How can it mix 50% RAP? To put it simply, because
e design of the RAP King drum mixer uses a
counter-ﬂow aggregate dryer that is surrounded by an
outer mixing chamber. is design allows residual heat
from the drying drum to be transferred outward to the
mixing chamber. Since considerable heat is involved in
Quality Hot Mix Asphalt. Simpliﬁed.
the drying process, a substantial amount of that heat
e RAP King™ drum mixer from CEI oﬀers hot mix asphalt is transferred to the full length of the mixing chamber.
producers a cost-eﬀective, well-built and proven counter- ere is enough heat to overcome the heat absorbed
ﬂow design capable of producing 180 tons per hour. by the incoming cold RAP. No additional heating is
It can produce mixes that include up to 50% RAP (Recycled needed to maintain proper mixing temperature.
Asphalt Pavement) with no added fuel cost.
Why RAP? Because it’s less expensive. It’s the same rock.
And, it is already asphalt-coated.
Many producers are realizing the lower material costs from
using RAP compared to virgin aggregate alone. Whereas
virgin aggregate must be mined from the earth, RAP is easily
obtained when existing roads are milled for re-paving.
And whether it comes from a quarry or a milled road, it’s the
same rock. For that matter, the rock already has AC (asphalt
cement) on it that can be incorporated into the new mix.
Residual heat from the inner drying drum is transferred
outward to the mixing chamber.
RAP King drum mixer Cold-Feed Bins
RAP Bin, Screen & Conveyor Baghouse and Control House
E X CE P T I O NAL LY
L OW E MISSIO NS
Airﬂow through the RAP King drum mixer cre-
ates a strong induced draft in the mixing chamber.
When steam and fumes are released from the RAP
as it mixes with super-heated virgin aggregate, they
are drawn out of the mixing chamber and back into
the combustion area where they are incinerated.
E X CE P T I O NAL LY
DU R AB L E
CEI products are well-made, designed for strength,
and constructed of heavy-duty materials. You’ll get all
the components you need, without paying for the ﬂuﬀ
that raises your overhead. And, CEI backs its products
with worldwide service and parts support.
e drum mixer and all other plant components are
chassis-mounted for easy portability. e entire plant
is designed for rapid setup and takedown.
Drag Conveyor and Surge Bin
— The Drum Mixer —
4. Liquid AC enters
3. RAP is added to mix
5. Fines are added to mix
1. Virgin aggregate
Emissions are pulled enters dryer
back into combustion
area and burned
6. Mix exits
2. Dry aggregate drops to
outer mixing chamber
The RAP King drum mixer features a proven design e standard burner used is a 49.3-million Btu/hour,
for making hot mix asphalt, including mixes with up to 50% gas-ﬁred burner. Special low-NOx burners, oil-ﬁred or
RAP. e design uses a counter-ﬂow aggregate dryer that is combination burners are available options.
surrounded by an outer mixing chamber. Residual heat from 2. Dry aggregate
the inner drying drum is transferred outward to the mixing drops to the outer
chamber, heating its full length. mixing chamber.
1. Virgin aggregate enters the dryer by way of a When the dry virgin
conveyor mounted on the gooseneck of the drum’s portable aggregate reaches the
chassis. Aggregate passes into the drum through an opening burner end of the dryer,
in the base of the knock-out box. it then enters the outer
e knock-out box features an access platform and doorway mixing chamber through
to allow for inspection and maintenance when the drum is a series of holes at the
not in operation. end of the drum.
Drop-out holes in drum
3. RAP is added to the mix through a dedicated
RAP inlet to the outer mixing chamber. e RAP inlet
chute is mounted near
the top of the drum.
Oversized RAP that
has not already been
screened is removed
Conveyor, knock-out box and ﬂights inside drying drum. through a special drop-
out chute mounted on
Once inside the drum, aggregate passes through a series of the RAP conveyor.
