Flue gas treatment apparatus and flue gas treatment method

摘要

A flue gas treatment apparatus for removing sulfur contents contained in combustion flue gas, includes a treatment agent feeder to feed a treatment agent into a flue through which the combustion flue gas flows, a cooler to cool the combustion flue gas to which the treatment agent has been fed and condense SO3 components in the combustion flue gas, an electric dust collection apparatus provided in the flue, a desulfurization apparatus based on a lime-gypsum process, and a circulation line for feeding a portion of the dust particles recovered by the electric dust collection apparatus into the flue that is provided on an upstream side of the cooler in the direction of flow of the flue gas for circulated use thereof as the treatment agent.

主权项

1. A flue gas treatment apparatus for removing sulfur contents contained in combustion flue gas, comprising:
treatment agent feeding means for feeding a treatment agent into a flue through which the combustion flue gas flows; temperature decreasing means for cooling the combustion flue gas to which the treatment agent has been fed to condense SO3 components in the combustion flue gas; an electric dust collection apparatus provided in a flue arranged on a downstream side of the temperature decreasing means in a direction of flow of flue gas; a desulfurization apparatus based on a lime-gypsum process, provided downstream of the electric dust collection apparatus in a direction of flow of the flue gas; and circulation means for feeding a portion of dust particles recovered by the electric dust collection apparatus into a flue arranged upstream of the temperature decreasing means in the direction of flow of the flue gas for circulated use of the portion of the dust particles as the treatment agent; and control means for controlling an amount of the dust particles to be disposed of, an amount of the dust particles to be circulated for reuse, and an amount of the treatment agent to be additionally fed so as to satisfy, at a timing (t), the following expressions (I):
D(t)=Z(t)×Y/(X0+Y)×K1(t)R(SO3)(t)=Z(t)−D(t)X(SO3)(t)=X0−R(SO3)(t)  (I) wherein D(t) denotes an amount of the dust particles to be disposed of, of the dust particles recovered by the electric dust collection apparatus, Z(t) denotes the total amount of the dust particles recovered by the electric dust collection apparatus, X0 denotes an amount of the treatment agent to be fed before circulation is started, Y denotes an amount of SO3 to be removed from the combustion flue gas, R(SO3)(t) denotes an amount of the dust particles to be circulated by the circulation means for reuse, X(SO3)(t) denotes an amount of the treatment agent to be additionally fed, and K1(t) denotes a correction amount of the dust particles to be disposed of.