BlueMAX™ PLUS-Series (SCR+Passive DPF)

BlueMAX™ PLUS-Series - Technology

The main components of the BlueMAX™ PLUS-Series system include the Selective Catalytic Reduction (SCR) catalytic converter, the computerized Urea Dosing System (UDS), the urea tank (see diagram) and the Diesel Particulate Filter (DPF). The urea control strategy relies on Nitrogen Oxides (NOx ) concentration measurements by a sensor positioned upstream of the Selective Catalytic Reduction (SCR) catalyst. Based on the NOx sensor signal in combination with an engine air mass flow sensor and temperature sensors, the computer calculates the amount of urea which needs to be injected for optimum NOx reductions. The NOx sensor-based control strategy makes the system very suitable for both original equipment and retrofit applications. System calibration (i.e. engine mapping) is not required and the system can be installed on a wide range of diesel engines, both mechanically and electronically controlled.

BlueMAX™ PLUS-Series System Schematic Drawing

BlueMAX™ PLUS-Series - Performance

Urea (in the form of a 32.5% water-based solution) is metered by a computer controlled dosing pump into the exhaust pipe upstream of the Selective Catalytic Reduction (SCR) catalyst through an injection nozzle. Compressed air from the air brake line or a standalone air compressor is used to atomize the urea for optimum dispersion, to maximize the Nitrogen Oxides (NOx) reductions and minimize the amount of urea required. The injected urea solution evaporates in the hot exhaust gas and decomposes producing ammonia. Through catalytic reactions with ammonia, NOx emissions are reduced to harmless products including nitrogen and water vapor. The BlueMAX™ PLUS-Series system includes an ammonia slip catalyst (oxidation catalyst) as a standard feature. The ammonia slip catalyst prevents the possibility that unreacted ammonia is released from the vehicle tailpipe. The catalyst consists of a metallic monolith honeycomb substrate coated with platinum group metal catalyst. The honeycomb structure with many small parallel channels presents a high catalytic contact area for the exhaust gases. Due to the presence of an oxidation catalyst reductions in Carbon Monoxide (CO) and Hydrocarbon (HC) emissions are achieved in addition to ammonia slip control.  Typical conversion efficiencies NOx as well as for CO and HC are illustrated in the graphs below. Additionally, the BlueMAX™ PLUS-Series includes a passive Diesel Particulate Filter (DPF) for Diesel Particulate Matter (DPM) control. The soot filtration efficiency of the filter increases with the soot loading in the unit. Even at low soot loads, the filter efficiency exceeds 90% (blue line in Figure below). The visible smoke is completely eliminated by the filter, resulting in a dramatic improvement of smoke opacity readings.

BlueMAX™ PLUS-Series - Designs and Options

BlueMAX™ PLUS 100 - Verification

The BlueMAX™ PLUS 100 Selective Catalytic Reduction (SCR) system represents the industry’s only Nitrogen Oxides (NOx) and Particulate Matter (PM) retrofit emission control device to be commercially available to the non-road market. Nett Technologies’ BlueMAX™ PLUS 100 SCR system has been designed to reduce NOx and PM by a minimum of 85% from medium-and heavy-duty non-road diesel engines ranging between 75 and 560 kW (100-750 hp). In addition to removing NOx and PM, the system also has the added benefit of reducing Carbon Monoxide (CO) emissions by 95% and Hydrocarbons (HC) by 60%. This product is well suited for known PM2.5 and ozone nonattainment areas were controlling both PM and NOx are key factors towards adopting appropriate State Implementation Plans (SIPs) under the Clean Air Act.

The BlueMAX™ PLUS 100 system consists of a passive Diesel Particulate Filter (DPF) followed by a urea SCR system. “The BlueMAX™ PLUS 100 is a great retrofit emission control solution for non-road engines certified to Tier 1, 2 or 3 emission standards. The system is a durable and versatile emission control solution that extends the years of usage of existing construction and non-road equipment. Thanks largely to its direct-fit design, the system not only meets the latest regulations but is highly efficient in its operation.

Criteria to achieve emission reductions

The following criteria must be met in order for appropriately retrofitted engines to achieve the aforementioned emission reductions:

1. Baseline engine must be in a certified configuration and operating on fuel with less than 15 ppm sulfur.
2. Exhaust temperature data logging will be performed before each installation, and exhaust temperatures must be above 325 degrees °C for at least 25% of the normal duty cycle. As there may be significant variations from application to application, Nett Technologies will review actual engine operating conditions and perform temperature data-logging prior to retrofitting an engine with the BlueMAX™ PLUS 100 system to ensure compatibility.
3. Each installation will be equipped with a monitoring system that displays warning lights and error codes visible to the operator, providing urea tank level and diagnostic information.
4. The engine/equipment must not be equipped with a crankcase oil burning system.
5. The engine should be well maintained and not consume lubricating oil at a rate greater than that specified by the engine manufacturer.
6. The engine must not have been originally certified or equipped with a DOC or diesel particulate filter (DPF).
7. The DPF component of the system is recommended for service every 1000 hours of use.

For more information please visit EPA website https://www.epa.gov/verified-diesel-tech/nett-technologies-inc-bluemaxtm-plus-100-selective-catalytic-reduction-scr