Oil mist separator for an internal combustion engine

Abstract

Oil mist separator (1) for separating oil (10) from a blow-by gas (G), - with an impactor (20) comprising an impactor housing (2) which at least partially limits a blow-by gas path (3) through which the blow-by gas (G) can flow, wherein the impactor (2) has an impactor plate (4) arranged in the blow-by gas path (3) with through-openings (5) through which the blow-by gas (G) can pass, - with a discharge electrode (6) arranged on the impactor plate (4), which is electrically connected to a high-voltage electrical source (7) during operation of the oil mist separator (1) and generates electrical charge carriers (8) to ionize the oil (10) present in the blow-by gas (G), - wherein the impactor (20) is designed as a precipitation electrode (9) on which oil (10) from the blow-by gas (G) can be or is precipitated during the operation of the oil mist separator (1) and is electrically connected to the electrical high voltage source (7) for this purpose.

Description

[0001] The invention relates to an oil mist separator for an internal combustion engine and to an internal combustion engine with such an oil mist separator.

[0002] During operation of internal combustion engines designed as piston engines, unavoidable leaks between the cylinders and pistons cause exhaust gas from the combustion chambers to enter the crankcase. This exhaust gas is referred to as "blow-by gas". To prevent excessive overpressure in the crankcase, it is common practice to vent the blow-by gas using a process known as crankcase ventilation. An oil mist exists in the crankcase, so the blow-by gas discharged from the crankcase contains oil in the form of small oil droplets. To reduce the oil consumption of the internal combustion engine, it is common practice to separate the oil carried in the blow-by gas using an oil mist separator and return it to the internal combustion engine's oil circuit. The separated oil is usually fed into an oil pan located at the bottom of the crankcase.

[0003] Such an oil mist separator is known, for example, from DE 20 2005 003 462 U1. It describes a blow-by gas path for conveying blow-by gas and an oil separation device arranged in the blow-by gas path for separating oil entrained in the blow-by gas.

[0004] EP 0 685 635 A1 discloses an oil mist separator with an electrostatic precipitator. For this purpose, a high voltage is applied between discharge electrodes and collecting electrodes. In this way, the discharge electrodes generate electrical charge carriers, to which the oil droplets present in the blow-by gas can adhere. The oil droplets thus electrically charged are attracted to the collecting electrodes, allowing them to adhere to them in the form of a precipitate. In addition to such an electrostatic precipitator, another separation unit can be connected in series, which can be designed as an impact separator.

[0005] A problem with conventional oil mist separators with electrostatic precipitators is the risk of arcing due to the high electrical voltage generated between the electrodes. Reducing the high electrical voltage is not effective, as such a reduction would result in unsatisfactory separation results for the oil contained in the blow-by gas.

[0006] It is therefore an object of the present invention to demonstrate new approaches in the development of oil mist separators with electrostatic precipitators. In particular, an oil mist separator is to be created that reduces the risk of electrical flashovers while still achieving good separation results.

[0007] This object is achieved by the subject matter of the independent patent claims. Preferred embodiments are the subject matter of the dependent patent claims.

[0008] The basic idea of ​​the invention is therefore to combine the impactor described above with an electrostatic precipitator, which has a discharge electrode and a collecting electrode, in an oil mist separator. What is essential to the invention is that the collecting electrode is formed by the impactor, i.e. the collecting electrode is integrated into the impactor according to the invention. For this purpose, such a discharge electrode is arranged along a main flow direction of the blow-by gases through the oil mist separator upstream of the impactor plate of the impactor - this is also known to those skilled in the art as a "perforated plate" or "nozzle plate" - which generates electrical charge carriers during operation of the oil mist separator, which in turn ionize the oil droplets. With the help of the discharge electrode, the oil contained in the blow-by gas is electrostatically charged in the form of oil droplets. Typically, said charge carriers are electrons.The discharge electrode is often referred to as a “spray electrode” in technical terms.

[0009] As the gas flow continues, the charged oil droplets in liquid or solid form are attracted and deposited by the collecting electrode. The opposite pole to said discharge electrode, i.e., the collecting electrode, is formed by one or more components of the impactor, in particular the impactor housing, in particular the impactor plate, and a baffle plate arranged downstream of the impactor plate, optionally with an electrically conductive fleece.

[0010] In the impactor, the blow-by gas containing the oil droplets is guided and accelerated through small, nozzle-like openings provided in the impactor plate, causing the oil to hit the collecting electrode at high speed. The charged particles are attracted and separated not only by their inertia but also by their electrical charge, leading to improved separation results.

