Separator insert, separator, and method for producing same

Abstract

The invention relates to a separator insert of a centrifugal separator comprising a frame and the separator insert arranged on the frame, wherein the separator insert is designed to separate a free-flowing suspension (S) in a centrifugal field into at least two free-flowing phases (LP, HP) of different densities, and wherein the separator insert has at least the following: a drum (3) having a drum wall made of a plastic material and / or a plastic composite material and a metal coating arranged on the inner face of the drum wall.

Description

[0001] SEPARATOR INSERT, SEPARATOR AND METHOD FOR MANUFACTURING

[0002] The present invention relates to a separator insert, a separator, a method for producing a separator insert and several uses.

[0003] Corrosion and / or wear protection in modern centrifuges is currently ensured primarily by selecting suitable materials for the product-contacting components. When choosing rotating components such as the drum, disc, distributor, and piston valve, a compromise between mechanical strength (centrifugal forces and abrasion) and chemical resistance (corrosion) is always necessary. These properties are often mutually exclusive, meaning that corrosion-resistant materials may have insufficient mechanical strength, or vice versa.

[0004] One proposed solution for corrosion protection of metallic centrifuge drums was, for example, to provide an elastic lining for the product-contacting components of the drum. This is described in DE1 044 723 B. Such a rubber lining can be vulcanized and / or bonded to the metal surface of the centrifuge drum. However, this approach has not proven successful in practice. Among other things, such an elastic lining has a relatively high thickness and weight. Therefore, the uniform weight distribution within the centrifuge drum must be taken into account. Furthermore, additional locking devices are necessary to secure the lining. This demonstrates that it is not easy to reliably implement a corrosion protection measure within a centrifuge drum while considering the high mechanical forces that occur during operation.

[0005] State of the art also includes drums whose inner surfaces are lined with a sheet metal construction (e.g. nickel-based material or titanium) to protect them from corrosion.

[0006] US 2024 / 0238808 A1 discloses a vortex separator with two spatially separated separator chambers. Paragraphs 187 and 188 disclose the protection of a drum by plastic or metal material, in particular stainless steel. However, stainless steel cannot be applied as a coating to the inner wall of a drum by vapor deposition. From this, the person skilled in the art recognizes that linings for corrosion protection are also intended in this document for other materials such as plastic or composite materials.

[0007] German patent DE 10 2020 121 419 A1 discloses a centrifuge with a separator insert that is partially or completely made of a plastic or plastic composite material. Such separator inserts can be used for single-use applications in chemical synthesis, biochemical production, and / or pharmaceutical manufacturing. The separator inserts can be manufactured in multiple parts or as a single piece using injection molding or additive manufacturing processes. The material selection must be tailored to the product being processed. For example, if a solvent such as ethanol or an ethanol / water mixture is used, various plastics may experience dissolution of the plastic wall and / or diffusion into the plastic wall. This can lead to a weakening of the plastic wall through so-called plastic corrosion.However, this is not comparable to the corrosion of metals, which involves the formation of oxide layers, such as rust. Plastic corrosion is based on different chemical degradation mechanisms than metal corrosion. Especially with additive manufacturing processes, only a surface of lower quality is usually achievable. This hinders the further transport of the phases to be separated and can lead to deposits, such as solids, in various areas of the separator insert or the fluid flow within the drum.

[0008] The object of the present invention is therefore to increase the resistance to corrosive, erosive and / or chemically aggressive media in centrifuges with product-contacting components made of plastic or plastic composites.

[0009] This problem is solved by providing a separator insert with the features of claim 1.

[0010] A separator insert according to the invention is intended for use in a centrifugal separator. The centrifugal separator has a frame and the separator insert is arranged on the frame, preferably in a replaceable manner.

[0011] The separator insert, with its rotatably mounted drum, is designed to separate a free-flowing suspension into at least two free-flowing phases of different densities in a centrifugal field. Alternatively or additionally, a solid phase can also be separated, which either remains in the drum or is discharged from it.

[0012] The separator insert according to the invention forms a preferably pre-assembled, interchangeable unit for insertion into stator units on the frame of the separator.

[0013] The separator insert according to the invention comprises at least the following: a rotatably mounted drum with a drum wall made of a plastic and / or a plastic composite material and a metallic coating arranged at least on the inside of the drum wall.

