DE102012012941A1 - Method for preparing ceramic filter element used for e.g. water purification, involves winding web layer around ceramic material impregnated bobbin which is burned and sintered to form ceramic filter element - Google Patents

Abstract

The method involves forming web layer (20) containing three support webs (21-23) made of combustible material. The first and second channels (31,32) intended for the formation of fluid flow channels and permeate fluid channels respectively, are formed between respective support webs and extended between end faces (24,25) of web layer. The second channels and support web (23) are closed between two end faces of web layer by a ceramic adhesive. The web layer is wound around a ceramic material impregnated bobbin (30) which is burned and sintered to form ceramic filter element. An independent claim is included for ceramic filter element.

Description

Technical area

The invention relates to a method for producing a ceramic filter element for filtering fluids and to a ceramic filter element for filtering fluids.

State of the art

From the WO 2006/005668 discloses a method of manufacturing a ceramic filter element in an exhaust gas filter for internal combustion engines in the form of a diesel soot filter or catalyst carrier. Here, a combustible, non-ceramic carrier web is first soaked with a ceramic slip and then burned out in the desired geometric shape until the carrier web is burned and a rigid filter body is formed. The carrier web may consist of synthetic material of organic material, for example cellulose, in particular paper. Preferably, the carrier web is brought into the desired shape before impregnation with the ceramic slurry, which is maintained during the soaking and subsequent firing. A smooth paper carrier web and a corrugated paper carrier web are laminated to form a semi-finished product with the formation of gas channels and then spirally rolled up to form an approximately cylindrical filter body which forms a wound filter. By continuously introducing a ceramic adhesive on the wavy surface of the wavy paper web not only an adhesive bond with the smooth paper web, but at the same time the flow channels are closed at one end on one end face with the ceramic adhesive, which is required so that the exhaust gas flows through the filter body radially.

From the EP 1 930 060 A1 For example, a method of manufacturing a diesel particulate filter comprising a layered, laminated ceramic filter body for filtering an exhaust gas flow of a diesel engine has become known. In this case, a corrugated fibrous web and a smooth fibrous web with formation of gas flow channels are alternately superimposed with respect to its layering direction to form the layered filter body. In the circumferential direction adjacent gas flow channels are mutually closed on an inflow side or on an outflow side of the wound filter by sealing plug made of ceramic material. The closed on the outflow gas channels represent input side gas channels, while the closed on the input side gas channels represent output side gas channels. By the mutual closing of the adjacent gas channels, a backflow effect accompanies the inflow of the exhaust gas, which forces the exhaust gas flowing through the inlet side gas passages through porous filter sections of the channel gas separating the input side gas channels from the output side gas channels in a transverse direction into the output side gas channels, from where the filtered exhaust gas flows out to the outflow side out of the outlet-side gas channels. The cross section of the input side gas passages continuously decreases in a direction from the inflow side to the outflow side, while the cross section of the output side gas passages increases continuously in the same direction. The filter body is made of at least one ceramic impregnated fiber web, in particular of paper, so formed by temperature sintering that the fibers of the fiber material are baked, and wherein the ceramic material is sintered together to form a continuously porous between its two surfaces and gas-permeable filter section, wherein at least one fiber web is corrugated to form the gas channels and layered to form the filter body in several layers.

• – eine höhere thermische Stabilität von bis zu mehr als 800 Grad Celsius,
• – eine höhere chemische Stabilität mit vorteilhaften Einsatzmöglichkeiten in einem PH-Bereich von 0 bis 14,
• – eine bessere mechanische Abriebfestigkeit,
• – eine bessere physikalische Beständigkeit, beispielsweise gegenüber UV-Strahlen und/oder Ozon,
• – eine höhere Druckstabilität, insbesondere bezüglich hoher Rückspüldrücke,
• – bessere und effektivere Reinigungsmöglichkeiten und
• – eine längere Lebensdauer.

Winding modules with polymer membranes for filtering liquids with "cross-over-filtration" have been part of the general state of the art for many years. Ceramic-based winding modules are only used on a laboratory scale because of their hitherto very complicated, complicated and very expensive production based on a technology using ceramic films. In addition, due to the mechanical and processing properties of ceramic films, the performance in terms of winding size, packing and channel density of polymeric winding membrane modules can not be achieved by far. Winding membrane modules are characterized by significantly lower investment costs for the filter module and by their many times higher packing density of about 300 to 1000 m ² / m ³ compared to tube and flat membrane geometries. In addition, winding modules can be operated with a significantly lower energy consumption due to the low required overflow. However, ceramic membranes have considerable advantages over polymer membranes, in particular

• - a higher thermal stability of up to more than 800 degrees Celsius,
• A higher chemical stability with advantageous applications in a pH range of 0 to 14,
• A better mechanical abrasion resistance,
• A better physical resistance, for example to UV rays and / or ozone,
• A higher pressure stability, in particular with regard to high backwashing pressures,
• - better and more effective cleaning options and
• - a longer life.

The invention has for its object to provide a method for producing a ceramic filter element for filtering fluids, especially liquids, to provide, which is simple and inexpensive to use and with the filter elements for filtering fluids, especially liquids, simple and inexpensive can be produced, which combine the advantageous material properties of ceramic with the advantages of the winding geometry of a winding module and with which new applications are possible, which have so far failed the polymeric winding modules. The invention is also based on the object of providing a filter element for filtering fluids, in particular liquids, which is simple and inexpensive to produce, which combines the advantageous material properties of ceramics with the advantages of the winding geometry of a winding module and with them new applications are possible, which have so far failed the polymeric winding modules.

Disclosure of the invention

This object is achieved by the features of claims 1 and 8.

