WO2017153136A1

WO2017153136A1 - Liquid mist precipitation device

Info

Publication number: WO2017153136A1
Application number: PCT/EP2017/053404
Authority: WO
Inventors: Armando COELHO; Alfred ELSÄSSER; Volker Kirschner; Thomas Riemay; Stefan Ruppel
Original assignee: Mahle International Gmbh
Priority date: 2016-03-08
Filing date: 2017-02-15
Publication date: 2017-09-14
Also published as: DE102016203769A1

Abstract

The invention relates to a liquid mist precipitation device for precipitating liquid from a gas stream (14), in particular for precipitating oil from blow-by gas, comprising a nozzle plate (22), which has at least one nozzle (20) which is at least partially permanently open and through which the gas stream (14) flows, comprising at least one baffle plate (24) which is arranged opposite the at least one nozzle (20) and which deflects the gas stream (14) and on which drops of liquid are deposited. In order to reduce the pressure loss, the liquid mist precipitation device (10) according to the invention has at least one variable nozzle (28) which has a variable nozzle cross-section and is formed between an edge (32) of the nozzle plate (22) and an elastic element (26), and, in the event of rising flow rates of the gas stream (14) through the liquid mist precipitation device (10), at least in a limited range of flow rates a spacing between the elastic element (26) and the edge (32) of the nozzle plate (22) is enlarged.

Description

Flüssigkeitsnebelabscheideeinrichtung

The invention relates to a Flüssigkeitsnebelabscheideeinrichtung for

Depositing liquid from a gas stream, in particular liquid from blow-by gas, with a nozzle plate having at least one nozzle which is at least partially permanently open and through which the gas stream flows, with at least one opposite the at least one nozzle

arranged baffle plate, which deflects the gas flow and on which precipitate liquid droplets, in particular according to the preamble of claim 1.

Such Flüssigkeitsnebelabscheideeinrichtungen based on a

Principle of inertia. The gas flow is accelerated through the nozzles and directed against the baffle plate. At the baffle plate are in the gas stream

entrained liquid droplets driven out of the gas stream due to inertia and hit the baffle plate, where they stick. For an effective liquid mist separation, the

Flow rate of the gas flow through the nozzles should be as high as possible. Therefore, the flow area of the nozzles should not be too large. However, a small flow cross-section causes a high backflow and thus high pressure loss. Here, a compromise of the cross-sectional area makes sense, in which the pressure losses are not too high, but the deposition is sufficient for the system. However, this compromise can always only be optimal for one volume flow.

Therefore, it is known to equip the Flüssigkeitsnebelabscheideeinrichtung with variable nozzles, which have a variable nozzle cross-section, so that at higher flow rates, the total nozzle area can increase and thereby reduce the pressure loss caused.

From DE 10 2006 024 816 A1, for example, a so-called impactor is known. The impactor has a spring-loaded poppet valve, which forms an annular gap when opening and thus forms a variable nozzle.

However, these Flüssigkeitsnebelabscheideeinrichtungen usually have the disadvantage that the gas flow before it flows through the at least one nozzle of the nozzle plate flows and thereby also loses kinetic energy, whereby a pressure loss is generated.

The present invention has for its object to provide an improved or at least other embodiment of a Flüssigkeitsnebelabscheideeinrichtung, in particular by an improved

Liquid separation characterized by lower pressure loss.

This object is achieved by the subject of the independent claim. Advantageous developments are the subject of

dependent claims.

The invention is based on the general idea to form a variable nozzle with variable nozzle cross-section at one edge of the nozzle plate. Thereby, the at least one nozzle of the nozzle plate and the variable nozzle is directed in the same direction, so that the gas flow undergoes fewer deflections, whereby the pressure loss is reduced. According to the invention it is therefore provided that the Flüssigkeitsnebelabscheideeinrichtung has at least one variable nozzle with a variable nozzle cross section, the radial is formed between an edge of the nozzle plate and an elastic member. Thus, the variable nozzle can be easily formed on the edge of the nozzle plate, so that the at least one nozzle and the variable nozzle are aligned in the same direction. Furthermore, the invention provides that with increasing flow rates of the gas stream through the

Flüssigkeitsnebelabscheideeinrichtung enlarged at least in a limited range of flow rates, a distance between the elastic member and the edge of the nozzle plate. As a result, the pressure loss occurring at higher flow rates can be reduced. At the same time can be achieved that even at low flow rates sufficient acceleration of the gas flow takes place in the nozzle, so that a good

Deposition can be achieved.

