Bigpuddie
Gold Member
- Joined
- Aug 16, 2018
- Messages
- 457
- Tractor
- Massey Ferguson 4707
That's not entirely accurate. They don't have a regen which forces the tractor to burn hot for a period of time to burn the soot off of the collector but MF (and Mahindra) has a mCRD (DOC system) system which runs hotter all the time to burn off the soot. This is not new technology and is really is dishonest for a tractor mfg to tout this as a benefit over DPF.
DOC is a catalytic converter. The exhaust gas passes through a material which oxidizes/breaks down the environmentally "harmful" stuff. "The diesel oxidation catalyst is designed to oxidize carbon monoxide, gas phase hydrocarbons, and the SOF fraction of diesel particulate matter to CO2 and H2O"
A DPF is a more extensive breakdown system. It usually has a DOC, then a DPF. Some systems also use Diesel Exhaust Fluid (DEF), in addition, which is yet another addition, spraying that fluid the exhaust to further break down the "harmful" particles.
" Exhaust gas passes through the DOC and then into the DPF where Pariculate Matter is collected on the walls of the DPF. The PM collected is then oxidized to remove it from the DPF. This is known as regeneration. When operating conditions maintain sufficient exhaust temperatures, the DPF is continually self-regenerating. This is known as passive regeneration and results in clean exhaust out of the tailpipe. On very infrequent occasions, an active self-regeneration is required to remove a build-up of PM in the DPF, due to insufficient exhaust temperatures. Exhaust temperatures are raised by injecting a small amount of fuel upstream; The resulting chemical reaction over the DOC raises exhaust gas temperatures high enough to oxidize the PM from the filter."
What I said was entirely true. I said " It has no DPF or regen". "It is an excellent tractor". What I said was true. I know a thing or 2 about them. They have a very simple system which requires no maintenance. No DPF, No DEF, and no regeneration.