CH702303B1 - Filter for removing dust from process air in a process equipment and process equipment with such a filter. - Google Patents

Abstract

A filter (10) is used for dedusting process air in a process apparatus. The filter (10) has a support body (11), around the outside of which a textile cloth-shaped filter material (48) is laid. It is proposed that the support body (11) is formed as a wave-shaped vertically folded sheet (12) around which the cloth-shaped filter material (48) is placed.

Description

The invention relates to filters for dedusting process air in a process apparatus, in particular from a fluidized bed apparatus, with a support body, on the outside of which a textile cloth-shaped filter material is placed,

The invention further relates to a process apparatus, in particular a fluidized bed apparatus, with a process chamber in which a particulate material is movable by means of process air and having a filter device arranged at the upper end of the process chamber.

Such filters are offered for example by the company WOKU Filter Media GmbH & Co. KG, Bad Lauchstädt, Germany. Comparable filters are also offered, for example, by Unifil AG Filtertechnik, Niederlenz, Switzerland.

Process apparatuses for treating particulate material which have filter devices in which such filters are used are known, for example, from EP 1 732 666 B1.

The known filters are constructed so that a textile cloth-shaped filter medium is placed over a support body. Has the support body roughly the shape of a hollow cylindrical structure, is usually spoken of a support basket. About the basket, the filter medium is pushed in the form of a closed at one end hose.

Has the support body rather the geometry of a rectangular frame, is spoken of a support frame to which the filter medium is pushed in the form of a closed-sided filter bag.

These filters have in common that they are open at one end. These filters are used to filter out a particulate material from a gaseous medium. For this purpose, the gaseous medium flows from the outside through the correspondingly fine-meshed filter medium into the interior of the filter and leaves it at the one open end.

The mesh size of the textile filter material is chosen so that the gaseous medium can pass, but the particulate material is retained. Such filter systems have found in particular a wide use in fluidized bed apparatus, in particular in the pharmaceutical field.

In the pharmaceutical field very fine dusty powders in the range between 10 and 50 microns are often processed, which are fluidized in the fluidized bed apparatus and depending on the treatment, for. to larger agglomerates are combined (granulation), or applied to existing cores as a layer gradually (pelletizing). To generate a fluidized bed, a gaseous medium, so-called process air, must be constantly moved through the process chamber. In the process, a fluidized bed is established on circulated particulate material. Since the process air escapes from the fluidized bed and is discharged from the process chamber, it can not be ruled out that fine particles of good material are thereby entrained. Therefore, it has become common in such a process chamber in the upper end region, to which the process air flows, to provide filter devices which contain the aforementioned filters. These filters are mounted as so-called hanging filter cartridges, ie, the upper open end of the filter is embedded in a cover plate, so that only the covered with the end closed hose or with the filter bag areas of the filter protrude into the process chamber, or depend in this ,

During dedusting process, the process air enters from the outside through the filter material into the interior of the filter and is discharged through the upper open end of the process apparatus.

Since it may be particularly valuable in the pharmaceutical field in the retained by the filters fine solid particles, these filters are periodically backwashed, with the aim to replace the adhering to the outside of the filter material particles again, so that these back fall into the fluidized bed and be included in a treatment process there. In such a rinsing process scavenging air is blown into the interior of the filter in a burst-like manner and thereby inflates the textile cloth-shaped filter material. In addition, the blow-off air passing from the inside to the outside ensures that the particles retained on the outside are detached.

Therefore, the textile filter material is relatively loosely around the support body around, so that certain wafting movements during Ausfiltervorgang or corresponding balloon-like swelling movements during Spülblasvorgang are possible.

In order to have the largest possible active filter area available, the support body are constructed of rod-shaped material.

In a support basket rods that extend along generatrices of a hollow cylinder, connected to the bottom and cover-side annular or disc-shaped bodies. Since these support bodies are usually made of metallic materials, the corresponding rods are welded to the bodies to do so. The same applies to approximately rectangular frame-shaped support body as a support body for filter bags, which are composed of rods or profile material.

In these filters, the problem is that due to the relatively loose support of the textile material in the dedusting the outside of the process air passing through the textile filter material against the rods or bars, in particular the corners and edges of the support body presses. Since the process air guide is usually not constant, but is also subject to certain pressure surges, the aforementioned wafting movement takes place, with the result that the filter material is constantly rubbing back and forth on the support body.