In the specification and the appended claims, the terms radial, axial and circumferential directions refer to the nozzle plate.

In the description and the appended claims, a nozzle is understood to mean a through-opening, which reduces the size of the nozzle

Flow cross section forms. The passage opening itself can have a constant nozzle cross section. In particular, simple holes in a plate are to be understood as a nozzle. However, the cross-sections of the nozzles are not limited to circles, as in drilling. For example, slit-shaped, annular or arcuate nozzle cross sections are also possible.

A favorable possibility provides that the elastic element in a state of rest, in which the gas flow is not through the Flüssigkeitsnebelabscheideeinrichtung flows against the edge of the nozzle plate. Thus, the variable nozzle is closed at least in the idle state.

Another favorable possibility provides that the elastic element at flow rates below a threshold flow rate at the edge of

Nozzle plate is applied. The threshold flow rate is preferably chosen such that the entire nozzle cross-section of the liquid mist separator is small enough to achieve a sufficient acceleration of the gas flow. At low flow rates, only a small pressure difference builds up, so that it is favorable if below the Schwelldruckdurchflussrate the variable nozzle remains closed, so that at the low flow rates, a sufficient pressure difference for the deposition can be achieved.

Preferably, the elastic element has a modulus of elasticity that is low enough that the elastic element exceeds when the

Threshold rate through the Flüssigkeitsnebelabscheideeinrichtung lifts off the edge of the nozzle plate.

A particularly favorable possibility provides that the elastic element surrounds the nozzle plate, in particular completely encloses. As a result, almost the entire edge of the nozzle plate can be used to form the variable nozzle. Thus, a large variable proportion of the total

Nozzle cross-sectional area of the Flüssigkeitsnebelabscheideeinrichtung be achieved.

An advantageous solution provides that the elastic element is a hose. In the tube, the gas stream may be directed to the nozzle plate, which is preferably inserted into the tube at one end of the tube. Of the Hose can enclose the nozzle plate in this way and pinch in itself. As a result, it can also be achieved that the elastic element, that is to say the hose, only when a threshold flow rate is exceeded and thus when a limiting pressure difference is exceeded, at least

sections from the edge of the nozzle plate lifts and thus opens the variable nozzle.

A further advantageous solution provides that the elastic element is held on an inlet nozzle. Thereby, the gas flow, which is introduced through the inlet port into the Flüssigkeitsnebelabscheideeinrichtung be passed directly through the elastic member to the nozzle plate.

A particularly advantageous solution provides that the elastic element is held on an outer edge of the inlet nozzle. In this way, the elastic element can be easily slipped over the inlet port and thus holds itself firmly to the inlet port. additional

Safety measures such as by gluing or additional jamming from the outside are of course possible.

A favorable variant provides that at the edge of the nozzle plate a plurality of outwardly directed bulges are formed, through which the nozzle plate is braced in the elastic element. Due to the bulges can be achieved that the elastic element does not dissolve over the entire circumference of the nozzle plate. As a result, the nozzle plate can be held in operation by the elastic element. The variable nozzles are then formed between the respective lobes on the edge of the nozzle plate when the elastic element at least partially lifts off from the edge of the nozzle plate. Another favorable variant provides that the variable nozzle is formed as an annular slot. A circular nozzle plate which is clamped in a tube as an elastic member, together with the elastic member generates an annular slit when the elastic member is lifted from the edge of the nozzle plate. In such a case, it is favorable if the

Nozzle plate is held in addition.

A particularly favorable variant provides that the variable nozzle is formed as a slot portion-shaped slot. Such a

arcuate slot can form, for example, between two protrusions which are formed on the edge of the nozzle plate.

Preferably, in such a case at least two, for example, four such variable nozzles are formed with arc-section cross-section.