Accordingly, the invention relates to a method for producing a ceramic filter element for filtering fluids, in particular liquids, for example water, wherein first a web layer of at least three layers superposed carrier webs is prepared, each of a combustible material, preferably from an organic and or synthetic material, preferably with or consisting of, in particular natural, fibers, in particular of cellulose or cotton, preferably made of paper and / or at least one polymer, of which at least one first carrier web, preferably to form a release layer or barrier layer is designed as a flat track and is and of which a second carrier web preformed to form fluid flow channels, preferably corrugated or preformed to form other, for example triangular or square, fluid flow channels or channel geometries, executed rt, is or is, and of which a third carrier web is provided for forming a permeate removal layer for removing a fluid permeate, preferably designed as a flat web is or, wherein the second carrier web between the designed as a flat track first carrier web and the the third carrier web is arranged or is, wherein the at least three carrier webs, preferably by means of a ceramic adhesive, are glued or together, wherein in the bonded together state between the designed as a flat track first carrier web and the preformed second carrier web more to form fluid flow channels for the filtering fluid provided first channels are formed, which are bounded by wall portions of the first carrier web and wall portions of the second carrier web, which are open to facing away from each other end faces of the web layer and which, preferably continuously, between the two end faces of the web layer in e extend in the channel direction, and wherein between the preformed second carrier web and the third carrier web or between the preformed second carrier web and an intermediate therebetween and the third carrier web intermediate carrier web, preferably designed as a flat web or is more, to form permeate fluid channels provided second channels are formed, which are bounded by wall portions of the second carrier web and wall portions of the third carrier web or the intermediate carrier web and extending between the end faces of the web position substantially in the same channel direction as the first channels or substantially parallel to the extend first channels, wherein both the second channels and the third carrier web are each closed in the region of the two end faces of the web layer by means of a ceramic adhesive, and that, preferably subsequently, the web layer to one, preferably substantially parallel to the channel Direction extending, axial axis is spirally wound into a winding body, wherein subsequent to the winding or before winding to the winding body, the at least three carrier webs with a liquid or pasty ceramic material, in particular with a ceramic slip, are impregnated, after which with the ceramic material impregnated winding body is burned out and sintered, preferably subsequently, in particular at the opposite elevated temperatures, to an inherently stable, in particular rigid, preferably separately manageable, ceramic winding body having a plurality in the axial direction to the two end faces open and extending in the axial direction ceramic fluid flow channels for The fluid to be filtered as well as several extending in the axial direction, sealed in the region of the two end faces, ceramic permeate fluid channels for the permeate and having a ceramic permeate Abtranspo rt layer for removing the permeate, preferably in a Abtransportrichtung transversely to the axial axis, in particular in the direction of the axial axis, has.

Such a filter element is particularly simple and inexpensive to produce with the inventive method and combines in the advantageous material properties of ceramic with the advantages of the winding geometry of a winding module and also allows new applications that have so far failed the polymeric winding modules. Compared to prior art polymeric winding modules, such a filter element has a significantly larger filter surface and thus packing density, in particular when the second carrier web is of a wavy design. Examples of possible applications include water treatment, wastewater treatment, recycling, chemical and biotechnical applications as well as applications in the food and beverage industry.

According to an advantageous embodiment it can be provided that first the first carrier web is glued to the second carrier web and then the third carrier web is glued to the second carrier web or that first the second carrier web is glued to the third carrier web and then the first carrier web with the second Bonded carrier web or that the first carrier web and the second carrier web and the second carrier web and the third carrier web are glued together in one step and / or simultaneously.

According to a development it can be provided that it is assumed that a third carrier web is already closed with a ceramic adhesive in the region of two of its end faces pointing away from one another, and that this third carrier web, which is already closed at the end, is glued to the second carrier web or the third carrier web is first glued to the second carrier web and then the third carrier web in the region of two of their facing away from each other end faces is sealed with a ceramic adhesive.

According to a particularly advantageous embodiment, it can be provided that for the front end closing the second channels a ceramic adhesive paste in the form of two, preferably continuous, Kleberaupen transverse, preferably perpendicular to the channel direction on the first channels bounding wall portions of the second carrier web on their from the wherein the third carrier web and the second carrier web are pressed against each other, whereby at the same time a front-end closing of the second channels in the region of its two end faces is effected. As a result, the production can be further simplified and even more cost-effective.

Alternatively, it may be provided that the end face-side closing of the second channels a ceramic adhesive paste in the form of two, preferably continuous, Kleberaupen is applied to that side of the third carrier web, which limits the second channels in the finished web layer, and / or then with the the adhesive beads provided third carrier web, with the Kleberaupen ahead, is pressed together with the second carrier web, whereby a stirnendseitiges closing of the second channels in the region of its two end faces is effected.

However, it goes without saying that, according to a further alternative, the second channels bounded by the second carrier web and by the third carrier web can first be produced, and only then can these second channels in the region of the two end faces of the web layer be closed with a ceramic adhesive. However, this procedure is more expensive and more expensive than the two alternatives mentioned above.

It is also understood that the second channels and the third carrier web can be closed in a method step and / or simultaneously in the region of the two end faces of the web layer with a ceramic adhesive. As a result, the production can be further simplified, which can achieve further cost savings.

According to a very particularly preferred embodiment, it may be provided that the wall portions of the first carrier web and the second carrier web delimiting the first channels are coated with a liquid or pasty ceramic material before or after firing and / or sintering on the inside of the channel to form a membrane layer Forming a membrane layer can be impregnated with a pasty or liquid ceramic material. As a result, the filter performance or the filter quality of the filter element can be adjusted particularly effectively.

To form such a membrane layer, the liquid or pasty ceramic material which can be used for this purpose can be introduced into the first channels preferably through channel openings of the first channels, in particular through channel openings, from which the first channels lead to the end sides of the layer layer. Thereby, the manufacturing process can be further simplified and carried out more cheaply.

