DE1922976A1 - Filter insert for liquids, especially for the lubricating oil of Bronnkraftmaschinen - Google Patents

Description

May 5th 1969

Applicant: Filterwerk Mann ft Hummel GmbH, Ludwigsburg, Hindenburgstr. 37-45

VSS 570

Filter insert for liquids, in particular for the lubricating oil of internal combustion engines

The invention relates to a filter insert for liquids, especially for the lubricating oil of internal combustion engines, with a zigzag folded one on the downstream side Filter material comprising pleat spacers made of a fine-pored filter paper and one of these at least in the area coarse-pored filter paper held at a distance from the surfaces by projections.

Filter inserts with zigzag folded filter paper as Filter material have become established for many applications, because they have a good degree of separation with a relatively large surface have and are inexpensive to manufacture, so that a dirty insert is thrown away and replaced with a new one can be replaced. If very fine-pored filter paper is used, this also results in a particularly high level of contamination Small grain size means a good degree of separation, however, a correspondingly large filter surface and thus a large structural volume must be used be used, because otherwise the flow resistance becomes unacceptably high, all other things being equal With coarse-pored filter paper, the flow resistance is correspondingly lower »and» is too proportionately

009847 / $ 144

small sizes. But the degree of separation decreases because with increasing pore size, more small and larger particles can pass through.

It is known that the different properties of fine-pored and coarse-pored filter papers are due to their special arrangement in the flow path to combine the liquid. For example, coarse-pored ones are used for filtering the lubricating oil of internal combustion engines Main flow and fine-pored bypass flow filters, whose filtei * inserts can be housed in a filter housing. For this, however, the effort is usually considerable, especially since for the Bypass flow filter requires a special line that leads directly back to the lubricating oil reservoir. Such a Only use the arrangement if the liquid to be filtered is circulated.

In other previously known constructions, a coarse filter and a fine filter are arranged in parallel in the main flow in a housing. The assumption here is that the coarse filtering carried out in any case holds back dangerously large particles while the fine filter also separates smaller particles from the partial flow of the liquid that passes through it. By appropriately dimensioning the insert parts or by switching on flow restrictors, the proportions of the limits the liquid flowing through the different filter materials. Such an arrangement can also be used where the liquid is not circulated, but only relatively small filter areas result for tolerable sizes. In addition, when the filter materials are arranged concentrically, the supply and discharge of the liquid cause difficulties.

Another possibility for combining coarse-pored and fine-pored filter papers is to arrange the filter materials one behind the other in the main flow. The flow is first through the coarse-pored filter paper in order to separate out the coarser impurities, and only then through the fine-pored filter paper in order to also trap smaller particles. Such a stage filter insert is known from the German utility model 1 719 795 . Spatially bind these step fiites

VSS 570.>

to accommodate well. But they have the disadvantage that their Tool life, d. H. their service life up to the renewal necessary due to clogging, practically exclusively from the fine-pored paper is determined. Because the upstream coarse-pored paper lets through precisely those impurities with the smaller particles that clog the finer pores of the downstream paper.

You object of the invention is to use simple means to improve the service life of the filter insert of the type shown at the beginning without requiring more space.

According to the invention, the object is achieved in that the fine-pored paper in a known catfish with a uniform is provided over the surface distributed holes and that the diameter of the holes is 0.5 to 2 mm and the entire Hole area 0.05 to 0.5 per thousand of the total surface of a Paper layer.

In the context of the invention, “coarse-pored” should be understood to mean a filter paper which has an average filter fineness of approximately 12 to 18 microns. These values that for fine-pored filter paper are approx. 1 to 8 microns, apply to the most outrageous filter papers with a single pass.

The filter element of the invention has practically the when new equally good degree of separation, as it has an insert with unperforated fine-pored paper. If the degree of separation remains good, the service life is several times longer than that of a step filter insert with unperforated fine-pored paper. Without additional material expenditure and without taking up a larger building volume, the dtr is therefore useful the filter insert has increased significantly.

The fine-pored paper can be the coarse-pored in the direction of flow be upstream. The fine-pored paper is arranged on the downstream side like a gate, but with another one, however no more significant improvement in service life is achieved.

009847 / $ 144. _4th

YSS 570.

Regarding the state of the art, it should also be mentioned that from German Auslegeschrift 1 029 345 an annular filter insert with several zigzag-shaped folded paper layers emerges as known, which have a porosity that becomes finer in the direction of throughput and rests on a perforated support layer made of relatively stronger paper . Although this support layer can also consist of filter paper, it has the task of mechanical support and, given the large number of relatively large holes provided, is not suitable for exerting an influence on the degree of separation and the service life of the filter insert.

The invention is explained below with reference to in the drawings The illustrated examples are explained in more detail. Show it:

Figure 1 is a schematic representation of a filter plate with zigzag folded filter material,

FIG. 2 shows an annular filter insert with a zigzag-shaped folded filter material in an axial view and partly in section,

FIG. 3 shows a section through the filter material used in the filter insert of FIG. 1 along the line III - III of Figure 4 in an enlarged view,

FIG. 4 shows a section along line IY-IY in FIG. 3,

FIG. 5 shows the increase in flow resistance of the filter material of the invention as a function of the service life compared to known filter materials and

FIG. 6 shows the degree of separation of the filter material of the invention as a function of the service life in comparison with known filter materials.

In the filter plate of Figure 1, a zigzag folded filter material 1 is sealed on its periphery in one Frame 2 attached. The filter element of Figure 2 consists of

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a ziek-zag-shaped folded filter material 3 _f which is glued together to form a ring and sealed at its front ends by annular end disks 4.

The filter material consists of a fine-pored filter paper 5 with an average filter fineness of approx. 5 microns and a coarse-pored filter paper 6 with an average Filter fineness of approx. 15 microns. The coarse-pored filter paper 6 has projections 7 and corrugations 8 directed against one another. The fine-pored filter paper 5 is provided with band holders 9. Projections 7, beads 8 and fold spacers 9 are through Bulges formed on the filter paper. The filter papers rest against one another at the folds 10, 10a and are otherwise held at a distance from one another by the projections 7 in the area of the surfaces. The beads 8 are opposite Areas of the coarse-pored paper 6 on the upstream side through which Fold spacer 9, the opposing surfaces of the fine-pored filter paper 5 on the downstream side are kept at a distance from one another.

In the exemplary embodiment, the fine-pored paper has a total surface area of 7000 cm2 with 100 fold areas of 70 cm ^ each. In Two holes 11 with a diameter of 1 mm are arranged on each fold surface. The total hole area is thus a little more than 0.22 Per thousand of the total surface of the paper layer.

The filter material flows through in the direction of arrow A, so that the fine-pored paper 5 is arranged on the downstream side.

The beneficial effect of the filter element of the invention goes from Figures 5 and 6 of the drawing. In the diagrams, the behavior of four different filter materials is compared. It means:

dotted lines 12 and 22:

Filter material made from a layer of fine-pored filter paper »

0098A7 / U4B

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dash-dotted lines 13 and 23:

Filter material made of a layer of coarse-pored filter paper,

dashed lines 14 and 24:

coarse-pored and downstream fine-pored, unperforated

Filter paper in step switching and

uninterrupted lines 15 and 25:

the filter material used in the execution example.

The diagrams show that the flow resistance of the Filter material made of fine-pored filter paper according to line 12 increases rapidly with increasing pollution. Accordingly, the service life is extremely short. Sin very similar The behavior according to line 14 is shown by the filter material, in which the coarse-pored filter paper is followed by an unperforated, fine-pored filter paper in step switching. That Filter material made of coarse-pored filter paper has a significantly longer service life according to line 13, but has according to the course of the line 23 in FIG. 6, a poor degree of separation »because a relatively large amount of dirt passes through the rough forums will be let through.

Sin far more favorable behavior according to lines 15 and 25, on the other hand, shows the filter material of the invention. This filter material has a relatively long service life good degree of separation. The flow resistance only reaches impermissibly high values after a long period of time. The explanation for this behavior is probably due to the fact that in the case of clean paper initially only a small amount of liquid flows through the holes in the fine-pored Paper 5 flows so that the increase in the degree of separation initially takes a similar course as that of the unperforated fine-pored paper With increasing contamination of the perforated fine-pored paper, more liquid flows through the holes, However, the portion of liquid that traverses the filter paper itself when the flow resistance increases is filtered more finely. At the same time, it has the filtering effect of the coarse-pored Papers improved somewhat by building up "a filter cake" ·

All in all, there is still a tolerable flow resistance over a number of times more than known stakes for a longer period of time during which the deposition degree is still increasing. Only when the coarse-pored paper clogs does the flow resistance reach impermissibly high values. she Holes in the fine-pored paper are still open.

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Claims (2)

Expectations Filter insert for liquids, in particular for the lubricating oil of internal combustion engines, with a zigzag-shaped pleated filter material made of a fine-pored filter material, which has creases on the outflow side and has pleated spacers Filter paper and a τοη this at least in the area of the surfaces, coarse-pored filter paper held at a distance by projections, characterized in that the fine-pored paper (5) in a manner known per se with a perforation evenly distributed over the surface * can be seen and that the diameter of the holes (11) is 0.5 to 2 mm and the entire hole area makes up 0.05 to 0.5 per thousand of the total surface of a paper layer. 2. Filter insert according to claim 1, characterized in that the fine-pored paper (5) is arranged on the downstream side. 0098A7 / UA8 Blank page