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Last update: 06/03/2020

Horizontal grate


The MARTIN horizontal grate consists of alternating rows of fixed and moving grate bars. Neighbouring moving grate bar rows make a counter movement, thus effectively transporting and mixing the waste to ensure good burnout.


The horizontal grate is of modular design. The length of each module is fixed but the width may vary according to specific requirements. Each module has its own drive and supply of underfire air, both of which can be controlled separately. A typical grate configuration consists of 3 modules in the waste flow direction. There may be between 1 and 3 runs depending on requirements.


The combustion properties of municipal waste have changed over time as a result of, for example, separate collection or presorting policies, thus necessitating the development of water-cooled grate bars to achieve acceptable service lives. An added benefit of this system is that underfire air is no longer needed to cool the grate bars and is controlled only as and when required by the combustion process. The heat dissipated by means of the water-cooling system can be returned in full to the process.

Furnace geometry, the arrangement of the overfire air nozzles, and the choice of refractory material are crucial to ensure good burnout of the bottom ash and flue gas.



Image Image
 Water-cooled grate bar  Motion of the grate bars


 Grate bar configuration  Furnace geometry