EP2384235A1

EP2384235A1 - Filter apparatus for cleaning an emissions-laden gas and gas guiding element used therein

Info

Publication number: EP2384235A1
Application number: EP09803990A
Authority: EP
Inventors: Klaus Krüger
Original assignee: Kappa Filter Systems GmbH
Current assignee: Kappa Filter Systems GmbH
Priority date: 2008-12-22
Filing date: 2009-12-10
Publication date: 2011-11-09
Also published as: WO2010071907A1; AT506939A4; AT506939B1

Abstract

The invention relates to a filter apparatus (1) for cleaning an emissions-laden gas (7), comprising a hollow body (21) which separates a cavity (24) on the clean gas side from an outer space on the untreated gas side with a delimiting surface (11). At least one subsection of the delimiting surface (11) is formed by a gas-pervious filter element (12) for removing, for example, particulate emissions from a gas (7) which flows from the outer space through the filter element (12) into the cavity (24). In addition, at least one exit orifice (8) for removal of a filtered gas stream (9) from the cavity (24) is formed in the delimiting surface (11). In the flow path which leads from the filter element (12) to the exit orifice (8) is arranged at least one gas guiding element (2) with at least one guiding surface (5) akin to a screw surface, wherein one screw axis (6) of the guide surface (5) points in the direction of the exit orifice (8).

Description

Filter device for cleaning an emission-laden gas and this used gas guide

The invention relates to a filter device for cleaning an emission-laden gas, comprising a hollow body with a boundary surface a clean gas side cavity separates from a rohgassei tige outside, wherein at least a portion of the boundary surface, a gas-permeable filter element for separating, for example, particle-like emissions from an outdoor space by the filter element in the hollow space flowing gas, and at least one outlet opening in the boundary surface for discharging a filtered gas flow from the cavity comprises.

The field of application of such filter devices include the cleaning of particle-laden gas streams, in particular dust-laden air streams. Typical embodiments of such filter devices are, for example, as a cartridge filter or as

Bag filter known.

For this purpose, the filter device is mounted, for example, in a housing of a filter system or else on the outside or at a distal end of a flow channel for raw gases to be cleaned. The housing of a corresponding filter system is usually divided into two chambers, in particular a raw gas chamber and a clean gas chamber. The filter device, in particular its filter medium, is preferably arranged in the raw gas chamber, the particulate-laden air usually being conveyed by means of a vacuum generator, e.g. in the form of a suction fan or the like., Introduced into the raw gas chamber and passed through the filter element or its filter medium.

In constructive terms, such filter devices are often designed as a hollow body, in particular as a hollow cylinder, wherein the filter element or filter medium forms at least the shell portion of the filter device. The filter medium can be formed by a gas-permeable fabric or paper package, a gas-permeable fabric or textile element or by another element with filtering effect with respect to suspended particles or aerosols. Thus, the filter medium partially or wholly forms the outer boundary surfaces of the filter device and provides a filtering flow connection between the raw gas side and the clean gas side. The filter medium can be secured by at least one support element, in particular by an inner and / or outer support basket against unwanted Deviation movements or destruction due to the flow pressure or flow negative pressure. As the particulate laden gas stream flows through the filter media, at least some or a certain range of the emissions contained in the gas stream are separated from the gas stream in the form of solid and / or liquid particles. A comparatively pure gas stream then leaves the filter device via its outlet opening and can then flow into the clean gas chamber or escape directly into the immediate environment.

In such filter devices, the filter surface, in particular the inlet surface for the raw gas in the filter medium, often a multiple of the existing or available exit area, ie the clear cross section of the outlet opening for the clean gas from the filter device. The raw gas, which is supplied to the gas-permeable filter element or flows through it, is undirected. In the cavity of the filter device forms a localized, turbulent gas flow, inter alia due to the spatial boundary through the filter medium and due to the inflow of raw or clean gas from a variety of different directions and positions. Characteristic of turbulent gas flows are many small individual vortices, which can increase the flow resistance of the filter device. These flow vortices usually form directly on the inner boundary surface or in the cavity of the filter element and have an increased flow resistance result. This increased flow resistance must either be compensated for again via an increased power consumption of the underpressure or overpressure generators, or the throughput or filter performance of the filter element is impaired while the flow or negative pressure remains the same.

The object of the invention is now to reduce the flow resistance of a filter device and to improve the efficiency of a generic filter device or a filter system equipped therewith.

This object of the invention is achieved by a filter device with the features of claim 1, or by a gas guide element according to claim 19. Due to the inventive design and arrangement of a schraubflächen- or helical guide surface comprehensive gas conducting element, which faces towards the outlet opening of the filter device or at least partially extends in the cavity, an advantageous reduction of the flow resistance with respect to the passage or exit of the Gas achievable. In particular, the clean gas in the cavity of the filter device is at least partially directed or relatively uniformly aligned, so that the clean gas with respect to the relatively narrow outlet opening smoothly or purposefully emerge from the cavity or can escape.

By means of the gas guide element, the gas flow is at least partially a Drallbzw. Spiral movement deliberately forced, so to speak creates a controlled gas vortex. In particular, uncontrolled running currents or chaotic eddies in the cavity are largely suppressed or reduced and can amplify or form a directed flow comparatively faster.

In particular, the turbulent flows or gas vortices are reduced in the interior of the filter device or they are less pronounced by the use of the specified gas guide element, resulting in a reduction of the flow resistance. This is mainly due to the generated by the gas guide element drallr or spirally extending clean gas flow. As a result, either an increased gas throughput can be achieved with the same power of the underpressure or overpressure generator or an equally high gas throughput with reduced power of the underpressure or overpressure generator. Due to the increased throughput at the same electrical drive power existing filter systems can achieve a higher filter performance and a better filter performance.