Therefore, the support body must be reworked very expensive after welding, in particular to smooth the joints. Therefore, it was also attempted to replace the support body with a perforated metal sheet having a predetermined hole profile.

All of these constructions have the disadvantage that their inside is hardly accessible for cleaning and in particular for the cleaning control.

Considering the aforementioned range of application in the pharmaceutical industry with the appropriate hygiene regulations, it is obvious that such a filter not only needs to be cleaned after use, but also must be disinfected and, where appropriate, must be sterile. It is possible to discard the textile cloth-like filter material after use, but the actual support body must, before a new tube or a new bag are reared, be cleaned accordingly. Any edges or sharp points also involve the risk that damage will be caused when the filter stockings are pulled onto the support body, so that the filter effect is lost.

A particular problem is the unrational production of such support body, both in the use of stainless steel rods as a lattice welded construction as well as in the use of perforated metal sheets. For punched sheets, a sharp cut edge and a retracted, smoothed edge always occur when punching. In any case, with great effort, the sharp cutting edge at the holes to smooth mechanically. Welding points in lattice welded constructions are complicated to smooth by mechanical means.

It is therefore an object of the present invention, in a rational way and in particular to create pharma right such support body.

According to the invention the object is achieved in that the support body is formed as folded around fold lines sheet, standing up on both sides of the original sheet plane folds to which the cloth-shaped filter material is placed.

This measure now has numerous advantages.

Such a folded sheet can be made of a single piece of material by a folding / bending operation, wherein the original material may be a flat smooth material. The term sheet metal now includes not only metallic materials, but also plastic materials, provided that they have the corresponding mechanical properties and stabilities and also comply with pharmaceutical regulations.

If such sheet metal material folded around fold lines, a body that can be quite commonly referred to as a "folding plate". The folds are high on both sides of the outgoing sheet metal level. The folds themselves can now assume different geometric configurations, as will be described and explained in more detail below. As a general or superordinate concept, it should be considered that a fold rises from the original sheet plane and returns to the original sheet plane via a gently rounded end. Seen from one side of the sheet, several laterally spaced apart such folds are present. As seen from the opposite side of the sheet, it is equally, that is, corresponding folds are also seen from this sheet plane. A fold that is upstanding from one side merges into another fold that protrudes from the opposite side. The cloth-shaped filter material is now designed so that it is placed around the outer contour of the folded sheet, in such a way that it occupies or spans the outer ends of the folds. The space between two folds spanned by the filter material then represents the interior of the filter in that area. Viewed above the vertical height of the corrugated sheet, then the filter material lies on the crests or outer rounded ends of the folds extending over the height at. Since the filter material covers the body so that one end, namely the upper end, remains free, the gaseous medium can enter from the outside through the filter material into the respective interiors between two folds and then flow up to the open end and out there be removed from the filter. In the process, the fine particles to be filtered out, which are entrained by the gaseous medium, are retained on the outside by the filter material. These conditions, ie such interiors between two upstanding folds, are present on both sides of the sheet plane, so that a relatively large active filter surface results, namely in each case the regions between the upstanding folds spanned by the filter material. Since the outer ends of these folds are rounded, there is no risk that the moving filter material applied to these curves will be damaged. These curves are accomplished in the original bending or folding process and thus make no elaborate reworking necessary. Such folded sheets can be exposed to extreme surface loads without collapsing. Due to the enormous reinforcement of the sheet designed in this way, this can not coincide even with extremely high pressure load of the filter due to excessive air flow load and the resulting filter resistance.

Thus, the problem is completely solved.

In a further embodiment of the invention, outer ends of the upstanding folds of the folded sheet present an outer circumferential contour, against which the cloth-shaped filter material is applied.

That is, seen by the choice of the amount of folding against an outermost ground plane of the sheet and by forming different heights different geometries and sizes, ie in particular cross-sectional or peripheral geometries can be produced.

For example, if the sheet folded so that all folds are the same height, creates a support body with a peripheral contour, seen transversely to the vertical fold lines, which is approximately rectangular.

If the folds rise steadily as seen from a lateral outer edge approximately to the middle and fall off again, a peripheral contour results, which may be oval or even circular.

The choice of shape in the folding process opens countless different geometries of support bodies. The cloth-shaped filter material must then be appropriately cut and optionally sewn or welded to form each of the peripheral contour of the supporting body to be covered, be it in the form of a rectangular pocket or in the form of a cylindrical tube.

