DE102008023976A1 - Filter element for use as compact air filter in internal combustion engines, has layer of filter medium, which is arranged on carrier in flow direction - Google Patents

Abstract

A filter element has a layer of filter medium, which is arranged on a carrier in a flow direction. An inflow side filter layer has a filter layer, which is made of fine fibers. The fine fibers are arranged in interior of the filter medium, where the fine fibers are micro- or nanofibers having a diameter of 2 mu m. The carrier is a grating made of polyamide 6.6.

Description

Technical area

The The invention relates generally to a filter element. In particular, it concerns the invention a filter element for use in an internal combustion engine.

State of the art

The The invention relates to a filter element, in particular for filtering Material particles from a gas stream, eg. B. a stream of air. Filter, a substrate with a fine fiber layer or a fine fiber fleece from polymer materials are known. Such materials can be used to form fine fibers, such. B. Microfiber and nanofiber materials with improved stability and Strength can be used.

For example, the US 6,673,136 B2 a filter element consisting of a filter media pack having a substrate having a certain filtration performance, said substrate having a plurality of grooves and at least partially coated on its surface with a layer of fine fibers having a diameter of about 0.01 to 0.5 μm it has been proven that at least 30% of the fibers remain unchanged under certain test conditions for filtration purposes.

Such Nanofiber-coated filter elements show very good deposition performance and high dust storage capacities for ultrafine particles. These high dust storage capacities are caused by a large Fiber surface of the Feinstfaserauflage caused. in this connection an improved particle accumulation is created which inhibits blocking the filter is delayed.

The Nanofiber medium, however, this fine fiber layer can only as two-dimensional Create surface and has a thickness of less than 1 micron on. As a result, the separated particles are in the form of a filter cake built up. This filter cake has decreasing particle size increasing flow resistance. This will lock the media.

It There is a need, therefore, to provide filter elements incorporating the avoid the disadvantages of the prior art.

Disclosure of the invention

It is therefore the object of the present invention, a filter element, especially for use in an internal combustion engine, the blocking of the filter medium for the finest particles delayed.

It is another object of the present invention, such To provide filter element, in which the separation efficiency on high level can be maintained.

These and further tasks are performed by the filter elements according to the independent Claims 1, 3 and 6 solved.

advantageous Embodiments of the invention are in the subclaims explained.

Brief description of the drawings

The The invention will be described in more detail below with reference to the drawings explained. Showing:

1 an uncoated PA 6.6 grid with a mesh size of 100 ± 10 μm;

2 the grid off 1 with a coating of nanofibers;

3 the coated grid off 2 in cross-section;

4 an uncoated PA 6.6 grid with a mesh size of 102 ± 6 μm;

5 the grid off 4 with a coating of nanofibers;

6 the coated grid off 5 in cross-section;

7 an uncoated PA 6.6 grid with a mesh size of 150 ± 9 μm;

8th the grid off 7 with a coating of nanofibers; and

9 the coated grid off 8th in cross section.

Embodiment (s) of the invention

A the first solution is not the layer of fine fibers on the surface of the substrate, but inside the To arrange medium. The fibers may be nanofibres, Microfibres, etc. These filter media with integrated fine fibers show very good deposition rates and high dust storage capacities for fine particles. Due to the fine fibers integrated into the medium can reduce or delay the blocking of the medium become.

Another solution is to provide so-called "non-filtering supports" with a nanofiber overlay. In the process, meshes are made of polya mid 6.6 (PA 6.6) with a coating of nanofibres. The mesh size of the grid can vary. 1 shows an uncoated PA 6.6 grid with a mesh size of 100 ± 10 μm, 2 such a grid with a coating of nanofibers. 3 shows the coated grid in cross section. The air permeability of the uncoated lattice is ~ 9,880 l / (m ² s), that of the coated lattice 800-1,500 l / (m ² s). The screen fineness is 69.9 n / cm, the thickness 70 μm and the basis weight 24 g / cm ² . In 4 a PA 6.6 grid is shown which has a mesh size of 102 ± 6 μm. 5 shows the coated grid and 6 a cross-sectional view of the coated grid. The air permeability of the uncoated lattice is ~ 8,600 l / (m ² s), that of the coated lattice ~ 1,500 l / (m ² s). The screen fineness is 65 n / cm, the thickness 80 μm and the basis weight 35 g / cm ² . Another PA 6.6 lattice is in the 7 to 9 shown. Here the mesh size is 150 ± 9 μm. The air permeability of the uncoated lattice is ~ 11,000 l / (m ² s), that of the coated lattice is ~ 650-840 l / (m ² s). The screen fineness is 47 n / cm, the thickness 95 μm and the basis weight 35 g / cm ² . 7 shows the uncoated grid, 8th the coated grid and 9 the coated grid in cross section.