Furthermore, significant savings in the design of the electric drives and in the energy costs for ongoing operation can be achieved by the constant gas flow volume with lower, required drive power or operating energy. Especially in large-scale systems with high energy requirements, there is an increased energy-saving potential. In addition, even with existing filter systems, which are retrofitted or equipped with the filter devices according to the invention, a better utilization, in particular a higher efficiency, can be achieved. In any case, it is also possible to use it with existing systems without any problems, since after retrofitting the recorded gas conducting the above-described, advantageous effects can be achieved without having to expand or rebuild an existing filter system with great financial cost. After such conversions can also be implemented relatively quickly, a costly or longer-lasting shutdown of production or processing plants is hardly required.

Due to the configuration according to claim 2, the hollow body has a fluidic and manufacturing technology favorable form. In addition, this largely avoids local aggregation of separated particles or achieves the most uniform possible distribution over the entire available filter area.

Due to the configuration according to claim 3, a relatively intensive rectification or unification of the flow direction of a prevailing in the cavity of the filter device gas flow can be achieved.

The gas guide element can develop its optimizing effect with respect to the flow behavior or the flow resistance especially in the presence of structural conditions according to claim 4.

Due to the configuration according to claim 5, a simple production of the gas-conducting element is made possible, whereby the costs for the implementation of the gas-conducting element can be kept as low as possible.

Also advantageous are the measures according to claim 6, according to which the gas guide element has a plurality of guide surfaces for gas guidance. As a result, among other things, the individual forces can be reduced to the respective fins. In addition, this creates a plurality of substantially parallel, spiral flow channels, each with a relatively small flow cross section, whereby a better alignment or homogenization of the gas flow can be established.

Due to the configuration in claim 7 can be made a contacting of the guide surfaces on the boundary surfaces, whereby the guide surfaces of the gas guide a higher stability can be imparted. Due to the embodiment according to claim 8, the gas guide can be optimally adapted to different degrees of density and flow rates of the gases to be filtered and thus the gas line can be optimized depending on the particular parameter present.

According to the measures according to claim 9, a cavity or flow channel is formed along the screw axis, which is particularly for cleaning mechanisms or cleaning work, for visual checks of the filter medium for maintenance activities and / or for the installation of the gas guide advantageous. For example, the introduction of cleaning compressed air into the interior of the filter device can thereby be simplified or made more efficient. Furthermore, a flow channel is thereby formed in the center of the filter device or along the screw axis of the gas guide element, which can also provide fluidic advantages.

Due to the configuration of the gas guide element according to claim 10, a plurality, at least spatially separated, but not necessarily gas-tight separated from each other Gasleitkanäle can be constructed in which each gas flows are guided or aligned.

The slope of the baffles according to claim 1 1 offset the filtered gas flow in the cavity of the filter device in the desired swirl or spiral movement, whereby the flow-optimizing properties of the gas guide are effected. The slope of the fins, i. The angle of rotation or the number of full revolutions of the gas guide surface with respect to the screw axis can have different, respectively favorable values depending on the flow velocity, density of the filtered gases and the volume of the gas flow. In particular, the shape of the guide surfaces or the design of the gas-conducting element is dependent on parameters of the gas and on the constructional conditions or dimensions of the filter device in order to achieve the most optimal swirl or spiral movement of the clean gas.

By the measures according to claim 12, the number of revolutions of the gas stream in relation to the screw axis of the gas guide element in a simple manner can be adapted to the respective requirements or conditions. With a higher pitch angle while the number of revolutions of the guide surface is about the screw axis of the gas guide less, whereby the flow resistance is kept low. With a low lead angle, a higher number of guide elements or a larger area guide surface can be formed, whereby although the degree of homogenization in the gas stream increases, but the flow resistance is increased.

The embodiment according to claim 13 ensures that the gas flow prevailing in the interior of the filter device during filter operation flows as laminarly as possible. In particular, as a result of the passage of the gas flow through the filter medium or upon the entry of gas flows into the cavity of the filter device, forcibly occurring flow turbulences are as far as possible avoided or at least shortly before leaving the filter device converted into a comparatively laminar or directed flow.

In the embodiment according to claim 14, it is advantageous that the filter medium, in particular a so-called filter cartridge or a filter sock, is replaced in a simple manner when the maximum duration of use is reached, and the substantially maintenance-free gas guide element can continue to be used. As a result, the lowest possible operating and maintenance costs can be achieved. In addition, the most intensive or thorough cleaning of the filter medium, for example using compressed air, can be achieved after the filter medium, starting from the inner surface facing the cavity, can be subjected to as full as possible pressurization or cleaning.

Another advantage is also an embodiment according to claim 15, characterized in that the gas guide element is designed in the manner of a mounting or mounting adapter to which standard available filter elements attached and can be easily removed if necessary by a preferably stationary admonished adapter, for example, cleaning To carry out exchange or other maintenance work simply and at short notice. The mechanical connecting elements are formed by coupling members, in particular by extensions or recesses, which are displaceable with corresponding coupling members on the filter element or filter medium in and out of form-fitting connection. The measure according to claim 16 allows a simple and cost-optimized production of the gas guide element and the most economical use of the specified filter device.

In the embodiment according to claim 17, it is advantageous that the gas guide element also assumes the function of a support body for the filter medium. This is an essential criterion for a high efficiency of the corresponding filter device, especially in the case of so-called bag filter systems with a shape-flexible or relatively unstable, bag or stocking-like filter element or filter medium. In particular, the outer edges of the guide surfaces of the gas guide take over a support function, so far usual support baskets with lattice-like structures can be made unnecessary. This means that the stated gas guide on the one hand supports the flexible, mostly bag-like filter medium, whereby the desired shape stability or hollow body shape of the filter sock or filter bag is ensured, and on the other hand causes an improved or flow-optimized discharge or forwarding of the clean gas from the filter sock becomes.