Thus, it is thus possible to create by corresponding folding operations circumferential contours, which are formed from roughly rectangular over oval to circular.

In a further embodiment of the invention, the cloth-shaped filter material is placed under such a loose tension around the folds, that this is partially hineinbewegbar by the process material passing through the filter material process air between two adjacent folds.

This measure has the advantage that thereby the desired wafting movements in the filter operation are possible. In the cleaning mode, the filter cloth can then be inflated into a balloon-like hose or other body in order to remove any accumulations of solid particles in a jerky manner.

In a further embodiment of the invention, the height of the folds decreases over a vertical fold line seen from top to bottom.

This measure has the advantage that seen from bottom to top, so over the height of the filter, more and more interior air transport is available. This means that process air that has entered through the filter material in the lower tapered area does not block the entry of process air in higher areas because it permanently has a larger space inside the filter. This results in an optimal filtering effect over the entire height of the filter.

In a further embodiment of the invention, the vertical side edges of the folded sheet are rounded.

This measure has the advantage that these lateral end portions are provided with gentle curves around which the filter material runs. Such curves on the lateral edges of the sheet are also very easy to manufacture manufacturing technology.

In a further embodiment of the invention, the surface of the folded sheet is smooth.

This measure has the advantage that, starting from a smooth sheet material, then correspondingly smooth folds arise over which the filter material can rub back and forth without the risk of cuts or injuries of the filter material.

In a further embodiment of the invention, the folded sheet is provided at the upper end with a closure flange.

This measure has the advantage that the filter can be mounted on this end flange. At this end flange and a corresponding end of the filter cloth can be created or attached. As a result, the entire circumference can be covered with the filter material very simply, with the exception of the upper end opening.

In a further embodiment of the invention, the folded sheet has a border frame at the lower end.

This measure has the advantage that bordered by this border frame the lower end of the support body, that is to say can be closed.

In a further embodiment of the invention, the folds are formed such that a rising and a falling edge of a fold parallel to each other.

This measure has the advantage that thereby a mechanically particularly stable folded sheet is formed.

In a further embodiment of the invention, the mutually parallel edges are adjacent.

This measure has the advantage that between two adjacent folds prevails a relatively large interior, which is delimited by the resulting double wall of the two adjacent flanks. This embodiment is particularly stable against such mechanical forces, which act directed at the original sheet plane on the filter.

In a further embodiment of the invention, areas of the sheet are present between the folds, which extend in the direction of the sheet plane.

This measure has the advantage that in each case a bottom of an interior section between two upstanding folds is formed by these areas. If the areas are so long that they extend over the entire distance between two folds, thus creating a completely closed floor between two upstanding folds. This measure has the advantage that over the entire width of the filter seen this is separated by the bottoms in two halves. This opens up the possibility that when cleaning the filter only one half of the filter interior can be blown in succession with full blowing pressure, which has a particularly effective cleaning result.

In a further embodiment of the invention, the folds are formed as wave crests.

The resulting corrugated body can be referred to as corrugated metal and is mechanically stable as such and the two outer sides are easily accessible after cleaning the filter bag or the filter bag cleaning. By correspondingly gently formed curves of the wave crests or the wave crests can be ruled out that the cloth material rubs so much during the wafting movements that injury or damage may occur. A corrugated sheet is very easy and easy to manufacture with conventional devices on folding or deep drawing operations. A corrugated sheet has sufficient mechanical stability even with thin material thicknesses of <1.0 mm, in order to endure pressure surges occurring during a pneumatic cleaning.

In a further invention, in a process apparatus according to claim 13, which is provided with filters according to the invention, it is provided that a device for blowing cleaning air into the interior of the filter is provided above the filters.

This measure has the advantage that the filter can be blown out in a simple and effective manner.

In a further embodiment of the invention, a plurality of circumferentially juxtaposed depending filter are provided, over which a blower of the device for blowing cleaning air runs, each of which blows a filter with cleaning air while covering its nearest neighboring filter.

This measure has the advantage that a particularly effective cleaning can be achieved. Because the filters adjacent to one another on both sides of a filter are covered by covers arranged laterally from the blower shoe, no process air can enter this filter at this time from the outside. These filters are blocked for a short time. Only the middle filter between these two is blown off. By blocking the two adjacent filters, it is then ensured that the solid particles blown off by the intermediate filter fall downwards in the direction of the fluidized bed and are not moved or sucked in the direction of the adjacent filters. This results in a particularly effective cleaning.

