The drum is also mounted on a slight slope. However, the igniter is placed at the higher end where the aggregate enters the drum. The dehumidification and heating process, as well as the addition and mixing of hot asphalt and mineral powder (sometimes with additives or fibers), are all completed in the drum. The finished asphalt mixture is transferred from the drum to a storage tank or a transport vehicle.

The drum is a component used in both types of asphalt mixing plants, but the method of use is different. The drum is equipped with a lifting plate, which lifts the aggregate when the drum turns and then allows it to fall through the hot air flow. In intermittent plants, the lifting plate of the drum is simple and clear; but the design and application of continuous plants are more complicated. Of course, there is also a ignition zone in the drum, the purpose of which is to prevent the flame of the igniter from directly contacting the aggregate.
The most effective way to dry and heat the aggregate is direct heating, which requires the use of an igniter to direct the flame directly into the drum. While the basic components of the igniter in the two types of asphalt mixing plants are the same, the size and shape of the flame may be different.
Although there are many ways to design induced draft fans, only two types of centrifugal induced draft fans are commonly used in asphalt mixing plants: radial impeller centrifugal fans and backward impeller centrifugal fans. The choice of impeller type depends on the design of the dust collection equipment associated with it.
The flue system located between the drum, induced draft fan, dust collector and other related components will also affect the working conditions of the asphalt mixing plant. The length and structure of the ducts must be carefully planned, and the number of ducts in intermittent systems is more than that in continuous systems, especially when there is floating dust in the main building and it must be effectively controlled.