How to Choose a Road-Portable Compact Rubble Plant
Everyone wins when you bring the crusher to the jobsite.
Here’s how to do it
right.
by Carl Emigh
Choosing the best compact, road-portable rubble plant for your particular
needs may not be as easy as you think. Chances are you’re savvy enough and
will do enough investigating to keep from choosing a wrong plant. But even
some right plants are better suited to your needs than others. The trick is
to find exactly the right plant that’s ideal for your operation.
That difference can make a significant difference in your profitability.
Here are some factors to consider in your quest.
Are the crusher and screen mounted together in closed circuit on one
chassis, with the crusher on one end and the screen on the other? On the
plus side, these integrated plants save you from transporting the crushing
and screening plants separately. But there are other considerations as well.
- Combo crushing-screening plants are considerably longer than a crushing
plant alone. This affects maneuverability and your options in setup
configuration.
- Make sure the manufacturer has not sacrificed quality in components and
structural members to limit the overall weight on a single chassis. If a
plant you’re considering will require a hauling permit, they are normally
easy to get and certainly easier to live with than a plant cheapened for
weight
reduction.
- Make sure the plant allows ample room for smooth material flow and ready
access to all components — especially the crusher and discharge conveyor —
for maintenance and repairs. Without ample access room, it may be hard to
perform certain maintenance procedures, and some disassembly may be
required. Remember that minimizing downtime may be the most important factor
in your profitability.
 |
| The road mobile Grasan KR1010 primary impactor plant seen here
measures 8 feet, 6-inches wide; 12 feet, 6-inches high; and 45-feet long.
Like others of the genre, it can be hauled to a temporary site, set up
quickly, and crushes old pavement into value-added base at rates up to 150
tons per hour. |
 |
For most road contractors, on-site crushing means processing old concrete
pavement. For this application, the crusher itself must be a primary
impactor designed especially for concrete recycling. Preferably, the
impactor should have a fully automatic hydraulic cylinder system for
increased crusher capacity, smoother operation, and more uniform products.
Be sure the manufacturer is not using a secondary impactor modified for what
some might perceive as “light duty” primary crushing. Your mini-crusher may
not be used for “light duty” very often, if at all. While it is sized to
handle smaller throughput volumes, the impactor still must be engineered and
built for the rigors of heavy-duty work with minimum maintenance. Thus, the
mini-crusher should be a smaller but not a cheapened version of a full-size
primary impactor, offering the same kinds of features with no compromises in
design, performance, structural integrity of components such as side liners,
and blow bars.
The crusher inlet should be at least 36-inches wide. A small inlet may
require excessive pre-feed preparation to break up incoming materials. This
pre-feed prep with a hand-held pneumatic hammer or mobile hydraulic hammer
is time and labor-intensive and thus can be very costly.
Make sure the tons-per-hour capability of the crusher is sufficient for your
needs. How much rubble will you process per job and at how many sites per
day, week, or month? For most mini-crusher applications, 150 tons per hour
may be sufficient. However, for not a whole lot more cost, you can find
slightly larger, but still highly mobile, hydraulically controlled plants
that may crush up to 200 tons per hour.
There must be enough room under the crusher for metals and crushed materials
to flow freely onto the discharge conveyor in line with the material flow
for maximum efficiency and to prevent clogging. In addition, the magnetic
separator’s belt cleats, pulleys, and chutes should be made of a material
that will not magnetize, such as stainless steel.
Compare each manufacturer’s maintenance
recommendations.
Make sure wear parts are easy to replace. For example, a hydraulically
operated split housing on the impactor will save you many long hours of
downtime in replacing parts such as blow bars. And a hydraulic hood opening
will enable you to more easily unclog inlet jambs.
Always talk to experienced users of any plant you are considering.
There are many good equipment manufacturers, and each brand offers
worthwhile features or those companies could not stay in business. The
challenge is to find exactly the right equipment with features suited to
your particular needs.
Carl Emigh’s articles about aggregates production equipment are sponsored by
a variety of manufacturers in the field. This work was commissioned by
Grasan which manufactures a full line of quarrying equipment.
