DE4418633A1 - Double walled fluid filter matrix unsupported by rigid members - Google Patents

Abstract

The novelty is that in a filter fluid filter process and assembly, the chamber (30) receiving filtered fluid within a flexible filter medium (32) is held free of rigid supports. During the filtration phase the flexible filter medium (32) forms a double layer (32'') around the chamber through which filtered fluid is discharged. Liquid forcing its way through the flexible filter medium (32) migrates outwards by means of drainage channels (26).

Description

The invention relates to a method for burning solid substances (hereinafter also called: cloudy substances) from Suspensio using a suspension room (turbidity room) limiting suspension container and at least one of them Suspension room (turbidity room) with the filter element one of a flexible filter medium opposite the Suspen tion room (turbidity room) delimited pure fluid room (clear room) and in this clean fluid space (clear space) with drainage teln, wherein in a filtration phase a pressure difference between a higher pressure in the suspension space (turbidity space) and a lower pressure in the pure fluid room (clear room) is maintained so that, on the one hand, by narrowing the flexible filter medium pure fluid (filtrate) from the Suspen sionsraum (turbidity room) through the flexible filter medium to the clean fluid room (clear room) and on to the drainage received and derived from these and on the other hand suspended portions (turbidity portions) of the suspension the suspension room side (turbidity room side) of the filter medium accumulate, and in a cleaning phase a pressure difference difference between a higher pressure within the pure fluid space (Clear room) and a smaller pressure in the suspension room (Turbidity room) is built up so that the flexible filter medium undergoes expansion and on the outside of the flexi bile filter media accumulations previously suspended Shares (accumulations of turbidity) loosened and / or discarded become.

Such a method is e.g. B. is known from US-A-4,604,201. In this known method surrounds a tubular Filter element a dip tube. On the dip tube are in uniform distribution around its axis support elements orderly. The filter element is in the filtration phase this support elements and forms between each other following support elements each a sag. If the Cleaning phase is initiated, so the filter element inflated, and the previously formed sags form in  Circumferential direction to each other around the axis of the dip tube closing sections of an envelope, which at the Support elements still attached to a cylindrical tube Form of the filter element results. This means that the individual sections of the filter element a certain Carry out movement when from one condition: great pressure in the cloudy room - smaller pressure in the clear room - to one Condition: higher pressure in the clear room - lower pressure in the Filtrate space - is passed over. The one with one Changes in the direction of the pressure difference the lying between successive support elements However, there are peripheral portions of the filter element hose relatively minor, so with an intense Loosen and reliably throw off turbidity collections from the turbidity side of the filter element can always be expected.

From US-A-4,968,424 a filter element is known which a perforated drain pipe around an immersion tube points. The drainage pipe is cylindrical in one end region and arranged substantially coaxially with the dip tube and there with a sealingly connected to the dip tube Carrier connected. Then to this support disc the other end of the perforated drain pipe this as well as the dip tube itself into a flat, but still rigid ellipse deformed. On the cloudy room side of the drain pipe is a filter bag, which in the Area of the support disc close to the drainage pipe is closed and at the end of the Drainage pipe is closed. The size of the filter bag is approximately dimensioned so that it is elliptical Area of the drainage pipe essentially wrinkle-free on the Drainage pipe is applied. The drain pipe is with a variety  perforations. In the filtration phase occurs Clear liquid of the suspension through the filter bag and that perforated drainage element and can through the immersion tube connected to the interior of the filter bag be drawn. The possibility of larger movements of the filter sacks if the polarity of the pressure difference is reversed However, there is no clear space and cloudy room here, because of the size adjustment of the filter bag to the elliptical cross section of the drainage tube an essential Inflation of the filter bag also in the area of the short ellip is prevented.

From a publication by Fritz Scheibler in 56 Wuppertal-E., Founded in 1871 (with the title "Das pat. Scheibler filters for fine filtration as tissue and an Schwemmfilter ") is still a filtration process knows, in which a bag-shaped sack of rectangular Outline in the area of a corner has a slip opening. In this slip opening is a rectangular frame element-designed drainage means introduced, which through joints in the corner points of the rectangle to a long stretched structure is deformable and in elongated Condition through the slit opening of the filter bag in this can be introduced. After the introduction of the langge stretched structure in the filter bag becomes the rectangular shape of the frame-shaped drainage element restored. Two opposite frame legs of the frame-shaped Drainage elements are then on two opposite Edges of the filter bag, the distance between the edges of the filter bag approximately the maximum distance between the corresponds to the frame elements mentioned. The filter bag is consequently between the legs of the frame-shaped approximately stretched towards the drainage element, however only stretched so far that the filter bag is longitudinal  Direction of the mentioned frame elements on these according to Art a curtain can be gathered into a fold. The gathering is already due to the introduction method unavoidable, because only if the filter bag is too large in the longitudinal direction of the said frame legs, it is over at all possible, the frame-shaped drainage element through the one slip opening of the filter bag into the interior of the filter bag. Between the two mentioned frames elements are orthogonal to these chains or springs spans, which can serve as drainage agents. The fold of the filter bag leads to a large surface of the same. In the filtration phase, the outside of the filter bag again created overpressure compared to that in the Clear space pressure inside the filter bag. Cleaning by swelling is not provided here basically also not feasible. For one thing is impose a narrow limit on inflation, in that the Distance between the above two frame legs approximately corresponds to the bag size in the direction of this distance. To the others it is inconceivable to wrinkle when inflated over the end of the frame-shaped drainage element below Extend the smoothing of the wrinkles as there is no possibility stand in a subsequent renewed filtration phase bring about the wrinkling again. A bloat in folded condition of the bag, on the other hand, would not the desired loosening or / and dropping process from ange flooded accumulations of turbid, as this between successive folds of pinching would.

The invention has for its object in a method of the generic type mentioned at the beginning ensure that movements of the Filter elements occur when the direction changes  Pressure difference between suspension space (turbidity space) and pure fluid space (clear room) is brought about, so that one in the pure fluid overpressure due to the large extent of the Deformation an intense loosening effect on accumulations before suspended portions (turbid substances) occur and these with high probability even under unfavorable conditions will be thrown.