An advantageous possibility provides that the elastic element a

Having elastomer. Elastomers have a low elastic modulus and at the same time a high elongation at break. As a result, elastomers are well suited to form the elastic element.

A further advantageous possibility provides that the nozzle plate

is held exclusively by the elastic element. As a result, no additional support or connection of the nozzle plate with a part of the housing of the Flüssigkeitsnebelabscheideeinrichtung must be provided, so that the number of components of the Flüssigkeitsnebelabscheideeinrichtung can be reduced. A favorable solution provides that the nozzle plate is connected to the inlet port. In this way, support elements can be avoided, which are downstream of the nozzle and thereby could hinder the liquid separation from the gas stream.

It is advantageous if the nozzle plate and the elastic element are integrally formed with each other. As a result, the nozzle plate and the elastic element can be produced in one work step, for example by

Injection molding. Furthermore, thereby the nozzle plate and the elastic member are firmly connected, so that an additional attachment of the nozzle plate is not necessary.

Another favorable solution provides that the at least one variable nozzle and the at least one nozzle of the nozzle plate into a common

Direction of the nozzle are directed. As a result, the flow of the nozzles can be such that the gas flow in front of the nozzles does not have to be deflected, so that the pressure loss caused can be reduced. Furthermore, can be covered in this way with a single flapper all nozzles and variable nozzles.

A particularly favorable solution provides that the at least one variable nozzle and the at least one nozzle of the nozzle plate are axially directed. This allows a particularly compact design of the

Flüssigkeitsnebelabscheideeinrichtung.

An advantageous variant provides that with respect to each nozzle of the nozzle plate and each variable nozzle, a baffle plate is arranged, which deflects the emerging from the respective nozzle gas flow and at which Beat down liquid drop. It is understood that also one

common baffle plate, which may be provided covering each of the nozzles and each of the variable nozzles. Thereby, the entire gas flow flowing through the nozzles of the liquid mist separator through the

Flap plate to be freed from liquid.

A further advantageous variant provides that the at least one variable nozzle is arranged fluidically parallel to the at least one nozzle of the nozzle plate. In this way, the variable nozzle the

Total flow cross section of the nozzles of

Influence liquid mist separator.

Further, the invention is based on the general idea to provide a variable nozzle with variable nozzle cross-section, which is formed radially between an elastic member and an inner wall of an inlet nozzle and that with increasing flow rates of the gas flow through the

Flüssigkeitsnebelabscheideeinrichtung enlarged at least in a limited range of flow rates, a distance between the elastic member and the inner wall of the inlet nozzle. In this way too, a variable overall nozzle cross-section of the liquid mist separator can be achieved, whereby the backflow can be reduced at high flow rates.

Moreover, the invention is based on the general idea by a spring-loaded pivotable flap which bears against an edge of the nozzle plate to form a nozzle of variable cross-section. According to the invention it is provided that the Flüssigkeitsnebelabscheideeinrichtung has at least one variable nozzle with a variable nozzle cross-section, the side is formed between an edge of the nozzle plate and a spring-loaded flap, and that increases as the flow rates of the gas flow through the Flüssigkeitsnebelabscheideeinrichtung at least in a limited range of flow rates, a distance between the spring-loaded flap and the edge of the nozzle plate.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated

Description of the figures with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

Show, in each case schematically,

Fig. 1 is a sectional view through a

Flüssigkeitsnebelabscheideeinrichtung,

2 is a plan view of a nozzle plate, wherein the elastic element is applied to the nozzle plate, Fig. 3 is a plan view of the nozzle plate of Fig. 2, wherein the elastic

Element is at least partially lifted off the edge of the nozzle plate,

Fig. 4 is a sectional view through a

A liquid mist separator according to a second embodiment of the invention,

Fig. 5 is a sectional view through a

A liquid mist separator according to a third embodiment,

Fig. 6 is a sectional view through a

A liquid mist separator according to a fourth embodiment,

Fig. 7 is a plan view of a nozzle plate according to a fifth

Embodiment of the liquid mist separator,

Fig. 8 is a plan view of the nozzle plate of Fig. 7, wherein a plurality

variable nozzles are extended, and

9 is a sectional view along the section plane A-A of FIG. 7th

A Flüssigkeitsnebelabscheideeinrichtung 10 shown in Fig. 1 is used for example in a crankcase ventilation device to oil or oil mist from blow-by gas, which consists of a crankcase of a

