DE102021116944A1 - Low-trouble rotating separator with high compatibility for use in fuel cell systems - Google Patents

Abstract

The invention relates to a rotating separator for the continuous processing of fluid flows, in particular in fuel cell systems, comprising: - a housing with a working chamber arranged inside the housing, and - at least one separating element, which is arranged rotatably in the working chamber by means of a holding arrangement, the housing consists at least partially of an electrically conductive plastic with a specific electrical volume resistance of 106Ω m or less, and wherein the holding arrangement consists at least partially of a metallic material with a tensile strength of 800 MPa or more.

Description

The invention relates to a rotating separator for the continuous processing of fluid flows, in particular in fuel cell systems, corresponding fuel cell systems with such a rotating separator and the use of corresponding rotating separators for the continuous processing of multi-phase fluid flows during the operation of fuel cells.

The subject matter of the invention is defined in the appended claims.

The use of fuel cells in the field of vehicle technology has been considered a promising option for reducing dependence on fossil raw materials such as crude oil for several years. The fuel cell represents one of the most important alternatives to the use of batteries, such as lithium-ion batteries. Compared to battery technology, fuel cell technology has specific advantages, especially with regard to the practical handling of the fuel, the storage potential and the refill times as well as the potential Possibility to use the existing line and storage infrastructure.

In fuel cells, oxygen is converted with a fuel, for example hydrogen, methane or methanol, to form water and possibly other reaction products under controlled reaction conditions, with the reaction steps of the redox reaction taking place spatially separately. For this purpose, the fuel cell consists of an anode and a cathode, which are separated from one another by an electrolyte, for example an electrolyte membrane.

The reactants are continuously fed to the fuel cell during operation, with the fuel mostly being used superstoichiometrically. A sophisticated system for the fluid line is therefore necessary for the smooth operation of a fuel cell. In order to ensure the most efficient possible operation of the fuel cell and to ensure high utilization of the materials used, it is particularly necessary to at least partially recirculate the fluid streams exiting the fuel cell, in particular the superstoichiometric fuel used, into the fuel cell. In practice, however, this is associated with considerable problems, in particular because the fluid streams emerging from the fuel cell regularly include the reaction product of the chemical conversion, mostly water, which is at least partially present in condensed form. When recirculating the escaping operating gases, it is usually necessary to avoid that the water generated in the fuel cell and mostly condensed is also fed back into the fuel cell, where otherwise, for example, the fuel cell stack could be flooded unintentionally.

For this reason, a water separator is often used in the fluid line system used for recirculation, or at least in the fluid line system used with the anode.

In the prior art, passive water separators are used for this. According to the inventors, however, these systems can be associated with considerable disadvantages. For example, they can lead to unwanted dynamic pressures or pressure drops in the fluid line system. In particular, when the fuel cell is operated at low load and the fluid flow emerging from the fuel cell stack is therefore comparatively weak, such systems also have poor degrees of separation in relation to the water that has condensed out. In principle, the separation performance of the passive systems known from the prior art is regularly felt to be insufficient.

The inventors of the present invention have now recognized that the problems known from the prior art can be solved by using a rotating separator, which removes condensed by-products from the fluid flow with excellent separation efficiency and, more or less in the manner of a turbine, through its Rotation also actively ensures sufficient flow in the fluid line system.

According to the inventors, the basically advantageous use of rotating separators for the continuous processing of multiphase fluid streams can also be associated with disadvantages which can be regarded as disadvantageous for certain applications, in particular when used in the fluid line system in a fuel cell.

The inventors of the present invention have come to the realization that the rotating separators available from the prior art are in many cases unsuitable for long-term reliable use in fuel cell systems. Fuel cell systems, in particular those that are to be used in vehicles, are regularly highly sensitive systems. Corresponding fuel cell systems can be very susceptible to disturbances, such as unwanted electrical discharges, sudden pressure fluctuations in the line system or the entry of foreign particles into the fuel cell stack.

In contrast to the passive separation systems from the prior art, a failure of the actively working rotating separator and the associated sudden drop in the separation performance can lead to a significant entry of water into the fuel cell stack, which can potentially irreparably damage the fuel cell.

