WO2013120753A1 - Filter component and production of the filter component with hydrophobic and hydrophilic regions for colloidal separation - Google Patents

Description

[Designation of the invention prepared by ISA according to Rule 37.2]
FILTER COMPONENT AND PREPARATION OF THE FILTER COMPONENT WITH HYDROPHOBIC AND HYDROPHILIC AREAS FOR COLLOIDAL SEPARATION

The invention relates to a filter component for separating at least one substance from a colloidal system, which is composed of at least two substances, as well as a filter with such a filter component. Furthermore, the invention relates to a method for producing such a filter component.

US 2010/0200512 A1 discloses a filter component for separating at least one substance from a colloidal system, which is composed of at least two substances. This filter component has a filter structure with a filter surface formed by randomly aligned fibers having hydrophobic and hydrophilic properties. Although such a filter component allows the drop magnification of a substance to be excreted of the medium to be filtered, for example of water, but these enlarged droplets are not retained by the filter component, so that they can pass through. Thus, in addition to the first stage of droplet enlargement for a subsequent separation and separation of the further material from the medium to be filtered, a second stage or a second step is required.

From US 2008/0314820 A1 a permeable membrane is known, which has the function that a certain substance is transmitted through the membrane and the other substance is retained. The membrane has projections on the one hand and channel openings on the other, which are provided in the membrane. Through this membrane, whose passages or pores are larger / smaller than the auszuschcheidende medium, there is no increase in drop.

WO 2010/028117 A1 discloses a coalescing medium in which a mixture of two phases can be separated. This coalescing medium comprises a continuous base structure as well as elevations with wettable surface sections arranged on the surface. This provides a coalescing medium for increasing the size of the drops, but these droplets are not retained by the coalescing medium.

Fuel filter systems for cars and trucks currently available on the market are essentially structured in two stages. The filter medium consists of a hydrophobic polyester Meltbrown layer, which is hydrophobic on the inflow side, and a downstream Feinstzellulose for water separation. In this arrangement, the barrier layer used for water separation is on the dirty side of the system. As the particle loading increases, the hydrophobic barrier partially loses its hydrophobicity. With increasing mileage and load of the fuel filter, the Wasserabscheidungsgrad decreases. Downstream system components of the vehicle are then no longer adequately protected.

From WO 2004082804 A1 an alternative filter device is known. Here, a water droplet filter is provided in a housing, wherein the particle filter is preceded by a coalescing element for increasing the droplet, so that the fuel first flows through the coalescing element and then through the particle filter. The disadvantage of this approach is that the coalescing element only achieves a poor filter effect in the case of dispersions with water droplet sizes below 10 μm.

In some countries are prescribed in diesel blends of bio-diesel. Bio-diesel contains residual chemicals (such as glycerol and fatty acid methyl ester). The residual chemicals react in the fuel tank with free water. This results in a very fine dispersion with emulsified in the fuel water droplets whose sizes are between 4 to 10 microns. Such very finely dispersed water-in-diesel emulsions are very stable. With classical filter devices such finely emulsified water can no longer be separated from the fuel flow with a quantitatively sufficient efficiency.

Nevertheless, in order to achieve the required filtering effect, multi-stage water separators have been proposed. For example, a novel filter from the company Mann and Hummel (MTZ 07-08 / 2011, Volume 72, pages 567 to 571) comprises a very fine coalescing filter medium to separate very finely emulsified water droplets first from the diesel and then to larger water droplets to coalesce. By means of further downstream coalescing layers, the water droplets are gradually coalesced into ever larger water droplets. At the downstream end of the filter, a sieve is provided as a hydrophobic barrier layer, in order to prevent a further flow of then still unfiltered water droplets in subsequent vehicle devices.

Known filter components that filter out very fine water droplets have an unfavorable cost-benefit ratio with regard to manufacturing and / or operating costs. These known filter components moreover have multi-stage separators.

The invention has for its object to provide a filter component, which allows a highly effective elimination of at least one substance from a colloidal system over the entire service life and is inexpensive to produce. Furthermore, the invention has for its object to provide a filter that allows an increased degree of excretion. In addition, the invention has for its object to produce such a filter component simply and inexpensively.

These objects are achieved with the independent claims. Advantageous developments of the invention are specified in the respective dependent claims.

