SEPARATOR

Description

[0001] The invention relates to a separator according to the preamble of claim 1.

[0002] Centrifugal separators for continuous operation have long been known, for example, in a design as nozzle separators from JP 62-117649 A. In addition to nozzle separators, those with solids discharge openings are also known. These are associated with a hydraulically actuated piston valve with which the solids discharge openings can be closed and opened. A separator without solids discharge in a separator design is shown in US 2,017,734. A separator with bolted-together, solid drum upper and lower sections is also shown in US 2,286,354.

[0003] From the generic WO 2014 / 000829 A1, a generic separator for separating a flowable product into different phases or for clarifying a product is also known. The separator comprises a rotatable drum with a drum lower part and a drum upper part, and a clarification means arranged in the drum, wherein one, several, or all of the following elements are made of plastic or a plastic composite material: the drum lower part, the drum upper part, and the clarification means. In this way, it is possible to design part of the drum or preferably even the entire drum—preferably including the inlet and outlet systems or areas—for single use, which is particularly advantageous for processing pharmaceutical products such as fermentation broths or the like.This is interesting and advantageous because, after processing a corresponding product batch, the drum does not need to be cleaned during continuous operation, but the entire drum can be replaced. This separator is therefore particularly advantageous from a hygienic point of view.

[0004] It is therefore desirable - and this is the object of the invention - to further improve the running properties and also the handling of the generic construction.

[0005] The invention solves these problems by the subject matter of claim 1 and the remaining independent claims.

[0006] According to claim 1, a separator for the centrifugal processing of a flowable product is provided, having at least the following features: a rotatable drum which delimits a centrifugal chamber, and wherein the drum is arranged in a housing, wherein a means for clarifying the product to be processed in the centrifugal field (orto optimize the clarification effect) is arranged in the inner drum, wherein the means for clarification is designed as a plate package made of a stack of separating plates, which is preferably made of plastic or a plastic composite material, and characterized in that the drum has an outer support device and an inner drum inserted and arranged in the outer support device, wherein the entire inner drum together with an inlet and outlet system is designed as a replaceable, pre-assembled module and wherein the inner drum has an inner drum lower part and an inner drum upper part, wherein the inner drum lower part and the inner drum upper part are connected to one another in a non-removable manner.

[0007] This significantly improves the running behavior of the rotating system, especially the drum, because the outer support device stabilizes the system. Since this support device is located radially outward relative to the drum wall, which defines the drum's interior, the actual drum, which defines the spinning chamber, is hereinafter referred to as the "inner drum."

[0008] According to one variant, the outer support device is designed as an outer ring that axially surrounds the inner drum in sections. Such a ring, similar to a "bandage," stabilizes the structure on the outer circumference. The at least one stabilizing ring (or the multiple rings) is preferably made of metal, but can also be made of a plastic or a plastic composite material. It is also conceivable to provide a contour, for example, an annular pocket open axially in one direction, on the outer circumference of the inner drum, into which the stabilizing ring is inserted.

[0009] According to a preferred embodiment, it is further advantageous if the outer support device is designed as a circumferentially closed outer ring that axially surrounds the inner drum in sections. However, it is also conceivable for the outer support device to be designed as a grid-like outer ring that surrounds the inner drum over a specific axial section.

[0010] According to another variant, the outer support device is designed as an outer drum which surrounds the inner drum completely or in sections. In this way, the running behavior of the rotating system, in particular of the drum, is significantly improved in a simple manner, since the outer drum stabilizes the system dynamically and mechanically. Both deflections of the rotating system in the radial direction to the axis of rotation D and the tendency for imbalance to form can be significantly reduced. Both the inner drum and the support structure can - but do not have to - be designed with relatively thin walls. In particular, the inner drum, which is preferably replaced after processing a product batch, can be manufactured with very little material in this way.

[0011] Nevertheless, it remains possible to utilize the advantages of the "plastic" or "plastic composite" material, as it is still possible to design part of the drum – the inner drum and preferably its components – especially including the inlet and outlet systems or areas – for single-use. This means that after processing a corresponding product batch, during operation, which is preferably continuous and sanitary during the processing of the product batch, the drum does not need to be cleaned, but the entire drum is replaced. This replacement is particularly simple because the outer drum, which is preferably reused, does not require extensive cleaning, as it preferably does not come into contact with the product being processed at all. Therefore, it does not need to be cleaned and / or disinfected every time the inner drum is changed, or only for a relatively short time.

[0012] Changing the inner drum and its assembly, disassembly and other handling can also be carried out in a simple manner, because since there is a stable outer drum construction into which the inner drum only needs to be inserted, it is possible to provide the drive connection to an electric motor only on the outer drum, so that when changing the inner drum only has to be removed from the outer drum and another inner drum has to be inserted into it again, without the need for many complicated assembly steps such as establishing a drive connection to the drive shaft.

[0013] The outer drum can completely surround the inner drum. However, the rotating system is also well stabilized if the outer drum only axially surrounds the inner drum in sections, preferably over at least 50% of the axial length of the inner drum or more. In the latter case, it is advantageous if the inner drum protrudes axially from the outer drum, which makes it easier to clearly separate and space the inlet and outlet areas of the inner drum from the outer drum.

[0014] It is particularly advantageous if the inner drum and outer drum are made of different materials, as this allows the optimal materials to be selected for both the outer drum and the inner drum. The inner drum is preferably made of a relatively thin-walled plastic or a plastic composite material, so that it can be easily disposed of, and the reusable outer drum is made of metal, particularly steel, so that its running properties can be particularly well optimized.

[0015] Another advantage is that when using a metal outer drum and a plastic inner drum, the weight of the outer drum can significantly exceed that of the inner drum, so that the rotational behavior is essentially determined by the outer drum. For this purpose, the weight of the rotating parts of the metal outer drum is preferably more than twice as great, in particular more than four times as great, as the weight of the rotating plastic parts or the weight of the empty inner drum. The outer drum also makes it possible to design the inner drum with particularly thin walls, as it is stabilized by the outer drum.

[0016] To ensure easy and efficient insertion of the inner drum into the outer drum, it is advantageous for the outer drum to have an outer drum lower section and a detachable outer drum upper section. However, it is primarily advantageous for manufacturing reasons for the inner drum to have an inner drum lower section and an inner drum upper section that can be pre-assembled or is pre-assembled. This is because various elements, such as the clarification agent, an inlet pipe, and the like, must be placed in the inner drum during production. This is simplified by separating the upper and lower sections.

