Rapidmix is a twin-shaft, continuous mixing plant for civil, environmental, and paving contractors. Mixer Intensity Effectiveness ensures a quality mix. Rapidmix is available in two options: Volumetric or Continuous Weigh. Details are provided herein and you can find more for your construction projects at www.rapidintl.com

1. Rapidmix Continuous
Mixing Plant Information

2. Rapidmix Continuous Mixing Plant Information
The Rapidmix is totally mobile and completely self-contained. It can be set-up,
erected and calibrated usually in about 4 to 6 hours. The Rapidmix is
completely self-sufficient with an on-board 250 kW. generator and Volvo Tier 4
Final diesel engine (on new models). The machine is electrically driven with the
exception of the hydraulic system used for set-up and erection of the
equipment. A touchscreen Allen Bradley PCL is at your fingertips to load and
store up to 100 recipes and control a majority of the continuous mixing plant
operations. The Rapidmix continuously monitors the in-feeds or weight of all
materials in the mix recipe. The aggregate bin offers a removable divider. A
48-ton silo has a throughput of up to 60 T.P.H. The 14 ft. mixing chamber
boasts twin-shafts with 72 Ni-Hard cast paddles which run at 110 R.P.M. that
ensure a homogeneous mix on a consistent basis of up to 400-600 tons per
hour. Additionally, the chamber is equipped with Siemens flow meter for your
water specs which is supplied by the on-board 1750-liter water tank. The
Ramsey belt scale or load cells take the final weight before moving material
along the out-loading conveyor, providing weigh tickets for a load or end-of-day
output results. The material is then transferred to the 1 cu. yd. gob hopper
which allows the ability to "hold" material for the next truck to fill. Wi-Fi
capability available.depends on it!
 Because you can't afford a bad mix, down time, or extra man hours.
-Your Reputation, depends on it!
www.rapidintl.com
rapsales@rapidintl.com
303-853-0068
Rapidmix Continuous Mixing Plant Information

3. Mixer Intensity Effectiveness
MIXER EFFECTIVENESS MEASUREMENT - TIME OR INTENSITY
The index of mixing difficulty for different materials and other confirmed
testing/research establishments is at its most difficult for paving concrete.
Rapid mixers have been developed using large blades in a specially phased
relationship which has been established by testing to give the most thorough
mixing possible with a wide range of products. They use gears to keep the
shafts in the correct phasing relationship. The relationship between each
mixing blade interaction must be constant for repeatable and continuous quality.
“Retention Time” is not a meaningful measure of mixing intensity for a
continuous twin shaft mixer. What matters is the number of blade interactions
with the material and the intensity of those interactions. Consider the following
cases:
MIXER COMPARISON: OTHER RETENTION
MIXER
RAPID
HIGH INTENSITYMIXER
Blades 10 72
Blade Size 0.1 m2 0.3 m2
Speed RPM 10 110
Retention Time in seconds 60 15
Mixer Intensity Effectiveness

4. Mixer Intensity Effectiveness
It is not difficult to grasp this concept by recognizing that the 72 bigger blades
(7.625" X 5.625" / 42.891 total square inches) of the Rapid High Intensity
Mixer, running at 110 rpm will provide much more intense and therefore,
thorough mixing.
Many specifications refer to “retention time” and call for reversible blades to
increase the mixing thoroughness. From extensive tests, Rapid has found that
the reversal of blades and restriction of the throughput by installation of wires
intended to increase the retention time, have no measurable effect on the
performance of a properly designed mixer other than to slow it down. (For
poorly designed mixers, those measures may have some effect.) Application
of such a specification approach is like substituting myth for scientific method.
Because HIGH Intensity mixers, as developed by Rapid, mix in a collision mode
rather than by slowly turning and folding the material, evaluation approaches
arising out of the “drum” mixer experience, or from rotating blade batch mixers
such as “pan” mixers, are not relevant. The Rapid mixing index has been
formulated to better define the performance expectations of a twin shaft mixer.
THE RAPID MIXING INTENSITY INDEX (MI)
Number of of mixing faces X speed (r.p.m.) X shaft centers (m.) X blade size
(m2) X phasing factor X pre-mix factor.
For a high intensity Rapid mixer, the phasing factor is taken as 1.00. For most
other types of mixers, the factor is between 0.7 and 0.9.
Mixer Intensity Effectiveness

