Filter element, filtration device and use of the filter

Abstract

The invention relates to a membrane filter element having a plate body comprising two outer sides 310, 312 extending in a flat manner and channels 330, 340 arranged inside. In order to provide a filter element having an improved filtration performance and load capacity, the plate body is produced monolithically from an open-pored ceramic material and is having a plurality of channels running between the outer sides in a longitudinal direction, each channel 330, 340 having a triangular shape in cross section and adjacent channels being separated from one another by a remaining wall 318 oriented in sections obliquely to an upward direction. The channels 330, 340 may have straight sides or convex arc shaped sides 335.

Description

[0001] Title : A filter element , a filtration device and use of the filter element

[0002] The invention relates to a filter element , in particular a membrane filter element , a filter membrane , a flat membrane and / or an immersion membrane . In particular , the filter element has a plate body which has a material , two outer sides extending in a flat manner and channels arranged next to one another between the outer sides . The invention further relates to a filtration device with the filter element and a use of the filter element . The invention further relates to a method, in particular for manufacturing the filter element , and to a method for filtration with corresponding filter elements .

[0003] Filter elements serve to filter a fluid or medium, in particular a liquid, a gas or a mixture thereof , for example to clean the medium and / or to separate substances therefrom . During filtration, a pressure loss typically occurs or a differential pressure must be applied so that the medium can penetrate the pores of the material and any filtration layer or membrane . For example , in the case of filter elements designed as immersion membranes , a negative pressure or vacuum can be applied in the interior of the filter element , from which a flow rate results . Alternatively or additionally, an external static pressure or overpressure could also be applied to achieve a flow rate . This is referred to as membrane resistance or resistance , which is the cause of the pressure loss . The resistance is decisive for the energy requirement during filtration, but also for the filtration performance of the filter element . The resistance should be kept low without reducing the ability of the filter element to reliably filter substances of certain sizes .

[0004] In order to reduce the resistance and increase the so-called flux , that is , the filtration performance as a time-related quantity or volume specification, an interaction between, for example , manufacturing costs , size of the filter element , size range of filtered substances / particles and durability must be considered . Even though a larger channel cross section can increase the flux , but this with higher space requirement and possibly higher manufacturing costs , Larger pores lead to lower resistance , but address other, in particular larger areas of filtered substances / particles .

[0005] DE 198 196 76 Al discloses a filter element with a plate body consisting of ceramic . The cross section of the filter element has channels with a circular shape - that is , circular or round channels - which point in a longitudinal direction and are arranged next to one another in a transverse direction . The plate body forms walls made of the ceramic material between the channels .

[0006] It is further disadvantageous if the mechanical strength of the filter element is too low, as the resistance of the filter element with respect to collisions and / or excessive differential pressure is then limited . If the mechanical strength is too low, the filter element may be damaged and thus become unusable .

[0007] It is the obj ect of the invention to provide a filter element , a filtration device , a use and a method, in which the disadvantages of the state of the art are avoided or reduced and an improved filtration performance and load capacity of the filter element can be realized .

[0008] This obj ect is solved by the filter element specified in claim 1 and a filtration device using it . Advantageous designs of the invention are given in the dependent claims .

[0009] A filter element according to the invention has a plate body produced monolithically by extrusion moulding or extrusion, wherein the plate has : an open-pored ceramic material ,

[0010] - two outer sides facing away from one another and each extending in a flat manner , preferably respectively in a longitudinal direction and a transverse direction, in particular at least in sections , and at least two channels running between the outer sides in a longitudinal direction and arranged next to one another in a transverse direction . With the filter element according to the invention, it is further provided that the channels respectively have a triangular shape in cross section and / or that at least two channels which are adj acent to one another are separated from one another in cross section by a wall of the plate body which is oriented in sections obliquely to an upward direction .

[0011] A filter element according to the invention is formed with an open- pored, plate-shaped and thus monolithic ceramic body manufactured by extrusion moulding or extrusion, in particular a plate body, wherein the ceramic body has channels running in the longitudinal direction and arranged next to one another in the transverse direction . According to the invention, these channels are triangular in cross section, and / or the channels are subdivided and separated from one another by walls in the ceramic body which are directed obliquely to the upward direction . This effects that the channels can be packed more densely than in the state of the art . The mechanical strength of the filter element is increased at the same time and the filtration performance of the filter element altogether in relation to the size of the filter element can be improved .

[0012] The plate body, together with any components such as material , outer sides , channels and / or walls , in particular also together with any outer filtration layer or membrane on the plate body, is manufactured monolithically, that is , made in and / or from one piece or consisting of it , which also results from the extrusion process used for manufacture . This increases the mechanical strength and manageability and reduces costs at the same time .

