17 - Classification of Furnaces

Abstract

This chapter focuses on classification of furnaces. Furnaces can be grouped by purpose, by mode of firing, by shape, or by the method of charging. The chapter discusses three major classes of metallurgical furnace, the crucible furnace, the hearth furnace, and the shaft furnace. Crucible furnaces are used in foundries for melting small batches of ferrous and nonferrous metals. Hearth furnaces include a wide range of fixed, tilting, and rotating furnaces and kilns fired with all fuels, and used for roasting, melting, and reheating. Shaft furnaces are used for melting, smelting, and calcining or roasting. In the production of gas from coal and in a few extraction processes, the reactions leading to a gaseous product are carried out in a retort. Converters are used in steelmaking, in copper production, and to a limited extent, in other nonferrous processes. There are other types of furnaces that include suspension roasting, soaking pits, forced air combustion furnaces, and salt baths. A furnace for boiling water is usually called a boiler and basically there are three types of boiler.