| 摘要 |
<p>1,153,710. Apparatus for indurating pellets. ARTHUR G. MeKEE & CO. 20 May, 1966 [22 June, 1965], No. 60178/68. Divided out of 1,124,127. Heading F4B. Apparatus for making pellets from finely divided oxidic Fe material comprises a travelling grate on which green balls of the material are dried by hot gasses passing through the grate, a rotary kiln into which the balls are discharged from the grate and through which hot gases are passed, and a cooler in which the hardened balls (pellets) are cooled in the absence of air, the exhaust gases from the kiln either being passed directly to dry the balls on the grate after dust removal, or being passed in heat exchange with the gas supplied to the grate and then treated for dust removal. The balls may be heated at 250-800‹ F. on the grate, hot air being drawn from above, and then discharged into the kiln together with particles of coal or coke. Combustion gases from a gas or fuel oil fired burner may pass in countercurrent in the kiln and maintain a temperature of 1600-2500‹ F. The pellets may be cooled to below 300‹ F. in a rotary water jacketed cooler in an atmosphere containing CO 2 , CO, N 2 and inert gases carried over from the kiln. If the kiln exhaust gases are recycled directly they may be tempered with exhaust air from the drying zone; if they are passed in heat exchange with air, some of the air may be used as combustion air.</p> |
