/plastic lift or sort station
28, which forms part of a closed loop air separation appara-
tus essentially like that described above. In this embodi-
ment, however, the duct work defining the closed loop isextended, as will be described, to accommodate the somewhat
different orientation of the entire system. It essentially
2068935
-30-
functions, however, in the same manner as in the previously
described apparatus.
Turning now to the combined remaining glass
articles not lifted upwardly at station 28, this glass is
discharged onto a sort conveyor 71a, where it is manually
sorted at station 30 into respective bins 15a, 16a and 18a
as indicated. Mixed and broken glass is sorted into a
mixed/broken bin as indicated.
From station 28, aluminum and plastic articles are
lifted upwardly in a duct (not shown but corresponding to
duct 55) forming a part of the closed loop air separation
apparatus and are then conveyed horizontally in another duct
(not shown but corresponding to duct 57) to a separator like
that of the centrifugal or rotating separator shown in Fig.
3. This duct is disposed above conveyor 71a as shown in
Fig. 7. The aluminum and plastic are then discharged from
this separator to a grizzly scalper 90a (similar to scalper
9o). This scalper discharges plastic articles onto a
plastic conveyor 100a from where these articles can be
sorted into a P.E.T. plastic bin and an H.D.P.E. plastic bin
as illustrated.
Meanwhile, an eddy current non-ferrous metal
separator conveyor apparatus s6a (like that of separator 96
of Fig. 3) is operable to discharge aluminum articles into a
chute 120 for discharge into the aluminum bin as shown.
In the meantime, the closed loop air flow, sep-
arated from the plastic and aluminum articles, is returned
to the general area of station 28 by an elongated duct (not
2~6893~
-31-
shown but corresponding in function to duct 60a) to a fan
input (not shown). This fan has an output connected via
ducts (not shown but corresponding in function to ducts 61,
52) to station 28 to blow upwardly and lift aluminum and
plastic articles from the commingled stream, all as noted
above, in a closed loop system. Accordingly, this alterna-
tive layout envisions a different disposition of the compo-
nents described previously in this application, with extend-
ed duct work utilized to provide efficient flow paths and
efficient component location.
Of course, flow rates and pressures in the closed
loop described are controlled to provide the separation,
conveying, dust skimming,and article flow rates and
functions desired, such as described with respect to the
apparatus of Figs. 1-6. Very efficient through puts,
together with an efficient usage of facility floor space are
thus provided.
IMPROVED AIR SEPARATOR
A preferred embodiment of the improved air separa-
tor is illustrated at 130 in Fig. 8. It will be appreciatedthat this separator may be utilized, for example, in place
of the separator 59 as shown in Fig. 2, and is operable for
receiving the fast-moving aluminum and plastic articles
which have been lifted in the air column of the closed loop
air stream, away from glass and heavier articles on the
plate 54 at station 28.
The separator 130 is particularly useful where the
commingled air stream, in addition to the articles noted
206893~
-32-
above, originally includes other extraneous and relatively
lightweight articles of paper and plastic, for example.
Such extraneous articles might include paper labels, for
example, and such plastic articles might include, for
example, lightweight plastic bags or films. All these can
be entrained in the air stream and may agglomerate on the
screens of the previously described two separators 59.
These articles are difficult to remove therefrom, and clog
the screen, reducing its efficiency. Where such commingled
streams include a relatively large percentage of lightweight
paper, plastic or other foreign objects which have not been
previously removed, it is thus desirable to increase the
efficiency of the flow through of the entire system. The
separator 130 is particularly useful in that regard when
compared, for example, to the separators 59, disclosed
above.
Accordingly, it will be appreciated that the
separator 130 is utilized in the closed loop downstream of
the aluminum and plastic sort station 28 for separating
aluminum and plastic articles lifted from the glass at
station 28 from the closed loop air stream, and also for
separating any lighter materials which have been entrained
in that air stream. The separator in particular is connect-
ed to the upper end of the duct ssa, which converges from
station 28 and defines an upwardly moving stream 56a of air
conveying plastic and aluminum articles therein.
As shown in Fig. 8, the separator 130 is opera-
tively connected to the stream s6a via the conduit 131 and
206~93~
-33-
includes an inlet conduit or duct 132, having an upstream
end 133 and a downstream or discharge end opening at 134 as
shown in Fig. 8 into an enlarged chamber 135.
