Counter flow asphalt mix plant is a part of our production range because a lot of our existing and new customers love it.
Counter flow asphalt mixer is the same traditional hot mix plant used to make quality hot mix asphalt compared to the parallel flow drum mix plants. The process of counter flow or double drum asphalt mixing plant is very much the same except that the process of drying of aggregates is in first drum and mixing of the aggregates is in second drum after the drying process takes place.
The exhauster sucks dust from the aggregates when they enter the first drum. The dust is treated to dry and wet dust collector. The aggregates when moving towards the burner flame are dust free which means less fuel is consumed by the dryer drum to heat the aggregates. Wastage is zero when compared to parallel flow asphalt drum plant.
The position of the dryer burner is on the opposite direction of the flow of aggregates. This allows maximum heating of aggregates as they move towards the burner flame in the entire course of their travel in the first drum.
There is an additional option to weigh the aggregates before they enter the mixing drum and synchronize the data with the inlet of bitumen and lime. This data is of the heated aggregates sans the unwanted dust. So only the required quantity of asphalt and lime is mixed in the second drum to make quality hot mixed asphalt ready to be laid for making road.
The wet dust collector here can be replaced with a bag house filter so as to trap the dry dust as in asphalt batch plants. When bag house is used with single drum plant, the dust sucked by the exhauster has particles of bitumen which calls for frequent replacement of the filter bags of bag house. We have supplied this counter flow asphalt plant in Malaysia and the plant meets local environmental norms laid down for asphalt plants.
We have also supplied mobile asphalt plants in the counterflow design.
The components of asphalt plant are cold feed bins, vibrating screen, charging conveyor with load cell for weighing of aggregates when they are being transferred to the next component drying drum. Drying drum is equipped with burner for efficient heating of aggregates. After the drying drum comes the mixing drum for mixing of heated aggregates with bitumen and lime. Other components that accompany the plant are fuel tank for dryer burner, bitumen tank(s), mineral filler, dry and wet dust collector type pollution control device. A control cabin with PLC or Microprocessor based control panel does the controlling of the asphalt concrete plant in auto and manual mode efficiently. Storage silo options are also available.
The difference in the design compared to the single drum asphalt mixing plant may seem that this plant is just to take extra money compared to asphalt drum mix plant single drum. But by the time you have finished reading this article you will understand the concept behind the plant.