[0011] Since the discharge electrode is integrated into the impactor, the high electrical voltage between the electrodes can be reduced compared to conventional oil mist separators, thereby reducing the risk of electrical voltage flashovers.

[0012] An oil mist separator according to the invention for separating oil from a blow-by gas comprises an impactor having an impactor housing that at least partially defines a blow-by gas path through which the blow-by gas can flow. The impactor further comprises an impactor plate arranged in the blow-by gas path with through-openings through which the blow-by gas can pass. Preferably, at least one through-opening is nozzle-like; this particularly preferably applies to all through-openings of the impactor plate. In this way, the oil is accelerated so that it can strike the collecting electrode at high speed. A discharge electrode is arranged upstream of the impactor plate, which is electrically connected to a high-voltage electrical source, at least during operation of the oil mist separator.During operation of the oil mist separator, the discharge electrode generates electrical charge carriers to ionize the oil present in the blow-by gas. According to the invention, the collecting electrode is part of the impactor, on which oil contained in the blow-by gas can precipitate during operation of the oil mist separator. For this purpose, the impactor is electrically connected to the high-voltage electrical source. It is understood that the discharge electrode and the collecting electrode are electrically connected to different poles of the high-voltage source. The charge carriers are expediently formed by electrons, i.e., they have a negative electrical charge. Thus, the collecting electrode is expediently connected to a positive electrical pole and the discharge electrode to a negative electrical pole of the high-voltage source.

[0013] According to a preferred embodiment, the impactor plate can be designed to be electrically insulating. Since this embodiment requires no electrical connection between the impactor plate and the high-voltage electrical source, this embodiment is associated with particularly low manufacturing costs.

[0014] According to another preferred embodiment, the impactor plate of the impactor forms the collecting electrode. For this purpose, the impactor plate is electrically conductive and electrically connected to the high-voltage electrical source. This embodiment is particularly simple to implement and thus cost-effective.

[0015] The discharge electrode is conveniently located within the blow-by gas path defined by the impactor housing. This design requires particularly little installation space.

[0016] Particularly preferably, the distance between the discharge electrode and the impactor plate is at most 10 mm, preferably at most 5 mm, most preferably at most 2 mm. In this way, the discharge electrode can generate a high electric field and thus a large number of charge carriers even at a relatively low electrical high voltage.

[0017] According to another preferred embodiment, the impactor comprises an electrically conductive baffle plate arranged downstream of the impactor plate. In this embodiment, the collecting electrode is formed by said baffle plate. For this purpose, the baffle plate is electrically connected to the high-voltage electrical source. In this way, a particularly large amount of oil from the blow-by gas precipitates on the baffle plate during operation of the oil mist separator.

[0018] According to an advantageous development, an electrically conductive fleece can be arranged on the impact plate, preferably on a side of the impact plate facing the discharge electrode. This fleece is connected to the high-voltage electrical source via the impact plate. The fleece can further increase the deposition rate of oil or oil droplets on the impact plate.

[0019] In an alternative embodiment, the fleece can be provided on the impactor plate, preferably on a side of the impactor plate facing away from the discharge electrode. In this variant, the provision of an impact plate can be omitted.

[0020] According to a further advantageous development, the discharge electrode tapers at least partially toward the impactor plate. This achieves particularly high electric field strengths in the area of ​​the discharge electrode, which in turn allows the discharge electrode to generate a particularly large number of charge carriers.

[0021] According to another advantageous development, the discharge electrode is plate-like with tips arranged on the circumference and extends substantially parallel to the impactor plate.

[0022] According to another preferred embodiment, the impactor housing, viewed in longitudinal section along the main flow direction of the blow-by gas, comprises a U-shaped geometry with a base and two legs. In this embodiment, the base is formed by the impactor plate. In this variant, the blow-by path is directly defined by the impactor housing and the impactor plate. This achieves a particularly high effective cross-section while requiring minimal space in the impactor plate.

[0023] The impactor plate or base can be conveniently formed by a (first) housing wall of the impactor housing. This variant requires particularly little installation space.

[0024] According to an advantageous development, the two legs are formed by (second and third) housing walls of the impactor housing. To enable these to function as collecting electrodes, they are electrically conductive and electrically connected to the high-voltage electrical source. Since parts of the impactor housing also act as collecting electrodes in this variant, oil droplets present in the blow-by gas can be separated particularly effectively. This leads to improved efficiency of the oil mist separator.

