DE19540876A1 - Multi-layer separation units - Google Patents

Abstract

In order to solve different separation or filtration problems, the prior art discloses separation elements whose separation units have very different constructions, including separation elements with multi-layer separation units. The solution according to the invention is characterized in that the separation units (17) according to the invention can be produced in a continuous process and can be adapted optimally to specific separation problems by a layer-by-layer construction which also contains separating means (24) which are not in strip form.

Description

The invention relates to multi-layer separation units and separation elements made therefrom for treatment of liquid or gaseous media as well as a process for the production of multi-layer separation units.

Different separation or filtration problems Separation elements are to be solved in the prior art different construction and different Structure of the separation units known. Below are separation elements with multilayer Separation units.

Aim of a multilayer structure of the separation unit it is, on the one hand, a gradation in mechanical To generate deposition by the pore size in the Separation or filter unit from side to side e.g. B. increases or decreases continuously, on the other hand in certain regions of the separation or filter unit Zones with special adsorptive, absorptive, catalytic, ion exchange, chromatographic or chemically active or other specific properties be formed.

From DE 39 11 826 C2 z. B. known a filter candle, where the filter fleece wrapped around a central tube over its length is seamless in the winding direction  successive zones with continuously varied Has pore size and / or adsorption characteristics. The wound filter candle thus has a radial direction a filter unit with different Retention characteristics. By varying the Retention characteristics are possible in different filter properties to a filter unit unite. However, the manufacture is such The filter unit is expensive because a filter fleece is prepared in the longitudinal direction from his one to his other end is continuously or gradually changing Has filter properties. The change in Filter properties must be adjusted so that after the winding over the width of the filter fleece desired filter profile in the radial direction. It must not only be taken into account here that the Diameter of the resulting separation element through the layers continuously added during the winding process changes, but also that the diameter depends on it is the influence of superimposed winding layers, e.g. B. by compression, exercise on each other.

Especially if a filter candle is in the Filter unit layer by layer changing properties The required filter fleeces are to be built up prefabricated only with great effort. Because in this Homogeneous sections must be immediately in the case Production of the filter fleece in a web or through Pieces of multiple sections are always generated exactly one wrap circumference that fits with each layer changes, correspond. Does the diameter of the Central tube must have a differently constructed filter fleece be generated. Whenever the separation or Filter units of such candles from many different filter materials whose properties change layer by layer must work with piece of filter fleece  be so that for different diameters of Central tube and depending on the location of the individual winding exactly adhered to lengths Need to become. Continuous manufacturing Single strips are not economically possible. Will the Stripes glued or welded together, goes additionally a considerable part of the effective filter area lost.

For the economical production of from DE 39 11 826 C2 known filter candle with multi-layer separation or Filter unit is also problematic in that the width the width of the necessary filter fleece certainly. These must be made at least as wide or cut to this width. Especially at Candles made of different materials arise here often larger amounts of material waste because the Home fleeces on production machines with the different manufacturing widths are generated.

Even with pleated filter cartridges, the filter unit is in usually built up in multiple layers. The multilayer This includes drainage and protective layers produces multiple filter tracks of individual Unrolled and just before the Pleating knives are brought together. This sets in make sure that the individual layers are prepared, d. H. are cut to the same width, the other is the number of incoming and parallel Limited layers for spatial and handling reasons, because one unwind station is required. In addition takes with the number of incoming layers the risk of mutual course, so that usually shortly before the Pleating knives performed a leveling cut must be, which means an increased waste.  

Furthermore, you can only very much between two filter tracks difficult to add additional filter aids and the individual filter sheets must be so tensile that they let it roll without tearing. The latter is very thin Filter fleece, the z. B. are necessary to very fine Generating gradations in the pore size, usually not given.

DE 44 01 116 A1 describes a filter cartridge with a multilayer separation unit disclosed, in which the Separation unit is formed in that a Carrier mat is wrapped around a perforated support tube and one between the individual turns of the carrier mat Layer of powdered filter aid arranged is. Both the filter aid and the carrier mat are homogeneous in themselves. So it's not with every shift a specifically different separation effect or can be generated. If you want to do this for the carrier mat, so there are the same disadvantages as in the DE 39 11 826 C2 described filter candle. Do you want what often desired or necessary, various Introduce filter aids, so the winding process each be interrupted for a new device for to install the filter aid entry or the Exchange filter aids. It would be even more cumbersome on the fully spread out carrier mat section for Section the necessary filter aid and then the backing mat around the core wrap. This is not just a question of technology Difficulties due to the unfixed Filter aid, but it is also hardly to ensure that there is no gap in the shift same filter aid is located.

Generally, it turns out to be very difficult and elaborate, customized, multi-layered Separation units, with or without additional  Separation means, between two separa each tion medium webs, in a continuous process to manufacture. This is especially true if the Production of separation elements not at the same time the manufacture of the multi-layer separation unit takes place, but the multi-layer separation unit z. B. in the form of rolls or sheets, flat or Flat tube material, with a specific layer sequence as Starting material z. B. for pleating, punching or Winding processes is required. On the other hand, it always does also important for specific separation tasks rations units with a specific structure.

The task is based on this state of the art of the invention in multilayer separation units create very easy to manufacture variable to a specific separation problem by a customized layer structure can be adapted.

This task is solved by a multilayer Separation unit with the features according to claim 1. Advantageous refinements result from the Subclaims. A method of making the multilayer separation unit as well as advantageous Refinements of the method are in the Claims 19 to 31 specified.

The solution according to the invention is also characterized by that the invention, by a specific Layer by layer construction to a specific one Separation problems adaptable separation units in one have a simple process made. Through the helical winding of several Separation center webs of different nature, which in any quantity can be prefabricated, you get each individual separation layers, although can be multilayered, but are homogeneous in themselves. Between  these layers of separating center webs can be easily introduce other separating agents without the manufacturing process must be interrupted.