BID LIST
A Gallery of Mobile Crushing
and Screening Equipment
Why haul pavement rubble? On-site processing to produce value-added base
material has never been easier.
by Kirk Landers, Editorial Director
Grasan
Versatile screening and crushing plants
Grasan’s premier road portable screening plant is the 620HD-H. Designed
for use in quarries and pits, as well as for concrete recycling
operations, the unit
features a Deister 6- by 20-foot triple-deck horizontal screen with a
three-shaft, between-deck drive unit, as well as a side discharge
conveyor, under-screen fines conveyors, and extra heavy-duty frame and
walkways on three sides. Travel dimensions are 51-feet, 4-inches long,
and 13-feet, 6-inches high. The unit is mounted on a tandem axle trailer
with dual 11:00 x 22.5 tires.
The company’s largest road-portable crushing plant is the KRH1515. It
features the Hazemag APPH primary impact crusher with a fully automatic
hydraulic cylinder system that provides increased crusher capacity (up
to 600 tons per hour), smoother operation, and more uniform products,
according to Grasan. Designed for the on-site crushing of concrete and
asphalt rubble, as well as excavated rock, the crusher has a
45-inch-high inlet to handle larger sizes of material than other models.
A skid-on/skid-off hopper and six independent hydraulic support legs
allow for fast setup and tear down without a crane in about 30 minutes,
according to Grasan.
Click 13 on
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American Pulverizer
Trailer-mounted impactor
American Pulverizer’s APCO SRI 40x52 is a horizontal shaft impactor
mounted on a three-axle carrier that features hitch equalizing
suspension, 22,500-pound axles, and air brakes. The solid-rotor impactor
features a 0.375-inch plate, and an AR lined bypass chute from the
grizzly bars. Its vibrating grizzly feeder measures 46-inches wide and
about 17-inches high. The plant is powered by a 460-horsepower diesel
engine which is fed by a 320-gallon fuel tank. The heavy-duty impact
slider belt conveyor measures 48-inches wide.
Other features include a four-leg stabilizing arrangement tied to a
12-volt hydraulic package, an overhead self-cleaning magnet with a
5-horsepower rectifier motor, and a 100-KW generator to power the
conveyors and magnet.
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Metso Minerals/Nordberg
Complete process mobile plant
The Nordberg LT1213S is the newest member of
Metso Minerals’ mobile
crushing plant series for contractors. The company claims the unit is
the first mobile crushing plant on the market to provide “a really
complete crushing and screening process in a single unit for primary and
secondary applications.”
Its efficient screen module and return conveyor are said to allow the
LT1213S to produce one exactly calibrated product or two end products in
many different applications.
As a full process plant, the LT1213S crushes the feed material in an
impact crusher. The crushed material is screened with the inclined
screen and oversized material is returned to the crusher by the return
conveyor. The system can also be used in an open process to make two
different end product sizes.
The whole process can be controlled and adjusted according to the
specified end product requirements by means of the plant’s intelligent
PLC controlling system. The plant is said to be the lightest and most
compact unit in its class.
Click 16 on
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Major Wire
High performance screen media
Major Wire says its Flex-Mat 3 self-cleaning screen media is an
ideal choice for asphalt and concrete recycling operations. In asphalt
recycling applications, say the company, the stainless steel media
eliminates binding, especially in warm weather when the asphalt chunks
can turn hot and sticky. Flex-Mat 3 is recommended for top, middle, and
bottom screen decks.
For recycling concrete, when the problem is dust from fines, Flex Mat 3
is said to eliminate blinding that occurs with dry and dusty material.
For producing larger recycled concrete material, the company recommends
1- to 1.25-inch Flex Mat 3 to eliminate pegging. Major Wire says its
high-performance screen media can increase production of spec product by
20 to 40% compared to woven wire or polyurethane panels.
Click 15 on
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Sandvik
Intelligent crushing
Sandvik Mining and Construction designed the Crawlmaster H4800i to help
road construction contractors alone or in tandem with its 1208i. The new
model features the company’s Hydrocone 4800 cone crusher, while the
1208i uses a Jawmaster 1208 jaw crusher.