[0013] The plate body is permeable for the medium due to the open-pored ceramic material . In particular , the medium can be filtered from the direction of the outer sides and / or transversely to the channels , e . g . by immersing the filter element into the medium and subj ecting it to negative pressure on the channel side , whereby the medium penetrating via the outer sides , in particular at a compacted or finer filtration layer / membrane on the plate body, is filtered . Filtered medium can then be discharged via these channels . Alternatively, filtering could also be carried out from the direction of the channels towards the outer sides . The outer sides are , in particular, at least essentially flat surfaces and / or surfaces of the plate body that extend over at least sections in a flat manner . The outer sides are preferably rectangular respectively in one plane from the transverse direction and the longitudinal direction . The outer sides can be completely flat and / or parallel to one another . The outer sides are preferably at the same distance from one another everywhere , whereby a uniform, constant thickness of the filter element is specified . The outer sides extend at least essentially in a flat or in a completely flat manner , whereby an easier manufacture and maintenance of the filter element results . The filter element can then also be extruded in a particularly cost- effective and reliable process .

[0014] Each individual channel preferably has a constant cross section in the longitudinal direction with a constant , uniform clear cross sectional area, whereby preferably several channels are provided next to one another and directed in the same direction in the plate body . Adj acent channels are lined up next to one another transversely to their direction of extension; it is particularly advantageous if all channels have the same cross sectional shape with the same cross sectional area and, further , preferably respectively a constant uniform distance is selected or specified between two directly adj acent channels . The channels are particularly advantageous , in principle hollow passages running in a straight line in the plate body or in its material .

[0015] According to the invention, the channels have in particular a triangular shape in cross section through the plate body or the filter element with regard to its longitudinal extent . The triangular cross section therefore lies in the plane resulting from the transverse direction and the upward direction; it goes without saying that the transverse direction, the upward direction and the longitudinal direction are respectively oriented normal to one another .

[0016] The triangular shape is preferably understood to mean that the circumferential contour of the channels can be appropriately delimited by an ( imaginary acute-angled ) triangle , wherein the sides of the imaginary triangle are placed as close as possible to the sides of the circumferential contour or coincide in sections or even completely with the sides of the circumferential contour . In a triangular shape according to the invention, there may in particular be present three triangular shape sides , which respectively have an interior angle in corners and are directly or indirectly adj acent to one another there . The triangular shape sides can be at least in sections and / or at least essentially straight , whereas the corners are preferably formed in a rounded or curved manner . It is particularly advantageous if adj acent channels respectively have a triangular shape whose inner hollow cross section is rotated in relation to one another , in particular rotated by 180 ° in relation to one another, that is , mirror-inverted .

[0017] The triangular shape ( contour of a trigon ) of each channel , in particular paired with a mirror-inverted arrangement of adj acent channels , has the advantage that the channels can be packed more densely than would be possible with round or square channels ; with the same filter element size , triangular channels can provide a larger total filtration area , whereby the filtration performance is increased . In addition, the triangular shape ( trigon) of the channels effects that , compared to round channels , a much larger proportion of the channel can have a constant short distance to one of the two outer sides , in particular if the triangles are arranged in such a way that respectively exactly one of the three triangular shape sides extends parallel to the adj acent outer side of the filter element , whereby the membrane resistance can be reduced . At the same time , the triangular shape effects an advantageous change in the area moment of inertia of the plate body in the cross section, which is why the bending stiffness can also be increased compared to the state of the art .

[0018] A channel according to the invention is also present if at least two channels that are closest to one another or adj acent to one another are separated from one another in cross section by a wall of the plate body that is oriented in sections at an angle to an upward direction . Two correspondingly adj acent channels are then separated from each other by an oblique wall web made of the monolithic material of the plate body . The channels do not necessarily have to be separated from one another in a fluid-tight manner , as the ceramic open-pored could also allow partial fluidic communication between adj acent channels without this having an influence on the filtration performance ; "separated from one another" in this respect means at least a geometric or spatial separation . The wall or the wall web between adj acent channels therefore does not run perpendicular to the outer sides or surfaces , but at an angle to both outer sides . As the adj acent channels in the interior of the filter element are separated by oblique walls or wall webs , a support structure with oblique webs results in the interior of the filter element between the outer sides , which ensures increased stability of the structure , which is otherwise actually weakened by the channels . The oblique wall further enables in an advantageous manner that the channels overlap in sections , which enables a better use of area or volume .

[0019] Two walls remaining in the plate body in the transverse direction between adj acent channels run mirrored to one another and / or are arranged in a V-shape . This quasi zigzag arrangement of the walls effects a particular mechanical strength of the plate body, as the walls form a truss structure or strut framework between the outer sides , in particular an approximately parallel belted strut framework . Each V-shaped wall delimits a channel .

[0020] Preferably it is provided that each of the triangular shapes has three concave and / or monotonously curved corners . The corners can be arranged opposite to one another . As is usual with a triangle ( trigon ) , each rounded or curved corner forms the transition between two triangular shape sides . The corners can be formed as partial circles and / or rounded and / or with a radius or inner radius . At least one of the corners can have a radius which is between 1% and 30% of a height of an imaginary triangle delimiting the triangular shape , preferably between 10% and 20% of this height , in particular 15 % ± 2 . 5 % of this height ; in particular, two or three of the corners are formed in this manner . The channels can be arranged according to one embodiment in the plate body in such a manner that exactly one of the three triangular shape sides of a triangular shape runs parallel and adj acent to an outer side ; with a plate body with a uniform thickness , it goes without saying that this triangular shape side then also runs parallel , although at a greater distance , to the opposite outer side . The distance from the triangular shape side arranged adj acent and parallel to the outer side to this outer side can be kept constant and comparatively small , which results in a constant flow resistance between the respective outer side in question and the channel .

