“Be
fearful when others are greedy, and be greedy when others are
fearful.”—investor Warren Buffet.
There has never
been a better to time to make capital investments in your material recovery
facility. There—I’ve said it. Yes, you heard me correctly. Now is the time to
acquire as much equipment and plant improvements as you possibly can. How can I
possibly justify that statement when prices for scrap metal in particular and
recyclable materials in general have nosedived with the recent credit crunch and
the market meltdown?
Why? Because
equipment prices will never again be this low and financing will never be
cheaper than they are today. Demand for scrap materials has not gone away;
fearful economic times have depressed demand and economic activity. But as
Warren Buffet wisely pointed out, it is just such fearful times as ours that
present the best buying opportunities. Those factories in China and India that
have been ravenously consuming everything from copper piping to cardboard are
still there. They may currently be idle, but they are not going away. When (not
if but when) the economy recovers, pent-up
demand will soar and those material recovery facilities (MRFs) and recycling
operations that are the most efficient and most highly automated will dominate
the market during the upswing.
Not only will
you be doing yourself a favor by making capital investments to the greatest
extent possible, but you will also be hastening the inevitable recovery. This is
due to the “paradox of thrift,” the economic concept that if everyone saves more
money during times of recession, then aggregate demand will fall. When this
happens, it effectively lowers the total savings in the population. The paradox
argues that if everyone saves, then there is a decrease in consumption, which
leads to a fall in aggregate demand and thus leads to a fall in economic growth.
It is only natural to want to conserve cash and limit debt during uncertain
times. However, there is no other proven method of escaping a major recession
than economic stimulus—by government or by private industry.
The
Process
Recycling
systems at MRFs that emphasize automated sorting and processing equipment are
referred to by the nickname of “dirty MRFs.” They are said to perform
single-stream recycling since the waste arrives at the facility
in a single, unsorted stream. In contrast, MRFs whose recycling systems rely
heavily on manual sorting and processing of incoming materials are usually
referred to as “clean MRFs.” Their type of recycling process is referred to as
multistream recycling since major types of recyclable materials
are source-separated for ease of manual handling into individual wastestreams
prior to delivery to the facility.
It is the
former type of process, single-stream recycling, which benefits from capital
investment in sorting and processing equipment and automated control systems.
Yet, even here, some manual sorting is usually required and performed as an
initial step to separate paper and similar products from such bulkier items in
the wastestream as metals, plastic, and glass. The automated portion of the
recycling process utilizes the different physical and material characteristics
to perform a separating step that removes a unique material from the
wastestream. Further down the line, a different process separates out another
type of material, and so on, until every different type of material is extracted
and separated from the single wastestream flow.
Typically, the
first material to be removed is scrap metal. There are two types of scrap metal:
ferrous and nonferrous. To remove ferrous metals, the entire wastestream is
carried by a belt through a magnetic separator that pulls out the ferrous
metals. Although overhead magnets are often used, a more convenient
configuration puts the magnets under the belt. As the belt carrying the entire
wastestream passes over the magnets, the ferrous metal clings to the belts while
the rest of the waste falls off at a drop off point somewhat farther down the
line. As the belt continues back under its rollers, the ferrous metal sticks to
the belt until it is pried off by a scraper blade and falls into a collection
bin.
Nonferrous
metals (mostly aluminum foil and cans) are removed afterward by a similar
process called an eddy-current separator. An eddy-current separator utilizes a
spinning magnet with alternating polarity to induce an electrical current in the
nonferrous metal. The resultant electrical current creates its own magnetic
field around the piece of otherwise nonmagnetic scrap metal, which creates a
repulsive force against the rotating magnetic field. The induced magnetic field
is repelled by the magnetic field utilized by the eddy-current separator, and
the nonferrous metal literally leaps off of the processing table or belt into an
adjacent collection bin.
Nonferrous
metal can be further separated by an air knife, a device that can separate light
aluminum foil from heavier metal cans. The “knife” refers to sheet flows of
high-velocity air blasts arranged in a parallel sequence. The force of the air
blasts lifts the aluminum foil from the heavier cans. Swirling and remixing are
prevented by the separation distance between the sheets of airflow. Each type of
recovered metal can be compressed in a metal baler for convenient shipping and
resale.