According to a very particularly preferred embodiment, it can be provided that the liquid or pasty ceramic material for forming the membrane layer contains ceramic particles whose mean particle size or grain size is smaller than an average particle size or grain size of particles of the ceramic material, with which the second carrier web is impregnated. The ceramic material for forming the membrane layer may preferably have an average particle or grain size in the range of about 1 to 5000 nanometers, preferably about 1 to 800 nanometers. To form a membrane for microfiltration (MF), the average particle size or grain size of the ceramic material may be about 200 to 5000 nanometers, preferably about 200 to 800 nanometers. To form a membrane for ultrafiltration (UF), the average particle size or grain size of the ceramic material may be about 20 to 200 nanometers. To form a membrane for nanofiltration (NF), the average particle or grain size of the ceramic material may be about 1 to 20 nanometers. An NF membrane can also be designed or be based on sol-gel. The particle or grain size of the ceramic material for the carrier layers can be, for example, depending on the particular application in the range of 50 to 30,000 nanometers, preferably from 200 to 2000 nanometers, or bimodal or multimodal mixtures thereof. The liquid or pasty ceramic material, for example in the form of a ceramic slip, can be used as constituents, in particular particles, for example of aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZTO ₂ ), titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), silicon carbide ( SiC), silicates, zeolites or mixtures thereof.

According to a preferred embodiment it can be provided that the third carrier web is produced from a combustible fabric, mesh and / or nonwoven and / or transversely, preferably substantially perpendicular to the axial axis, in the circumferential direction, preferably over at least one winding circumference, in particular substantially over an entire winding length of the third carrier web, continuous, provided for the formation of permeate fluid flow transverse channels transverse channels. As a result, after firing and sintering of the impregnated with the fluid or pasty ceramic material third carrier web to a ceramic permeate removal layer, the latter have a correspondingly large permeability to the permeate, resulting in a particularly easy and effective removal of the permeate, preferably in the direction on the axial or longitudinal or central axis of the bobbin, allows a minimum pressure loss.

According to a particularly preferred embodiment, it can be provided that the first channels, viewed in an imaginary sectional plane perpendicular to the channel direction, preferably viewed in their channel direction in each case continuously, have a larger channel cross-section than the second channels. As a result, an even larger filter surface and thus even greater packing density can be realized in the sintered filter element. Accordingly, in the sintered filter element, the fluid channels for the fluid to be filtered, which emerge from the first channels, may have a larger cross section than the cross section of the permeate removal channels for removing the permeate, which emerge from the second channels.

The invention also relates to a ceramic filter element in the form of a substantially cylindrical or oval wound body for filtering fluids, in particular liquids, for example water, in particular produced by the process according to the invention, the or at least one spirally around one or the Axial axis coiled formed layer layer consists of a plurality of interconnected both by sintering and by sintering intrinsically stable, preferably rigid, formed ceramic layers between which a plurality of fluid flow channels are formed for a fluid to be filtered and a plurality of permeate fluid channels for a fluid permeate, wherein the fluid flow channels and the permeate fluid channels each extend in a channel direction in one or the axial direction, preferably in a longitudinal direction of the winding body, substantially parallel to each other, and wherein the ceramic Sch one, preferably made of the impregnated with a ceramic material third carrier web, ceramic permeate removal layer for transporting away the permeate, preferably in a Abtransportrichtung transverse to the axial direction, in particular in the direction of the axial axis, and one, preferably from the a porous separating layer made of a ceramic material impregnated second carrier web for filtering the fluid to be filtered, which separates the fluid flow channels of the permeate fluid channels, as well as one, preferably made of the impregnated with a ceramic material first carrier web, ceramic, further, preferably for the comprising a fluid-permeable, porous separating layer to be filtered and filtered, or a barrier layer, preferably impermeable to the filtered and filtered fluid, which extends at a radial distance to the permeate-transporting layer, and wherein the fluid flow channels le and the permeate fluid passages of the layer layer, as viewed in the radial direction, are arranged between the further separating layer and the permeate transport layer or between the barrier layer and the permeate transport layer, and wherein the fluid flow passages facing away from each other in the axial direction End sides of the filter element are open, and wherein both the permeate fluid channels and the permeate removal layer are each closed in the region of both end faces of the filter element by a sintered ceramic material or by a sintered ceramic closure body, and wherein the fluid flow channels for the to be filtered fluid on the one hand, in radial Direction to a first surface side of the filter element, bounded by the limited with substantially flat surface parts further separating layer or barrier layer extending in a winding circumferential direction, preferably continuously, over the spirally wound layer layer formed, and wherein the fluid flow channels on the other hand, in a counter set direction to a side facing away from the first surface side second surface side of the filter element, is bounded by one or the step or wave-shaped channel wall of the separation layer, and wherein the permeate fluid channels for the permeate on the one hand, toward the first surface side of the step or wave-shaped channel wall of the separating layer is limited, which extends in the winding circumferential direction, preferably continuously, over the spirally wound layer layer formed, and wherein the permeate fluid channels on the other hand, in the direction of the two surface, from a, preferably with substantially flat surface parts delimited, further, preferably made of the impregnated with a ceramic material intermediate carrier web, porous, ceramic layer or of the, preferably limited with substantially flat surface parts, permeate removal Layer be limited.

According to a particularly preferred embodiment, it can be provided that the step-like or wave-shaped channel wall of the separating layer is formed or provided on its channel defining the fluid flow channels with a, preferably sintered, ceramic membrane whose average membrane pore size is smaller than a mean substrate pore size a membrane-supporting substrate material of said channel wall. As a result, the filter performance or the filter quality of the filter element can be adjusted particularly effectively.

Furthermore, it can preferably be provided that the fluid flow channels, viewed in an imaginary sectional plane perpendicular to the channel direction, preferably viewed continuously in the channel direction, have a larger channel cross-section than the permeate fluid channels. As a result, a filter element with an even larger filter surface and thus even greater packing density can be realized.

Brief description of the drawings

Further advantages, features and details of the invention will become apparent from the following description in which embodiments of the invention are explained in more detail with reference to the drawings.