Chamber 135 includes tapering walls, such as at
s 136 and 137, which converge towards an outlet 138, opera-
tively connected to an air lock 62a, which is identical to
the air lock 62 previously described in this application.
Chamber 135 may have relatively planar walls, tapering as
shown in Fig. 8, or it may be of circular configuration,
terminating in a cone, opening downwardly into the air lock
62a. Also, it will be appreciated that chamber 135 has a
cross-section larger than effective duct opening 134.
An enlarged exhaust duct 140 communicates with
chamber 135 at exit opening 141 and upper portion 142 of the
exhaust duct tapers to a duct 143, of lesser diameter than
the exhaust duct 140 and the tapered portion 142. Duct 143
has a discharge end 144, feeding into the vertical housing
145.
Vertical housing 145 extends downwardly to a
receptacle 146. Housing 145 may comprise a rectangular or
circular duct provided with an air lock section 147, defined
by an upper door 148 and a lower door 149. Housing 145 also
has an outlet opening 150 connected to a conduit 151, which
functions similarly to conduit 60a of Fig. 2. That is to
say that conduit 151 leads from the housing 14S back to the
inlet of a fan or blower 51.
A porous air separation conveyor 155 comprises
over two vertical runs, 156 and 157, deferred by means of
2068~35
-34- -
horizontally disposed pulleys 158 and 159, serving as head
and tail stock for the conveyor 155. Pulleys or head stocks
158 and 159 are mounted on horiæontal axes and are of such a
width to extend substantially across the width of the
housing 145. A porous belting material, such as
a perforated or woven fabric belt or metal belt made with
perforated slats, is formed in an endless loop about the
pulleys 158 and 159, such that it is disposed in the
downwardly extending run 156 and the upwardly moving or
return run 157. This conveyor functions as a screening
conveyor for the air stream as it moves away from the
chamber 135 and through the ducts 142, 143 and across
housing 145, on its way back to the inlet of the blower or
fan.
The operation of this separator will now be
described. It will be appreciated from Fig. 8 that separa-
tor 130 is disposed so as to receive the column 56a of air,
entraining along with it plastic and aluminum articles which
have been lifted upwardly from station 28 from any glass and
any heavier articles at station 28. The lifted aluminum and
plastic stream 56a might also include lighter materials such
as paper, plastic film, plastic bags, etc., which are also
lifted by the fast-moving air stream. As shown in Fig. 8,
the fast-moving air stream is confined in the column or
conduit 55a, which is a portion of the closed loop sepa-
ration stream described previously in this application. The
air stream moves through the curved duct 131 at a high rate
of speed, which may be as high, in this particular
2~6893~
application and for example, as 4S00 feet per minute. When
the stream moves through the duct 131, it enters the up-
stream end of the duct 132 and moves through duct 132 into
the chamber 135.
It should be appreciated that the duct 132 has a
rear wall 139, against which the stream is directed.
Materials in the stream will tend to engage this wall and
then flow or move downwardly into the chamber 13S.
Since the chamber 13S is of a substantial volume
and cross-sectional area, as compared with the volume and
cross-sectional area of the ducts 131 and 132, for example,
the velocity of the air stream is significantly reduced as
it enters the chamber 13S such that air exiting from the
chamber 13S through the opening 141 into the exhaust ducts
140 and 142 may be reduced to, for example, as low as 800
fpm in velocity. The aluminum and plastic as indicated by
the arrow so marked in Fig. 8 tends to fall out of this air
stream and is guided by the cone of the chamber 13S or the
tapered walls 136, 137, toward the opening 138 and into the
air lock 62a. The aluminum and plastic is thus handled by
the air lock for further separation, as described previously
in this application.
The air stream, at this point of relatively low
velocity, now moves upwardly through the ducts 1~0 and 142
to the concentrated duct 143, where the velocity is again
increased and may be on the order of approximately lS00 to
2000 fpm~ The duct 143 directs the flowing air stream at
this now increased velocity to the exhaust end 144, where
2068935
- 36 -
the air stream is directed into the housing 145 and toward
the porous conveyor 155. When the air stream hits the
conveyor, the air tends to move through the porous material
of the conveyor belting, through the housing 145, and
through the opening 150, to the conduit 51, from where the
air stream is returned to the blower 51, where recirculation
as part of the closed loop separation system.