[0014] The drum wall of a centrifuge is subject to particularly high mechanical demands. At the same time, due to the system design, high centrifugal acceleration results in increased medium pressure on the drum wall, thus intensifying the effects of the product or the solvent it contains on the drum wall.

[0015] The metallic coating prevents, among other things, the plastic from dissolving and from leaching into the product. Alternatively or additionally, the metallic coating can improve the surface quality, resulting in better material transport within the drum and also reduced abrasion, for example, from erosive media.

[0016] Finally, the metallic coating can also provide an aseptic and / or antimicrobial surface, e.g. for the processing of products with undesirable biological activity.

[0017] In a preferred embodiment, the average thickness of the metallic coating can be between 0.5 and 100 pm, preferably between 1 and 10 pm. The coating thickness can be determined using a standard commercially available device for measuring coating thickness, e.g., an eddy current thickness gauge. The metallic coating material can advantageously be made of one or more of the following metals: aluminum, nickel, gold, copper, and / or titanium. Gold and titanium are already used in numerous medical applications, e.g., implants and dental fillings, and can be used in the present invention for particularly sensitive products. A coating with aluminum, nickel, or copper represents a significantly more cost-effective option.

[0018] Furthermore, the metallic coating material can, in particular, include or consist of silver. It is possible, among other things, to incorporate silver into another metallic coating material using a vapor composition, thereby increasing its mechanical stability compared to a pure silver layer. Silver enables the biological deactivation of microorganisms in the product being processed. Since the drum typically has a solids collection area, a silver layer can preferably be arranged at least in this area to reduce the microbiological activity of this concentrated phase.

[0019] Preferably, the metallic coating can be directly and metallurgically bonded to the components of the separator insert. In particular, the bonding is achieved solely through this metallurgical bonding without the use of additional locking elements for mechanical fixation of the coating. Even more preferably, the bonding occurs without an additional adhesive layer between the metallic coating and the plastic-containing drum wall.

[0020] Preferably, the plastic and / or plastic composite material of the separator insert components can contain one or more of the following plastic compounds: polystyrene, styrene-acrylonitrile copolymer, and / or polymethyl methacrylate. These can also be used as pure substances, blends, or copolymer components for the production of separator components with product-contacting surfaces.

[0021] Also preferred are plastics that are only conditionally resistant at 50°C – i.e., during the processing of warm products – including polycarbonate and / or polymethylpentene. These can now also be used as pure substances, blends, or copolymer components for the production of separator components with product-contacting surfaces. Freshly produced products from microbiological processes, such as fermentation broths, exhibit an elevated temperature due to the process itself.

[0022] The use of polyamide as a component of the plastic-containing drum material is also preferred. Polyamides are not resistant to some organic acids, such as formic acid, which can form as a byproduct during a microbiological process. Therefore, the class of polyamides, which are very well suited for mechanically stressed separator components due to their material properties, can also be used for the production of the aforementioned separator components.

[0023] Other common organic solvents used in chemical synthesis, or those used to dissolve sparingly soluble or nonpolar synthesis products, such as THF (tetrahydrofuran and hexane), dissolve almost all plastics to a greater or lesser degree. This severely limits the application range of a plastic-containing separator insert. In most cases, the drum wall is not completely dissolved, but rather a small amount of plastic is removed due to brief surface wetting. However, the dissolved plastic contaminates the synthesis product contained in the solvent. The use of a metallic coating enables the contamination-free processing of such solutions with aggressive solvents.

[0024] Preferably, the surface finish of an uncoated area on the drum's outer surface is lower than the surface finish of the coated inner surface. Correspondingly, a higher surface finish reduces the average roughness. This surface modification thus reduces deposit formation within the drum.

[0025] Advantageously, several or all surfaces of the product-contacting components arranged in the separator insert can have the metallic coating. These can include, among others, the surfaces of the following components: drum, separating plate, distributor, peeling disc, inlet pipe, outlet, and housing. This allows the separator insert to be manufactured from a single plastic material or plastic composite material and subsequently provided with the metallic coating, taking into account the intended application. Furthermore, the invention includes a separator with the separator insert according to the invention.

[0026] Furthermore, according to the invention, a method for providing the separator insert according to the invention comprises the following steps:

[0027] A. Providing the separator insert with components made of plastic or a plastic composite material and

[0028] B. Applying the metallic coating by surface vapor deposition to individual or all components from step A.

