The MBHE BioBurn grate is a flat-surface pinhole grate, which is slightly inclined and specifically designed for the combustion of biomass.
The fuels that can be successfully burnt in the spreader firing mode on the BioBurn grate include:
- Bagasse, which is the residue of sugar cane used in the sugar industry
- Biomass in the form of hogged wood waste, pelletised wood, woodchips, wood shavings, sawdust and wood trash from the forest product industry
- Vegetable refuse such as rice hulls, coffee grounds, corn cobs and straw, as discarded by the agricultural and food industries
The fuel is introduced into the lower furnace by pneumatic spreaders, where the lighter fractions burn in suspension and the heavier fractions fall down and burn on the grate.
The grate system, which has cooled floor tube supports, can tolerate under-grate air temperatures up to 300°C, burning fuels with moisture content ranging from very dry to 55%-60% H2O by weight.
The grate is constructed from high-quality castings supported on a tube grid, either water-cooled or air-cooled. The grate tiles are attached to the floor tubes of the furnace, water-cooled and forming part of the boiler circulating system. Alternatively, the grate tiles are attached to the air-cooled furnace floor tubes, forming part of the boiler over-fire air system.