It is understood that the person skilled in the art can regard the above features and the features resulting from the claims and from the drawings within the scope of feasibility not only in combination but also individually and / or in meaningful further combinations.

Show it:

1 A schematic and perspective view of a web layer which is wound into a winding body;

2 an enlarged cross section of the web layer according to 1 ;

3 a perspective view of a sintered ceramic filter element in the form of a substantially cylindrical bobbin for filtering fluids.

4 an enlarged section with partial section of the filter element according to 3 ,

Embodiments of the invention

For the production of in the 3 and 4 shown filter element for filtering fluids, in particular liquids, such as water, which is designed as a sintered, intrinsically stable, rigid bobbin, can proceed as follows:
It is initially a railway 20 from at least three layers superimposed carrier webs 21 . 22 . 23 produced. These at least three carrier webs 21 . 22 . 23 are or are each made of a combustible material, which in the embodiment shown is paper, in particular raw paper. From the said three carrier webs 21 . 22 . 23 is or is a first carrier web 21 designed as a flat track, the formation of a filter to be filtered and filtered fluid 65 . 67 permeable separating layer 41 or to form a fluid to be filtered and filtered 65 . 67 impermeable barrier layer 41 is provided. A second carrier web 22 of the three carrier webs 21 . 22 . 23 is or is to form fluid flow channels 51 corrugated preformed. It can, for example, as in 2 illustrates being sinusoidally wavy. It is understood, however, that the second carrier web 22 also be stepped and / or trapezoidal preformed or designed or can be. Of the three carrier webs 21 . 22 . 23 is a third carrier web 23 for the formation of a permeate transport layer, which can also be referred to as a "permeate spacer" 43 for the removal of a fluid permeate 67 intended. This third carrier web 23 is or is designed in the embodiment shown as a flat track. For the third carrier web 23 Particularly suitable are comparatively thick, coarse-fiber webs of natural or synthetic fibers, for example of cellulose, cotton nets or coarse nonwovens of synthetic or natural materials.

The permeate removal layer may also be realized by applying to a carrier web, preferably the same as the carrier web 21 is constructed, continuous beads, with a width of, for example, 0.5 mm to 50 mm and a height of, for example, 0.3 mm to 5 mm, of ceramic adhesive across the channels 31 , be applied at a distance, preferably from 1 mm to 200 mm. These adhesive beads are compressed during winding, with the distance of the Kleberaupen slightly reduced as a result of their compression. The adhesive beads then serve as spacers between adjoining web layers 20 and thus produce the permeate transport layer. These adhesive beads can also be a cohesion of adjacent web layers 20 cause. If the adhesive beads in addition to the two end faces of the carrier web 23 attached, they serve there at the same time for closing the permeate removal layer. The open areas between the glue tracks serve to remove the permeate.

The permeate removal layer can alternatively also be realized as follows: Continuous strips, with a width of, for example, 0.5 mm to 50 mm and a height of, for example, 0.3 mm to 3 mm, made of the same material and with the same structure as the carrier web 23 become transverse to the channels 31 at a distance, preferably from 1 mm to 200 mm, on a carrier web 23 , preferably the same as carrier web 21 is constructed, applied and glued with ceramic adhesive. The strips serve as spacers between adjacent web layers 20 and thus produce the permeate transport layer. In addition, the strips are also on the two end faces of the carrier web 23 attached, they serve there at the same time for closing the permeate removal layer. The open areas between the strips serve to remove the permeate.

To form the railway layer 20 becomes the corrugated second carrier web 22 between the designed as a flat track first carrier web and also designed as a flat track third carrier web 23 arranged. In the finished course situation 20 are the three carrier webs 21 . 22 . 23 glued together by means of a ceramic adhesive.

In the finished course situation 20 are between the designed as a flat track first carrier web 21 and the corrugated second carrier web 22 several for forming fluid flow channels 51 for the fluid to be filtered 65 provided first channels 31 educated. These first channels 31 are of wall parts of the first carrier web 21 and wall portions of the second carrier web 22 limited. Further, the first channels 31 to the two facing away from each other end faces 24 . 25 the railway situation 20 open. They extend continuously between the two end faces 24 . 25 the railway situation 20 in a channel direction 26 essentially parallel to each other. In addition, in the finished railway layer 20 between the corrugated second carrier web 22 and designed as a flat track third carrier web 23 several to form permeate fluid channels 52 provided second channels 32 educated. These second channels 32 are of wall parts of the second carrier web 22 and wall portions of the third carrier web 23 limited. The second channels 32 extend between the two end faces 24 . 25 the web layer substantially parallel to each other and substantially in the same channel direction 26 like the first channels 31 , ie essentially parallel to the first channels 31 , Unlike the first channels 31 become the second channels 32 each closed in the region of two of their facing away from each other end faces by means of a ceramic adhesive. To form the finished course layer 20 becomes the arrangement of the second carrier web 22 and the third carrier web 23 with the second channels in between 32 arranged such that in the finished web layer 20 the second channels 32 each in the area of the two end faces 24 . 25 the railway situation 20 are closed by means of the ceramic adhesive. This is in 2 indicated by hatching. Also the third carrier web 23 is closed in each case in the region of two of their facing away from each other end faces by means of a ceramic adhesive. The third carrier web is used to form the finished web layer 23 arranged such that in the finished web layer 20 the third carrier web 23 in the area of the two end faces 24 . 25 the railway situation 20 are closed by means of the ceramic adhesive. This is in 2 also indicated by a hatching.

