The Rotary Dross Cooling System for white and black aluminum dross guarantees high metal recovery and has a processing capacity of up to 12'000 kg per hour. The CETAG rotary cooler design is based on the principle of indirect cooling of the metal.
The dross is skimmed into the CETAG dross pot / drain pan assembly which allows for maximum drainage of free liquid metal. This free run can be charged directly back into the furnace. The dross pots are located onto the charging mechanism by forklift truck. The charging system lifts and tilts the dross pot discharging the dross into the charging mechanism. The hot dross is then fed into a rotary drum in a controlled manner.
The drum is externally cooled with water to ensure efficient cooling.
The cooling drum is fabricated from structural steel plate with welding procedures to pressure vessel standards. Flights and helical scrolls are welded inside the drum. The location and angle of the flights are designed to give the desired longitudinal movement and retention time of material for optimum cooling while the scrolls are discharge the material.
A charge of hot dross is processed through the system and cooled to a temperature of less than 100 °C in about 15 min. Because the material is brought quickly below the oxidation range, the percentage of aluminum in the cooled dross will be approximately the same as when it was skimmed from the furnace. The system discharges the cooled material through a variety of screens and sorting devices depending upon the customer requirements for segregation by alloy and / or size.
The design of the equipment takes the severe and aggressive operation conditions of an aluminum casthouse fully into consideration.
The main principle of the Rotary Dross Cooling System is providing good heat transfer to the cooling medium. A key factor in the design is to ensure that the outer surface of the cooling drum is covered with water at all times. This is achieved by the unique three way cooling system.
A vapour hood is installed above the water tank to retain water vapour and to eliminate any water spillage from the system.
The dust created during the charging and discharging of the Rotary Dross Cooler is pulled out by exhaust ducts connected to a dust treatment system.
The proven Rotary Dross Cooling System is designed to rapidly cool aluminum dross from the thermiting range to an easily handleable cool material.
Utilization of the three way cooling method is unique to CETAG equipment and provides the industry’s most rapid rate of dross cooling, as well as a very important safety features.