Magaldi Group - Hot Bulk Material Handling and Dry Bottom Ash Extraction Systems

The Magaldi Group, founded in 1929, is a recognized world leader in hot bulk material handling and dry bottom ash extraction from coal fired boilers. The Magaldi material handling technologies, protected by several international patents, focus on preserving the environment, saving the energy and enhancing dependability.

Today, Magaldi serves a wide variety of customers in several industrial sectors, including power and coal fired boilers, cement, lime and gypsum, foundries, steel mills and other metallurgic industries.

Ash coolers

The patented Magaldi ash cooler (MAC) is a unique system for the dry extraction, cooling and handling of bottom ash from pulverized coal-fired boilers. With more than 126 systems worldwide, on boilers up to 900MWe for a total power of 45,000MWe, the MAC is the world’s leading dry bottom ash handling system for utility boilers.

The success of the MAC system can be attributed to the following benefits:

• Elimination of water usage in cooling and conveying bottom ash
• Reduction of carbon content in bottom ash
• Recovery of energy from ash and refund to the boiler
• Potential sale of dry, low carbon ash
• Reduction of operational and maintenance costs compared to conventional wet systems

Ash recycling system

In order to reduce the environmental impacts of bottom ash dumping and make coal-ash usable in cements or concretes, Magaldi has patented and developed a system able to extract, cool and recycle in the combustion chamber, the ash produced by solid fuel fired boilers.

The new Magaldi ash recycling (MAR) system combines the benefits of the MAC system and has the following additional features:

• Conversion of bottom ash into saleable fly ash
• Elimination of costs associated with bottom ash disposal
• Reduction of loss on ignition (LOI) content in fly ash due to dilution effect of recycled bottom ash
• Wear rate reduction for the bottom ash milling system and benefits in terms of spare parts savings and lower maintenance costs
• Production of fly ash in compliance with international standards; in the EU, these are EN 197-1:2000/A3:2007 for cement and EN 450-1:2005/A1:2007 for concrete (LOI = 5% and fineness = 40% by mass as oversized particles on a 0.045mm mesh sieve when wet sieved)
• Environment protection: decrease of CO2 emissions when mixing fly ash with cement in the concrete production

Mill rejects system

The Magaldi Mill Rejects System (MRS) is a patented steel-belt conveying system fully automatic designed to dry handle mill rejects from coal mills to a storage silo based upon the well-proven and dependable Magaldi Superbelt.

As no water is required in the MRS operations, any environmental problems associated with wet systems are avoided, as far as plugging problems which may occur either in sluice or pneumatic conveying systems. The features of the proven Magaldi Superbelt allow the MRS to handle any quantity of mill rejects with a fraction of energy required by traditional systems.

Bottom ash handling for high ash content applications

The SuperMAC system is a patented technology for bottom ash handling developed by Magaldi for high ash content coal applications. In case of high ash content coals, traditional wet systems require a very large amount of water for cooling bottom ash and, at the same time, can determine a boiler's decreasing efficiency.

The SuperMAC system safely handles and cools the bottom ash quantities produced by boilers fired with high ash content coals and at the same time dramatically reduces the losses at the bottom of the boiler in terms of losses of bottom ash enthalpy, losses of unburned carbon in bottom ash and losses of radiative energy leaving the boiler through to the water pit.

Dry handling of bed ash for boilers

The patented FLUIMAC system is an innovative system for the dry handling of bed ash from fluidized bed combustion (FBC) boilers. The FLUIMAC system is characterized by low operation and maintenance requirements, long-life equipment and parts, and no usage of water in the ash processing. In addition, with the FLUIMAC system, it is possible to increase the boiler efficiency using heat recovery from the ash.

Economizer ash extractor

Another successful application of Magaldi ECOMAG has been achieved with economizer ash handling, where an automatic sequence of extraction, conveying and cooling is performed by a steel-belt conveyor in the most reliable way. Problems from bridging or plugging in the eco hoppers are eliminated, while ensuring low O&M costs and long-life equipment without the use of water.

Bulk materials handling

Dependable handling of bulk materials is important to ensure the highest productivity in many industries. It is difficult for traditional conveyors to withstand the high temperature, the heavy weight, the abrasiveness or the sharp edges of diverse materials. The Magaldi Superbelt conveyor (in its different configurations) is the dependable and environmentally friendly solution for these problems.