[0029] The inventive method makes it possible to produce a separator insert with an approximately uniformly distributed metallic coating.

[0030] It is advantageous if the surface vapor deposition is carried out as a vacuum coating or physical surface coating, i.e., as a so-called PVD coating.

[0031] The application process by surface vapor deposition is particularly advantageous if the provision in step A is carried out using additive manufacturing processes.

[0032] Metallic coatings can be used in plastic-containing separators for several reasons, thus generating various advantages. They can serve as a diffusion barrier, particularly for protection against plastic corrosion, for surface smoothing on plastic-containing surfaces of product-contacting components, or as an aseptic and / or antimicrobial coating on plastic-containing surfaces of product-contacting components.

[0033] In a particularly preferred embodiment of the invention, the separator insert according to the invention further comprises: i. a housing that is stationary during operation and is designed in the manner of a container that is closed except for one or more openings; ii. a rotor arranged within the housing and rotatable about an axis of rotation, with a drum which has one or more openings; iii. preferably a separating agent arranged in the drum.

[0034] The invention is described in more detail below with reference to exemplary embodiments and the drawing, and further advantageous variants and embodiments are also discussed. It should be emphasized that the exemplary embodiments discussed below are not intended to provide an exhaustive description of the invention, but that variants and equivalents not shown are also feasible and fall within the scope of the claims. The drawing shows:

[0035] Figure 1: a schematic, cross-sectional representation of a first interchangeable separator insert of a separator together with a schematic representation of an inlet and outlet system and a control unit of the separator;

[0036] Figure 1 shows an assembly of a separator with a reusable frame and with an interchangeable separator insert II for centrifugal separation of a product - a suspension S - into different dense phases HP, LP.

[0037] Separator insert II is preferably designed as a prefabricated unit. In particular, separator insert II is designed as a disposable separator insert that can be replaced or exchanged as a whole and is designed as a pre-assembled unit, and which is made entirely or predominantly of plastic or plastic composite materials.

[0038] The separator insert (which does not include elements a and 5a) is shown separately as an example in Figure 1. It can be disposed of after processing a batch of product and replaced with a new separator insert II.

[0039] According to Fig. 1, the separator insert II of the separator comprises a housing 1 and the rotor 2, which is inserted into the housing 1 and rotatable relative to the housing 1 during operation. The rotor 2 has an axis of rotation D. This can be oriented vertically, which corresponds to the design of the frame I. However, it can also be oriented differently in space if the frame is designed accordingly.

[0040] The rotor 2 of the separator insert II has a rotatable drum 3. The rotor 2 is rotatably mounted at two locations axially spaced apart from each other in the direction of the axis of rotation, each with its own magnetic bearing assembly 4, 5. Preferably, the rotor 2, and consequently the drum 3, is rotatably mounted at both axial ends. The separator insert II has rotor units 4b, 5b of the magnetic bearing assemblies 4, 5. Stator units 4a, 5a of the magnetic bearing assemblies 4, 5 are arranged on the frame 1-1.

[0041] The magnetic bearing devices 4, 5 preferably act radially and axially and hold the rotatably mounted rotor 2 preferably in the housing 1 at a distance from it in suspension.

[0042] Such a separator with an easily replaceable separator insert can be useful and advantageous in the processing of products where it can be ruled out with a very high degree of certainty that impurities will be introduced into the product – a flowable suspension or its phases – during centrifugal processing, or where cleaning and disinfection of the separator would be very complex or even impossible.

[0043] A suitable frame is illustrated, inter alia, in EP 4 196 284. It has a console. This can be mounted on a carriage with rollers. Receptacles can be formed on the console, which serve to receive and hold the separator insert II, even during operation. Preferably, a first axial end of the separator insert II projects from below into or towards the upper receptacle, and a lower end of the separator insert II projects from above into or towards the other receptacle, whereby the separator insert II is held against rotation on the console and thus on the frame.

[0044] One or both of the mounting points can be arranged laterally on the frame, particularly the console. In one variant, the lower mounting point can be fixed to the console. In this case, it is advantageous for the upper mounting point to be height-adjustable on the console.

[0045] It is intended that the relative distance of the mounts with the stator units 4a, 4b of the bearing devices 4, 5 is adjustable in order to be able to change the separator insert II.

