ENERGREEN RoboMAX, Use And Maintenance Instruction Manual, Page: 59 / 105

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© 2017 Energreen Srl
Professional machinery
6.8 - EXHAUST GAS POST-TREATMENT SYSTEM
Exhaust gas
inlet
7
6
5
4
1
2
3
Exhaust gas
outlet
6.8.1 - OVERVIEW OF THE DPF SYSTEM (PARTICULATE FILTER)
The DPF consists of a Diesel Oxidation Catalyst (DOC) and a soot Filter (SF). The purpose of the
DPF is to prevent particulates, which are harmful to both man and the environment, from being
released into the air. This is achieved by the DOC that breaks down the dangerous molecules
and the SF that collects the particulates. If the level of particulates that have accumulated in the
SF is high, it will clog and reduce the performance of the engine. A means to regenerate the SF is
therefore required. The engines used by ENERGREEN use a continuous regeneration method i.e.
they regenerate the filter at the same time as they collect the particulates. In order to increase the
regeneration performance, the particulates collected in the SF are burnt with the NO
2
generated
in the DOC and with the O
2
in the exhaust gases. At the same time, the DOC purifies the exhaust
gases by converting, for example, acetylene (HC) and carbon monoxide (CO) into water (H
2
O) and
carbon dioxide (CO
2
) respectively.
6.8.2 - PARTICULATE FILTER MAINTENANCE AND ASSISTANCE
In addition to particulates, ash also accumulates in the SF. This is mainly due to metal additives
contained in lubricating oil. A small quantity of lubricating oil is burned in the combustion chamber,
which is then collected in the SF together with the combustion gases. This small amount of
metallic ash cannot be burned in the DPF. It therefore builds up over time and causes the engine
to lose pressure, as well as having other negative effects on it. In this case, the DPF has to be
cleaned. ENERGREEN recommends doing this every 6000 hours of operation.
Make sure that you use specific fuel and lubricating oil so that the DPF can function correctly. Use
a type of diesel that has a very low sulphur content ≤ 15 ppm. If you use a fuel other than the one
specified, it might prevent the DPF from being regenerated properly by generating an excessive
quantity of particulates. This results in an excessive fuel consumption and the deterioration of the
engine (reduced performance) due to the continuous activation of the regeneration process.
1 Filter element
2 Differential pressure sensor
3 Silencer
4 Soot filter casing
5 Soot filter (SF)
6 DOC casing
7 Diesel oxidation catalyst (DOC)