Exhaust gas purification system for use in internal combustion engine, has control device providing recycling operation for urea solution such that steam in tank is transferred to discharging pipe via transfer pipe by suction force of pump

摘要

The system has a pump (13a), which pumps stored urea solution in a tank (12). A discharging pipe (P2) is attached to a discharging side of the pump. An admixture valve (20) adds the urea solution into an exhaust gas pipe (10) of an internal combustion engine. A control device (15) implements a recycling operation for recycling the urea solution in the discharging pipe to the tank such that steam in the tank is transferred to the discharging pipe through a transfer pipe by suction force of the pump, which implements back rotation movement during the recycling operation.