[0017] Mounting the inner drum in the outer drum is particularly easy if the outer drum upper section is designed like a ring that is screwed to the outer drum lower section and is open axially at the top, so that the inner drum upper section protrudes axially from it. The outer drum lower section and the outer drum upper section can also be connected in other ways. One advantageous variant is a connection with screw bolts. A bayonet as a connecting means is also conceivable. Finally, it is advantageous to connect the outer drum upper and the outer drum lower section with a locking ring or to fix them relative to one another. For this purpose, a lower edge of the outer drum upper section is preferably inserted into the outer drum lower section, where it can rest on a collar.Then a ring with an external thread is screwed from above into an internal thread of the outer drum base, which fixes the outer drum upper part to the outer drum base.

[0018] In order to achieve a safe rotation with as little slippage as possible between the inner drum and the outer drum, it is advantageous if the inner drum and the outer drum are connected to each other in a force-locking and / or form-locking manner.

[0019] For hygiene reasons, it is also advantageous if the drum's inlet and outlet systems are located exclusively on the inner drum, so that the outer drum does not come into contact with the product being processed during operation. Preferably, the inlet and outlet systems are formed in a sealed design on the inner drum.

[0020] In a further embodiment, it is advantageous if the inlet system and the outlet system have a cover ring body that is designed as a part that does not rotate with the drum during operation, and if the inlet system has an inlet pipe that is designed as an element that rotates with the drum. For this purpose, the cover ring body is preferably connected in a rotationally fixed manner to an abutment of the separator outside the drum.

[0021] This allows the product to enter the rotating system at the inlet of the feed pipe, simplifying the design of the inner drum. The discharge system is preferably designed without a centripetal pump. The phases to be discharged flow from rotating channels between pipe ends / sections into annular spaces in the non-rotating cover ring body and from there into non-rotating discharge lines and downstream tanks or similar.

[0022] However, according to a less preferred variant, which is more complex in terms of construction, it is also conceivable to implement the drainage system with the aid of one or more plastic grippers which, like centripetal pumps, guide the one or more phases separated in the centrifugal field out of the drum.

[0023] It can also be provided that the drainage areas of the drainage system are designed as ring channels that open axially into annular spaces of the cover ring body.

[0024] According to a further development, at least one or more of the tubular elements of the drum are axially displaceable within the annular body, and a device is provided for releasably securing the tubular element in an axial position within the annular body. This stabilizes the structure easily during transport and prevents it from coming loose. This locking mechanism is only released at the assembly site, allowing these elements to rotate relative to one another. This design is useful for an inner drum, but also for a drum without an inner drum, for example, as described in WO 2014 / 000829 A1.

[0025] It is also advantageous to use the transport lock when removing the drum. To do this, the transport lock is reactivated after / during removal of the inner drum, making it easier to remove and dispose of. Cable ends can be resealed (e.g., with adhesive, clamping, or locking).

[0026] Overall, it is particularly advantageous for handling reasons that the entire inner drum, including the inlet and outlet system, is designed as a replaceable, pre-assembled module. This module preferably consists entirely or at least predominantly (i.e., in particular, more than 70%, in particular more than 80% of the weight of the module) of plastic or a plastic composite material. It is also conceivable to provide limited local reinforcements, e.g., made of metal, plastic, or another suitable material, in the area of ​​the inner drum. The inner drum therefore also forms the independent subject matter of claim 22.

[0027] The actual inner drum is designed as a circumferentially closed drum extending around the drum's axis of rotation, which preferably forms a self-supporting unit. This self-supporting unit is so dimensionally stable that it retains its shape after being placed on the outer drum lower part without the outer drum upper part attached (at rest, i.e., not rotating). In this embodiment, it is therefore not a type of non-dimensionally stable bag or the like. Furthermore, the inner drum is preferably not integrally connected to the outer drum, i.e., it is not a coating of the outer drum or the like.

[0028] The outer drum top section should preferably have a central opening large enough to allow it to be inserted from above over the cover ring body, along with its supply and discharge connections and any attached hoses, which simply need to be connected after installation. This makes installation of the inner drum particularly quick and easy after removing the outer drum top section.

[0029] The means for clarifying a product to be processed from one phase containing more solids per volume fraction than the other phase is preferably and advantageously a separating plate package made of conical separating plates made of plastic, but can also be, for example, a one-piece clarification / separation insert made of plastic as in DE 10 2008 052 630 A1 or another means for clarifying a product from solid particles such as a ribbed body with radial ribs or the like. The separator drum is preferably used to further concentrate a product, i.e., the clarification means separates a phase containing more solids per unit volume, but which is preferably still just flowable, from a phase containing fewer solids. The term "clarification means" is to be interpreted relatively. It also refers to this application, whereby here the clarification means serves to further concentrate the product orto gain a concentrated phase.

[0030] Overall, even with the inner drum concept, some and preferably even all of the product-contacting areas of the rotating system are made of a plastic or a plastic composite material, in particular the inner drum lower section and the inner drum upper section and the disc pack. Furthermore, the inlet system and the outlet system are preferably made entirely or predominantly of plastic or a plastic composite material, which is advantageous for single-use.

[0031] It is advantageous if all or at least the majority of the rotating parts of the inner drum during operation and the parts of its inlet and outlet system that do not rotate during operation—insofar as they come into contact with the product—are made of plastic, and if, apart from any seals that may be required, only a few parts are used, e.g., injection-molded plastic parts. Additionally / alternatively, pipe sections can be designed as metal sleeves, or parts of the inner drum or in / on the inner drum, in particular pipe sections, can be reinforced with one or more metal sleeves.

[0032] These are preferably the inner drum lower section, the inner drum upper section, the distributor, the separation means (preferably the disc insert for separating solids), a separating disc, and the drain. Sealing rings may also be present. This creates a functional plastic centrifuge drum consisting of very few components, making it particularly easy to manufacture and assemble. The separating disc and inner drum upper section could also be formed as a single piece. In this case, the drum upper section would be directly provided with one or more channels through which, like a separating disc or similar, one or more phases can flow from a larger diameter area in the drum to its tip and into a drain from the rotating system.

[0033] It is also particularly advantageous that the inner drum lower and upper sections are permanently connected to each other during initial assembly, preventing any attempts to disassemble and possibly reuse them after inadequate cleaning. Instead, the inner drum is completely disposed of or recycled. Another advantage of this is that sterility is ensured. The design is preferably such that no air from outside can penetrate the inner drum before and after installation.

