 |
| Fuel filter modul |
 |
MAHLE fuel filter modules optimally condition gasoline and diesel fuels for the combustion process - through the use of high-separation filter media as well as an extended function range. In fuel filters, for example, the optimum fuel pressure can therefore be ensured by a pressure regulator integrated in the fuel filter. The reduced number of interfaces has a positive effect on the emissions of the entire vehicle.
With diesel engines, the range of functions of the MAHLE fuel filter modules can be considerably more complex.
The following functions can be integrated: fuel preheating for avoiding paraffin precipitation, fuel cooling for component protection, as well as diverse sensors and switches. Service signal transmitters are also frequently used owing to the varied fuel qualities in the world market. These functions, combined with individual MAHLE solutions, such as the highly efficient dual-layer water separation system and a patented automatic water disposal system, are unique features of the MAHLE filter modules for passenger cars and commercial vehicles.
Advantages of fuel filter modules
- Multi-layer melt-blown filter media for minute particle separation
- Highly efficient dual-layer water separation in compact design
- New innovative automatic water disposal system
- Modular system structure
- Customer-specific solutions
- Environmentally friendly, completely incinerable filter inserts
- Service-friendly maintenance
New diesel filter media
Steadily increasing demands placed on diesel filter media necessitate the development of new media for greater particle separation, dirt absorption capacity, and therefore extended replacement intervals. Since the available installation space is one of the major limiting factors in the automotive industry, ever-new filter media with improved properties are required. Consequently, in the future multi-layer filter media and systems with gradient structures will be in increasing demand. The use of these new media types enables significantly higher filtration efficiency and higher dust holding capacity while maintaining or even lowering pressure loss. The fiber cross-sections of the filter media are also of great importance for the entire filtration performance. As a result of smaller fiber cross-sections, the number of fibers per volume can be increased, thus improving the dirt absorption capacity for the same installation space.
The extensive selection of MAHLE series production solutions as well as the new enhanced filter media allow an optimal design of the filter inserts as a function of the different local requirements encountered on the various markets. MAHLE has the right filter media, both for passenger car and for commercial vehicle applications. These filters ensure nearly complete separation of particles up to 4 µm and consequently meet even the most stringent commercial vehicle requirements.
Highly efficient water separation
Nearly all commercial vehicles and an increasing number of passenger cars use economical diesel engines with injection systems, which are sensitive to water in the diesel fuel. To protect the injection system from water-related damage, such as corrosion, cavitation, and other negative effects, highly efficient water separation is required. This applies above all to countries with high water contents in the diesel fuel, for example, Brazil, the USA, China, and India.
In addition, more and more vehicle manufacturers rely on pressure systems, which pump the fuel under pressure (e.g. 5 bar) from the tank through the fuel filter to the injection system by means of an electric fuel pump. Since the pump produces a fine diesel-water emulsion, water separation in the fuel filter is more difficult than in an intake-side system, which uses a pump on the engine to take in fuel from the tank. Water present in the tank is not emulsified and can be easily separated on the filter medium in the form of larger drops.
For applications on the pressure side, MAHLE has developed a highly efficient dual-layer water separation system for passenger cars and light commercial vehicles. This dual-layer water separation system is also excellently suited for use in MAHLE fuel filter modules for medium-weight and heavy commercial vehicles. The two-layer design ensures the highly efficient separation of the emulsified water, even for fine diesel-water emulsions. Filter media that unite particle separation and water separation enable the integration of the water separation process in the fuel filter module under extremely compact installation conditions. In addition to dual-layer water separation, MAHLE offers powerful solutions for intake-side applications.
MAHLE fuel filter modules guarantee reliable particle filtration and water separation during the entire service life of the filters, even when using bio-diesel or FAME.
Automatic water disposal system
In regions with high water content in the diesel fuel, the separated water must often be disposed manually. For passenger car applications, this generally requires a trip to a specialty repair shop. For commercial vehicle applications with water separation on the engine-side fuel filter module, manual water disposal is even more complicated. The fuel filter module is frequently difficult to access due to its installation position, and, in addition, drivers of commercial vehicles must drain the separated water nearly every day. This solution is neither service-friendly nor environmentally sound because the daily manual water disposal also increases the likelihood that the environment is polluted by the water that is disposed.
For service and environmental reasons, MAHLE has developed an innovative new product with its automatic water disposal system. This patented solution is regulated by a water level sensor. As soon as a specific water level is reached, a solenoid valve is opened when using the system on the pressure side, or a water separation pump is activated when using the system on the intake side. To ensure reliability, an additional solenoid valve is required for the pressure-side solution. The automatic water disposal is time controlled or is stopped when the lower level of the dual-stage water level sensor is reached. Depending on the application, the water passes the solenoid valve or the water discharge pump and is cleaned by an HC adsorber. Studies show that the water purified by the HC adsorber reaches drinking water quality. An OBD (On-Board Diagnosis) function can be implemented by counting the number of activations of the automatic water disposal system in the electronic controller.