Note: Descriptions are shown in the official language in which they were submitted.
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SYSTEM FOR RECOVERY OF SALVAGEABLE
FERROUS AND NON-FERROUS METAL
CO~PONENTS FROM INCIN RATED WASTE MATE~IALS
FIELD OF THE INVENTION
The present invention relates in general ~o a system and
method for recovery of salvageable materials from refuse, and
specifically to a system and method for the recovery of ferrous
and non-ferrous metal components from incinerated waste mateLials.
The present invention further relates to a crusher for selectively
comminuting friable material without comminuting associa~ed
malleable material.
BACKGROUND OF THE INVENTION
In recent years, there has been a dramatic increase in
the volume and variety of solid waste products requiring disposal
by both the private and public sectors. Such solid waste products
have in the past been burned in open incinerators. However, due
to current regulatory and environmental laws and regulations,
incineration of solid waste has been restricted to a significant
extent in many geographic areas and in fact is prohibited in many
urban areas today.
Disposal of solid waste products in sanitacy landfills is
a frequently used alternative disposal method. However, many
existing landfills are reaching their capacity and additional
replacement clean landfills have not been approved by local
regulatory agencies and authorities due to existing environmental
laws and regulations and due to an actual shortage of land in some
geographic areas.
Recover of salvageable and recycleable materials, of
course, reduces the amount of waste products that must be
disposed. Apparatus and methods for recovery of salvageable and
recycleable components, such as glass, plastics, non-ferrous, and
PAT 10377-1
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ferrous materials, from solid waste products are known in the
prior art, e.g., u.5. Patent Nos. 3,549,092: 3,659,396; 3,788,56~;
3,790,091; 3,973,736: 4,020,992; 4,070,278; 4,083,774; 4,337,900;
4,362,276: and 4,387,019. Such recovery apparatus and methods are
used in the recovery of solid waste products prior to disposal of
the solid waste products. However, ferrous and non-ferrous metal
components are generally not ful]y recovered by such prior art
apparatus and methods and carryover with the by-products from the
incineration of the solid waste products.
In addition, the quality of the recovered ferrous and
non-ferrous products varies widely due to the incinerated waste
product carryover, the extreme variability of the moisture content
in both the waste material and ~he residue ash, and the fused
aggregate of carbonaceous incinerated by-products.
A need thus exists for a system that will permit economic
recovery of ferrous and non-ferrous metal, such as aluminum,
components from friable, incinerated waste materials including
carbonaceous incineration by-products, such as ash, and associa~ed
ferrous and non-ferrous metal components. Such a system will not
only permit the recovery of the salvageable ferrous and
non-ferrous metal components from the incinerated waste materials,
but also will reduce the amount of the incineration by-product,
e.g., ash, that must be disposed by conventional disposal such as
landfill.
The present invention pertains to a system for recovering
salvageable ferrous and non-ferrous materials from incinera~ed
waste materials including friable, carbonaceous incineration by-
products such as ash, and associated ferrous metal and aluminum
and other non-ferrous metal components comprising first crushing
means for selectively comminuting carbonaceous incineration by-
products without comminuting associated ferrous and non-ferrous
metal components; first separating means coacting with said first
crushing means for selectively separating comminuted carbonaceous
incineration by-products from ferrous and non-ferrous metal
components: and first magnetic means for separating ferrous me~al
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components from non-ferrous metal components. In a preferred
embodiment, the system further comprises first conveying means for
conveying incinerated waste materials to the first selective
cru~hing means and collection stations for collecting separated
comminuted carbonaceous incineration by-products, ferrous metal
components and non-ferrous metal componen~s. In a more preferred
embodiment, the system further comprises second crushing means for
further selectively comminuting carbonaceous incineration
by-products without comminuting associated ferrous and non-ferrous
metal components; second separating means coacting with the second
crushing means for selectively separating additional comminuted
carbonaceous incineration by-products from ferrous and non-ferrous
metal components; second conveying means for conveying comminuted
carbonaceous incineration by-products and ferrous and non-ferrous
metal components to the second separating means; third conveying
means for conveying ferrous and non-ferrous metal components to
said first magnetic means; and second magnetic means for
separating ferrous metal components from non-~errous metal
components prior to said first crushing means.
In an even more preferred embodiment, the system further
comprises third separating means prior to said first crushing
means to separate noncarbonaceous materials other than ferrous and
non-ferrous metal components, such as glass, sand and dirt, from
the incinerated waste materials and fourth conveying means for
conveying unseparated carbonaceous incineration by-products and
ferrous and non-ferrous metal components from the f irst separa~in~
means to ~he second selective crushing means.
The present invention furthec relates to a method ~or
recovery of ferrous and non-ferrous metal components from
incinerated waste materials using the system of the eresent
invention and to a novel crusher for selectively comminuting
fciable materials without comminuting associated malleable
materials.
