Patent ID: 8800271

Claim:
An SCR system of a vessel for discharging exhaust gas from an exhaust gas source in the vessel to an outside after performing purification of the exhaust gas, the SCR system comprising: an SCR reactor connected at a leading end thereof to the exhaust gas source and comprising a catalyst capable of activation by the introduction of exhaust gas into the SCR reactor; a reducing agent supply line configured to supply NH 3 or urea into the SCR reactor; a two-way air line having a first branch operably connected to the reducing agent supply line and a second branch operably connected to the SCR reactor at a middle portion thereof to supply air to an air soot blower disposed inside of the SCR reactor, the air soot blower configured to blow air supplied from the second branch of the two-way air line toward the catalyst to remove foreign matter from the catalyst; a mixer positioned at the leading end of the SCR reactor to mix the exhaust gas with the NH 3 or urea; and a bypass system for forcing the exhaust gas discharged from the exhaust gas source to bypass the SCR reactor, the bypass system comprising a bypass line connected at both ends thereof to the leading and rear ends of the SCR reactor; and a pair of bypass dampers respectively provided to both ends of the bypass line, the pair of bypass dampers configured to close the opposite ends of the bypass line while opening a path in the SCR reactor in a normal state, but open the opposite ends of the bypass line while closing the path of the SCR reactor in an abnormal or emergency state, the path located in the SCR reactor and between the opposite ends of the bypass line.