In a further embodiment of the invention, filters with a non-circular circumferential contour, viewed along the longer cross-sectional axis, extend along radii of a circular process chamber.

This measure has the advantage that relatively many filters and thus a large filter surface can be arranged in the process chamber by the star-like arrangement, so that an effective dedusting of process air is possible.

In combination with the revolving blower, cleaning of the individual filters is also possible on an ongoing basis, so that any retained solid particles can be returned to the process in the process chamber as soon as possible.

It is understood that the features mentioned above and those yet to be explained not only in the specified combinations, but also in other combinations or alone in the context of the claims are used.

The invention will be described and explained in more detail with reference to the accompanying drawings.

In the drawings: <Tb> FIG. 1 <SEP> is an exploded perspective view of a first embodiment of a support body according to the invention, <Tb> FIG. 2 <SEP> a development of the corrugated sheet of FIG. 1 before the folding process, <Tb> FIG. 3 <SEP> a section along the line III-III in Fig. 1, <Tb> FIG. 4 <SEP> is a section along the line IV-IV in Fig. 1, <Tb> FIG. 5 <SEP> the supporting body shown in Fig. 1 in the assembled state, <Tb> FIG. 6 <SEP> a situation in which a pocket-shaped filter medium is being pushed onto the support body of FIG. 5, <Tb> FIG. 7 <SEP> a plan view of the final assembled filter, <Tb> FIG. 8 <SEP> a bottom view of the filter, <Tb> FIG. 9 <SEP> a longitudinal section of the filter of FIG. 7 along its shorter oval side, <Tb> FIG. 10 <SEP> very schematically a process apparatus with filters according to the invention, <Tb> FIG. 11 <SEP> the section bounded in Fig. 10 with a circle on a larger scale, <Tb> FIG. 12 <SEP> is a section along the line XII-XII in FIG. 10, <Tb> FIG. FIG. 13 is a view similar to the upper half of FIG. 3 of a second exemplary embodiment, wherein the adjacent filter medium is indicated, FIG. <Tb> FIG. 14 <SEP> a third embodiment according to the illustration of FIG. 13, <Tb> FIG. 15 shows a fourth exemplary embodiment, a portion of which corresponds to the lower half of the representation of FIG. 3 being shown here, FIG. <Tb> FIG. 16 is a representation of a fifth embodiment corresponding to FIG. 15, FIG. <Tb> FIG. 17 is a view corresponding to the representation of FIG. 3 of a sixth exemplary embodiment, which opens into a filter having a circular peripheral contour, FIG. <Tb> FIG. FIG. 18 shows a representation of a seventh exemplary embodiment corresponding to the representation of FIG. 3; and FIG <Tb> FIG. 19 <SEP> is a view corresponding to the illustration of FIG. 4 of the seventh embodiment.

A first exemplary embodiment of a filter according to the invention shown in FIGS. 1 to 9 is designated in its entirety by the reference numeral 10.

The filter 10 has a support body 11 shown in FIGS. 1 to 5.

The support body 11 consists essentially of a corrugated sheet 12 with approximately rectangular contour 14. The support body 11 has a height 16 and a width 18.

The corrugated sheet 12 was made by a folding operation of a flat sheet 12, as shown in Fig. 2.

The originally flat plate 12 was folded along vertical fold lines 20 and 20 so that, seen from one side on the rectangular contour 14 of Fig. 1, a wave trough 22 follows a wave trough 24, which in turn into a wave crest 26 passes.

From the opposite side, it is exactly the opposite, from this side, the wave trough 24 represents a wave peak 26.

Looking at the sectional view of Fig. 4, so the lower end of the support body 11, it can be seen that, starting from a central ground plane 28 which corresponds to the original plane of the sheet 12 of Fig. 2, the wave crests elevate the same height 30 as the opposite wave peaks around the height 32. Between the wave crests 22 and the nearest wave trough 24 and the subsequent wave peak 26, the wavy line runs approximately straight, thus approximately corresponding to a sine wave. This means that the wave crest 22 goes from the ground plane 28 directly into the wave trough 24, this then back into the crest 26. The two outer vertical side edges 34 and 36 are bent in lease of the support body 11 rounded. The sheet 12 has a wall thickness between 0.6 and 1 mm and in the illustrated embodiment consists of a polished stainless steel. As a result, it is suitable for use in filters which are used, for example, in the pharmaceutical sector.

