Ignition arch

In the continuous sintering process, a mixture of ore dust and coke breeze or anthracite coal is delivered to a traveling grate in a continuous bed about 18" (0.46 m) deep passing under an ignition arch or ignition hood of burners for induration. (See fig. 4.14.)... 

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.)...

Ignition Arch. A refractory arch in a boiler furnace fitted with a mechanical grate its purpose is to assist the ignition of the fuel as the latter moves under the hot brickwork. 

Fixed orSlowlj M-OvingFeds. For fuel-bed burning on a grate, a distillation effect occurs. The result is that hquid components which are formed volatilize before combustion temperatures are reached cracking may also occur. The ignition of coal in a bed is almost entirely by radiation from hot refractory arches and from the flame burning of volatiles. In fixed beds, the radiant heat above the bed can only penetrate a short distance into the bed. 

Oxide, OjY2, yttria White powder, body-centered cubic structure d 5.03. Obtained by igniting yttrium or its salts. Sol in dil acids readily absorbs ammonia from the air displaces ammonia from ammonium salts, LD in rats 500 mg/kg i.p., Cochran et ai. Arch. Ind. Hyg. Qccup. Med. 1, 637 (1950),... 

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