(C) To compute the loss in the heat carried away by dry chimney gases per pound of coal the weight of such gases must be first determined. This weight per pound of coal is:
| ( | | 11CO2 + 8O + 7(CO + N) | | ––––––––––––––––––––––––––––––––––––––––––– | | 3(CO2+CO) |
| ) | C |
|
[Pg 263]
where CO2, O, CO and H are the percentage by volume as determined by the flue gas analysis and C is the percentage by weight of carbon in the dry fuel. Hence the weight of gas per pound of coal will be,
| ( | | 11 × 14.33 + 8 × 4.54 + 7(0.11 + 81.02) | | –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––– | | 3(14.33 + 0.11) |
| ) | × 78.57 | = | 13.7 pounds. |
|
Therefore the loss of heat in the dry gases carried up the chimney =
| 13.7 × 0.24(480 - 81) | = | 1311 B. t. u., | | | = | 9.22 per cent. |
|
(D) The loss due to incomplete combustion as evidenced by the presence of CO in the flue gas analysis is:
| 0.11 | | ––––––––––––––––––––– | | 14.33 + 0.11 |
| × 78.57 × 10,150 | = | 61. B. t. u., | | | | = | .43 per cent. |
|
(E) The loss due to unconsumed carbon in the ash: