Oil mist separator

<td> (12)</td><td></td><td></td>

<td> (21)</td><td>Application number:</td><td>A 773/2013</td>

<td> (22)</td><td>Registration date:</td><td> 08.10.2013</td>

<td> (45)</td><td>Published on:</td><td> 15.03.2015</td>

Patent (51) Int. CI .: F01M 13/04 (2006.01)

<td>(56) Citations:</td><td> (73)</td><td>Patent holder:</td>

<td>CN 201198776 Y</td><td></td><td>GE JENBACHER GMBH &amp; CO OG</td>

<td>JP 2010248934 A JP 2001200713 A</td><td></td><td>6200 JEN BACH (AT)</td>

<td>US 4289583 A</td><td> (72)</td><td>Inventor: Wall Günther 6323 Bad Häring (AT) Laubach Johannes 6116 Weer (AT) Madl Wolfgang 6094 Axams (AT) Trenkwalder Thomas 6067 Absam (AT)</td>

<td></td><td> (74)</td><td>Representative: Torggler Paul Mag. Dr., Hofinger Stephan Dipl.Ing. Dr., Gangl Markus Mag. Dr., Maschler Christoph MMag. Dr. innsbruck</td>

AT 514708 B1 2015-03-15 (54) Filter device (57) Oil mist separator for separating in a carrier gas (2), in particular

Crankcase ventilation gas one

Internal combustion engine (1 5) containing oil with at least one filter device (1) for separating liquid suspended particles from a carrier gas (2), in particular for separating oil from an oil mist, comprising a housing (3) with at least one inlet opening (4) for Introducing the carrier gas (2) and at least one outlet opening (5) for discharging the filtered carrier gas (2), at least one filter insert (6) being arranged in the housing (3), which can be flown through by the carrier gas (2) along a flow direction (7), whereby to increase a flow velocity of the carrier gas (2) and / or to achieve an extended, preferably labyrinthine, flow path (16) of the carrier gas (2) through the at least one filter insert (6) at least one guide device (9) is provided through which the flow path (16) can be deflected, wherein the at least one filter device (1) can be detachably arranged in the oil mist separator (14), a preferably essentially circumferential seal being provided between a first fastening surface of the oil mist separator (14) and a second fastening surface of the filter device (1) to be fastened to it.

is; S.

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DVR 0078018

AT514 708B1 2015-03-15 Austrian patent office

description

The invention relates to an oil mist separator for separating in a carrier gas, in particular crankcase ventilation gas of an internal combustion engine, contained oil with at least one filter device for separating liquid suspended particles from a carrier gas, in particular for separating oil from an oil mist, comprising a housing with at least one inlet opening for introducing the carrier gas and at least one outlet opening for discharging the filtered carrier gas, with at least one filter insert being arranged in the housing through which the carrier gas can flow along a flow direction.

When operating an internal combustion engine, so-called blow-by gases are known to arise, which are to be discharged from a crankcase of the internal combustion engine in order to avoid an increase in pressure in the crankcase and an undesirable leakage of blow-by gas and oil contained therein. In closed crankcase ventilation systems, this crankcase ventilation gas or the carrier gas resulting in the crankcase from the blow-by gases and comprising oil is returned to an air inlet of the internal combustion engine, the pressure in the crankcase usually being kept within predetermined component limit values. However, the carrier gas contains fine oil droplets and solid particles on the order of about 0.1 µm to 10 µm.

In order to avoid negative effects of this oil contained in the carrier gas on components in the air inlet of the internal combustion engine, it is already known to separate the oil and the solid particles from the carrier gas. For this purpose, among other things, filter devices according to the preamble of claim 1 are used, which comprise filter inserts made of a wire mesh or wire mesh through which the carrier gas can flow. However, due to the underlying separation mechanisms and the construction-related structure of such a wire mesh or wire mesh, such filter devices only achieve a limited degree of separation with small droplets or particle sizes (in particular in the grain size range &lt;1 μm). A fine filter (eg coalescer filter) can therefore be used downstream of the filter device, which can filter out smaller oil droplets than the separator.

CN 201198776 (Y) shows an oil mist separator called a crank case ventilation system, consisting of a housing and filter inserts which are arranged between baffle plates. The flow direction of the blow-by gas and the rigid, cast-in arrangement of the baffle plates are unfavorable here.

