FILTER FOR FILTING LIQUID METAL

Abstract

The present invention relates to a filter for filtering liquid metals, comprising a filter housing with a filter base and a filter cover, and a filter element arranged within the filter housing. The filter housing has at least one inlet and at least one outlet. The filter base and the filter cover have connecting structures designed such that, when the filter cover is rotated relative to the filter base, the height of the filter housing increases or decreases along the longitudinal axis of the filter element.

Description

[0001] The present invention relates to a filter for filtering liquid metals, comprising a filter housing comprising a filter base body and a filter cover, and a filter element arranged within the filter housing. The filter housing has at least one inlet and at least one outlet. The filter base body and the filter cover have connecting structures designed such that upon rotation of the filter cover relative to the filter base body, the height of the filter housing increases or decreases along the longitudinal axis of the filter element. State of the art

[0002] Filters for filtering liquid metals are already known. A simple form of such filters is described in DE 3902151 A1. The filter housing is designed as a cast-in unit. The filter element is a disc inserted into the filter housing. The filter element creates two separate spaces: one for unfiltered liquid metal, the inlet and the space behind it up to the filter element, and one for filtered liquid metal, downstream of the filter element and the space behind it up to the outlet.

[0003] DE 4229417 C2 discloses a different geometry of a filter housing for filtering liquid metals, comprising a filter housing made of refractory material, with at least one inlet and one outlet, wherein at least one filter element is arranged between the inlet and outlet, and the filter housing has an annular channel on the inlet side and an inner collecting chamber enclosed by the annular channel on the outlet side, with the filter element arranged between the annular channel and the collecting chamber. The filter housing consists of a refractory material, in the interior of which several filter discs are inserted to form a circle or an oval. These can also be arranged in a different geometry (for example, n-gon), and a further structure made of the same or similar refractory material as the filter and / or housing can be used, which structure in particular supports and / or guides the filter elements.

[0004] A known problem with prior art filters is that their filtration performance is often relatively low. Among other things, the filter elements can become blocked quickly, which is disadvantageous and limits the overall casting performance of the filters. The prior art attempts to increase casting performance by using a type of "filter bank" as filter elements. This involves several flat filter discs being placed side by side as filter elements, primarily in recesses located in the mold parting plane. However, this requires considerable effort in manufacturing these filters, increases the risk of filter breakage, and leads to uneven throughput of the respective liquid metal.

[0005] To avoid the high costs involved in producing and assembling multiple flat filter discs as a filter element, one-piece, tubular filter elements are known from the state of the art. However, the problem with these tubular filters is that, due to their production process, these ceramic tubular filter elements are often subject to large manufacturing tolerances, which negatively impacts the precise and secure positioning of these filter elements, particularly in filter housings. If both tolerance ranges are not aligned correctly, normal, safe use is no longer possible, as the conventionally manufactured filter housings can then no longer be closed, or a significant gap develops between the two housing parts, requiring parts of the system to be scrapped or extensively reworked.

[0006] The invention is therefore based on the aim of providing a filter which enables a higher filtration performance, an improved adaptability of the filter housing to the filter element, especially with regard to the manufacturing tolerances of the filter element, and an easy installation in the casting system.

[0007] These and other advantages are achieved with a filter according to patent claim 1. Further advantageous embodiments are the subject of the subclaims or are described in more detail below. Summary of the invention

[0008] To solve this problem, a filter is proposed which has a filter housing and a filter element arranged within the filter housing. The filter housing has a filter base body and a filter cover as well as at least one inlet for unfiltered liquid metal and at least one outlet for filtered liquid metal. The filter element, which is arranged within the filter housing, has an outer circumferential surface and an inner circumferential surface as well as a filter interior for filtered liquid metal, which is at least partially delimited by the inner circumferential surface. The filter element extends along a longitudinal axis and has a first end and a second end substantially opposite the first end. Furthermore, the filter element has an opening at least at the first end, which is fluidically connected to the outlet.The filter base body and the filter cover are reversibly connectable to one another and have connecting structures which are designed such that when the filter cover is rotated relative to the filter base body, in particular about the longitudinal axis, the height of the filter housing increases or decreases along the longitudinal axis of the filter element. Detailed description of the invention

[0009] The present invention relates to a housing adaptable to a filter element for filtering liquid metals. The metals to be cast are primarily iron, iron and steel alloys, but also non-ferrous metals such as copper, nickel and / or aluminum, or alloys containing copper, nickel, aluminum and / or magnesium.