To solve this problem, the invention proposes that the clean fluid space (clear space) within the flexible filter medium is kept clear of rigid support means so far that in the Filtration phase over a large part of its filter medium clean fluid side (clear room side) surface a double layer and the pure fluid penetrating into the filter medium (Clear liquid) within the single layer forming the double layer were the filter medium and / or in an interface between migrated the individual layers to the drainage agents.

Due to the lack of rigid support means, as in the U.S. Patents 4-604,201 and 4,968,424 are provided at a transition from the filtration phase to the cleaning phase correspond to a very large expansion deformation of the filter medium the easing and dropping tendency with regard to the accumulated previously reached suspended portion (turbidity). Is preferred the geometry of the three-rod means and any existing non-star rer support means chosen so that the flexible filter element when an internal overpressure builds up in the suspension space (cloudy room) according to the geometric conditions of the Filterele can inflate freely. This leads to a maximum curl Movement and release movement when applying overpressure within the Clean fluid room (clear room).

The procedure is when filtering suspension on liquid base and also applicable to those based on gas.

The invention relates to those formulated above Task continues to be a filter apparatus, in particular for through implementation of the method defined above  is suitable. This filter apparatus comprises a suspension space (turbid space) delimiting suspension tank, further min at least one filter element within the suspension room (turbidity room) with a limited by flexible filter medium and against the Suspension room (cloudy room) delimited pure fluid room (clear room) and drainage means within the clean fluid space (clear space); furthermore, suspension inflow agents are to the suspension space (cloudy space) and pure fluid drainage (filtrate drainage) from the Drainage means provided. Furthermore, pressure control means provided and designed so that an overpressure in the Suspen sion room (turbidity room) opposite the pure fluid room (clear room) can be maintained during a filtration phase, d. H. during an operating phase in which the pure fluid space (clear space) is concentrated, pure fluid components (clear liquid components) of the suspension in the clean fluid room (clear room) and formerly Suspended parts (turbidity parts) of the suspension on the Suspension room side (turbidity room side) of the flexible filter medium accumulate. In addition, these pressure control means are like this trained that an overpressure in the pure fluid space (clear room) opposite the suspension room (turbid room) can, namely during a cleaning phase, d. H. during a further operating phase, in which the expansion of the flexible filter media collections of previously suspended portions (Accumulations of turbidity) loosened on the filter medium and if necessary by be thrown away. Removal means are also provided hen to collect the previously suspended portions (turbid accumulations) from the suspension room (turbidity room) can.

According to the invention, it is provided that the pure fluid space (clear space) within the flexible filter medium of rigid support is kept clear so far that in the filtration phase Filter media over a large part of its clean fluid room side (Clear room side) top forms a double layer. Still is the structure of the flexible filter medium is such that that in or / and between the individual layers forming the double layer Migration paths for the pure fluid parts (clear liquid parts) of the suspension, which lead to the drainage means.  

The flexible filter medium can in principle be made of one layer forms, for example from a tissue, the tissue structure Pure fluid migration (clear liquid migration) either in the individual layers or between the Individual layers towards the drainage means permitted.

Are they the actual separation between pure fluid (clear liquid speed) and suspended portions (turbidity) forming filter less inherently less suited to such migration paths result, it is provided that the flexible filter means more is layered with a clean fluid space side (clear room-side), shape-stabilizing and / or migration-promoting Layer and with another, the actual separation task fulfilling layer, these layers by differential pressure changes caused by changes essentially together to lead. The stabilizing or migration-promoting layer can doing z. B. be formed by a coarse fabric. It is important that this layer takes part in the movements, which by difference pressure changes are imposed on the actual interface. This is a crucial difference from a device, for example according to US-A-4 968 424, in which the elliptically deformed Drainage pipe always maintains its shape and therefore one through Changes in pressure difference caused deformation of the actual separation layer sets narrow limits.

Keeping the clean fluid space (clear space) free from rigid supports means should not rule out the possibility of orientation can be present, which is the fold layer in the double layers Predetermine education. But it is essential that this orientation means the double layer formation on the one hand and the swelling on the other hand, do not significantly hinder formation, but only to contribute to the orientation of the double layer formation.

An orientation influence for the double layer formation can for example, can be achieved  that the flexible filter means seams and / or permanent fold lines (comparable to the crease of pants), which a certain orientation one with a corresponding one Adjustment of the double layers that set the pressure difference favor education.

On the other hand, the orientation means can also be elastic deformable clamping means for the flexible filter medium be educated, e.g. B. elastically deformable clamping springs. These clamping means can be used, for example, on drainage be supported, which in turn on the suspension operationally attached to a container or on a dip tube can be arranged.

For a filtration device, it is out of cost Operational reasons essential that the total volume, essentially determined by the dimensions of the Suspension container, can be kept small in proportion to the intended filter performance. This demand can in the apparatus construction according to the invention Be taken into account that when accommodating a plurality of Filter elements within the suspension room (turbidity room) the orientation are arranged in such a way that the flexible filter means of individual filter elements with regard to double layer formation and / or expansion, minimal, if any, mutual influence.

Basically, it can be said that the arrangement a plurality of filter elements in the suspension space (turbidity space) so ge should be met that the individual filter elements maximum occupancy of the suspension room (turbidity room) with filter elements themselves neither in the filtration phase nor in the cleaning phase, thus neither in the double-layer-forming state nor in the inflated state affect the condition significantly. The condition "maximum loading  laying the turbid space with filter elements "can be different also expresses: "maximum filter area within the Suspension room (cloudy room) ".

The filter medium of a filter element can preferably be hose be shaped. The drainage means can a dip tube, which is approximately in the center of the tubular filter medium. With one Training is preferred to a vertical orientation of the Immersion tube and the tubular filter medium, because this vertical orientation leads to optimal dropping leads in the cleaning phase. It is basic In addition, the pure fluid discharge (filtrate discharge) either upwards or to let down take place. If the pure fluid drain (filtrate drain) instead of upwards, it is recommended to use the immersion tube and the preferably attached to the dip tube components, so Drainage means and filter element, at the top of the dive pipe, where the dip tube or an associated Collector is led out of the respective suspension container. The same applies in reverse if the pure fluid drain (filtrate drain) done down; then the dip tube is preferred moor at the bottom opposite the suspension tank where it leads out of the suspension tank, and the associated components are also preferred, ie drainage means and filter element, also at the bottom Fasten the end of the dip tube. Other attachment points far from the respective lead-through end of the dip tube are for both the drainage agent and the filter element conceivable.

