Steam boiler is fired with a coal having the following analysis: Ultimate (%w) Proximate (%w) Carbon, C 60 Moisture 9 Hydrogen, H 14 VM 41 Sulfur, S 0 FC 40 Ash 10 Ash 10 Oxygen, O 16 Total 100 Nitrogen 0 Total 100 17,000 ft3 of wet air is supplied per 80 lbs of coal fired. The wet air is at 750 mm Hg, 60oF and the water vapor in it exerts a partial pressure of 10 mm Hg. The dry refuse from this furnace contains 11.2% FC, 9.3% VCM and 79.5% ash. Because of poor operation, only 80% of the carbon burned forms CO2, the rest forms 20% CO. a. Calculate % excess air b. Complete ORSAT analysis of the flue gas c. The partial pressure of water vapor in the wet flue gas, if the total pressure is 750 mmHg.
Steam boiler is fired with a coal having the following analysis:
| Ultimate (%w) | Proximate (%w) | |||
| Carbon, C |
60 |
Moisture | 9 | |
| Hydrogen, H | 14 | VM | 41 | |
| Sulfur, S | 0 | FC | 40 | |
| Ash | 10 | Ash | 10 | |
| Oxygen, O | 16 | Total | 100 | |
| Nitrogen | 0 | |||
| Total | 100 |
17,000 ft3 of wet air is supplied per 80 lbs of coal fired. The wet air is at
750 mm Hg, 60oF and the water vapor in it exerts a partial pressure of 10 mm Hg. The
dry refuse from this furnace contains 11.2% FC, 9.3% VCM and 79.5% ash. Because of
poor operation, only 80% of the carbon burned forms CO2, the rest forms 20% CO.
a. Calculate % excess air
b. Complete ORSAT analysis of the flue gas
c. The partial pressure of water vapor in the wet flue gas, if the total pressure is 750 mmHg.
d. make an overall material balance between mass of coal, mass of air = mass of stack gas, mass of refuse
e. The percentage of the HHV of coal lost because of unburned combustibles in the refuse
f. The percentage of HHV lost because of unburned combustible in the flue gas
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