If other applications are desired that do not meet such high hygiene requirements, plastic materials or thermoplastics can be used, which can be brought into such a waveform.

From the sectional view of Fig. 3 it can be seen that at the upper end of the support body 11, the height 30 of the peaks 22 and the depth 32 of the next wave trough 24 is greater than at the lower end.

In addition, the height of the wave peaks 22, seen from the side edge 34, initially increases steadily, reaches a peak approximately at the middle of the width 18 and then decreases again to the opposite vertical side edge 36. The same applies to the opposite wave peaks 26 and their height 32.

Overall, thus results at the upper end of a support body 11 with an approximately oval peripheral contour 40, as shown in particular in FIG. 7 can be seen.

At the upper end 58 of the support body 11, a closure flange 42 is provided, which can be placed suitably on the upper end of the folded sheet 12. Therefore, the contour of this end flange 42 corresponds to the peripheral contour 40.

As can be seen from FIGS. 1 and 5, the lower end of the corrugated sheet 12 is provided with a closed border frame 44, which closes the lower end of the support body 11. By this border frame 44, the plate 12 and the space between the corresponding troughs and crests to the bottom is completed.

The assembled state is shown in Fig. 5.

In Fig. 6 it is shown that just from the bottom a filter pocket 46 is pushed onto the support body 11. The filter bag 46 consists of a textile cloth-shaped filter material 48 which has been sewn together to form a pocket. At the upper end, the filter pocket 46 has a flange 50 which corresponds approximately to the peripheral contour 40 of the upper end of the support body 11

At the lower end 47, the filter bag 46 is closed, as shown in particular in FIG. 9 can be seen.

From the illustration of Fig. 6, the filter bag 46 is still so far moved up until the flange 50 abuts the underside of the end flange 42, as shown in particular in FIG. 9 can be seen. "

In this final assembly state of the filter 10 is now realized.

The upper end 58 of the filter 10 is open, as can be seen in particular from the section of Fig. 9. At the bottom of the filter 10 is closed by the bottom 47 of the filter bag 46. The laid around the outside of the sheet 12 textile filter material 48 is relatively loose.

If the filter 10, as will be explained below, installed in a process apparatus to filter 52 particulate Gutteilchen 54 from the process air, the process air 52 enters via the outside through the textile filter material 48 into the interior 56 of the filter 10 into it , As can be seen in particular from FIG. 8, the pressure of the process air 52 flowing through the textile filter material 48 can be used to push it somewhat into the area between two wave crests. Since the process air 52 has a pulsating component, a more or less swirling surface of the textile filter material 48 results on the outside of the filter.

The mesh size of the textile filter material is selected such that the particulate material particles 54 are retained, while the process air 52 flows through the textile filter material 48 into the interior 56. The process air 52 flows out via the open-top end 58 of the filter 10, as can be seen in particular from FIG. 9.

If, after a certain period of time after which certain accumulations of particulate material particles 54 have formed on the outside of the textile filter material 48, cleaning air is blown in through the open end 58. In this case, as is known per se, the textile filter material 48 inflates in a balloon-like manner, and the good particles 54 adhering to it are removed from the outside by the blowing or cleaning air now passing from the inside to the outside and can either be removed or reused , as will be described below.

The process air flowing in via the outside is in each case the space between two wave crests and the wave trough arranged therebetween.

Due to the V-shaped expansion upward (see Fig. 9), this space is getting bigger, so that seen over the entire height of the filter 10 process gas can occur evenly.

FIGS. 10 to 12 now show a process apparatus designated in its entirety by the reference numeral 60.

The process apparatus 60 has an upstanding cylindrical wall 62, in the lower region of a bottom 64 is provided. The floor 64 has numerous passage openings 68, through which process air 52 can pass from an inflow chamber 66 through the floor 64 into a process chamber 65. A particulate material 54 received on top of the bottom 64 is circulated through the process air 52 to a fluidized bed 72. The process air 52 exits the fluidized bed 72 and flows upwards in the direction of a filter device 76. Good particles 54 entrained thereby are to be filtered out by the filters 10 of the filter device 76.

It can be seen in particular from the sectional view of FIG. 12 that the filter device 76 has a total of sixteen filters 10, as described above.

