Wärtsilä NOx Reducer (NOR)
The Wärtsilä NOx Reducer (NOR) is optimized and validated for Wärtsilä medium-speed engines in terms of reliability, easy installation and meeting compliancy over whole lifecycle. It is available for both newbuild and retrofits and is compatible for operation on current and future marine fuels. Furthermore, with the Wärtsilä NOx Reducer, the overall performance of the engine and exhaust aftertreatment is optimized in terms of emissions reduction, noise abatement, and engine efficiency. Future engine modifications are easier with OEM SCR system. Wärtsilä provides IMO and EPA Tier III EIAPP certificates for a complete package of an engine and a SCR unit. Beyond IMO Tier III, other ultra-low NOx emission levels are also available. The SCR system can also be integrated with different silencers.
Components & Design
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Technical Data
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Common failures & inspection points
Six-monthly visual inspection of absorber for signs of erosion and corrosion; pressure test of spray headers (low pressure = erosion); inspection for wear on venturi walls and deflector plates
Weekly inspection of spray headers and header on plugging or erosion; inspection of liquid pressure gauges to detect abnormally low pressures (indicator of erosion); six-monthly internal inspections for plugged or eroded nozzles
Annual full service and calibration of all sensors by certified technicians; regular inspection for probe fouling and sensor sensitivity; calibrate CEMS and water monitoring systems per manufacturer specifications
Continuous monitoring of inlet and outlet water quality; documentation of pH (min. 6.5), PAH, turbidity, temperature (max. 60°C); annual sampling to be performed no later than after first year of operation; 3-year retention of all test results
Wall thickness measurements of all effluent pipes and overboard lines at every annual class survey (DNV requirement); visual inspections for signs of corrosion and erosion; inspection of integrity of pipe supports and welds; particular attention to acid corrosion prior to seawater dilution
Six-monthly internal inspections of mist eliminator for fouling, plugging and corrosion; inspection for solids accumulation in eliminator; functional test of eliminator washdown systems; cleaning or replacement when damaged
Type-general inspection and maintenance points for this equipment category — not model-specific.
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