| 摘要 |
<p>PROBLEM TO BE SOLVED: To decrease the volume of a waste water discharging section and to reduce the use of ammonia by providing a vaporizer for vaporizing ammonia contained in a desulfurization waste water fed to the waste water discharging section from a desulfurization apparatus and re-injecting to the upstream side of an electric dust collector as ammonia gas. SOLUTION: The waste gas discharged from the boiler 1 is successively passed through a denitrification equipment 2, an air preheater 3, the electric dust collector 4 and the desulfurization apparatus 5 and discharged from a chimney stack 6. When the waste gas discharged from the boiler 1 contains SO3 , SO3 is converted to ammonium sulfate to be collected with the smoke and soot and removed by injecting ammonia to the upstream side of the electric dust collector 4. In such a case, a part of the desulfurization waste water is introduced into the vaporizer 8 and heated by an auxiliary steam to vaporize ammonia contained in the desulfurization waste water. The vaporized ammonia is re-injected to the upstream side of the electric dust collector 4. The remaining desulfurization waste water is biologically treated in the waste water discharging section 7 to be denitrificated.</p> |