The fluid migration (liquid migration) to the dip tube can thereby be supported if the dip tube is drained trellis tube is surrounded. Under the trellis tube it becomes uneven a rigid tube respects its geometric structure high fluid permeability understood which Resists forces in the filtration phase by the  Overpressure in the suspension room (turbidity room) are exerted on this trellis.

The rigidity of the trellis tube can be caused by the tube structure itself or due to support on the immersion tube his. If a trellis tube is used, the same applies to this is the condition that on the one hand there is the double layer formation not significantly influenced, but on the other hand also the bloat deformation of the filter element is not significantly hindered. Applied to the case of a tubular filter element, which surrounds a dip tube, this means that the through The diameter of the trellis tube is much smaller than the circumference of the bag-shaped filter element. There, as indicated, that Trellis placed considerable strain during the filtration phase due to the overpressure then prevailing in the suspension space (turbidity space) other measures can also be taken to the migration conditions from the folded to the double layer Parts of the filter element to improve the dip tube. For example, you can provide local grid elements there, where openings of the dip tube the fluid access (liquid access) to the Allow dip tube interior. You can also do the diving outer circumference of the pipe and in the vicinity of at least one opening a drainage pipe or a drainage rod parallel to the dive Arrange the pipe axis. This drainage pipe or drainage stab can then be much smaller in diameter will hold as the dip tube itself, so the demands after not obstructing the double layer formation and after not hindrance of the expansion are easily achievable. The drainage rod or the drainage pipe must be used again here only the condition of a relatively low flow resistance for the pure fluid (filtrate) and can be of any geometri structure and any pore structure. The long Liche form of such drainage pipes or drainage rods, the for example, essentially over the entire length of the Dip tube can then ensure that also a migration of the pure fluid (clear liquid) in the longitudinal direction of the  Dip tube up to the respective opening of the dip tube is possible at which the pure fluid (liquid) is then immersed inside the pipe, supported by - in the Filtra tion phase - maintained within the immersion tube low pressure. The arrangement is particularly favorable such drainage pipes or drainage rods on the outside of the dip tube when the dip tube has a plurality of Openings distributed over an axially parallel surface line having. The dip tube can in particular at one end a pure fluid discharge line (filtrate discharge line) must be connected. In This case can be at the other end and / or at least one point an opening may be provided through its length, through which the interior of the dip tube with the inside of the tubular filter medium formed part of the clean fluid space (clear space) connected is.

As previously assumed, it is a hose shaped filter medium, so this can at least one end be attached to the dip tube, preferably on the that end at which the immersion tube in the suspension area container is introduced.

According to a preferred embodiment, it is thought that tubular filter media to at least one end To connect the connecting disc, d. H. to the peripheral surface this connecting disc, which in turn on the dip tube in the plane substantially orthogonal to its axis can be attached. It is especially in connection discs with a circular or elliptical outline thought to be essentially concentric with the dip tube are.

If there is such a connecting washer, then the extent the connecting disc essentially to the circumference of the hose  adjust shaped filter medium. Applied to the case of one circular connecting disc, this means that their through knife essentially the diameter of the cylindrical bloated, tubular filter medium should correspond.

You then get at least at the connecting disc on a substantial part of the length of the tubular Filter means an essentially wrinkle-free form of Filter media when inflated by internal overpressure, what for the decrease of collections of formerly suspended portions (cloudy accumulations) is particularly cheap.

It is conceivable that tubular filter means only on one Adhere tightly to such a connecting washer at the end other end of the tubular filter means of this sack is closed properly. You then take the bag-like closed End of the tubular filter medium deviations from the Cylinder shape in the inflated state in purchase. But you have but the advantage that the same through this sack-like end a means of orientation has been created at an early stage which Orientation of the double layer formation influenced, namely influenced in the sense that within a suspension container in a number of existing filter media from correspond filter elements mutually neither in the Filtra affect the cleaning phase. If here Tangier is the meaning of a tangent a hindrance to filtration or cleaning. The bag-like closed end of the tubular filter by means of, for example, a seam or through a permanent folding line with orientation function for the double layering should be carried out. The seam doesn't necessarily need to run straight and across the hose axis; she can for example, be pointed downwards like a roof.

The orientation of the double layer formation in the sense of optimal space Use of the suspension room (turbidity room) can also be done on the dip tube  attached elastic clamps are effected, which in the case of a pressure difference between a higher pressure in the suspension space (Cloudy room) and a lower pressure in the clean fluid room (clear room) Try to clamp filter media and thus the resulting Double layers, e.g. B. emerging "butterfly double layers", a un desired tangent with neighboring filter elements completely or to provide largely preventive orientation.

It is also according to a particularly simple embodiment conceivable that the tubular filter means at least one end of the dip tube down to the dip tube diameter is narrowed by gathering its circumferential length.

The flexible filter medium can also be made like a flat bag be formed so that it becomes a in the cleaning phase pillow-like structures inflated. The flat bag can polygonal, in particular approximately rectangular or have a square outline; is also conceivable circular outline. With such flat bag-like Aus The filter medium can be used as a dip tube Drainage means parallel to the flat bag walls in the be inserted inside the flat bag, i.e. from an edge of the flat bag. Then at this point of introduction again a connection between the dip tube and the flat Bag material made so that the inside of the flat bag closed clean fluid room (clear room) from the suspension room (turbidity room) is delimited. In principle, it is also conceivable to have one dip tube on two opposite points of the flat bag edge through the Insert flat bags and possibly several flat bags lined up on the dip tube, the dip tube then through one opening or a group of openings each with the interiors of each flat bag is connected and except half of the flat bags are free of openings.  

Furthermore, it is conceivable to use a connecting pipe as drainage means to bring up to a bag wall, in particular essentially orthogonal to this bag wall. Again, you could have several Arrange the flat bag along a dip tube.