The “i” series of Crawlmaster mobile crushing units employ an
intelligent control system that provides vital information and
facilitates sequenced start-ups/close downs, as well as fault tracing.
Sandvik says its ASRi system gives the operator full control of the
crushing operation and provides an insight into the unit’s production
dates, history, and indications of service and maintenance.
Sensors at key locations assure trouble-free operation and safeguard
against breakdowns.
Material flow in the Crawlmaster series is controlled automatically, but
the option exists to manually override the system. If manual operation
is selected, each stem is simplified with user-friendly messages
explaining each function, step-by-step, according to Sandvik. In a
multi-stage process setup, such as when the 1208i and H4800i are used in
tandem, the ASRi system facilitates communication between the units.
Click 11 on
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The Screen Machine
Track-mounted crusher debuts
The Screen Machine Crushing Division has rolled out the 4043T Impact
Crusher, its latest tracked portable crushing plant. The unit features
Caterpillar tracks with high-speed travel and a 300-horsepower engine.
The 40- by 43-inch horizontal impact crusher has a 43- by 32-inch feed
inlet opening and fully remote controlled operation.
Other key features include a unique split housing design that allows for
blockage clearance during operation and ease of maintenance. Housing is
lined with replaceable and interchangeable hardened alloy sideliners.
The 40-inch diameter rotor has a one-piece shaft and variable speeds.
The three-stage crushing utilizes two interchangeable and replaceable
anvils and one fixed anvil and a hydraulic clutch to prevent downtime.
Click 14 on
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Telsmith
Severe-duty crusher debuts
Telsmith says its new Model 3258 Jaw Crusher delivers higher production
rates and lower costs per ton in severe-duty applications such as
processing very hard rock or challenging demolition debris. Its features
include a 32- by 58-inch feed opening and a uniquely long crushing
chamber with shallow nip angles to deliver aggressive crushing action
and consistent high-capacity throughput. Telsmith says the unit is
suitable for stationary operations and is compact enough to mount on
portable plants.
Telsmith says the new crusher incorporates a revolutionary hydraulic
adjustment and overload protection system that utilizes a moving toggle
beam. The system positions the toggle beam and holds the crusher
setting; hydraulic tensioning cylinders hold proper toggle tension
through the entire adjustment range and overload protection is
automatic.
Click 19 on
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Kolberg-Pioneer
Moves with highway demolition crew
Kolberg-Pioneer targeted road contractors as well as rock quarries with
its 2004 introduction of the Fast Trax line of track-mounted crushing
and screening plants. Included in the line are the FT 2650 jaw crusher,
the FT 4250(shown) horizontal shaft impact crusher.
The FT 4250 horizontal shaft impactor can be driven off its transport
trailer and start crushing concrete immediately, says the company. It
can crush on the go and windrow material. With an optional vibrating
screen package, it can produce up to three products simultaneously. A
400-horsepower diesel with hydraulic controls powers the entire plant.
For jobs requiring a jaw crusher, the FT 2650 plant weighs 105,000
pounds and is powered by a 245-horsepower diesel. The plant can produce
up to 400 tons per hour in hard rock or recycling applications.
Click 18 on
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Terex Pegson
Lower plant cost
Terex Pegson’s
1000 Maxtrak cone crusher, seen here on a California
highway and bridge project operating in closed circuit with a
Powerscreen Chieftain 1800 screen, features a proprietary Automax
all-in-feed design. The company says the design gives better throughput,
shape, and reduction for secondary, tertiary, and quaternary use. It is
also said to lower the overall plant cost and make it much less
complicated because there is usually no need for pre-screening between a
primary jaw crusher and the Automax.
According to the company, the all-in-feed system has lower friction loss
than other designs, resulting in more engine power being used to crush
rock — and greater productivity, cost efficiency, and fuel economy. The
hydraulic system can be quickly and easily adjusted, even while
crushing. And the company says there is no “bowl bounce” to cause costly
wear under extreme conditions.
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Reprinted from Better Roads Magazine
July 2006 |