Waste is largely avoided because in the course of the Manufacturing process separation element blanks without Loss of desired length can be cut off or Flat sheets or flat tube sheets are lossless can be wound up. From pre-made Separation center webs of any width and type, leave Multilayer Separa according to the invention without any problems tion units in the desired diameter or desired Produce web width in tubular form or as web goods.

A filter element with a helical winding Needle felt material as separation unit is out G 91 11 139.1 known, but this is a Filter unit from only one layer, in which the Problem of adaptation to special filtration problems does not provide and that to solve such filtration or Separation problems are also not suitable.

In those known from EP 0 335 571 A1 and DE 39 11 826 Filter cartridges are made of a filter material cylindrical protective cover, which consists of a Tape material is made up along a helix the filter material is placed.

DE 44 03 652 A1 also describes a method for Manufacture of tubular membranes described, in which the tubular support on which the membrane layer is produced consists of two tubular layers that are offset wound helically to each other and to each other are welded.

Under multi-layer separation unit is in this Documentation by definition the sum of the Separation layers, including protective layers  (Protection during processing and during use in one Device) and drainage layers, understood, with separation units according to the invention, the Separation center webs or their edges at the Production of a tubular separation unit, are arranged like a screw wrap. When flattening or cutting open tubular separation units there is a diagonal position of the separation center webs to each other.

Is the manufacturing process of the separation unit with the Production of separation elements is coupled, so arise in the manufacturing process according to the invention in the Rule separation element blanks, d. H. Base units that alone or with several or with other base units combined to the final separation elements be further assembled.

Separation agents in the sense of the invention are in Common language use referred to as filter media. The term separation agent is preferred here used to underline that for its effect a flow is not absolutely necessary, but the Interaction even with simple media contact adsorptive, chemical, catalytic, capillary (suction) or other mechanisms can take place.

The separation means are based on their pore size or separation limit properties (coarse, fine, micro, Ultrafiltration and Reverse Osmosis), their separation mechanism (Sieve, depth filtration, adsorptive filtration, Pervaporation, vapor permeation, gas separation. . ) and yours Interaction with the medium to be treated (specific and non-specific adsorption, chromatography, catalysis, Ion exchange, capillary action, electrical action. . ) characterized. The separation means can both as a barrier as well as adsorber and reaction surface or  Reaction volume for certain ingredients of Gas mixtures, aerosols, liquid mixtures, solutions as well as colloidal and particulate suspensions.

Thread-like, ribbon-like, flat or flat tubular and hollow fiber, surface-active and or porous substances in question, to which in or between which z. B. adsorptive, catalytic, biocatalytic, via a zeta potential or through Substances with an electret character or for ion exchange capable functional groups or media bound, fixed or can be stored as well as fibrous, powdery, granular or other bulk goods Substances with a separation effect.

Each individual layer becomes a separation layer here Separation means understood. A special kind of Layer represent layers of wrapable, flat or flat tube-shaped separation means. These are referred to here as separation center webs.

Flat separation center webs can e.g. B. plastic or Wire mesh, extruded or otherwise manufactured Grids, fleeces, papers, membranes or foils. Examples are glass fiber papers, cellulose papers, papers with embedded activated carbon or kieselguhr particles, wet or dry laid nonwovens, needle felts, needled nonwovens, Carded fleece, carbon fiber fleece, spunbond fleece, Meltblown fleece, split fiber fleece, flash spun fleece, Hot melt adhesive fleeces, perforated or embossed foils or Membranes for micro and ultrafiltration, for Reverse osmosis and pervaporation.

The separation center webs can be used in many different ways be pretreated. Examples of such treatments are Calendering, creasing, surface modifications,  Coatings, impregnations, flames, corona and Plasma treatments, roughening, carbonization, etc. Fibrous, powdery, granular or other bulk goods Separation means must be fixed, but also without Fixation can form a separation layer. Examples of such bulk separation agents are ion exchange media, activated carbon media, Adsorber resins, water absorbing fibers, granular Catalysts, molecular sieves, chromatography media, Dry media, materials with defined zeta potential, Flocculation media, bactericidal substances, bacteria, yeast, bioactive substances, electrically conductive substances, about Magnetism or electric fields, etc.

In the following the invention based on Embodiments and process examples below Described with reference to the accompanying drawings in which shows:

Takes place in the Fig. 1 is a schematic representation of a production line, the production according to the invention separation units without additional support core,

Fig at takes place. 2 is a schematic representation of a production line, the production according to the invention separation units with an additional support core,

Fig. 3A is a perspective view of a separation element of the invention with an inventive separation unit,

Fig. 3B shows a longitudinal section through a separation unit,

Fig. 3C is a cross-sectional view of a separation unit according to the invention,

Nierungsstufen Fig. 4A and 4B are perspective views of the invention Separation elements according to the invention with separation units in various Konfektio,

Fig. 5A is a perspective view of a separation element of the invention are bundled in the separation element blanks of the invention separation units,

FIG. 5B to 5D are cross sections through further bundling arrangements for separation element blanks,

Fig. 6A, a separation element according to Fig. 5A in which a front face of the separation element blanks were welded separately,

Fig. 6B is a schematic representation of how the welding and the cutting of separation element blanks may be linked to each other,

Fig. 6C and 6D are perspective views of two further separation elements in which separation element blanks are bundled

Fig. 7A shows a cross section through a separation unit according to Example 2,

FIG. 7B is a cross section through a separation unit according to Example 4,

Fig. 7C is a cross section through a separation unit according to Example 7 and

Fig. 8 is a longitudinal section through a separation unit according to Example 6.