Internal combustion engine is derived, deposit. The Flüssigkeitsnebelabscheideeinrichtung 10 has an inlet port 12, through which a gas stream 14, which is loaded with a liquid mist, can flow into the Flüssigkeitsnebelabscheideeinrichtung 10. Accordingly, the Flüssigkeitsnebelabscheideeinrichtung 10 has an outlet 16, through which the gas stream 14 can flow from the Flüssigkeitsnebelabscheideeinrichtung 10. Furthermore, the liquid mist separator 10 has a liquid outlet 18, through which the liquid, which was separated from the gas stream 14, from the

Flüssigkeitsnebelabscheideeinrichtung 10 can be removed.

For the separation of the liquid from the gas stream 14, the

Flüssigkeitsnebelabscheideeinrichtung 10 at least one, preferably a plurality, for example five, nozzles 20, which are formed in a nozzle plate 22. Opposite the nozzles 20, a baffle plate 24 is arranged, which deflects the gas flow flowing through the nozzles 20 on the baffle plate and thereby causes a liquid separation from the gas stream 14.

Furthermore, an elastic element 26 is provided, which forms at least one variable nozzle 28 together with the nozzle plate 22.

The inlet pipe 12 is for example tubular and has at a lying in the liquid mist separator end of a

Thickening 30 on which the elastic element 26 is held. The elastic element 26 is preferably formed as a piece of hose. Due to the thickening 30 at the inlet connection, the elastic element 26 is held on the inlet connection 12. Additional attachment measures by gluing or clamping from the outside, for example by a hose clamp are of course possible.

The gas stream 14, through the inlet port 12 in the

Flüssigkeitsnebelabscheideeinrichtung 10 flows, flows due to the arrangement of the elastic member 26 into this. Preferably, the elastic member 26 is formed tubular.

At a the inlet nozzle 12 remote from the end of the elastic member 26, the nozzle plate 22 is arranged. The nozzle plate 22 is clamped in the elastic element 26, so that the elastic element 26 encloses an edge 32 of the nozzle plate 22.

Radially between the edge 32 and the elastic member 26 may form a slit-shaped nozzle when due to a pressure difference upstream and downstream of the nozzle plate 22, the elastic member 26 at least partially lifted from the edge 32 of the nozzle plate 22. As a result, the at least one variable nozzle 28 is formed.

The nozzle plate 22 has a plurality, for example four lobes 34, which are directed radially outward and thus expand the elastic member 26 to the outside. In this way, the nozzle plate 22 in the

elastic element 26 clamped. As a result, the nozzle plate 22 can also be held in the elastic element 26 and of the elastic element 26 when the elastic element 26 at least partially lifts off from the edge 32 of the nozzle plate 22. Even in such a case, the elastic member 26 is still at least partially against the bulges 34 of the nozzle plate 22 and thus can hold them. In the area of at least one Such bulge 34 may also optionally be fixedly connected to the elastic member 26, for example by means of an adhesive, welding or vulcanization compound.

The nozzle plate 22 is disc-shaped except for the protrusions 34 and the nozzles 20 formed in the nozzle plate 22, and thus defines an axial direction, a radial direction, and a circumferential direction.

Downstream of the nozzles 20, axially spaced from the nozzle plate 22 is the

Baffle plate 24 is arranged. The baffle plate 24 extends substantially transversely to the axial direction, so that the gas flow, which exits through the axially directed nozzles 20 and the axially directed variable nozzle 28, is deflected at the baffle plate 24.

The gas flow 14, which flows through the inlet port 12, thus can flow through the inlet port 12 axially to the nozzle plate 22 and axially through the nozzle 20 and through the variable nozzle 28 and is only at the

Baffle plate 24 deflected to achieve the liquid separation there. Thus, unnecessary deflections of the gas flow 14 in front of the nozzle plate 22 can be avoided.