[0021] According to an alternate embodiment , at least two triangular shape sides , preferably all triangular shape sides of each triangular shape of the channels each have a convex arc shape , wherein further preferably the convex arc shape has a uniform radius of curvature ; in this embodiment , it is especially advantageous if the center of curvature lies on a line which bisects , in the middle , the corresponding corner of the triangular shape lying opposite to the associated triangular shape side .

[0022] According to another alternate embodiment of a filter element according to the invention, at least the mutually adj acent triangular shape sides of adj acent channels each have a non-linear shape , preferably a convex arc shape , and the walls formed between the channels have wall thicknesses which are greater near the outer sides than centrally ( or in the middle , respectively) between the outer sides .

[0023] Due to the convex curvature of the sides , the stability of the filter element is increased and the volume of each channel is increased without changing the cross-section of the entire filter element . And also , the weakening effect of each of the channels is reduced due to the arc shape form of each of the sites , which serves also for concave shaped walls between adj acent channels .

[0024] It is preferably provided that the triangular shapes have at least a first triangular shape , whose area of gravity is preferably arranged closer to the first outer side than to the second outer side . At the same time , at least a second triangular shape is provided, whose area of gravity is preferably arranged closer to the second outer side than to the first outer side . This can be achieved particularly easily in that adj acent channels are or can be formed between the outer sides respectively rotated by 180 ° to one another . In particular, in an advantageous configuration, the first and second triangular shapes can be provided alternately along the transverse direction . In the particularly preferred configuration, the first triangular shapes and the second triangular shapes are geometrically similar or are formed with an identical shape cross section, even if they are arranged mirror-inverted . The basic shape of the two triangular shapes can be an isosceles triangle , although other triangular shapes are also possible .

[0025] The triangular shapes can be selected in such a manner that a height measured along the upward direction of an imaginary triangle which abuts the three triangular shape sides of one of the triangular shapes in sections can be determined, wherein the centre of the height lies on a centre line between the outer sides and / or wherein the heights are regularly spaced apart from one another in the transverse direction by a distance . This also ensures a uniform filtration with regard to the even use of the outer surfaces per se and the outer surfaces in comparison to one another . It is further preferably provided that respectively two triangular shape sides of the triangular shapes have a first interior angle between 40 ° and 80 ° , preferably 60 ° ± 1 ° and / or that two triangular shape sides of the triangular shapes respectively have a second interior angle and a third interior angle , which are of equal size to one another and are preferably between 40 ° and 80 ° , wherein in particular preferably the three triangular shape sides of all triangular shapes form an equilateral triangle , whereby an interior angle of 60 ° results respectively .

[0026] An extruded filter element can have any length in the longitudinal direction; a width of the filter element in the transverse direction is limited by the tool and can for example be between 50 mm and 500 mm. With mutually parallel outer sides and flat outer surfaces formed by these , a thickness of the filter element in the upward direction between 2 mm and 50 mm can be provided, preferably between 5 mm and 25 mm, and preferred between 7 . 5 mm and 12 . 5 mm, in particular amounting to 10 mm ± 2 mm . A quotient of the width of the filter element in the transverse direction to the thickness of the filter element in the upward direction can for example be between 1 and 20 , whereby the quotient can particularly preferably be between 7 and 13 . The filter element can only have a limited number of channels , which is preferably in the range of 10 to 50 , in particular in a range of 18 and / or in a range of 18 ± 6 .

[0027] The filter element has two longitudinal outer sides arranged facing away from one another in the transverse direction; it is particularly advantageous for these to be convex and / or at least substantially circular in cross section, in particular semicircular . Hereby, the two longitudinal outer sides form a seamless transition to the respective adj oining outer side .

[0028] The plate body can additionally be provided with a filtration layer , in particular on at least one or both outer sides . The filtration layer is preferably provided enveloping both the outer sides and the longitudinal outer sides . The filtration layer is in particular an outer filtration layer . The outer filtration layer can consist of the same material as the plate body, but preferably has a higher fineness ; hereby, certain, in particular coarser dirt particles can already be filtered out or retained on the surface of the plate body without clogging the material or the substrate forming the plate body .

[0029] The above obj ect is also solved by a filtration device , preferably for the filtration or filtering of a medium present in liquid and / or gaseous form. The filtration device has the filter element described above and a housing with a chamber for a medium . The housing can have a suction connection fluidically connected to the channels of the filter element for the medium filtered in particular by the filter element . The filter element can be immersed in the chamber and / or subj ected to negative pressure by means of the channels . The invention can also consist in the use of the filter elements .

[0030] The invention could also have a procedural aspect . The method can in particular be a method for manufacturing the filter element .