Porous conveyor 155 is operable to remove from the
air stream, lighter weight materials which may not have
fallen out of the air stream in the chamber 135. These may
include, for example, paper articles or lightweight plastic
articles such as plastic film, labels, plastic bags, etc.
These articles engage the porous belting in the downwardly
moving run 156 of the conveyor 155, where they are conveyed
downwardly toward the lower end 161 of housing 145. Since
the lower end 161 of housing 145 is shut off by door 148,
there is relatively no air movement in the lower end 161 and
articles reaching the end of the conveying run 156 will tend
to fall off the conveyor into the lower end 161 of the
housing 145. To this end, the pulley 159 may be a solid
pulley, so that there is relatively no air flowing through
the porous conveyor web at that point, to facilitate the
dropping off of lightweight articles therefrom.
In addition, a scraper 162 may be positioned
within the housing 145 on the upwardly moving or return run
157 of the conveyor. Scraper 162 may have one or more
flexible rubber strips 163, for example, disposed in sliding
engagement with the conveyor run 157, for scraping off any
2068935
-37-
material which still resides thereon. As well, scraper 162
forms an obstruction to prevent any material from moving
upwardly in the housing 145 to the opening 150 and duct 151
Since the conveyor 155 extends across the housing and since
the upper tail stock 158 is located very near a housing
wall, the undesired materials of lighter weight which are
entrained in the air stream at this point, are removed from
the air stream, and are obstructed from access to opening
150.
Once the materials have fallen into the lower end
161 of the housing 145, they fall onto the sliding door 148
This door may be selectively opened by sliding transversely
to permit materials in the duct or lower end 161 of the
housing 145 to fall beneath the door 148. Thereafter, the
door 148 can be closed and the door 149 slid open to permit
the materials in the air lock section 147 to fall into the
receptacle 146.
Accordingly, the separator 130 provides an advan-
tageous means by which materials are purged from the closed
loop air stream, which is then returned to the fan for
reintroduction to the station 28 at high velocity to lift
still further plastic and aluminum articles from glass and
heavier articles at the station 28. The aluminum and
plastic articles so lifted are deposited via chamber 135 to
air lock 62a, from where they are further separated as
previously disclosed in this application. The remaining
lighter weight materials which do not drop out of the air
stream within chamber 135, are effectively removed by the
2068935
-38-
conveyor 155 and deposited in the receptacle 1~6. Since the
conveyor 155 has a lower end disposed in a housing where
there is relatively little, if any, air movement, lighter
weight materials collected on the conveyor 155 are prone to
fall off and are thus efficiently separated from the air
stream.
ALTERNATIVE EMBODIMENTS OF AIR SEPARATOR
Figs. 9-11 illustratively disclose alternative
embodiments of the separator of Fig. 8. Turning first to
lC Fig. 9, separator 170 includes an inlet duct 171, having a
discharge end opening 172, through which an air stream
entraining aluminum and plastic articles lifted from a
separation station 28 (not shown), are conveyed at high
velocity by means of a closed loop portion of an air stream
into an enlarged chamber 173. Chamber 173 is of larger
cross-sectional area than the duct opening 172. A sepa-
ration conveyor 174 is disposed horizontally about head
stock and tail stock 175, 176, conveyor 174 having an
upstream run 177 moving in the direction as shown by the
arrow A in Fig. 9, and a downstream or return run 178 moving
in the direction of the arrow B as shown in Fig. 9. The
conveyor 174 is disposed in a cross exhaust duct 179, so as
to form a closure across the mouth 180 of the duct 179. A
seal (not shown) can be used at the right hand end of the
conveyor to positively seal off duct 179 and insure all air
flowing into it goes through the conveyor. Duct 179 is
operatively connected to the blower 51 for closing the
closed loop air stream and for directing the purged air
206893~
-39-
stream into the blower inlet and thence into the station 28
for separation purposes.
The conveyor 174 includes a porous conveyor web as
described with respect to the conveyor 155 in Fig. 8. An
opening 181 is disposed in the duct 179 on the upstream side
of the conveyor 174 and an enlarged chamber 182 is disposed
on the other side of the opening for receiving paper and
scrap material from the conveyor 174. Chamber 182 leads to
a depending conduit 183 for receiving paper, plastic or
other scrap materials onto sliding door 184 which, together
with door 185, defines an air lock 186 for the removal of
paper and plastic materials into receptacle 187, in the same
fashion as described with respect to the apparatus of Fig.
8.