In a quiescent state, in which no gas flow 14 or only a relatively small gas flow 14 flows through the liquid mist separator 10 relatively slowly, the elastic element 26 bears against the edge 32 of the nozzle plate 22. Thus, a total nozzle cross section is the

Flüssigkeitsnebelabscheideeinrichtung 10 given solely by the cross-sections of the nozzle 20 of the nozzle plate 22. When a small gas flow 14 flows through the liquid mist separator 10, the back pressure generated by the nozzle plate 22 is small. Therefore, the pressure loss is small, but also the deposition is not optimal, since due to the low back pressure of the gas flow in the nozzles 20 can not be accelerated enough.

With increasing flow rates through the Flüssigkeitsnebelabscheideeinrichtung 10, the back pressure and thus the velocity of the gas stream 14 in the nozzle 20 and thus also the separation effect on the baffle plate 24 increases.

From a threshold flow rate, the velocity of the gas stream 14 in the nozzles 20 is high enough to achieve sufficient liquid separation at the baffle plate. Preferably, it is provided that when the threshold flow rate is exceeded, the elastic element 26 from the edge 32 of

Nozzle plate 22 lifts and thus the variable nozzle 28 opens. This behavior of the elastic element 26 can be achieved by the choice of the corresponding material with a corresponding modulus of elasticity combined with the choice of the wall thickness of the elastic element 26.

By opening the variable nozzle 28 thus increases the

Overall nozzle cross-section of the Flüssigkeitsnebelabscheideeinrichtung 10, when the flow rate continues to increase above the threshold flow rate. In this way, an unnecessary increase in the back pressure can be avoided or at least reduced.

A illustrated in Fig. 4 second embodiment of

The liquid mist separator 10 differs from the first embodiment shown in Figs Flüssigkeitsnebelabscheideeinrichtung 10 in that the nozzle plate 22 is additionally held on a housing 36 of the Flüssigkeitsnebelabscheideeinrichtung 10. As a result, a better fixation of the nozzle plate 22 in the housing 36 of the liquid mist separator 10 can be achieved.

In addition, care must not be taken in the design of the elastic member 26 that the nozzle plate 22 can be held by the elastic member 26.

Preferably, the nozzle plate is connected by an axially directed retaining bolt 38 with a arranged in the inlet port 12 cross member 40th

Incidentally, the second embodiment shown in FIG

Flüssigkeitsnebelabscheideeinrichtung 10 with the in Figs. 1 to 3

illustrated first embodiment of the Flüssigkeitsnebelabscheideeinrichtung 10 in structure and function match, on the above

Description insofar reference is made.

A illustrated in Fig. 5 third embodiment of

The liquid mist separator 10 differs from the first embodiment shown in Figs

Fluid mist separator 10 in that the variable nozzle 28 is not formed on the edge 32 of the nozzle plate, but on an inner surface 42 of the inlet nozzle 12th

The elastic element 26 is designed as an annular lip, which rests peripherally circumferentially on the inner surface 42 of the inlet nozzle 12. With increasing flow rates and thus increased pressure differences thus raises the elastic member 26 of the inner surface 42 of the

Inlet neck 12 and thus opens the variable nozzle 28th

Incidentally, the third embodiment shown in FIG

Flüssigkeitsnebelabscheideeinrichtung 10 with the in Figs. 1 to 3

illustrated embodiment of the Flüssigkeitsnebelabscheideeinrichtung match, to the above description in this respect reference is made.

A fourth embodiment of the invention shown in FIG

The liquid mist separator 10 differs from the first embodiment shown in Figs

Flüssigkeitsnebelabscheideeinrichtung 10 in that the variable nozzle 28 is formed by a spring-loaded flap 44 which rests against an edge 32 of the nozzle plate 22. When the threshold flow rate is exceeded, the flap 44 lifts off from the edge 32 of the nozzle plate 22 and thus opens the variable nozzle 28.

Furthermore, the nozzle plate is held on the inlet port 12. The nozzle plate 22 has a smaller area than the cross-sectional area of the

Inlet neck 12, so that space for the flap 44 is available.