That for the production of the invention Separation units used winding process preferably carried out in such a way that for all flat Separation center webs the winding direction is the same because can be manufactured continuously. It is natural but also possible for single or multiple layers Separation center webs to reverse the winding direction. This is z. B. desired to the stability of the winding increase or arrange certain layers of drainage so that there are structures with a lower filter resistance surrender.

In principle, known methods can be used for the winding process Spiral sleeve winding machines, such as those used for. B. at the Manufacture of toilet paper cores or core sleeves for the paper and film industry are used, can be used if these for the invention Procedures are modified accordingly.

Such a modification is e.g. B. working with a or more pressure or pressure rollers that the Solidify windings. The pressure rollers can be driven. Such pressure rollers are e.g. B. necessary when very fluffy separating agents are compressed should or if the inherent strength of a flat Separation center web is insufficient to provide the necessary To generate strength of the winding over the winding pull.  

The flat separation center webs can be made from the different materials exist and can have any width. With expensive materials, such as Membranes, even narrow margins come out, which are normal incurred as waste, as wrapping material in question. The Separation center webs are made from a supply roll unrolled and free at a defined point under one selectable angle on the mandrel or at this point already generated winding attached. The desired Sequence on two-dimensional separation center webs achieved in that the supply rolls in the predetermined Order hung in a supply gate and from there the running tracks one after the other and one above the other a winding mandrel can be wound up.

Should several layers be in and in the separation unit the same flat separation center web one above the other come, so these can be successively from different supply rolls and then screw spiral be wound up or supply rolls are produced, where the desired number of layers already is wound on top of each other. The latter is preferred if very many thin layers of the same quality stacked on top of each other should be wrapped.

On the other hand, the insertion angle of Degree of overlap n for a single separation center web depending on the web width, the thickness of the web and the diameter of the mandrel or winding core as desired to get voted. A degree of overlap n of 1 corresponds a flush winding, a degree of overlap less than 1 means that the winding tracks are at a distance, a Degree of overlap n greater than 1 indicates how many layers same separation medium layer with a cross section by the layer formed by this separating agent layer The winding cylinders lie one above the other. n means 7.5 then z. B. that in cross section 6 layers with full extent  are recognizable and the innermost and outermost position together have 1.5 times the length of a circumference. The mathematical relationships for a cylindrical Separation unit represents the following formula:

n = B / 2 _* π _* D _* cosβ + (RD) ² / 4 _* D² - (RD) / 2 _* D

N is the degree of overlap, B is the web width Separationsmittelbahn, D the thickness of the Separation center path, R the radius of the core or the Axis on or on which is wound up and β the Angle between the separation center web and the winding core or Winding axis.

Thread-like, band-like, hollow fiber-like Separation means or other separation means that are coherent or unwindable, are like that Separation center webs as single or multiple layers in introduced the wrap.

Above every incoming, flat separation center web can, e.g. B. shortly before the place of winding up, Devices are installed with which, for. B. particulate, fibrous or sprayable separating agents and other auxiliaries can be introduced between two layers each of two-dimensional separating center webs form an additional separating agent layer. over these devices can e.g. B. also glue, Impregnations, wetting agents, granular spacers, Dyes etc. at the desired location in the Insert separation element. They can also Separation center webs before winding z. B. for Wetting, impregnation or coating by immersion baths or application roller systems etc. are performed.  

As described above, adjacent edges can be one flat separation center web overlapping (n <0), flush (n = 0) or at a distance (n <0) to each other.

Overlapping separation center webs can be through Additional devices in the overlap zones with each other glue, weld or otherwise leakproof connect with each other. The abutting edges If necessary, flush separating center webs can pass through suitable adhesives (e.g. silicone or hot melt caterpillars) or welded together tightly.

If the winding overlaps, the overlap zones become the individual separation center webs preferably arranged so that a winding tube with as even as possible Diameter is generated.

The winding mandrel is preferably cylindrical or conical (truncated cone), but can also be another, e.g. B. in Cross-section have polygonal or elliptical structure.

The multi-layer separation unit can be on one Support core, as well as without a support core on the winding mandrel be generated. The core diameter or diameter of the The mandrel can be freely selected based on the process.

If the separation unit is generated on the support core, so is usually with the manufacture of the separation unit at the same time the production of separation element blanks coupled.

To mechanically stable separation element blanks without Support core or corresponding separation units can create one or more more stable layers, e.g. B. from tissue or mesh, during the Winding process at the desired location or zone can be integrated as layers in the separation unit.  

For types with a support core, this can be done in shorter pieces running along the winding axis from welded or otherwise supplied with interconnected base cores be, the individual pieces about complementary Interlocking knurls or recesses or welded together using an additional device (e.g. Rotational welding).

Another variant is to also pass through the support core to generate the winding process itself using a spiral screw. Are very thick, inflexible for stability reasons Plastic grid necessary, so the entire supply roll or the developed path with appropriate facilities be warmed before curving. At tubular separation units with very small The core can have an inner radius thanks to more flexible mesh grids are generated, the z. B. the structure of the process or the removal of the filtrate in the axial direction itself then allowed if the nucleus formed is a very small one Has inside opening.

The number and type of separation medium layers one separation unit according to the invention can be individually adapt to the respective separation task.

The multilayer formed by the winding process Separation units or separation element blanks can be cut to the desired length without the manufacturing process must be interrupted. It is the same possible a cylindrical, multilayered Separation unit after the last processing station flatten and as a flat hose for the Further processing or the multilayer, cut open cylindrical separation unit and so obtained multilayer, web-shaped separation unit for further processing.  

