Nozzle comprising first channel and second channel surrounding first channel, and nozzle assembly

Abstract

The invention relates to a nozzle (1.1, 1.2, 1.3), comprising: a first nozzle section (2.1), which is designed as a truncated cone; a first channel forming a first nozzle opening (5.1) in the top surface (3.1) of the first nozzle section (2.1); and second channels, second nozzle openings (5.2) being formed in the lateral surface (3.3) of the first nozzle section (2.1), each second channel having a channel axis (9) inclined with respect to a parallel axis (8) running parallel to the central axis (7) of the nozzle (1.1, 1.2, 1.3). The invention also relates to a nozzle assembly (20) comprising: a supply line (22); a supply line opening; at least one nozzle (1.1, 1.2, 1.3, 1.4) comprising an inlet opening (16); the nozzle (1.1, 1.2, 1.3, 1.4) comprises a recess (26) for abutting the feed line (22), and wherein the nozzle (1.1, 1.2, 1.3, 1.4) is releasably held at the receptacle (25) and is centered, and wherein the nozzle holder (23) is releasably held at the feed line.

Description

Technical Field

[0001] The invention relates to a nozzle for cleaning a filter element by means of a fluid flow, the nozzle comprising a first channel and a second channel surrounding the first channel. The invention also relates to a nozzle assembly comprising a pipe and a nozzle attached to the pipe. Background Art

[0002] Nozzles, in particular air nozzles or liquid nozzles, are known from the prior art in a variety of geometries and for a variety of purposes.

[0003] When cleaning a filter element, such as a cartridge filter, a bag filter, a flat filter or a cylindrical filter, a directed fluid flow is used to remove the filter cake from the filter element. For example, as known from DE 4423439 A1, cleaning is performed by backflow. However, cleaning can also be performed by directing the fluid transversely to the surface of the filter element on which the filter cake settles, so as to shear the filter cake. For example, it is also known from DE 202013100593U1 to clean the filter by means of an air flow.

[0004] In the cleaning method mentioned, in particular for cylindrical filter elements, in which the fluid flow is directed transversely to the inner surface and in the direction of the central axis of the cylindrical filter element, a nozzle is used to generate or direct a specific fluid flow. For example, an air impulse is released from a compressed air tank or compressed air line by means of a solenoid valve and directed onto the filter element via a nozzle. The disadvantage of this method is that the flow is usually not directed uniformly enough over the surface to be cleaned and / or does not have enough momentum to clean the entire surface. In particular, sufficient momentum or a sufficient shearing effect can no longer be achieved beyond a certain distance from the nozzle.

[0005] Furthermore, known nozzles are usually fixedly mounted in a corresponding nozzle assembly and can then only be removed with difficulty from the supply line or from the nozzle assembly, for example, for maintenance or replacement.

[0006] From WO 2017 / 059405 A1, a nozzle for discharging a liquid, such as a suspension, for example for coating applications, is known, the purpose of which is to produce a uniform particle distribution in the spray cone.

[0007] Furthermore, from DE 60318287 T2 a nozzle is known which has a central opening and which is used for discharging a liquid, in particular a fuel, for example by means of a mouthpiece passing through the opening. Summary of the invention

[0008] Based on this situation, the object of the present invention is to provide a nozzle or a nozzle assembly, with the help of which the fluid flow during cleaning of the filter element (in particular by cleaning with a fluid flow transverse to the surface of the filter element) can be improved and which is easy to handle.

[0009] The objects of the invention are achieved by the features of the independent main claim. Advantageous embodiments are provided in the dependent claims. The teachings of the dependent claims can be combined arbitrarily with the teachings of the main claim and the dependent claims, as far as technically feasible.

[0010] Advantages of the claimed aspects of the invention are explained below, and preferred variant embodiments of various aspects of the invention are further described below. The explanations, especially regarding the advantages and definitions of features, are essentially descriptive and preferred rather than limiting examples. If the explanations are limiting, this will be explicitly mentioned.

