Determining the focus
Boiler design and calculation: furnace and circulation

The essential role of the hearth is to ensure combustion under the right conditions, i.e. :

• with safety, which implies flame stability and sufficiently accurate detection of extinguishment to avoid the risk of explosion by re-ignition;

• with good efficiency, i.e. with minimum unburnt gas and solids, and minimum excess air;

• with a minimum of maintenance, hence the need to reduce refractory parts, which are always more fragile and more susceptible to ash sticking than metal parts;

• with the possibility of using several fuels either separately or together.

In addition to this main role, which in the past was reserved for fireboxes lined with refractory bricks, then progressively lined...