The filter component according to the invention has a filter structure with a filter surface, which has at least one repellent and adjacent thereto at least one attractive region for the substance to be ejected, so that the attractive region is provided for increasing the droplet size of the auszuscheidenden substance and the repellent for the substance to be ejected in the colloidal system Retains the substance to be excreted and the at least one further substance can be passed through the filter surface. This filter component allows a one-step elimination of the at least one substance to be rejected from the colloidal system, which is composed of at least two substances. By this structure of the filter structure, on the one hand, a droplet enlargement is achieved on the filter structure. At the same time, on the other hand, a separation of the substance to be excreted and a passage of the at least one further substance through the filter structure. As a result, the efficiency for the excretion of the at least one substance can be increased, in particular also accelerated by the single-stage precipitation. By this structure of the filter structure, a simple adaptation to colloidal systems as well as the substance to be rejected can be achieved.

By forming the filter component with at least one area to be rejected and a repellent area for the substance to be ejected, the substance to be rejected can moreover accumulate on the attracting area. As a result, a rapid growth of the substance to be rejected as well as a droplet formation and subsequently an associated droplet enlargement can take place. After incipient droplet formation, rapid growth of the droplets of the substance to be rejected can occur due to the increasingly enlarging surface, whereby an increased filtration efficiency is achieved.

The filter component preferably has a configuration in which the at least one repellent region and the at least one attractive region for the substance to be rejected in the colloidal system are designed as non-attracting regions for the substance not to be rejected in the colloidal system. As a result, an increased discharge rate for the substance to be discharged can be achieved. An improved growth of auszuschleusenden substance at the attractive areas is thereby made possible.

A preferred embodiment of the filter component provides that the filter structure is designed as a permeable membrane or as a permeable grid, which preferably comprises a two-dimensional structure. Such filter structures are inexpensive to produce and preferably used as a mass product.

Advantageously, the filter structure designed as a grid has a mesh width of, for example, 60 μm on. Preferably, a range of 20 to 190 microns is provided. The size of the mesh size is adaptable to the colloidal system so that increased efficiency is achieved. Preferably, a plurality of grids are associated with each other and form such a filter structure.

The filter structure preferably extends in a plane. As a result, simple two-dimensional layers of the filter structure can be formed, which are cost-effective both in terms of manufacture and enable easy handling during further processing.

According to a preferred embodiment, the filter component has a plurality of filter structures arranged one above the other or to one another and forms the filter component. These filter structures can be arranged in the same pitch to each other or offset from each other.

The filter component preferably has attracting regions for the substance to be released in the colloidal system, which regions comprise a hydrophilic surface or consist of a hydrophilic material and which have areas repellent to the substance to be rejected in the colloidal system and have a hydrophobic surface or consist of a hydrophobic material. Such filter components make it possible, in particular, to use water droplets emulsified, for example, in oil or fuel. These even very fine water droplets attach to the at least one attractive area and, after being attached by the droplet or droplets, form an enlarged attractive area, whereby a rapid growth process is initiated. This increases the elimination rate. The growing droplets can solve themselves in a predetermined size before the attractive area and be discharged into a collecting area. Due to the repellent areas - ie hydrophobic areas - a flow through the non-auszuschleusenden substance is achieved at the same time. Particularly in the case of a bio-diesel admixture in the diesel fuel, a highly effective separation of the water droplets emulsified in the diesel fuel can be achieved.

In the filter structure, which is preferably designed as a grid or membrane, the attractive regions are formed at points of intersection between non-attracting regions. This allows a simple construction and a simple production of such filter structures for a filter component. Alternatively, the intersections may be formed as repellent areas and the intervening areas as attracting areas.

A preferred embodiment of the filter component provides that the at least one attractive region is punctiform. These are preferably formed at the crossing points. As a result, the growth process of the substance to be rejected can be accelerated.

Furthermore, the attractive regions are preferably provided uniformly distributed on a filter structure. This allows simple further processing as well as the installation of the filter components in a filter.

Alternatively, a stochastic distribution can also be provided.

According to a preferred embodiment of the invention, the filter surface of the filter structure has convex elevations. This arrangement has the advantage, in particular in the case of membranes, that an increased surface area for growth of the substance to be eliminated is created by these elevations.

The filter component is preferably used in a colloidal system, which is a fuel, in particular diesel fuel with preferably a bio-diesel admixture, whose substance to be excreted or auszuschleusender are emulsified therein water droplets.

The object underlying the invention is further achieved by a filter for a substance to be rejected in a colloidal system in which a filter component is provided between a supply line and a discharge line in the housing, which is a filter structure with a filter surface for the auszuschleusenden substance in the colloidal system comprising at least one repellent and adjacent to at least one attractive area for the substance to be ejected. As a result, a quasi one-step elimination can be created. This allows not only the saving of production time and material costs but also a considerable reduction of the required installation space for the filter.

