Drying / Mixing
Before rock aggregate is mixed with other ingredients to make HMA, it is thoroughly dried. The drying and mixing process can be accomplished with one piece of equipment or the functions can be separated. Mixing can take place in a continuous process or in a batch process. Astec supplies a complete line of high-performance drying and mixing equipment to fill the varying needs of producers worldwide. Astec also provides pugmill type mixers which premix additives with rock aggregate.
Double Barrel® Dryer/Drum Mixer
Astec brings you the Double Barrel dryer/drum mixer, the mixer of choice over any other. The Double Barrel dryer/drum mixer combines the latest in hot mix technology with other great Astec features. Get guaranteed productivity and top quality mixes while keeping operating costs per ton of mix low and meeting the most stringent environmental codes. Stationary, relocatable and portable versions all perform to the same high standards.
Double Barrel® X™ Dryer/Drum Mixer
The Double Barrel X dryer separates the drying process from the mixing process, thereby providing a very reliable plant to be used for the purpose of recycling reclaimed asphalt pavement (RAP). The concept allows for RAP to be pre-conditioned through the external part of the DBX dryer, flashing off moisture in the drum, thus eliminating the problems associated with scavenger systems.
Double Barrel® XHR™ Dryer/Drum Mixer
The Double Barrel XHR system achieves a quality high RAP mix. To achieve this quality mix, Double Barrel XHR system utilizes an outer mixing chamber on the drum, an external mixer, and the V-Pac™ Stack Temperature Control System. The V-Pac™ Stack Temperature Control System allows the system to maintain as low an exhaust temperature as possible when running high RAP content. A stainless-steel drum and stainless-steel combustion flights withstand the higher temperatures associated with running high RAP. The Astec warm mix system comes standard on all Double Barrel XHR mixing systems.
UniDrum® Dryer/Drum Mixer
The unified drum is a high quality counter flow design that is offered in both portable and stationary arrangements. The UniDrum mixer is offered as part of complete new plants and also for retrofit applications, with a range of production capacities from 200 to 600 tons per hour (182 to 544 tonnes per hour) with 5% moisture.
Warm Mix Systems
Astec can retrofit warm mix systems to continuous mix and batch plants from any manufacturer, bringing the benefits of the Astec warm mix system to all asphalt pavement plant configurations.
Astec burners offer the latest in reliable burner technology combined with complete one-source responsibility. With retrofit capabilities, Astec is able to offer everything from a simple burner replacement to a complete installed system. Astec's burner group engineers the burners to the specifications of each customer and manufactures each in a new state-of-the-art manufacturing facility. Prior to shipment, each burner is tested on one of Astec's three tri-fuel (oil, gas & coal) test stands to ensure fast and easy start-up at installation.
To make good mix on a consistent basis, it is essential to add materials in the right order and at the right time. That's where the Astec exclusive sequential mixing process excels. The Double Barrel® dryer/drum mixer's long mixing chamber and stationary outer shell provide the ability for adding ingredients sequentially. Ingredients are added to the hot dry aggregate in an order that allows better temperature equalization and even distribution of all particles throughout the mix which results in better consistency.
V-Pac™ Stack Temperature Control System
ASTEC's patent-pending V-Pac™ Stack Temperature Control System extends the range of mixes that can be produced without requiring that the flights be adjusted. The system's "V-flights," unique drum flights with a deep V-shape, and its use of variable frequency drives (VFDs), which provide control of the drum rotational speed, are keys to the control system managing an asphalt plant's exhaust gas temperature and increasing overall efficiency.