Dry Bottom Ash Handling in PCF Power Plants
MAC® - Magaldi Ash Cooler

The MAC® (Magaldi Ash Cooler) is a unique system for dry extraction, air cooling and mechanical handling of bottom ash from pulverized coal-fired boilers.
With hundreds of installations worldwide since the 1980’s, the MAC® is the world’s leading dry bottom ash handling system for utility and industrial boilers of any size and burning any kind of solid fuel.
Proven by millions of trouble-free operating hours, the reliability of the MAC® is guaranteed by the “multi-link” design of the Magaldi Superbelt® - core technology of the MAC® system - realised according to a “damage-tolerant” approach ensuring safe collection and conveyance of extremely hot, abrasive and dusty ash, even if containing very large lumps.
High temperatures and tear issues are solved thanks to the patented method of connecting the pans to the mesh belt, which leaves all elements free to expand in any direction.
In the MAC® system, ash cooling is carried out by ambient air, naturally drawn into the system by the negative pressure of the furnace. That air recovers a significant amount of energy in the form of ash sensible heat, ash chemical energy from unburnt particles and boiler radiation flux through the throat. The dry cooling process has been proven to have no negative effects on the main combustion.
Compared to conventional wet systems, the MAC® can improve boiler efficiency by a factor in the range 0.1÷0.6%, depending on the coal properties and ash rates, calculated within the framework of ASME PTC4-2013.