[0034] With the inner drum concept, as in WO 2014 / 000829 A1, it is also possible to design part of the drum or preferably even the entire drum - preferably including the inlet and outlet systems or areas - for single use. This is particularly interesting and advantageous with regard to the processing of pharmaceutical products such as fermentation broths or the like, since after operation for processing a corresponding product batch in operation, which is preferably continuous during the processing of the product batch, the drum does not need to be cleaned, but the entire drum is replaced. This easily eliminates the hygiene problems associated with cleaning. The parts that come into contact with the product can be disposed of or recycled in their entirety. Disposal is also particularly important for hazardous substances.It is also conceivable, in a product clarification process, to primarily concentrate the product to be processed and, after processing a batch, to melt the inner drum or, for example, dissolve it in an acid or similar solution to recover the heavy substance as a residue from this process. Furthermore, by using preferably thin-walled plastic parts, manufacturing costs can be kept relatively low.

[0035] It is again advantageous and particularly hygienic if the entire drum, in particular its inlet system and its outlet system, is / are designed in a sealed manner.

[0036] The preferred plastic is a recyclable plastic, especially PE (polyethylene), PP (polypropylene), or TK-PEEK (particularly semi-crystalline) polyetheretherketone. Other possible materials (and this is not an exhaustive list) include PC (polycarbonate), MABS (methyl methacrylate acrylonitrile butadiene styrene), ABS (acrylonitrile butadiene styrene), and PSU (polysulfone).

[0037] The plastic parts could be manufactured using the injection molding process and, if necessary, further processed, e.g., provided with holes etc. where necessary.

[0038] Screws and the like can also be made of plastic, but they can also be made of another material, especially if they are not touched by the product during processing.

[0039] Another particularly advantageous invention is specified in the claims, which relate to an advantageous drum for a separator, provided as an inner drum (claim 19), and its advantageous developments. The inner drum of the invention, in particular, runs particularly smoothly and is therefore well suited as an inner drum for an outer drum. Of particular note are the integrated means for clarification in the inner drum, as well as the advantageous form-locking means provided in a further development for surprisingly secure and effective torque transmission between the inner drum and outer drum. A purely clamping movement of the inner drum has proven less than optimal due to effects such as slippage and the like. The inner drum is thus well suited for single-use applications—particularly when pretreated with radiation such as gamma radiation.

[0040] Further advantageous embodiments can be found in the remaining subclaims.

[0041] The invention is described in more detail below using exemplary embodiments with reference to the figures. It shows: Fig. 1 in a) a view of a separator according to the invention with a direct drive and with a sectioned housing and drum, in b) a more detailed and enlarged view of an outer peripheral area of ​​a separator drum, in c) and d) alternative embodiments of the area from a), in e) a more detailed and enlarged view of an inlet and outlet area of ​​the separator drum from Fig. 1a; and in f) an enlarged view of an outer peripheral area of ​​another separator drum. Fig. 2 a section through an inlet area of ​​a separator drum; Fig. 3 in a) a section through another inlet area of ​​a separator drum and in b) and c) sections perpendicular to view a), once in a transport and once in a non-transport position; Fig. 4 a section through an inlet area of ​​a separator drum; and Figs. 5, 6 and 7 sectional views of a partial area of Fig. 1a in alternative designs.

[0042] Fig. 1shows a section through the area of ​​a housing 1 and a drum 2 of a separator according to the invention, with which a liquid product can be separated into two phases in a centrifugal field. The drum 2 has a vertical axis of rotation D. Terms used below, such as "top" or "bottom," refer to the orientation of elements of the separator with respect to this vertical axis of rotation.

[0043] The housing 1 has a lower base 3, a housing shell 4 and an upper cover 5. The base 3 in turn has a passage 6 through which a rotatable drive spindle 7 passes. Preferably, a drive motor 8 is arranged directly below the base 3. This drive motor 8 serves to drive the drive spindle 7. Alternative designs are conceivable, for example one in which the drive spindle 7 is driven by a drive belt or the like, in which case the drive motor is arranged at a different location. However, a direct drive is preferred, in particular in the manner of Fig. 1, in which the drive shaft of the motor is arranged directly in the vertical extension of the drive spindle 7. Preferably, a separate bearing for the spindle construction is omitted, which makes the construction simple and relatively inexpensive to implement. This construction is simple and robust and very well suited for the lightweight drum construction. The function of supporting the drum is simply performed by the electric motor or its rotor bearing.

[0044] The drum 2 is in turn mounted on the vertically upper end of the drive spindle 7 in a manner that is non-rotatable relative to the drive spindle 7, so that it can be rotated by the drive spindle 7 and the drive motor 8.

[0045] The drive spindle 7 could be rotatably mounted in the housing 1, here in the base 3, with one or more bearings. However, such a bearing can also be omitted. Instead, a gap 9 is formed between the outer circumference of the drive spindle and the inner circumference of the passage 6 of the base 3. In this way, a bearing of a drive shaft 10 in the motor housing of the drive motor 8, to which the drive spindle 7 is fixed or on which it is formed in some other way, can also be used in a simple manner to support the entire rotating system consisting of the drum 2 and the drive spindle 7. It is therefore also preferred that the drive spindle 7 is directly coupled to the output shaft of the motor and that the drive spindle 7 does not have an additional pivot bearing - for example, no neck bearing or no foot bearing - on its outer circumference. Preferably, no spring system for resilient support is provided in the area of ​​the drive spindle either.A seal 72 ensures sealing of the gap 9. The seal 72 can, for example, be a mechanical seal or another suitable seal in the annular gap 9 between the parts 3, 7 rotating relative to one another.

[0046] The structure of drum 2 will now be explained in more detail, which differs considerably from the structure of known designs.

[0047] The drum 2 has an outer drum 11, which can also be designed as an outer drum section, and an inner drum 12.

[0048] Preferably, the outer drum section or outer drum 11 and inner drum 12 are made of different materials. The outer drum 11 is preferably made of metal, in particular steel, and the inner drum 12 is preferably made entirely or at least partially, in particular predominantly, of a plastic or plastic composite material.

[0049] The outer drum 11 serves as a type of holder into which the inner drum 12 is inserted. This holder completely surrounds or encloses the inner drum 12 in the vertical or axial direction, at least in sections. The outer drum 11 and the inner drum 12 are preferably connected to one another in a rotationally fixed manner. This can be achieved in particular by a positive and / or non-positive connection between the outer drum 11 and the inner drum 12.