[0031] The method can be used to manufacture and provide an improved filter element . The procedural aspects can consist in particular in that an open-pored and / or open-pored-curable ceramic material is provided for forming a plate body, and / or that the plate body or a preform for the plate body is extruded from the ceramic material in a longitudinal direction; and / or that when the material is extruded, outer sides facing away from one another, longitudinal outer sides facing away from one another, interior channels and walls between channels are formed in one piece in the material ; and / or the channels in cross section can have a triangular shape , and / or the walls remaining in the plate body between the channels are V-shaped when viewed in the transverse direction and / or are arranged obliquely to an upward direction or are formed during extrusion .

[0032] The method can be carried out using a manufacturing tool , wherein the manufacturing tool preferably has sections or parts in a triangular shape for forming the triangular channels ; the channels can thereby be formed uniformly and continuously in the longitudinal direction within the plate body by means of extrusion .

[0033] Further features and advantages of the invention will be apparent from the following description of preferred embodiments of the invention shown in the drawings . In the drawings :

[0034] Fig . 1 shows a filter element known from the state of the art in sectional view transverse to the longitudinal direction with circular channels ;

[0035] Fig . 2 shows a filter element according to a first embodiment of the invention in sectional view transverse to its longitudinal direction with triangular channels ; Fig . 3 shows a detailed view of the filter element from fig . 2 ;

[0036] Fig . 4 shows a filter element according to the invention, cut in the longitudinal direction, in a perspective view;

[0037] Fig . 5 schematically shows a very simplified a filtration device for filtering a medium;

[0038] Fig . 6 shows a filter element according to a second embodiment of the invention in sectional view transverse to its longitudinal direction with triangular channels having convex bowed sides ; and

[0039] Fig . 7 shows an enlarged view of one ofe the channels of the second embodiment .

[0040] Fig . 1 shows a filter element 102 known form the art with a plate body 104 in a section transverse to the longitudinal extension of the filter element known from the state of the art . The plate body 104 has a predetermined width in a transverse direction X and extends uniformly with basically arbitrary lengths in a longitudinal direction Z extending into the image plane in an elongated or planar manner . In a height direction Y , the filter element 102 is essentially flat and has correspondingly only a small thickness . The plate body 104 consists of a ceramic material 106 . The plate body 104 has a flat outer side 112 on the top side . The plate body 104 has a flat outer side 110 on the bottom side . In the interior of the plate body 104 are located fourteen channels 130 , each of which is delimited by the ceramic material 106 . Walls 118 formed from the ceramic material 106 remain between the channels 130 . The channels 130 have a circular shape in cross section or are circular or round in cross section . Compared to the outer side 112 and the outer side 110 , the channels 130 with their hollow walls thus have a plurality of different distances . Each channel 130 has the smallest distance to the outer side 110 or 112 at only one point of the hollow wall , whereas the distance increases along the circular curvature of the channel wall to the centre of the plate body 104 .

[0041] Fig . 2 shows a filter element 2 according to a first embodiment of the invention with a plate body 4 manufactured monolithically by means of extrusion or extrusion moulding . The plate body 4 consists of an open- pored ceramic material 6 and forms two outer sides 10 , 12 facing away from one another and respectively extending in a flat manner . A total of eighteen hollow channels 30 , 40 are formed in the interior of the plate body 4 , which channels run between the outer sides 10 , 12 in a longitudinal direction Z and are arranged adj acent to one another in a transverse direction X .

[0042] Each channel of the channels 30 , 40 has respectively a triangular shape 32 , 42 . Thereby, first channels 30 are assigned in an adj acent manner to the first outer side 10 and second channels 40 to the second outer side 12 , as respectively one of their flat sides or triangular shape sides 34 , 44 is arranged closer to the respective outer side 10 , 12 , and also parallel to this outer side 10 . Between two channels 30 , 40 arranged adj acently in the interior of the plate body 4 , remains a wall 18 of the plate body 4 which wall is directed in sections obliquely to an upward direction Y and which separates adj acent channels 30 , 40 from one another . Based on the altogether eighteen channels 30 , 40 , seventeen walls 18 consequently result between the channels 30 , 40 .

[0043] The channels 30 have a first triangular shape 32 , which is positioned in the interior of the plate body 4 in such a manner that a flat side or triangular shape side 34 runs adj acent and aligned in parallel to the first outer side 10 at the bottom in figure 2 ; the channels 40 have a second triangular shape 42 , which is positioned in the interior of the plate body 4 in such a manner that a flat side or triangular shape side 44 runs adj acent and aligned in parallel to the second outer side 12 at the top in figure 2 . Between adj acent channels 30 , 40 , a wall 18 respectively results or remains between the outer sides 10 , 12 , wherein each wall 18 runs obliquely with regard to a plane spanned by the upward direction Y and the transverse direction Q, wherein the walls 18 assigned to the same channel 30 or 40 are V- shaped to one another. The walls thus form a zigzag pattern in the sectional plane shown, wherein this zigzag pattern continues over the entire longitudinal extent in the direction Z . Between the channels 30, 40, therefore, a strut framework results by means of the V-shaped walls, which framework is particularly robust with respect to surface loads in the upward direction Y, that is, with respect to surface loads that act across the width of the plate body 4 on the outer surface (s) of the plate body 4 resulting on the outer sides 10, 12.