ﬂights that properly veil the rock through a burner ﬂame to
remove moisture. RAP inlet
RAP King drum mixer with optional low-NOx burner
4. Liquid AC is added through Liquid AC, virgin aggregate,
an inlet manifold mounted on the RAP and ﬁnes are all mixed
side of the drum. e AC is me- together as they travel the
tered with high accuracy and preci- length of the outer mixing
sion by a special two-pump asphalt chamber. e elongated mix-
meter. Mass-ﬂow type meters are ing chamber of the RAP King
also available. AC Inlet drum mixer oﬀers longer mix
5. Fines are added to the mix through a dedicated time than parallel-ﬂow mixers
inlet on the side of the drum. Fines are captured in of similar length. is proven
the baghouse and are returned to the drum mixer by a design produces a better,
series of screw conveyors. more homogeneous mix than
other drum mixers on the
e RAP King’s outer mixing Access to mixing chamber.
chamber features a full-length,
hydraulically-opened access door for inspection and mainte-
nance when the drum is not in operation.
6. Hot mix asphalt exits
the mixing chamber
through an outlet chute on
the side of the drum. e
outlet chute drops the mix
into the base of the plant’s
Screw conveyors return ﬁnes from the baghouse to the
— Cold Feed Bins — — RAP Bin —
Cold-feed bins with conveyor retracted for travel. RAP bin & conveyor feed RAP to drum mixer.
Scalping screen on incline conveyor. RAP bin unit includes its own scalping screen.
The 8’x12’ cold-feed bins are mounted on a chassis for The RAP bin is also mounted on its own portable
easy portability and rapid setup. e unit includes an inte- chassis and includes an integral scalping screen and in-
gral collecting-conveyor that runs underneath the aggregate cline conveyor. All motors and switches are pre-wired
bins. e conveyor includes an inclined extension that can and factory-tested.
be folded into a retracted position for travel. e RAP bin features steeply-angled side walls and a
e cold-feed bins feature steeply-angled side walls for reli-wider opening than the cold-feed bins. An air canon is
able feeding of aggregate. e unit is available with either 3 included to prevent material from sticking to the side
or 4 bins. All motors and switches are pre-wired & factory- walls and to ensure even, continuous ﬂow.
tested. Quick-plug connectors aid in rapid plant setup. A collecting conveyor underneath the bin drops RAP
Virgin aggregate is carried by the unit’s collecting-conveyor onto the unit’s scalping screen. Oversized material is
to a scalping screen. e scalping screen is mounted on a removed by the screen and drops away to the ground.
separate incline conveyor. Oversized material is removed by e unit’s incline conveyor then carries the screened
the screen and drops away to the ground. e incline con- RAP directly to the mixing chamber of the RAP King
veyor carries the screened aggregate to the drum mixer. e drum mixer.
conveyor includes an integral scale to monitor ﬂow of mate- Multiple bins are available to accomodate diﬀerent
rial to the mixer. gradations of RAP. is allows for better control of
gradations and asphalt content at higher recycle rates.
— Surge Bin and Drag Conveyor —
Drag conveyor is lined with Segmented, bolt-on sprockets
chrome carbide for durability. for easy ﬁeld maintenance.
The surge bin is mounted on a portable chassis and is a
crane-erected design. It is available in either 50-ton or 100-
ton capacity. Each size includes its own drag conveyor with
batcher. e drag conveyor features chrome-carbide liner for
durability, a heavy-duty drag chain, and segmented sprockets
for easy maintenance. e conveyor also features a full-
length stairway with platform around the batcher.
Control house, drag conveyor and 100-ton surge bin.
— Control House — — Baghouse —
Control panel inside control house. Portable baghouse with caged ladder & handrails.
The air-conditioned control house is The baghouse is mounted on its own portable chassis
trailer-mounted for easy portability. It also and includes air compressor, internal collecting auger, caged
includes heating, lights, internal power outlets ladder and handrails. e lower section of the baghouse
and a sliding ticket window. forms a hopper for collection of ﬁnes.
All plant controls are mounted on a centralized An inertial separator mounted at the baghouse inlet re-
panel inside the moves the majority of dust from the dryer prior to the ﬁlter
control house. A bags. Remaining dust and small particulate adheres to ﬁlter
PLC (program- bags that are suspended internally from the baghouse roof.
mable logic con- Powerful bursts of air are injected into the ﬁlter bags to make
troller) controls the dust break away and fall into the hopper below. e
mixing. collecting auger that runs the full length of the hopper car-
A larger control ries this dust, (or ﬁnes), out of the baghouse. Fines are then
house (shown returned to the drum mixer by a series of screw conveyors.
on page 3) is Access panels at the top of the baghouse allow easy chang-
available as an ing of ﬁlter bags. e baghouse also features multiple access
option. Standard Control House
doors for internal inspection and maintenance.