Efficient exhaust gas aftertreatment

Liebherr meets the increasingly stricter emissions standards with systems expertise. We developed our own exhaust gas aftertreatment systems, which are optimally combined with our diesel engines. These systems reliably reduce exhaust gas emissions and harmful particles.

D9508 A7 diesel engine: Nitrogen oxide and particle emissions are measured at the test bench.

D9508 A7 diesel engine: Nitrogen oxide and particle emissions are measured at the test bench.

Vertical integration has a long tradition at Liebherr. We manufacture key components and systems ourselves. In view of the stricter emissions standards, we decided on our own injection system including engine control. Liebherr offers a standard basic engine. This engine can be flexibly adapted in accordance with the modular principle with small modifications or by exhaust gas aftertreatment systems. In this way we are able to meet the different emission regulations of different countries and regions with one engine architecture.

SCRonly technology for stage IV/tier 4 final

D946 A7 diesel engine from Liebherr for emissions stage IV

D946 A7 diesel engine from Liebherr for emissions stage IV

For exhaust gas aftertreatment, Liebherr uses SCRonly technology for both stage IV and tier 4 final. The optimised system allows us to observe limit values without the need for a diesel oxidation catalyst (DOC), particulate filter (DPF) and exhaust gas recycling (EGR). The continuous and precise control of emissions by means of on-board diagnostics contributes to the high level of efficiency. At the same time, the efficiency of the SCR catalytic converter was improved. For improved and more accurate metering, Liebherr now injects the AdBlue urea solution with injectors, which permit better atomisation and thus an even more efficient reduction of the nitrogen oxide.

Overview of advantages

The SCRonly-technology from Liebherr without an oxidation catalyst and particulate filter stands out in the industry. The innovative system offers numerous advantages:

  • Saves space during installation
  • Less weight
  • No need to regularly clean a particulate filter
  • Longer oil change intervals
  • Lower procurement and maintenance costs
  • Lower cooling requirement thanks to omission of exhaust gas recycling

Strategy for emissions stage V

Flow analysis of SCR system

Flow analysis of SCR system

The diagram shows the flow pattern and temperature of the exhaust gases. Based on this data, the AdBlue urea solution is sprayed so that it is able to absorb as much of the harmful substances as possible. At the same time, the metal of the housing should suffer as little damage as possible.

Liebherr is already preparing for stage V of the European emissions limit values from 2019 and has developed the innovative SCRFilter system. This system is already used in machines for tunnelling and is certified for stage IV, as well as the Swiss market. The Liebherr solution comprises a DOC catalytic converter, a SCR catalytic converter and a SCR-coated particulate filter. The maintenance-friendly technology permits easy access to the new SCRFilter. The filter needs to be cleaned after 4,500 working hours at the earliest and this can be done in Liebherr's own Reman centres.

Video

The video conveys impressions of the engine production at Liebherr and highlights the advantages of the in-house developed SCR technology.

The video conveys impressions of the engine production at Liebherr and highlights the advantages of the in-house developed SCRonly technology. View video

The video conveys impressions of the engine production at Liebherr and highlights the advantages of the in-house developed SCR technology.

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