MANN+HUMMEL To Develop Air Filter Test Rig
Ludwigsburg, Germany - With the new test rig, MANN+HUMMEL now has one of the most modern testing labs for air filter elements in the world. The feature is its new soot particle generator, which can consistently simulate in the laboratory the actual effect of superfine particles on the filtration behavior of filter media. It offers the advantage that air filter elements can be more specifically designed to meet the vehicle manufacturers' requirements.
Up until now, the test dust used by filter manufacturers to record in the lab the filtration efficiency and dust holding capacity of intake air filter prototypes in accordance with ISO 5011 consisted of quartz particles between 0.3 and 300 microns in size. Filter elements are however exposed to increasing quantities of extremely fine particles of less than 1 micron. These are generated from road traffic, industry and houses and consist primarily of soot. Ingress of this fine dust with the intake air into the engine leads to wear and damage to mechanical and electronic components.
Fine dust clogs filter media
In addition, fine dust significantly reduces the life of air filter elements, as superfine particles of soot clog the filter media far quicker than coarse dust. They block the pores in the media, forcing air to flow through an increasingly narrow cross-section and thus increasing the pressure differential of the filter element. Through the resulting increase in fuel consumption and premature clogging of the filter, service life is reduced and costs are increased.
As the results of the lab tests to ISO 5011 could only be applied to road traffic conditions to a certain extent, MANN+HUMMEL has until now supplemented the testing program by carrying out road tests with fleets of vehicles and conducting tests in an external air test rig. These trials accurately recorded the environment, but were held over weeks or months, and under changing traffic and weather conditions.
Results within a day
With the test equipment in the new lab, results are available within a day. MANN+HUMMEL can now also analyze the effect of superfine particles on filtration behavior over and over again under the same conditions. The first air filters tested according to this new standard are already in operation.
The core of the testing unit is a PC-controlled soot generator which burns propane to produce soot particles with an average diameter of 80, 95 or 110 nanometers. The generator is linked to a highly sensitive particle measuring system which continuously monitors the size distribution and concentration of the soot particles.
In addition to the fine dust characteristics, MANN+HUMMEL also tests the filtration efficiency, dust holding capacity, flow resistance, the effect of moisture on the stability of the filter element, and leak-proofness. The company currently produces around 60 million air filter elements a year for passenger cars and commercial vehicles at 11 locations worldwide.
SOURCE: MANN+HUMMEL