City-Filter® sets the standards
The diesel particulate filters (DPF) keep the air we breathe clean. Very effectively they retain the particles of soot and particulate matter resulting from the combustion of diesel and they burn them. This is ensured by the innovative filter of HJS, for which the company was awarded the German Environment Prize (Deutscher Umweltpreis) in 2003.
The filters we offer are tested by the German Technical Inspection TUV and recommended by the largest automobile association in Germany, the ADAC. All systems have the approvals required by EU regulations and have been developed specifically for retrofits. They require no maintenance and lasts for the lifetime of the vehicle.
Independent tests have shown that the City-Filter® sets the standards in retrofit filtering.
- Health and Environmental Protection - By placing the HJS City-Filter® in your vehicle, you send a powerful message about your environmental awareness because the filter will allow you to reduce the particulate emissions in a diesel car up to 70% and to contribute to the protection of the environment and human health.
- Unlimited access to low emission zones - By placing an HJS City-Filter®, you do not have to worry whether you are able to drive in some city in Greece and Europe due to increased emissions.
- Fiscal / Financial incentives - Many countries in Europe, reward retrofitting vehicles with a cash incentive at tollbooths or taxation.
- Maintaining the value of the vehicle - If a diesel vehicle is not equipped with a filter, the resale value drops significantly.
The technology
With its unique design and materials, the City-Filter® offers great advantages compared with conventional systems. The rugged design, the excellent resistance to high temperatures and the very high retention capacity of smoke provide the perfect base for retrofitting diesel vehicles. The HJS City-Filter® requires no maintenance and will last for the lifetime of the vehicle. Also, it requires no extra sensors or electronic equipment, or additional in the fuel.
The City-Filter® is tested in Germany by TÜV and has the approval required under EU regulations. The filter is available for a wide range of different models of cars and commercial vans, such as Mercedes Benz-Sprinter, Ford Transit, Duacto Fiat, Iveco Daily and many others.
How does the filter work
The hot exhaust gases from the engine - which contain soot particles – are driven into the filter housing and through the sintered metal filter (SMF®) developed by HJS. The gaseous components flow through the microporous filter pockets. The soot particles, including very fine particles are trapped on the surface and deposited in the individual pockets of the filter.
The regeneration of the filter
The regeneration (cleaning) of the filter starts when the exhaust temperature reaches approximately the 200 ° C. Nitrogen dioxide (NO2) is formed with the aid of the catalyst and it is contacted with the soot deposited in the pockets of the filter, causing oxidation and decomposition of the soot particles. The NO2 is then reduced to nitric oxide (NO). This chemical process is repeated continuously, so that the HJS City-Filter® is regenerated continuously without requiring additional aids for the regeneration, such as assistance from the engine management system.
The HJS City-Filter® Combi
The HJS City-Filter® Combi consists of an embedded catalyst or has a very effective catalytic coating, to ensure optimum regeneration when achieve the necessary exhaust gas temperature.
The Combi filter helps vehicle owners to save money when placing a particle filter, especially when the vehicles are not equipped with the necessary catalyst, such as most light trucks. With these systems HJS Combi, a new catalyst or catalytic coating of the filter itself is included in the purchase price.