[0050] The outer drum 11 has an outer drum lower part 13, which can be designed essentially like the drum lower part of known separators without an inner drum, or here is. The outer drum lower part 13 is mounted on the drive spindle 7 in a rotationally fixed manner and preferably has a single-conical or, here, preferably double-conical inner shape, which leads to good rotation and separation behavior on the separator drum. The outer drum 11 further preferably has an outer drum upper part 14. The outer drum lower part 13 and the outer drum upper part 14 preferably have corresponding threads 71, in the area of ​​which they are directly screwed together. Here, the thread of the outer drum lower part section is designed as an internal thread of the drum lower part, and the thread of the outer drum upper part 14 is designed as a corresponding external thread.

[0051] The outer drum upper part 14 is also conical. It is also designed as a ring that is connected at the bottom in a rotationally fixed manner to the outer drum lower part 13 and is open at the top, so that the inner drum 12 protrudes vertically or axially upwards from the outer drum, here from the outer drum upper part 14. Preferably, the outer drum upper part 14 extends only into the conical section of the inner drum upper part 17, so that the latter still protrudes vertically upwards from the outer drum upper part 14 with part of its conical region (preferably more than 20% of the vertical length of this region). It has been shown that this already leads to very good rotational behavior. The outer drum upper part can thus be reduced to a conical ring.

[0052] Since the outer drum lower part 13 and the outer drum upper part 14 are preferably made of metal, in particular steel, and preferably at least the drum lower part is designed like that of a separator drum without an inner drum 12, they can largely offer the smooth running, stability, and safety of a known modern separator drum made of metal. Since the outer drum 11 surrounds the inner drum 12 partially or entirely on the outside, the outer drum stabilizes the inner drum. In particular, the outer drum 11 advantageously contributes to optimizing the running properties of the entire drum 2 during operation at high speeds. Furthermore, the wall thickness of the inner drum 12 can also be selected to be much thinner than that of a separator drum consisting solely of plastic without an outer drum 11, as proposed in WO 2014 / 000829 A1.

[0053] The inner drum 12, on the other hand, delimits the actual separation or centrifugal chamber 15 for the centrifugal processing of a flowable product.

[0054] The inner drum 12 is designed in such a way that it preferably lies directly against the inner circumference of the outer drum in a largely form-fitting manner.

[0055] The inner drum 11 has an inner drum lower part 16 and an inner drum upper part 17. Preferably, the inner drum lower part 16 and the inner drum upper part 17 are each conical, so that a double-conical body is formed. The parts 16 and 17 are made of plastic or a plastic composite material and are connected to each other in a liquid-tight manner, in particular in the upper (inner drum lower part 16) and lower (inner drum upper part 17) flange areas 18, 19 (see Fig. 1b ).

[0056] Preferably, a material connection is provided between the inner drum lower part 16 and the inner drum upper part 17 and possibly further elements of the inner drum 12, which in the sense of this document can be achieved, for example, by fusing but also by gluing.

[0057] Other types of connection are also conceivable, such as a bayonet lock between the elements to be connected, the inner drum lower part 16 and the inner drum upper part 17. Fig. 1c and 1d illustrate different connection variants between the elements to be connected, the inner drum lower part 16 and the inner drum upper part 17, in which these are connected to one another via a snap-in connection.

[0058] For this purpose, either the inner drum upper part 17 ( Fig. 1c ) or on the inner drum base 16 ( Fig. 1d) one or more first and second locking means 60, 63 are provided, which are intended to interact with a corresponding locking edge or contour on the other inner drum part. The first locking means 60 can be designed as one or more webs 61 formed axially on the outer circumference of the inner drum upper part 17, extending axially in the direction of the inner drum lower part and having a radially inwardly projecting locking contour 62 which engages under the inner drum lower part 16 at the outer circumferential edge - which thus forms the counter-locking means. Alternatively, the webs 61 can be formed with a radially inwardly projecting locking contour 62 on the inner drum lower part 16 and engage over the inner drum upper part 17 at the outer circumferential edge - which thus forms the counter-locking means 63.

[0059] Other connection variants between the inner drum lower part 16 and the inner drum upper part 17 can also be advantageously implemented, such as screw connections with plastic screws and nuts or the like (not shown here). It is also a practical connection if the inner drum lower part and the inner drum upper part are clamped together at their outer circumference with one or more clamps (not shown here). These types of connections between the inner drum parts 16, 17 are easy to handle, cost-effective to implement, and yet highly functionally reliable.

[0060] Between flange areas 18, 19 between the inner drum lower part 16 and the inner drum upper part 17, at least one preferably circumferential sealing ring 64 can be arranged axially in order to ensure the tightness of the (plastic) inner drum ( Fig. 1c and 1f ).

[0061] This sealing ring 64 can be a separately inserted sealing ring or can be designed as a sealing ring strip that is molded onto one or both of the flange areas.

[0062] After Fig. 1f The inner drum lower part 16 and the inner drum upper part 17 each have, in the area of ​​their largest outer circumference, upwardly (inner drum lower part 16) and downwardly (inner drum upper part 17) open and U-shaped in cross-section grooves 82, 83, which in the assembled state of the inner drum 12 engage with each other and form an annular space 84 with a circumferentially closed cross-section. The sealing ring 64 is arranged in the annular space 84. During rotation, it lies radially outwards and expands, so that the annular space or the interior of the inner drum 12 is well sealed. In addition, a locking mechanism such as a latch can be formed between the inner drum lower part 16 and the inner drum upper part 17. The outer drum lower part 13 extends in Fig. 1fadvantageously vertically upwards so far that it stabilizes the inner drum radially outward in the area of ​​the grooves 82, 83.

[0063] In Fig. 1f Furthermore, the inner drum upper part 17 is screwed to the inner drum lower part with a stepped locking ring 85, with corresponding threads 86 being formed between the locking ring 85 and the inner drum lower part 17, and with the locking ring 85 pressing the inner drum upper part 17 against the inner drum lower part 16. This also supports a very good sealing effect.

[0064] A lower section 20 of the inner drum lower part 16 is connected axially upwards as a separate part or as a distributor connected in one piece with the inner drum lower part and coaxially surrounding the rotation axis D, in particular distributor attachment 21 (see again Fig. 1a), which forms a complete distributor for introducing the centrifugal material into the inner drum interior or centrifugal chamber 15 and for accelerating the centrifugal material in the circumferential direction during rotation of the drum 2.

