General Process of Asphalt Mixing Plant
Asphalt mixing plant is a complete set of equipment used to produce asphalt for road pavement. It is mainly consisting of cold aggregate supply system, drying system, burning system, hot mix elevator, screen, weighing and mixing system, bitumen supply system, dust collection system, hot asphalt storage silo and control system.
Here is a brief introduction how asphalt mixing plant works.
Standard working condition
Standard working condition has direct influence on its output capacity and asphalt quality. To make a purchase or understand its working process, we should know this. It refers to a condition where the asphalt mixing plant operates under standard atmospheric pressure, ambient temperature is 20160℃, moisture content of aggregate is 5%, batching circle lasts 45s (for batch mixing plant), and the finished asphalt is middle-sized particle.
The process includes 1) cold aggregate heating, 2)drying and measuring, bitumen heating and measuring, and 3) hot aggregate and bitumen mixing.
As shown in above flowchart, the detailed processes are as follows.
1. Different sized aggregates will be sent to hoppers for coarse screen, then delivered by the belt conveyor to the drum dryer. Once being dried and heated to the required temperature, the aggregate will be lifted by hot mix elevator to vibrating screen and stored in the silo after screening. After this, the aggregate will be precisely weighed for mixing in the twin-shaft mixer.
2. Mineral powder stored in filler silo will be weighed and sent to twin-shaft mixer.
3. Bitumen in the bitumen tank will be heated first, then supplied to twin-shaft mixer at certain volume as binder.
4. The well-mixed asphalt will be carried by elevator to storage silo or discharged into the truck directly.
5. The dust from drum dryer and vibrating screen etc will be collected by the dust collection system like baghouse dust collector and recycled as filler or mineral powder.