[0010] The filter according to the invention comprises a filter housing and a filter element arranged within the filter housing. The filter housing has at least one filter base and a filter cover. The filter element is preferably tubular (tubular filter element), conical (conical filter element), or truncated pyramid-shaped (truncated pyramid filter element); the filter element is particularly preferably tubular.

[0011] The filter element can be made of various materials. Typically, the filter element used in the filter according to the invention is a foam ceramic filter, which has a ceramic foam structure. Such filter elements are known from the prior art. The material of the housing parts (filter cover and filter base body) can also be of a wide variety of types, as long as it has sufficient fire resistance, abrasion resistance, and chemical and mechanical stability, each adapted to the alloy or metal used. For example, ceramic masses based on a wide variety of binders, monolithic refractory bodies, stamped, cast, pressed, shot, or 3D-printed are conceivable.It is also possible to produce them from loose bulk materials such as refractory sands and / or other natural or artificial materials, using self-curing or forced-curing binders, also using 3D printing or as a shot application (using shooting machines).

[0012] To improve fireproof, chemical, and other resistance, the housings can be provided with an additional coating, either dipped, painted, sprayed, or applied in another way. The filter housing of the filter according to the invention is preferably made of fireproof materials (so-called refractory materials). These are known to those skilled in the art.

[0013] The filter housing has at least one inlet for unfiltered liquid metal and at least one outlet for filtered liquid metal. The inlet for unfiltered liquid metal can be arranged in the filter base body or in the filter cover, and the outlet for filtered liquid metal can also be arranged in the filter base body or in the filter cover. Preferably, the inlet for unfiltered liquid metal is located in the filter base body or is arranged in the filter base body. In a further preferred embodiment, the outlet for filtered liquid metal is arranged in the filter cover or in the filter base body; more preferably, the outlet for filtered liquid metal is arranged in the filter cover. A particularly preferred filter has an inlet for unfiltered liquid metal in the filter base body and an outlet for filtered liquid metal in the filter cover.

[0014] In a further preferred embodiment, the inlet for unfiltered liquid metal is arranged completely in the main housing body. The filter housings known from the prior art are often designed in two parts with two roughly similarly dimensioned housing parts. In these known filter housings, the inlet for unfiltered liquid metal is usually designed centrally and perpendicular to the parting plane of the housing, so that the inlet is then always half in the first and half in the second half of the housing. A disadvantage of this design, however, is that experience has shown that when the two housing halves are put together, damage to the filter housing can occur, such as chipping and cracks in the refractory material. This can lead to further undesirable effects when the liquid metal flows through, such as erosion and the backfill material being washed into the system, and thus to premature blockage of the filter housing(s).of the filter elements, or the liquid material from escaping from the system. This is successfully avoided by the stable, one-piece design of the inlet without any separation. Furthermore, a more robust and resilient connection is provided between the inlet of the filter housing and the supplying pouring system, making assembly significantly easier.

[0015] The filter element is located within the filter housing, which is formed at least by the filter base body and the filter cover. The filter element, which is formed in particular from a foam ceramic, can be, among other things, a tubular body, a conical body, and / or a truncated pyramid-shaped body. Furthermore, the filter element comprises an outer surface and an inner surface. These designs have the advantage that the usable filter surface is considerably larger than that of conventional plate-shaped, flat filter elements. The filter element also has an interior filter space for filtered liquid metal. The interior filter space for receiving filtered liquid metal is at least partially delimited by the inner surface of the filter element.The filter element extends along a longitudinal axis and has at least a first end and a second end substantially opposite the first end.

