METHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL

**Definition:** This place covers:

General function-oriented aspects of methods and apparatus for combustion of solid fuel wherein the main body of fuel is either

and wherein the combustion does not involve liquid or gaseous fuels, or pulverulent fuel burned in suspension.

The solid fuel can be in the form of lumps or pieces, e.g. coal, briquettes or firewood, or pulverulent or granulated, e.g. coal powder, wood pellets or wood chips.

**Limiting references (this place does not cover):** - Combustion of fuels that are solid at room temperatures, but burned in melted form, e.g. candle wax -> C11C5/00 , F23C , F23D - Combustion of solid fuel suspended in a stream of air, e.g. combustion in fluidised beds or combustion of pulverised fuel using burners where the fuel is transported into the combustion chamber by an air stream -> F23C , F23D1/00 - Combustion of solid fuel suspended in a liquid, e.g. combustion of coal-water slurry -> F23C , F23D - Combustion of both solid fuel and fluent fuel, simultaneously or alternately -> F23C1/00 , F23D17/00

**Glossary:** - Air: a mixture of gases containing free oxygen and able to promote or support combustion - Primary air: air supplied to the burning fuel in order to liberate combustible gases - Secondary air: air supplied to the combustible gases liberated by the primary air in order to complete their combustion. The term "secondary air" covers "tertiary air" etc. - Ash: means any solid combustion residues, for example remaining in the fuel bed or suspended in the flue gases - Burner: a device by which fluid fuel or solid fuel suspended in air is passed to a combustion space where it burns to produce a self-supporting flame - Combustion: means the direct combination of oxygen gas, e.g. in air, and a burnable substance - Combustion chamber: a chamber in which fuel is burned to establish a self-supporting fire or flame and which surrounds that fire or flame - Combustion zone: the part of the apparatus where the reaction takes place between air and fuel - Firebridge: a low wall separating the fuel bed from adjacent flue gas passages in apparatus for combustion of solid fuel, for example in reverberatory furnaces or fire-tube boilers - Flue gases: any gaseous products of combustion - Grate: a perforated surface, e.g. a grid, which supports or delimits a bed of burning fuel and serves to supply primary air