Also, by the design according to claim 18 can be achieved, a flow-optimizing function, since here is after the outlet of the filter apparatus, a gas guide element ^"formed, whereby a direct conversion of the directed flow in a turbulent flow can be kept disregard. In particular, extending thereby the arranged inside or an additional gas guide beyond the outlet opening to maintain the at least partially directed gas flow even after the Austrittsöffhung from the filter element within a certain transition section upright.

The object of the invention is also achieved by the measures according to claim 19.

An advantage resulting from the features in claim 19 lies in the fact that the gas-conducting element can be used in a simple manner even with existing filter devices. In particular, already existing filter systems can be retrofitted with a gas guide, without requiring extensive conversion work on the respective filter systems. As a result, existing systems can achieve a higher filter performance and better efficiency. On the other hand, the filter performance or the volume flow can essentially be maintained, however, can be achieved by the Gasleit- a reduction in the required drive energy, in particular the electrical energy consumption of the underpressure or overpressure generator can be achieved.

Similarly, in an internal combustion engine, which is equipped in the intake passage for the combustion air with the designated filter device or provided with the specified gas guide, the efficiency improved or the available output power can be increased. The installation of the gas guide requires no significant structural change to the filter system or on the intake.

In industrial filtration systems, a conversion or adaptation can usually be done in conjunction with the usual maintenance activities. Especially when the filter system has several filter units working in parallel, the respective filter or production plant can continue to operate without shutdown. A production operation is thus not or only slightly impaired by the implementation of gas guide elements according to the invention. Costly shutdowns of production lines are therefore not absolutely necessary.

An embodiment according to claim 20 is particularly advantageous because it provides a device in the manner of a mounting or fastening adapter for a cartridge-like filter element, for example, with respect to the gas-conducting element. By sufficiently sealing or tailor-made as possible connecting and sealing surfaces on the gas guide element or on its base body, the standard filter holder or coupling mechanism on a conventional filter element in an advantageous manner continue to be used. Such a design is possible on the one hand with relatively small cartridge filters for use in internal combustion engines, as well as filter systems in the household sector and industrial large filter systems.

An advantage resulting from the measures of claim 21 lies in the fact that the gas-conducting element or the filter element can be installed or dismantled with simple manipulations relatively quickly and preferably without the aid of tools. This is particularly practical or efficient in the field of application of automotive technology and small filter systems. For a better understanding of the invention, this will be explained in more detail with reference to the following figures.

In each case, in a highly simplified, schematic representation:

Figure 1 is a perspective view of a filter device with partially cut filter element and integrated gas guide.

2 shows a filter device with a filter element cut along the longitudinal axis with different embodiments of a gas-conducting element;

FIG. 3 shows the filter device according to FIG. 2, cut along lines III-III in FIG. 2;

4 shows a filter device in longitudinal section with a multiple gas guide element for forming a plurality of largely separate gas guide channels.

FIG. 5 shows the filter device according to FIG. 4, cut along lines V-V in FIG. 4; FIG.

6 shows a filter device in longitudinal section with a gas guide element which has a recess or free position about the longitudinal axis or screw axis;

FIG. 7 shows the filter device according to FIG. 6, cut along the lines VII-VII in FIG. 6; FIG.

8 shows a filter device with a different diameter gas guide element and a plurality of guide surfaces in the end portion of the filter device opposite the outlet opening;

9 shows a gas-conducting element in conjunction with a filter device designed as a hose filter, wherein the gas-conducting element also fulfills the function of a supporting body for a form-flexible, bag-like filter sock; 10 shows a gas-conducting element in combination with a fastening adapter for interchangeable mounting of a filter device, the gas-conducting element having in this exemplary embodiment vaπierende Anstellbzw pitch angle of the guide surfaces with respect to the screw or longitudinal axis.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component designations, wherein the disclosures contained in the entire description can be mutatis mutandis to the same parts with the same reference numerals or the same Bautet Ibezeichnungen transmitted. Also, the position information selected in the description, such as, for example, top, bottom, side, etc. related to the immediately described and illustrated figure and are these position information in a change in position mutatis mutandis to transfer to the new location. Furthermore, individual features or combinations of characteristic cornmeat from the different exemplary embodiments shown and described can also represent separate, inventive or inventive solutions.

All statements on ranges of values in the description of the present invention should be understood to include any and all sub-ranges thereof, e.g. the indication 1 to 10 should be understood to include all sub-ranges, starting from the lower limit 1 and the upper limit 10, i. all sections start with a lower one

Limit of 1 or greater and terminate at an upper limit of 10 or less, eg, 1 to 1, 7, or 3.2 to 8, 1, or 5.5 to 10.

In Fig. 1, an embodiment of a Filtervornchtung 1, in particular a so-called cartridge filter, in combination with a gas guide 2 illustrated. According to this embodiment, the gas guide 2 extends at least approximately over the entire length 3 of the Filtervornchtung 1 or over the entire axial length of the inner cavity in the Filtervornchtung 1. The gas guide 2 is formed by a developable screw 4, which is a schraubflächenförmige or coiled Guide surface 5 for gas or air flows inside the Filtervornchtung 1 forms. The guide surface 5 extends spirally around the longitudinal axis of the Filtervornchtung 1 In particular, a screw axis 6 is defined, around which the guide surface 5 spirally or helically winds. The gas guide element 2 with its schaufei- or screw-surface-like guide surfaces 5 forces a prevailing in the cavity of the filter device 1 flow to a spiral or spiral movement. In particular, a raw gas or gas 7 to be filtered, for example air, is fed to the filter device 1 from the outside and passed or sucked via the filter medium into the inner cavity of the filter device 1. In the inner cavity of the filter device 1, the gas flow 9 undergoes, at least in part, a swirl or spiral movement by means of the gas guide element 2 before the gas flow 9 is discharged or removed from the cavity via the outlet opening 8. As a result, the turbulent flow usually occurring in the filter cavity is aligned or tends to be unified. This results in a lower flow resistance or in a reduced energy requirement for a

Overpressure or vacuum generator in the flow path of the untreated gas 7 or of the filtered gas flow 9.

