Solid Fuels

Solid Fuels. Introduction. Solid fuel embraces a wide variety of combustibles. In thermal terms 90% of the known hydrocarbon fuel deposits are formed by coal. It is usual to consider coals in terms of their rank in general. Coal is a sedimentary rock of vegetable origin. The ranking sequence. Coal was the fuel which fired the Industrial Revolution. Recent developments in. Coal Classification. As the rank. The moisture in. Coals are also analyzed in terms of their elemental constituents. Coal Properties. There are a. Calorific value. The ranking of a coal is not necessarily related to its calorific value. Ash Fusion Temperature. Sulfur Content. Many deep-mined coals have a fairly high sulfur content. Coal Combustion. Coal combustion is a two-phase process and the objective of the burner is. Pulverized Fuel. The coal is ground to a very fine size (about. The fuel is injected in the form of a conical spray. Although the fluidization requires more fan power than the conventional grate combustions (Figs. High rates. Grate Combustion. The volatiles will then rise through the bed. As the air enters the fuel bed from below. The effect of. Underfeed Stoker Next. The de-ashing of underfeed stokers is generally a manual process. Chain Grate Stoker. A diagram of a chain grate boiler is shown in Fig. The fuel for. Coal Storage and Handling. Solid fuels are.