[0025] According to another preferred embodiment, the discharge electrode protrudes upstream from the impactor plate.

[0026] Particularly useful is the discharge electrode being mechanically connected to the impactor plate or attached to it. This variant is technically particularly simple to implement and therefore cost-effective.

[0027] According to an advantageous development, the impactor plate is designed to be electrically insulating. This variant is particularly easy to manufacture and therefore cost-effective. Alternatively, the impactor plate can be designed to be electrically conductive, but at the same time electrically insulated from the collecting electrode. For this purpose, an electrical insulator can be provided between the collecting electrode and the impactor plate. In this variant, the two electrodes are arranged in close proximity to one another, so that the oil mist separator requires very little installation space. Furthermore, the high electrical voltage between the electrodes can be kept particularly low compared to other variants, since the short distance ensures a high electrical field strength even at a relatively low electrical voltage.

[0028] The discharge electrode advantageously tapers away from the impactor plate, at least in sections. The taper is preferably implemented in an end section facing away from the impactor plate. In this way, electrical charge carriers are emitted from the discharge electrode, which initially move against the main flow direction of the blow-by gas. This achieves a particularly high effective cross section, so that a particularly large number of oil droplets are ionized by the charge carriers, i.e., electrically charged.

[0029] A swirl generator can be conveniently arranged upstream of the discharge electrode and at a distance from it. This ensures that the charge carriers emitted against the main flow direction, if they have not yet encountered and ionized oil droplets, are deflected. After being deflected, they move along the main flow direction toward the collecting electrode, where they can encounter and ionize oil droplets.

[0030] According to an advantageous development, an electrically conductive additional electrode can be arranged in the blow-by gas path upstream of the impactor plate. This serves to modify the electric field generated by the discharge electrode. For this purpose, the additional electrode can be electrically connected to the high-voltage source. By means of the additional electrode, an electric field is generated in the blow-by path, which deflects the electrical charge carriers in such a way that a particularly high effective cross section of the charge carriers with oil is achieved. This ensures that a particularly large proportion of the oil droplets present in the blow-by gas can be ionized by the charge carriers. The additional electrode is expediently connected to the same electrical pole of the high-voltage source as the discharge electrode, preferably to the negative electrical pole of the high-voltage source.

[0031] Particularly preferably, the additional electrode has an annular geometry and a through-opening through which the blow-by gas can flow.

[0032] Particularly preferably, the additional electrode is arranged parallel to and at a distance from the impactor plate.

[0033] According to an advantageous development, a support structure is provided upstream of the impactor plate and at a distance from it, against which the discharge electrode can rest. This allows the discharge electrode to be held mechanically stable to the impactor housing. A particularly stable attachment is achieved by providing an opening in the support structure through which the discharge electrode passes.

[0034] The invention further relates to an internal combustion engine with an oil mist separator as described above. The advantages of the oil mist separator explained above therefore also apply to the internal combustion engine according to the invention.

[0035] Further important features and advantages of the invention emerge from the subclaims, from the drawings and from the associated description of the figures based on the drawings.

[0036] It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present invention.

[0037] Preferred embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description, wherein the same reference numerals refer to the same or similar or functionally identical components.

[0038] They show, schematically: Fig. 1 an embodiment of an oil mist separator according to the invention, Fig. 2 to 4 variants of the example of Fig. 1.

[0039] Fig. 1 illustrates, in a rough schematic and longitudinal section, an example of an oil mist separator 1 according to the invention for separating oil 10 - typically in the form of oil droplets - from a blow-by gas G. The oil mist separator 1 comprises an impactor 20 with an impactor housing 2, which partially delimits a blow-by gas path 3 through which the blow-by gas G can flow. The impactor 20 comprises an impactor plate 4 arranged in the blow-by gas path 3, which has through-openings 5 ​​through which the blow-by gas G can pass. Preferably, at least one through-opening 5 is designed like a nozzle; this particularly preferably applies to all through-openings 5 ​​of the impactor plate 4. In this way, the oil 10 is accelerated as it passes through the through-openings 5.