Above the individual separated center webs or any regions of the screw wrap formed devices can still be installed with them the separation properties or the Process engineering properties can be changed. By heating z. B. with IR rays or blowing in hot air can be used with hot melt adhesive fleeces or fibers Core-shell characteristics activated and thereby the Structure of the separation element by connecting individual ones Layers or fixation of particulate separating agents be stabilized. About corona lines z. B. electric charges in fine-fiber fleece from meltblown bring this a permanent electret character to lend. By UV radiation z. B. sprayed in hydrophilizing, hydrophobic, oleo Activate phobizing and the like substances so that the Surface of the sprayed separation medium permanent is modified. By touching an ultrasonic horn it is still possible to use certain flat areas Separation center webs to compact or particulate Better to distribute substances in their matrix. Other Devices allow e.g. B. the thermal solidification of Outer layers by using several layers in a line are welded to each other.

Many of these treatments can also be scheduled in advance Carry out roll material. But this usually means one additional work step. Second, it is common Treatments are advantageous shortly before or shortly after perform the wrapping to e.g. B. storage-related Avoid changes or the winding curvature to use adapted states.

In Fig. 1, a production line for the separation units according to the invention is shown schematically. The separating center webs ( 3 ) to ( 10 ) can be fed from the supply rolls (not shown) to the winding mandrel ( 2 ) or the spiral winding ( 16 ) which forms the separation unit. For reasons of clarity, the separating center webs ( 3 ) to ( 10 ) do not overlap. In principle, however, this is possible. It is shown that the separation center webs ( 3 ) to ( 10 ) can have different widths. It is not absolutely necessary that all separation medium webs run in. Of course, production lines can also be implemented with significantly more incoming separating center webs. Furthermore, it is not shown that the separating center webs or the associated supply rolls can be braked. If no strong pull is to be exerted on a separation center web, the supply rolls can also be driven for processing.

The conical winding mandrel ( 2 ) is driven by the motor ( 1 ) in the specified direction of rotation. At the start of production, the separating agent layer ( 3 ) is first wrapped around the winding mandrel ( 2 ) and advanced approximately to the separating agent layer ( 7 ). The separation medium web ( 4 ) is then wound onto this first layer ( 3 ) and driven at least to the extent that in the next step the full width of the separation medium web ( 6 ) can be wound onto it. In an analogous manner, the spiral wrap or the separation unit ( 16 ) is built up layer by layer and the winder is advanced with all the separation medium webs ( 3 ) to ( 10 ) to such an extent that it projects beyond the pressure rollers ( 14 , 14 ').

Next, if they are required for a separation unit type or separation element blank type, the metering devices ( 12 , 12 ', 12 '') are brought into position and activated. The same applies to the welding station ( 11 ) with which the edges of the separating central web ( 5 ) are welded to one another in a leak-tight manner and to the welding station ( 11 ') which welds the edges of the separating central web ( 10 ) and the underlying separating central web ( 9 ) to one another. This welding with a lower layer serves in some separation element blanks ( 17 ) for the external hardening of the spiral wrap ( 16 ) or the separation unit, ie the stability with respect to e.g. B. pressure surges from the core to the outer radius, as they often occur in practical use. This so-called external consolidation takes place after the station with the pressure rollers ( 14 , 14 '), because then the position of the screw winding layers to each other is final. If this external hardening is not sufficient, the separation element blank ( 17 ) can also be provided with outer protective members or protective cages. Of course, pressure rollers and welding stations of various types can also be installed at other points on a production line. The same applies to heating devices ( 13 , 13 ) z. B. work with hot air or IR radiation or the corona path ( 15 ) with which in Fig. 1 the separation center web ( 9 ) an electrical effect can be impressed.

In FIG. 2 is a variant of a production line can be wound about each other at which only three separation means tracks (3) to (5). Furthermore, the separation center web ( 3 ) is not on a winding mandrel ( 2 ) but on a prefabricated support core ( 21 ) z. B. wound from a thermoplastic such as polypropylene. This core is driven by the motor ( 1 ) in the specified direction of rotation. The winding structure is carried out in an analogous manner to that described in FIG. 1. So that the production does not have to be interrupted permanently, the rotating core ( 21 ) is automatically extended by a basic core ( 21 ') at certain intervals. The denomination is carried out, for example, by means of a friction welding unit ( 22 ), the end faces ( 20 , 20 ') being melted for a short time by stronger rotation of the base core ( 21 ') upon contact and then connecting to one another in a leak-tight manner. So that the frictional forces are not too large, the end faces ( 20 , 20 ') z. B. designed according to the tongue and groove principle.

A spray station ( 18 ) is shown as a further variant in the production line according to FIG. 2. This allows z. B. Separation agents or modification media, which are present as a dispersion or solution, as a separation layer in the winding. For example, it could be a bacterial suspension if a separation element is to work with a separation unit ( 16 ) according to the invention as a membrane reactor. With the spray station ( 18 ) z. B. also spray dispersion glue or it is a hot melt spray station, the sprayed hot melt beads ( 23 ) z. B. can be activated by the heating device ( 13 ) when the affected winding layers have assumed their final shape. The dosing station ( 12 ) applies a further separating agent layer ( 24 ) to the separating agent sheet ( 4 ). This comes into direct contact with the still adhesive hot-melt beads ( 23 ), so that the separating means ( 24 ) is fixed in a certain way. By activating the hot melt caterpillars at the heating station ( 13 ) this fixing process is intensified again.

In Fig. 2, a cutting device ( 19 ) is also outlined, with which the blanks ( 17 ) for z. B. a separation element ( 25 ) from the finished spiral winding or separation unit ( 16 ) can be cut off. This cutting can be carried out without interrupting production because the cutting device can follow the forward movement of the tubular separation unit ( 16 ).

Fig. 3A shows a perspective view of a cut to length by a separation unit according to the invention the blank.