According to the inventors' assessment, the rotating separators known from the prior art are powerful, but when used in fuel cell systems they are also associated with an increased risk of causing corresponding faults in the fuel cell system. This can be done, for example, by the entry of particles generated by wear and the lubricants used. In addition, the active rotating separators are particularly susceptible to static charges, which can endanger the smooth operation of the fuel cell system. In addition, in individual cases, when using rotating separators, sparks can even occur, which should be avoided in a system that works with oxygen and hydrogen, such as the fuel cell.

The object of the present invention was to solve the problems described above and to specify an optimized rotating separator for the continuous treatment of fluid flows for the extremely advantageous and innovative design of the use of a rotating separator in a fuel cell system, which is suitable for the specific requirements of the application is particularly suitable in a fuel cell system.

It was therefore the object of the present invention to specify a rotating separator with a high degree of compatibility for use in fuel cell systems, which enables a corresponding fuel cell system with an active rotating separator to be operated with particularly little disruption and/or little maintenance.

In particular, it was the object of the present invention to reduce the susceptibility of the rotating separator to unwanted electrostatic charging, to minimize the risk of sparking and to reduce the contamination of the downstream fuel cell with particles, for example abrasion, rust and/or lubricants.

It was an additional object of the present invention to design the rotating separator for the continuous processing of fluid flows in such a way that it can be operated reliably at particularly high speeds and particularly high separation rates, in particular over periods of time that correspond to the life expectancy of a fuel cell system used in a vehicle .

A further object of the present invention was to specify a use for corresponding rotating separators for the continuous treatment of multi-phase fluid streams during the operation of fuel cells.

In addition, it was an object of the present invention to specify a fuel cell system which advantageously has a rotating separator, but which should be particularly reliable and easy to operate with little disruption and/or maintenance.

The inventors of the present invention have found during a development project that the objects described above can be achieved by a rotary separator as defined in the claims.

The objects mentioned above are correspondingly solved by rotary separators, uses and fuel cell systems as defined in the claims. Preferred configurations according to the invention result from the dependent claims and the following statements.

Such features of objects according to the invention, which are referred to below as preferred, are combined in particularly preferred embodiments with other features referred to as preferred. Combinations of two or more of the embodiments described below as particularly preferred are therefore very particularly preferred. Also preferred are embodiments in which a feature identified as preferred to some extent is combined with one or more other features identified as preferred to some extent. Features of preferred uses and fuel cell systems result from the features of preferred methods.

• - ein Gehäuse mit einer im Inneren des Gehäuses angeordneten Arbeitskammer, und
• - zumindest ein Abscheideelement, welches mittels einer Halteanordnung rotierbar in der Arbeitskammer angeordnet ist,

wobei das Gehäuse zumindest teilweise aus einem elektrisch leitenden Kunststoff mit einem spezifischen elektrischen Durchgangswiderstand von 10⁶ Ω m oder weniger besteht,
wobei die Halteanordnung zumindest teilweise aus einem metallischen Material mit einer Zugfestigkeit von 800 MPa oder mehr besteht.The invention relates to a rotating separator for the continuous treatment of fluid flows, in particular in fuel cell systems, comprising:

• - a housing with a working chamber arranged inside the housing, and
• - at least one separating element, which is rotatably arranged in the working chamber by means of a holding arrangement,

wherein the housing consists at least partially of an electrically conductive plastic with a specific electrical volume resistance of 10 ⁶ Ω m or less,
wherein the holding arrangement consists at least partially of a metallic material with a tensile strength of 800 MPa or more.

The rotating separator according to the invention is suitable for the continuous processing of fluid flows and, as explained above, is optimized in particular for use in fuel cell systems. Even if the specific properties of the rotating separator according to the invention make it predestined for use in fuel cell systems, the inventors believe that the rotating separator according to the invention is also advantageously suitable for other applications in which a particularly powerful separator is required, but which should be as trouble-free and low-maintenance as possible target.

Rotating separators that can be operated continuously are known in principle to the person skilled in the art from the prior art.