As a result of a lower flow resistance of the filter device 1, the required drive energy is reduced in the case of an electrically driven vacuum generator, for example.

On the other hand, due to the lower flow resistance with the same expenditure of energy, a higher gas throughput or a higher volume flow can be achieved by the filter device 1. In the case of newly designed systems, it is possible to select drives with comparatively low power values, in particular less powerful and therefore smaller electric drive motors. As a result, the construction costs and also the ongoing operating costs of filter systems which are equipped with the specified filter devices 1 or gas guide elements 2 can be lowered.

In the embodiment according to FIG. 1, outer boundary edges or outer edges 10 of the guide surfaces 5 lie at least in sections, but preferably at the inside

Limiting surfaces of the gas-permeable filter element 12, whereby two largely separate gas ducts 13, 13 'are formed, in which largely independent gas streams 9 can form.

The filter device 1 comprises in the embodiment shown a hollow cylindrical

Filter element 12, wherein the screw axis 6 of the gas guide element 2 is aligned in alignment with the longitudinal axis of the filter element 12. At a first axial end of this hollow cylindrical filter device 1, the outlet opening 8 is formed, while the second axial end of the filter device 1 is either gas-tight closed, or analogous to the lateral surface of the filter device 1 has a gas-permeable filter medium.

However, the filter element 12 may also be designed conical or frusto-conical. With respect to a right angle to the longitudinal axis or screw axis 6, the filter element 12 may have a circular or oval cross-sectional contour.

2, 3 show a filter device 1, in particular a cartridge filter with an at least partially disposed in the inner cavity gas guide 2. According to a first embodiment, a gas guide 2 is provided with a relatively small diameter, as indicated by solid lines. In particular, an outer diameter 14 of the gas-conducting element 2 can amount to between approximately 40% and less than 100%, expediently approximately 66% of an inner diameter or a clear width of the filter element 12. According to an alternative, second embodiment, the gas guide element 2 extends with respect to its outer diameter 14 over the entire inner diameter, i. over 100% of the inner or cavity of the filter element 12, as indicated by dashed lines.

According to a further embodiment, the gas guide element 2 projects beyond the inner cavity or via the outlet opening 8 of the filter device 1, as shown in solid lines. According to the embodiment variant shown in dashed lines, the gas guide element 2 extends with respect to the longitudinal or screw axis 6 exclusively within the cavity of the filter device 1.

In this case, the outer diameter 14 of the gas-conducting element 2 can be smaller than a clear cross-sectional width or a diameter 15 of the outlet opening 8 in accordance with a first embodiment variant. This makes it possible to make the gas-conducting element 2 interchangeable or reusable. So that the gas-conducting element 2 can fulfill its intended function, it is held in a rotationally fixed manner in relation to the filter device 1 or its filter element 12. This holder can be carried out in various ways, in particular be implemented by a mechanical coupling and / or screw 16. A partial Component of this coupling and / or screw 16 is formed on the gas guide 2 to connect the gas-conducting element 2 by a coupling or screwing firmly with the arranged on or in the filter element 12 counterpart and optionally be able to solve it again. A Verschraubungsrichrung a screw is suitably chosen counter to the twist direction or Wendelungsrichrung the gas stream 9, so that the screw connection can not be solved by the force exerted on the guide surfaces 5 rotational forces.

According to an alternative embodiment, a plug-in or clamping connection 16 'is formed between the gas-conducting element 2 and the filter element 12, as was illustrated in FIG. 2 by dashed lines. In this case, the gas guide element 2 is inserted by means of an extension into a corresponding, precisely fitting groove or with a recess in a corresponding, precisely fitting extension by clamping. These mutually corresponding coupling or clamping elements can be formed on one end face of the gas guide diaphragm 12 and on one of the outlet opening 8 opposite boundary wall of the filter element 12. The correspondingly constructed clamping force should be greater than the force acting on the gas guide element 2 in the direction of the outlet opening 8 via the gas flow 9 in order to hold the gas guide element 2 in the respective desired position.

As further illustrated by way of example in FIG. 2, the end or boundary wall opposite the outlet opening 8 can also be designed as a filter element 12 or have a filter medium. In order to give the filter element 12 more stability, it is possible to assign the filter element 12 or the actual filter medium at least partially support elements, for example in the form of hollow cylindrical expanded metal elements, grid mats or support baskets. The gas-conducting element 2 can also be supported by at least one spacer 17, which is arranged in the interior of the filter device 1 and connected in a load-transmitting manner to the gas-conducting element 2. This at least one spacer 17 may be formed of a flexible material, which has a sufficiently high flexibility to deform so elastically when removing the gas guide element 2 via the outlet opening 8, that the gas guide 2 via the outlet opening 8 relatively easily from the Filter element 12 can be removed. However, other methods which permit non-destructive removal or assembly of the gas allow guide element 2 against a worn or heavily contaminated filter element 12, are applied.

According to the advantageous embodiment variant, in which the gas guide element 2 protrudes beyond the outlet opening 8, a laminar gas flow 9 which is as laminar as possible is also achieved in the immediate transitional section between the outlet opening 8 and an adjoining collecting or drainage channel. In particular, this at least partially maintaining the fluidically advantageous, directed gas flow 9 is achieved, which would otherwise relatively quickly lose its advantageous orientation and would soon revert to a relatively turbulent flow through the abrupt end of the gas guide 2 and the filter element 12.

According to the embodiment variant shown in dashed lines in FIGS. 2, 3, the gas-conducting element 2 is held in a rotationally fixed manner with the outer edges 10 of the guide surfaces 5 relative to the inner surfaces or the inner boundary surfaces of the gas-permeable filter element 12. As a result, the gas guide channels 13, 13 'already described in FIG. 1 are formed, which result in largely separated, spiral or spiral gas streams 9. In this variant, the gas-conducting element 2 is not configured over the entire length of the filter device 1, but ends the gas-conducting element 2 in this embodiment at a distance 18 in front of the outlet opening 8. This gives the purified gas streams 9 the possibility of being at a distance 18 form shortly before the outlet opening 8 as a common, spiral or helical gas flow 9 and the outlet opening 8 collected to pass.

