Zetor FORTERRA HSX Series, Operator'S Manual, Page: 76 / 222

The tractor is equipped with the engine fulfilling emission limits STAGE IV and TIER 4f. The compliance with
the emission limit is achieved, among others, by the combination of two systems of treatment of exhaust
gases:
a - Diesel Particulate Filter (DPF) designed for purification of exhaust gases. In the diesel particulate filter,
solid particles (carbon black) formed during incomplete combustion of diesel fuel are gathered and then
burnt. The oxidation catalyst (DOC) is a part of the DPF unit as well.
b - SCR - the SCR abbreviation stands for system for cleaning of exhaust gases of diesel engines using the
selective catalytic reduction decreasing the amount of NOx in the exhaust gases. At the same time, the
reduction agent injected into the exhaust system reacts in SCR catalyst with NOx emissions contained in
exhaust gases which are reduced to nitrogen (N2) and water (H2O). The control of the injected amount of
urea is performed using the control unit itself in connection with the control unit of the engine.
To ensure proper functioning of the system, several its parts are monitored so to meet the
required emission limits:
- The level and quality of urea injected in the catalyst SCR.
- The amount of NOx in exhaust gases and temperature in the system.
- Detection of an illegal intervention and any handling to put the system out of order.
1. Filter of solid particles (DPF; diesel particulate filter)
2. Oxidation catalyst (SCR)
3. Urea tank (AUS 32, DEF)
S15N026
SYSTEM OF ADDITIONAL TREATMENT OF EXHAUST GASES
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