| 摘要 |
PURPOSE:To accomplish the subject dechlorination without causing cooking efficiency decline by treating with an electrostatic precipitator the exhaust gas produced by combustion of kraft pulp cooking waste liquor followed by spraying water into the exhaust gas to wash the gas to effect dechlorination to prevent the equipment from corrosion followed by desulfurization through a conventional process. CONSTITUTION:In recovering chemicals by combustion of kraft pulp cooking waste liquor, black liquor (a) as the cooking waste liquor is combusted in a recovering boiler 1, the resulting smelt (b) is fed to a dissolver 2 where the chemical liquor is regenerated, and the exhaust gas c produced by the above combustion is treated in an electrostatic precipitator 3. The resulting exhaust gas (c) is sent to a dechlorination column 4 where water is sprayed into the gas to wash the gas; in this case, part of the effluent is used as recycled water, through circulation with a pump together with newly replenished fresh water, thus carrying out dechlorination (the chlorine ion is separated and removed in the form of hydrogen chloride). Then, the exhaust gas dechlorinated is brought to a desulfurization column 5 where the gas is desulfurized through a conventional process, thus accomplishing the objective dechlorination without causing cooking efficiency decline with the equipment prevented from corrosion. |