[0040] Upstream of the impactor plate 4, a discharge electrode 6 is arranged, which is electrically connected to a high-voltage electrical source 7 during operation of the oil mist separator 1 and in this way generates electrical charge carriers 8 for ionizing the oil 10 present in the blow-by gas. The discharge electrode 6 is expediently designed as shown in Fig. 1, the discharge electrode 6 is arranged within a region 14 of the blow-by gas path 3 defined by the impactor housing 2. Furthermore, the discharge electrode 6 can taper at least partially toward the impactor plate 4. This ensures that charge carriers 8 are emitted across the entire blow-by gas path 3. The impactor 20 is designed as a collecting electrode 9, on which oil 10 from the blow-by gas G precipitates during operation of the oil mist separator 1. For this purpose, the impactor 20 is electrically connected to the electrical positive pole 18b of the electrical high-voltage source 7. In the example of Fig. 1, the impactor plate 4 of the impactor 20 is electrically conductive and electrically connected to the high-voltage electrical source 7. It is understood that the discharge electrode 6 and the collecting electrode 9 are electrically connected to different poles 18a, 18b of the high-voltage source 7. The electrical charge carriers 8 are expediently formed by electrons, i.e., they have a negative electrical charge. In this case, the collecting electrode 9 is connected to a positive electrical pole 18b and the discharge electrode 6 to a negative electrical pole 18a of the high-voltage source 7. The impactor plate 4 extends in a plate plane E perpendicular to a main flow direction H of the blow-by gas G along the blow-by gas path 3. In the example of Fig. 1, the impactor plate 4 is formed by a (first) housing wall 11a of the impactor housing 2. In other words, the impactor plate 4 is a part of the impactor housing 2.

[0041] In the Fig. 1 shown longitudinal section along the main flow direction H of the blow-by gas G, the impactor housing 2 has a U-shaped geometry with a base 12 and two legs 13a, 13b. The base 12 is formed by the impactor plate 4 forming the collecting electrode 9 and extends orthogonally to the main flow direction H. The two legs 13a, 13b of the U-shaped geometry are formed by a second and third housing wall 11b, 11c of the impactor housing 2 and extend parallel to the main flow direction H. In the example of Fig. 1, the two legs 13a, 13b, i.e. the second and third housing walls 11b, 11c, are also designed to be electrically conductive to form a collecting electrode 9 and are electrically connected to the positive pole 18b of the electrical high-voltage source 7.

[0042] For oil mist separator 1 according to Fig. 1, the impactor 20 comprises a baffle plate 17 arranged downstream of the impactor plate 4. During operation of the oil mist separator 1, the oil 10 or the oil droplets, after passing through the impactor plate 4, strike the baffle plate 17, where they precipitate. The fleece 15 is also electrically connected to the high-voltage electrical source 7 to form a precipitation electrode 9, but to its electrical negative pole 18a. In this way, the separation rate of oil on the baffle plate 17 is improved. A further improvement in the separation rate can be achieved by arranging an electrically conductive fleece 15 on a side 16 of the baffle plate 17 facing the discharge electrode 9. The fleece 15 is connected to the high-voltage electrical source 7 via the baffle plate 17.

[0043] The Fig. 2 shows a first variant of the example of Fig. 1. In contrast to the example of Fig. 1 is the impactor housing 2 in the example of Fig. 2 is not electrically connected to the high voltage source 7. In the example of Fig. 2, the impactor housing 2 can therefore also be electrically insulating or made of an electrically insulating material. In the example of the Fig. 2, only the impact plate 17 with the electrically conductive fleece 15 is electrically connected to the high voltage source 7.

[0044] How Fig. 2, the discharge electrode 6 can be plate-like with tips arranged on the circumference and extend parallel to the impactor plate 4. In this variant, it proves particularly advantageous if the discharge electrode 6 is arranged at the smallest possible distance from the impactor plate 4. Therefore, a distance a between the discharge electrode 6 and the impactor plate 4 is preferably a maximum of 10 mm, preferably a maximum of 5 mm, most preferably a maximum of 2 mm.

[0045] The Fig. 3 illustrates a second variant of the example of Fig. 1. In contrast to the example of Fig. 1, the impactor plate 4 is designed to be electrically insulating in this variant. The impactor plate 4 is expediently made of an electrically insulating material or comprises at least one electrically conductive material. The first housing wall 11a formed by the impactor plate 4 is therefore designed to be electrically insulating. Naturally, in this variant, there is no electrical connection between the impactor plate 4 and the high-voltage electrical source 7. However, at least the second or the third housing wall 11b, 11c, preferably both the second and the third housing wall 11b, 11c, can be designed to be electrically conductive and electrically connected to the high-voltage source 7, so that the respective housing wall 11b, 11c can act as a collecting electrode 9.