[0016] The filter element additionally has an opening at least at the first end; preferably, the filter element also has a second opening at the second end. The filter element is designed such that, in a metal casting process according to the application, unfiltered liquid metal passes through the inlet of the filter housing and then impinges on the outer surface of the filter element. The unfiltered liquid metal passes through the outer surface of the filter element into the filter interior of the filter element, which is at least partially formed by the inner surface. Filtered liquid metal is then located inside the filter interior.The opening of the filter element, which is located at the first end of the filter element, is fluidly connected to the outlet of the filter housing, preferably in the filter cover, so that filtered liquid metal from the filter interior of the filter element can flow through the outlet in the filter housing, in particular in the filter cover, from the filter according to the invention into the casting mold. The filter element, in its respective form, is preferably arranged centrally in the filter housing.

[0017] The filter body and filter cover can also be designed so that the filter body has multiple receptacles for filter elements, and the filter cover is adapted accordingly. The filter body and filter cover also have the same number of outlets, adapted to the number and shape of the filter elements. The inlets and outlets in the filter housing can also be mounted on the sides, depending on the appropriate geometry of the ceramic housing.

[0018] According to the invention, the filter base body and the filter cover are reversibly connectable to one another and have connecting structures. According to the invention, the connecting structures are designed such that when the filter cover rotates relative to the filter base body, in particular about the longitudinal axis of the filter element, the height of the filter housing increases or decreases along the longitudinal axis of the filter element. This inventive design makes it possible to compensate for manufacturing tolerances of the filter elements, which usually arise due to production. The filter elements used typically have manufacturing tolerances of a few millimeters.

[0019] This can result in a situation where, when these filter elements are inserted into a conventional, state-of-the-art filter housing, the filter's filtration performance is reduced because the filter element cannot be adequately or poorly positioned within the filter housing, and unfiltered liquid metal can escape from the filter housing. However, this is undesirable, as it can significantly impair the quality of the casting process.

[0020] The connecting structures which reversibly connect the filter base body and the filter cover to one another can have different designs. Preferably, the connecting structures are designed as a support surface, wherein more preferably the support surface is designed spirally along the longitudinal axis of the filter element and / or as an inclined plane, so that upon a rotational movement of the filter cover relative to the filter base body, the height of the filter housing increases or decreases along the longitudinal axis of the filter element. Even more preferably, the support surface is designed as an inclined plane in the form of a tongue and groove, wherein the filter cover has at least one groove and / or one tongue, and wherein the filter base body has at least one groove and / or one tongue. In this preferred design, the height of the filter housing changes along the longitudinal axis when the filter cover is rotated relative to the filter base body.

[0021] The connecting structures in the form of inclined planes, in particular as a tongue and groove, are preferably arranged in opposite directions in the filter base body and in the filter cover, in particular at least two connecting structures in each case in the filter base body and in the filter cover. The connecting structures are located on each of the two housing parts (filter base body and filter cover) and, when the housing is reversibly closed, complement each other to form two inclined planes lying opposite one another, following the radius at this point, similar to a type of flat thread. This makes it possible for the distance between the two halves along the longitudinal axis of the filter element to be changed when the filter housing is closed when the two housing parts are rotated against each other.

[0022] This makes it possible to directly compensate for the previously described disadvantage of manufacturing tolerances, particularly of the filter element, at least in the height of the mostly foam ceramic filter elements, and to ensure the precise use of all parts of the system, i.e. filter element and filter housing parts, without the use of new or specially selected parts or complex reworking of the same. These tolerances of the filter element, which mostly occur in the length (height) of the filter element, can now be easily compensated for without it being necessary to individually check the filter element and housing in advance and specifically coordinate them with one another. This is made possible by the fact that by rotating the filter cover relative to the filter base body, the height of the filter housing increases or decreases along the longitudinal axis of the filter element.By shifting the connecting structures against each other in the form of inclined planes, the manufacturing tolerances of the filter element can be easily compensated, allowing the filter element to be easily positioned in the filter housing. The displacement of the connecting structures can extend over several millimeters, allowing even larger tolerances to be compensated.

[0023] Furthermore, the structural design of the inclined planes can also comprise more than just two connecting structures, for example in the form of inclined planes per filter housing part (filter cover and filter base body). Three or more of these inclined planes per filter housing part are advantageous because they have a positive effect on the stability of the housing parts relative to one another when twisted. At the end of each inclined plane, a short, horizontally running surface is preferably provided (end surfaces of the inclined planes) in order to achieve a defined end position when the full compensation distance is utilized. In principle, these inclined planes and surfaces can also have a surface structure, such as teeth or predefined locking points. This can be supported by a display or scale attached to the outside of the housing parts or incorporated into the material, for example to suitably visualize the distance between the two housing parts.