All of the embodiments described here are distinguished by an extremely light construction. Weight loss alone The result is a drastic reduction in the cost of manufacture.

The ratio between the construction volume and the filter area is considerable Lich cheaper than known devices with so-called Filter cartridges.

The production is particularly simple.

Are the filter media on dip tubes and on again Filtrate manifolds attached, so the brackets are less claimed; they can therefore be built lighter and cheaper become.

The clean fluid spaces (clear spaces) within the filter elements are also relatively easily accessible, so that easy cleaning is also possible here is.

The filter elements or their filter media can be made as desired also be intended for "ONCE" use.

The double layers can be essentially plane-parallel. It but wavy double layers are also possible and un harmful.

The double layer formation leads to a mechanical reduction shear loads on structural parts of the apparatus, so that that is why it can be built lighter and therefore cheaper.  

This also leads to long downtimes (filter cycles). Wrinkles education can be largely avoided; so far anyway Wrinkling occurs, the life of the filter materials may, but not necessarily, ver cuts. Shortening the life of the filter material can u. May be tolerated, if other sensitive Parts of the filter material an occasional replacement get hold of. The actual separation function can, for example wise derived from fabrics, but also from felt. If felts are used, the fluid pressure resistance is relatively low. But if the felts have a coarse mesh Sub-tissues can be combined, so there can be one Fluid pressure resilience in the order of magnitude so far reach the set filter candles.

If one speaks of a dip tube, this should The term also includes hoses, possibly branched hoses.

Becomes a tubular filter medium at both ends provided with a connecting washer, so the dip tube in the cleaning phase also as a tie rod between the two Serve washers. Alternatively, as a tie rod bars or ropes between the two connecting disks be used.

The diameter ratio of the dip tube and the connecting washers is preferably 1: 2 to 1: 5.

Textile materials are particularly suitable as filter media Natural fibers or / and plastic fibers or / and metal fibers in question; porous materials other than Serve filter media.

In the case of a tube shape of the filter medium, one becomes seamless manufactured hose proposed. Is this at one end  free, so it can be closed by sewing or welding his.

If the hose is not at one end with the dip tube or other drainage elements is connected, one speaks of a "stocking". In the case of a stocking-like hose a connecting disc is omitted, which leads to another club fold leads.

If the filter medium is multi-layered, the individual can Layers can be separated or assembled together.

In terms of structure, the filter medium can be used as a fabric Knitted or felt.

In the case of multilayered flexible filter media the individual layers can be woven, welded, Gluing or sewing together.

The dip tube can be smooth on the outside, it can but also improved by notching or channeling Drainage effect.

The accompanying figures explain the invention with reference to Embodiments. They represent:

. Figure 1 illustrates a filter apparatus according to the invention;

Figure 1a shows a section through several filter elements along lines Ia-Ia of Fig. 1.

Fig. 2 partially broken a filter element on an enlarged scale;

Fig. 2a shows a section along line IIa-IIa of Fig. 2;

FIG. 2b shows an enlarged section at the location IIb of Fig. 2a;

Fig. 2c is a sectional view corresponding to Figure 2b in a multi-layer embodiment of the filter means.

Figure 2d shows a section along line IIa-IIa in the cleaning phase.

Fig. 3 shows another embodiment of a filter element formed by folding seams with orientation means;

FIG. 3a shows a section along line IIIa-IIIa of Fig. 3;

FIG. 3b phase a section along line IIIa-IIIa in the cleaning;

Fig. 4 shows a modification to Figure 2 with a particularly simple design of a bottom opening of the immersion tube.

FIG. 5 shows a modification to FIG. 3 with orientation means permanently installed on the immersion tube; FIG.

FIG. 5a is a section along line Va-Va of Fig. 5;

FIG. 6 shows a modification to FIG. 2 with a drainage pipe enclosing the immersion tube; FIG.

FIG. 6a shows a section rods in an embodiment with drainage;

Fig. 7 shows an embodiment with directly fixed to the lashed dip tube ends of the tubular filter medium;

Fig. 8 is a flat bag-shaped filter means with associated immersion tube;

Fig. 8a is a section along line VIIIa-VIIIa of Fig. 8;

Fig. 9 is a modification of the flat bag-shaped filter means having a circular outline of the bag;

FIG. 9a is a section along line IXa-IXa in FIG. 9;

Fig. 10 shows another embodiment of a flat filter bag filter means in which an exhaust pipe is inserted through an opening in a side wall;

FIG. 10a is a section along line Xa-Xa of Fig. 10;

FIG. 11 shows a modification to FIG. 9 with a branched exhaust pipe inside the flat-bag-shaped filter medium;

FIG. 11a shows a section along the line XIa-XIa in FIG. 11;

Fig. 11b is a section along line XIb-XIb of Fig. 11 and

Fig. 12 is a particularly space-saving arrangement of filter elements in accordance with one apparatus in FIG. 1,.

In Fig. 1, a suspension container is designated 10 . In the upper part of the suspension container 10 there is a horizontally extending collecting pipe 12 for the filtrate removal, ie for the removal of clear liquid. At this collecting tube 12 , a valve 14 and a pump 16 connect, which lead to a filtrate container. A plurality of filter elements 15 are arranged in a hanging manner in the suspension container 10 . They consistently hang on manifold 12 . The design of the filter elements will be discussed in more detail. The lower end of the suspension container 10 is closed by a hinged lid 17 which is hinged at 18 to the suspension container 10 and can be fixed in the closed position by a closure 19 . In the bottom area of the suspension container 10 , a suspension introduction line 20 can be seen, which is connected to a suspension supply via a valve 21 and a pump 22 . In the upper dome of the suspension container 10 , one can also see a feed line 23 which is connected to a pump 25 via a valve 24 . By means of this pump 25 , cleaning gas, in particular cleaning air, can be supplied to the filter elements.