The sixteen filters 10 are arranged in a star shape in such a way that they extend along radii 67 of the approximately circular process chamber 65. The sixteen filters 10 are installed so that their upper open end 58 each opens into a correspondingly shaped mouth opening 84 in the partition plate 74.

Above the separating plate 74, a device 80 for blowing off or pressurizing the interior 56 of the filter 10 with blown air 88 runs around.

The device 80 has a blower shoe 82 rotating about a central axis 81, the mouth 83 of which can each come to rest congruently over an orifice 84 in the separating plate 74.

As can be seen from FIG. 12, the blower shoe 82 has lateral covers 86 which, when the blower shoe 82 is above a filter 10, cover the respectively adjacent filters 10.

Blast air 88 can now be blown in through the open-top end 58 of a filter 10 via the blower shoe 82, the textile filter material 48 being inflated and thus adhering particulate good particles 54 being detached, so that they fall back onto the fluidized bed 72 and can be included in the treatment process there.

The cover 86 has the advantage that during the blowing process on the filter 10, the adjacent filters 10 are virtually shut down, so that there is no risk that the detached from the filter 10 Gutteilchen in the immediately adjacent filter 10th Be sucked in.

This represents a particularly effective purification.

FIGS. 13 to 19 show further exemplary embodiments of bent or folded metal sheets, which are also within the scope of the present invention.

In all the following embodiments, it is common that the textile filter material is guided around a circumferential contour predetermined by the corresponding peaks or folds.

In the illustrated in Fig. 13 the second embodiment of a filter 90, the sheet 92 is bent so that the wave crests are formed as domes 94 with approximately parallel flanks 95, 97. Between the domes 94, the sheet 92 extends partially in the original ground plane 96. This creates a particularly stable support body.

The circumferential contour 98, which is represented by the deferred textile filter material is again approximately oval, wherein the support points each represent the round crests of the dome 94. Again, the side edges of the original flat starting sheet are rounded.

In the third embodiment of a filter 100 shown in Fig. 14, the horizontal cross-sectional structure of the formed sheet 102 is such that the waves 104 correspond to the teeth of a gear. Again, there is an approximately oval peripheral contour.

In the illustrated in Fig. 15 the fourth embodiment of a filter 110, the sheet is bent so that teeth 112 result, which have approximately parallel flanks 114.

In this embodiment, extremely high pressures or sudden Pulsierbewegungen be included, also the textile filter material 116 is only quasi punctiform or seen over the height of relatively narrow ridges of the teeth 112 at.

In the fifth exemplary embodiment of a filter 120 according to the invention shown in FIG. 16, the metal sheet is folded such that domes 122 with approximately parallel side edges form as folds, which respectively pass over curved regions 124 into the corresponding fold or dome , Again, there is an approximately oval circumferential contour of the filter material 126 placed around it.

In the sixth embodiment shown in Fig. 17, the sheet is bent so as to yield crests 132 whose crests lie on a circular peripheral contour 142. The respective wave crests 132 merge via rectilinear flanks 134, 136 into the respective opposite wave crest.

From the laterally outermost flanks 144, 146 additional wave peaks 145, 147 are expressed which serve to "round off" the circumferential contour 142.

Thus, it is also possible to form a base body of a filter 130 or fold out of a flat sheet, the peripheral contour 142 ends in a circle.

That is, in this embodiment, the bent sheet metal replaces a support body composed of profile bars and end rings or plates around which a round filter stocking is laid.

Here it is particularly apparent that all sides, in particular the flanks 131, 131 of a cleaning are easily accessible. If this is formed from a sheet with a smooth surface, a corresponding body is created with a smooth surface on all sides, which is not only easy to clean, but can also be placed around the friction-reducing filter sock.

In the seventh embodiment of a filter 150 shown in FIGS. 18 and 19, the sheet metal 152 is folded such that folds 153 and 154, which are upstanding from the sheet plane 155, are formed, in which the respective flanks 157 and 158 lie against each other. The opposite folds 153 and 154 merge directly into each other and rise approximately at right angles to the sheet plane 155. The area between two adjacent folds 153 is completely closed by the sheet 152, so that seen left and right of the sheet plane 155 closed at the bottom interior 156th arise. The blower shoe of the process apparatus described above can then blow off the interiors to the left of the sheet plane 155 first alone when overflowing the open end of the filter 150, ie, its full blowing power is used to blow off the left half of the filter 150. After further rotation of the blower then the Area to be blown off to the right of the sheet plane 155. The peripheral contour of the filter 150 is oval again at the upper end.