[0044] The walls 18 have a uniform wall thickness 20 among themselves, at least in the area of adjacent channels 30, 40 in which the triangular channels 30, 40 form flat lateral triangular shape sides 35 and 45 that run obliquely to the upward direction. The wall thickness 20 can vary in particular depending on the material 6 used, the number and cross sectional area of the channels 30, 40 and can be, for example, in the range from 1 mm to 10 mm.

[0045] The plate body 4 further has a width, which is predetermined by the manufacturing tool, for example, between two longitudinal outer sides 14, 16 arranged facing away from one another in the transverse direction X; on the longitudinal outer sides 14, 16, the outer side 10 respectively merges into the outer side 12, and vice versa. The longitudinal outer sides 14, 16 are convex in cross section, exactly semicircular in the exemplary embodiment shown. The longitudinal outer sides 14, 16 merge smoothly into the outer sides 10, 12. One of the channels 30, 40 is respectively adjacent to one of the longitudinal outer sides 14, 16. In the exemplary embodiment shown with an even number of eighteen channels 30, 40, a channel 30 with the triangular shape 32 is adjacent to one longitudinal outer side 14, and a channel 40 with the triangular shape 42 is adjacent to the opposite longitudinal outer side 16. With a plate body with an odd number of channels, one channel with the identical or identically aligned triangular shape could respectively lie adjacent to one of the longitudinal outer sides. As can be seen in particular from fig. 3, which shows an enlarged section of fig. 2 with only one channel 30 and one channel 40 respectively, all triangular shapes 32, 42, irrespective of their orientation, have three concave and monotonously curved corners 38, 48, wherein the corners 38, 48 lie opposite one another within a triangular shape 32, 42. Each of the three corners 38, 48 of each triangular shape 32,42 respectively has a radius which is 15% ± 2% of a height 52 of an imaginary triangle 50 delimiting the triangular shape 32, 42.

[0046] Exactly one of the three triangular shape sides 34, 44 of each of the triangular shapes 32, 42 extends parallel to both outer sides 10, 12 and is directly adjacent to one of the two outer sides 10, 12. A first outer side distance 66 of the triangular shape side 34 results to the outer side 10, and a second outer side distance 68 of the triangular shape side 44 results to the outer side 12. The outer side distance 66 has the same size as the outer side distance 68, and on a plate body 4, as shown in figure 2, all channels 30 have the outer side distance 66 with the triangular shape side 34 facing the outer side 10, and all channels 40 have the outer side distance 68 with the triangular shape side 44 facing the outer side 12. The outer side distance 66, 68 can again vary depending on the material 6 used, the thickness of the plate body 4 and the size of the channels 30,40 and can be in a similar range as the wall thickness 20 of the walls 18 between the channels 30, 40, for example in the range from 1 mm to 10 mm. The two further triangular shape sides 35, 45 of each of the triangular shapes 32, 42 run obliquely to the upward direction and obliquely to the two outer sides 10, 12.

[0047] Each second triangular shape 32 of the triangular shapes 32, 42 is arranged with its area centre of gravity 36 closer to the first outer side 10 than to the second outer side 12. Each second triangular shape 42 of the triangular shapes 32, 42 is arranged with its area centre of gravity 46 closer to the second outer side 12 than to the first outer side 10. The respective area centre of gravity 36, 46 is determined by the side bisectors 64 of the opposing, oblique triangular shape sides 35, 45. In the first triangular shape 32, the area centre of gravity 36 lies below a centre line 28 and in the second triangular shape 42 , the area centre of gravity 46 lies above the centre line 28 , wherein the centre line 28 extends centrally between the outer sides 10 , 12 and parallel thereto or at a constant distance therefrom.

[0048] Viewed in the transverse direction X, the first and second triangular shapes 32 , 42 are arranged alternately . The first and second triangular shapes 32 , 42 are arranged mirrored to one another with respect to a plane spanned by the longitudinal direction Z and the transverse direction X . The triangular shapes 32 , 42 are provided in such a way that a height 52 of the imaginary triangle 50 measured along the upward direction Y can be determined . The centre 54 of the height 52 lies on the centre line 28 between the outer sides 10 , 12 . The heights 52 are regularly spaced at a distance 62 from one another in the transverse direction X .

[0049] A first interior angle 56 of the imaginary triangle 50 is 60 ° . A second interior angle 58 of the imaginary triangle 50 and a third interior angle 60 of the triangle 50 have the same size and are 60 ° respectively . The imaginary triangle 50 is therefore isosceles as well as equilateral . The respective interior angle 56 , 58 , 60 of the imaginary triangle 50 corresponds to the interior angle between the respective walls of the hollow wall of the channels 30 , 40 or to the angle of the respective adj acent triangular shape sides 34 , 35 or 44 , 45 ; the triangular shape sides 35 , 45 of adj acent triangular shape sides 32 , 42 extending obliquely to the upward direction Y or to the thickness 24 of the plate body 4 are hereby parallel to one another in such a manner that these adj acent triangular shape sides 35 , 45 of the channels 30 , 40 form the wall 18 with a constant thickness between them.