The filter preferably accommodates a single-layer or multi-layer filter structure which is arranged vertically. The filter structure is preferably supplied by a colloidal system with a flow direction oriented essentially perpendicular to the filter surface. This vertical arrangement of the filter component has the advantage that the growing droplets accumulate on the attracting areas and, after a predetermined droplet size, detach themselves and can be discharged independently downwards into a collecting area. This means that the attracting areas undergo a dynamic process and are freed again and again independently of the accumulated droplets, so that a re-deposition of the substance to be eliminated with an increase in the droplet size is made possible. In particular, the inflow direction of the colloidal system is substantially perpendicular to the filter surface. As a result, both the growth of the droplet size and the independent downflow and the flow can be in an optimum.

The filter preferably has a catchment area below the filter component for the substance to be eliminated. This can be given a simple construction of a filter. Preferably, the catchment area comprises an emptying or removal opening.

In a housing of the filter, a pre-filter is preferably upstream upstream of the filter component. This pre-filter is used in particular for the separation of entrained in the colloidal system particles. This pre-filter can also be designed as a pre-filter of the substance to be rejected in the colloidal system. In addition, the pre-filter can also be designed as a further filter component for discharging a further substance in the colloidal system.

The object underlying the invention is further solved by a method for producing a filter component for separating at least one substance from a colloidal system, which is composed of two substances, by providing a filter structure which repels and attracts the substance to be rejected Areas comprises, so that the attracting area is provided for increasing the droplet size of the excreted substance and the repellent area holds back the substance to be excreted and the at least one further substance can be conducted through the filter surface.

In this case, it can be provided according to a first embodiment of the invention that at least one repellent and attractive area is applied to the filter structure one after the other for the substance to be ejected. Thus, both the repellent regions and the attracting regions can be applied, for example, by a coating process, so that the starting material for the filter component is independent of at least the substance to be released from the colloidal system.

A further alternative embodiment of the invention provides that the filter structure consists of a material which repels the substance to be rejected and at least one attractive region is applied for the substance to be rejected. As a result, the filter component can be produced in the case of a correspondingly provided base material by only one processing stage.

A further alternative embodiment for the production of the filter component provides that the filter structure consists of an attractive material, which in particular attracts the substance to be rejected, and at least one repellent region is applied for the substance to be removed. This embodiment corresponds in principle to the previous, wherein the base material instead of the repellent material is replaced by an attractive material for the auszuschleusenden substance.

The method for producing the filter component is preferably carried out by a coating method in which the corresponding area is applied by rolling, printing, spraying, steaming, etching. Depending on the filter structure as a grid or membrane and the material used, a corresponding process selection can be made. Depending on the method of applying the coating, a coating may be applied by means of a mask so that specific areas are not coated and the others are again coated to provide a structured configuration and juxtaposition of the diverging and attracting areas.

A further preferred embodiment of the method for producing the filter component provides that after the coating of the filter structure, a contour is introduced. This can be done for example by rolling, in particular by means of pressure.

A further embodiment for producing the filter component provides that the filter structure is provided by a grid of a hydrophilic material and then coated with a repellent, in particular hydrophobic material, such as PTFE and other fluorocarbons, and then by etching, preferably with individual areas the desired structure are introduced. Such a method allows the introduction of defined structures in a simple manner, which allow a simple adaptation of the substance to be rejected in the colloidal system.

The invention and further advantageous embodiments and developments thereof are described in more detail below with reference to the examples shown in the drawings and explained. The features to be taken from the description and the drawings can be applied individually according to the invention individually or in combination in any combination. Show it:

1 shows a schematic, not to scale view of a filter structure of a filter component,

FIG. 2 shows a schematic view of a multilayer filter structure according to FIG. 1 for forming a filter component,

Figure 3 is a schematic view showing the principle of operation of the filter component and

Figure 4 is a schematic sectional view of a filter according to the invention.

1 shows schematically a partial view of a filter component 12 with a preferably single-layered filter structure 14, which is constructed, for example, in the manner of a grid. This filter component 12 is intended to disperse a substance from a colloidal system which consists of at least two substances. For this purpose, the filter component 12 comprises a filter structure 14, which comprises at least one attracting region 16 and at least one repellent region 18 for the substance to be ejected. In the exemplary embodiment, the attractive regions 16 are provided at intersection points 19 and the repellent regions 18 lying between them. These attracting regions 16 may, for example, be point-shaped and be made larger in volume than the repelling regions 18.

The filter structure 14 is preferably designed as a grid and preferably extends in a plane within which the attracting regions 16 and repelling regions 18 are provided in particular evenly distributed.