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a process schematic diagram of a pref~rred
embodiment of the recovery system of the present invention.
Figure 2 is a plan view of an embodiment of a preferred
selective crusher employed in the ~resent invention.
Figure 3 is a cross-sectional view ~aken through line A-A
of the preferred selective crusher of Figure 2.
DETAILED DESCRIPTION OF THE INVENTION
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The present invention is directed to a system for
recovering salvageable ferrous and non-ferrous mateeials from
incinerated waste materials including friable carbonaceous
incineration by-products such as ash, and associated ferrous metal
and aluminum and other non-ferrous metal components comerising
first crushing means for selectively comminuting carbonaceous
incineration by-products without comminuting associated ferrous
and non-ferrous metal components; first separating means coacting
with said first crushing means for separating comminuted
carbonaceous incineration by-eroducts from ferrous and non-ferrous
metal components: and first magnetic means for separating ferrous
metal componen~s from non-ferrous metal components.
The feed material processed in the recovery system
generally consists of the bottoms or ash material remaining after
incinera~ion of waste materials, and preferably the bottoms or ash
produced in a furnace in a mass burning operation used to generate
electricity. The bottoms product generally includes incinerated
carbonaceous by-products, such as ash, and associated incinera~ed
ferrous and non-ferrous metal components such as aluminum, copper,
nickel and brass. The bottoms product may also include glass and
other refuse typically contained in municipal refuse that are not
completely incinerated at the temperature maintained in the
furnace. Al~hough incinerated waste materials are the preferred
feed stock of the inven~ion, other feed materials, including ash
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and ~sh-related products and non-ferrous and/or fe~rous me~al
components, are also suitable.
ReferLing to Figure l, the feed material is delivered to
a first crushing means 4 in the recovery system of the invention
preferably by a first conveying means 3. The fiest conveying
means 3 may be a belt-type conveyor at an angle from the
hori~ontal, i.e., troughing angle, of between preferably about lO
and 45 degrees. The system preferably includes a second conveying
means 5 that conveys the comminuted carbonaceous incineration by-
products and ferrous and non-ferrous metal components from the
first crushing ~eans 4 to a first separating means 6. The second
conveying means 5 may again be a belt-type conveyor or any oeher
conventional conveyor similar to the first conveying means 3. The
first separating means 6 which separates comminuted carbonaceous
incineration by-products from ferrous and non-ferrous metal
components may be any conventional separator, such as a screen
separator, which will separate comminuted carbonaceous by-products
from the associated ferrous and non-ferrous metal components.
Preferably, the second conveying means 5 and first separating
means 6 is a combination vibrating screen~conveyor such as sold by
Bonded Scale and Machine Co. Most preferably, a variable angle
vibrating conveyor/screen separator is used in order to regulate
the variable flow of the comminuted carbonaceous by-products and
associated ferrous and non-ferrous metal components across the
screen/conveyor to enhance separation. The screen angle is
preferably between about lO and 45 degrees, and most preferably
between about 13 and 20 degrees, from the horizontal, with the
exact angle being selected to maximize the reten~ion time of the
material on the screen without overload;ng the screen. The
vibrating screen/conveyor has a plurality of openings, preferably
between 3/8 inch and l l/2 inches, and most preferably about
3/4 inch, in diameter, through which a portion of the vibrated ash
or other carbonaceous incineration by-product prefeLably less than
about 3/4 inch to l inch in diameter passes to a collection
station positioned below the vibrating screen/conveyor. The
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collection station 12 may be any conv~ntional collector apparatus
but preferably is a belt conveyor or another collection device
which transports the ash or other carbonaceous incineration
by-product to a further collection station from which it is
transported to a landfill for disposal.
The first crushing means 4 is a unique crusher which
selectively comminutes friable carbonaceous incineration by-
products to a desired particle size without comminuting associated
ferrous OI non-ferrous metal components. The crusher is
preferably a single rotating roll-type crusher 20, such as shown
in Figures 2 and 3, having two to six, preerably four, tungsten
carbide welds 30 e~uidistant-spaced longitudinally across the
exterior surface of a rotating roll 32 to comminute the
carbonaceous incineration by-products. In juxtaposition to the
roll is a generally stationary backing plate 34. The incinerated
waste materials are conveyed to the single eotating roll-type
crusher 20 where they are delivered ~o the rotating roll 32. The
rotating roll 32 is set a sufficient distance from the backing
plate 34 to comminute the carbonaceous incineration by-products to
a diameter of preferably between about 3/8 to l l/2 inches or
less, and most preferably l inch or less, without comminuting
associated ferrous and non-ferrous metal components. The backing
plate 34 is maintained in place by coil springs, air pressure
cylinders, hydLaulic cylinders or other means which serves as a
release device, compressing when ferrous or non-ferrous metal
eomponents in the incinerated waste materials enter the space
between the rotating roll and the baeking plate at a pressure
suffieient to comminute the carbonaceous incineration by-products,
but insufficient to comminute the associated ferrous and
non-ferrous metal components. In a most preferred embodiment, the
backing plate 34 is maintained in place by two spaced-apart air-
pressure controlled rams 36 attached to the base of the backing
plate 34. The rams are maintained under an air pressure of
preferably 40 + lO psi and release and return to place almost
instantly when a ferrous or non-ferrous metallic component enters
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the space between the rotating rol] and the backing elate and is
passed. The ability to vary the air pressllre is desirable in
order to be able to comminute the ~arious carbonaceous
incineration by-eroducts encounteLed from the same or different
incineration processes.