The guide surfaces 5 of the gas-conducting element 2 can be formed, inter alia, with regard to the respective gas streams 7 to be conducted by many different materials. In particular, the gas-conducting element 2 can be formed from materials which, depending on the conditions of use, have an increased temperature and / or acid resistance. According to an advantageous embodiment, the gas-conducting element 2 or its guide surface 5 is made of an extrudable material, such as plastic. Alternatively, the gas-conducting element 2 can also be produced in an injection molding process for processing plastics or metallic materials. This is in terms of variable slopes of the guide surfaces 5 and / or a Mehrgängigkeit the gas guide 2 a fast to be realized, well reproducible and On the other hand, an advantage of an extrusion process is that in a short time a large amount of gas guide elements 2 can be manufactured as rod goods and each require designs or lengths by simply cutting the bar products according to the respective Erfor - can be created.

However, the at least one curved guide surface 5 of the gas-conducting element 2 or the gas-conducting element 2 per se can also be produced by other methods, in particular by twisting, pressing, stamping, casting, sintering or the like.

According to an advantageous, as easy to manufacture embodiment, the gas guide element 2 is formed with its spiral-like guide surfaces 5 by a strip-shaped plate member, wherein at least one of the distal ends of the plate member is rotated or twisted about the longitudinal or central longitudinal axis and the strip-shaped plate member therethrough is turned into a spiral or permanently converted into a spiral shape.

The application of an injection molding method allows in a simple manner a multi-part design of the gas guide element 2, wherein individual sections are assembled via plug, screw and / or adhesive connections to a one-piece gas guide element 2. In particular, relatively short, injection-molded items by conventional connection methods, such as gluing, welding, screwing, plugging or tool-free mounting types, are joined together to form a multi-part, one-piece gas-conducting element 2. Production-technically advantageous materials for the gas-conducting element 2, such as plastics, can hardly meet the mechanical and / or chemical requirements occasionally. Such materials can be rendered more resistant or suitable by a coating 19 with other materials which are applied, for example, in a galvanizing, anodizing, powder coating or painting process. Thus, it is possible to provide a favorable base material with a relatively resistant coating 19. The coating 19 on the gas-conducting element 2 can also be formed by a nano-coating or nano-structuring in order to achieve easy cleaning or a lower susceptibility to soiling. Furthermore, it may be advantageous to chemically treat the gas 7 or the purified gas stream 9 already in the filter device 1 with the aid of catalysts. For this purpose, the gas-conducting element 2 can consist of corresponding materials for such a catalytic process or be coated therewith. It is expedient to perform the guide surfaces 5 of the gas guide element 2 is not gas-tight, but to give the guide surfaces 5 a certain diffusion possibility for certain gases or molecules. The material of the guide surfaces 5 of the gas guide element 2 has microscopically small openings 20 in order to allow such diffusion. The corresponding guide surfaces 5 or gas guide elements 2 can be made wholly or only in sections of membrane-like or vapor-permeable materials.

To provide the filter device 1 with an inner cavity, in particular to form a hollow body 21, is particularly useful with regard to the filter performance. The filter device 1 or its filter element 12 in cross-section at least approximately circular, in particular to carry out hollow cylindrical, structurally and fluidically advantageous. The cross-sectional shape of the hollow body 21 may also be selected oval or elliptical. As a result of the at least approximately circular cross section, no or as few edges and / or projections as possible are present on the inner and outer boundary surfaces 11 of the hollow body 21, so that turbulent turbulences are avoided as far as possible. This results in a more homogeneous gas flow 9 or as laminar flow as possible and a relatively lower flow resistance. In addition, by a minimized in terms of edge or corner shape a local accumulation of deposited particles held back and favors the most evenly distributed use of the filter medium. The formation of a controlled swirl or spiral flow in the gas stream to be diverted is also promoted by the at least approximately circular, internal cross-section of the filter element 12 in combination with the helical or spiral-shaped gas guiding element 2.

FIG. 3 shows a sectional view of the filter device 1 according to FIG. 2 corresponding to the sectional lines III-III in FIG. 2. The embodiments of the gas-conducting elements 2 described above are illustrated on the one hand in solid lines and on the other hand in dashed lines. By this sectional view of the filter device 1, the positioning and configuration of the gas guide element 2 and the formation of the corresponding guide surfaces 5 is clear seen. The cutting axis was chosen so that the previously described Steckbzw. Clamping connection 16 ', which serves for the rotationally fixed mounting or simple mounting of the gas-conducting element 2 within the filter element 12, is once again shown diagrammatically. In this case, the end face of the gas conduction element 2 opposite the outlet opening 8 is held in a receiving groove. Also, via the guide surfaces 5 of the gas guide 2 largely separated gas guide channels 13, 13 'in the hollow body 21 of the filter device 1 are clear from this.

FIGS. 4, 5 show a further embodiment of a gas-conducting element 2 within the hollow body 21 of the filter device 1. In this case, the gas guide element 2 is designed to be four-shaped. In particular, the guide surfaces 5 of the gas-conducting element 2, in conjunction with the inner boundary walls of the hollow body 21, subdivide the inner cavity 24 of the filter element 12 into four parallel gas guide channels 13-13 '' 'according to example. The gas guide element 2 lies with its outer edges 10 against the inner boundary surfaces of the Thus, for example, four essentially separate gas ducts 13-13 '"which due to the gas-permeable filter element 12 and due to missing or barely expedient seals between the outer edges 10 and the inner boundary surfaces of the hollow body 21 only spatially separated from each other - are. A positionally stable mounting of the gas-conducting element 2 is achieved by the contact points of the outer edges 10 of the guide surfaces 5 with the inner boundary surfaces of the filter element 12. The gas guide element 2 thus also forms an inner support body for the filter element 12 or for its filter medium. Separate support baskets, which are often formed from a hollow cylindrical expanded metal body, can thus be saved. In particular, in this embodiment, the gas-conducting element 2 advantageously also assumes a supporting function for a frequently relatively unstable filter element 12, which may be formed, for example, from folded or multilayered filter paper. If appropriate, the gas-conducting element 2 can also be adhesively bonded or welded to the filter element 12 at individual contact points.

