A passively regenerated ceramic filter for individual requirements. HJS filter systems are based on filter modules which are manufactured from ceramic materials. They are often used where no large ash quantities occur. These filter systems can generally replace the original acoustic damper in the area of retrofitting and can be adapted individually to the machines and to stationary applications.
These filter systems require no additional regeneration aids, additives or interventions in the engine management. Over the HJS service unit, the respective operating state and cleaning requirement of the filter system can be read off at any time.
In order to enable integration into the most varied applications with low expenditure, the system is structured in modular format. According to installed situation and range of performance, the customer can select between different system sizes and housing shapes, within the framework of the extensive HJS delivery program.
Technology and functioning
The structure of a ceramic particle filter resembles that of a catalyzer. The ceramic filter consists of a great number of parallel, rectangular conduits. So that a filtration of the soot particles from the exhaust gas is possible, these conduits are closed at alternate ends and the ceramic material adjusted so that a matching porosity adjusts.
HJS uses the material cordierite for its filter systems and, for special applications, also the high-temperature-resistant silicon carbide (SiC). Above an exhaust gas temperature of 200°C, the regeneration (cleaning) of the filter starts. The nitrogen dioxide formed with the aid of an oxidation catalyst (NO2) impacts the soot deposited in the conduits. The soot particles are oxidised and reduced in this case. The previously formed NO2 is again reduced to nitric oxide (NO). As a result of this chemical process being repeated continuously, the particle filter cleans itself continuously and usually does not require any additional regeneration aids, such as for example a support of the engine management. The ceramic filter can be supplied with a catalytic coating for the support of the regeneration.
Area of application
The HJS ceramic filter system is also mainly suited for commercial vehicles and buses, however, for off-highway applications, as well as in combination with an SCR. This technology is also used in stationary engines, railways or shipping. HJS ceramic filter systems are available for application both in the original equipment and in retrofit.