Dry Bottom Ash Handling in PCF Power Plants burning high-ash content coals
SuperMAC® - Super Magaldi Ash Cooler

The SuperMAC® is a patented system for “dry” extraction, enhanced air cooling and mechanical handling of bottom ash from coal-fired boilers, burning high ash content coals (over 20÷30%, like Indian ones) or other low rank coals.
The SuperMAC® system is an improvement of the MAC® (Magaldi Ash Cooler) system, the world’s leading “dry” bottom ash handling system for utility and industrial boilers burning low-medium ash content coals. It is designed with further cooling capabilities and special system configuration to effectively cool down bottom ash, limiting cooling air generally in the range 1.0÷1.5% of the combustion air rate.
The SuperMAC® system’s very reliable operation is ensured by its construction and the use of the Magaldi Superbelt® which allows safe receipt and conveyance of extremely hot, abrasive and dusty ashes, even if containing very large lumps. High temperatures and tear issues are solved due to the patented method of connecting the pans to the mesh belt, which allows all elements free to expand in any direction.
Ash cooling is carried out by air that enters the system through accurately sized inlet valves located along the conveyors. A certain amount of cooling air is forced to cross the belt and the ash layer, gaining intimate contact between the air and the ash particles thus maximizing the cooling process.
The SuperMAC® system improves boiler efficiency more than the standard configuration of the MAC® system, thanks to a higher ash to cooling air ratio and a more effective heat exchange. Boiler efficiency improvement is calculated within the framework of ASME PTC4-2013.