Working Principle of an Asphalt Drum Mix Plant
How cold, damp aggregate becomes hot mix asphalt in one continuous flow through a Vinayak drum mix plant, explained in seven steps.
The principle in one line
Aggregate and burner gas flow through one inclined, rotating drum: the front zone dries and heats the stone, the rear zone coats it with bitumen and filler, and hot mix leaves continuously. New to these plants? Start with what an asphalt drum mix plant is.
How it works, step by step
Cold feeding
Loaders fill four cold bins with different aggregate sizes. Each bin feeds its share onto a gathering conveyor in the ratio set by the mix design.
Weighing
A continuous belt weigher with load cell measures the combined aggregate flow and sends it to the control panel, which sets bitumen dosing to match.
Screening
A vibratory screen removes oversize stones and lumps before the material reaches the drum.
Drying and heating
The slinger conveyor throws aggregate into the drum. Flights lift and drop it through the burner's hot gas stream, driving off moisture and raising its temperature.
Bitumen coating
Further down the drum, hot bitumen from the insulated tank and mineral filler from the filler unit are added. The rotating drum tumbles them together into a homogeneous mix.
Dust control
An exhauster pulls drum gases through a multi-clone dust collector, plus a wet scrubber or bag house if fitted, before releasing them.
Load-out
Hot mix discharges onto a heat-resistant load-out conveyor and into a hopper with a hydraulic gate, which fills tippers for the paving site.
Keep reading
Frequently asked questions
Why is it called a drum mix plant?
Because both drying and mixing take place in the same rotating drum. Aggregate is heated in the front part of the drum and coated with bitumen in the rear part.
What temperature does hot mix leave the plant at?
Discharge temperature is set by the mix design and bitumen grade specified for the project. The burner and feed rate are adjusted from the control panel to hold that temperature.
How is bitumen quantity controlled?
The belt weigher measures aggregate flow continuously and the control panel meters bitumen in proportion, so the binder content follows the job mix formula as feed rate changes.
Planning a road project? Get a plant sized to it.
Share your required output, mix type and site location. The Vinayak team will recommend a model and send a quotation.
