ATMOSPHERIC FLUIDIZED-BED COMBUSTION OF HIGH-SULFUR HIGH VOLATILE NE REGION COALS OF INDIA

In order to investigate in situ sulphur absorption by limestone as wel l as combustion characteristics of high volatile high sulphur N.E. Reg ion deals of India in fluidized-bed, steady state experiments were con ducted in a 0.67 sq. meters cross-sectional area fluidized bed combust or (10 T/hr hot water capacity). Flue gas was monitored continuously w ith on-line gas analysis system. Calcium to sulphur molar ratio ranged from 3 to 4, the average bed temperature from 780 to 866 degree centi grade and excess air from 19.2 to 47.4 per cent. It is observed that i t is difficult to maintain bed level at Ca/S molar ratio 3. Optimum su lphur retention temperature is in the range of 830 to 850 degree centi grade. The combustion efficiencies are in the range of 82 to 88 per ce nt and have been found to rise with bed temperature. Heaat transfer co -efficients in fluidization zone ranged from 146 to 215.8 kcal/hr/mete rs square/degree centigrade and in the freeboard from 14.1 to 23.98 kc al/hr/meters square/degree centigrade.