Patent ID: 8893477
Filing Date: 2014-11-25
Classification: B01D,F01N,G01F,Y02T

Abstract:
1. An exhaust emission purifying apparatus comprising: a reducing agent tank which stores therein a liquid reducing agent or its precursor; a reduction catalytic converter configured to reduce and purify nitrogen oxide in exhaust gas using the liquid reducing agent or its precursor; a reducing agent dosing device comprising an injection nozzle, a pump module, and a dosing module, the reducing agent dosing device configured to injection-supply the liquid reducing agent or its precursor, stored in the reducing agent tank, to the exhaust upstream side of the reduction catalytic converter at a dosing flow rate corresponding to an engine operation state; a sensor which is attached to the reducing agent tank so as to hang from a top wall of the reducing agent tank and has a liquid level indicator measuring a liquid level of the liquid reducing agent or its precursor based on a capacitance change and a concentration meter measuring a concentration of the liquid reducing agent or its precursor based on heat discharge characteristics, the liquid level indicator and the concentration meter being unified; and a control unit with a built-in computer, wherein