[0024] Particularly preferably, both filter housing parts have connecting structures in the form of a tongue and groove system, which is adjusted in such a way that, on the one hand, it ensures that the small opening formed when the filter cover is rotated relative to the filter base body remains effectively covered and prevents metal from escaping from the filter housing, and, on the other hand, it prevents a filler commonly used for these molds from penetrating the filter housing when the filter according to the invention is installed in the casting molds. In a preferred embodiment, the inclined planes of the tongue and groove system run on a smaller diameter within the housing than the tongue and groove system of the cover, i.e., within the tongue and groove system, and thus ensure smooth functioning as mentioned.Of course, it can also be formed in the form of an overhanging edge through the lid, so that it can then be adjusted depending on the necessary wall thickness of the housing.

[0025] In a further preferred embodiment, there can be some distance between the tongue and groove system and the inclined plane located on the smaller diameter of the housing. In one embodiment, an annular region in the filter housing around the filter element, into which liquid metal flows, does not have a constant cross-section; rather, this cross-section decreases in the direction of flow back to the inlet until it meets the open cross-section of the inlet on the inside of the housing. This point is preferably designed like a ship's bow and is intended to reconnect the circulating flow with the incoming flow with as little turbulence as possible.

[0026] The reduction of the cross-section of the channel between the filter element and the housing wall ensures that the pressure conditions in this channel are not too different, since as the metal flows into the channel around the filter element, a part flows directly into the filter element and thus ensures a decrease in volume in the annular channel.

[0027] In a further preferred embodiment, the filter housing of the filter according to the invention has at least two outlets for filtered liquid metal. In this embodiment, it is preferred that the filter element has an opening at the first end and a second opening, wherein the second opening is arranged substantially opposite (diametrically opposite) the opening at the first end of the filter element. It is further preferred that the second outlet for filtered liquid metal is arranged substantially opposite (diametrically opposite) the outlet for filtered liquid metal. It is also preferred that the second opening of the filter element is fluidly connected to the second outlet. It is particularly preferred that the outlet for filtered liquid metal is arranged in the filter cover, and that the second outlet for filtered liquid metal is arranged in the filter base body.The presence of an outlet and a second outlet allows the design effort of a casting system to be significantly reduced and the structure to be simplified. In yet another preferred embodiment, the outlet or the second outlet can be closed by a plate if the design and / or structural shape of the casting requires it. This allows for simple and rapid adaptation of the filter system to specific requirements.

[0028] In a further preferred embodiment, the inlet for unfiltered liquid metal and the filter element are fluidly connected. It is also preferred that the inlet for unfiltered liquid metal and the outlet for filtered liquid metal are arranged substantially orthogonally to one another. Further preferably, the inlet for unfiltered liquid metal is conical or has a conicity, in particular in the direction of the filter element. This embodiment ensures that, when the unfiltered liquid metal enters the filter housing, the force when the unfiltered liquid metal impacts the filter element is reduced. In particular, it can be prevented that the inflowing melt impacts the wall of the filter element directly when the housing is filled with unfiltered liquid metal.This preferred design also prevents the filter element from being damaged or even breaking.

[0029] In a further preferred embodiment, a collar is arranged around the outlet. More preferably, the collar is in contact with the outer surface or with the inner surface of the filter element. This embodiment allows the filter element arranged within the filter housing to be stably positioned and prevents the filter element from slipping within the filter housing when unfiltered liquid metal enters the filter housing through the inlet. Furthermore, this preferred embodiment prevents unfiltered liquid metal from leaving the filter through the outlet.

[0030] In yet another preferred embodiment, in which the inlet is arranged in the filter base body, and in which the filter element has an opening and a second opening substantially opposite the opening, and in which the filter housing has an outlet for filtered liquid metal in the filter cover and a second outlet for filtered liquid metal substantially opposite the outlet in the filter base body, a second collar is also arranged around the second outlet. The second collar is, in particular, configured identically to the collar.

