Hot mix continuous asphalt plants with external mixer of parallel axis 

Series ME1600 and ME1800

Continuous asphalt mixing plants with external mixer of parallel axes are the most recent development of our company in the search for solutions for the continuous production of asphalt mixtures while in compliance with the strictest standards set forth by environmental agencies. The assembly of the plant on several mobile allows for easy transport through the Colombian mountain routes.

The ME series plants are manufactured in 3 models with maximal outputs of 100 and 140 TPH.

Drying of the aggregates is carried out in rotary drier drums, which operates in a counter flow manner, allowing for an increased efficiency of the heat transfer to the aggregates in comparison to the parallel flow plants.

The large diameter of the dryer drum allows the combustion gases to circulate at low speeds, reducing the entrainment of fine particles released from the aggregate supply.
The dryer is equipped with a thermal insulation coating to minimize heat losses.
The burner design has been the result of extensive experimentation with different fuels. It is equipped with Honneywell controls that allow the shaping of the flame for efficient heat transfer as well as manual or automatic variation of the heat rate, in order to achieve the exact temperature for the binding of the asphalt and aggregates.

The mixture between the dry aggregates, liquid asphalt, and recovered dust is made in a continuous mixer of parallel shafts with paddles, subjecting them to vigorous agitation and homogenization. The different configurations of the paddles allow for the control of the speed of the flow materials which in turn controls the mixing time.

The dust collection is carried out with two particle collectors. The larger particles are captured with an inertial collector while the finer particles are captured with a reverse flow sleeve filter, which has clean air flowing in reverse direction at low pressure in order to clean the sleeves. The sleeves are made with Dupont NOMEX (MR), making them resistant to temperatures up to 180 degrees Celsius and are easily washable. This technology eliminates the harmful use of compressed air for cleaning sleeves, which tears and impregnates them with oil. On the other hand, the use of this technology eliminates the use of pleated disposable cartridges, which are made of fabrics with low temperature resistance.

The filler recovered by the sleeve filter is sent to a silo where it is stored and fed to the mixer by an electronically controlled variable speed swivel gate.
The recovered material is returned to the mixer by means of a screw pump. Optionally, a screw pump can be supplied to discharge the recovered contents from the silo in the event of excess filler onto a truck.

The dosage of cold aggregates is performed with portable configurations of 3, 4 and 5 hoppers equipped with electronically controlled variable speed feeders. Optionally, a scalper may be installed between the collection conveyor and the conveyor that takes the aggregates to the dryer in order to remove over sizes.
The injection of the liquid asphalt into the mixer is accomplished with a flow control scheme powered by a Viking pump. The control system in place allows for a precise ratio of binder to aggregates to be achieved.

The plant is completely automated with a Siemens PLC that is equipped with a graphic HMI which also allows for the manual operation of any component of the plant.
Webster heavy duty chain lifts with anti-segregation hopper are supplied with the plant for the loading of the mix into trucks, or alternative heated silos with storage capacities of 30 to 50 tons may be used.

The basic model of this plant has a trailer that houses a 10,000 gallon tank for asphalt storage with its thermal oil heating boiler, a truck discharge pump and the flexible pipes and fittings necessary for its connection to the Asphalt plant, avoiding the manufacture of pipes in-situ.

All plants are supplied pre-wired to expedite their operation.
Optionally, it is possible to add recycled asphalt pavements (RAP) to the asphalt mixture through a damper located in the dryer’s reclaimer, which puts the RAP in direct contact with the hot aggregates to dry it. To allow for the complete RAP integration, an additional trailer is supplied with the plant that has a RAP feeding system that ensures the appropriate amount and sizes of RAP are supplied to the mixture. This system counts with hopper with variable speed band feeder with digital readings of the tons per hour supplied, followed by a scalper for removal of possible overtakes and a conveyor belt that delivers the RAP to the reclaimer of the dryer.

Additionally, rubber-asphalt injection is also possible, for which an additional pump station is supplied with a special pump designed specifically for this purpose as well as a digital weight-based control system for the correct supply of liquid rubber-asphalt.
Filler addition to the mix is also possible (Cal or Cement) by the installation of a silo for pneumatic load in the case of cement transported in cisterns or a conventional feeder when the feeder does not come in bulk.

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