A two- or multi-channel embodiment of the gas-conducting element 2 can also be advantageous, in particular, if, due to the size or diameter of the filter device 1 and / or due to the speed and / or density of the gas 7 to be filtered practicable spiral or spiral flow only then forms when the volume of the individual gas streams 9 and Gasleitkanäle 13-13 '"is reduced accordingly.

According to an embodiment, as can also be seen from FIG. 4, the gas-conducting element 2 can be located at a distance 22 in front of an end opening 8 opposite the outlet opening 8. Limit wall of the filter element 12 ends or begin. The gas-conducting element 2 thus does not extend as far as the end wall or boundary wall of the filter element 12 which is closed in a gas-tight manner or with a filter medium. In particular, the gas-conducting element 2 is predominantly associated with the outlet opening 8 in order to achieve a lamellar gas flow or an as-ordered one as possible To achieve flow outlet. The formation of a gas guide element 2 in the end opening 8 facing away from the end portion of the filter element 12 is therefore not absolutely necessary. Among other things, this cost and weight savings are possible. In particular, the gas-conducting element 2 can be positioned near the outlet opening 8 and extend in about 2 to 90%, in particular 5 to 50%, preferably 3 to 33% of the axial length 3 of the filter element 12 or its cavity 24.

Alternatively, it is also possible to arrange the gas guide element 2 at an axial distance from the outlet opening 8. Furthermore, it is possible to distance the gas-conducting element 2 with respect to the outlet opening 8 and with respect to the boundary wall of the filter element 12 opposite thereto.

FIGS. 6, 7 show a further embodiment of a gas-conducting element 2 with screw-shaped or helically extending guide surfaces 5. In this embodiment variant of the gas guide element 2, the guide surfaces 5 are recessed along the screw axis 6 or at least one axially extending aperture in the gas guide element 2 is formed around the screw axis 6. This means that inner boundary edges of the guide surfaces 5 and of the gas guide element 2 run at a radial distance 23 to the longitudinal or screw axis 6 of the gas guide element 2, so that along the screw axis 6, a preferably continuously extending or partially formed, centrally positioned flow channel results. A gas 7 entering the cavity 24 via the filter element 12 is directly aligned by the guide surfaces 5 of the gas-conducting element 2 formed on the inner boundary surface of the filter element 12 in order to prevent turbulent flows or turbulence. prevent or minimize it as early as possible. In the preferably longitudinally or axially extending flow channel or cavity of the gas guide element 2, a gas stream 9 can then form which is guided by the outer guide surfaces 5 of the gas guide element 2 radially spaced from the screw axis 6. This refinement with guide surfaces 5 extending peripherally to the screw axis 6 can be advantageous, above all, in the case of relatively high volume flows or voluminous gas flows 9 in the region in front of the outlet opening 8. In particular, if the desired swirl or spiral flow is already sufficiently pronounced in a section shortly before the outlet opening 8, an overly large-area guide surface 5 would only cause an increased flow resistance.

The guide surfaces 5 of the gas guide element 2 should therefore be made as small as possible with a view to minimizing the flow resistance. For this purpose, the outer diameter of the gas-conducting element 2 can be made smaller than the inner, clear diameter of the filter element 12, as illustrated in FIG. 2. Alternatively or in combination therewith, a central release or a breakthrough running at least in sections along the screw axis 6 can be carried out, as was illustrated in FIG.

The formation of a central exemption or a longitudinally extending flow channel in the gas-conducting element 2 is also advantageous for filter devices 1 or filter systems in which a cleaning device is used which operates with compressed-air pulses. These compressed air pulses are generated in the interior of the filter element 12. In particular, there is an action of compressed air with respect to the inner boundary surfaces of the filter element 12, so that at the outer B egrenzungs surface 1 1 of the filter dement 12 optionally liable gas deposits or particles are repelled as fully as possible. These cleaning devices thus often clean the filter element 12 with targeted compressed air pulses, which are conducted into the cavity 24. A centrally or centrally released gas-conducting element 2, as described above, permits a simple introduction of such compressed-air flows into the cavity 24 and the highest possible effectiveness with respect to the filter element 12. In particular, an increased efficiency is achieved after pressure losses are largely avoided. In addition, the filter element 12 can be better viewed through the central or axially parallel cavity in the gas guide 2 with respect to maintenance. In particular, a simpler, visual inspection of the inner boundary surfaces in terms of any damage or heavy soiling is possible. The fastening of the gas-conducting element 2 within the filter element 12 or the filter device 1 to a corresponding mounting or holding flange can also be carried out via the central cavity in the gas-conducting element 2 in a simple and practical manner. In addition, any coupling and / or screw connections can be easily achieved with appropriate tools.

In Fig. 8, the embodiment of a single gas guide element 2 or more juxtaposed gas guide elements 2, 2 'with varying or different diameters 25 and 25' is illustrated. For certain compositions of the gases to be filtered 7 and / or at certain lengths of the filter device 1 and / or at certain flow velocities and / or gas volumes, it may be expedient to adapt the geometric design of the gas-conducting element 2 multiple times within a filter device 1. In Fig. 8 some combination or variation possibilities with respect to the diameter 25 of the gas guide element 2 are shown by way of example.