[0050] It can be particularly expedient for constant load conditions if the thickness of the wall 18 between the obliquely running triangular shape sides 35 , 45 of the channels 30 , 40 is approximately the same size as the outer side distance 66 of the triangular shape sides 34 from the underside 10 and the outer side distance 68 of the triangular shape sides 44 from the outer side 12 . This also ensures a constant flow resistance for the medium to be filtered in the area of all channels 30 , 40 . Partially uneven material thicknesses of the substrate or material 6 for the plate body 4 result only in the area of the longitudinal outer sides 14 , 16 .

[0051] Fig . 4 shows a spatial configuration of a filter element 2 or a plate body 4 with an interior cross section with eighteen channels 30 , 40 between the outer sides 10 , 12 according to fig . 2 and fig. 3 in an exemplary manner . A length 26 in the longitudinal direction Z can for example be 300 mm . A width 22 in the transverse direction X can for example be 105 mm . A thickness 24 in the upward direction Y can for example be 10 mm. The width 22 and the thickness 24 are specified with the tool used during manufacture , the length 26 however can be designed as desired for a filter element manufactured by extrusion . With the above dimensions results ratio or quotient of the width 22 and the thickness 24 of approximately 10 . 5 . By changing the tools of the manufacturer, different widths and thicknesses and a different number of channels can also be realized .

[0052] The filter element 2 or the plate body 4 is in particular formed in a plate shape with a thickness 24 that remains the same over the entire longitudinal extent . The plate body 4 consists monolithically of the material 6 . In the exemplary embodiment according to figure 4 , the filter element 2 has two end faces 80 , which are arranged facing away from one another in the longitudinal direction Z , which are cut off or deflected vertically and which are correspondingly flat and arranged transversely to the outer surfaces 10 , 12 . The channels 30 , 40 can be accessed on these end faces 80 in order to remove the filtered medium (permeate ) . The outer sides 10 , 12 respectively extend in a flat manner, are flat and are arranged parallel to one another .

[0053] The plate body 4 can be provided on the outer sides 10 , 12 and on the longitudinal outer sides 14 , 16 with an outer filtration layer 8 , preferably an open-pored filtration layer . The filtration layer 8 can, for example , have a thickness of only approximately 200 micrometres , but a thickness of 500 micrometres or more is also possible . The ceramic material 6 remaining in the interior of the plate body 4 immediately delimits each of the channels 30 , 40 .

[0054] The ceramic material 6 can in particular consist of a ceramic with carbide , such as silicon carbide . Materials made of or with oxide , in particular aluminium oxide , titanium oxide , zirconium dioxide , magnesium oxide or zinc oxide , are also conceivable . Mixtures of at least one carbide and at least one oxide are also conceivable in order to achieve material-specific synergies during filtration .

[0055] A filter element according to the invention with triangular , alternately arranged channels 30 , 40 has a particularly favourable ratio of material volume to channel volume . The filter element according to the invention can therefore prove to be more efficient than the known filter elements with circular channel cross sections . The filtering area of the channels 30 , 40 according to the solution according to the invention is also larger than in the previously known channels 130 with a circular shape ( see fig. 1 ) , as the packing density at the channels 30 , 40 can be realised in a significantly higher manner . This effects a higher flux or a lower pressure loss during filtration . By using triangular channels with a positioning in such a manner that respectively one channel with a flat side is parallel to one of the outer sides also results in a very advantageous reduction of an interior membrane resistance or internal resistance , as the filtration path between the outer sides and the channel is minimized . It can prove to be particularly advantageous to maintain a smallest possible distance to the next outer surface over a largest possible flat side of each channel .

[0056] Fig . 5 shows a filtration device 200 in an exemplary manner in which a filter element 2 according to the invention is used . The filtration device 200 uses a filter element 2 according to the invention and has a housing 202 with a chamber 204 for filtering the medium 210 . The dimensions of the filter element 2 are selected in such a manner that the filter element 2 can be inserted into the housing 202 and can there immerse into the medium 210 to be filtered . The housing 202 in turn has a suction connection 206 for the medium 210 filtered through the filter element 2 as permeate , which suction connection is fluidically connected to channels 30 , 40 of the filter element 2 .

[0057] With the filtration device 100 , a medium 210 can be filtered, in particular a liquid and / or gaseous medium 210 .