[0046] The respective stator units 4a, 5a of two drive and magnetic bearing units 4 and 5 can be arranged in the respective mountings. The control and power electronics for these can be arranged in or on the frame, e.g. in, on or above the console.

[0047] Corresponding positive locking elements can be provided on the mountings and on a housing 1 of the separator insert II that does not rotate during operation, in order to enable the separator insert II to be inserted into the stator units 4a, 5a in a rotationally fixed manner. The upper and lower stator units 4a, 5a can each have axes aligned with each other.

[0048] The housing 1 preferably consists of a plastic or a plastic composite material. The housing 1 can be cylindrical and have a cylindrical outer shell, at the ends of which two radially extending boundary walls (lid and base) are formed.

[0049] The drum 3 serves for the centrifugal separation of a flowable suspension S in the centrifugal field into at least two phases LP, HP of different densities, which can be, for example, a lighter liquid phase and a heavier solid phase or a heavier liquid phase.

[0050] In a preferred embodiment, the rotor 2 and its drum 3 have a vertical axis of rotation D. However, the housing 1 and the rotor 2 could also be oriented differently in space. The following description refers to the vertical orientation shown. With a different orientation in space, the orientations change accordingly. In addition, one or both outlets may be arranged differently – to be discussed further.

[0051] The rotor 2 of the separator with the drum 3 preferably consists entirely or predominantly of a plastic material or a plastic composite material.

[0052] The drum 3 is preferably designed to be cylindrical and / or conical, at least in sections. The same applies to the other elements in the rotor 2 and on the housing 1 (except for elements of the magnetic bearing devices 4, 5).

[0053] The housing 1 is designed in the manner of a container, which is advantageously hermetically sealed except for a few openings / opening areas (to be discussed later). According to Fig. 1, one of the openings is formed in each of the two axial boundary walls of the container 1, which are shown here as the top and bottom.

[0054] One of the openings - in the first, here upper axial boundary wall - enables or serves, according to Fig. 1, as an inlet 8 for feeding a suspension to be separated in the centrifugal field into at least two phases of different density - LP and HP - through the housing 1 into the drum 3.

[0055] Here, the first phase is a lighter phase LP and the second phase is a denser, heavier phase HP compared to the first phase.

[0056] A second of the openings - in the second, here lower axial boundary wall 7 - allows or serves as a drain for the second heavier phase HP directly from the drum 3 through the housing 1.

[0057] The drum 3 also has openings that correspond to the openings of the housing. A feed pipe 12 for a suspension to be processed extends into an upper opening 12a at one axial end of the drum 3. This pipe passes through the housing 1, in particular through one of its axial boundary walls – in this case, the upper one. The feed pipe 12 is sealed to the housing 1 at its outer circumference, as shown in Fig. 1, and is inserted into the housing 1 – for example, by welding or bonding – or optionally formed integrally with the housing as an injection-molded plastic part. It is preferably also made of plastic. One end of the feed pipe 1 protrudes outwards from the top of the housing 1 and extends through the upper boundary wall into the drum 3, without touching the drum 3.

[0058] The inlet pipe 12, as shown in Fig. 1, passes concentrically to the axis of rotation of the rotor 2 through the housing 1 and one magnetic bearing 4, then extends axially further inside the housing 1 into the rotatable drum 3 and ends there with its other end - a free outlet end.

[0059] The inlet pipe 12 opens into the drum 3 into a distributor 13, which is rotatable with the drum 3, as shown in Fig. 1. The distributor 13 has a tubular distributor shaft 14 and a distributor base 15. One or more distributor channels 16 are formed in the distributor base 15. A stack of separating plates, in this case conical, 17, can be mounted on the distributor 13. The distributor 13 and the separating plates 17 are preferably also made of plastic. Furthermore, as shown in Fig. 1, a first peeling disc 33 serves to discharge the heavier phase HP of the two phases HP and LP from the drum 3. A peeling disc shaft or a central discharge pipe 34 passes through the second axial boundary wall 7 (see Fig. 1).

[0060] In one possible – but not mandatory – embodiment, the drum 3 has at least two cylindrical sections 18, 19 of different diameters. Adjacent to these, one or more conical transition regions may be formed on the drum 3. The drum 3 may also be generally single or double conical in its central axial region (not shown here).