[0065] In the upper area of ​​the distributor attachment 21, for example, a blind hole-like bore is formed, into which an inlet pipe 23 opens. The inlet pipe 23 can also be molded directly onto the distributor attachment or otherwise formed integrally with it. The inlet pipe 23 and the distributor attachment 21 form an inlet system that is preferably advantageously sealed against the environment. The inlet pipe 23 preferably protrudes axially upward from the inner drum upper part 17 and rotates with the drum 2 during operation.

[0066] The distributor attachment 21 opens at the lower end into one or more distribution channels 24, which are formed obliquely to the axis of rotation and here also open obliquely into the actual centrifugal chamber 15.

[0067] In the centrifuge chamber 15, separation means or clarification means are arranged, i.e., a single-piece or preferably multi-piece plate stack 25 formed as a stack of axially spaced separation plates 26, which have a conical basic shape and are preferably mounted in a rotationally secure manner on the distributor attachment 21. The separation means for clarification could also be formed in a different shape, such as ribbed bodies with radial or curved ribs. The separation plates 26 have the same or different radii.

[0068] The distributor attachment or distributor 21 can also be formed integrally with the clarification means if it is designed as a plastic clarification insert with clarification chambers as described in DE 10 2008 052 630 A1. A product introduced into the inner drum interior or centrifuge chamber 15 is separated in the drum 2 into various, preferably two, product phases of different densities.

[0069] A drainage system with two or more drainage areas is used to drain the various product phases from drum 2.

[0070] Thus, a lighter liquid phase flows radially inwards and is there (see Fig. 1a and e ) is guided axially upwards in a channel 27 on the outside of the distributor attachment 21 into an annular channel 28 which is formed between the outer circumference of the inlet pipe 23 and a pipe section 29 of larger diameter which also projects from above into the inner drum upper part 17.

[0071] At the bottom of this pipe section 29, a conical plate is attached, in particular glued or molded on, which is arranged like an upper separating plate 30 above the separating plate assembly, being spaced from the drum upper part so that a gap is formed between the drum upper part and the separating plate. At the lower end, a flange-like peripheral edge 31 (see Fig. 1b ) is placed between the flange areas 18 and 19 of the inner drum lower part 16 and the inner drum upper part 17 and is preferably firmly glued to them, which stabilizes the arrangement of the separating plate 30 and also gives the entire construction additional strength.

[0072] A heavier liquid phase (or a solid phase that can still be drained off, in particular one that is still somewhat free-flowing) is guided from the region of the largest inner circumference of the drum interior through one or more bores 32 in the radially outer region of the separating plate into the gap 33 acting as a channel between the inner drum upper part 17 and the separating plate 30, preferably into a second annular channel 34 - or into one or more channels that are preferably spaced apart by ribs - between the pipe section 29 surrounding the inlet pipe and an axial pipe extension 45 of the inner drum upper part 17.

[0073] The heavier and lighter liquid phases flow upwards from the annular channels 28, 34 into axially stacked annular spaces 35, 36 in a cover ring body 37, which is non-rotatably mounted (in a manner to be explained in more detail) on the housing 1. It is advantageous that this eliminates the need for nozzles or the like leading radially out of the drum for solids removal, so that there is no contact between the interior of the drum and the drum environment in the container.

[0074] The cover ring body 37 is preferably designed in a stepped manner and has in its vertically uppermost area a connecting piece 38 as a connection option for a supply line 75 (which, however, is Fig. 2can be seen and will be explained in more detail below). Starting from the connecting piece 38, the cover ring body 37 widens gradually. The internally hollow connecting piece 38 opens into an axially uppermost annular space 39 on the inner circumference of the cover ring body 37, into which the upper end of the inlet pipe 23 extends axially from below. This pipe rotates with the drum during operation of the centrifuge and although it opens into the annular space 39, it is spaced from the cover ring body 37 at every point in the annular space 39. In this way, the incoming centrifugal material to be processed is transferred into the rotating system in a simple manner. At the bottom, each of the annular spaces 39, 35, 36 is preferably delimited by a sealing arrangement 40, 41, 42 on one or more (here two) sealing rings which are arranged between the outer circumference of the inlet pipe 23 and the inner wall of the annular space.As sealing arrangements 40, 41, 42, preferably two sealing rings spaced axially apart from one another are provided, in particular in the manner of mechanical seals.

[0075] Below the uppermost sealing arrangement 40, the cover ring body 37 widens further at a next step. Between the inlet pipe 23 and the inner circumference of the cover ring body 37, below the uppermost sealing arrangement 40 and above the middle sealing arrangement 41, the middle annular space 36 is formed between the outer circumference of the inlet pipe 23 and the inner circumference of the cover ring body 37. This serves to drain the light liquid phase. For this purpose, a further connecting piece 43 can be formed on the cover ring body 37, which preferably extends radially or obliquely away from the rest of the cover ring body 37. The pipe end, which adjoins the separating plate 30, opens into this annular space 36 from below. The middle sealing arrangement 41 is arranged between the outer circumference of the pipe section 29 and the inner circumference of the cover ring body 37.

[0076] Below the middle sealing arrangement 41, the cover ring body 37 widens further at a subsequent step. The annular space 35 is formed between the outer circumference of the pipe section 29 and the inner circumference of the cover ring body 37, below the middle sealing arrangement 41 and above the lower sealing arrangement 42. This lower annular space 35 serves to drain a fluid phase, which is heavier than the lighter one, from the rotating system.

[0077] For this purpose, a further connecting piece 44 can be formed on the cover ring body 37, which preferably extends (in this case obliquely) radially away from the remaining cover ring body 37. The lower sealing arrangement 42 is arranged between the outer circumference of the tube extension 45 of the inner drum upper part 17 and the inner circumference of the cover ring body 37.

[0078] Leakage chambers 80 can be formed on the sealing arrangements 40, 41, 42, from which leakage fluid can flow out of the rotating system through connection pieces 81, wherein lines and / or leakage containers are in turn connected to the connection pieces 81.

[0079] Below the sealing arrangement 42, the annular body 37 widens further. It is secured by means of fastening means on its lower circumferential edge to an upper opening in the housing, through which the annular body, the tube extension 45, and the elements extending through the tube extension pass. This securing can be achieved, for example, by means of circumferentially distributed screws 22 that are screwed to the housing 1 (preferably to the cover 5). The annular body 37 can have corresponding threaded screw receptacles 73 for this purpose.