[0031] In a preferred embodiment in which a tubular filter element is arranged in the filter housing of a preferred filter according to the invention, and in which the filter housing has an outlet for liquid filtered metal in the filter cover and a second outlet for liquid filtered metal in the filter base body, the collar and the second collar are circular in shape so that the collar and the second collar are at least partially in contact with the opening and the second opening of the filter element.

[0032] In an even more preferred embodiment, one or more filter supports, for example in the form of elevations, can be arranged around the outlet and / or around the second outlet and / or on the collar and / or on the second collar. These elevations are arranged in particular in the filter cover (outlet) and / or in the filter base body (second outlet).

[0033] These elevations can, for example, have circular geometries or can be designed in geometries that deviate from a circle, for example n-sided. In particular, these elevations are made of an elastic material, for example a malleable and / or elastic fire-resistant mass or similar. When the filter cover is rotated relative to the filter base body about the longitudinal axis of the filter element, the height of the filter housing increases or decreases along the longitudinal axis of the filter element. In this preferred embodiment, the elevations initially come into contact with the filter element when the filter housing is twisted together (twisting together means that the height of the filter housing decreases along the longitudinal axis of the filter element). This can prevent the filter element from being damaged or even breaking if the filter housing is twisted together too tightly, which is undesirable.Filter supports on the collar and / or the second collar also ensure that the filter element is stably positioned within the filter housing.

[0034] The invention is further explained by the figures, without being limited to them. Fig. 1 View of a filter according to the invention; Fig. 2 View of a filter body with inserted filter element; Fig. 3 Top view of the filter body made of Fig. 2; Fig. 4 View of a filter cover; Fig. 5 Top view of the filter cover from Fig. 4; Fig. 6 and Fig. 7 sectional views through a filter according to the invention.

[0035] Fig. 1 shows a perspective view of a filter 1 according to the invention with a filter housing 2, which has a filter cover 4 and a filter base body 3. A tubular filter element 5 (not shown) is arranged within the filter 1. An outlet 8 is arranged centrally in the filter cover 4. Below the outlet 8 is the opening 11 of the filter element 5 (not shown). Through the outlet 8, filtered liquid metal from the filter interior 10 (not shown) of the filter element 5 (not shown) can pass through the opening 11, which is fluidly connected to the outlet 8, from the filter 1 into the casting mold (not shown). An inlet 7 is arranged in the filter base body 3. The outlet 8 and the inlet 7 are arranged orthogonally to one another.The inlet 7 and the outlet 8 of the filter housing 2 each have a circumferential groove 12, which is intended to simplify the use of the filter housing with the undercasting systems commonly used in foundries, steelworks and other companies based on a wide variety of materials and manufacturing principles and ensures a quick connection. Liquid, unfiltered metal can enter the interior of the filter 1 through the inlet. When unfiltered liquid metal enters the interior of the filter housing 2, the unfiltered liquid metal strikes the filter element 5 (not shown) and diffuses through the filter element 5 into the filter interior 10 (not shown) of the filter element 5 (not shown). From the filter interior 10 (not shown) of the filter element 5 (not shown), liquid, filtered metal flows through the opening 11 and the outlet 8 into the casting mold (not shown).

[0036] Fig. 2 and Fig. 3 show a filter base body 3 as part of a filter 1 according to the invention with an inlet 7 and a tubular filter element 5 inserted into the filter base body 3. The filter element 5 has an outer surface, an inner surface, an opening 11 and a filter interior 10. The filter element 5 is surrounded on the bottom surface of the filter base body 3 by a collar 6, which is in contact with the outer surface of the filter element 5. This arrangement ensures that the filter element 5 is stably arranged in the filter base body 3. At the same time, this arrangement of collar 6 and filter element 5 prevents unfiltered liquid metal from the space for unfiltered liquid metal 9 from passing through the outlet 8 in the filter cover (not shown) into the casting mold (not shown).

[0037] This arrangement of the filter element 5 in the collar 6 ensures that only filtered liquid metal from the filter interior 10 passes through the opening 11 and the outlet 8 (not shown) into the casting mold (not shown).