Yet sees another solution according to the invention before, fibers with a mean fiber diameter of ~ 2 microns instead of those with a diameter of 0.01 to 0.5 microns to use. An advantage of this arrangement is the large one Rußkapazität.

Another approach for the realization of the task is to replace the very thin nanofiber layer by a volumetric Feinstfaserlage and thus build a depth filter layer of fine fibers, which stores the deposited particles over the entire thickness of the finest fiber layer of the medium (the ultrafine fiber layer) and thus prevents the construction of a comparatively dense filter cake. For this purpose, a Feinstfaserschicht of meltblown fibers is used. The fibers have a mean fiber diameter of -2 pm, with the lower fiber diameter d _{50-2σ being} around 700 nm.

The meltblown layer is characterized as follows: Average fiber diameter: d ₅₀ = 2.0 μm; Weight: 5-20 g / m ² , preferably 10 g / m ² ; Thickness: 0.01-0.3 mm, preferably 0.08-0.13 mm; Air permeability: 500 l / m ² s-5,000 l / m ² s, preferably 1,000-1,500 l / m ² s), material: polycarbonate, polypropylene, polyamide, PET, preferably PBT, inter alia

The carrier consists of a cellulose-based filter medium with a basis weight between 50 and 200 g / m ² and air permeabilities between 50 and 1000 l / m ² s. The thickness of the carrier material is 0.2-0.5 mm. The carrier is impregnated flame retardant. The impregnation is carried out as NC impregnation when used as a compact air filter to be cured phenol resin impregnation in star-folded elements.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - US 6673136 B2 [0003]

Claims (19)

Filter element, in which at least one layer of a filter medium is arranged on a carrier in the flow direction, characterized in that the upstream filter layer has a filter layer of fine fibers, wherein the fine fibers are arranged in the interior of the filter medium. Filter element according to claim 1, characterized in that that the fine fibers are micro or nanofibers. Filter element, in which at least in the flow direction a layer of a filter medium disposed on a support and the upstream filter layer is a filter layer made of fine fibers, characterized in that the carrier a grid of polymide 6.6 is. Filter element according to claim 3, characterized in that that the mesh size of the grid between 100 and 150 microns is. Filter element according to one of claims 3 or 4, characterized in that the filter layer fibers with a has mean fiber diameter of ~ 2 microns. Filter element in which at least one layer of a filter medium is arranged on a carrier in the flow direction and the upstream filter layer has a filter layer of fine fibers, characterized in that the upstream filter layer is a voluminous Feinstfilterschicht of meltblown fibers having a thickness in the range of 0.01-0, 3 mm, the average fiber diameter of the meltblown fibers is about 2 μm, the _lower fiber diameter d _{50-2σ is} about 700 nm, and the weight of the _superfine fiber _layer is in the range of 5-20 g / cm ² . Filter element according to claim 6, characterized the thickness of the microfiber layer is 0.08-0.13 mm. Filter element according to claim 6, characterized in that the weight of the Feinstfaserschicht 10 g / cm ² . Filter element according to one of claims 6 to 8, characterized in that the air permeability of the Feinstfaserschicht is in the range of 500-5000 l / m ² s. Filter element according to claim 9, characterized in that the air permeability of the Feinstfaserschicht in the range of 1,000-1,500 l / m ² s. Filter element according to one of claims 6 to 10, characterized in that the material of the Feinstfaserschicht is selected from the group consisting of PBT, polycarbonate, Polypropylene, polyamide and PET. Filter element according to one of claims 6 to 11, characterized in that the carrier is made of a cellulose-based Filter medium exists. Filter element according to claim 12, characterized in that the basis weight of the carrier is between 50 and 200 g / cm ² . Filter element according to claim 12 or 13, characterized in that the carrier has an air permeability between 50 and 100 l / m ² s. Filter element according to one of the claims 12 to 14, characterized in that the thickness of the carrier material in the range of 0.2-0.5 mm. Filter element according to one of claims 12-15, characterized in that the carrier impregnated flame retardant is. Filter element according to one of the claims 6 to 16, characterized in that the connection between the carrier and Feinstfaserschicht done by calender. Filter element according to one of claims 6-17, characterized in that the Feinstfaserschicht on the carrier is glued on. Use of the filter element according to one of the claims 1-18 as a compact air filter in internal combustion engines.