[0011] Where elements are designated by means of numbers, for example, "first element", "second element" and "third element", the numbering is purely intended to distinguish when designating and does not indicate any interdependency of the elements or a mandatory order of the elements. This means in particular that, for example, a device or process does not have to include a "first element" in order to be able to include a "second element". A device or process may also include a "first element" and a "third element" without necessarily including a "second element". It is also possible to provide several units of a single numbered element, for example, to provide several "first elements".

[0012] According to a first aspect of the present invention, the above-mentioned purpose is achieved by a nozzle for cleaning a filter element by means of a fluid flow, the nozzle comprising: at least one first nozzle section, designed as a hollow truncated cone; at least one first channel, wherein the first channel forms a first nozzle opening in the top surface of the first nozzle section; and a plurality of second channels surrounding the first channel, wherein the second channels form second nozzle openings in the side surface of the first nozzle section, wherein each second channel comprises a channel axis inclined relative to a parallel axis extending parallel to the central axis of the nozzle so as to impose a spiral flow profile on the fluid flow.

[0013] A nozzle is understood to be a device having an inlet side or inlet cross section and an outlet side or outlet cross section, wherein a fluid flows into the nozzle at the inlet side or through the inlet cross section and flows out of the nozzle at the outlet side or through the outlet cross section. In this case, the fluid flow between the inlet side / inlet cross section and the outlet side / outlet cross section, in particular the fluid flow by means of the nozzle opening forming the outlet side or outlet cross section, is affected in terms of its flow characteristics. In particular, the fluid flow is affected in terms of flow profile, flow velocity and mass flow. The flow profile is understood to be the sum of the trajectories of the spatial position and velocity through which the individual fluid particles pass. The fluid is in particular air, another gas or a liquid such as water.

[0014] The filter element is designed, for example, as a cylindrical filter element, a bag filter, a cartridge filter or a flat filter and comprises a filter medium, such as a flannel, which is permeable to a portion of the fluid flow to be filtered and impermeable to another portion of the fluid flow to be filtered. For example, dust and particles are filtered out of the air flow in this way. The retained portion of the fluid flow to be filtered forms a filter cake on and / or in the filter medium at the front side of the filter medium over time or as the amount of fluid that has flowed through the filter medium increases the flow resistance of the fluid. Cleaning involves at least partially removing the filter cake from the surface of the filter medium in order to (again) reduce the flow resistance.

[0015] A hollow truncated cone is understood to be a geometric shape that forms a coaxial connection surface between a circular bottom surface and a circular top surface that is smaller than the bottom surface. Here, due to the hollow design, an inner space that corresponds geometrically to the outer contour is formed at the truncated cone, wherein the inner space is free of material. The truncated cone thus forms a wall that forms the side surface of the outer contour and the side surface of the inner contour. In particular, the inner space forms an inlet opening of the truncated cone at the bottom surface for the entry of a fluid flow.

[0016] A channel is understood to be a recess through a material, in particular a wall or walls, wherein the walls are in particular designed to be parallel to one another and in particular parallel to the channel axis. The cross section of the channel can also be larger or smaller along the channel axis, so that the walls are then, for example, not completely parallel to one another, but, for example, almost parallel. The channel is defined in particular by the direction of the channel axis and the channel geometry. Any channel geometry is possible, in particular with regard to the geometry of the cross section, but the channel is preferably designed as a hole with a circular cross section and a certain aperture.

[0017] The helical shape of the flow profile is determined by the fact that the individual fluid particles follow a helical trajectory. In this respect, a twist is applied to the flow profile or the individual fluid particles.