[0038] The outer surface of the filter element 5 forms a closed filter surface. The filter interior 10 of the filter element 5 is formed by the inner surface of the filter element 5. When unfiltered liquid metal enters the space for unfiltered liquid metal 9 through the opening 7, the unfiltered liquid metal strikes the outer surface of the filter element 5. The unfiltered liquid metal diffuses through the outer surface of the filter element 5 into the filter interior 10 of the filter element 5, in which filtered liquid metal collects. The filtered liquid metal can then flow into the casting mold (not shown) through the opening 11 of the filter element 5, which is fluidly connected to the outlet 8 (not shown) of the filter cover 4 (not shown).The filter base body 3 has a total of three connecting structures 14 as support surfaces in the form of a tongue and groove system, which are designed as inclined planes. Each of the three connecting structures 14 of the filter base body 3 has an end surface 13 of the inclined planes.

[0039] Fig. 4 and Fig. 5 show a filter cover 4 as part of a filter 1 according to the invention with an outlet 8, through which filtered liquid metal can flow from the filter interior 10 of the filter element 5 (not shown) through the opening 11 (not shown) into the casting mold (not shown). Within the collar 6, three elevations (filter supports) 15 are arranged between the collar 6 and the outlet 8 in the filter cover 4. The elevations prevent the filter element from being damaged or even breaking if the filter housing is tightened too tightly. The filter cover 4 has, analogous to the filter base body 3 of the Fig. 2 and Fig. 3 has a total of three connecting structures 14 as support surfaces in the form of a tongue and groove system, which are also designed as inclined planes. Each of the three connecting structures 14 of the filter cover 4 has an end surface 13 of the inclined planes.

[0040] The tongue and groove system of the filter cover 4 is opposite to the tongue and groove system of the filter body 3 as shown in the Fig. 2 and Fig. 3, so that when the filter cover 4 is rotated relative to the filter base body 3, the height of the filter housing 2 increases or decreases along the longitudinal axis of the filter element 5.

[0041] Fig. 6 and Fig. 7 shows a section through a filter 1 according to the invention, having a filter housing 2 comprising a filter cover 4 and a filter base body 3. The inlet 7 as well as the outlet and the second outlet 8, 8' of the filter housing 2 each have a circumferential groove 12, which is intended to simplify the use of the filter housing with the undercast systems commonly used in foundries, steelworks and other companies based on a wide variety of materials and manufacturing principles and ensures a quick connection. A tubular filter element 5 is arranged within the filter 1. The filter element has an opening 11 and a second opening 11', which is arranged opposite the opening 11. The opening 11 is fluidly connected to the outlet 8, which is arranged in the filter cover 4 of the filter 1 according to the invention.The second opening 11' is fluidly connected to the outlet 8', which is arranged in the filter base body 3 of the filter 1 according to the invention. Unfiltered liquid metal enters the space for unfiltered liquid metal 9 through the inlet 7, which is arranged in the filter base body 3 and has a conical shape. The conical design of the inlet 7 reduces the cross-section in the direction of the filter element 5, which leads to a reduction in the flow velocity of the incoming unfiltered metal. The unfiltered liquid metal strikes the outer surface of the filter element 5 and diffuses through the outer surface of the filter element 5, so that filtered liquid metal collects in the filter interior 10 of the filter element 5. This unfiltered liquid metal then flows through the two openings 11, 11' and the two outlets 8, 8' into the casting mold (not shown).A collar 6, in which the filter element 5 is located, is arranged around each of the two outlets 8, 8'. This arrangement ensures that the filter element 5 is securely mounted in the filter housing 2. The collar 6 is in contact with the outer surface of the filter element 5.

[0042] Through this arrangement, the collar 6 prevents unfiltered liquid metal from the space for unfiltered liquid metal 9 from entering the casting mold through one of the outlets 8, 8'. The filter base body 3 and the filter cover 4 each have connecting structures 14 in the form of a tongue and groove system, wherein the tongue and groove system is formed in inclined planes. When the filter cover 4 is rotated relative to the filter base body 3, the height of the filter housing 2 changes along the longitudinal axis of the filter element 5. The Fig. 6 and Fig. The filters according to the invention shown in Figure 7 are identical with the proviso that Fig. 6 shows a filter 1 according to the invention in a minimum position, ie with a minimum height of the filter housing 2, whereas the filter shown in Fig. 7, the filter 1 according to the invention is in maximum position. List of reference symbols 1 filter 2 filter housings 3 filter base bodies 4 filter covers 5 filter element 6 collars 7 Entrance 8, 8' outlet / second outlet 9 Space for unfiltered liquid metal 10 Filter interior for filtered material 11, 11' opening / second opening 12 Circumferential groove 13 End surfaces of the inclined planes 14 connection structures 15 filter supports QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 3902151 A1