The remaining
wastestream (primarily cardboard, but also including plastic, glass, paper, or
wood) continues on to disc screeners that sort by both shape and size. Waste
enters the screeners’ inflow bin by means of a variable-speed conveyor belt that
regulates the rate of movement. By altering the speed of the belt, the operator
can even out the flows of incoming waste and prevent clumping, clogging, or
exceeding the machine’s operating capacity. Disc screens consist of a floor
covered with rotating discs of different sizes and shapes (circular, oval, or
star,) depending on the type of material being processed. The opening sizes can
be adjusted to manage different types of materials. The resultant wave motion
carries larger and lighter objects higher, while heavier small objects (such as
glass shards) move to the lower portion of the separator and drop through holes
in the screen floor.
During these
various operational stages, it is inevitable that a significant fraction of the
glass portion of the wastestream gets broken into shards. These shards, as well
as other objects, pass through a rotating trommel. Trommels are rotating drums
equipment with small holes (usually about 2 inches in diameter) in the side and
directional vanes that promote gravity separation on their interior walls.
Usually, the trommel’s axis of rotation is at some angle to the horizontal to
facilitate the discharge of material (a horizontal axis would result in too slow
of a flow through, while vertical would be too fast). In addition to sorting
vanes, more complicated trommel designs utilize flights that carry the material
back up to the high end of the trommel for another pass through. This process
sorts large pieces of glass and cullet suitable for recycling from small pieces
that become residue.
Glass pieces
large enough to be recycled can be further separated by a color sorter. This
optical sorting mechanism divides glass pieces by their various colors (brown,
amber, green, clear, and mixed.) Glass sorters rely on light spectrophotometry
that can distinguish between various colors of glass by measuring the
wavelengths of the visible light reflected back at the optical sensors. Ceramic
material, on the other hand, is completely removed from the glass waste, after
which the glass can be sorted by color. Once finally separated, the individual
colored glass shards get sent through a glass pulverizer that reduces their size
and consolidates their volume for shipping and resale.
Plastic waste
objects (mostly bottles and other types of containers) also go through a
subsequent sorting process. Containers and cartons are separated from bottles
and flattened by a plastic baler. The bottles are further separated by the
various types of plastics (HDPE, PVC, PET, etc.). The various types of plastic
are ground down into particles by a granulator, and then compacted by a baler
prior to shipping and resale.
Meanwhile, the
paper waste that was initially separated from the wastestream undergoes its own
recycling process. It also can be passed through a rotating trommel to separate
mixed paper products from unusable residue. The residue falls out of the small
holes on the sides of the trommel’s drum while the reusable paper passes through
and continues with the sorting process. After this point, manual sorting is
usually required to separate out the various types of paper (glossy magazines,
newsprint, office paper, etc.). Each kind of paper is fed into its own baler for
compaction and binding prior to transport to resellers.
A type of
separator often used to separate mixed paper streams (as well as other
lightweight materials) is the air classifier. This can be used at the start of
the process to separate out paper waste from the general wastestream and avoid
manual separation. Lighter materials are separated from heavier materials by
means of a high-velocity airstream induced in a stack structure by a powerful
blower installed at the top that sucks air up the shaft. Waste is fed into the
stack at about the mid point. Below the waste feed is an air inlet controlled by
a rotating airlock. Heavy objects fall to the bottom of the stack for removal
and further sorting or disposal as unusable residue. Lighter materials are
sucked up to the top of the stack. Often the air-separator stack is equipped
with a cyclone separator that causes the light materials to lose their velocity
and settle out based on their relative density and size.
Prior to
transport for resale, almost all types of recycled materials are compacted to
smaller volumes and higher densities by means of compactors designed to handle
each type of material. Often, the compacted mass is further bound up with string
or wire to ensure structural integrity during transport. Low-density materials
(cardboard, aluminum cans, newsprint) especially need compaction to reduce what
would otherwise be extremely high per-ton transport costs. Compactors are
electronically controlled hydraulic systems sized for a particular task and
anticipated flow through quantities (tons of materials per hour).
In many ways,
shredders, which are the operational opposite of compactors, are also useful,
especially at the start of the process. Not everything that comes into a MRF is
easily sorted cans and cardboard. Large objects and bulk items such as
appliances and tires must be recycled as well, and these have to be shredded to
segregate the individual materials used in their manufacture. Once the metal and
nonmetal fragments have been produced, they can be added to the general
wastestream and processed in the same manner as curbside waste.