Fig. 3B shows the corresponding separation unit ( 16 ) in longitudinal section, Fig. 3C in cross section.

In Fig. 4A is a variant of a, ready konvektionierten separation element (25) is shown in perspective with an inventive separation unit (16), ie to the winding end (26), a closed end cap (28) welded while the front end (27) with a so-called Housing adapter ( 29 ) was provided. Before welding onto the plastic parts ( 28 , 29 ), in many cases the end faces ( 26 , 27 ) of the blank ( 17 ) are sealed, if necessary using additional molten polymer, or the end faces ( 26 , 27 ) formed into open end caps ( 30 , 30 '). This is shown in Fig. 4B.

If separation element blanks ( 17 ) with a very small diameter are produced, they are not individually convectioned as shown in FIG. 4A, but several of these blanks are bundled and combined to form a separation element. A perspective view of such a separation element (31) from individual blanks, FIG. 5A.

In FIG. 5A, seven separation element blanks (17) are bundled cylindrical. The end faces ( 27 ) are cast into a closed end cap ( 28 ). The end faces ( 26 ) can be provided with a special adapter ( 29 ), which collects the filtrates of the individual blanks ( 17 ) that each emerge from the end faces ( 26 ), but seals the bundle of blanks against the unfiltrate side. Other exemplary cross sections through bundle arrangements are shown in FIGS. 5B to 5C. Bundling always tries to produce the densest packs, or configurations which, when several separation elements ( 31 ) are operated in parallel in a common housing, result in as little dead volume as possible between the separation elements. An advantage of the bundle configuration is that the number of seals required is minimized via the common drain adapter. Which bundling configuration is selected depends on e.g. B. from what diameter the separation element blanks ( 17 ) and what total diameter is allowed for a separation element ( 31 ).

A special variant of the seal of separation elements (31) are presented in Fig. 6A. The end faces ( 26 ) are cast into an adapter ( 29 ), while the end faces ( 27 ) are each welded together. This welding can element blanks ( 17 ) with a small diameter before cutting to length, z. B. done by ultrasound. The cut is made directly behind the weld seam, so that blanks ( 17 ) with an open forehead ( 26 ) and a closed forehead ( 27 ) are cut to length ( FIG. 6B), which can then be further processed into the separation element ( 31 ).

A further bundling variant for separation element blanks ( 17 ) is shown in FIG. 6C. The blanks ( 17 ) are in contact or at a short distance from each other in one plane and form a comb-like after the sealing (except for the drainage channels), or if both sides of the blanks ( 17 ) are cast in a cassette-like separation element ( 33 ). Several such blank layers can lie on top of each other. Is the potting or sealing compound ( 34 ) made of flexible material, such as. B. polyurethane, then such a separation element ( 33 ) as shown in Fig. 6D can also be operated in curved housings.

In principle, by bundling of the invention separation element blanks (17) a wide variety of element configurations produce, so that separation element blanks according to the invention (17) can be installed to corresponding bundling and adaptation in a large part of the market today housing and operated.

The separation units ( 16 ) according to the invention can also be obtained as web goods by z. B. the formed separation unit according to the invention ( 16 ) is cut at the angle necessary for a degree of overlap n = 1 and the web being formed is wound up. The core diameter is decisive for the resulting web width. This is preferably chosen to be very large. This minimizes the offset problems caused by the curvature. Another variant in this regard is to wind on a relatively flat, elliptical mandrel rather than on a cylindrical cross-section. The ge flat hose formed, can then be cut open at the edges so that there are two separation unit webs ( 16 ).

If you want to wind up separation units according to the invention ( 16 ) as a flat tube, the winding device must rotate in the same way as the spiral wrap ( 16 ) itself. If only tube pieces of a certain length are required, they can be used in a similar manner to separation element blanks ( 17 ) without interruption of the production process.

The web-shaped, inventive separation units ( 16 ) can, for. B. a pleating process. It is also conceivable that they are in turn wound up into a conventional spiral wrap. Other forms of assembly are rectangular or differently assembled filter mats, filter bags or round filter die cuts.

A significant advantage of the separation units ( 16 ) according to the invention is also that the relatively thick layers that are often necessary for adsorptive separation can be produced without difficulty and that they are obtained in cylindrical form as separation element blanks ( 17 ) by the method according to the invention, which are produced without additional processing of the actual separation unit ( 16 ) can be further assembled. In contrast, z. B. the assembly of thick flat separation units using pleating technology only possible up to a certain thickness.

Using examples of the layer structure of multilayer separation units ( 16 ) or separation element blanks ( 17 ) and separation elements ( 25 , 31 , 33 ) produced therefrom, it should be exemplified which improvement potential is provided by the separation units according to the invention and which range of applications can be developed with them can.

The comments can be made on many separation problems transferred in various industries.

example 1 Clarifying filter elements with "onion function"

For clarification filtration of cloudy liquids, the turbidity of which is caused by dispersed particles or fibers, a pure surface filtration is usually sufficient for clarification. Suitable filter media are, for. B. meltblown nonwovens with a pore size (according to Coulter) of about 20 microns. Such meltblown nonwovens can be produced with a tensile strength of 20 g / m². In a separation unit ( 16 ) according to the invention, approximately 30 of these layers are wound one on top of the other. The adjacent edges of a filter belt ( 3 ) overlap by approx. 0.5 cm. The overlaps are not welded together. It is wound around a core with a diameter of approx. 65 mm. The total diameter is approx. 70 mm. The high number of identical filter layers lying on top of each other results in an initial filter resistance, which allows the optimal construction of a filter cake. The surface of such filter units can be freed of the filter cake several times by backwashing. If this is no longer possible from sufficient, the outermost blocked filter layer is separated or peeled off, which is possible without difficulty with this separation unit according to the invention. If the effect is not sufficient, one or more additional layers are removed. In this way it is possible to use a separation element several times with the same separation quality.