The gas guide 2 may be conically tapered or conical or frusto-conical in side view, wherein the tapered in diameter 25, axial end portion of this conical gas guide element 2 of the outlet opening 8 may be assigned or facing, as shown in Fig. 8 by way of example , Alternatively, it is also possible to assign the comparatively narrow, axial end section of the screw-shaped gas-conducting element 2 to the end of the filter element 12 opposite the outlet opening 8, and the second end section of the conical gas-conducting element 2, which has a relatively large diameter 25, near the outlet opening 8 provided.

Further, in the end portion of the filter element 12 opposite the outlet opening 8, the gas flow 9 can be shaped or uniformly aligned by a multi-passage gas guide element 2 '. In this case, the gas stream 9, which is relatively small in relation to the volume flow, is replaced by a plurality of gas guide channels 13, 13 ', a sufficiently pronounced swirl or spiral motion. imposed. In the outlet opening 8 facing the end portion of the diameter 25 of the multi-gas conducting element 2 is relatively small compared to the diameter of the gas guide element 2 in the region of the opposite end portion. As a result, the gas stream 9, which widens or expands in the direction of the outlet opening 8, can flow out relatively freely through the outlet opening 8.

For the sake of completeness, it should be noted that these embodiments relate not only to the cone-shaped gas guide element 2 described in FIG. 8, but such a conical shape can also be used in the embodiments of the gas guide element 2 according to FIG. In particular, a hollow conical gas guide element 2 may be formed, wherein the recess along the screw axis 6 is hollow-conical or the central flow channel in the gas guide element 2 has a conical shape.

9 shows the embodiment of a gas-conducting element 2, in which the gas-conducting element 2 additionally fulfills the function of a supporting element, as is the case with the use of so-called

Bag filters or filter devices 1 with flexible, stocking or bag-like filter media is expedient.

When forming filter devices 1 with a flexible or inherently unstable filter material 26, it is necessary to provide an inner support element in order to ensure a hollow-body-like shape of the filter medium 26 during the intended use of this filter device 1. Otherwise, the formflexible filter material 26 would not maintain its hollow body-like shape when pressurized via the gas 7. It is essential that the gas-conducting element 2 inserted into the bag-shaped filter material 26, as exemplified in FIG. 8, also fulfills the function of a support element for the flexible filter material 26. In particular, the hitherto customary lattice-type support baskets in so-called bag filters can be replaced in a simple manner by a gas guide element 2 supporting the filter sock or the filter material 26 in accordance with at least one embodiment described herein.

The flexible filter material 26 can wrap the gas guide 2 relatively loosely, so that it does not abut the outer edges 10 of the guide surfaces 5 of the gas guide 2 in the inactive or pressureless state of the filter device 1, as shown in Fig. 9 with dashed lines was presented. As soon as the filter device 1 is supplied with a gas 7 to be cleaned by means of a suitable overpressure or underpressure generator, not shown, the flexible filter material 26 abuts the outer edges 10 of the guide surfaces 5 in sections. These outer edges 10 thus provide the shape or outline contours of the flexible filter material 26. In this case, the gas-conducting element 2 can completely or even partially replace a conventional support basket with respect to various parameters of the gases 7 to be filtered, such as, for example, flow velocity or throughput volume.

Here, too, a purified gas stream 9 entering the interior of the sack-like filter medium 26 can be diverted as much as possible from the outlet opening 8 by means of the gas-conducting element 2, which represents a fluidic bottleneck, as it were.

FIG. 10 shows a gas-conducting element 2, which at the same time represents or forms a holding or mounting adapter for filter elements 12. In particular, at least one connection and / or sealing surface 28 for a cartridge-like filter element 12, for example, is formed on a support body 27 of the gas-conducting element 2. The gas guide element 2 is screw-shaped or helical in accordance with the preceding descriptions and has at least one guide surface 5 wound around a screw axis 6. In particular, this gas-conducting element 2 also comprises a support body 27 with adequate connection and / or sealing surfaces 28. These connection and / or sealing surfaces 28 make it possible to insert the gas-conducting element 2 into standard filter elements 12, as shown in FIG. lated lines.

A geometrically corresponding filter element 12 can by a standard

Plug, KJemm- and / or screw connection with the support body 27 of the gas guide element 2 are coupled.

FIG. 10 also shows an embodiment of the gas-conducting element 2 or its guide surfaces 5 with different or varying angles of inclination 29. The pitch angle 29 is a measure of the number of slopes of the gas guide element 2 per unit length. A high pitch angle 29 means that within a certain unit of length only a relatively small number of pitches are provided, with a low pitch angle 29 allows a relatively high number of slopes or turns. As shown in FIG. 10, a low-voluminous gas flow 9 can be forced into a sufficient swirl or spiral flow in the section facing away from the outlet opening 8 due to a low pitch angle 29. An unchanged low pitch angle 29 could obstruct the increasing in terms of volume and / or speed gas flow 9 in its throughput when approaching the outlet opening 8. Accordingly, it may be advantageous to increase the pitch angle 29 in the vicinity of the outlet opening in order to oppose the gas flow 9 only with a low flow resistance. In addition, the desired swirl or spiral flow is already largely formed in this section. The guide surfaces 5 may have a constant or varying pitch angle 27 from a range with a lower limit of 10 °, in particular 20 °, preferably 35 °, and an upper limit of 80 °, in particular 70 °, preferably 55 °.

The respective effects of the gas-conducting element 2 can thus also be used with existing filter devices 1 or filter systems. The support body 27 is designed in the manner of a holding or mounting adapter, so that existing filter systems can be easily retrofitted.

The embodiments show possible embodiments of the filter device 1 and the gas guide 2, it being noted at this point that the invention is not limited to the specifically illustrated embodiments, but rather various combinations of the individual embodiments are possible with each other and this variation possibility due to the teaching for technical action by objective invention in the skill of those working in this technical field. So are all conceivable embodiments, which are possible by combinations of individual details of the illustrated and described embodiments, of the scope of protection. For the sake of order, it should finally be pointed out that for a better understanding of the construction of the filter device 1 or the gas-conducting element 2, these or their components were shown partially unevenly and / or enlarged and / or reduced in size. The task underlying the independent inventive solutions can be taken from the description.