[0002] DE 4229417 C2

[0003]

Claims

[1] Filter (1) for filtering liquid metal, comprising: - a filter housing (2) and a filter element (5) arranged within the filter housing (2), - wherein the filter housing (2) comprises a filter base body (3) and a filter cover (4), - wherein the filter housing (2) has at least one inlet (7) for unfiltered liquid metal and at least one outlet (8) for filtered liquid metal, - wherein the filter element (5) comprises an outer surface and an inner surface and has a filter interior (10) for filtered liquid metal, which is at least partially delimited by the inner surface, - wherein the filter element (5) extends along a longitudinal axis and has a first end and a second end substantially opposite the first end, - wherein the filter element (5) has an opening (11) at at least the first end, - wherein the opening (11) is fluidly connected to the outlet (8), - wherein the filter base body (3) and the filter cover (4) are reversibly connectable to one another and have connecting structures (14), - wherein the connecting structures (14) are designed such that when the filter cover (4) rotates relative to the filter base body (3), in particular about the longitudinal axis, the height of the filter housing (2) increases or decreases along the longitudinal axis of the filter element (5). [2] Filter according to claim 1, wherein the inlet (7) for unfiltered liquid metal is arranged in the filter base body (3). [3] Filter according to claim 1 or 2, wherein the outlet (8) is arranged in the filter cover (4) or in the filter base body (3), preferably in the filter cover (4). [4] Filter according to one of the preceding claims, wherein the filter element (5) is a tubular body or a truncated cone-shaped body or a truncated pyramid-shaped body, preferably a tubular body, wherein the filter element is more preferably made of one or more refractory materials. [5] Filter according to one of the preceding claims, wherein the filter base body (3) and / or the filter cover (4) is made of one or more refractory materials. [6] Filter according to one of the preceding claims, wherein the inlet (7) and the filter element (5) are fluidly connected and / or wherein the inlet (7) and the outlet (8) are arranged substantially orthogonally to each other. [7] Filter according to claim 6, wherein the inlet (7) is conical, in particular in the direction of the filter element (5). [8] Filter according to one of the preceding claims, wherein a collar (6) is arranged around the outlet (8), wherein preferably the collar (6) is at least partially in contact with the outer circumferential surface or preferably with the inner circumferential surface, in particular at the opening (11). [9] Filter according to one of the preceding claims, wherein the second end has a second opening (11'). [10] Filter according to one of the preceding claims, wherein the filter housing (2) comprises a second outlet (8'), wherein the second outlet (8') is arranged substantially opposite the outlet (8), preferably in the filter base body (3). [11] Filter according to claim 10, wherein the second opening (11') is fluidly connected to the second outlet (8'). [12] Filter according to claim 10 or 11, wherein a second collar (6) is arranged around the second outlet (8'), wherein preferably the second collar (6) is in contact with the outer circumferential surface or preferably with the inner circumferential surface, in particular at the second opening (11'). [13] Filter according to one of the preceding claims, in particular according to one of claims 8 to 12, wherein one or more filter supports (15) are arranged around the outlet (8) and / or the second outlet (8'), in particular in the form of elevations, preferably between the outlet (8) and the collar (6) and / or between the second outlet (8') and the second collar (6). [14] Filter according to one of the preceding claims, wherein the connecting structures (14) are designed as support surfaces, wherein the support surfaces are preferably designed spirally and / or as an inclined plane along the longitudinal axis. [15] Filter according to one of the preceding claims, in particular according to claim 14, wherein the support surface is designed in the form of a tongue and groove, wherein the filter cover (4) has at least one groove and / or one tongue, and wherein the filter base body (3) has at least one groove and / or one tongue.

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