mobile machinery (NRMM), engine power ranges and engine emissions levels.
Suitability for a particular application depends on how hard the engine is working during the normal operation of the machine. This affects the exhaust gas temperature, which needs to be above a certain level for at least 50% of the time for these systems to regenerate reliably.
The other factor is the balance of NOx to particulate level in the exhaust gas, which is often determined by the certified emissions level of the engine.
system has the filter coated with catalyst as well as having a Diesel oxidation catalyst (DOC) in front of the filter (as in the CRT®
) and this extends the operating window of the filter system to allow reliable regeneration
with lower exhaust temperatures or lower NOx
to particulate ratio in the exhaust gas.
The oxidation catalyst removes CO and HC and oxidises some of the NO in the exhaust gases to NO2. This NO2 then reacts with the PM trapped in the filter, producing NO and CO2. Some of the NO is then reoxidised to NO2 in the filter, which then reacts with more trapped PM. This enables the system to regenerate in applications with very low exhaust gas temperatures or low NOx:PM ratios in the exhaust gases.
Johnson Matthey CRT® and CCRT® systems have a long track record of reliable, trouble free operation in thousands of retrofits to construction machines and other non-road machinery.
Our specialists can advise which system is most suitable for your specific application.