| 摘要 |
PURPOSE:To make it possible to adapt the titled method to SO3-monitoring and the corrosion counter-measure of a gas heater in a plant, by measuring the optical transparency of exhaust gas in such a region that the temp. of exhaust gas is 100 deg.C or less while converting the measured value into an SO3-concn. CONSTITUTION:The gas containing fly ash, SO2, SO2 or SO3 generated in a boiler 1 enters an electric dust collector 3 at about 100-200 deg.C while cooled by an air preheater 2 to remove dust therein while the dust removed gas is cooled to about 100 deg.C or less by a gas-gas heater 4 and humidified and cooled to a saturation temp. by the cooling tower 5 of a desulfurization apparatus. In the next step, the treated gas is supplied to the absorbing tower 6 of the desulfurization apparatus to absorb SO2 therein and the clean gas is exhausted from a chimney 7 while again heated by the gas-gas heater 4. Apparatuses each for measuring the transparency of exhaust gas are provided to the (a)-part between the gas-gas heater 4 and the cooling tower 5, the (b)-part between the cooling tower 5 and the absorbing tower 6 and the (c)-part between the absorbing tower 6 and the gas-gas heater 4 and the optical transparency of the exhaust gas is measured to detect the SO3-concn. in the exhaust gas. |