5. Mixer Intensity Effectiveness
If the fine binder components, such as cement, are all pre-divided to each side
of the mixer before entering the mixer, the disbursement of the binder is more
rapid and thorough. In the Rapid layout, where this is practiced, the pre-mix
factor is taken as 1.0. However, if the cement is loaded onto the aggregate
belt or dropped into the mixer all in one place, a factor of 0.7 or less is
applicable. Greater factors of up to 1.2 can be applied for pre-slurred binder
mixes.
For thorough mixing, mixer intensities of more than 55 for Roller-Compacted
Concrete (RCC) have been established as being necessary to match field
results with laboratory results. For treatment of toxic wastes, a minimum index
of 80 is also recommended.
The power consumption of a continuous mixer varies for low strength cement
treated base with fine cohesive sandy materials, which are suitable for road
base, or in the sealing of waste contaminate areas. To ensure thorough mixing
of all kinds of materials, power available to the mixer should be at least 0.75
Kw per compacted cubic meter per hour of throughput. Less powerful mixers
cannot properly mix the more difficult materials.
Mixer Intensity Effectiveness

6. Mixer Intensity Effectiveness
Mixers with the following features may not produce satisfactory results in all
cases:
Mixers which run at relatively low speed (less than 110 r.p.m.)
They will have a low mixing intensity.
Mixers which have a small number of mixing faces of small size
Calculate the mixing intensity (MI) and be careful about applying such
mixers to critical mixing tasks.
Mixers of low specific power availability
Less than 0.5 Kw per m3 can only be safely used for clean washed and
graded aggregates. The mixing thoroughness of mixers with less than
that would require test investigation and verification.
Continuous mixing technology, if correctly applied, can produce results of
amazing consistency and productivity. If all factors are not correct, the results
can be very poor. This technology is intolerant of compromise upon correct
practice. Poor results are usually the accumulation of a number of seemingly
small compromises. The best way to be sure is to use a Rapid system which
has been designed for efficient and thorough mixing on a continuous basis.
Mixer Intensity Effectiveness

7. Volumetric or Continuous Weigh
CONTINUOUS MIXING OPTIONS: VOLUMETRIC or CONTINUOUS WEIGH
Continuous mixing—When the output of the mixer is equivalent to the input of
materials and the mixer can be operated without interruption to charge or
discharge material.
Volumetric measurement (C)—When the ingredients of concrete are flowing
continuously and measured by volume, by using a calibrated rotary opening, a
calibrated fixed-gate opening, or a combination of these, so that a known,
predetermined volume of each ingredient is obtained in a designated time
interval, the method of measurement is volumetric. Continuous volumetric
measurement with multiple ingredients requires that the proper relationship
among those ingredients be maintained. It is this calibration of speed and
volume which provides a smooth continuous release of materials resulting in
your next homogeneous mix.
Volumetric (C) Rapidmix Plant Attributes:
Ramsey Belt Scale
Rotolok Feeder: 750mm, off-set cleats, this prevents bridging in the
metering zone. These cleats are off set to insure there is material dumping
into the mixer at all times. ​
Models: 400C (up to 400 tons per hour) and 600C (up to 600 t.p.h.)
Rapidmix Continuous Mixing Plant Options

8. Volumetric or Continuous Weigh
Continuous Weigh (CW)- Materials are continuously weighed from the
aggregate hopper via load cells which weighs the material from the hopper to
the mixing chamber. The material from the silo, is collected in weigh
hoppers where the silo material is then dispensed into the mixing chamber for
an accurately weighed and mixed final product.
Continuous Weigh (CW) Rapidmix Plant Attributes:
Additional weight belt, weighing material from aggregate hopper to the
mixing chamber
Load cell suspended screw conveyor
Available Models: Trackmix250, 400CW or 600CW
For more Information:
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Volumetric or Continuous Weigh