Nowadays, heavy diesel trucks come with the most current EPA compliant equipment. This equipment comes in the form of two different methods used in the after treatment of the exhaust emissions. These methods are Selective Catalytic Reduction (SCR) and Exhaust Gas Recirculation (EGR). Either are used to reduce NOx. In the early days, most trucks had only an EGR system with a diesel particulate filt...
At present, two technical solutions are adopted to solve the problem of diesel exhaust emissions. One is SCR technology , another is EGR+DPF. Principle of EGR (Exhaust Gas Recirculation): The technology introduces engine exhaust gas into the intake pipe to reduces the oxygen concentration entering the cylinder and controls the combustion speed as well as lowers the combustion t...
There have been two approaches to regulatory compliance: EGR and SCR. EGR was implemented January 1, 2007 and SCR was implemented January 1, 2010. EGR was able to meet the Federal Standards for 2007, but not able to meet the new standards for 2010. In 2007 the Emissions Standard was 1.2 NOx (g/hp.pr) and it could be reached using EGR technology, but January 1, 2010 this standard dropped to .02g/HP...