From JP 2010248934 (A) an oil mist separator with measures for an improved oil separation effect is known.

JP 2001200713 A shows an oil mist separator with a perforated baffle plate.

The object of the invention is to provide a filter device which is improved over the prior art.

According to the invention, this object is achieved by an oil mist separator having the features of claim 1. Advantageous refinements of the invention are given in the dependent claims.

According to the invention it is therefore provided that the at least one filter device can be arranged releasably in the oil mist separator, a preferably substantially circumferential seal being provided between a first fastening surface of the oil mist separator and a second fastening surface of the filter device to be fastened to it.

As a result, bypassing of the filter device by portions of the carrier gas flowing past it can be avoided.

To increase a flow rate of the carrier gas and / or to achieve / 13

AT514 708B1 2015-03-15 Austrian

Patent Office of an extended - preferably labyrinthine - flow path of the carrier gas through the at least one filter insert, at least one guide device is provided through which the flow path can be deflected.

By means of a guide device arranged along the direction of flow, the flow cross-section available to the carrier gas is reduced to a correspondingly reduced cross-sectional area through which the carrier gas can flow. This cross-sectional reduction leads to an increased flow rate of the carrier gas and thus to an increased oil separation in the filter insert. By deflecting the carrier gas at the guide devices, increased oil separation can be brought about, in particular with a correspondingly increased flow rate of the carrier gas - of for example more than 0.9 m / s.

It can preferably be provided that the at least one guide device is designed as a preferably plate-shaped diaphragm. The at least one guide device can be attached to the housing, preferably welded, glued or screwed on, and delimit at least one opening which forms a cross-sectional area through which the carrier gas can flow. The cross-sectional area formed by the at least one opening and through which the carrier gas can flow can, in the case of a plate-shaped diaphragm, run parallel to the plane of the plate. In the case of plate-shaped guide devices in particular, the filter inserts can simply be inserted into the housing and do not necessarily need to be connected or sealed to the housing themselves.

In a preferred embodiment it can be provided that the at least one filter insert is formed from a fabric, braid, knitted fabric, knitted fabric or fleece, which consists of at least one filter wire or at least one filter fiber with a diameter of less than 0.2 mm, preferably smaller 0.1 mm. In the case of small droplets, the degree of separation of the filter insert depends on the diameter of the filter wires or the filter fibers. Small wire or Fiber diameters increase the degree of separation of the filter insert.

It can preferably be provided that a volume fraction of the at least one filter wire or the at least one filter fiber in the filter insert is approximately 2% to 5%, preferably substantially 4%. Depending on the choice of the volume fraction of the filter wires or filter fibers, the degree of separation of the filter insert can be influenced. However, an increased volume fraction will cause an increased pressure loss across the filter insert. It is therefore sensible to take into account any predetermined limit values ​​for a maximum pressure drop through the filter device when dimensioning the volume fraction of the filter wires or filter fibers and when dimensioning the extended flow path caused by the at least one guide device.

A particularly effective separation of oil from a carrier gas can be achieved by the proposed dimensioning of the filter insert. Tests by the applicant have shown that the proposed dimensioning can bring about a high reduction in the oil mass contained in the carrier gas, as a result of which the oil load for downstream fine filters, such as, for example, coalescer filters, can be reduced considerably. This increases the service life of the downstream fine filters, which have to be replaced regularly due to their oil pollution.

According to a particularly preferred embodiment it can be provided that the at least one filter wire or the at least one filter fiber at least partially, preferably essentially completely, consists of metal, preferably of stainless steel or aluminum. In other words, it can be provided that the filter insert is formed from a metal knitted fabric.

A particularly good filter effect can be achieved if an increased flow rate of the carrier gas of at least 0.6 m / s, preferably, of at least 0.6 m / s through suitable dimensioning of the at least one guide device and thus the resulting cross-sectional areas through which the carrier gas can flow in the at least one filter insert

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AT514 708B1 2015-03-15 Austrian patent office at least 0.9 m / s is achieved. The cross-sectional area through which the carrier gas can flow or through which it flows can be a cross-sectional area running transversely to a flow path of the carrier gas through the filter insert, through which the carrier gas can flow through the filter insert.

The increased flow rate of the carrier gas in the filter element caused by the arrangement and dimensioning of the guide devices should, however, be below the so-called flood point of the filter element, i.e. below the speed at which drops are discharged from the filter element.