For end-side closing of the second channels 32 may be a pasty ceramic mass, preferably a ceramic adhesive paste, for example in the form of two adhesive beads, transverse to the channel direction 26 on the first channels 31 delimiting wall parts of the corrugated second carrier web 22 , on her from the first carrier web 21 away side, be applied. The two glue beads are in the channel direction 26 the second channels 32 considered at a distance from each other on the corrugated second carrier web 22 applied. In this case, a first adhesive bead in the region of a first end side of the corrugated second carrier web 22 applied to this and the second adhesive bead is in the region of the first end face facing away from the second end face of the second carrier web 22 applied to these. The application of the two adhesive beads preferably takes place simultaneously. It is understood, however, that the adhesive beads also successively on the second carrier web 22 can be applied. After applying the two adhesive beads on the second carrier web 22 but preferably at the same time or in one process step with the application of the adhesive beads on the second carrier web 22 , become the third carrier web 23 and the second carrier web provided with the adhesive beads 22 pressed together. This is a front-end closing of the second channels 32 effected in the area of its two end faces, so that subsequently the second channels 32 are closed on all sides, each recess or release a channel cavity of the respective second channel 32 ,

The layer layer produced in this way 20 or even during their production, the railway situation 20 around a substantially parallel to the channel direction 26 the first and the second channels 31 . 32 extending axial axis 27 spiraling to a winding body 30 wound. This is schematically in 1 illustrated. For this purpose, therefore, the railway situation 20 according to their winding accordingly bendable or flexible.

Following the winding or even before winding to the winding body 30 , is the railway situation 20 or wound with this winding body 30 infiltrated or impregnated with a ceramic slip. This may preferably be a liquid provided with ceramic particles or grains, preferably in the form of a suspension. At the finished course location 20 which the at least three carrier webs 21 . 22 . 23 contains, so it may be a burn-out support structure for the ceramic slurry.

In order to obtain a filter capable of forming a winding membrane with respect to certain filtration applications, the first channels are preferably subsequently 31 with a ceramic separating layer 28 to form a membrane 48 Mistake. This may again preferably be a ceramic slurry or a liquid provided with ceramic particles or grains, in particular a suspension. The liquid or pasty ceramic material is preferably through channel openings, from which the first channels 31 to the front ends 24 . 25 the railway station out, in the first channels 31 brought in. In other words, the first channels 31 for the purpose of forming the ceramic separation layer 28 with the liquid or pasty ceramic material to form the membrane 48 be flooded. The liquid or pasty ceramic material for forming the membrane layer 28 contains ceramic particles whose average particle size is smaller than an average particle size of particles of the ceramic material, with which at least the second carrier web 22 impregnated.

The finished course situation 20 is in cross section in 2 shown. It has the said three carrier webs 21 . 22 . 23 , So designed as a flat track first carrier web 21 , which also designed as a flat track, preferably with respect to the first carrier web 21 thicker, third carrier web 23 and between the first carrier web 21 and the second carrier web 22 arranged, corrugated, second carrier web 22 and optionally the membrane layer 28 on that on the first channels 31 facing inside of the first carrier web 21 and the second carrier web 22 can be provided or is. After winding the course layer 20 to the winding body 30 and after treatment, in particular impregnation or impregnation, of the wound body 30 with the ceramic slurry, the bobbin retains 30 its geometric shape, so that after curing or burning a bobbin 50 is obtained, the shape of the shape of the not yet cured or not fired bobbin 30 equivalent. Preferably, the desired shape of the bobbin 50 achieved or maintained without post-processing. The sintering shrinkage can be between 0 and 30% in all three spatial directions.

The wound with the ceramic slurry or provided bobbin 30 is then dried first. Subsequently, the carrier structure, which can also be referred to as a "template", is first burned out, preferably at temperatures below 500 degrees Celsius. Subsequently, or in a continuous heating process, the temperature is sintered to a firing temperature for sintering by firing the remaining ceramic structure, preferably at temperatures above 1000 degrees Celsius, to an inherently stable, rigid, separately handled, ceramic wound body or solidified by sintering operations. It is also possible to first convert the template into carbon via a pyrolysis step and then burn it out under oxidizing conditions.

It is understood that the formation of a membrane 48 provided ceramic separating layer 28 can also be applied only after drying, but before burning out or after burning out, but before sintering. In the above cases one also speaks of "co-firing". It is also understood that to form a membrane 48 provided ceramic separating layer 28 can also be applied only after sintering. In this case, the one with the ceramic separating layer 28 provided, already sintered ceramic winding body again exposed to corresponding firing temperatures, whereby the membrane layer 28 to a ceramic membrane 48 sintered and at the same time with the channel walls of the previously sintered first channels 31 firmly connected.

An exemplary embodiment of a ceramic filter element produced by the method described above 50 in the form of a sintered, ceramic, substantially cylindrical bobbin 50 for filtering fluids 65 , in particular of liquids, for example of water, is in 3 shown. Its ceramic structures are as a section of the 3 in the form of a partial section in the 4 shown. In the sintered bobbin 50 the term "bobbin" is to be understood in the sense that this by winding of aufwickelbaren materials, here the web layer 20 , is made.

The sintered bobbin 50 has as essential elements more in the axial direction 47 to the two sides facing away from each other 44 . 45 open and in the axial direction 47 extending ceramic fluid flow channels 51 for the fluid to be filtered 65 on. The winding body 50 also has several in the axial direction 47 extending, in the region of the two end faces 44 . 45 the bobbin 50 sealed, ceramic permeate fluid channels 52 for the permeate 67 on. The winding body 50 also has a ceramic permeate removal layer 43 for the removal of the permeate 67 in a Abtransportrichtung transverse to the axial axis 27 and toward the axial axis 27 towards.

The ceramic filter element 50 consists of at least one spiral around an axial axis 47 wrapped layer layer formed 40 , The spiral layer layer 40 consists of a plurality of ceramic layers fixed to one another by sintering as well as by sintering which are inherently stable and rigid 60 ; 61 . 62 . 63 , In other words, it may be in the filter element 50 a sintered to a one-piece ceramic structure filter body with a spiral layer structure act.

