DRY EXHAUST GAS TREATMENT METHOD

摘要

PURPOSE:To simultaneously perform desulfurization and denitration and to prevent the formation of sulfite by supplying a particulate material having absorbed sulfur oxide and nitrogen oxide collected in a dry dust collecting process into exhaust gas and forming a part of the collected particulate material into a slurry to spray the slurry into exhaust gas. CONSTITUTION:Fly ash is supplied to a slurrying process 101 from a supply passage 102 and calcium oxide or slaked lime is supplied to said process from a supply passage 103 and a particulate material collected from exhaust gas is added to the process 101 from a conduit 123 along with water to prepare a slurry. This slurry is conditioned and aged to obtain an adsorbent which is, in turn, sprayed into a drying chamber 113 from a spray nozzle 114. By this constitution, SOx in exhaust gas is mainly removed and a part of a solid reaction product is recovered. The exhaust gas accompanied by the remainder of the reaction product and the unreacted absorbent is reacted with residual SOx. The particulate material separated by a dry dust collector 117 is circulated into a conduit 124 and a part of the particulate material separated by a dry dust collector 125 is recirculated to the slurrying process 101.