Major
Suppliers
Continental
Biomass Industries is a manufacturer and supplier of chippers, grinders, and
shredders. Its Grizzly mill is a fixed grinder that is primarily designed as a
wood hog. However, it can be reconfigured specifically as a primary, secondary,
or tertiary grinder for demolition debris, MSW, yardwaste, or wood debris. The
Model 8400 is a mobile (track- or wheel-mounted) unit that can operate with four
different rotors, allowing it to grind a wide variety of materials, including
contaminated construction debris, railroad ties, and MSW. CBI Shredders can be
either portable or stationary with either electric or diesel drives. They can
handle for high-volume primary processing of metal-contaminated C&D (rebar
stuck in concrete chunks), bulky waste, or MSW. The Annihilator can process more
than 100 tons per hour of MSW. Its heart is a 6-inch forged steel, 20,000-pound
rotor with reversible tips. It is capable of being operated in auto reverse, and
has as automatic purge cycle for easy cleaning. The CBI prescreener is usually
used as a prefeeder in conjunction with a Grizzly grinder. It separates out
abrasive fines, reducing wear and tear on the Grizzly and increasing its
productivity.
Doppstadt US
supplies volume-reduction equipment for the recycling industry including low
speed shredders, trommel screeners and high-speed grinders. Their DW series slow
speed shredders emphasize efficiency. The DW can handle different applications
and loads with very low fuel consumption. It can quickly process MSW or more
slowly process contaminated construction and demolition debris as well as bulky
land clearing waste. The company’s SM series trommels provide operational
versatility and screen sizing changes needed for multiple applications including
topsoil, multiple C&D streams and MSW. Doppstadt’s AK series grinders
utilize precision to control the consistency of the materials being fed into the
hammer mill. These materials include wood and wood products such as dimensional
lumber, greenwaste, and land-clearing debris.
Weima America
produces an extensive range of size reduction equipment that includes
single-shaft shredders, four-shaft shredders, horizontal shredders, granulators,
two-stage recycling systems, and briquetting presses. The company’s WL(K) series
shredders are low-speed, low-rpm machines designed for the recycling industry,
capable of shredding all types of wood, paper, plastics, and more. They utilize
V-Rotor technology with mounted cutting knives capable of handling abrasive
materials and allowing for easy removal and replacement. The system is
adjustable, allowing for variable knife projections and optimized cutting
geometry producing consistent particle sizes.
Newly
introduced by Weima is the “E-Rotor” WLK shredder. The purpose of the new rotor
is specifically for the recycling of film and fibrous materials. This includes
the historically tough-to-shred woven and nonwoven fibers. The design has also
eliminated wrapping issues with thin gauge films and fibers that sometimes
occurs with other rotor designs. One of the many benefits to the new E-Rotor
design is that it generates a relatively high bulk density when processing film.
This helps to maximize the efficiency of the repelletizing process.
The ZM series
is the company’s four-shaft shredders, often used in such applications as
cardboard boxes, electronic hard-drive media, medical waste, veneer, and bulky
plastic materials. These shredders are typically used to handle waste as it is
generated in a manufacturing process rather than in a separate
shredding/granulating room.
The company’s
horizontal line of shredders range from the Beaver, designed for low-volume
applications and sized to fit in confined spaces, to systems like the Jaguar and
Tiger, which allow for greater-volume operations. Horizontal shredders are ideal
for wood strips being produced from ripsaw lines or for plastic deck boards or
profiles. Weima’s largest horizontal machine, called the Leopard, has a patented
tank-track infeed roll design that gives the shredder the ability to grab stacks
of materials from strips to bulky block waste all at once, allowing for more
versatility and greater output.
Weima’s line of
briquetting equipment has become increasing popular in the wood and paper
industries. This equipment takes wood chips, sawdust, shavings, or even paper
dust and compresses it to what looks like an oversized hockey puck. The major
benefit of this equipment is that it reduces the amount of loose material and
waste bins and allows for easy transport and removal. The additional benefit is
that it has a great Btu value, allowing the customer to burn the material in
existing boilers. It is also a great alternative when security is an issue and
complete destruction is needed.
Other
equipment, such as the NZ granulator, is capable of regrinding small- to
medium-size particles in a two-step process. This is typically put in place
after the WLK preshredder for materials that need to be reduced to less than
three-eighths of an inch in particle size.