[0058] Fig. 6 shows a filter element 302 according to a second embodiment with a plate body 304 in the same view as in Fig . 2 . The plate body 304 again is manufactured monolithically by means of extrusion or extrusion moulding . The plate body 304 consists of an open-pored ceramic material 306 and forms two outer sides 310 , 312 facing away from one another . The two outer sides 310 , 312 have small distance compared to the width of the plate body 304 , thus the plate body is extending in a flat manner with only a small thickness . The plate body 304 has a flat outer side 312 on the top side and a flat outer side 310 on the bottom side . In the interior of the plate body 304 are located five channels 330 and four channels 340 , each of which is delimited by walls 318 consisting of the ceramic material 306 and remaining between adj acent channels 330 and 340 . Obviously, the number of channels 330 , 340 could be higher ( or smaller ) . The channels 330 , 340 have generally a circular shape in cross section with rounded corners 338 , 438 , and the general shape of both channels 330 , 340 is identic , only the orientation of the channels 340 is rotated by 180 ° compared to the channels 330 .

[0059] Thereby, the first channels 330 are assigned in an adj acent manner to the first outer side 310 and the second channels 340 to the other outer side 312 , as respectively one of triangular shape sides 334 of the channels 330 is closer to the bottom side 310 while one of the triangular shape sides 344 of the other channels 340 is arranged closer to top side 312 , compared to the two other sides 335 , 345 of each of the channels 330 , 340 . Between adj acent channels 330 , 340 remains a wall 318 of the plate body 304 which wall is directed in sections obliquely to the top and bottom sides 310 , 312 . The walls 318 separate adj acent channels 330 , 340 from one another . Based on the altogether nine channels 330 , 340 , in the drawing , eight walls 318 will remain between the channels 330 , 340 . The channels 330 have a first triangular shape 332 , positioned such in the interior of the plate body 304 that the bottom triangular shape side 334 runs adj acent and aligned to the bottom outer side 310 , while the channels 340 have a second triangular shape 342 , which is positioned such that the triangular shape side 344 runs adj acent and aligned to the top outer side 312 in Fig . 6 . The walls 318 again form a zigzag pattern in the sectional plane shown, wherein this zigzag pattern continues over the entire longitudinal extent of each plate body 304 . Between the channels 330 , 340 , therefore , a strut framework results by means of the V-shaped walls 318 .

[0060] Deviating from the first embodiment as shown in Fig . 2 , all the triangular shape sides 334 , 335 from the triangular shaped channels 330 and all the triangular shape sides 344 , 345 from the triangular shaped channels 340 are not straight but instead our arc shape bowed in convex manner, i . e . each have convex arc shape . This shape is even better visible from Fig . 7 , in which only one channel 330 is shown . As can be seen, each triangular shape sides 334 , 335 comprises a convex arc shape with constant radius R of curvature . The center of the said radius R of curvature is positioned such that it lies on a line which bisects , in the middle , the corresponding corners 338 of the triangular shape 332 of the said channels 330 between the sides 334 , 335 lying opposite to the associated triangular shape side 335 . Due to the convex arc shape , as is clearly visible from Fig . 6 , each remaining wall 318 between adj acent channels 330 , 340 has a varying thickness being smaller in the middle plane between the top side 312 and the bottom side 310 than in those regions , being closer to the top side 312 and the bottom side 310 . The concave curvature of the wall 318 significantly increases the stability of each of the walls 318 , so that the plate body 304 and the filter element 302 has an increased resistance against pressure compared to the first embodiment . Also , the varying thickness of the wall 318 increases the filtering effect , since each of the channels has a wider cross-section compared to an embodiment with flat triangular sides . The figures did not show an embodiment where only two sides of the channel comprise an arcute convex bowed configuration, while the third side of each tringular shaped channel , preferably the side lying parallel to the top or bottom side could also be of straight or linear configuration as shown in the first embodiment instead of having convex bowed configuration . As a further alternative not shown, the mutually adj acent triangular shape sides of adj acent channels each could have a non-linear shape , like a V-shape with large angle between 160 and 179 degrees , or a convex arc shape , and the walls formed between the channels have wall thicknesses which are greater near the outer sides ( top and bottom sides ) of the plate like filter element than centrally ( or in the middle , respectively) between the outer sides . Again, such walls between adj acent channels increase the stability of the plate like filter element against pressure difference or load, protecting the channels not to be damaged on such loads . Further amendments will be visible for the person s killed in the art .

Claims

Claims :

1. Filter element (2; 302) with a plate body (4) produced monolithically by extrusion, wherein the plate body (4) comprises: an open-pored ceramic material (6) , two outer sides (10, 12) facing away from one another and extending in a flat manner respectively, and at least two channels (30, 40) running between the outer sides (10, 12) in a longitudinal direction (Z) and arranged next to one another in a transverse direction (X) , characterized in that the channels (30, 40) respectively have a triangular shape (32, 42) in cross section and / or that at least two channels (30, 40) next to one another are separated from one another by a wall (18) which runs in sections obliquely to a upward direction (Y) of the plate body (4) .

2. The filter element (2) according to the preceding claim, characterized in that two walls (18) next to one another in the transverse direction (X) are arranged mirrored and / or V-shaped to one another with respect to a plane spanned by the upward direction (Y) and the longitudinal direction (Z) .