[0080] In order to connect the inner drum and the outer drum 12, 11 to each other in a simple manner in a rotationally fixed but detachable manner when stationary, it can be provided that the inner drum 12 is connected to the outer drum 11 in a form-fitting and / or force-fitting manner.

[0081] A force-locking connection can be realized in a simple manner by the flange areas 18 and 19 as well as the outer edge 31 of the separating plate 30 extending into the screwing area between the outer drum lower part and the outer drum upper part, where they each rest on steps of these parts and are screwed between them when screwing the drum upper part into the drum lower part ( Fig. 1b ).

[0082] In addition, form-locking means such as ribs 87 (and / or grooves) on the outer circumference of the inner drum and corresponding grooves 88 (and / or ribs) on the inner circumference of the outer drum 11 can be provided, which engage with each other and thus connect the two elements, inner drum 12 and outer drum 11, in a rotationally fixed manner ( Fig. 1a ).

[0083] It has proven particularly advantageous if one or more of the ribs 87 are formed on the outside (on the outer surface or the outer casing of the outer drum), preferably distributed around the circumference of the inner drum lower part 16, and correspondingly one or more of the grooves 88 are formed on the outside (on the inner surface facing the inner drum), distributed around the circumference of the outer drum lower part 13. The outer drum lower part 13 is advantageously designed to be double-conical and has an inner conical region 13a and an oppositely oriented outer conical region 13b. The inner drum lower part 16 has a corresponding double-conical shape with an inner conical region 16a and an outer conical region 16b. The form-locking means, in particular ribs 87, is / are preferably formed orprotrude therefrom, and the corresponding form-locking means, in particular grooves / recesses 88, is / are formed correspondingly on the inner conical region 13a of the inner drum upper part 13 on its inner surface. It is precisely the arrangement in / this region close to the drive spindle 7 that enables very good torque transmission from the outer drum to the inner drum, guaranteeing very smooth running. However, torque transmission in other areas on the outside of the inner and outer drums is also conceivable.

[0084] During operation, the inner drum 12 will expand radially to fit against the inner circumference of the outer drum 11, which improves the torque transmission and rotational drive of the inner drum 12 by the driven outer drum 11. Alternatively, it would also be conceivable to detachably connect the parts of the outer drum to one another in another way, such as with screw bolts or the like, or by means of a bayonet.

[0085] In this way, some or preferably even all of the product-contacting areas of the rotating system are made of plastic or plastic composite material, in particular the inner drum lower part 16 and the inner drum upper part 17. Furthermore, the separating plates 26 are preferably made of plastic, as are all or almost all of the product-contacting areas of the inlet system and the outlet system, even if they do not rotate during operation. In this way, the inner drum 12 can be disposed of after a sufficiently large product batch has been processed. The preferably metallic outer drum 11, on the other hand, is reused. Since it cannot come into contact with product during operation, cleaning it is very easy or less important. The outer drum 11 allows the inner drum 12 to be designed with very thin walls. With complete disposal, very little plastic waste is generated.

[0086] Fig. 1shows a design as a two-phase separation machine (separation of a product into the phases: "liquid / liquid"). Three-phase machines (for separation into three phases) are also feasible (not shown here). The product is preferably, but not necessarily, a fermentation broth to be concentrated. Thus, the entire inner drum, including the inlet and outlet system, is preferably designed as a replaceable, pre-assembled module made of plastic or a plastic composite material.

[0087] The outer drum section 11 essentially serves as a holder for the inner drum 12, which in particular improves the running properties of the inner drum 12.

[0088] The design of the outer drum top as a ring is optimized in testing. This allows us to determine the conical area to which the ring-like outer drum cover or outer drum top must enclose the inner drum top.

[0089] The structure of the housing 1 will be examined in more detail below. The housing 1 comprises the base 3, a preferably cylindrical housing shell 4, and the cover 5. Only in the area of ​​the cover ring body 37 does the housing come into contact with the plastic area, which can be disposed of after operation.

[0090] The base 3 is designed here as a separate base plate 46. Preferably—but not necessarily—the base plate 46 is round. The housing shell 4 is arranged on the base. Here, an edge region of the base serves as a flange-like support surface 47 for a lower flange section 48 of the housing shell 4, which in this preferred embodiment is cylindrical. The housing shell 4 further has an upper flange section 49, to which the cover 5 is screwed.

[0091] The base plate 36 can be used to support an abutment (not shown here), such as a foundation or a machine frame. For this purpose, holes 74 are also formed in the flange section 48, through which the flange section can be secured to the abutment (for example, with screws (not shown here).

[0092] It is advantageous that the housing 1 has a drain opening 59, preferably in its base 3, through which any liquid that may occur in the housing, for example, due to an unforeseen leak or that would otherwise collect there, can drain away. A drain line, such as a drain hose, can be arranged at a connection to the opening 59 to drain this liquid into a container.

[0093] A particularly compact design is achieved in that - as already mentioned at the beginning - the drive motor is preferably an electric motor, which is arranged directly in the axial extension of the drive spindle 7, preferably on the side facing away from the drum. The drive spindle 7 is preferably connected axially directly to the output shaft 10 with a bolt. It is further connected in a rotationally fixed manner in the circumferential direction to the output shaft of the electric motor by a torque transmission means, preferably a key (not shown here). The torque transmission means can also be designed in a different form - for example, as a torque transmission contour (not shown here in each case). A terminal box 75 is arranged on the motor 8.

[0094] The rotatable drum 2 can be connected to the drive spindle structure with a press fit (e.g., in a conical section) or by means of another torque transmission means (not shown here). The motor 8 is further attached to the bottom of the housing 1 with a flange section 50 on its side facing the spindle 7, for example, by screwing it in with threaded bolts. A terminal box 51 is also arranged on the motor 8.

[0095] Advantageous options for securing the rotating plastic system during transport will be described in more detail. As explained above, it is possible to replace the rotating plastic system from time to time. For this purpose, according to a variant, the invention also provides a device for at least axially securing the cover ring body 37 to an element of the rotating system of the separator of the inner drum, at least in the transport state, i.e., when not mounted in the outer drum and in the housing 1.

