| 摘要 |
<p>PURPOSE:To maintain the flow velocity of waste gas incorporated in a denitration apparatus to the prescribed value or more to secure the soundness of the apparatus by circulating one part of the waste gas of an outlet side of the denitration apparatus to an inlet side of it in the period of light load of a furnace. CONSTITUTION:When the combustion of a boiler furnace 4 is led to light load operation, one part of the waste gas 5 of the outlet side of a denitration apparatus 6 is circulated and fed to an inlet side of the apparatus 6 via a takeout pipe 9 for the circulated gas, a waste gas mixing fan 8 and a feed pipe 10 for the circulated gas by opening the dampers 11, 14. Thereby the flow velocity of the waste gas passing through the apparatus 6 is made higher than the prescribed value to secure the soundness of the apparatus 6. In this case, when the mixing of waste gas into air 2 for combustion is unnecessary, the dampers 12, 15 are closed and when it is necessary, the divergence of the dampers 12, 15 is regulated in accordance with the necessary amount of the waste gas to be mixed.</p> |