The rotating separator according to the invention comprises a housing with a working chamber arranged inside the housing. This means that the interior of the rotating separator, in which the actual separation of liquid components from the gas phase takes place, is surrounded at least partially, preferably completely except for the inlets and outlets, by a wall structure of the housing.

In addition, the rotating separator according to the invention comprises at least one separating element. This separating element or its rotation in the working chamber is responsible for the high separating effect of the rotating separator.

In order to enable the rotation of the separating element in the working chamber, which supports or conditions the separation, the separating element is arranged in the working chamber so that it can rotate by means of a holding arrangement.

It is essential to the invention that the housing consists at least partially of an electrically conductive plastic with a maximum specific electrical volume resistance. In addition, it is essential to the invention that the holding arrangement consists at least partially of a metallic material with a particularly high tensile strength.

According to the inventors, it is the specific combination of these features that results in a particularly advantageous rotary separator. In particular, unwanted electrostatic charging can advantageously be minimized with such a rotating separator according to the invention. In addition to the surprisingly high level of robustness of the rotating separator obtained, the introduction of foreign particles, which can be caused by abrasion, for example, into the fuel cell is reduced. However, it can be regarded as a very particular advantage of the rotating separator according to the invention that the risk of sparking is minimized in an advantageous manner as a result of the synergistic interaction of the specific features.

The specific electrical volume resistance of materials is a variable that is well known to a person skilled in the art and can be found in relevant tables for most materials. The measurement of the specific electrical volume resistance of other components is carried out in accordance with common practice, either in accordance with DIN EN ISO 3915 from 1999, which is used in particular for particularly conductive materials, or in accordance with IEC 60093 from 1993, which is used for high specific electrical volume resistance is used. The question of which of the two standards is to be used depends on the specifications of the two regulations and the properties of the material being examined.

Analogously to the specific electrical volume resistance, the tensile strength of metallic materials is also a value which the person skilled in the art can take from the relevant tables, for example, or which is usually provided by suppliers of the relevant materials. In addition, the tensile strength can be determined by the specialist himself using a suitable tensile testing machine, in particular in accordance with DIN EN ISO 689-1 from 2020.

Within the scope of the present invention, all material properties, in particular the specific electrical volume resistance, are determined at a temperature of 20.degree.

According to the inventors, it is particularly advantageous if the electrically conductive plastic has a particularly high electrical conductivity and therefore a particularly low specific electrical volume resistance. In this respect, preference is given to a rotating separator according to the invention, the electrically conductive Plastic has a specific electrical volume resistance of 10 ⁵ Ω m or less, preferably 10 ⁴ Ω m or less, particularly preferably 10 ² Ω m or less.

Even if it is in principle possible to assemble the housing from different materials and to use composite materials, the inventors believe that it is particularly advantageous to manufacture the housing as far as possible from the electrically conductive plastic. Preference is therefore given to a rotating separator according to the invention, in which the housing consists of more than 80%, preferably more than 90%, particularly preferably more than 95%, very particularly preferably more than 99%, of the electrically conductive plastic, based on the mass of the case.

With some electrically conductive plastics, it can disadvantageously happen that the housing, which is largely made of these electrically conductive plastics, does not have sufficient strength. To circumvent this problem, the inventors propose that a minimum requirement be made of the tensile strength of the electrically conductive plastic used. A tensile strength of 80 MPa or more has proven to be particularly useful for duroplastics, with the inventors proposing that when using thermoplastics a strength of at least 110 MPa should be set. A rotating separator according to the invention is therefore preferred, in which case the electrically conductive plastic has a tensile strength of 80 MPa or more, preferably 100 MPa or more, particularly preferably 140 MPa or more.

In accordance with the above statements, according to the inventors' assessment, thermoplastics and duroplastics in particular are particularly suitable as electrically conductive plastics. A rotating separator according to the invention is therefore preferred, in which case the electrically conductive plastic is selected from the group consisting of thermoplastics and duroplastics, preferably thermoplastics.

Such electrically conductive plastics can be obtained, for example, by adding electrically conductive additives to plastics that are intrinsically less conductive but have particularly advantageous processing properties. According to the inventors, this specific form of electrically conductive plastics is particularly preferred for rotating separators according to the invention because of their outstanding processing properties. Accordingly, a rotating separator according to the invention is preferred, wherein the electrically conductive plastic comprises one or more electrically conductive additives.