[0061] As shown, the drum 3 can have a lower cylindrical section 20 of smaller diameter, on / in which the rotor unit 5b of the lower magnetic bearing is also formed, which transitions into a conical area 20a, then here, for example, a cylindrical area 19 of larger diameter, then again a conical area 18a and then an upper cylindrical section 18 of smaller diameter, on which the rotor unit 4b of the upper magnetic bearing 4 is formed.

[0062] With regard to the removal of the lighter phase, the separator inserts of Fig. 1 differed.

[0063] In one embodiment, openings can also be provided, which can be distributed circumferentially on the drum 3, with several openings being provided on each drum 3. According to Fig. 1, these serve as radial or tangential outlets 21 for the lighter phase LP from the drum 3. An opening in the outer casing of the housing then allows, according to the embodiment shown in Fig. 1, the outlet or serves as a drain 10 for the lighter product phase LP formed during centrifugal separation, which has been discharged from the drum 3.

[0064] The first outlets 21 on the radius ro of the drum 3 are designed as nozzle-like openings in the outer shell of the drum 3. They are also designed as so-called "free" outlets from the drum 3. These first outlets 21 serve to discharge the lighter phase LP. The outlets can be designed so that the lighter phase exits radially, or alternatively, they can be shaped so that the lighter phase exits tangentially against the direction of rotation of the drum, thus contributing to the drive of the rotor and reducing the drive energy. This phase exiting the drum 3 is collected in the housing 1 in an upper annular chamber 23. This annular chamber 23 is designed such that the phase collected within it is directed to the outlet 10 of the annular chamber 23. This is achieved by positioning the outlet 10 at the lowest point of the annular chamber 23.The collecting ring chamber 23 is open radially inwards towards the rotating drum 3 and is designed such that liquid ejected from the respective outlet 21 during centrifugal separation is essentially only injected into the associated collecting ring chamber 23, which lies at the same axial level.

[0065] Below the annular chamber 23, a chamber 25, not used for phase discharge, can optionally be provided. This chamber 25 can optionally have a leakage drain (not shown here). The leakage can drain freely, preferably into a container. However, it can also be extracted by negative pressure if the chamber 25 has a negative pressure connection for connecting a negative pressure generating device.

[0066] The first trap ring chamber 23 and the chamber 25 can be separated from each other by a first conical wall 26, which extends conically inwards and upwards from the outer shell of the housing 1 and ends radially in front of the drum 3, spaced apart on the inside.

[0067] Preferably at the lowest point of the collecting ring chamber, the product phase LP is discharged from the housing 1 through the outlet 10. Connections can be provided on the outside of the housing 1 in the area of ​​the outlet 10 to allow for easy connection of pipes, hoses, and the like.

[0068] These components can be directly integrated into the housing 1 or attached to it by adhesive bonding. The nozzles are preferably also made of plastic. The housing 1 can be composed of several plastic parts that are sealed together, for example, by adhesive bonding or welding.

[0069] As the (here second) outlet for the heavier phase HP from the drum (through the housing 1), the first peeling disc 33 is provided according to Fig. 1. This disc extends essentially radially and transitions into an axially extending discharge tube 34, which serves as the peeling disc shaft and penetrates the lower axial boundary wall 7 of the housing 1. The peeling disc 33 has an outer diameter ru, where ru > ro. The inlet openings 33a of the peeling disc 33 are therefore located on a larger diameter or radius ru than the outlets 21 for the lighter phase LP on radius ro. This makes it possible to discharge a phase HP, which is heavier relative to the lighter phase LP, from the drum 3 using the peeling disc 33. During operation of the separator, the peeling disc 33 remains stationary and its outer edge is immersed in the heavier phase HP rotating in the drum 3.

[0070] The channels in the peeling disc 33 direct the HP phase inwards. The peeling disc 33 thus serves to direct the HP phase in the manner of a centripetal pump.

[0071] The peeling disc 33 can be arranged in a simple and compact manner in the drum 3 below the distributor 14 and below the plate pack 17. The radius ru corresponds to the immersion depth of the peeling disc 33.

[0072] The drain pipe 34 extends downwards from the housing 1 and through the lower boundary wall 7 at one end, without touching the drum 3. The drain pipe 34 can be formed integrally with the housing 1 or be sealed within it. A hose or similar component can be connected to the drain pipe as a drain 35.