[0046] In the example of Fig. Figure 3 shows an exemplary scenario in which both the second housing wall 11b and the third housing wall 11c are electrically connected to the high-voltage source 7, so that they can act together with the impact plate 17 and the fleece 15 as a collecting electrode 9. In this way, a particularly large proportion of the ionized oil 10 can be deposited on the collecting electrode 9.

[0047] The Fig. 4 shows another variant of the example of Fig. 1. Also in the example of Fig. 4, the impactor plate 4 extends in the plate plane E perpendicular to the main flow direction H of the blow-by gas G. According to the Fig. 4, the discharge electrode 6 protrudes from the impactor plate 4 in the upstream direction, i.e., opposite to the main flow direction H of the blow-by gas G. The discharge electrode 6 is arranged in the area 14 delimited by the impactor housing 2. The discharge electrode 6 can be arranged as shown in Fig. 4, the discharge electrode 6 can be mechanically connected to the impactor plate 4 and also fastened thereto. In this embodiment, the discharge electrode 6 can expediently be designed as a rod with a tip and arranged orthogonally to the impactor plate 4. In the example scenario, the discharge electrode 6 extends parallel to the second and third housing walls 11b, 11c. Particularly expediently, the discharge electrode 6 can be arranged equidistantly and at a distance from the two housing walls 11b, 11c. The impactor housing 2 can also be designed as a tubular body, which is bounded at the end by the impactor plate 4. In this variant, the impactor plate 4 can be designed to be electrically insulating. Alternatively, it is also conceivable to design the impactor plate 4 to be electrically conductive and to connect it to the high-voltage source 7 in the same way as the impact plate 17 with the electrically conductive fleece 15, so that the impactor plate 4 can act as a collecting electrode 9.In this case, the impactor plate 4 must be electrically insulated from the collecting electrode 9 so that the impactor plate 4 and the collecting electrode 9 can be electrically connected to different poles 18a, 18b of the high-voltage source 7. For this purpose, a suitably designed electrical insulation 21 can be provided between the impactor plate 4 and the discharge electrode 9.

[0048] In the example of Fig. 4, the impactor housing 2 is also designed to be electrically insulating, for which purpose the impactor housing 2 may consist of an electrically insulating material or at least comprise such an electrically insulating material.

[0049] In the example of Fig. 4, the discharge electrode 6 tapers away from the impactor plate 4 in an end section 19 facing away from the impactor plate 4.

[0050] How Fig. As illustrated in Figure 4, a swirl generator 11d can be arranged upstream of the discharge electrode 6 and at a distance therefrom, which, as part of the impactor housing 2, delimits the blow-by gas path 3. Preferably, the swirl generator 11d is located opposite the first housing wall 11a along the main flow direction R.

[0051] In the example of Fig. 4, an electrically conductive additional electrode 23 for modifying the electric field generated by the discharge electrode 6 can be arranged in the blow-by gas path 3 upstream of the impactor plate 4. For this purpose, the additional electrode 23 is electrically connected to the high-voltage source 7. The additional electrode 23 encloses a through-opening 24 through which the blow-by gas G can flow and can, for example, have an annular geometry. The additional electrode 23 can expediently be arranged in a plane parallel to and at a distance from the impactor plate 4 or the plate plane E. By means of the additional electrode 23, an electric field is generated in the blow-by path 3, which causes the electrical charge carriers 8 to be deflected in such a way that a particularly high interaction cross section of the charge carriers 8 with the oil 10 is generated. In this way, it is achieved that a particularly large proportion of the oil 10 present in the blow-by gas G is ionized by means of the charge carriers 8.The trajectory of the charge carriers 8 changed by means of the additional electrode 23 is shown in . Fig. 4 by an arcuate dashed line, which is designated by the reference numeral 28.

[0052] Optionally, a mechanical support structure 25 can be provided upstream of the impactor plate 4 and at a distance therefrom, on which the discharge electrode 6 can be supported. For this purpose, the discharge electrode 6 can be arranged as shown in Fig. 4 indicated by an opening 26 provided in the support structure 25.