In principle, the separation units ( 16 ) according to the invention, which are built up layer by layer, allow these layers to be broken down layer by layer again, unless layers were welded or glued to one another in the course of production. This aspect is also of great interest with regard to recycling or the regeneration of used or exhausted separation elements or separation means.

Example 2 Pollen and odor filters for motor vehicles

Modern motor vehicles are now using filter systems equipped, which the outside air, which in the Passenger cabin arrives from pollen and bad smells clean. As a particle filter come here, for. B. Meltblown nonwovens with electret properties are used. Activated carbon or specific, synthetic adsorber resins used. With the usual Processing in pleating machines result in Presence of activated carbon or adsorber resin layers often difficulties, as it is mainly in the Pleating edges come to damage. Additionally prepares  the immobilization of the activated carbon or adsorber resins technical difficulties and is therefore very expensive.

The following describes how, according to the present invention, the separation unit ( 16 ) of a suitable separation element of the type mentioned above is constructed and how it can be produced. A cross section through a corresponding separation unit (16) is shown in FIG. 7A. Starting from FIG. 1, the core of the separation element blank ( 17 ) is formed in line with the separating agent layers ( 3 ) and ( 4 ) made of open, coarse mesh grids on the approximately 5 mm thick winding mandrel ( 2 ). The separation center web ( 6 ) is first wound onto this "core", this is a thin spunbond or meltblown fleece with pores that are smaller than those of the particles that are to be introduced as adsorbers. These nonwovens also have a higher melting point than the next separation center web ( 7 ). Furthermore, the edges of the web ( 6 ) are welded to one another in a leak-tight manner at the welding station ( 11 ). The separating medium web ( 7 ) is a thin hot-melt adhesive fleece onto which a homogeneous layer ( 24 ) of adsorber particles is applied at the metering station ( 12 ). The hot-melt adhesive fleece ( 7 ) is activated by means of the heating station ( 13 ) in such a way that the adsorber particles largely adhere to this fleece. If only one layer of adsorber particles ( 24 ) is required, the stations ( 12 ', 12 '', 13 ', 13 '') remain out of operation and the webs ( 8 ) and ( 9 ) do not run in. If two or three adsorbent layers are required, the processes are repeated as for the web ( 7 ). Before the meltblown fleece ( 10 ), which takes over the function of the particle filter, is wound up as the next layer, it is electrically charged again in a corona section so that it acquires a permanent electret character. The edges of the separation center web ( 10 ) are welded together at the station ( 11 ') in a leak-tight manner. The separation center web ( 5 ) made of an open spunbond fleece serves as an outer protective layer. This is solidified at the station ( 11 '') by welding.

When only one adsorber particle layer ( 24 ) is wrapped, the diameter of the separation element blank ( 17 ) or the cylindrical-shaped separation unit ( 16 ) is approximately 15 mm. With a length of 250 mm, the surface is then approx. 117 cm². If one bundles 7 such units according to FIG. 5A, the total surface area is 824 cm 2, with a diameter of 45 mm for the separation element ( 31 ). When bundling according to FIG. 5D, 19 units result in an area of 0.22 m 2 with a diameter of 75 mm. With a two-layer arrangement according to FIG. 6C, a filter surface of 0.375 m 2 would result for a separation element ( 33 ) with the dimensions 250 _* 250 _* 35 mm³.

If there is no odor, you can in the operate filter without odor remover in the same housing. Conversely, odor filters are also without additional ones Particle filter conceivable.

See also example 4.

Example 3 Filter element for descaling small amounts of water

If water is heated above 65 ° C, depending on the degree of hardness, scale or calcium carbonate will precipitate. This so-called temporary hardness of the water not only leads to limescale deposits, but also influences e.g. B. also the taste of hot drinks such as tea etc. One method of softening water is the treatment with cation exchangers. This is e.g. B. in each dishwasher prior art. Here, however, the water is usually first softened and then heated. For various other applications, however, it seems to make more economic sense to first separate the lime deposits that form from the heated water using a relatively coarse filter and only to remove the residual hardness using an ion exchanger. A separation unit ( 16 ) or a separation element blank ( 17 ) according to the invention corresponds to that of Example 2, but a cation exchanger is introduced as a particulate layer ( 24 ) and the meltblown layer ( 10 ) has a pore size (according to Coulter) of around 40 μm. Such a filter element has z. B. proven in a system in which the water for the windshield wiper washer of a motor vehicle is heated by heat exchange via the cooling circuit. Since temperatures above 65 ° C are clearly reached, the spray nozzles were always blocked by limescale. With the separation element that contained the separation unit ( 16 ) according to the invention and which was installed after the heat exchanger spiral, the windscreen wiper nozzles were no longer blocked.

See also example 4.

Example 4 Separation units with differently acting separation agents

A common method for clarifying liquids such as beer, wine and other biotechnologically produced media is e.g. B. treatment with diatomaceous earth. In analogy to Example 2 or 3, separation units ( 16 ) can be realized which have several particulate separation layers, e.g. B. in the form of differently fine diatomaceous earths. FIG. 7B shows a cross section through such a cylindrical separation unit (16). The support core ( 21 ) is covered by a spunbond fleece ( 3 ) that acts as a support fleece. The separation center web ( 4 ) is a calendered meltblown fleece that also holds yeast absolutely. The separating center web ( 7 ) is a spunbond fleece on which a relatively thick, coarse mesh grid ( 6 ) lies. These two layers were previously rolled up on a roll. A layer of fine Gur ( 24 ) is applied to this double layer by means of a dosing station, the Gur filling the cavities of the coarse grid ( 6 ). There follows a further double layer of a spunbond fleece ( 7 ') and a coarse grid ( 6 ') onto which a coarse belt ( 24 ') is applied. The outermost layer ( 5 ) in turn forms a spunbond fleece or a coarse meltblown fleece.