As an alternative to the filter structure 14 shown in FIG. 1, the attracting regions 16 and repelling regions 18 may also be interchanged so that, for example, the repelling regions 18 are provided in the intersection points 19 and the attracting regions 16 are located therebetween.

FIG. 2 shows an alternative embodiment to FIG. In this embodiment, a two-layered or multi-layered filter component 12 is formed from two or more filter structures 14. For example, the filter structures 14 may be arranged offset to one another such that the attracting regions 16 of the first filter structure 14 are positioned in a gap to the attracting regions 16 of the second filter structure 14. Likewise, a cubic grid may be formed. The arrangement of the individual filter structures 12 to each other can also be made irregular to each other. In particular, in the case of a grid-shaped configuration of the filter structure 14, an irregular arrangement of the individual filter structures relative to one another may be advantageous, resulting in a stochastic distribution of the attracting regions 16 with respect to a plane through which the filter component 12 can flow.

The filter component 12 is preferably provided for the elimination of water or water droplets in fuel, in particular of a diesel fuel, which has, for example, a bio-diesel admixture. In the case of this fuel, it is necessary in particular for the water droplets emulsified therein to be eliminated, in order to avoid damage to the engine, in particular the combustion chamber. For this purpose, the attracting regions 16 are designed as hydrophilic, ie water-attracting regions, and the repelling regions 18 are designed as hydrophobic regions, ie water-repellent regions. Such filter components 12 can also be adapted and used for other colloidal systems.

The aforementioned filter structure 14 allows even very finely emulsified water droplets can be eliminated in the bio-diesel fuel, for example, have a size of less than 10 microns, especially less than 5 microns.

FIG. 3 shows a schematic view of the filter structure 14 according to FIG. 1, with the individual states being represented at the times t1, t2, t3 and t4 in order to better explain the effects of excreting the substance to be rejected, such as water droplets.

This is done as follows: The filter component 14 is flowed through by the colloidal system, wherein preferably an outflow direction is provided perpendicularly or substantially perpendicular to the plane of extent of the filter structure 12. At the attractive areas 16, the droplets 22 of the substance to be eliminated settle in the colloidal system. The repulsive areas 18 remain free. The repellent region 18 is repellent not only for the substance to be excreted, but also for the at least one further substance in the colloidal system, so that attachment does not take place and the filter structure 14 of the further colloidal substance flows through it. Thus accumulate at the time t1 at the attracting region 16, the other droplets of auszuschleusenden substance.

At time t2, further droplets 22 have already attached to the attracting region 16, wherein individual droplets have already grown to larger droplets 22 '. The presence of first droplets 22 at the attracting region 16 increases them by further droplets 22 which accumulate, accelerating the growth of the droplets 22 'due to the ever-increasing surface area of the deposited droplet or droplets 22'.

This increased growth becomes clear at time t3, in which droplets 22 "have already grown, which for example are larger than the attracting region 16.

As the droplets 22 '' continue to grow at time t3, the droplets 22 '' 'reach a size or weight such that the adhesive force of the droplets 22' '' no longer predominates over the growing regions 16. At this point in time t4, the water droplets 22 '"detach themselves and sink downward in accordance with arrow 25. In the process, these droplets 22 can also entrain further droplets which are located underneath and which adhere to the further attractive regions 16. The filter structure 14 of the filter component is preferably arranged upright.

The process of growing the droplets 22 of the substance to be rejected can be increased by enlarging the areas 16 opposite to the repelling areas 18 or having them opposite elevations, thereby giving an enlarged surface. As a result, a discontinuous or abrupt transition region between the attracting region 16 and the repelling region 18 can also be created, which enables improved detachment of the droplets 22.

FIG. 4 schematically shows a sectional illustration of a filter 31 with a filter component 12 according to FIGS. 1 to 3. This filter 31 comprises a housing 32 with a feed line 33, which opens via an opening 34 in a prefilter region 36. In the pre-filter region 36 is a pre-filter 37, which is designed in particular as a particle filter. Additionally or alternatively, this prefilter 37 may have further filter functions. For example, another substance can be eliminated from a colloidal system. In addition, a prefiltration of the substance to be rejected by the filter 31 can be made possible. After flowing through the prefilter 37, the liquid or the colloidal system passes to the filter component 12, which is designed, for example, as a stationary round filter or pipe filter. The liquid is supplied substantially perpendicular to the outside of the filter component 12, flows through the filter component 12 and is led out within the filter component 12 upwards via a preferably centrally disposed on the housing 32 line 41, in particular fuel line, out of the housing 32. Between the pre-filter 37 and the filter component 12, a discharge area 42 is provided, in which the effect described in detail in Figure 3 for separating the substance to be ejected takes place. Below the filter component 12, a collecting area 44 is provided, in which the substance to be discharged, such as water, collects. This may have an emptying 46.

