The operating principle of batch asphalt plants
The feed bins store and weight the quantity of aggregates (virgin mineral) that undergo a heating and drying process using the energy from a burner. The material is put into the drum dryer from the opposite side of the burner and is dislocated in the opposite direction of the flame in the counter-flow process.
After the humidity is extracted, a bucket elevator transports the hot and dry materials to the top part of the weighing tower, which has a set of vibratory screens for the particle classification and the material is separated according to rock size and stored in hot bins.
Depending on the mixture needed, the dry material is weighed on the scales in these bins, which have the purpose of ensuring the correct proportion of each material in the mix through individual weighing.
The petroleum components, the binder (PAC), are measured by the scale and optional additives may also be put into the mixer. The system controls the mixing time. Once the process is done, the hot mix asphalt is sent to the storage silos or unloaded directly into trucks and sent to the road site.
The batch system is given this name because each load of materials inside the mixer is equivalent to one batch. The production from this type of plant is determined by the capacity of batches per hour.