3.4.1. SCR system overview Tier 4fΒΆ
Description
The DNOX2.2 is a urea dosing system developed for medium and heavy duty SCR applications. The main operation principle is simple: the DNOX2.2 system injects aqueous urea-water solution into the exhaust line upstream to the SCR catalyst. The chemical reactions inside the catalyst convert the NOx and the urea to harmless nitrogen and water. The urea-water solution, most commonly known as Diesel Exhaust Fluid (DEF) or AdBlue, is defined in the standard ISO 22241.
SCR process
The SCR system overview is shown in figure SCR system overview.
SCR system overview