Between the layers integrally connected by sintering 60 ; 61 . 62 . 63 are several, also as feed channels for a zuzuführendes, to be filtered fluid ("Feed") markable, fluid flow channels 51 for the fluid to be filtered 65 and a plurality of permeate fluid channels 52 for a fluid permeate 67 educated. In the permeate 67 it is that by means of filter structures of the filter element 50 , preferably by means of a membrane 48 of the filter element 50 , filtered fluid, or to a flowable residue. The fluid flow channels 51 and the permeate fluid channels 52 each extend substantially straight in a channel direction 26 substantially parallel to each other in the axial direction 47 and thus in the longitudinal direction of the bobbin 50 ,

The ceramic layers 60 ; 61 . 62 . 63 the layer layer 40 as a wound body 50 manufactured filter element 50 include one for the filtered and filtered fluid 65 . 67 permeable separating layer 41 or one for the filtered and filtered fluid 65 . 67 impermeable barrier layer 41 , a permeate transport layer 43 for the removal of a permeate 67 and a release layer 42 for filtering the fluid to be filtered 65 , The separation layer 42 separates the fluid flow channels 51 from the permeate fluid channels 52 or separates them from each other. The separation layer 42 is formed of two co-sintered layers, namely one of the fluid flow channels 51 immediately delimiting porous membrane layer 48 and from a membrane layer 48 supporting, corrugated, porous substrate layer 49 , How out 4 can be seen, have both the substrate layer 49 as well as the membrane layer 48 , viewed in the circumferential direction or spiral circumferential direction, a sinusoidal corrugated structure. Accordingly, the release layer 42 , viewed in the circumferential direction or spiral circumferential direction, a total of a sinusoidal corrugated structure 57 on.

The ceramic, sintered separating layer 41 or barrier layer 41 is from the impregnated with a ceramic slip first carrier web 21 produced. The ceramic, sintered separating layer 42 is from the impregnated with a ceramic slip second carrier web 22 and the release layer preferably applied thereon 28 for the membrane 48 made, which is also impregnated with a ceramic slurry or formed or produced. The ceramic, sintered permeate removal layer 43 is from the impregnated with a ceramic slurry third carrier web 23 produced. The permeate removal layer 43 extends at a radial distance to the separation layer 41 or to the barrier layer 41 ,

The fluid flow channels 51 and the permeate fluid channels 52 the layer layer 40 are, viewed in the radial direction, between the separation layer 41 or the barrier layer 41 and the permeate transport layer 43 arranged. The fluid flow channels 51 are to those in the axial direction 47 facing away from each other end faces 44 . 45 of the filter element 50 open on both sides. In contrast, both the permeate fluid channels 52 as well as the permeate removal layer 43 each in the area of both end faces 44 . 45 of the filter element 50 sealed by sintered ceramic material.

The fluid flow channels 51 for the fluid to be filtered 65 on the one hand, in the radial direction to a first surface side of the filter element 50 . here radially outwardly, viewed from the limited with substantially flat surface parts separating layer 41 or barrier layer 41 limited. The separation layer 41 or barrier layer 41 extends in a winding or spiral circumferential direction or -laufrichtung continuously over the layer layer 40 , On the other hand, the fluid flow channels 51 for the fluid to be filtered 65 , in an opposite direction, to a second surface side of the filter element facing away from the first surface side 50 towards, ie radially inwardly, viewed from a wavy channel wall of the separation layer 42 limited.

The permeate fluid channels 52 for the permeate 67 are on the one hand, in the direction of the first surface side, so here radially outward, considered, of the wavy channel wall of the separation layer 42 limited. This wave-shaped channel wall or separating layer extends continuously in the winding or spiral circumferential direction or circumferential direction over the spirally formed layer layer 40 , On the other hand, the permeate fluid channels 52 , viewed in the direction of the second surface side, that is to say radially inwardly, from the permeate removal layer bounded by substantially flat surface parts 43 limited.

The wave or sinusoidal channel wall of the separation layer 42 or the separating layer 42 is on her the fluid flow channels 51 delimiting channel inside with a sintered ceramic layer in the form of a membrane 48 educated. The membrane 48 has a mean membrane pore size that is less than an average substrate pore size of the membrane 48 carrying substrate material 49 the channel wall parts of the respective fluid flow channel 51 ,

The spirally formed layer layer 40 consists of several, considered in the radial direction, superimposed layers 60 ; 61 . 62 . 63 , These layers 60 ; 61 . 62 . 63 are each basically constructed as above for the entire layer layer 40 described. Due to the spiral structure or formation of the layer layer 40 the sintered ceramic filter element 50 , adjacent to a permeate removal layer 43 an outer layer 61 the superimposed layers 60 ; 61 . 62 . 63 , viewed in a direction radially inward, immediately a release layer 41 or barrier layer 41 a next inner layer 62 of said layers 60 ; 61 . 62 . 63 at. As a result of the sintering process, the respective permeate removal layer 43 and the immediately radially inwardly adjacent separating layer 41 or barrier layer 41 sintered together, thus forming a common, one-part layer 53 out.

If the layer 41 as a separating layer 41 is formed, that membrane surface, which is connected to the permeate-transport layer 43 adjacent, so in the illustrated embodiment, the flat bottom of the sine wave, also contribute in full to the filtration. In this case, a barrier layer can or must only on the outside of the outermost layer 61 of the ceramic filter element produced as a wound body 50 be provided. Preferably, the porous separating layer should 41 be at least as permeable to the fluid to be filtered as the substrate material of the porous substrate layer 49 or should have the same structure.

