| 摘要 |
<p>PURPOSE:To remove NOx contained in exhaust gas economically and at a high denitration ratio, by addn. of petroleum fuel in a specific ratio of remaining O2 in high-temp. exhaust gas to O2 required for complete combustion of the added petroleum fuel, and by addn. of air for removing material not yet burned into the downstream side, then by addn. of high-temp. exhaust gas. CONSTITUTION:Petroleum fuel is added in such a quantity that the ratio of O2 remaining in high-temp. exhaust gas, which is at 1.000-1,600 deg.C and contains NOx having formed in a furnace 1a of a boiler 1, to O2 required for the complete combustion of the added petroleum fuel such as propane added through a line 2 is 1:0.2-1.2. Considerable portion of the NOx contained in the exhaust gas is converted to N2, and a portion to NH3, HCN etc. At a downstream side, at 700- 1,000 deg.C, air sufficient for removing residual combustible material is added through a line 3. A small portion of NH3, HCN remains unconverted. To remove these cpds, high-temp. exhaust gas at 1,000-1,600 deg.C is added through a line 4 in order to heat the exhaust gas to 900-950 deg.C.</p> |
