The urea dosing module in the automobile exhaust emission system is an important component of the urea exhaust treatment system (SCR system). Its main function is to inject urea solution quantitatively and evenly into the exhaust pipe to reduce nitrogen oxides emissions in the exhaust gas .
The urea dosing module, also known as the metering module or injection device, is a stainless steel injection device specially installed on the exhaust pipe of diesel vehicles. It is responsible for spraying urea aqueous solution (AdBlue or DEF, diesel exhaust treatment fluid) in the form of mist, and chemically reacting with nitrogen oxides in the exhaust under the action of a catalyst to generate harmless nitrogen and water steam. This process helps to significantly reduce the NOx content in the exhaust gas and meet environmental emission requirements.