3. The filter element (2) according to one of the preceding claims, characterized in that each triangular shape (32, 42) has three concavely and / or monotonously curved corners (38, 48) , wherein preferably at least one of the corners (38; 48) has a radius which is between 1% and 30% of a height (52) of an imaginary triangle (50) delimiting the triangular shape (32, 42) , preferably between 10% and 20% of this height (52) , in particular 15% ± 2, 5% of this height ( 52 ) .

4. The filter element (2) according to one of the preceding claims, characterized in that exactly one of the three triangular shape sides (34, 44) of a triangular shape (32, 42) runs in parallel to an outer side (10, 12) , preferably to both outer sides (10, 12) , wherein the two further triangular shape sides (35; 45) of eachtriangular shape (30; 40) preferably run obliquely to both outer sides ( 10 , 12 ) .

5. The filter element (2) according to one of the preceding claims, characterized in that the triangular shapes (32, 42) have at least a first triangular shape (32) , whose area centre of gravity (36) is arranged closer to the first outer side (10) than to the second outer side (12) , and / or that the triangular shapes (32, 42) have at least one second triangular shape (42) , whose area centre of gravity (46) is arranged closer to the second outer side (12) than to the first outer side (10) .

6. The filter element (2) according to claim 5, characterized in that the first and second triangular shapes (32, 42) are arranged alternately along the transverse direction (X) .

7. The filter element (2) according to claim 5 or 6, characterized in that the first and second triangular shapes (32, 42) are arranged mirrored to one another with respect to a plane spanned by the longitudinal direction (Z) and the transverse direction (X) .

8. The Filter element (302) according to one of claims 1 to 3, or 5 to 7, characterized in that at least two triangular shape sides (334, 335; 344, 345) , preferably all triangular shape sides (334, 335; 344, 345) of each triangular shape (332, 342) each have a convex arc shape, wherein further preferably the convex arc shape has a uniform radius of curvature (R) , the center of curvature of which lies on a line which bisects, in the middle, the corresponding corner (338; 348) of the triangular shape (332, 342) opposite the associated triangular shape side.

9. The filter element (102) according to one of claims 1 to 3, or 5 to 7, characterized in that at least the mutually adjacent triangular shape sides (334, 335; 344, 345) of adjacent channels (330) each have a non-linear shape, preferably a convex arc shape, and the walls (318) formed between the channels (330) have wallthicknesses which are greater near the outer sides (310, 312) than centrally between the outer sides (310, 312) .

10. The filter element (2) according to one of the preceding claims, characterized in that the triangular shapes (32, 42) are provided in such a manner that a height (52) , measured along the upward direction (Y) , of an imaginary triangle (50) which abuts the three triangular shape sides (34,35; 44,45) of one of the triangular shapes (32, 42) in sections can be determined, wherein the centre (54) of the height (52) lies on a centre line (28) between the outer sides (10, 12) and / or wherein the heights (52) are regularly spaced apart from one another in the transverse direction (X) by a distance ( 62 ) .

11. The filter element according to one of the preceding claims, characterized by two triangular shape sides (44, 45) of the triangular shapes (32, 42) having a first interior angle (56) between 40° and 80°, preferably 60° ± 1° and / or that two triangular shape sides (34,35; 44,45) of the triangular shapes (32, 42) respectively have a second interior angle (58) and a third interior angle (60) , which are of equal size to one another and are preferably between 40° and 80°, wherein in particular preferably the three triangular shape sides (34,35; 44,45) of all triangular shapes (32, 42) form an equilateral triangle.

12. The filter element (2) according to one of the preceding claims, characterized by a thickness (24) in the upward direction (Y) between 2 mm and 50 mm, preferably between 5 mm and 25 mm, particularly between 7.5 mm and 12.5 mm, in particular of 10 mm ± 2 mm.

13. The filter element (2) according to one of the preceding claims, characterized by a ratio of a width (22) in the transverse direction (X) and a thickness (24) in the upward direction (Y) between 1 and 20, preferably between 5 and 15, particularly preferably between 7 and 13, and in particular preferably at 10 ± 2, and / or characterized by a number of channels (30, 40) , which ispreferably in the range of 10 to 50, in particular in the range of18 ± 6.

14. The filter element (2) according to one of the preceding claims, characterized by two longitudinal outer sides (14, 16) arranged facing away from one another in the transverse direction (X) , wherein at least one of the longitudinal outer sides (14, 16) is formed convex and / or at least essentially circular arc-shaped, in particular semicircular in cross section.

15. The filter element (2) according to one of the preceding claims, characterized in that the outer sides (10, 12) are arranged at least substantially flat and / or parallel to one another.

16. A filtration device (200) , characterized by a filter element (2) according to one of the preceding claims and a housing (202) with a chamber (204) for a medium (210) , wherein the housing (202) has a suction connection (206) for the medium (210) filtered through the filter element (2) connected fluidically with the channels (30, 40) of the filter element (2) .

17. The use of a filter element (2) according to one of claims 1 to 16 for the filtration of an in particular liquid and / or gaseous medium (210) , wherein the filter element is preferably used in a filtration device according to claim 14.

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