Energy reducing system of nox reducing apparatus using waste-heat and steam type gas heater

PURPOSE: The energy saving system of a nitrogen oxide reducing apparatus using waste heat and a vapor type gas heater is provided to increase the using efficiency of energy by preventing the re-exchange of heat between high temperature flue gas and saturated liquid. CONSTITUTION: The energy saving system of a nitrogen oxide reducing apparatus includes a bag filter(105), a steam header(140), a vapor type gas heater(110), a duct burner(115), a selective catalytic reaction column(120), and an induced blower(125)/chimney(130). The bag filter eliminates dust from flue gas generated from the incineration of waste and discharges cooled flue gas without the dust. The steam header collects waste heat form the incineration of the waste and stores the waste heat as steam of 190 degrees Celsius or more. The vapor type heater heat-exchanges the flue gas form the bag filter based on the steam. The duct burner heats the flue gas using auxiliary fuel according to the temperature of the flue gas. The selective catalytic reaction column eliminates nitrogen oxide from the flue gas discharged from the duct burner. The induced blower/chimney discharges the flue gas form the selective catalytic reaction column to atmosphere.