PURPOSE: To easily remove NOx by providing an NOx reducing agent supply place in the transition range from a radiation area to a convection area and furnishing a catalyst bed in a specified region.
CONSTITUTION: A vaporized charged martial is passed beside combustion devices 5 and 6 in a cracker tube 4 and heated to the cracking temp. required by a gas by the combustion devices. The cracked gas at a temp. of 800-870°C corresponding to the desired C3H6/C2H4 ratio leaves the radiation area 8 through a conduit 9, a high-pressure vapor is obtained at the same time in a heat exchanger 10, and the cracked gas is indirectly cooled to a temp. of 300-500°C. A convection area 11 is formed at the upper part of the reactor, a heat exchanger 12 is furnished in the convection area, and the preheated naphtha is further heated therein. Consequently, the catalyst volume is reduced, and a pure waste gas is obtainable.
MIHIYAERU HAIZERU
KURAUSU SHIYURIIBENAA