It will be appreciated as the high velocity stream
56a is admitted into the chamber 173 through the opening
172, the greater cross-sectional area of the chamber causes
a pressure drop and substantially reduces the velocity of
the air flow. Some of the air flow and articles engage back
wali 188. Since the velocity of the air stream is substan-
tially reduced, plastic and aluminum articles can fall out
to the air lock 62a, while the air stream then moves upward-
ly through the porous conveyor 174 and into duct 179. Any
lighter weight material such as paper or plastic, for
example, which are still entrained in the moving air stream,
engage the conveyor 17~ and are conveyed to the left, or in
the direction of arrow A. Once these materials pass the
opening 181, they reside within the chamber 1i32, in which
2068935
-40--
there is relatively no air flow due to the increased chamber
size and the fact it has no open flow outlet. The materials
thus drop off the conveyor 174 and into the chamber 182 for
collection in receptacle 187. A scraper 189, like scraper
162, may be provided, as shown in Fig. 9, for the purpose of
finally scraping off from the conveyor 174 any material
remaining thereon.
Another alternative embodiment is disclosed in
Fig. 10. In this particular embodiment, a separator 195
comprises an entry duct 196, having a duct opening 197, into
an enlarged chamber 198, having tapering or conical walls
converging to a discharge opening 199 into an air lock 62a.
The chamber 198 is of larger cross-sectional area than duct
opening 197, such that the moving column of air, plastic and
aluminum materials entering the chamber experience a pres-
sure drop and reduce in velocity to permit the aluminum and
plastic materials to fall out to the air lock 62a. The air
them moves upwardly through the tapering portion 200 to the
duct 201, where it is conveyed to or toward the separation
conveyor 202. Separation conveyor 202 comprises head stock
203 and tail stock 204, about which is wrapped a porous
conveying web or belt into run 205 and return run 206.
Conveyor 202 is disposed across an inlet openinq 207 of duct
208, so that duct 208 is closed off with the exception of
air moving through the conveyor 202. A seal (not shown) may
be provided between the conveyor end and duct wall.
The conveyor extends vertically and downwardly
into a chamber 209, in which there is relatively little
20l~89~
-41-
moving air flow and which is preceded by a diverging chamber
210. At diverging chamber 210, the air stream loses further
velocity from that velocity it had in duct 201 and moves
onto the conveyor 202 and thereafter into the duct 208. Any
lighter weight materials still entrained in the air stream
at this point engage the run 205 of the conveyor 202 and
move downwardly as viewed in Fig. 10, into the duct or
chamber 209, where there is relatively little air flow.
Duct 209 is provided with a lower end 211 and sliding doors
212, 213, which form an air lock 214, for disposal of the
materials removed from the air stream, into the receptacle
215, as described in connection with the preceding embodi-
ments.
Accordingly, it will be appreciatéd that aluminum
and plastic articles are removed from the air stream 56a by
virtue of the reduced air stream velocity, which is generat-
ed by the entry of the air stream into the enlarged chamber
198. From there, the air stream is again concentrated in
the tapering duct 200 into duct 201, from where the air
stream is conveyed to duct 208, which leads to the inlet of
a blower 51. The air stream, however, must pass through the
porous conveyor 202 and any material still entrained in the
air stream, such as paper, plastic film, bags or the like,
engage the conveyor 202 and are dropped out into the chamber
211 for collection in receptacle 215.
Turning now to Fig. 11, a further alternative
embodiment is disclosed, where separator 220 is shown.
Separator 220 is operatively connected to separation station
206893~
-42-
28 via an inlet duct 221, having a discharge opening or duct
222. The separator 220 includes an enlarged chamber 223,
formed by tapering or conical walls 224, 225, converging to
a discharge opening 226. Chamber 220 further has an outlet
opening 227, leading into a duct 228, which is connected to
the inlet of a blower 51 (not shown). The discharge outlet
226 is operatively connected to an air lock 62a, as previ-
ously described in this application. Chamber 223 is larger
in cross-section than duct opening 222.
In this particular embodiment, it will be appreci-
ated that a porous conveyor is not utilized. Instead, a
high velocity column 56a of air entraining therein plastic
and aluminum lifted off of glass and heavier articles at
station 28, is introduced through the opening 222 into the
enlarged chamber 223. By virtue of the enlargement of
chamber 223, the air stream undergoes a pressure drop which
significantly decreases the velocity of the air stream and
entrained articles and permits materials entrained therein
to drop out through opening 226 to the air lock 62a, from
where they can be removed from the air stream and further
separated.