[0096] Since the annular body, as a non-rotating part during operation, is connected to the rotating parts with which it forms annular chambers only via the sealing arrangements 40, 41, 42, without a means of at least axial transport securing, there would be a risk that the cover ring body 37 could become axially loose. However, this does not exist during operation, since both the inner drum 12 is supported on the motor via the outer drum lower section and, via the outer drum lower section, on the housing 1, and the cover ring body 37 is supported directly on the housing 1, and are thus sufficiently axially fixed relative to one another.

[0097] In Fig. 2an upper section of the cover ring body 37 with the connecting piece 38 as a connection option for a hose-like inlet line 75 is shown, as well as an upper section of the inlet pipe and the upper sealing arrangement 40. The hose-like inlet line 75 (and similarly hose-like outlet lines on the other connecting pieces 43, 44) is / are preferably pre-assembled and adhesively attached to these. The hoses can be glued at the ends facing away from the connecting pieces. Before commissioning, the glued ends are cut off and welded to a piece of hose, which comes from the fermenter, for example. Other variants for connecting the hoses and pieces and for closing any open line ends are also conceivable. For example, coupling elements that are designed to lock into place, or the ends can be closed with cable ties or similar elements.

[0098] The Fig. 2 to 4also show the inlet pipe 23 in a state in which it is axially further inserted (here upwards toward the upper connecting piece 38) into the body 37 (dashed line) and in a state in which it is moved slightly further axially downwards (solid line). The dashed state or the further inserted state of the inlet pipe 23 indicates the transport state, and the non-dashed line indicates the installation state in the outer drum 11 for operation.

[0099] In Fig. 2 to 4 Variants of the device for at least axially securing the cover ring body to an element of the rotating system of the separator of the inner drum are shown in any case in the transport state, ie in the state not mounted in the outer drum 11 and in the housing 1.

[0100] The axial transport lock is based on a force and / or form fit.

[0101] After Fig.2A combined force and form fit is achieved. Here, a projection 53, for example a pin, arranged on a leaf spring 52 engages in an annular groove 54 on the outer circumference of the inlet pipe 23 when it is further inserted into the cover ring body 37. The force of the spring is selected such that a good transport lock is achieved, but that it is still possible to release the transport lock after transport during assembly by a targeted axial downward movement of the inlet pipe.

[0102] After Fig. 3Such a positive fit in an annular groove 54 of the inlet pipe 23 is achieved by a radially inwardly projecting web 55 on the cover ring body 37 engaging internally in the annular groove 54 of the inlet pipe 23. A taper / bevel 56 at the free upper end of the inlet pipe 23 allows it to be inserted into the transport securing position shown in dashed lines, particularly before disposal of the rotating system or before initial transport.

[0103] To release, the cover ring body 37 must be rotated so that the web 55 is aligned with a radial groove 57 above the annular groove 54. In this position, the discharge pipe can be pulled into its operating position, not shown in dashed lines (see Fig. 3b, c ).

[0104] After Fig. 4A releasable force connection is achieved by placing a type of clamping ring 58 (similar to a tensionable hose clamp) around the outside of the cover ring body 37 and tightening it so that it presses the cover ring body 37 force-fittingly onto the outer circumference of the further inserted supply pipe 23.

[0105] The Fig. 5 and 6 illustrate that local reinforcement elements can also be provided within the plastic drum, in particular the inner drum. Here, these reinforcement elements are designed as sleeves 76, 77, 78. These sleeves are located radially between each of the sealing arrangements 40, 41, 42 and the associated inner pipe / pipe section / pipe socket 23, 29, 45 and reinforce them. Alternatively, one or more of the sleeves can also themselves form a section of a pipe / pipe section / pipe socket 23, 29, 45. Such a configuration is shown in Fig. 7Here, a sleeve 23a forms an axial end of the inlet pipe 23. The sealing arrangement 40 is arranged radially outside the sleeve 23a.

[0106] The sleeves 23a, 76, 77, 78 can be designed to be insulating or heat-conducting, depending on the requirements. They are preferably also made of plastic (preferably a high-temperature-resistant and preferably high-strength plastic). However, it is also conceivable and preferred to manufacture them in other ways, such as from other materials, including plastic composites or other composite materials. Reinforcing elements made of glass, metal, or plastic-metal compounds (e.g., plastic with metal mesh for heat dissipation) are conceivable. These are separated during recycling or disposal if necessary.

[0107] It is particularly advantageous that, due to the choice of material, the sleeves 23a, 76, 77, 78 heat up less than the rest of the pipe / pipe section / pipe extension 23, 29, 45. This is particularly true if the sleeve 23a, 76, 77, 78 is made of metal. It is particularly advantageous if the sleeve essentially forms a pipe section of the pipe / pipe section / pipe extension 23, 29, 45.

[0108] If the sleeve - e.g., 23a - itself forms a section, in particular an end of a pipe, it is expedient to connect it firmly, preferably inseparably, to the remaining pipe / pipe section / pipe extension 23, 29, 45. In the latter case, it is advisable to glue the sleeve to the remaining pipe / pipe section / pipe extension 23, 29, 45 or to place it in the corresponding mold during injection molding of the plastic pipe, so that an intimate connection is created, in particular between metal and plastic. The sleeve 23a, 76, 77, 78 and the pipe / pipe section / pipe extension 23, 29, 45 can also overlap or interlock in sections ( Fig. 7 ).

[0109] If the sleeve is made of metal, the sleeve has a relatively high heat absorption capacity, so that it does not overheat, especially when the drum is accelerating to operating speed. This, in turn, protects temperature-sensitive components, especially the mechanical seals located in its area, which are preferably adjacent to it.

