초록 ▼

A drum mixer having an countercurrent flow drying zone and a parallel flow mixing zone is provided for producing an asphaltic composition. The drum mixer utilizes a heat source located at an intermediate position therein for generating three streams of hot gases. The first stream of hot gases is dir

A drum mixer having an countercurrent flow drying zone and a parallel flow mixing zone is provided for producing an asphaltic composition. The drum mixer utilizes a heat source located at an intermediate position therein for generating three streams of hot gases. The first stream of hot gases is directed towards the receiving end of the drum mixer in a countercurrent direction to the flow virgin aggregate entering the drying zone of the drum mixer. Recycle material is introduced into the drum mixer between the heat source and the discharge end thereof. The recycle material and the heated virgin aggregate are combined within the mixing zone. As both materials travel towards the discharge end of the drum mixer the second stream of hot gases is directed towards the discharge end of the drum mixer in a parallel direction to the flow of the mixing materials for heating said materials. Liquid asphalt is mixed with the virgin aggregate and the recycle material in the mixing zone and the resulting asphaltic product is removed from the drum mixer at the discharge end. As the second stream of hot gases exits the discharge end of the drum, the flow of the second stream of hot gases is reversed creating a third stream of hot gases. The third stream of hot gases is returned to the heat source within the drum for burning hydrocarbon by-products produce during the operation of the drum mixer.

대표청구항 ▼

In a method for continuously producing an asphaltic composition comprising the steps of: introducing a first volume of material into an inclined, rotating drum at a first end to flow generally from the first end to a second end of the drum: creating a flame at an intermediate location in the drum an

In a method for continuously producing an asphaltic composition comprising the steps of: introducing a first volume of material into an inclined, rotating drum at a first end to flow generally from the first end to a second end of the drum: creating a flame at an intermediate location in the drum and directing a first stream of hot gases produced thereby to flow towards the first end of the drum in countercurrent relation to the flow of the first volume of material for heating the first volume of material; introducing a second volume of material into the drum between the flame and the second end of the drum to flow generally towards the second end of the drum; mixing the heated first volume of material with the second volume of material between the flame and the second end of the drum; directing a second stream of hot gases produced by the flame to flow towards the second end of the drum in parallel relation to the flow of the mixing materials for heating the mixing materials; and discharging the asphaltic composition from the second end of the drum.