To this extent, the inventors of the present invention have succeeded in identifying particularly suitable plastics with which excellent electrically conductive plastics can be obtained which can be processed into advantageous housings in rotating separators according to the invention. A rotating separator according to the invention is preferred, in which case the electrically conductive plastic is selected from the group consisting of reinforced phenolic resin compositions, polyamides, in particular polyphthalamides, and polyphenylene sulfide.

During the operation of fuel cell systems, particularly when they are used for long periods at high power, particularly high temperatures can very easily occur in the fluids being processed. Accordingly, the inventors of the present invention propose that the electrically conductive plastic for certain applications should not only be optimized in terms of its electrical conductivity and preferably in terms of its tensile strength, but that the selection of the electrically conductive plastic should also be made depending on the glass transition temperature of the plastic . A rotating separator according to the invention is preferred, in which case the electrically conductive plastic has a glass transition temperature of 110° C. or more, preferably 120° C. or more, particularly preferably 130° C. or more.

In fuel cell systems, rotating separators according to the invention work primarily with fluid streams that include water and/or hydrogen. With a view to efficient process management in the fuel cell system and to avoid these components escaping from the fluid line system, the inventors believe it is particularly advantageous to choose the materials of the housing so that they have the lowest possible diffusion coefficient for these components. Without wishing to be bound by this theory, the inventors of the present invention also assume that the lowest possible diffusion of the working fluids into the material of the housing results in particularly long-term durability. Against this background, a rotating separator according to the invention is preferred, the diffusion coefficient of water at 20° C. in the electrically conductive plastic being 10 ^-10 m ² /s or less, preferably 10 ^-12 m ² /s or less, particularly preferably 10 ^-14 m ² / s or less, and / or wherein the diffusion coefficient of hydrogen at 20 ° C in the electrically conductive plastic is 10 ^-5 m ² / s or less, preferably 10 ^-6 m ² / s or less, particularly preferably 5 × 10 ^{- 6} m ² /s or less.

In the light of the above statements and in view of the requirement that the corresponding rotating separators in fuel cell systems in vehicles must be used regularly in wide temperature ranges, the inventors of the present invention propose that the electrically conductive plastic should be selected so that the diffusion coefficient of Water and/or hydrogen changes only slightly with temperature in the expected range of use. A rotating separator according to the invention is preferred, the diffusion coefficient of water and/or hydrogen in the electrically conductive plastic between −40° C. and 120° C. changing by less than 80%, preferably by less than 90%, particularly preferably by less than 99%. differs.

In experiments with rotating separators known from the prior art, it was found that small amounts of recirculated water can lead to unwanted entry of foreign ions into the fuel cell. Without wishing to be bound by this theory, the inventors of the present invention believe that the entrained ions originate from the housings and/or the holding arrangement and have dissolved in the small water droplets carried along with the fluid flow. According to the inventors, this should be largely avoided, which can be achieved in particular by a suitable choice of the plastic of the housing. In particular when using electrically conductive plastics that have been produced by adding additives, it is particularly advantageous to design the material obtained in such a way that it releases essentially no ions into the water when it comes into contact with water, for example by applying a corresponding coating . A rotating separator according to the invention is preferred, in which case the electrically conductive plastic essentially does not release any ions into the water when it comes into contact with water.

For most configurations of the rotating separator it is expedient if the housing and thus the working chamber can be supplied with the fluid to be treated via at least one opening. In addition, the working chamber should have two separate outlet openings, through which the processed gas and the separated liquid phase can be discharged independently from the rotating separator. A rotating separator according to the invention is preferred, wherein the working chamber has at least one inlet opening and at least two outlet openings.