The processes involved in filtering a fluid to be filtered 65 by means of a filter element according to the invention 50 in which the layer 41 as a barrier layer 41 is formed, can be described as follows: The fluid to be filtered 65 becomes a first end face 44 fed to the winding membrane, which then a arrival or inflow 44 formed. From there, the fluid to be filtered 65 into and through the fluid flow channels 51 flow. As the fluid flow channels 51 are open on both sides, not just to the first front page 44 or on arrival or inflow side, but also to the second end facing away from it 45 the filter element, a proportion of the fluid or a flowable residue or a fluid retentate 66 at the then a discharge or outflow side 45 forming second end face 45 of the filter element 50 from the fluid flow channels 51 escape. While flowing through the fluid flow channels 51 can be the fluid to be filtered 65 in directions transverse to the axial direction 47 or channel direction 26 the fluid flow channels 51 , through the wave or sinusoidal separating layer 42 pass through, and therefore first through the membrane layer 48 and then through the supporting substrate layer 49 , In this case, the components to be filtered by means of the membrane 48 filtered out of the fluid, so that in the fluid flow channels 51 the retentate 66 , So the filtered-out constituents or residues, is or are held back. That through the membrane layer 48 and this supporting substrate 49 the wavy separation layer 42 passed through filtered fluid 67 is in the permeate fluid channels 52 added. Since the permeate fluid channels 52 in the area of the two front sides 44 . 45 of the filter element 50 , so on both sides, are tightly closed, the filtered fluid 67 can not escape there, but can from the permeate fluid channels 52 in a direction transverse to the channel direction 26 the permeate fluid channels 52 and viewed inwardly, in the adjacent, at least porous, but preferably in the circumferential or spiral circulation direction, in particular continuously extending, channels, such as microchannels, having, permeate-transport layer 43 hike. Since the permeate removal layer 43 in the region of the two end faces 44 . 45 of the filter element 50 , so on both sides, is tightly sealed and further, there to the permeate-transport layer 43 looking radially inward, the barrier layer 41 adjacent, not only for the fluid to be filtered 65 but also for the filtered fluid 67 impermeable, the filtered fluid 67 neither in the axial outward direction, nor in the radial direction inward, from the permeate fluid channels 52 but can pass through the pores or channels of the spirally formed permeate removal layer 43 through, in the circumferential or spiral circulation direction, in 3 in one direction 54 counterclockwise, to the inner end 55 the permeate removal layer 43 migrate where the filtered fluid in the form of a permeate 67 can escape. It is understood that the outer end 56 at least the permeate removal layer 43 but preferably the entire outermost layer 61 the layer layer 40 can be tightly closed, preferably. by means of a sintered ceramic closure 64 ( 3 ). To this closure 64 To realize ceramic material may be in the form of a ceramic adhesive prior to sintering in the region of the outer ends 36 the railway situation 20 have been applied. This can also fix the outer end 36 the as a winding body 30 wound up railway layer 20 be achieved.

As in already 1 schematically illustrates the web layer 20 to form a wound body 30 on a, preferably ceramic, central tube 37 be wound up. The central tube 37 has in a longitudinal extension region, in the axial direction 47 from the winding body 30 . 50 or filter element 50 is covered, several openings in the 1 not shown. Through these openings through the can from the permeate-transport layer 43 effluent permeate 67 in the central tube 37 flow in which the permeate 67 collected and from which the permeate 67 can be routed away.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The 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

• WO 2006/005668 [0002]
• EP 1930060 A1 [0003]

Claims (10)