Claims

[1] Oil mist separator (1) for separating oil (10) from a blow-by gas (G), - with an impactor (20) comprising an impactor housing (2) which at least partially delimits a blow-by gas path (3) through which the blow-by gas (G) can flow, wherein the impactor (2) has an impactor plate (4) arranged in the blow-by gas path (3) with through-openings (5) and through which the blow-by gas (G) can pass, - with a discharge electrode (6) arranged upstream of the impactor plate (4), which is electrically connected to a high-voltage electrical source (7) during operation of the oil mist separator (1) and generates electrical charge carriers (8) for ionising the oil (10) present in the blow-by gas (G), - wherein the impactor (20) is designed as a collecting electrode (9) on which oil (10) from the blow-by gas (G) can or does precipitate during operation of the oil mist separator (1), and for this purpose is electrically connected to the electrical high-voltage source (7). [2] Oil mist separator according to claim 1, characterized by that the impactor plate (4) is electrically insulating. [3] Oil mist separator according to claim 1, characterized by that the impactor plate (4) is designed to be electrically conductive for forming a collecting electrode (9) and is electrically connected to the electrical high-voltage source (7). [4] Oil mist separator according to one of claims 1 to 3, characterized by that the discharge electrode (6) is arranged within the area (14) of the blow-by gas path (3) delimited by the impactor housing (2). [5] Oil mist separator according to one of the preceding claims, characterized bythat a distance (a) between the discharge electrode (6) and the impactor plate (4) is at most 10 mm, preferably at most 5 mm, most preferably at most 2 mm. [6] Oil mist separator according to one of the preceding claims, characterized by that the impactor (2) comprises an electrically conductive impact plate (17) arranged downstream of the impactor plate (4), which is electrically connected to the electrical high-voltage source (7) to form a collecting electrode (9). [7] Oil mist separator according to claim 6, characterized by that an electrically conductive fleece (15) is arranged on the impact plate (17), preferably on a side (16) of the impact plate (17) facing the discharge electrode (6). [8] Oil mist separator according to one of the preceding claims, characterized by that the discharge electrode (6) tapers at least in sections towards the impactor plate (4). [9] Oil mist separator according to one of the preceding claims, characterized by that the discharge electrode (6) is plate-like with tips on the circumference and extends substantially parallel to the impactor plate (4). [10] Oil mist separator according to one of the preceding claims, characterized by in that the impactor housing (2) in the longitudinal section along a main flow direction (H) of the blow-by gas (G) in the blow-by gas path (3) comprises a U-shaped geometry with a base (12) and two legs (13a, 13b), wherein the base is formed by the impactor plate (4) and extends transversely, preferably orthogonally, to the main flow direction (H). [11] Oil mist separator according to claim 10, characterized by that the impactor plate (4) or the base (12) is formed by a (first) housing wall (11a) of the impactor housing (2). [12] Oil mist separator according to claim 10 or 11, characterized bythat the two legs (13a, 13b) are formed by (second and third) housing walls (11b, 11c) of the impactor housing (2), which are designed to be electrically conductive to form a collecting electrode (9) and are electrically connected to the electrical high-voltage source (7). [13] Oil mist separator according to one of the preceding claims, characterized by that the discharge electrode (6) protrudes upstream of the impactor plate (4). [14] Oil mist separator according to claim 13, characterized by that the discharge electrode (6) is mechanically connected to and / or attached to the impactor plate (4). [15] Oil mist separator according to claim 13 or 14, characterized by , that - the impactor plate (4) is electrically insulating, or that - the impactor plate (4) is electrically conductive and is electrically insulated from the collecting electrode (9). [16] Oil mist separator according to one of claims 13 to 15, characterized by that the discharge electrode (6) tapers away from the impactor plate (4) at least in sections, preferably in an end section (19) facing away from the impactor plate (4). [17] Oil mist separator according to one of claims 13 to 16, characterized by that a swirl generator (11d) is arranged upstream of the discharge electrode (6) and at a distance therefrom. [18] Oil mist separator according to one of claims 13 to 17, characterized by that in the blow-by gas path (G) upstream of the impactor plate (4) there is arranged an electrically conductive additional electrode (23) for modifying the electric field generated by the discharge electrode (6), which is electrically connected to the high-voltage source (7). [19] Oil mist separator according to claim 18, characterized bythat the additional electrode (23) encloses a through-opening (24) through which the blow-by gas (G) can flow and preferably has an annular geometry. [20] Oil mist separator according to claim 18 or 19, characterized by that the additional electrode (23) is arranged parallel and at a distance from the impactor plate (4). [21] Oil mist separator according to one of claims 18 to 20, characterized by that upstream of the impactor plate (4) and at a distance therefrom there is a support structure (25) on which the discharge electrode (6) is supported. [22] Internal combustion engine with an oil mist separator (1) according to one of the preceding claims.

Images