According to a preferred embodiment it can be provided that a plurality of filter inserts are arranged one behind the other along the direction of flow.

To achieve an extended, preferably labyrinthine, flow path of the carrier gas through the plurality of filter inserts, at least one guide device can be arranged between at least two of the filter inserts arranged one behind the other, preferably between all of the filter inserts arranged one behind the other.

Particularly preferred is that embodiment in which openings delimited by the guide devices are arranged offset from one another, viewed in the direction of flow, the cross-sectional areas formed by the openings through which the carrier gas can flow are preferably substantially the same size. The offset arrangement of the openings of the respective guide devices results in a labyrinth-like structure in relation to the flow path of the carrier gas through the filter device, which accordingly extends the path of the flow path. If the cross-sectional areas that can be flowed through are essentially the same size, a constant flow rate of the carrier gas through the individual filter inserts can be achieved.

Depending on the application, however, it can also be useful to change the cross-sectional areas through which the carrier gas can flow and thus the flow velocity of the carrier gas along the flow path. For example, provision can be made to increase the flow velocity by dimensioning the openings at the transition from the first to the second filter insert (viewed in the direction of flow) and to reduce it again when exiting the second filter insert.

A variant that is particularly easy to manufacture in terms of design can provide that the housing is essentially cuboid, the housing having a length, a width and a height. It can preferably be provided that length to width have a ratio of approximately 1: 1 to 1: 2 and / or length to height have a ratio of approximately 2: 1 to 3: 1. Depending on the application, the housing is more or less equipped with filter inserts. It can thus be provided that the length of the housing has a ratio of approximately 2: 1 to 10: 1 to a total filter element height of all the filter elements located in the housing. In other words, it can certainly be provided that only part of the housing height is actually equipped with filter inserts - preferably starting from the at least one inlet opening of the housing - and the rest of the housing remains empty.

In general, it can be provided that an inlet surface of the at least one inlet opening of the housing transversely to the flow direction and / or cross-sectional areas through which the carrier gas can flow transversely to the flow direction and formed by guide devices at least 10% and / or a maximum of 40%, preferably a maximum of 30%, of a clear Housing cross-section is transverse to the direction of flow or amount. As a result, an increased flow rate of the carrier gas and thus an increased oil separation in the filter insert can be achieved.

It can preferably be provided that the at least one filter device is arranged inclined to the vertical, the direction of flow through the filter device enclosing an angle of about 30 ° to 90 °, preferably essentially 45 °, with the vertical. It is particularly favorable if there is an inlet opening of the filter device in Mon3 / 13

AT514 708B1 2015-03-15 Austrian

Patent Office Tagelage extends at least partially inclined to the vertical, preferably up to a lower end of the filter device with respect to the vertical. The inlet opening can preferably run along a housing wall of the housing of the filter device, a lower edge of the housing wall enclosing an angle of approximately 30 ° to 90 °, preferably essentially 45 °, with the vertical. It can preferably be provided that the guide devices in the filter device are also arranged inclined to the vertical, for example by running parallel to the plane of the inlet opening.

By arranging the filter device of the oil mist separator inclined to the vertical, the specific drainage of the separated oil along the guide devices or diaphragms back to the inlet opening of the filter device on the raw gas side can be achieved. The drainage can take place due to the force of gravity along the guide devices, whereby the drainage behavior can be improved, since the oil return and the gas flow of the carrier gas run separately from one another.

It can preferably be provided that the oil mist separator has a first housing chamber in relation to a flow path of the carrier gas upstream of the at least one filter device, which has an increased free flow area across the flow path of the carrier gas opposite an inlet surface of the at least one inlet opening of the housing of the filter device . It can also be provided that the oil mist separator has a second housing chamber with respect to a flow path of the carrier gas downstream of the at least one filter device, which has an increased free flow area across the flow path of the carrier gas opposite an outlet surface of the at least one outlet opening of the housing of the filter device.

In addition, protection is sought for an internal combustion engine according to claim 19, wherein a proposed secondary oil separator is preferably arranged on the crankcase.

