Working principle of drying and heating system in asphalt mixing plant
The basic production process of asphalt mixture includes dehumidification, heating and covering of aggregate with hot asphalt. Its production equipment can be basically divided into two types in terms of operation method: intermittent type (mixing and discharging in one pot) and continuous type (continuous mixing and discharging).
The parts used to cover hot aggregate with hot asphalt in these two types of asphalt mixing equipment may be different, but when it comes to drying and heating systems, both intermittent and continuous types are composed of the same basic components, and their main components are drying drums, burners, induced draft fans, dust removal equipment and flues. Here is a brief discussion of some professional terms: intermittent asphalt mixing plant equipment consists of two different parts, one is the drum and the other is the main building.
The drum is arranged on a slight slope (usually 3-4 degrees), with a burner installed at the lower end, and the aggregate enters from the slightly higher end of the drum. At the same time, hot air enters the drum from the burner end, and the lifting plate inside the drum turns the aggregate through the hot air flow repeatedly, thus completing the dehumidification and heating process of the aggregate in the drum.
Through effective temperature control, the hot and dry aggregates with suitable temperature are transferred to the vibrating screen on the top of the main building, and the particles of different sizes are screened by the vibrating screen and fall into the corresponding storage bins, and then enter the mixing pot for mixing through classification and weighing. At the same time, the hot asphalt and mineral powder that have been measured also enter the mixing pot (sometimes containing additives or fibers). After a certain period of mixing in the mixing tank, the aggregates are covered with asphalt layer, and then the finished asphalt mixture is formed.