Weima also
manufactures equipment for the MSW and refuse-derived fuel (RDF) industries. Its
Energy Line consists of four different models. The Weima PreCut is a
single-shaft preshredder for unsorted highly contaminated material streams and
is ideally utilized as the first step of multistage waste processing. The Weima
PowerLine is a high-capacity secondary shredder in a multistage operation or a
single-stage shredding solution for clean material streams from post-industrial
waste. Equipped with the technology of the PowerLine, the new EcoLine is
designed for small to medium throughput requirements, regardless of whether it
is used in a single-stage operation or as a secondary shredder. Featuring a
high-speed rotor, the FineCut is designed as a secondary grinder in a multistage
recycling/RDF plant.
Bulk Handling
Systems LLC provides turnkey solutions for material recovery facilities. The
company has established a new, patented MSW process that has achieved a
recycling rate of over 75%, keeping this waste out of landfills and capturing
90%–99% of high-value commodities like PET plastics with a single operational
cycle. Beginning with the BHS Bag Breaker (an important and often neglected
first step) which eliminates the need for manual bag opening, waste is carried
to the various processing stations in the BHS recycling system by means of
heavy-duty chain belt, idler belt, sort belt, and slider bed conveyors. The BHS
Debris Roll Screen sorter can process MSW, C&D, greenwaste, compost,
plastic, glass, and tires. Its patented design provides efficient material
agitation and separation with operation versatility provided by variable speed
and disc drive with fine-tuning provided by angle adjustments. Following the
bulk sorting, the wastestream passes through BHS’s patented combination of
technologies, including BHS Polishing Screens, air systems, and optical units.
The Polishing Screens utilize BHS’s no-wrap disc design and remove fibers and
containers for separate processing.
CP
Manufacturing, a division of the IMS Group of companies, provides turnkey
solutions for the separation of recyclable materials. CP designs and builds
entire systems meeting its clients’ requirements. These systems process
curbside, picked-up, commingled containers (glass, plastics, aluminum, and
steel) and fiber (OCC, ONP, mixed paper, and containers) in a single automated
system. The key to efficient sorting is the patented disc screen technology.
CP’s disc screens are engineered to optimize separation while minimizing
downtime and maintenance costs. Though unique to each need and specialized in
design, CP’s MSW processing systems follow an optimized work flow: presorting,
fine-screening and residue removal, magnetic and eddy-current separator,
container and paper screens, container processing, and fiber processing. In
addition to the company’s MSW processing systems, CP also offers solutions for
single-stream, C&D, and waste-to-energy processors with its heavy-duty,
automated separation equipment, having custom-designed, fabricated, and
installed over 300 MRFs worldwide to maximize the customer’s processing time
while lowering costs.
Allegheny
Shredders is a premier manufacturer of high-capacity shredding systems with
capacities from 1 to 25 tons of paper per hour. In addition to Allegheny's
complete line of high-capacity shredders, the company also manufactures
cross-shredding systems, security grinders, product and e-scrap shredders,
conveyors, tippers, horizontal balers, dust collection, and auto-feed systems.
So whether you need to destroy documents, wastepaper, plastics, products, or
e-scrap, Allegheny has a practical solution to meet your needs—and your budget.
To complement Allegheny’s line of equipment, the company also provides expert
consulting for collecting to processing to recycling for a profit.
B.E. Equipment
sells and services new and used recycling, waste-reduction, and solid waste
handling equipment. The company offers a wide variety of new, reconditioned, and
used recycling equipment, including balers, conveyors, sorting systems,
shredders, commercial/industrial compactors, core strippers, and briquetters.
Flexible finance options allow customers to purchase or lease the equipment. The
company also provides transport, installation, maintenance, and training
services. Its used equipment, often obtained from liquidation operations,
includes reconditioned and renovated equipment with upgraded or restored
operational performance. Its inventory includes equipment from all the major
industry manufacturers and suppliers, along with an extensive supply of spare
parts.
Machinex
Industries offers complete, custom-engineered sorting and recycling systems for
specific applications. This includes a line of specialized conveyors and the
company’s Mach Series material separators. Machinex offers a complete package of
single-stream Mach separators. It achieves a high level of sorting purity and
efficiency made possible by its highly adaptable deck systems. Sorting
configuration flexibility gives the possibility to adjust to any material
stream. Variation of deck-angle speed and screening configuration are key
elements to system flexibility. The Mach sorters are also fully adaptable,
allowing for full integration into existing setups. Design modifications can be
quickly made to meet specific needs. But Machinex has an added ability to
integrate multiple processing applications into whole systems that can be
developed as turnkey operations for MSW waste processing. The company’s
front-end processing equipment maximizes recycling recovery rates through
optimizing the various components combined with detailed MRF design-consulting
services. Its peripheral equipment includes conveyors, bag openers, trommels,
disc screens, magnetic and eddy-current separators, and electric controls.