Further details and advantages of the present invention are explained with reference to the following description of the figures. It shows or shows:

1 shows a schematic sectional illustration through a filter device according to the prior art,

2 shows a schematic sectional illustration through an exemplary embodiment of a proposed filter device,

3 shows a view from below of the filter device according to FIG. 2,

4 shows a schematic sectional illustration through a further exemplary embodiment of a proposed filter device,

5 shows a perspective top view of a further exemplary embodiment of a proposed filter device and

6 shows a schematic representation of an internal combustion engine with a proposed oil mist separator which comprises a proposed filter device.

Fig. 1 shows a schematic sectional view of a filter device 1 according to the prior art, comprising a housing 3 and a filter insert 6 arranged in the housing 3. The housing 3 of the filter device 1 has an inlet opening 4 for introducing a carrier gas 2 into the Filter device 1 and an outlet opening 5 for discharging the carrier gas 2 filtered by the filter insert 6 from the filter device 1. The flow of the carrier gas 2 - from which liquid suspended particles such as oil, for example - is to be separated out - through the filter insert 6 along a flow path 16 is indicated by a dashed line. Starting from the inlet opening 4 up to the outlet opening 5, the carrier gas 2 flows through the filter device 1 along a direction of flow 7. In this example, the housing 3 has a direction of flow 7 transverse to the direction of flow 7

AT514 708B1 2015-03-15 Austrian

Patent Office sentlichen rectangular cross-section, so that transversely to the flow direction 7 there is a rectangular, clear housing cross-section 10. The inlet opening 4 of the housing 3 has, transversely to the flow direction 7, a likewise rectangular inlet surface 20 which corresponds to a cross-sectional area 11 through which the carrier gas 2 can flow.

Fig. 2 shows a schematic sectional view through an embodiment of a proposed filter device 1 for separating oil from an oil mist or carrier gas

2. The filter device 1 comprises a housing 3 in which a filter insert 6 is arranged. In this example, the filter insert 6 is formed from a wire mesh made of stainless steel wires, the filter wires 8 of the wire mesh having a wire diameter of less than 0.2 mm, preferably less than 0.1 mm. In this example, the housing 3 has two inlet openings 4, which together form an inlet surface 20 transversely to the flow direction 7, through which the carrier gas 2 can enter the housing 3 and flow through the filter insert 6 along the flow paths 16. Two guide devices 9, which, viewed in the flow direction, are arranged on the housing 3 after the filter insert 6, delimit an opening 12, which in this example corresponds to the outlet opening 5 of the housing 3, through which the carrier gas 2 can exit the filter device 1.

By choosing suitable sizes of the inlet openings 4 and thus by choosing a suitable inlet surface 20, the flow speed of the carrier gas 2 can be influenced, the inlet openings 4 or the inlet surface 20 preferably being selected so that the flow speed of the carrier gas 2 through the filter insert 6 is at least 0.6 m / s, preferably at least 0.9 m / s. The thickness of the filter insert 6 or the distance 25 between inlet openings 4 and guide devices 9, viewed in flow direction 7, is selected in this example so that the resulting cross-sectional area through which carrier gas 2 can flow transversely to flow path 16 through filter insert 6 is essentially half as large as that through the two inlet openings 4 formed entry surface 20. The cross-sectional area 11 formed by the cross-sectional area 11 through which the carrier gas 2 can flow is, in this example, selected to be essentially the same size as the inlet area 20 (formed by the two inlet openings 4), so that an essentially constant flow rate of the carrier gas 2 occurs along the flow paths 16 through the filter insert 6 adjusts.

3 shows a bottom view of the filter device 1 of FIG. 2. As can be seen in this illustration, the base area of ​​the housing 3 of this exemplary embodiment of the filter device 1 has a rectangular design with a length 17 and a width 18. The inlet openings 4, through which the carrier gas 2 can flow into the filter device 1, run in this example along two housing walls 13 of the housing 3 and extend over the entire width 18 of the housing 3. The two inlet openings 4 together form an inlet surface 20, through which the carrier gas 2 can flow into the filter device 1.

4 shows a further exemplary embodiment of a proposed filter device in a schematic sectional illustration. In comparison to the exemplary embodiment in FIG. 2, a plurality of filter inserts 6 are arranged one behind the other in the flow direction 7. Between the filter inserts 6, guide devices 9 are arranged on the housing 3, by means of which the flow paths 16 of the carrier gas 2 flowing through the filter inserts 6 are in each case correspondingly deflected. The guide devices 9 - which are arranged essentially perpendicular to the flow direction 7 - each form openings 12 which, viewed in the flow direction 7, are arranged offset from one another. Overall, this results in a labyrinth-like structure, as a result of which the flow paths 16 are lengthened accordingly. In this example, both all the resulting cross-sectional areas 11 through which the carrier gas 2 can flow and the inlet area 20 of the inlet openings 4 are of essentially the same size, resulting in an essentially constant flow velocity of the carrier gas 2 along a flow path 16. Depending on the application, however, it can also be useful to change the cross-sectional areas 11 through which the carrier gas 2 can flow and thus the flow velocity of the carrier gas 2 along the flow path 16.