The ferrous and non-ferrous metal components are
separated in the claimed system by first magne~ic means ll. The
first magnetic means ll may be used in the system prior or
subsequent to the first crushing means 4. Pre~erably, the first
magnetic means ll is used in ~he system subsequent to the first
crushing means 4. The first magnetic means ll may be any type of
magnet which will separate the ferrous metal components, such as
iron and steel components, from the non-ferrous metal components,
such as aluminum. In a preferred embodiment of the invention, the
magnet is a magnetic drum head pulley, such as manufactured by
Sterns Magnetics, Inc. or Erie Magnetic, Inc. The ferrous metal
components are released from the magnet, and the ferrous and
non-ferrous metal components are deposited at one or more
collection stations lZ. Preferably, the ferrous metal components
are deposited at one collection station and the non-ferrous metal
components are deposited at another collection station. The
salvaged ferrous and non-ferrous metal components may then be sold
for the recovered, specific ferrous and r~on-ferrous metal values.
In a most preferred embodiment of the in~ention, as
illustrated in Figure }, a second crushing means 8, a second
separating means 9 and third separatin~ means 2, a third conveying
means lO and fourth conveying means 7, and a second magnetic means
1 are part of ~he recovery system. The second crushing means ~ is
similar to the first cLushing means 4 in that it further
selectively comminutes the carbonaceous incineration by-eroducts
to a diameter o~ preferably between about l/~ and l l/2 inches or
less, and most preferably l/2 inch or less, without comminutin~
associated ferLous and non-ferrous metal components. The
comminuted ash and associated ferrous and non-ferrous me~al
components from ~he second crushing means 8 are conve~ed by a
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third conveying means 10 ~o the first magnetic means ~1 or
separation of the ferrous metal components from the non-ferrous
metal components, such as aluminum. The third conveying means 10
may be again any conventional conveyor system, such as a belt
conveyor. The fourth conveying means 7 conveys carbonaceous
incineration by-products with associated ferrous and non-ferrous
metal components from the first se~arating means 6 to the second
crushing means 8. The fourth conveying means 7 may again be any
conventional conveyor system, such as a belt conveyor.
The second separating means 9 which separates further
comminuted carbonaceous incineration by-products and associated
ferrous and non-ferrous metal components from the second crushing
means 8 may again be any conventional separator, such as a screen
separator. Most preferably, the third conveying means ~0 and
second separating means 9 is a combination variable angle
vibrating screen/conveyor such as described above for the second
conveying means 5 and first separating means 6. Again, the screen
angle is preferably between about 10 and 45 degrees, and most
preferably between about 13 and 20 degrees, from the horlzontal
with the exact angle being selected to maximize the retention time
of the material on the screen without overloading the screen.
Similar to the combination second conveyor/~irst separator means,
the vibrating screen/conveyor of the second separator means/third
conveyor means combination has a plurality of openings, preferably
between about 3/8 and 1 1/2 inches, and most preferably about
3/4 inch, in diameter through which a further portion of the
vibrated ash or other comminuted carbonaceous incineration
by-product preferably less than about 3/4 to 1 inch in diameter
passes to a further collection station positioned below the
vibrating screen/conveyor. Preferably, the further collection
station is a conti~uation of the belt conveyor or other collection
device transporting the ash or other comminuted carbonaceous
incineration by-product that had passed through the first
vibrating screen/conveyor described above.
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The second magnetic means 1 is similar to the first
magnetic means 11 described previously and is used in the system
prior to the first crushing means, and preferably prior to the
ficst conveying means, to separate initially a portion of the
ferrous metal components, such as iron and steel components, from
the non-~errous components, such as aluminum components. The use
of such second magnetic means reduces the quantity of f eed
material delivered to the first crushing means and the other parts
of the recovey system.
A third separating means 2 prior to the first crushing
means 4 is preferably used in the system to separate
noncarbonaceous materials other than ferrous and non-ferrous metal
components, such as glass, sand and dirt, from the feed material
delivered to the first crushing means.
Although the invention has been described in detail in
the foregoing for the purpose of illustration, it is to be
understood that such detail is solely for that purpose and that
variations can be made ~herein by those skilled in the art without
departing from the spirit and scope of the invention except as it
may be limited by the claims.
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