Thermal energy is collected from the liquid product streams using copper cooled components that can be either rigidly fixed in a cascading arrangement or a rotating/moving device that transports the slag and metal products to a discharge point, while simultaneously cooling and solidifying them.
The copper components are cooled by a thermal collector fluid to maintain mechanical integrity while cooling the liquid slag or metal. The heated thermal medium is used to evaporate a working fluid to drive an Organic Rankine Cycle which in turn generates electrical power. The cooled thermal medium returned from the Rankine Cycle is recycled in a closed system to the copper components for re-heating during tapping.
Fixed copper cooled components are used in casting bays utilizing layer casting or ingot casting. The fixed copper cooler pad is placed within the sand/forming mould and the metal/slag is tapped onto it. Heat is extracted from the liquid metal/slag by the copper cooler pad and transferred to the thermal medium.
The rotating/moving copper cooled components are used where tapping is onto a conveyor or a rotating disc. The disc has a copper pad located on top of the disc onto which metal is tapped. The copper pads transfers the heat to the thermal oil to cool and solidify the metal/slag. Blades located on the disc removes the cooled metal from the rotating disc.
The conveyor consists of copper pads located on a moving steel belt. The metal or slag is tapped onto the copper pads for cooling and discharged at the end of the conveyor.
Advantages of the system include:
- Electricity production from a thermal heat source which is otherwise lost heat.
- Reduction of metal fines that will be generated during crushing and screening.
- Reduction of water used for cooling of metal and slag.
- Reduction of casting bay area.
- Clean product compared to casting beds.