|Double Barrel Efficiency|
No matter what style or facility configuration you have, you can take advantage of the most thermally efficient dryer/mixer available – the Astec Double Barrel®.
Lower Your Cost Per Ton
What allows the Double Barrel dryer/drum mixer to make mix at lower cost compared to other drum mixers? There are two things. First, a unique design uses the entire drum length for drying. Other systems have to utilize one end of the drum as the mixing chamber, making the drying portion shorter. They then have to use higher temperatures to compensate for the shortened drying chamber. Astec's longer drying times let you dry more efficiently. Second, the material in the mixing chamber captures heat radiated from the drying process. A thick layer of insulation surrounded by the stainless steel shell holds heat in as well. No energy is wasted.
Run Clean, Even With 50% Rap
RAP enters directly into the mixing chamber and does not contact the hot gas stream of the dryer. This is an important advantage because the atmosphere in the mixing chamber minimizes emissions. The Double Barrel dryer/drum mixer runs clean, even at 50% RAP. Using recycle materials can produce significant savings without any loss of mix quality and without causing any visible emissions from the baghouse. Astec baghouse stack emissions meet federal standards even when high temperature (330°F) mixes are made.
Oxidation in the mixing chamber is minimized in the Double Barrel drum mixer. As recycle heats in the mixing chamber by contact with the hot aggregate, moisture in the recycle is driven off as steam. The steam atmosphere in the mixing chamber allows very little free oxygen and gas movement. Although steam may react with the liquid asphalt and vaporize some light oils, these vapors are drawn into the burner flame and incinerated. The same is true for emissions created by additives to Superpave or other modified mixes.