In a global landscape where environmental sustainability has become essential, a key question arises: what will happen in the coming years if bottom ash handling in Pulverised Coal-Fired (PCF) power plants continues to depend on massive volumes of water for cooling and conveying?

Today, thermal power plants using Pulverised Coal-Fired boilers face stringent environmental regulations, water scarcity and ash disposal challenges. In this scenario, conventional Wet Bottom Ash Handling Systems (WBAHS) reveal obvious limitations because high water consumption is no longer compatible with modern industrial policies, and the latent risk of contaminated leakages severely compromises plant compliance.

The definitive solution to these operational challenges is the wet-to-dry bottom ash handling system retrofit which completely eliminates water consumption. In this context, the MAC® (Magaldi Ash Cooler) system, developed and patented by Magaldi in the early 1980s, provides a clean, reliable and efficient alternative option for PCF boilers, optimising both environmental compliance and boiler efficiency.

Officially recognised by the European Union as the “Best Available Technology” (BAT), the MAC® system provides dry extraction, air cooling and mechanical handling of bottom ash from PCF boilers of any size (from 15 up to 1,050 MW).

Ash cooling is carried out by ambient air, naturally drawn into the system by the negative pressure of the furnace. This air recovers a significant amount of energy in the form of:

• Ash sensible heat;
• Chemical energy from unburnt carbon particles;
• Radiation flux passing through the boiler throat.

The mechanical handling of bottom ash is managed by the Superbelt®. This damage-tolerant stainless-steel conveyor belt combines exceptional tensile strength with resistance to extreme temperatures and heavy impacts, preventing sudden system failures or forced boiler shutdowns that may be associated with conventional WBAHS.

More than 250 certified MAC® units operate worldwide, including in countries like India, South Korea, Mongolia, China, Bangladesh, Japan, the Philippines and Taiwan. Thanks to the use of cooling air that participates in coal combustion as secondary air, the MAC® system recovers up to 90% of boiler heat loss compared to a conventional WBAHS. Consequently, it improves boiler efficiency by a factor in the range of 0.1% to 0.6%, calculated within the framework of ASME PTC4-2013.

Visit Magaldi website for more information: https://www.magaldi.com/en