[0073] The discharge tube passes concentrically to the axis of rotation D of the rotor 2 through the housing 1 and the lower magnetic bearing 5, and then extends axially further within the housing 1 into the peeling disc 33.

[0074] It can be provided that a controllable, especially electrically controllable, control valve 36 is installed in the outlet for the heavy phase HP, in particular in the branch 35 for the heavier phase HP. The control valve 36 can throttle the volume flow of the heavy phase HP in the branch 35 and increase the immersion depth of the associated peeling disc. A control device 37 is preferably provided. The control valve 36 is preferably wirelessly or wired connected to the control device 37. The control device 37 can also be designed and provided for controlling the magnetic bearings 4, 5 and the drive.

[0075] Theoretically, a third peeling disc could also be provided, which could serve to derive a further phase.

[0076] The operation of the separator according to Fig. 1 is briefly described below.

[0077] First, the respective separator with its reusable components is provided. This includes the frame I and the drive and stator units 4a and 5a of the magnetic bearing devices. A control unit 37 is also included. Next, a separator insert II is provided and mounted on the frame I. This only requires moving the stator units 4a and 5a apart. The separator insert is then positively engaged, and the stator units are moved towards each other. This securely holds the housing in a rotationally fixed position. Finally, hoses are connected to the ports, if necessary, leading into tanks or bags. The respective separator insert in Fig. 1 can therefore preferably also have hoses and ports that can be connected to (not shown here) other lines and containers such as bags, tanks, pumps, and the like.

[0078] Then, after connecting the lines, hoses, etc., a suspension is fed into the rotating drum (inlet 8) and there centrifugally separated into the light phase LP and the heavy phase HP.

[0079] The heavier phase HP, with its higher density, flows radially outwards in the separation chamber of the drum 3. There, the phase HP leaves the drum at a radius ru through the channels of the stationary peeling disc 33.

[0080] The lighter phase LP flows radially inwards in the separation chamber of the drum 3 and rises upwards through a channel 38 on a shaft of the distributor. There, the phase LP leaves the drum, as shown in Fig. 1, on a radius ro.

[0081] The control valve 36 allows for easy influence on the separation process, resulting in optimized separation. The primary application of the separator according to the invention is cell separation in the pharmaceutical industry. Its capacity is designed for processing broths from fermenters ranging from 100 to 4000 liters, as well as for laboratory applications.

[0082] Other industrial sectors where separators are used are also conceivable: chemicals, pharmaceuticals, dairy technology, renewable raw materials, oil and gas, beverage technology, mineral oil, etc.

[0083] The separators shown enable the production of a separator insert in which preferably all product-contacting components can be made of plastic or other non-magnetic materials that can be disposed of or recycled after a single use. Cleaning after use is therefore unnecessary. The separator and its operation can thus be implemented cost-effectively.

[0084] Disposable separator inserts of the type described above are typically used in the pharmaceutical industry and / or possibly also in the food industry and / or possibly also in biochemistry.

[0085] Metallic inner coatings for drum 3 are suitable for various applications. In the field of large centrifuges with stainless steel drums, sheets have previously been formed as a corrosion-resistant layer and sealed to the inside of the drum in a medium-tight manner. This process is correspondingly complex.

[0086] In the much newer area of ​​separator inserts made of plastic or plastic composite material, corrosion protection is not necessary.

[0087] However, depending on the nutrient solution or solvent used, an interaction can occur between the plastic wall or the plastic composite wall of the drum 3. Due to centrifugal forces and the intensive contact of the product with the drum wall, diffusion effects into the plastic, swelling of the plastic, partial dissolution of the plastic, plastic corrosion, and / or embrittlement of the plastic of the drum wall can also occur. To prevent these effects, the drum wall has a metallic coating 39. The metal coating 39 is preferably arranged such that all product-contacting inner surfaces of the drum wall are provided with a metal coating 39. The metal coating 39 acts as a separating layer between the plastic material or plastic composite material of the drum wall and the product.

[0088] Advantageously, individual or all surfaces of the product-contacting components arranged in the separator insert can have the metallic coating (not shown). Examples include the surfaces of the following components: drum 3, separating plate 17, distributor 13, peeling disc 33, inlet pipe 12, outlet 10, discharge pipe 34, and housing. This allows the separator insert as a whole, or the individual components, to be manufactured from a single plastic material or plastic composite material and subsequently coated with the metallic material, taking into account the intended application.

