Furnace traveling grate

The traveling-grate furnace requires less labor, increases the output per unit of grate area, and produces more uniform product than the WetheriU. furnaces. The traveling grate is an endless chain of cast-iron bars, driven by sprockets, which traverses a firebrick chamber. Anthracite briquettes are fed to a depth of ca 15 cm. After ignition by the previous charge, the coal briquettes are covered by 15—16.5 cm of ore/coal briquettes. The latter are dried with waste heat from the furnace. Zinc vapor evolves and bums in a combustion chamber and the spent clinker faUs into containers for removal (24,25). 

The roasting process mostly applied to sulfidic sources is carried out in appliances of different types with different design features. Without describing their features and constructional details, it may simply be mentioned here that some of the widely acclaimed roasting units are traveling grate furnaces, multiple hearth furnace, rotary kilns, and fluid-ized-bed roasters. 

Fig. 4.14. Traveling grate furnace for roasting, sintering, or pelletizing ores. The ignition arch or hood may be fired with conventional type A flames or flat type E flames (shown, see fig. 6.2.)...

Heat hardening of green iron-ore pellets is accomplished in a vertical shaft furnace, a traveling-grate machine, or a grate-plus-ldln combination (see Ball et al., op. cit.). 

This is a very versatile stoker common in shell boilers and is used with modification in watertube boilers as the traveling-grate stoker. In shell boilers, the air supply is via forced- and induced-draft fans in combination with a balanced or slightly negative condition in the furnace. 

The pot furnace was constructed so that the radiant heat flux, which would prevail at the top of the fuel bed in a traveling grate stoker or incinerator, could be simulated under batch conditions. The burning rates could be determined by measuring the weight loss of the fuel bed as a function of time. The pot was constructed in two sections (Figure 1)- the overbed section (combustion system) and the fuel bed section (conversion system). Secondary air (overfire air) was supplied at a number of... 

Pelletizing (cf. tumbling agglomeration ) Green balls or pellets of ore or minerals are hardened by heat treatment with attendant loss of moisture and volatile matter. Pellet induration, pellet firing Travelling grate, rotary kiln, vertical shaft furnace... 

Fig. 9.29 Schematic representation of the three most common heat induration (sintering) furnaces for iron ore pellets and sketches depicting the corresponding plants, (a) Shaft furnace, (b) straight (travelling) grate, (c) Grate-Kiln [B.42],...

Fig. 6.8-11 Diagrams of the three major furnace types used for the hardening of iron ore pellets a) shaft, b) traveling grate, c) grate-kiln D, Drying F, firing (sintering) C, cooling...

Fig. 6.8-17 I sometric drawings of the three major iron ore pelletizing processes [B.48, B.97], a) Balling drum circuits with shaft furnaces, b) Balling drum circuits with straight travelling grate machine, c) Balling drum circuit(s) or balling pan(s) with grate-kiln hardening system...

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