This particular embodiment, as shown in Fig. 11,
is particularly useful where there is a relatively minimal
amount of residual lightweight articles expected in the
commingled stream which is handled in the entire separation
system. In this regard, such prepared commingled streams
may not embody any lightweight paper or plas~ic bags or the
like, ~hich require a particular porous-like conveyor or
- 2 0 6 8 9 3 ~
-43-
some sort of other mechanical screen across the air stream.
Accordinqly, it has been found that in some systems, and
depending on the nature of the commingled stream to be
separated, it is only necessary to provide an air separator
for dropping out the relatively lightweight aluminum and
plastic articles from the commingled air stream, and that
without further screening, the air stream may be then
returned to the inlet of the blower 51 in the closed loop
system.
In each embodiment illustrated in Figs. 8-11, it
will be appreciated that the respective enlarged chamber
135, 173, 198 and 223 are of larger cross-section than the
effective duct openings feeding into them so the velocity of
the closed loop air stream flowing into them is reduced.
Each chamber has an air exhaust outlet or duct, preferably
of smaller cross-section than the chamber to reconcentrate
the air stream and forming an exhaust passage for the
stream. In the embodiments of Figs. 8, 9 and lo, the
exhaust passages are directed onto the porous conveyors
noted for transporting remaining articles thereon away from
the closed loop air stream, thus purging it with a continu-
ously fresh, unobstructed effective screen surface.
In the embodiments of Figs. 8 and lo, the exhaust
passage has a horizontally oriented portion where the
conveyor belt is vertically oriented. In the Fig. 9 embodi-
ment, the exhaust passage is vertically oriented and the
conveyor belt is horizontally oriented.
206893~
-44-
In the Fig. 8, 9 and lO embodiments, the end of
the conveyor extends into a closed or substantially still
air chamber which is generally free of any significant air
flow, to the extend that articles are free to drop from the
conveyor toward the discharging housing between the air lock
doors without being blown back into the air stream or held
on the conveyor by a pressure differential. Also, it will
be appreciated in these embodiments that the respective
exhaust passages are open to the closed chambers upstream of
the conveyor so the articles can be transferred into the
chambers for collection.
Moreover, and as elsewhere noted, the conveyors
can be sealed at one or both ends of the walls of the
passages or housings as suggested by the drawings, or are
otherwise spaced closely enough thereto so articles do not
flow past the screening area and back to the inlet of the
blower 51.
It will also be appreciated that the moving
conveyor screen of embodiments in Figs. 8-lO can be a porous
web belt conveyor as shown or any other type of moving
screen or pourous surface, having a portion in the exhaust
passage and a portion spaced away therefrom, so the screen
moves through the exhaust passage to collect articles and
then away therefrom to discharge the articles from the
screen away from the air straem.
Finally, it will be appreciated that the air locks
associated with the closed chambers of the embodiments of
Figs. 8-lO comprise discharge housings or chambers connected
2~6893~
-45-
to outlets from the closed chambers by means of first or
upper doors, and further include lower doors for opening the
discharge chambers when the upper doors are closed for
collection of the purged articles.
Accordingly, it will be appreciated that the
various embodiments shown in Figs. 8-11 can be utilized in a
separation system as described above for the separation of
aluminum and plastic articles and other articles from the
closed loop air stream, which is utilized to separate
relatively lightweight plastic and aluminum articles from
glass and other heavier articles at a separation station 28,
for example, as described above. The flow through and
efficiency of the embodiments shown in Figs. 8-11 is partic-
ularly desirable and helpful where extraneous lightweight
materials which must be separated from the air stream, are
expected in a commingled stream, such as with the embodi-
ments of Figs. 8, 9 and 10 or where relatively little
extraneous material is expected, wherein the embodiment
shown in Fig. 11 can be effectively utilized. In any case,
the embodiment shown in Fig. 11 will eliminate t~e various
screens shown in all of the figures, where the embodiments
of 8, 9 and 10 serve more efficiently to purge the air
stream of very lightweight materials such as paper and
plastic film and the like, without clogging any screens and
requiring cleaning or downtime.
These and other modifications and advantages will
become readily apparent to those of ordinary skill in the
art without departing from the scope of the invention and
applicant intends to be bound only by the claims appended
heretO.