Sennebogen of
North America offers a green line of bulk material handling equipment. The
company’s Model 305c Multi-Hander can be described as a cross between a
front-end loader and a cherry picker, which makes it extremely useful for
managing recycled materials. In this unique design, both the bucket and the
operator’s cab can be raised by lifting arms. The ability to elevate the cab
during operations provides superior visibility for the operator. Its articulated
bucket is specially designed to allow it to compact in-place materials that it
has loaded into dumpsters. With a 124-horsepower power plant, it is capable of
lifting up to 11,000 pounds in a single load. Operational versatility is
provided by multiple types of buckets and attachments for different jobs (light
material bucket, bucket with hydraulic clamp, bucket with teeth, fork lift,
lumber forks, snow plow, orange-peel grab, and log grapple). A wide wheel base
and tight turning radius provided by its independently turning wheels combines
stability with maneuverability. Larger versions include the Models 821M and
821R. Both are powered by a 142-horsepower engine and can lift 54,000 pounds and
51,600 pounds respectively. Designed for managing larger objects, these machines
come equipped with grapples or magnet attachments. Their large boom lengths and
stabilizing footpads make them suitable for large-scale outdoor use.
SSI Shredding
Systems produces a line of shredders for multiple applications capable of
efficient product destruction and volume reduction. The company provides four
model types: Uni-Shear, Dual-Shear, Quad, and PRI-MAX. The Uni-Shear (a one
shaft shredder) can process materials such as plastic, paper, and nonferrous
metals into chips measuring three-quarters of an inch to 3 inches in size at a
processing rate of 0.5 to 5.0 tons per hour. It is also useful for the secure
destruction of documents and computer files. Its single-rotor design
incorporates a ram-assisted vertical feed. This PC-controlled “smart ram”
improves processing operations, minimizing downtime due to clogging. Depending
on the materials being processes, the Dual-Shear (two-shaft shredder) can
process 0.5 to 20 tons per hour into strips of varying lengths. It can handle a
variety of materials, including metals. Its rugged construction allows for such
severe operating modes as the shredding of batteries, tires, or hazardous waste.
This is made possible by a high-torque shearing design that is driven by an
energy-efficient low-horsepower motor. Heavy-duty shredding is provided by the
Quad (a four-shaft shredder). A major advantage of the Quad is a controlled
particle size using low-speed technology, because a screen is integrated with
the shredder. The largest-scale shredding operation is provided by the PRI-MAX,
a primary reducer. Capable of processing almost any material, it can mange both
bulk and mixed waste (furniture, appliances, railroad ties, asphalt shingles,
tires, and automobile parts). Operating at a process rate of 5 to 150 tons per
hour, the PRI-MAX produces shredded chunks measuring 6 inches to 24 inches in
size. It comes with single-shaft or dual-shaft cutting tables with programmable
operating modes depending on the material being processed.
Eriez
Magnetics is a supplier of eddy-current separators, magnetic separators, and
drum separators. In fact, back in 1969 the company patented the permanent
magnetic and electromagnetic eddy-current separators alike. Inside a drive
rotates the rare-earth magnet rotor at a high rpm. Simultaneously, a conveyor
belt rotates the external drum at a slower speed. As a result, the fixed magnets
generate a current in the nonferrous metals in the wastestream travelling along
the conveyor belt to create the repulsive magnetic fields. The company’s type-M
eddy current separator is specifically designed for MRFs. Built on an 8-inch
steel frame, it comes equipped with a compact, reinforced tapered hood, easily
removable access panels, URO urethane conveyor belt, and variable-speed rotors
and belts. Operations are controlled through NEMA 12 rotor logic and motor
starters. Matching the performance of the eddy-current separator is Eriez’s
magnetic-drum separator. Equipped with either fixed or electromagnets, the
separators utilize different configurations. The All Electro Agitator type
utilizes rectangular core pickup magnets creating deep magnetic fields that grab
even thick accumulations of ferrous metals. As it does so, it flips and agitates
the ferrous metals, cleaning it of unwanted residue and contaminants. Its
non-agitator design utilizes a transfer magnet to carry ferrous metals around
the drum and into the collection bin. Scrap drums have wider magnetic fields to
handle increased tonnage.