The inventors of the present invention have recognized that comparatively rough components are regularly used in the rotating separators known from the prior art, since the surface quality of the inner walls of the working chamber is not given increased importance in many applications. However, the inventors of the present invention have now recognized that it is particularly advantageous to design the inner walls of the working chamber to be particularly smooth. This initially proved to be advantageous with regard to the water content remaining in the gas phase, which, according to the inventors, is advantageously influenced by reduced condensation in the working chamber. In addition, the inventors of the present invention have also recognized that particularly smooth inner walls of the working chamber prevent the extent of unwanted abrasion, reduce the unwanted absorption of ions from the plastic into the entrained water and improve the oxidation resistance of the surface. Preference is therefore given to a rotating separator according to the invention, the inner walls of the working chamber having an average surface roughness Rz of 10 μm or less, preferably 8 μm or less, particularly preferably 6 μm or less. The average peak-to-valley height Rz is determined in accordance with DIN EN ISO 4287 from 2010 using a 3D profilometer, e.g. a Filmetrics Profilm3D or a Keyence laser profile sensor.

Even if the above teaching can advantageously be used on a large number of rotating separators, for example for flow machines, rotating filters or rotating channel separators, it is nevertheless explicitly preferred if the rotating separator according to the invention is a disc separator. Due to their basic structure, such plate separators are regularly particularly suitable for use in fuel cell systems and are advantageously already fundamentally particularly low in faults and/or maintenance. In addition, plate separators are also preferred because they can usually be operated in a particularly energy-efficient manner. A rotating separator according to the invention is therefore preferred, the rotating separator being a disc separator.

Based on the use of a disk separator for the rotating separator according to the invention, the inventors of the present invention have identified structural configurations of the rotating separator and in particular of the separating element used in it, which, in addition to a particularly advantageous separating performance, have also led to a particularly long service life. For this purpose, the inventors of the present invention propose an optimized distance between the plates of the separating element. Namely, a rotating separator according to the invention is preferred, wherein the separating element has a Arrangement of several plates, wherein the distance between the plates is less than 0.6 mm, preferably less than 0.3 mm, particularly preferably less than 0.2 mm.

In addition to the above statements, the inventors believe that it has proven to be particularly advantageous to produce the plates of the plate separator from a water-repellent material. This has proven to be particularly advantageous with regard to the unwanted entry of ions and/or other foreign particles into the downstream fuel cell. Preference is therefore given to a rotating separator according to the invention, in which the separating element, in particular the discs of a disc separator, consists at least partially of a water-repellent material or is coated with a water-repellent material, with water on the water-repellent material preferably having a contact angle in the range of 70° or more 80° or more, more preferably 90° or more, most preferably 100° or more.

Although high-performance rotating separators according to the present invention can be obtained even with tensile strengths of 800 MPa or more for the metallic material, the inventors of the present invention propose that the tensile strength of the metallic material should advantageously be selected even higher. In the opinion of the inventors, a fundamental improvement of the rotating separator according to the invention is possible with higher tensile strengths, such as can be achieved with alloyed steels, although in practice the necessary material costs will probably be weighed up here. A rotating separator according to the invention is particularly preferred, the metallic material having a tensile strength of 1000 MPa or more, preferably 1100 MPa or more, particularly preferably 1200 MPa or more.

Analogously to the above statements on the smooth surface of the inner walls of the working chamber, it has proven to be advantageous to also design the holding arrangement or the components of the holding arrangement with a particularly smooth surface, with the same measuring specification being able to be used for the determination. In this respect, preference is given to a rotating separator according to the invention, the holding arrangement having an average peak-to-valley height Rz of 10 μm or less, preferably 8 μm or less, particularly preferably 6 μm or less, on the surface.

Similarly to the above statements on the housing, the inventors believe that it is also particularly advantageous if the holding arrangement or the individual components of the holding arrangement consist essentially entirely of the corresponding material. Accordingly, a rotating separator according to the invention is preferred, wherein the holding arrangement consists of more than 80%, preferably more than 90%, particularly preferably more than 95%, very particularly preferably more than 99%, of the metallic material, based on the mass of the holding arrangement.

The inventors of the present invention propose that the holding arrangement in the rotating separator according to the invention expediently comprises a shaft and/or a prestressing spring and/or a bearing, preferably all of these components, with these components of the holding arrangement each as described above as being preferred largely from the should consist of metallic material.