[0089] Alternatively or additionally to its function as a separating layer, the metal coating 39 can also be designed as an antimicrobial layer, which reduces the bacterial load during processing and minimizes the transfer of bacteria into the respective separated phases. Such a metal layer could, for example, be a silver coating.

[0090] For disposable separator inserts, their components can be manufactured, for example, using additive manufacturing processes, preferably in one piece. These manufacturing processes typically produce surfaces with low surface quality. An applied metal layer can therefore compensate for surface irregularities, resulting in an improvement in surface quality compared to the uncoated drum.

[0091] Possible preferred coating materials for metal coating include gold, silver, copper, nickel, titanium and / or aluminium.

[0092] The metal coating can be achieved by vapor deposition, preferably by vacuum coating or by a PVD (physical vapor deposition) process. The aforementioned process allows a thin metal layer to be applied to the plastic surface. The preferred layer thickness can be more than 0.5 µm and less than 100 µm, preferably between 1 and 10 µm.

[0093] Metallic vapor deposition offers a simple and proven method for coating product-contacting surfaces. This allows for the production of components for separator applications with surface finishes unattainable through injection molding or 3D printing. This prevents the formation of deposits, for example, on the inner surface of the drum, and facilitates more targeted transport to the concentration and / or discharge points. Furthermore, the coated surfaces are protected from products, i.e., corrosive or chemically aggressive media, to which they are exposed. This prevents, for example, swelling of the plastic, chemical dissolution, embrittlement, discoloration, or similar issues.

[0094] Metallic vapor deposition can thus be used to achieve surface finishing, corrosion protection against plastic corrosion and / or wear protection through a materially bonded, corrosion-resistant metallic coating.

[0095] Furthermore, during the steam coating process, not only the inside of the drum wall but also other product-contacting plastic parts of the separator insert can be easily coated with a metallic layer. These parts are used in the centrifuge drum, the inlet and / or outlet system. This results in a material-bonded connection.

[0096] The vapor deposition process is precise and enables a uniform coating even with complex geometries.

[0097] Preferably, the metallic layer can be a functional coating that goes beyond the protective effect of the drum wall.

[0098] Surface quality can be improved if the drum wall cannot be manufactured to the required quality or surface roughness using injection molding or 3D printing. In this configuration, the coated drum wall can also be protected from the products to which it is exposed. Furthermore, an aseptic and / or antimicrobial effect can be achieved through silver vapor deposition. Silver releases ions that interact with the cell walls of microorganisms such as bacteria, viruses, and fungi. These ions disrupt vital functions such as cellular respiration and protein synthesis, leading to the death of the microorganisms. If microorganisms are collected as solids in a section of drum 3, they are inactive or killed and therefore no longer affect product quality. Silver has a broad spectrum of activity and is particularly advantageous because it is also effective against antibiotic-resistant microorganisms.Its efficacy and stability make it ideal for use in the medical and / or pharmaceutical fields. It is also relatively gentle on human cells.

[0099] Plastic components, in particular the inner surface of the drum wall of drum 3, typically do not have a completely closed surface, but rather exhibit microscopic irregularities or pores that can allow the penetration of liquids, gases, or particles. The size and number of these pores depend on the type of plastic and its processing. For example, porous structures can arise from injection molding, extrusion, or uneven curing. Metallic coating, such as by physical vapor deposition (PVD), can at least partially close such pores. In this process, a thin metal layer is applied to the plastic surface, filling in irregularities and smoothing the surface. Under ideal conditions, metallic layers can reduce porosity and almost completely seal the surface (diffusion barrier).

[0100] The layer thickness is controlled by the vaporization duration and the amount of material vaporized.

[0101] Furthermore, the metallic coating allows for a significantly smoother surface than that of the original plastic component (e.g., the separator plate). This considerably improves the sliding properties of the surfaces involved in the separation process, thereby enhancing the separation of solids, such as germs, from a suspension. Adhesion to the surfaces is also reduced, allowing single-use components to retain their original properties for longer and multi-use components to be used for a longer period before cleaning is required.

[0102] Metallic vapor deposition prevents direct contact between the plastic used in the drum, which is responsible for the component's mechanical stability, and the product being processed. This also gives the designer significantly more freedom in selecting the plastic to be used. For example, a polyamide can be used, which has good manufacturing properties and stability, but in many cases is not diffusion-tight or solvent-resistant.