Method for producing a ceramic filter element ( 50 ) for filtering fluids ( 65 ), whereby first a web layer ( 20 ) of at least three layered carrier webs ( 21 . 22 . 23 ), each made of a combustible material, of which at least one first carrier web ( 21 ) is designed as a flat track or is and of which a second carrier web ( 22 ) for forming fluid flow channels ( 51 ) is or is preformed, and of which a third carrier web ( 23 ) to form a permeate removal layer ( 43 ) for the removal of a fluid permeate ( 67 ) is provided, wherein the second carrier web ( 22 ) between the first carrier web ( 21 ) and the third carrier web ( 23 ) is arranged, wherein the at least three carrier webs ( 21 . 22 . 23 ) are glued together or are, wherein in the bonded together state between the designed as a flat track first carrier web ( 21 ) and the preformed second carrier web ( 22 ) several to form fluid flow channels ( 51 ) for the fluid to be filtered ( 65 ) provided first channels ( 31 ) formed by wall parts of the first carrier web ( 21 ) and wall parts of the second carrier web ( 22 ), which are facing away from each other end faces ( 24 . 25 ) of the railway layer ( 20 ) are open and between the two end faces ( 24 . 25 ) of the railway layer ( 20 ) in a channel direction ( 26 ), and wherein between the preformed second carrier web ( 22 ) and the third carrier web ( 23 ) or between the preformed second carrier web of an intermediate carrier web lying between the latter and the third carrier web, a plurality of for forming permeate fluid channels ( 52 ) provided second channels ( 32 ) formed by wall parts of the second carrier web ( 22 ) and wall parts of the third carrier web ( 23 ) or the intermediate carrier web are limited and between the end faces ( 24 . 25 ) of the railway layer ( 20 ) substantially in the same channel direction ( 26 ) like the first channels ( 31 ), whereby both the second channels ( 32 ) as well as the third carrier web ( 23 ) in each case in the region of the two end faces ( 24 . 25 ) of the railway layer ( 20 ) are closed by means of a ceramic adhesive, and that the web layer ( 20 ) about an axial axis ( 27 ) spirally to a winding body ( 30 ) is wound, wherein subsequent to the winding or before winding to the winding body ( 30 ) the at least three carrier webs ( 21 . 22 . 23 ) are impregnated with a liquid or pasty ceramic material, after which the wound with the ceramic material wound body ( 30 ) burned out and to an inherently stable ceramic wound body ( 50 ) is sintered, the more in the axial direction ( 47 ) to its two end faces ( 44 . 45 ) and in the axial direction ( 47 ) extending ceramic fluid flow channels ( 51 ) for the fluid to be filtered ( 65 ) as well as several in the axial direction ( 47 ) extending, in the region of the two end faces ( 44 . 45 ) sealed, ceramic permeate fluid channels ( 52 ) for the permeate ( 67 ) and a ceramic permeate removal layer ( 43 ) for the removal of the permeate ( 67 ) having. Method for producing a ceramic filter element ( 50 ) according to claim 1, characterized in that it is assumed that a third carrier web, which is already closed in the region of two of their facing away from each other end faces with a ceramic adhesive, and that then this already frontally sealed third carrier web is glued to the second carrier web or that the third carrier web is first glued to the second carrier web and then the third carrier web in the region of two of their facing away from each other end faces is sealed with a ceramic adhesive. Method for producing a ceramic filter element ( 50 ) according to claim 1 or 2, characterized in that for front-end closing of the second channels ( 31 ) a ceramic adhesive paste in the form of two adhesive beads transversely to the channel direction ( 26 ) to which the first channels ( 31 ) delimiting wall parts of the second carrier web ( 22 ) on its from the first carrier web ( 21 ), whereby and / or after which the third carrier web ( 23 ) and the second carrier web ( 22 ) are pressed together, whereby at the same time a front-end closing of the second channels ( 32 ) Is effected in the region of its two end faces or that for front end closing of the second channels a ceramic adhesive paste in the form of two adhesive beads on that side of the third carrier web is applied, which limits the second channels in the finished web layer, and / or then with the the adhesive beads provided third carrier web, with the adhesive beads advance, is pressed together with the second carrier web, whereby a front-end closing of the second channels in the region of its two end faces is effected. Method for producing a ceramic filter element ( 50 ) according to one of the preceding claims, characterized in that the first channels ( 31 ) delimiting wall parts of the first carrier web ( 21 ) and the second carrier web ( 22 ) before or after firing and / or sintering channel inside to form a membrane layer ( 28 . 48 ) coated with a liquid or pasty ceramic material and / or to form a membrane layer ( 28 . 48 ) are impregnated with a pasty or liquid ceramic material. Method for producing a ceramic filter element ( 50 ) according to claim 4, characterized in that the liquid or pasty ceramic material through channel openings from which the first channels ( 31 ) to the end faces ( 24 . 25 ) of the railway layer ( 20 ) into the first channels ( 31 ) is introduced. Method for producing a ceramic filter element ( 50 ) according to claim 4 or 5, characterized in that the liquid or pasty ceramic material contains ceramic particles whose mean particle size is smaller than an average particle size of particles of the ceramic material, with which the second carrier web is impregnated. Method for producing a ceramic filter element according to one of the preceding claims, characterized in that the first channels, viewed in an imaginary sectional plane perpendicular to the channel direction, have a larger channel cross-section than the second channels. Ceramic filter element ( 50 ) in the form of a substantially cylindrical or oval wound body ( 50 ) for filtering fluids ( 65 ), in particular that produced by a method according to one of the preceding claims, consisting of at least one spiral around one or the axial axis ( 27 ) wound layer layer ( 40 ) consisting of a plurality of ceramic layers firmly bonded together both by sintering and by sintering. 41 . 42 . 43 . 48 . 49 . 53 ), between which a plurality of fluid flow channels ( 51 ) for a fluid to be filtered ( 65 ) and multiple permeate fluid channels ( 52 ) for a fluid permeate ( 67 ) are formed, wherein the fluid flow channels ( 51 ) and the permeate fluid channels ( 52 ) in each case in a channel direction ( 26 ) in one or the axial direction ( 47 ) extend substantially parallel to each other, and wherein the ceramic layers ( 41 . 42 . 43 . 48 . 49 . 53 ) a ceramic permeate removal layer ( 43 ) for the removal of the permeate ( 67 ) and a porous separating layer ( 42 ; 48 . 49 ) for filtering the fluid to be filtered ( 65 ) comprising the fluid flow channels ( 51 ) from the permeate fluid channels ( 52 ) as well as another porous separating layer ( 41 ) or a ceramic barrier layer ( 41 ) located at a radial distance to the permeate transport layer ( 43 ), and wherein the fluid flow channels ( 51 ) and the permeate fluid channels ( 52 ) of the layer layer ( 40 ), viewed in the radial direction, between the further separating layer ( 41 ) and the permeate removal layer ( 43 ) or between the barrier layer ( 41 ) and the permeate removal layer ( 43 ) are arranged, and wherein the fluid flow channels ( 51 ) to in the axial direction ( 47 ) facing away from each other end faces ( 44 . 45 ) of the filter element ( 50 ) are open, and wherein both the permeate fluid channels ( 52 ) as well as the permeate removal layer ( 43 ) in the area of both end faces ( 44 . 45 ) of the filter element ( 50 ) are closed by a sintered ceramic material, and wherein the fluid flow channels ( 51 ) for the fluid to be filtered ( 65 ) on the one hand, in the radial direction to a first surface side of the filter element ( 50 ), of the further separating layer bounded by substantially flat surface parts ( 41 ) or barrier layer ( 41 ) limited in a winding circumferential direction over the spirally wound layer layer ( 40 ), and wherein the fluid flow channels ( 51 ) on the other hand, in an opposite direction to a side facing away from the first surface side second surface side of the filter element ( 50 ), of one or the stepped or wave-shaped channel wall of the separating layer ( 42 ), and wherein the permeate fluid channels ( 52 ) for the permeate ( 67 ) on the one hand, in the direction of the first surface side, of the step or wave-shaped channel wall of the separating layer ( 42 ) is limited, which in the winding circumferential direction over the spirally wound layer layer ( 40 ), and wherein the permeate fluid channels ( 52 ) on the other hand, towards the second surface side of a further, porous, ceramic layer or of the permeate-transport layer ( 43 ). Filter element according to claim 8, characterized in that the step or wave-shaped channel wall of the separating layer ( 42 ) on its the fluid flow channels ( 51 ) bounding inside with a ceramic membrane ( 48 ) whose mean membrane pore size is smaller than an average substrate pore size of a membrane ( 48 ) carrying substrate material ( 49 ) of the said channel wall. Filter element according to claim 8 or 9, characterized in that the fluid flow channels, viewed in an imaginary sectional plane perpendicular to the channel direction have a larger channel cross-section than the permeate fluid channels.

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