Sintered Metal Filter – Active Regeneration

The SMF AR system is ideally suited toward applications with deviating application profiles and frequently low exhaust gas temperatures. These low temperature applications are more commonly found on construction sites, on mobile machines and static equipment. The SMF AR System (Sintered Metal Filter with Active Regeneration) regenerates autonomously regardless of the exhaust gas temperature.

Actively regenerated particle filter for individual requirements

With this system, the particulate filter can be regenerated at almost every engine operating point regardless of temperature as the required temperature for soot burn off is generated by the SMF® AR system itself. Thanks to its compact design and construction and the modular structure of the system the SMF AR system can be adapted to suit many different applications. The inlet and outlet pipes as well as the mounting brackets can also be tailored to suit a range of machines and vehicles.

Modularity

In order to enable the most economical integration into a range of applications, the SMF AR system is structured in a modular format. The size of the filter, the housing shape and the inlet and outlet cones can be selected based on the requirements of the installation space available.

Technology and functioning method

In the case of the SMF® AR system, exhaust gases are filtered until an optimum quantity of soot has collected on the filter. The system uses a fuel additive which lowers the soot ignition temperature and increases the soot burn off speed. The soot collected can therefore be burned off at an exhaust gas temperature of over 400°C. If the necessary temperature is not reached, as is frequently the case at low load range, the active regeneration support of the system is used in the form of thermo-electric heating elements.

Active regeneration with additive

The system control unit initiates the active regeneration which comprises of heating elements which circle the filter. The collected soot is ignited by the heat energy of the heating elements and the regeneration process ends automatically after the initial ignition of the soot layer. This process is implemented at regular intervals with the aid of a control unit. The control unit also uses sensors to detect the quantity of additive required, the soot load on the filter and also determines the best time to regenerate the filter.

The SMF AR system also self learns the driving cycle to help prevent vehicle ignition switch off which interrupts the regeneration process. As a result of the high soot storage capability of the SMF® AR system, the regeneration is implemented where there is sufficient time rather than at a single time. Any interruption of regeneration by switching off the engine has no negative effect on the function of the system. Another important key aspect of the SMF^® is that its high ash storage capability enables long maintenance and cleaning intervals.

Area of application

The SMF® AR system is predominantly suited for off highway applications, but can also be applied to commercial vehicles and buses. It can also be used in combination with an SCR system for Nitrogen Dioxide reduction. This technology can also be used for static engines and railway or marine engines. HJS-SMF® AR system applications are available for both original equipment and for retrofitting.