[0103] Furthermore, the rotating drum confines a single separator chamber over more than 90% of its axial extent. Multiple separator chambers, such as those described in US 2024 / 0238808 A1, with a movable partition, are difficult to seal against each other with a coating and can also be mechanically damaged by the partition.

[0104] Furthermore, the separator according to the invention can advantageously include a separating agent, in particular a separating plate assembly, which is spaced away from the drum wall to improve the separation efficiency, so that a gap, in particular a distributor gap, is provided between the separating agent and the drum wall.

[0105] Furthermore, the rotating drum can be directly surrounded by a non-rotating housing.

[0106] Reference sign

[0107] 11 Separator insert

[0108] 1 case

[0109] 2 Rotor

[0110] 3 Drum

[0111] 4.5 Magnetic storage device

[0112] 4a, 5a Rotor unit

[0113] 4b, 5b Rotor unit

[0114] 7 Boundary wall

[0115] 8 Inlet

[0116] 10 Procedure

[0117] 12 Inlet pipe

[0118] 12a Opening

[0119] 13 distributors

[0120] 14 distribution

[0121] 15 distributor foot

[0122] 16 distribution channels

[0123] 17 separating plates

[0124] 18, 19, 20 cylindrical sections

[0125] 18a conical area

[0126] Section 20

[0127] 20a conical area

[0128] 21 outlets

[0129] 23 Catch ring chamber

[0130] 25th Chamber

[0131] 26 conical wall

[0132] 33 peeling disc

[0133] 33a Inlet opening

[0134] 3 Drainage pipe

[0135] 35 Derivative

[0136] 36 Control valve

[0137] 37 Control unit

[0138] 38-channel

[0139] 39 Coating

Claims

Claims 1. Separator insert of a centrifugal separator with a frame and the separator insert arranged on the frame, wherein the separator insert is designed to separate a flowable suspension (S) in a centrifugal field into at least two flowable phases (LP, HP) of different densities, characterized in that the separator insert comprises at least the following: a rotatably mounted drum (3) with a drum wall made of a plastic and / or a plastic composite material and a metallic coating arranged on the inside of the drum wall.

2. Separator insert according to claim 1, characterized in that the average layer thickness of the metallic coating is between 0.5-100 pm, preferably between 1-10 pm.

3. Separator insert according to claim 1 or 2, characterized in that the metallic coating material is formed from one or more of the following metals: aluminium, nickel, gold, copper and / or titanium.

4. Separator insert according to one of the preceding claims, characterized in that the metallic coating material comprises or consists of silver.

5. Separator insert according to one of the preceding claims, characterized in that the metallic coating is directly and metallurgically bonded to the drum wall.

6. Separator insert according to one of the preceding claims, characterized in that the surface quality of an uncoated surface of the drum wall is lower than the surface quality of the coated inner surface.

7. Separator insert according to one of the preceding claims, characterized in that several or all of the product-contacting surfaces arranged in the separator insert have the metallic coating.

8. Separator insert according to one of the preceding claims, characterized in that the separator insert is arranged interchangeably on the frame, such that the separator insert forms a pre-assembled, interchangeable unit for insertion into stator units on the frame of the separator.

9. A method for providing a separator insert according to one of the preceding claims, characterized by the following steps: A. Providing the separator insert (1ll) with components made of plastic or a plastic composite material and B. Applying the metallic coating by surface vapor deposition to individual or all components from step A.

10. Method according to claim 9, characterized in that the surface vapor deposition is carried out as a vacuum coating or physical surface coating.

11. Method according to claim 9 or 10, characterized in that the provision in step A is manufactured using additive manufacturing processes.

12. Use of a metallic coating as a diffusion barrier layer, in particular for protection against plastic corrosion and / or as a diffusion barrier layer, on a product-contacting plastic or plastic composite surface of a separator insert (II) of a separator, in particular the drum (3) of a separator according to one of the preceding claims.

13. Use of a metallic coating for surface smoothing on a plastic or plastic composite surface of a separator insert (II) of a separator, in particular the drum (3) of a separator according to one of the preceding claims.

14. Use of a metallic coating as an aseptic and / or antimicrobial coating on a plastic or plastic composite surface of a separator insert (II) of a separator, in particular the drum (3) of a separator according to one of the preceding claims.

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