Search Results

Selective catalytic reduction (SCR) systems have become the preferred technology to deal with NOx emissions in Diesel engines. Their efficiency is highly reliant, among other factors, on the uniformity of distribution - known as Uniformity Index (UI) - of NH3 which is injected into the system through a urea-water solution (UWS). SCR system make use of a mixer component designed to achieve the desired UI levels. However, the great variety of exhaust systems, makes it impossible to employ a universal solution. Therefore, each SCR system requires of a tailor made mixer, capable of achieving the required UI, while preventing urea crystallisation and minimising pressure drops. Computer fluid dynamics (CFD) tools together with optimisation techniques based on the design of experiments (DoE) can be used to obtain the appropriate mixer design.