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For example, provision can be made to increase the flow velocity by dimensioning the openings 12 at the transition to the second filter insert 6 (viewed in the direction of flow 7) and to reduce it again when exiting the second filter insert 6.

The guide devices 9 between each two filter inserts 6 are arranged in the example shown in the flow direction 7 at a distance 25 on the housing 3. With a suitable choice of inlet area 20, cross-sectional areas 11 through which the carrier gas 2 can flow, and distances 25 between the guide devices 9, the flow velocity of the carrier gas 2 can be influenced for a given volume flow of the carrier gas 2. Depending on the application such as With an internal combustion engine to be equipped with a filter device 1, the structurally particularly easy to influence values ​​for inlet area 20, cross-sectional areas 11 through which carrier gas 2 can flow, and distances 25 can be adapted in order to achieve an optimal filter effect. In particular, by adapting these values, filter devices 1 can be provided for a wide range of different internal combustion engines, which can all have the same external housing dimensions.

FIG. 5 shows a further example of a proposed filter device 1 similar to FIG. 4 in a perspective top view. For the sake of clarity, the filter inserts 6 and a front side wall of the housing 3 have been hidden. As can be seen from the figure, the inlet openings 4 and the openings 12 delimited by the guide devices 9 run essentially along the entire width 18 of the housing 3. The labyrinth-like internal structure of the filter device 1, which is achieved by the guide devices 9, can also be clearly seen.

6 shows a schematic representation of an internal combustion engine 15, on the crankcase 21 of which a proposed oil mist separator 14 with a proposed filter device 1 is arranged. The internal combustion engine 15 can be a gas engine, for example, into which charge air is introduced in a known manner via an air inlet 24. Blow-by gas produced in the crankcase 21 of the internal combustion engine 15 or Carrier gas 2 is fed into the oil mist separator 14. After the oil mist separator 14, which is used as a prefilter, the carrier gas 2 passes into a fine filter 22 in order to remove smaller oil droplets from the carrier gas 2 that cannot be separated by the oil mist separator 14. After the fine filter 22, the carrier gas 2 - via a separate chamber 28 of the oil mist separator 14 - is returned to the air inlet 24 and thus to the charge air. The flow of the carrier gas 2 takes place along this flow path due to the pressure conditions prevailing in the air inlet 24.

A filter device 1 through which the carrier gas 2 flows along a flow direction 7 is arranged in the oil mist separator 14. In this case, an oil contained in the carrier gas 2 is at least partially deposited. With a correspondingly inclined arrangement of the filter device 1, so that the flow direction 7 through the filter device 1 is inclined to the vertical at an angle 23, the oil separated in the filter device 1 can be drained in a targeted manner, for example at one of the inlet openings 4 of the filter device 1. In the example shown, the angle 23 is approximately 45 ° to the vertical.

The oil mist separator 14 shown here has calming zones for the carrier gas 2 in the form of a first housing chamber 26 and a second housing chamber 27 upstream and downstream of the filter device 1. Both the first housing chamber 26 and the second housing chamber 27 each have a compared to the inlet surface 20 of the at least one inlet opening 4 of the filter device 1 or The exit area of ​​the at least one exit opening 5 of the filter device 1 has an increased free flow area transversely to the flow path of the carrier gas 2. Due to the reduced flow speed of the carrier gas 2 in the first housing chamber 26, on the one hand, large oil droplets can be separated from the carrier gas 2 before the filter device 1 and, on the other hand, oil droplets in the second housing chamber 27 after the filter device 1 are not caused by an excessively high flow speed of the carrier gas 2 carried away.

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The carrier gas 2 prefiltered in the oil mist separator 14 is then fed to the fine filter 22, after which it is returned to the air inlet 24 of the internal combustion engine 15 via a third housing chamber 28 of the oil mist separator 14.

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