Patent ID: 9255511
Filing Date: 2016-02-09
CPC Classification: B01D,F01N,Y02T

Claim Text:
1. An exhaust purification system with a DPF which collects exhaust particulates in an exhaust gas, a reducing agent injection valve which injects an aqueous urea solution as a reducing agent into the exhaust gas, and an SCR catalyst which purifies a NOx in the exhaust gas by using the aqueous urea solution, the DPF, the reducing agent injection valve and the SCR catalyst being provided in sequence from the exhaust upstream side, the exhaust purification system comprising: an operation state detecting unit configured to detect starting and stopping of an internal combustion engine; a condition establishment determining unit which determines whether there is a possibility of solidification of the aqueous urea solution when the operation state detecting unit detects the stopping of the internal combustion engine; a data storage unit which stores a determination result of the condition establishment determining unit as data; and a blockage-clearing control unit which activates a forced regeneration unit of the DPF for raising a temperature of the reducing agent injection valve based on the determination result from the data storage unit when starting the internal combustion engine so as to raise the temperature of the reducing agent injection valve.