A filter element 15 can be seen in detail in FIG. 2. This filter element 15 comprises an immersion tube 26 , which is mechanically fastened with its upper end to the collecting tube 12 and connected to the latter. On the dip tube 26 , an upper connecting plate 27 and a lower connecting plate 28 are attached. The dip tube 26 can be a metal tube, plastic tube or ceramic tube, possibly also a hose, in particular a plastic hose. At the connecting disks 27 and 28 , a tubular filter medium 32 is tightly closed, so that a clear space 30 is included. The dip tube 26 has an opening 31 at its lower end adjacent to the connecting disk 28 . The filter medium 32 consists, for example, according to FIG. 2b, of a fabric 32 which is tight enough to pass the liquid of a suspension on the one hand and to retain solids or turbidities suspended in the liquid on the other hand.

The mode of operation of the filter apparatus described so far is as follows:  

In a filtration phase, valve 24 is closed, while valves 14 and 21 are open. The lid 17 is also closed. The pump 22 pumps suspension, for example a suspension of solids, in a liquid into the suspension container 10 , specifically into its cloud space 9 . At the same time, a lower pressure than the pressure of the suspension is maintained by the pump 16 in the immersion tubes 26 and thus also in the clearing rooms 30 . This low pressure can arise from the drop in pressure of the liquid as it flows through the filter medium 32 , so that the pump 16 can be dispensed with. Due to the excess pressure in the turbidity chamber 9 , the filter medium 32 is squeezed into a double layer, as shown in FIGS. 2 and 2b. The filter medium 32 is permeable to the liquid in the suspension, but impermeable to the solids or turbid substances suspended therein. The liquid can therefore pass through the filter medium 32 and migrate in the direction of arrow 34 to the dip tube 26 in an intermediate surface 35 between the two layers 32 'and 32 ''of the filter medium 32 , which together form a double layer 32 '''. The liquid which has passed through the individual layers 32 'and 32 ''can also assume a flow component in the axial direction of the dip tube 26 , so that it ultimately reaches the slot 31 and can be sucked off through the dip tube 26 by means of the pump 22 . It should be noted that the inside of the filter means 32 is essentially free of rigid support structures, if one does not look at the dip tube 26 . The double-layer speed 32 '''is outside of the dip tube 26 substantially at the entire height of the dip tube within the clear space 30 , so that when viewed in section, a butterfly-shaped structure results, as shown in Fig. 2a. Wrinkles only form in the immediate vicinity of the connecting disks 27 and 28 in this operating phase.

On the individual layers 32 'and 32 ''of the double layer 32 ''' accumulate, as shown in Fig. 2a, turbidity or solids in layers 36 . The layers 36 can still support the filtration effect. It is conceivable that, in order to take advantage of this increased filtration effect, the suspension is circulated during the beginning of a filtration cycle until a layer 36 sufficient for the filtration promotion has formed on the individual layers 32 'and 32 ''.

In the later course, there is a continuous flow through the suspension container 10 , in which suspension is continuously fed through the pump 22 to the turbidity chamber 9 and filtrate, ie clear liquid, is continuously drawn off by the pump 16 . Thus, the turbid or solid layers 36 continuously increase in layer thickness. From a certain layer thickness, the flow resistance through the layers 36 may become too great, so that it may be desirable to initiate a cleaning phase. For this purpose, the pump 22 is first switched off and the valve 21 is closed. The clear liquid (= filtrate) still contained in the clearing rooms 30 is drawn off by the pump 16 . Then the pump 16 is also switched off and the valve 14 is closed. Now the valve 37 is opened and the residual suspension from the. Turbidity chamber 9 is pumped out by the pump 38 until the turbidity chamber is free of suspension. In a comparable function according to the invention of a filter, the clear spaces 30 can be emptied by means of compressed air, which is fed into the turbid space 9 of the suspension container 10 and penetrates the solid layer 36 . The pump 16 can thus be omitted in this step. With this compressed air feed, the turbidity chamber 9 of the suspension container 10 can also be emptied, which is preferably done via the valve 37 , whereby the pump 38 can be omitted. Then the valve 24 is opened, and compressed air is pumped into the dip tubes 26 by the pump 25 , for example a compressor, with the valve 37 still open. Despite the air permeability of the filter means 32, this leads to an inflation of the filter means 32 to form cylindrical tubular structures, as shown in FIG. 2d. The air passing through the filter means 32 can escape at 37 . The inflation of the filter means 32 to cylindrical hoses according to FIG. 2d, as a comparison of FIGS . 2a and 2d shows, leads to a very strong deformation of the filter means 32 from the butterfly shape according to FIG. 2a to the cylindrical tube shape according to FIG. 2d. This has the consequence that the solid layers 36 of the individual layers 32 'and 32 ''loosen and fall on the lid 17 . If it has not already been opened beforehand, the lid 17 can be opened so that the solids fall out of the turbidity chamber 9 downwards and can be removed. The dropping of the turbid layers 36 can, if necessary, be supported by shaking movements or by scrapers (not shown).

As soon as the turbid layers 36 are completely thrown off and transported away, the next filtration phase can begin.

In Fig. 1a can be seen an example of an arrangement of the filter elements 15 with the dip tubes 26 and the filter means 32. The arrangement is selected so that the space within the suspension container 10 is used as completely as possible, but the filter elements 15 do not essentially affect one another, neither in the state according to FIG. 2a (filtration phase) nor in the state according to FIG. 2d (cleaning phase) .

In Fig. 2c it is shown that the individual layers 32 'a and 32 ''a of a double layer 32 ''' a can also be double-layered, namely from an actual filter layer 39 b and a coarse fabric layer 40 a, which then together each have one Form single layer of filter medium 32 a. In this way, the migration ability of the liquid can be increased and at the same time the mechanical stability of the filter by means of 32 a. The filtering layer 39 a and the coarse fabric layer 40 a can be glued, welded or sewn at certain points over the surface, so that they collectively from the butterfly state according to FIG. 2a corresponding to the filtration phase in the inflated state according to FIG. 2d move the cleaning phase when blowing air is supplied through the immersion tubes 26 .

In Fig. 2 one can at A recognize the scrim layer 40.