In an analogous manner, instead of the fine belt ( 24 ), e.g. B. PVPP for protein stabilization can be introduced as a separating agent or a PVPP layer is first formed in the manufacture of the separation unit ( 16 ) and only then the stepped diatomaceous earth layers.

For other applications z. B. the alternating installation of an anionic and cationic ion exchanger (deionization of water) or a combination of desiccants with catalysts (detoxification and drying of air). It is also conceivable that different microorganisms are immobilized in the individual intermediate layers, the z. B. can cause a denitrification of appropriately contaminated water. For the treatment of colloid-contaminated liquids or liquids that are to be de-pyrogenized, it is possible in an analogous manner to install separating agents or separating agent sheets with positive and or negative zeta potential in a separating unit ( 16 ) according to the invention.

Example 5 Filter elements with a separation unit, which is a very fine gradation in the degree of separation from the outer circumference to the support core

State of the art are e.g. B. filter candles with a diameter of approx. 62 mm and a thickness of the separation unit ( 16 ) of approx. 12 mm. The separation unit ( 16 ) consists of approx. 60-80 layers of prefabricated meltblown nonwovens with mass per unit area between 30 and 50 g / m². In order to achieve a staged filtration, ie to filter from coarse to fine, nonwovens with different degrees of separation are pieced together in such filter elements and wound up in a spiral. For economic reasons, the gradation is usually limited to five filter media per filter element type, since a denomination is required every 1.5 to 2 running meters. If you wanted to achieve a layer-by-layer gradation, you would have to chop the core every 13 cm, but at best every 20 cm. A total of about 60 to 80 pieces would have to be cut per candle. For the separation units ( 16 ) according to the invention, it is possible to achieve a gradation layer by layer in a continuous production process. If one starts from supply rolls, in which eight layers have already been rolled over one another in the correct gradation, and if one ensures that the entry angle permits an edge-closing winding, then this can be achieved with eight to ten supply rolls according to the inventive method. But it is also possible to work with very narrow supply rolls with little overlap. With a width of z. B. 100 mm then require 80 different supply rolls, which allow gradation over 80 steps, a width of the supply gate of only about 10 m.

Example 6 Separation units with bypass paths from Layer to layer

In the case of wound filter cartridges which are produced by simply winding spiral separating webs onto one another (compare Example 5), it is a disadvantage for some applications that the filter element must be discarded if only one layer of the separation unit is blocked. A separation unit ( 16 ) according to the invention remedies this disadvantage in that all or individual separating medium webs made of e.g. B. consist of two layers, one of these layers is so coarse that a lateral passage of the fluid to be treated is possible. If such double layers are wound overlapping according to the invention, there is the possibility of transverse bypass at each overlap point if a differential pressure that is greater than that for the bypass path occurs over a separation surface. The basic conditions are Fig. 8 schematically. A single-layer inner separating agent sheet ( 3 ) and also single-layer outer separating agent sheet ( 5 ) are shown. Since there are the double layers ( 4 ), ( 6 ) and ( 7 ) with the transverse drainage ( 4 ''), ( 6 '') and ( 7 ''). If all layers are unloaded, the medium to be treated flows primarily in analogy to line ( 35 ). If the blocking of the separation medium layer ( 7 ') increases, part of the unfiltrate will follow analogous paths such as the bypass path ( 36 ). Also blocks the separation center path ( 6 '), so paths like the bypass path ( 37 ) are becoming more and more likely.

Example 7 Separation unit with immobilized yeast

For the bottle fermentation of sparkling wine, it is a goal today not to simply put the yeast, which causes the second fermentation, into the bottle, since after it has died off, it is cumbersome to collect it by shaking it at the neck of the bottle and then freezing it as a plug must be removed. The yeast is immobilized in a separation unit ( 16 ) according to the invention or a separation element blank ( 17 ). The end faces ( 26 , 27 ) of the separation element blank ( 17 ) are welded leak-tight as in Fig. 4B. The cross section of the separation unit ( 16 ) is shown in Fig. 7C. A stable grid ( 3 ) forms the inner core. A hydrophobic membrane ( 4 ), e.g. B. made of PTFE or PVDF with a pore size of 1 µm or smaller, the side edges are glued or welded together. This membrane ( 4 ) is protected by a spunbond layer ( 6 ). Next, a double layer ( 7 , 8 ) of a spunbond fleece ( 8 ) and a coarse grid ( 7 ) lying thereon is wound, the drying yeast ( 22 ) required for the second fermentation being used as a separating agent in the cavities of the grid ( 7 ) is introduced. The outer layer ( 5 ) is a hydrophilic membrane with a pore size of 1 µm or smaller. Here, too, the side edges are tightly connected. For the second fermentation, such a separation unit ( 8 ), in which the end faces ( 26 , 27 ) are closed, as in FIG . B. connected to a spacer and inserted through the bottle neck into the sparkling wine bottle prepared for the second fermentation. The construction of the spacer ensures that this separation element is fixed in the bottle regardless of its position and that after the nine-month bottle fermentation has ended, after the crown cap has been removed, the separation element including dead yeast can be easily removed. During the fermentation process, all of the fermentable substances flow through the hydrophilic membrane ( 5 ) at some point due to differences in concentration or movements of the bottle. The metabolic product alcohol gets back into the bottle compartment through the hydrophilic membrane ( 5 ), while the metabolic product carbon dioxide enters the bottle compartment via the hydrophobic membrane ( 4 ). The yeasts are too large to pass through the membranes and remain in the separation unit ( 16 ) even after they have died. Finally, the grid ( 7 ) ensures that the yeasts remain evenly distributed over the surfaces of the membrane filters ( 5 ) and ( 4 ) and have favorable growth conditions.