[0110] After Fig. 6 one or more of the sleeves 76, 77, 78 - here on the inner peripheral edge - have one or more grooves, in particular annular grooves 79, or one or more chambers, which contributes to reducing heat conduction by forming air chambers and therefore protects the adjacent elements, in particular seals. Reference symbol Housing 1 drum 2 Floor 3 Housing shell 4 cover 5 Implementation 6 drive spindle 7 drive motor 8 gap 9 drive shaft 10 Outer drum 11 inner drum 12 Outer drum base 13 Conical areas 13a, b Outer drum upper part 14 Spinning room 15 Inner drum base 16 Conical areas 16a, b Inner drum top 17 Flange areas 18, 19 Section 20 Distribution approach 21 screws 22 Inlet pipe 23 Distribution channels 24 Plate package 25 Separating plate 26 channel 27 Ring canal 28 Pipe section 29 Cutting plate 30 peripheral edge 31 Drilling 32 gap 33 Ring canal 34 Annular spaces 35, 36 Cover ring body 37 Connection piece 38 Annular space 39 Sealing arrangement 40, 41, 42 connecting piece 43 connecting piece 44 Pipe socket 45 base plate 46 Support surface 47 Flange section 48 Drilling 49 Flange section 50 terminal box 51 leaf spring 52 projection 53 Ring groove 54 web 55 taper / bevel 56 radial groove 57 clamping ring 58 Drain opening 59 Resting aid 60 Footbridges 61 locking contour 62 Resting aid 63 sealing ring 64 thread 71 seal 72 Screw holders 73 Drilling 74 Inlet line 75 Pods 76, 77, 78 Ring grooves 79 Leakage chambers 80 Leakage nozzle 81 Gutters 82, 83 Annular space 84 Locking ring 85 thread 86 ribs 87 Grooves 88 vertical axis of rotation D

Claims

1. Separator for centrifugal processing of a flowable product, having at least the following features: a. a rotatable drum (2) which delimits a centrifugal chamber (15), the drum (2) is arranged in a housing (1), b. a means for the clarification of the product to be processed in the centrifugal field is arranged in the inner drum (12), c. the means for clarification is designed as a disk stack (25) consisting of a stack of separating disks (26), which is preferably made of plastic or a plastic composite material, and characterized in that d. the drum (2) has an outer support device and an inner drum (12) inserted and arranged in the outer support device, e. the entire inner drum (12), in addition to an inflow and outflow system, is designed as an exchangeable, preassembled module, f. the inner drum (12) has a lower inner drum part (16) and an upper inner drum part (17), wherein the lower inner drum part (16) and the upper inner drum part (17) are connected to one another in a non-removable manner.

2. Separator according to claim 1, characterized in that the outer support device is designed as a circumferentially closed outer ring which surrounds the inner drum (12) axially in sections.

3. Separator according to claim 1 or 2, characterized in that the outer support device is designed as an outer drum (11) in which the inner drum (12) is arranged, and in that the outer drum (11) is circumferentially closed where it surrounds the inner drum (12), and completely surrounds the inner drum (12) in the circumferential direction and / or in that the outer drum (11) serves as a holder into which the inner drum (12) is inserted and in that the outer drum (11) axially surrounds the inner drum (12) only in sections or axially surrounds it completely.

4. Separator according to one of the preceding claims, characterized in that the inner drum and the outer drum (12, 11) are composed of different materials, wherein the inner drum (12) is composed of plastic or a composite plastic material and / or the outer drum (11) is composed of metal, in particular of steel.

5. Separator according to one of the preceding claims, characterized in that the outer drum (11) has an outer drum lower part (13) and an outer drum upper part (14).

6. Separator according to one of the preceding claims, characterized in that the inner drum lower part (16) and the inner drum upper part (17) are connected to one another by a material bond, in particular are bonded or welded, and / or in that the inner drum lower part (16) and the inner drum upper part (17) are mechanically connected to one another.

7. Separator according to one of the preceding claims, characterized in that at least one seal, in particular an encircling sealing ring (64), is arranged or formed between the inner drum lower part (16) and the inner drum upper part (17).

8. Separator according to one of the preceding claims, characterized in that one or both of the following parts is or are of conical design: the outer and inner drum upper part (14, 17) and the outer and inner drum lower part (13, 16).

9. Separator according to one of the preceding claims, characterized in that the inner drum (12) and the outer drum (11) are non-rotatably connected to one another in a force-fitting and / or form-fitting manner.

10. Separator according to one of the preceding claims, characterized in that the inner drum (12) and the outer drum (11) are connected in a rotationally fixed manner to one another by at least one or more corresponding form-fitting means, preferably in such a way that the inner drum (12) has at least one or more ribs (87) as form-fitting means, which engages in one or more corresponding groove(s) (88) on the outer drum lower part (13), wherein further preferably the one or more rib(s) (87) is / are formed on the inner conical region (16a) of the inner drum lower part (16) on the outer surface thereof, and in that the one or more grooves (88) is / are formed correspondingly on the inner conical region (13a) of the inner drum upper part (13) on the inner surface thereof.

11. Separator according to one of the preceding claims, characterized in that the outer drum (11) is driven by a drive motor (8) and / or in that the outer drum lower part (13) is connected to a drive spindle (7) in a rotationally fixed manner.

12. Separator according to one of the preceding claims, characterized in that an inflow system and an outflow system of the drum are formed exclusively on the inner drum (12).

13. Separator according to one of the preceding claims, characterized in that no solids discharge openings, which lead radially out of the inner drum (12) into the space surrounding the inner drum, are formed in the inner drum wall.

14. Separator according to one of the preceding claims, characterized in that the inflow system and the outflow system are formed, in a sealed type of construction, on the inner drum (12).

15. Separator according to one of the preceding claims, characterized in that the inflow system and the outflow system have a covering ring body (37) which does not rotate with the drum during operation and / or in that the inflow system has an inflow pipe (23) which is formed as an element (2) which rotates with the drum.

16. Separator according to claim 15, characterized in that the inflow pipe (23) projects into the covering ring body (37) and in that one or more further pipe elements, which rotate with the drum (2) during operation, project into the ring body (37), and in that one or more seal arrangements (40, 41, 42) with in each case one or more sealing rings are preferably arranged between the covering ring body (37) and rotating pipe elements or ends (23, 29, 45) of the drum.

17. Separator according to one of the preceding claims, characterized in that all regions of the drum (2) which come into contact with product during operation are composed of plastic or a plastic composite material.

18. Separator according to one of the preceding claims, characterized in that at least one outflow duct for a heavy product phase is integrated into the inner drum upper part (17).

19. Drum which can be used as an inner drum for a separator according to one of the preceding claims, characterized in that a means for clarification is arranged or formed in the inner drum (12), in that an inflow and outflow system is formed on the inner drum and in that the inner drum (12) can be inserted into an outer drum (11) and in that the entire inner drum (12), in addition to its inflow and outflow system, is configured as an exchangeable preassembled module and in that the module consists entirely or at least predominantly of plastic or a plastic composite material.

20. Use of an inner drum (12) consisting entirely or predominantly of plastic according to claim 19 of a separator having a metallic outer drum as a disposable drum for one-time processing, in particular concentrating, of a product batch.