Above all, the individual in Figs. 1; 2, 3; 4, 5; 6, 7; 8th; 9; 10 embodiments form the subject of independent, inventive solutions. The relevant objects and solutions according to the invention can be found in the detailed descriptions of these figures.

REFERENCE NUMBERS

1 filter device 2 gas guide

3 length

4 screw surface

5 guide surface 6 screw axis

7 gas

8 outlet opening

9 gas flow

10 outside edge

11 boundary surface

12 filter element, 13 'Gasleitkanal

14 outer diameter 15 diameter

16 coupling and / or screw connection

16 'plug and / or clamp connection 17 spacers

18 distance

19 coating

20 opening 21 hollow body

22 distance

23 distance

24 cavity

25 diameters

26 filter material

27 supporting body

28 connection and / or sealing surface

29 pitch angle

Claims

Patent claims

1. Filter device (1) for cleaning an emission-laden gas (7), comprising a hollow body (21) with a boundary surface (1 1) a clean gas side cavities (24) separates from a raw gas side outer space, wherein at least a portion of the boundary surface (1 1) a gas-permeable filter element (12) for the separation of, for example, particle-like emissions from a gas flowing from the outside through the filter element (12) into the cavity (24) gas (7), and at least one outlet opening (8) in the boundary surface ( 1 1) for removing a filtered gas stream (9) from the cavity (24), characterized in that in the from the filter element (12) to the outlet opening (8) leading flow path at least one gas guide element (2) with at least one schraubfiächenartigen guide surface (5) is arranged, wherein a screw axis (6) of the guide surface (5) in the direction of the outlet opening (8).

2. Filter device according to claim 1, characterized in that the hollow body (21) is cylindrical or conical in shape and at a right angle to the screw axis (6) has a circular or oval cross-section.

3. Filter device according to claim 1 or 2, characterized in that the gas guide element (2) extends at least approximately over the entire length (3) of the cavity (24).

4. Filter device according to one of the preceding claims, characterized in that a cross-sectional area of the outlet opening (8) is substantially smaller than an effective filter surface of the filter element (12).

5. Filter device according to one of the preceding claims, characterized in that the guide surface (5) has the form of a developable screw or Regelschraubfläche (4).

6. Filter device according to one of the preceding claims, characterized in that the guide surface (5) is designed as a two- or multi-start helical surface.

7. Filter device according to one of the preceding claims, characterized in that outer edges (10) of the guide surface (5) abut at least in sections on inner boundary surfaces of the hollow body (21).

8. Filter device according to one of claims 1 to 6, characterized in that an outer diameter (14) of the gas guide element (2) between 40% and less than 100% of an inner diameter of the hollow body (21).

9. Filter device according to one of the preceding claims, characterized in that the gas guide element (2) is designed such that an inner boundary edge of the guide surface (5) at a distance (23) to the screw axis (6), so that the gas guide element ( 2) is recessed in the region around its screw axis (6) and forms a longitudinally extending, at least partially continuous flow channel.

10. Filter device according to one of claims 1 to 7, characterized in that the gas-conducting element (2) divides the cavity into at least two spatially separate, spiral-shaped gas guide channels (13, 13 '), which extend at least over a partial section of the axial length of the hollow body (21) extend.

1 1. Filter device according to one of the preceding claims, characterized in that a length of the gas guide element (2) in the direction of the screw axis (6) at least a quarter, in particular a whole or a multiple of a slope of the guide surface (5).

12. Filter device according to one of the preceding claims, characterized in that the guide surface (5) has a pitch angle (29) from a range with a lower limit of 10 °, in particular 20 °, preferably 35 °, and an upper limit of 80 °, in particular 70 °, preferably 55 ° on most.

13. Filter device according to one of the preceding claims, characterized in that the gas guide element (2) in the interior of the hollow body (21) is secured against rotation.

14. Filter device according to one of the preceding claims, characterized in that the gas guide element (2) relative to the hollow body (21), in particular with respect to the cavity (24), if necessary, separably or removably supported.

15. Filter device according to one of the preceding claims, characterized in that the gas guide element (2) relative to the hollow body (21), in particular with respect to the outlet opening (8) having the front end, mechanically connectable and separable, in particular coupled and, if necessary, can be decoupled.

16. Filter device according to one of the preceding claims, characterized in that the gas-conducting element (2) is produced by means of an extrusion process.

17. Filter device according to one of the preceding claims, characterized in that the filter material (26) is flexible, in particular membrane or bag-like formed and in operation of the filter device (1) on outer edges (10) of the gas guide element (2) rests or supported is.

18. Filter device according to one of the preceding claims, characterized in that extends at least a portion of the gas guide element (2) or an additional gas guide element (2 '), starting from the cavity to beyond the outlet opening (8) addition.

19. Gas guide element (2) for use in a filter device (1) according to one of the preceding claims, characterized in that the gas guide element (2) at least one screw-like guide surface (5) which is designed such that it is a gas flow ( 9) in the cavity (24) of a filter device (1) at least partially a swirling or helical alignment about the screw axis (6) of the guide surface (5) imposes.

20. Gas guide element (2) according to claim 19, characterized in that it has connecting and / or sealing surfaces (28) which are provided for bearing against corresponding connection surfaces or sealing surfaces on a filter element (12) and the gas-conducting element (2 ) by means of at least one coupling device, in particular by means of a plug or screw connection with a filter element (12) can be coupled.

21. Gas guide element according to claim 19, characterized in that the gas-conducting element (2) is designed as a subcomponent of a filter fastening device and is provided for tool-free connection to a filter element (12) and for tool-free separation with respect to a filter element (12).