Incidentally, the fourth embodiment shown in FIG. 6 is true

Flüssigkeitsnebelabscheideeinrichtung 10 with the in Figs. 1 to 3

Description insofar reference is made. A fifth embodiment of the liquid mist separator 10 shown in FIGS. 7 to 9 differs from the first embodiment shown in FIGS

Flüssigkeitsnebelabscheideeinrichtung 10 characterized in that the nozzle plate 22 and the elastic member 26 are integrally formed with each other. A

Wall thickness 46 of the nozzle plate 22 is greater than a wall thickness 48 of the elastic member 26. As a result, the nozzle plate 22 remains substantially dimensionally stable, while the elastic member 26 is flexible.

The variable nozzles 28 are formed by slots 50 which are recessed in the material of the nozzle plate 22. At low flow rates, the slots 50 have a non-broadened shape. When the flow rate exceeds a threshold flow rate, the slots 50 widen so that the nozzle area of the variable nozzles 28 increases.

Incidentally, the fifth embodiment of the liquid mist separator 10 shown in FIGS. 7 to 9 is the same as that shown in FIGS. 1 to 3

illustrated first embodiment of the Flüssigkeitsnebelabscheideeinrichtung 10, to the above description in this respect reference is made.

Claims

claims

1 . A liquid mist separator for separating liquid from a gas stream (14), especially oil from blow-by gas,

- With a nozzle plate (22) which has at least one nozzle (20) which is at least partially permanently open and through which the gas stream (14) flows,

with at least one opposite the at least one nozzle (20)

arranged baffle plate (24), which deflects the gas flow (14) and on which precipitate liquid drops,

characterized,

- That the Flüssigkeitsnebelabscheideeinrichtung (10) has at least one variable nozzle (28) with a variable nozzle cross-section which between an edge (32) of the nozzle plate (22) and a

elastic element (26) is formed, and

- That increases in flow rates of the gas flow (14) through the Flüssigkeitsnebelabscheideeinrichtung (10) at least in a limited range of flow rates, a distance between the elastic element (26) and the edge (32) of the nozzle plate (22).

2. Flüssigkeitsnebelabscheideeinrichtung according to claim 1,

characterized, in that the elastic element in (26) rests against the edge (32) of the nozzle plate (22) in a quiescent state in which the gas flow (14) does not flow through the liquid mist separator (10).

3. Flüssigkeitsnebelabscheideeinrichtung according to claim 1 or 2,

characterized,

the elastic element (26) surrounds the nozzle plate (22),

especially completely encloses.

4. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 3, characterized in that

the elastic element (26) is a hose.

5. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 4, characterized

in that the elastic element (26) is held on an inlet pipe (12).

6. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 5, characterized

in that on the edge (32) of the nozzle plate (22) a plurality of outwardly directed bulges (34) are formed, through which the nozzle plate (22) in the elastic element (26) is braced.

7. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 6, characterized in that

- That the variable nozzle (28) is formed as an annular slot, or

- That the variable nozzle (28) is formed as a circular section-shaped slot.

8. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 7, characterized

the elastic element (26) comprises an elastomer.

9. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 8, characterized in that

the nozzle plate (22) is held exclusively by the elastic element (26).

10. Flüssigkeitsnebelabscheideeinrichtung according to any one of claims 1 to 8, characterized

the nozzle plate (22) is connected to the inlet nozzle (12).

1 1. Liquid mist separator according to one of claims 1 to 10, characterized

that the nozzle plate (22) and the elastic element (26) in one piece

are formed to each other.

12. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 1 1, characterized

in that the at least one variable nozzle (28) and the at least one nozzle (20) of the nozzle plate (22) are directed in a common nozzle direction.

13. Flüssigkeitsnebelabscheideeinrichtung according to one of claims 1 to 12, characterized in that

in that, opposite to each nozzle (20) of the nozzle plate (22) and each variable nozzle (28), a baffle plate (24) is arranged, which extends from the respective nozzle (20, 28) deflected gas stream (14) and at which precipitate liquid droplets.

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