Liquid filtration media containing melt-blown fibers

Abstract

A filter and filter media configured and arranged for placement in a fuel stream is disclosed. The filter and filter media allow for filtering of liquid fuels, such as diesel fuel. In certain embodiments the filter media includes a media fiber, such as melt blown polyester; and a scaffold fiber, also such as such as melt blown polyester, having a larger diameter than the media fiber. The media and scaffold fibers combine to create a media structure having low solidity and relatively low compressibility, and which contain a pore structure that avoids premature fouling of the filter by fuel degradation products.

Description

[0001]This application is being filed as a PCT International Patent application on Aug. 9, 2012, in the name of Donaldson Company, Inc., a U.S. national corporation, applicant for the designation of all countries except the U.S., and Mike J. Madsen, a U.S. Citizen, and Brian Babcock, a U.S. Citizen, applicants for the designation of the U.S. only, and claims priority to U.S. Provisional Patent Application Ser. No. 61 / 523,068, filed Aug. 12, 2011; the contents of which are herein incorporated by reference.FIELD OF THE INVENTION[0002]The present invention is directed to filtration media, filter elements, and methods of filtering liquid fuels. In particular, the invention is directed to filtration media for the removal of fuel degradation products (FDPs) and other contaminants from liquid fuels.BACKGROUND[0003]Liquid fuels, such as diesel fuel, are used in internal combustion engines of various configurations and sizes. Such fuels must generally be filtered so as to remove particulate ...

AI Technical Summary

Benefits of technology

The present invention describes a filter media that has an upstream layer of melt blown polymeric fibers and a downstream layer of cellulose fibers. The upstream layer removes fuel degradation products to preserve filter life, while the downstream layer removes hard particles. The media has a low compressibility and a high stiffness, which results in a relatively incompressible filter media. The media has a wide pore size distribution to reduce fouling from contaminants. The technical benefits of the filter media include improved filter life, reduced fouling, increased strength, and improved handling.

Problems solved by technology

Such fuels must generally be filtered so as to remove particulate contaminants, which can otherwise create significant problems in engine performance and can result in damage to the engine.

Without such tight pore structures, unacceptable levels of particles can pass through the filter media and detrimentally affect engine performance.

Although melt-blown media can perform adequately in removing particulate contaminants from liquid fuels, the melt-blown media can readily foul from buildup of contaminants other than traditional particulate contaminants.

This premature fouling appears to be particularly pronounced in situations where fuel undergoes repeated heating and cooling cycles, such as in common rail systems used on many diesel engines.

In addition to filter-clogging materials generated as a result of heating and cooling cycles, additional sources of contaminants that can reduce fuel filter performance include ingredients found in various biodiesel mixtures.

Finally, even normal aging of fuel, especially when it occurs at heightened temperatures, can result in production of fuel contaminants that further limit fuel filter life due to fouling and clogging of filter media earlier than would otherwise be expected if only hard particle contaminants were present.

Images