In the embodiments illustrated in Figs. 13-16 and Figs. 18 and 19, when looking at a side edge, the support body widens from the bottom to the top in a V-shape as seen in Fig. 9 ,

Thus, in principle with the invention, all known supporting bodies or filter base forms can be produced.

The folded or corrugated sheets described above withstand enormous surface pressure even at sheet thicknesses below 1.0 mm. It may happen that a filter material placed around the support body is so heavily coated with particles that this causes a strong surface pressure on the zugebackene filter material and the underlying support body. It is in the process apparatuses with fan pressures of 10,000 Pa, which are about 1,000 kg / m <2>, worked. For a filter with a filter area of 0.5 m <2> that is still 250 kg pressure.

Claims (16)

1. Filter for dedusting process air (52) in a process apparatus (60), in particular in a fluidized bed apparatus, with a support body (11), on the outside of a textile cloth-shaped filter material (48, 116, 126) is laid, characterized in that the support body (11) is designed as a folded sheet (12, 92, 102, 152) around folding lines (20, 20), folds (153, 153) being on both sides of the original sheet plane (28, 96, 155) of the still unfolded sheet. 154), around which the cloth-shaped filter material (48, 116, 126) is laid. 2. Filter according to claim 1, characterized in that the outer ends of the folds (153, 154) of the folded sheet (12, 92, 102, 155) define an outer peripheral contour (40, 98, 142), the roughly rectangular, oval ( 40, 98) or circular (142) is formed. 3. Filter according to claim 1 or 2, characterized in that the cloth-shaped filter material (48, 116, 126) is placed under such a loose tension around the folds (153, 154) that through the filter material (48, 116, 126 ) passing through process air (52) this is partially hineinbewegbar between two adjacent folds (153, 154). 4. Filter according to one of claims 1 to 3, characterized in that seen over a fold line (20) of the supporting body (11) has a height (30, 30) of the folds (153, 154) is reduced. 5. Filter according to one of claims 1 to 4, characterized in that side edges (34, 36, 160, 162) of the folded sheet (11, 92, 102) are rounded. 6. Filter according to one of claims 1 to 5, characterized in that the surface (37, 38, 131, 131) of the folded sheet (12) is smooth. 7. Filter according to one of claims 1 to 6, characterized in that the folded sheet (12) at one end (58) with a closure flange (42) is provided. 8. Filter according to claim 7, characterized in that the folded sheet (12) is provided at the other end with a border frame (44). 9. Filter according to one of claims 1 to 8, characterized in that the folds are formed such that a rising and a falling edge (95, 97, 114, 157, 158) of a fold parallel to each other. 10. Filter according to claim 9, characterized in that the mutually parallel flanks (157, 158) abut each other. 11. Filter according to one of claims 1 to 10, characterized in that between two adjacent folds (153, 154) areas of the sheet are present, which extend in the original sheet metal plane (96, 155). 12. Filter according to one of claims 1 to 12, characterized in that the folds are wave-shaped (22, 26) are formed. 13. Process apparatus, in particular a fluidized bed apparatus, with a process chamber (65) in which a particulate material (70) is movable by means of process air (52), and with a filter device (76) arranged at the upper end of the process chamber (65), characterized in that the filter device (76) has at least one filter (10, 90, 110, 120, 130, 150) according to one of claims 1 to 12, wherein the filter (10, 90, 110, 120, 130, 150) is arranged in each case is that its fold lines (20, 20) run vertically in the process apparatus. 14. Process apparatus according to claim 13, characterized in that it has a device (80) for injecting cleaning air (88) into an interior (56) of the respective filter (10) via the filters (10, 90, 110, 120, 150). having. 15. Process apparatus according to claim 14, characterized in that a plurality of star-shaped juxtaposed depending filter (10, 10, 10) are arranged, over which a blower (82) of the device (80) passes, through each of which a filter ( 10) can be inflated with cleaning air while its nearest adjacent filter (10) can be covered. 16. Process apparatus according to claim 14 or 15, characterized in that extending the filters (10, 90, 110, 120, 150) with a non-circular peripheral contour with their longer cross-sectional axis along radii (67) of a circular process chamber (65).