Astec Double Barrel^® Drum Mixer

Adjustable steel trunnions with railroad duty bearings.

Hot-forged from solid billets of alloy steel and precision machining provides ultra-smooth operation.

Thrust rollers on either side of the tire restrain the drum.

Bolt-on mixing paddles allow for easy maintenance.

The v-shaped notch allows material to start pouring out of the bucket at the beginning of each revolution. The material in the bucket continues to pour out until the rotation is complete. This is what provides an even veil of material. The v-flight is also larger than a traditional flight, allowing it to carry the same amount of aggregate even with the notch.

Provides greater uniformity of the aggregate veil through the gas stream during the drying process, across a wide variety of mix designs and tonnage rates.

A large hydraulically operated access door allows easy service of mixing shanks and tips from the outside of the drying drum.

4″ thick insulation under the outer skin of the mixing chamber minimizes heat loss and increases efficiency. In addition, temperature-resistant ceramic fiber insulation is used in critical high-heat areas.

Once heated and dried, the aggregate leaves the drying chamber and enters the mixing chamber. At this point, an infrared sensor measures the temperature of the hot aggregate and automatically adjusts burner output to keep aggregate at the required temperature. This unique Astec feature makes it easier to control mix temperatures and to consistently produce mix that conforms to specifications.

The Double Barrel drum mixer is also offered in a portable configuration.

The benefits of warm mix asphalt, such as reduced energy consumption, lowered emissions, and elimination of visible smoke, are well-known in the asphalt paving industry. Warm mix technology allows mix to be prepared and placed at lower temperatures than conventional hot mix. To achieve this, the viscosity of the liquid asphalt cement (AC) must remain low at the reduced temperatures. Maintaining a low viscosity at lower temperatures allows mix to flow freely through storage, transfer, and placement equipment and is more easily compacted. The Astec warm mix system injects a small amount of water into the liquid AC to create microscopic steam bubbles. These small bubbles reduce the viscosity of the liquid AC, allowing the mix to be worked at lower temperatures.