Note: Descriptions are shown in the official language in which they were submitted.
SYSTEM FOR RECOVERY OF SALVAGEABLE 1~ 4 n 4 7
FERROUS AND NON-FERROUS METAL
COMPONENTS FROM INCINERATED WASTE MATERIALS
FIELD OF THE INVENTION
The present invention relates in general to 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
materials. The present invention further relates to a crusher
for selectively comminuting friable material without
comminuting associated 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 sanitary
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.
Recovery 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 ferrous materials, from solid waste products
are known in the prior art, e.g., U.S. Patent Nos. 3,549,092;
3,659,396; 3,788,568; 3,790,091; 3,973,736; 4,020,992;
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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 fully 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 the 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 associated ferrous and non-ferrous metal
components. Such a system will not only permit the recovery
20 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.
2 5 SUMMARY OF THE INVENTION
The present invention pertains to a system for
recovering salvageable ferrous and non-ferrous materials from
incinerated waste materials including friable, carbonaceous
incineration by-products such as ash, and associated ferrous
30 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;
... . . .
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_ and first magnetic means for separating ferrous metal
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 crushing means and collection stations for
collecting separated comminuted carbonaceous incineration
by-products, ferrous metal components and non-ferrous metal
components. 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-ferrous 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 first separating means to the second
selective crushing means.
The present invention further relates to a method
for recovery of ferrous and non-ferrous metal components from
incinerated waste materials using the system of the present
invention and to a novel crusher for selectively comminuting
friable materials without comminuting associated malleable
materials.
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IOA7~
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a process schematic diagram of a
preferred 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 present invention.
Figure 3 is a cross-sectional view taken through
line A-A of the preferred selective crusher of Figure 2.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is directed to a system for
recovering salvageable ferrous and non-ferrous materials 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
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
separating comminuted carbonaceous incineration by-products
from ferrous and non-ferrous metal components; and first
magnetic means for separating ferrous metal components from
non-ferrous metal components.
The feed material processed in the recovery system
generally consists of the bottoms or ash material remaining
after incineration 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 incinerated 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. Although incinerated waste materials are the
1340 l76
~- preferred feed stock of the invention, other feed materials,
including ash and ash-related products and non-ferrous and/or
ferrous metal components, are also suitable.
Referring to Figure 1, 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
first conveying means 3 may be a belt-type conveyor at an
angle from the horizontal, i.e., troughing angle, of between
preferably about 10 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
means 4 to a first separating means 6. The second conveying
means 5 may again be a belt-type conveyor or any other
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 10 and 45
degrees, and most preferably between about 13 and 20 degrees,
from the horizontal, with the exact angle being selected to
maximize the retention time of the material on the screen
without overloading the screen. The vibrating
screen/conveyor has a plurality of openings, preferably
between 3/8 inch and 1 1/2 inches, and most preferably about
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3/4 inch, in diameter, through which a portion of the
vibrated ash or other carbonaceous incineration by-product
preferably less than about 3/4 inch to 1 inch in diameter
passes to a collection station positioned below the vibrating
screen/conveyor. The collection station 12 may be any
conventional 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 or non-ferrous metal
components. The crusher is preferably a single rotating
roll-type crusher 20, such as shown in Figures 2 and 3,
having a plurality of, preferably two to 8iX, and mo8t
preferably four, tungsten carbide welds 30 equidistant-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 rotating roll-type crusher 20 where
they are delivered to the rotating roll 32. The rotating
roll 32 is set a sufficient distance from the backing plate
3~ to comminute the carbonaceous incineration by-products to
a diameter of preferably between about 3/8 to 1 1/2 inches or
less, and most preferably 1 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, hydraulic cylinders or other means which
serves as a release device, compressing when ferrous or
non-ferrous metal components in the incinerated waste
materials enter the space between the rotating roll and the
backing plate at a pressure sufficient to comminute the
carbonaceous incineration by-products, but insufficient to
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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 + 10 psi and release and return to
place almost instantly when a ferrous or non-ferrous metallic
component enters the space between the rotating roll and the
backing plate and is passed. The ability to vary the air
pressure is desirable in order to be able to comminute the
various carbonaceous incineration by-products encountered
from the same or different incineration processes.
The ferrous and non-ferrous metal components are
separated in the claimed system by first magnetic means 11.
The first magnetic means 11 may be used in the system prior
or subsequent to the first crushing means 4. Preferably, the
first magnetic means 11 is used in the system subsequent to
the first crushing means 4. The first magnetic means 11 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 12. 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 non-ferrous metal values.
In a most preferred embodiment of the invention, as
illustrated in Figure 1, a second crushing means 8, a second
separating means 9 and third separating means 2, a third
conveying means 10 and fourth conveying means 7, and a second
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magnetic means 1 are part of the recovery system. The second
crushing means 8 is similar to the first crushing means 4 in
that it further selectively comminutes the carbonaceous
incineration by-products to a diameter of preferably between
about 1/4 and 1 1/2 inches or less, and most preferably 1/2
inch or less, without comminuting associated ferrous and
non-ferrous metal components. The comminuted ash and
associated ferrous and non-ferrous metal components from the
second crushing means 8 are conveyed by a third conveying
means 10 to the first magnetic means 11 for 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 separating 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 10 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 horizontal 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/first separator
means, the vibrating screen/conveyor of the second separator
means/third conveyor means combination has a plurality of
' ' 1340~7~)
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 continuation 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.
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 first conveying means, to separate initially a portion
of the ferrous metal components, such as iron and steel
components, from the non-ferrous components, such as aluminum
components. The use of such second magnetic means reduces
the quantity of feed material delivered to the first crushing
means and the other parts of the recovery 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 therein 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.