The embodiment of FIG. 3 differs from that of FIG. 2 in that only a single connection disc 27 b is present. The filter means 32 b is closed at its lower end by folding seams 41 b sack-like, below the lower end 26 'b of the dip tube 26 b. Through these folding seams 41 b, the tubular filter 32 b has a memory imprinted on it. This means that the filter means, when transitioning from a cleaning phase into a filtration phase again, so that the direction of the pressure difference between the turbidity chamber 9 and the clear space 30 changes from the cylindrical shape shown in Fig. 3b in the butterfly shape of FIG. 3a passes with the orientation shown there. In this way, unintentional contact of the filter means 32 b in the butterfly position according to FIG. 3a is prevented even if, according to FIG. 1, the filter elements 15 are closely spaced.

According to FIG. 4, the connecting plate 28 c by tabs 42 c by means of welds 43 c and 44 c of the dip tube 26 c is welded so that the lower end of the dip tube 26 c, an opening 31c is formed through which the clear liquid in the Dip tube 26 c can get. Otherwise, the embodiment according to FIG. 4 corresponds to that according to FIG. 2.

In FIG. 5, 26 d elastic Spannele are attached to the dip tube elements 45 attached d. These clamping elements 45 d are strong enough to impose a memory on the filter means 32 d again, so that in the filtration phase the double layer formation repeatedly occurs in the orientation according to FIG. 5 a.

In the right half of FIG. 5, differently shaped elastic clamping elements 45 e with the same purpose are seen before. The clamping elements 45 d and 45 e, however, are dimensioned so weakly in their restoring force that they do not or only insignificantly hinder the formation of cylindrical hoses according to FIG. 2 d in the cleaning phase. Otherwise, the embodiment corresponds to Fig. 5 that according to Fig. 2. also be mentioned, that a greater number is provided of openings 31 d d in the dip tube 26 in FIG. 5.

The embodiment according to FIG. 6 differs from that according to FIG. 2 in that the immersion tube 26 f is enclosed by a grid-shaped drainage tube 46 f. The drain pipe 46 f is centered on the connecting disk 28 f by a hub 47 f, while the immersion tube 26 f is centered by a further hub 48 f. Each of the hubs also provides a seal. Can also be seen in Fig. 6 in that the filter means 32 to the terminal f discs 27 f and 28 f f by means of clamping rings or retaining straps 49 is tightly fixed. The diameter of the drainage tube 46 f is slightly larger than the diameter of the immersion tube 26 f, but significantly smaller than the diameter of the connecting plates 27 f and 28 f and thus also significantly smaller than the diameter of the filter means 32 f in the cylindrically inflated state. Therefore, a double layer formation also occurs here in the filtration phase, as shown in FIG. 2a. From the flow resistance is reduced by the drainage effect of the drainage tube 46 f. A plurality of openings 31 f can again be provided in the immersion tube 26 f.

Since the drain pipe 46 f can be subjected to considerable forces and therefore u. U. The stabilization also needs its length at middle points, an embodiment according to FIG. 6a is also considered. Here are on the outer surface of the dip tube 26 g in the region of the openings 31 g drainage rods 50 g or drainage tubes 51 g provided in register with the openings 31 g. This also significantly reduces the flow resistance. The drainage tubes 51 g can be provided with openings which are aligned with the openings 31 g. The drainage rods 50 g can be porous and liquid-carrying.

According to the embodiment of FIG. 7, a tubular filter means 32 h is again provided. The tubular filter medium 32 h is narrowed at its ends by gathering and fastened by clips or clamping rings 49 h to the immersion tube 26 h sealingly. The lower end of the dip tube 26 h is completed here at 52 h. Elastic tensioning elements 45 h also serve here to orientate the double-layer formation, as shown in FIG. 2a.

In Fig. 8 can be seen on a dip tube 26 i, a flat bag-shaped filter means 32 i, which is closed by two mutually opposing fold seams 41 i and only one pass through for the dip tube 26 i in the area of the fold seam 41 i. The passage between the dip tube 26 i and the folding seam 41 i is also sealed here. The dip tube 26 i has at its lower end an opening 31 i in the interior of the flat bag 32 i. In this embodiment, too, the folding seams 41 i indicate an orientation of the flat-bag-shaped filter means in the butterfly shape according to FIG. 8a.

The embodiment of FIGS. 9 and 9a differs from that of FIGS . 8 and 8a in that on the immersion tube 26 k a flat bag-shaped filter means 32 k is attached, the outline of which is circular.

In the embodiment according to FIG. 10, a flat bag 32 l with an all-round seam 53 l is attached to the end of a dip tube 26 l. The dip tube 26 l is expanded at its lower end to a can 54 l with openings 31 l. The top wall 55 l is sealed against the can 54 l at 56 l. The lower bag wall 57 l is in the filtration phase on the underside of the can 54 l. In the cleaning phase, the flat bag-shaped filter medium 32 l can swell like a pillow again.

The embodiment according to FIG. 11 differs from that according to FIG. 9 only in that the immersion tube 26 m is branched several times inside the flat bag-shaped filter means 32 m.

Finally, FIG. 12 shows a preferred arrangement of the filter elements 15 n according to FIG. 1. The filter means 32 n can be seen both in the butterfly state in accordance with the filtration phase and in the tubularly inflated state in accordance with the cleaning phase. A pack of the individual filter elements 15 n of maximum density can be seen. But you can also see that even in the butterfly state and in the inflated state, no contact is to be expected, which could hinder the filtration or the dropping of accumulated solid layers of solid.

The filter elements 15 ( FIG. 1) can be arranged standing or hanging. Also inclined against the vertical, in particular special horizontal orientation is possible.

The manifolds 12 can also be formed as plate-shaped boxes, so that a two-dimensional array of filter elements can be connected.

In all embodiments with connection plates ( 27 in Fig. 1, 27 b in Fig. 3, 27 c in Fig. 4, 27 d in Fig. 5, 27 f in Fig. 6), the tubular filter elements can be attached to the respective connection plate by tensioning straps be attached, as indicated in Fig. 6 at 49 f.

In the case of long filter elements, it is in any case advantageous, if no drainage pipe 46 f according to FIG. 6 is provided, to provide a plurality of openings ( 31 h) distributed over the length of the immersion pipe, so that good filtrate drainage is possible.