In this respect, preference is given to a rotating separator according to the invention, in which case the holding arrangement comprises at least one shaft, in which case the shaft preferably consists at least partially, particularly preferably essentially completely, of the metallic material.

A rotating separator according to the invention is also preferred, wherein the holding arrangement comprises at least one pretensioning spring, wherein the pretensioning spring preferably consists at least partially, particularly preferably essentially completely, of the metallic material.

A rotating separator according to the invention is also preferred, in which case the holding arrangement comprises at least one bearing, in which case the bearing preferably consists at least partially of the metallic material.

Even if excellent results can be achieved with the rotating separator according to the invention disclosed above when used as a separator in the fluid line system of a fuel cell system, the inventors of the present invention have recognized that the entry of lubricants that serve to lubricate the bearing of the holding arrangement into the fuel cell continues can pose a problem. For this reason, the inventors of the present invention propose using a lubricant-free bearing or a sealed bearing. Advantageously, this configuration can also reduce the contamination in the processed fluid flow, which can be attributed to the use of lubricants in conventional bearings. Preference is therefore given to a rotating separator according to the invention, the bearing being a lubricant-free bearing or a sealed bearing, preferably a double-sealed ball bearing, preferably with at least one sealing element consisting at least partially of a material which is selected from the group consisting of fluorosilicone (FKM) and perfluorocarbon compounds (PFCx), in particular polytetrafluoroethylene (PTFE).

In addition to the structural design of the bearings, the inventors of the present invention also propose certain lubricants which, according to the inventors, have a particularly high level of compatibility with fuel cell systems and which, at least if they only get into the fuel cell in small quantities, cause comparatively little damage there . Preferred therefore is a rotary separator according to the invention, wherein the bearing is a sealed bearing, wherein the sealed bearing comprises a lubricant selected from the group consisting of molybdenum disulfide, PTFE lubricants and graphite.

The invention also relates to the use of a rotating separator according to the invention for the continuous treatment of multi-phase fluid flows during the operation of fuel cells, in particular polymer electrolyte fuel cells.

The invention also relates to a fuel cell system, in particular a polymer electrolyte fuel cell system, comprising a fuel cell, a fluid line system for supplying fluid, in particular for supplying fluid to the anode, a rotating separator according to the invention for the continuous processing of multiphase fluid flows being provided in at least one fluid line.

• 1 eine schematische Darstellung eines erfindungsgemäßen rotierenden Abscheiders in einer besonders bevorzugten Ausführungsform.

The invention and preferred embodiments of the invention are explained and described in more detail below with reference to the attached figure. The figure shows:

• 1 a schematic representation of a rotary separator according to the invention in a particularly preferred embodiment.

1 shows a schematic representation of a rotating separator 10 according to the invention in a particularly preferred embodiment.

The rotating separator 10 is used for the continuous processing of fluid flows and is in the in 1 shown configuration for installation in the fluid line system of a fuel cell system provided with a polymer electrolyte fuel cell. The gas phase stream is 1 indicated with filled-in arrows, whereas the outflow of the separated liquid phase is indicated with an open arrow.

The rotating separator 10 comprises a housing 12. A working chamber 14 is located inside the housing 12. A separating element 16 is arranged in this chamber. The separating element 16 is rotatably suspended in the working chamber 14 by means of a holding arrangement 18, the rotation being caused by a drive 28, which in the present case is designed as an electric motor.

In the illustrated embodiment, the housing consists entirely of an electrically conductive plastic with a specific electrical volume resistance of 100 Ω m. The electrically conductive plastic used has a tensile strength of 120 MPa and is a thermoplastic. The electrically conductive plastic includes the polyamide PA12 and is reinforced with 25% glass fiber.

The glass transition temperature of the electrically conductive plastic is 138 °C. The electrically conductive plastic is selected in such a way that it essentially does not release any ions into the water when it comes into contact with water.

In the 1 illustrated embodiment, the working chamber 14 comprises a total of three openings, namely an inlet opening and two outlet openings. In the exemplary preferred embodiment of the rotary separator 10 according to the invention 1 the inner walls of the working chamber 14 have an average peak-to-valley height of about 5 μm on their surface.