Example 8 Asymmetrical separation unit Meltblown fleeces

It is for pleated filter cartridges for fine filtration e.g. B. usual several meltblown nonwovens on top of each other pleated to filter units with an asymmetrical To produce pore character. Limiting for the generation is such asymmetrical separation units the number of possible unwind stations, on the other hand the thickness of the resulting from many individual layers formed filter unit, taking into account that for stability reasons one for the pleating process suitable filter layer usually at least 15 g / m² Basis weight. Filter layers according to the invention allow a layer by layer gradation with layers which only have a mass of up to 2 g / m².

After producing a cross-sectionally elliptical separation unit ( 16 ) with the desired multilayer asymmetry, the separation agent tube ( 16 ) is z. B. first wound as a flat tube and this is then cut into webs or it is cut in line and the web material formed is immediately wound up. Possibly. can before further processing, e.g. B. by pleating, a calendering step to produce an even finer, asymmetrical pore structure.

Claims (31)

1. Multi-layer separation unit for the separation of liquid or gaseous media from at least two separating medium webs, each of which can be unwound from a supply roll, characterized in that each separating medium web ( 3-10 ) by a helical arrangement with a degree of overlap (n) of at least 1, that is, a flush or overlapping arrangement of adjoining side edges of a separating center web, forming an individual, homogeneous separating agent layer. 2. Separation unit according to claim 1, characterized in that the adjacent or overlapping side edges of the separating center webs ( 3-10 ) of the individual layers have the same running direction. 3. Separation unit according to claim 1 or 2, characterized characterized in that at least one of the helical arranged separation center web layers, by a degree of overlap (n) greater than 1 Side edges of the separation center web, more than is single layer.   4. Separation unit according to one of claims 1 to 3, characterized in that this by gluing or Welding of overlapping side edges, at least one separation center web, at least one Contains separation layer that does not bypass for a medium to be separated allowed. 5. Separation unit according to one of claims 1 to 3, characterized in that they additionally at least a layer of non-sheet separation means or web-shaped separation means with itself touching side edges, i.e. with a Degree of overlap (s) less than 1, which contains the Separation supported. 6. Separation unit according to one of claims 1 to 5, characterized in that the separation unit is tubular. 7. Separation unit according to claim 6, characterized characterized in that the hose is cylindrical. 8. Separation unit according to claim 6 or 7, characterized in that the inside of the separation unit hose is adjacent to a support core ( 21 ). 9. Separation unit according to claim 8, characterized in that the support core ( 21 ) is also formed by helically winding a sheet-like layer. 10. Separation unit according to one of claims 1 to 5, characterized in that the separation unit Flat material is made by cutting open a Separation unit hose is generated. 11. Separation unit according to claim 10, characterized characterized in that the flat material is treated becomes. 12. Separation unit according to claim 11, characterized characterized that the aftertreatment a Calendering process. 13. Separation unit according to one of claims 1 to 12, characterized in that the separation unit contains separable layers that can be activated. 14. Separation unit according to claim 13, characterized characterized in that the activatable Separation layers have adhesive properties. 15. Separation unit according to one of claims 1 to 14, characterized in that the separation unit Contains separation layers that are used to stiffen the Serve separation unit.   16. Separation unit according to one of claims 4 to 15, characterized in that at least one Separation layer contains microorganisms. 17. Separation elements, characterized in that they Separation units according to claim 1 to 16 included. 18. Separation elements according to claim 17, characterized characterized in that it consists of more than one cylindrical Separation element blank exist. 19. Method of making a multilayer Separation unit in the at least two prefabricated Separation center webs of one supply roll each be handled and successively over one Winding mandrel can be wound helically. 20. The method according to claim 19, characterized in that the helical winding for both Separation center webs at the same time Direction of winding takes place. 21. The method according to claim 19 or 20, characterized characterized that not web-shaped and not unrollable separation means on at least one incoming separation center web for formation additional layers of separating agent Separation unit can be applied. 22. The method according to any one of claims 19 to 21, characterized characterized in that with the help of one or more  one or more incoming Separation center tracks of arranged devices the entry into the screw winding a web treatment or web coating. 23. The method according to any one of claims 19 to 22, characterized characterized in that with the help of one or more suitable places of the forming or formed tubular separation unit installed Devices post-treatment of the screw wrap he follows. 24. The method according to claim 23, characterized in that with the help of an aftertreatment device Welding overlapping side edges of one Separation center path takes place. 25. The method according to claim 23, characterized in that at least one aftertreatment device is a pressure roller ( 14 , 14 ') for winding consolidation. 26. The method according to any one of claims 19 to 25, characterized in that the formation of the separation unit takes place on a support core ( 21 ) as a winding mandrel, which remains with the separation unit. 27. The method according to claim 26, characterized in that the support core ( 21 ) remaining in the separation unit is produced by attaching prefabricated core segments ( 21 , 21 '). 28. The method according to claim 26, characterized in that the support core ( 21 ) remaining in the separation unit is produced from one or more suitable prefabricated separating center webs as a screw spiral. 29. The method according to any one of claims 19 to 26, characterized characterized in that the tubular formed Separation unit is wound up as a flat tube. 30. The method according to claim 19 to 26, characterized characterized in that the tubular formed Separation unit behind a corresponding one Cutting device is wound up as a flat web. 31. The method according to claim 19 to 28, characterized characterized in that the tubular formed Separation unit as a segment Separation element blank is cut to length.