As shown in Fig. 3, it is advantageous for hanging Filterelemen th, at least in the upper region of the respective Filterele element to provide a connecting plate 27 b. With standing filter elements, a connecting disk is preferably provided at the lower end of the immersion tube. During the dip tube 26 acts as a riser for hanging filter elements according to FIG. 2, (not shown) with stationary filter elements the dip tube a downcomer from which the filtrate flows downwards.

In the embodiment of FIG. 3, the fold seams 41 can also b by welding seams, adhesive seams or be replaced by lacing.

By installing the coarse fabric 40 a according to FIG. 2 c, good drainage properties can also be achieved in the respective double layer if the actual filter webs 39 a come to lie so close to one another that sufficient filtrate migration is no longer guaranteed in the intermediate surface formed between them . The coarse fabric is preferably wide-meshed than the actual filter fabric.

Loosening and throwing off the turbidity accumulations can still be further favored by the fact that the inflation by a strong pressure pulse is initiated.  

Instead of the round bag according to FIG. 10, oval or other shaped bags made of flexible material can also be used.

It should be noted in the embodiment of FIG. 11 that there the branches of the dip tube 26 m in length are so measured that they do not significantly obstruct the inflation process. The ends of all branches are expanded and rounded if necessary so that they do not damage the filter material.

The clamping elements 45 d shown in FIG. 5 can be designed simultaneously as drainage means by being tubular or tubular, for example while maintaining the elasticity, and connected to the dip tube 26 d in a liquid-guiding manner. It is also conceivable that the clamping elements 45 d have grooves or grooves running on their outside in the longitudinal direction.

In the embodiment according to FIG. 11, the branches of the connecting pipe 26 m can simultaneously serve as tensioning elements. They are then designed to be elastically deformable and can also reach as far as the edge of the flat-bag-shaped filter medium.

The systems described so far are also appropriate Adjustment of the filter elements to separate suspended ones Particles, in particular solid particles, suitable from gases which contain these particles in suspended or fluidized form The filtration, cleaning, loosening, dropping and Discharge operations are analogous to those described above Operations. For example, the systems for exhaust gas purification or dust separation can be used.

Claims (34)