As in 1 As can clearly be seen, the rotating separator 10 according to the invention shown is a disc separator. Correspondingly, the separating element 16 comprises an arrangement of a plurality of plates 20 which, in the embodiment shown here only schematically, have a distance of 0.25 mm from one another.

The rotating separator according to the invention 1 includes a plurality of plates 20 each formed entirely of PTFE. The rotating separator 10 according to the invention also comprises a holding arrangement 18 which, in the embodiment shown here, comprises two bearings 22a, 22b in addition to a shaft 24 which is hollow from the inside and a prestressing spring 26 .

In the exemplary embodiment shown, all of these components consist of a high-strength, high-alloy steel (X46Cr13) with a tensile strength of 1000 MPa. The surface of the individual components of the holding arrangement 18 is particularly smooth in the illustrated embodiment and each has a surface roughness of 4 µm. The bearings 22a, 22b used are double-sealed ball bearings in which molybdenum disulfide is used as a lubricant.

Reference List

10

rotating separator

12

Housing

14

working chamber

16

separating element

18

holding arrangement

20

Plate

22a, 22b

camp

24

Wave

26

bias spring

28

drive

Claims (10)

Rotating separator (10) for the continuous processing of fluid flows, in particular in fuel cell systems, comprising: - a housing (12) with a working chamber (14) arranged inside the housing (12), and - at least one separating element (16) which is The holding arrangement (18) is rotatably arranged in the working chamber (14), the housing (12) consisting at least partially of an electrically conductive plastic with a specific electrical volume resistance of 10 ⁶ Ω m or less, and the holding arrangement (18) at least partly is made of a metallic material with a tensile strength of 800 MPa or more. Rotating separator (10) after claim 1 , wherein the electrically conductive plastic has a specific electrical volume resistance of 10 ⁵ Ω m or less, preferably 10 ⁴ Ω m or less, particularly preferably 10 ² Ω m or less. Rotating separator (10) according to one of Claims 1 or 2 , wherein the electrically conductive plastic has a tensile strength of 80 MPa or more, preferably 100 MPa or more, particularly preferably 140 MPa or more. Rotating separator (10) according to one of Claims 1 until 3 , wherein the inner walls of the working chamber (14) on the surface have an average peak-to-valley height Rz of 10 µm or less, preferably 8 µm or less, particularly preferably 6 µm or less, and/or the holding arrangement (18) on the surface having a average peak-to-valley height Rz of 10 μm or less, preferably 8 μm or less, particularly preferably 6 μm or less. Rotating separator (10) according to one of Claims 1 until 4 , where the rotary separator is a disc separator. Rotating separator (10) according to one of Claims 1 until 5 , wherein the separating element (16), in particular the plates (20) of a plate separator, consists at least partially of a water-repellent material or is coated with a water-repellent material, water forming a contact angle on the water-repellent material in the range of 70° or more, preferably 80 ° or more, more preferably 90° or more, most preferably 100° or more. Rotating separator (10) according to one of Claims 1 until 6 , wherein the holding arrangement (18) comprises at least one bearing (22a, 22b), wherein the bearing (22a, 22b) preferably consists at least partially of the metallic material. Rotating separator (10) after claim 7 , wherein the bearing (22a, 22b) is a lubricant-free bearing or a sealed bearing, preferably a double-sealed ball bearing, preferably with at least one sealing element consisting at least partially of a material selected from the group consisting of fluorosilicone (FKM) and perfluorocarbon compounds (PFCx), in particular polytetrafluoroethylene (PTFE), the bearing (22a, 22b) particularly preferably being a sealed bearing, the sealed bearing comprising a lubricant selected from the group consisting of molybdenum disulfide, PTFE lubricants and graphite. Use of a rotating separator (10) according to one of Claims 1 until 8th for the continuous processing of multi-phase fluid flows during the operation of fuel cells, in particular polymer electrolyte fuel cells. Fuel cell system, in particular polymer electrolyte fuel cell system, comprising a fuel cell, a fluid line system for fluid supply, in particular for fluid supply of the anode, wherein in at least one fluid line a rotating separator (10) according to one of Claims 1 until 8th intended for the continuous processing of multi-phase fluid flows.

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