| 摘要 |
A wet type exhaust gas desulfurization method wherein an exhaust gas discharged from a combustion apparatus, such as a boiler and an absorption liquid are brought into contact with each other to have sulfur oxide in the exhaust gas absorbed in the absorption liquid and neutralize the sulfur oxide-absorbed absorption liquid, characterized in that lime stones of a large grain size are allowed to stay selectively in a position in which the absorption liquid is neutralized, the absorption liquid which contains as main components gypsum produced from the sulfur oxide and water being discharged selectively from the neutralization position. In the neutralization position, an ascending current of the absorption liquid is formed, or an ascending current of air or water is formed with or separately from the ascending current of the absorption liquid, to produce a fluidized bed of lime stone particles, whereby the reactivity of the lime stone is maintained with the scaling of gypsum particles around the lime stones prevented. Thus, even when aluminum and fluorocomponents coexist in the absorption liquid, the desulfurization performance does not substantially lower. Moreover, the cost of power for pulverizing the lime stones can be reduced, and high desulfurizing performance can be attained. A wet-type flue gas desulfurization method and plant making use of a solid desulfurizing agent in which exhaust gas exhausted from a combustion equipment such as boilers is brought into contact with absorbing liquid to absorb sulfur oxide from the exhaust gas to the absorbing liquid followed by neutralization of the absorbing liquid containing the sulfur oxide thus absorbed, which comprises selectively leaving the solid desulfurizing agent in an absorbing liquid neutralizing zone and selectively draining the absorbing liquid containing water as a main constituent and solid products formed by the sulfur oxide from said neutralizing zone. In the neutralizing zone, an upward flow of the absorbing liquid is generated or, together with said upward flow or independently therefrom, an upward flow of air or water to form a fluidized bed of limestone particles, thereby preventing scaling of gypsum particles around limestone and keeping reactivity of limestone. According to the present invention, coexistence of Al and F in the absorbing liquid seldom deteriorates the desulfurizing performance. Further, it is possible to reduce a power cost required to grind limestone and to achieve higher desulfurizing performance. <IMAGE>
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