| 摘要 |
<p>PURPOSE:To prevent a generation of scales such as CaSO3, CaCO3 etc. by maintaining pH of a washing-liq. containing Mg components to the fixed value, by joining a part of washing-liq., which is oxidized previously, to the main circulating washing-liq. CONSTITUTION:An SO2-containing waste gas 11 is fed into a scrubbing tower 12 to make the gas-liq. contact with a circulating washing-liq. 13, and to discharge desulfurized waste gas into the atmosphere. On the other hand, a part of washing-liq. 14 containing MgSO3 etc. is sent from a washing-liq. circulating tank 16 to an oxidation tank 18, and MgSO3, and CaSO3 contained in the liq. 14 are oxidized into MgSO4 and CaSO4 respectively by an O2-containing gas 19 inducted into an oxidation tank 18. A part of oxidized liq. 20 is discharged out of the system, and the remains, joining with the liq. in the tank 16, is recirculated to the tower 12 as a circulating washing-liq. 13. At that time, an MgOH slurry 22 is added into the tanks 16 and 18, from a desulfurizing-agent supplementing tank 2, and is controlled so as to put the pH of the liq. 13 in 4.6-5.9pH range.</p> |
