GB1277786A - Process and apparatus for roasting solids - Google Patents

Abstract

1277786 Shaft furnaces; charging and discharging SOC D'ETUDES ET DE RECHERCHES SCIENTIFIQUES ET MINIERES 29 July 1969 [30 July 1968 10 July 1969] 38122/69 Heading F4B A shaft furnace for roasting lime or sintering dolomite or magnesite comprises a central shoot 30 through which large material is fed, inlets 34a supplying mixed fuel oil vapours and primary air through flared ports 33a, inlets 34b supplying secondary air through ports 33b and a rotary discharge grate 36 with a central core. The latter and the edges of the grate 36 may be formed with crushing ribs. The shoot 30 is supplied with large material from a rotary hopper disposed thereabove and associated with an outer hopper supplying smaller material to the annular space between the shoot 30 and the furnace wall 31 (Fig. 4). In a modification (Fig. 8) combustion chambers (38) disposed around the furnace shaft have ports (37) opening into said shaft between the ports 33a and the bottom of the shoot 30. Another modification, Fig. 10 has combustion chambers 109 around the shaft with burners 111 and tapering down to narrow slit-like ports 108. Disposed vertically below the ports 108 are recesses 112 in the shaft walls which may be the same width or slightly greater than said ports. The combustion chambers may narrow down suddenly near the ports to create turbulence (Fig. 12).