1. A method for separating solids from fluid suspensions using a suspension space (Trü braum 9 ) delimiting suspension container ( 10 ) and at least one of the suspension space (turbidity space 9 ) ingested filter element ( 15 ) with a flexible filter medium ( 32 ) limited clean fluid space (clear space 30 ) and in this clean fluid space (clear space 30 ) drainage means ( 26 ), wherein in a filtration phase a pressure difference between a higher pressure in the suspension space (turbidity space 9 ) and a lower pressure in the clean fluid space ( Clear room 30 ) is maintained, so that while the flexible filter medium ( 32 ) constricts pure fluid (filtrate) from the suspension chamber (turbidity chamber 9 ) through the flexible filter medium ( 32 ) to the clean fluid chamber (clear room 30 ) and further to the drainage means ( 26 ) and from this is derived and suspended portions (turbidity) of the suspension on the Suspensio nsseite (turbidity chamber side) of the flexible filter medium ( 32 ) and, in a cleaning phase, a pressure difference between a higher pressure within the clean fluid chamber (clear chamber 30 ) and a lower pressure in the suspension chamber (turbidity chamber 9 ) is built up, so that the flexible filter medium ( 32 ) undergoes expansion and loosened and / or thrown off accumulations on the outside of the flexible filter medium ( 32 ) lying portions (turbid material accumulations 36 ), characterized in that the clean fluid space (clear space 30 ) within the flexible filter medium ( 32 ) is kept free of rigid support means to such an extent that in the filtration phase the flexible filter medium ( 32 ) forms a double layer ( 32 ′ ′ ′) over a large part of its purely fluid-side (clear room side) surface, and that in the flexible filter media (32) penetrating filtered fluid (clear liquid) within the double layer (32 '') Forming the individual layers (32 'and 32' ') of the filter means (32) and / or in an intermediate area (35) between the individual layers (32', 32 '' migrated) to the drainage means (26). 2. Application of the method according to claim 1 in suspensions on a liquid basis. 3. Application of the method according to claim 1 in suspensions gas-based. 4. Filter apparatus, in particular for carrying out the method according to one of claims 1 to 3, comprising a suspension space (turbidity chamber 9 ) limiting suspension container ( 10 ), at least one filter element ( 15 ) within the suspension space (turbidity space 9 ) with one of flexible filter medium ( 32 ) delimited and delimited from the suspension space (turbidity space 9 ), clean fluid space (clear space 30 ) and drainage means ( 26 ) within the pure fluid space (clear space 30 ), suspension inflow means ( 22 , 21 , 20 ) to the suspension space (turbidity space 9 ), Purely fluid discharge means (filtrate discharge means 12 , 14 , 16 ) from the drainage means ( 26 ), pressure control means ( 14 , 16 , 24 , 25 , 21 , 22 , 37 , 38 ) suitable for setting an overpressure in the suspension space (turbidity space 9 ) compared to that Clean fluid space (clear space 30 ) during a filtration phase, ie an operating phase in which the clean fluid space (clear space 30 ) is concentrated, pure fluid portions (clear liquid portions) of the suspension reach the pure fluid space (clear space 30 ) and previously suspended portions (turbidity portions 36 ) of the suspension accumulate on the suspension space side (turbidity space side) of the flexible filter medium ( 32 ), these pressure control means ( 14 , 15 , 21 , 22 , 24 , 25 , 37 , 38 ) also suitable for setting an overpressure in the pure fluid space (clear space 30 ) compared to the suspension space (turbidity space 9 ) during a cleaning phase, ie during an operating phase in which accumulations are caused by expansion of the flexible filter medium ( 32 ) before suspended portions (turbidity accumulation 36 ) of this flexible filter medium ( 32 ) can be loosened and / or thrown off, and removal means ( 17 ) for removing accumulations of previously suspended portions (turbidity accumulations 36 ) from the suspension space (turbidity space 9 ) , characterized in that the pure fluid space (clear space 30 ) within the flexible filter by means of ( 32 ) rigid support means that the flexible filter means ( 32 ) forms a double layer ( 32 ''') over a large part of its clean fluid-side (clear room side) surface in the filtration phase and that the flexible filter means ( 32 ) is such Structure has that in or / and between the double layer ( 32 ''') forming individual layers ( 32 ', 32 '') migra tion paths ( 34 ) for the pure fluid portions (clear liquid) of the suspension. 5. Use of the filter apparatus according to claim 4 for treatment liquid-based suspensions. 6. Use of the filter apparatus according to claim 4 for treatment gas-based suspensions. 7. Filter apparatus according to one of claims 4 to 6, characterized in that the flexible filter means ( 32 ) is formed in one layer. 8. Filter apparatus according to one of claims 4 to 6, characterized in that the flexible filter means ( 32 a) is multilayered out with a clean fluid space side (Klarraumseiti gene), stabilizing or / and migration-promoting layer ( 40 a) and a filtering layer Chen ( 39 a), which carry out movements caused by changes in differential pressure essentially together. 9. Filter apparatus according to one of claims 4 to 8, characterized in that orientation means ( 41 b) are provided for the double layer formation, which the double layer formation on the one hand and the expansion deformation on the other hand do not significantly prevent be. 10. Filter apparatus according to claim 9, characterized in that the orientation means ( 41 b) by at least one seam ( 41 b) and / and a permanent fold line ( 41 b) of the flexible len filter means ( 32 b) are formed. 11. Filter apparatus according to claim 9 or 10, characterized in that the orientation means ( 45 d) of elastically deformable clamping means ( 45 d) for the flexible filter means ( 32 d) are formed. 12. Filter apparatus according to claim 11, characterized in that the clamping means ( 45 d) are supported on the drainage means ( 26 d). 13. Filter apparatus according to one of claims 4 to 12, characterized in that the drainage means ( 26 ) on the suspension container ( 10 ) are operationally fixed. 14. Filter apparatus according to one of claims 9 to 13, characterized in that when accommodating a plurality of filter elements ( 15 ) within the suspension space (turbidity space 9 ) the orientation means ( 41 b, 45 d) are arranged such that the flexible filter means ( 32 , 32 d) of the individual filter elements ( 15 ) in the case of double-layer formation and / or expansion deformation mutually influence one another minimally, if at all. 15. Filter apparatus according to one of claims 4 to 14, characterized in that the arrangement of the plurality of filter elements ( 15 ) in the suspension space (turbidity chamber 9 ) is such that the individual filter elements ( 15 ) with maximum occupancy of the suspension space (turbidity chamber 9 ) with filter elements ( 15 ) affect neither in the filtration phase nor in the cleaning phase. 16. Filter apparatus according to one of claims 4 to 15, characterized in that the flexible filter means ( 32 ) is tubular. 17. Filter apparatus according to claim 16, characterized in that the drainage means comprise a dip tube ( 26 ) approximately in the center of the tubular filter center ( 32 ). 18. Filter apparatus according to claim 17, characterized in that the dip tube ( 26 ) is connected at one end to a filtrate discharge line ( 12 ) and at its other end and / or at least one point in its longitudinal extent through an opening ( 31 ) with the within the tubular filter means ( 32 ) formed part of the clean fluid space (clear space 30 ) is connected. 19. Filter apparatus according to claim 18, characterized in that the immersion tube ( 26 f) is surrounded by a drainage grid tube ( 46 f). 20. Filter apparatus according to claim 18, characterized in that a drainage tube ( 51 g) or a drainage rod ( 50 g) runs parallel to the dip tube axis and is adjacent to at least one opening ( 31 g) on the outer circumference of the dip tube ( 26 g). 21. Filter apparatus according to one of claims 17 to 20, characterized in that the tubular filter means ( 32 ) is attached to the dip tube ( 26 ) at at least one end. 22. Filter apparatus according to claim 21, characterized in that the tubular filter means ( 32 ) is connected at least at one end to a connecting disc ( 27 , 28 ) which is attached to the immersion tube ( 26 ) in the plane substantially orthogonal to its axis. 23. Filter apparatus according to claim 22, characterized in that the connecting disc ( 27 , 28 ) has a circular outline and is substantially concentric with the immersion tube ( 26 ). 24. Filter apparatus according to claim 23, characterized in that the diameter of the connecting disc ( 27 , 28 ) corresponds in wesent union to the diameter of the tubular filter means ( 32 ). 25. Filter apparatus according to one of claims 17 to 24, characterized in that the tubular filter means ( 32 b) is tightly connected at one end to a connecting disk ( 27 , 28 ) and closed at the other end in a bag-like manner (at 41 b). 26. Filter apparatus according to claim 21, characterized in that the bag-like closed end of the tubular filter means ( 32 b) as a seam or permanent fold ( 41 b) with orientation function for double-layer formation is out. 27. Filter apparatus according to one of claims 17 to 26, characterized in that on the immersion tube ( 26 d) elastic Aufspannklam mern ( 45 d) for mounting the tubular filter means ( 32 d) are attached in the direction of the double-layer formation. 28. Filter apparatus according to one of claims 17-21, 26 and 27, characterized in that the tubular filter means ( 32 h) at least one end of the dip tube ( 26 h) is narrowed down to the diameter of the dip tube by circumferential gathering. 29. Filter apparatus according to one of claims 4 to 15, characterized in that the flexible filter means ( 32 i) is designed like a flat bag. 30. Filter apparatus according to claim 29, characterized in that the flat bag-like filter medium ( 32 i) has an approximately rectangular outline. 31. Filter apparatus according to claim 29 and 30, characterized in that the flat bag-like filter means ( 32 k) has an approximately circular outline. 32. Filter apparatus according to one of claims 29 to 31, characterized in that a dip tube ( 26 i) is designed as a drainage means parallel to the flat bag walls in the flat bag ( 32 i). 33. Filter apparatus according to one of claims 29 to 31, characterized in that a connecting pipe ( 26 l) is passed through a bag wall ( 45 l) as drainage means and is not connected to this. 34. Filter apparatus according to one of claims 11 to 33, characterized in that the elastic deformable clamping means ( 45 d) are simultaneously designed as drainage means.