The filter component 12 is preferably arranged standing in the housing 32 of the filter 31. Likewise, an inflow of the colloidal system oriented perpendicular to the filter plane is preferably provided, so that an optimization of the deposition rate of the substance to be rejected is made possible.

Alternatively, the filter component 12 may also be inclined and the flow direction not only perpendicular or substantially perpendicular to the filter plane of the filter component 12 may be provided, but also in a deviating flow angle. The filter component 12 is positioned and received in the embodiment by a holding element 48 in the housing 32 of the filter 31 and fixed in the upper region via a counter-holder 49, preferably interchangeable.

Claims (19)

Filter component for separating at least one substance from a colloidal system, which is composed of at least two substances, characterized in that the filter component (12) has a filter structure (14) with a filter surface, which at least one repellent for the substance to be eliminated in the colloidal system and adjacent thereto at least one attracting region (16, 18), so that the attracting region (16) is provided for increasing the droplet size of the substance to be eliminated, the repellent region (18) restrains the substance to be eliminated and at least one further substance in the colloidal system Filter surface is hindurchleitbar. Filter component according to claim 1, characterized in that the filter structure (14) is formed as a permeable membrane or permeable grid and preferably consists of a two-dimensional structure. Filter component according to claim 2, characterized in that the filter structure formed as a grid (14) has a mesh size of 20 to 190 microns. Filter component according to claim 2, characterized in that the filter structure (14) extends in a plane. Filter component according to claim 2, characterized in that it consists of several superimposed filter structures (14). Filter component according to one of the preceding claims, characterized in that the regions (16) attracting the substance to be rejected in the colloidal system have a hydrophilic surface or consist of a hydrophilic material and the regions (18) repellent to the substance to be rejected in the colloidal system have a hydrophobic surface Have surface or consist of a hydrophobic material. Filter component according to one of the preceding claims, characterized in that the attractive regions (16) are formed at points of intersection (19) of non-attracting regions (18). Filter component according to one of the preceding claims, characterized in that the attractive regions (16) are punctiform. Filter component according to one of the preceding claims, characterized in that the attractive regions (16) are distributed uniformly or stochastically on a filter structure (14). Filter component according to one of the preceding claims, characterized in that the filter surface of the filter structure (14) has convex elevations. Filter component according to one of the preceding claims, characterized in that the filter structure (14) is formed with a filter surface for elimination of water or water droplets in a diesel fuel, in particular with the addition of bio-diesel. Filter for a substance to be rejected in a colloidal system, in particular for separating water in diesel fuel, with a housing (32) having a feed opening (34) and a conduit (41) for discharging the substance not to be rejected, characterized in that a filter component according to one of Claims 1 to 12 is provided between the feed opening (34) and the line (41). Filter according to claim 12, characterized in that a single-layered or multi-layered filter structure (14) is arranged standing in the housing (32), which is flowed through by a colloidal system with a substantially perpendicular to the filter surface of the filter component (14) fed colloidal system. Filter according to claim 12 or 13, characterized in that below the filter component (12) a collecting area (44) is provided for the substance to be eliminated, which preferably has the highest density. Filter according to claim 12 to 14, characterized in that upstream of the filter component (12) is provided at least one prefilter (37) for separating particles and / or the substance to be ejected and / or another ausschleusenden substance. Process for producing a filter component (12) according to claim 1 for separating at least one substance from a colloidal system which is composed of at least two substances, characterized in that a filter structure (14) is provided which one after the other with at least one for the auszuschleusenden fabric repellent and attracting area (16, 18) is applied, or consists of a material which repels the substance to be rejected and at least one attractive region (16) for the substance to be removed is applied, or consists of a material attracting the substance to be removed and at least one repellent region (18) is applied to the substance to be removed. A method according to claim 16, characterized in that the repellent or the attracting region (16, 18) or both by a coating, in particular by rolling, printing, spraying, vapor deposition or etching, are applied. A method according to claim 16 or 17, characterized in that in the filter structure (14) after coating with the at least one region (16, 18), a contour is introduced, in particular that the filter structure (14) with a roller, preferably under pressure , is run over. A method according to claim 16, characterized in that a grid of attractive, in particular hydrophilic material is provided, that the grid with a repellent, in particular hydrophobic material, in particular PTFE, is coated or vice versa and that by etching, preferably with a mask, then the desired structure for producing the filter structure (14) is introduced.

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