[0018] Therefore, the technical scheme of the above-mentioned purpose includes the following technical teachings: the first nozzle opening is centrally arranged at the top surface, for discharging the core flow, and a plurality of second nozzle openings are arranged at the side surface around the first nozzle opening, for discharging the external flow. In this case, the first nozzle opening or the first channel arranged to form the first nozzle opening is preferably arranged coaxially with the central axis of the nozzle, that is, the first nozzle opening or the first channel has a channel axis coaxial with the central axis and a wall parallel to the central axis. Therefore, the flow direction of the core flow directly points to the outside of the nozzle. In addition, the second channel is tilted separately so that the external flow has a torsion applied toward the spiral shape or the flow direction applied. The core flow (in the absence of external flow, will fan out with a funnel shape relatively close to the nozzle rear, and therefore will only act on the surface of the filter element with greatly reduced momentum) can be contracted or clustered, and therefore guided by the spiral external flow. Prevent the external flow from fanning out by applying a spiral flow profile, and the external flow acts on the entire flow profile in a contracted / clustered and stable manner in space as a whole with the flow profile. Then, the flow profile stabilized in this way can act in a more targeted manner, in particular at an increased distance from the nozzle at the surface of the filter element, and the increased momentum component is applied to the desired area of ​​the surface. In particular, by means of the precise geometric design of the nozzle, in particular by means of the diameter ratio of the first channel to the second channel, by means of the number and arrangement of the second channels, and by means of the selection of the inclination angle (the second channels are respectively inclined relative to the parallel axis according to the inclination angle), the flow profile can be accurately adapted to a specific filter element, in particular for the development of the diameter of the flow profile or the diameter at the axial distance from the nozzle. Then, the flow profile accurately fills, for example, a cylindrical filter element, and a particularly advantageous shear is achieved at the inner surface of the cylindrical filter element. In short, the inclination of the second channel makes it possible to achieve a particularly stable flow profile and a simple and precise control of the directional characteristics of the nozzle, so that the directional characteristics can be accurately selected for a specific application.

[0019] In one embodiment, the second channel is arranged on an annular path coaxial with the central axis of the nozzle. The flow profile is then advantageously symmetrical about the central axis of the nozzle or about the core flow axis coaxially aligned therewith and therefore particularly stable. In addition, this flow profile is particularly suitable for cleaning cylindrical filter elements. When filtering air streams in industrial applications, this cylindrical shape is the standard geometry of filter elements. In addition, the advantageous feature of the arrangement of the second channel on an annular path coaxial with the central axis at the nozzle is that a uniform pressure distribution is generated in the nozzle so that the material load of the nozzle remains low, and the cross section of the matrix formed by at least the first nozzle section of the nozzle is circular.

[0020] In one embodiment, the first nozzle section comprises a concavely tapering side surface. A concavely tapering side surface or a truncated cone is understood to mean that the side surface is designed not to be linearly strongly tapered, but to be tapered in a concave manner in a manner that decreases from the bottom surface to the top surface in the axial direction of the truncated cone. In this respect, a truncated cone is also understood to be a geometric shape whose side surface has a concavity (and / or convexity) of the side surface compared to a geometrically ideal truncated cone. Advantageously, the concave tapering prolongs the second nozzle channels, so that their cross section increases and the ratio of the outer flow to the total flow profile increases compared to a linearly tapering surface.

[0021] In another embodiment, the nozzle comprises a second nozzle section connected to the bottom surface of the first nozzle section and designed as a hollow cylinder. The nozzle then extends towards its inlet side and comprises an inner region in the second nozzle section, within which the fluid flow can be regulated and stabilized in a laminar manner independently of upstream components before the fluid reaches the nozzle opening. In this way, a stable and uniform or axisymmetric flow can be achieved.

[0022] In a preferred implementation of the above-described embodiment, the second channel extends radially outwards from the inside into the outer wall of the second nozzle segment to form a profile at the inner side of the outer wall. Thus, the second channel overlaps the wall of the second nozzle segment, however, the second channel does not intersect the outer profile of the second nozzle segment. Thus, a groove-shaped recess is formed at the inner side of the wall of the second nozzle segment. Advantageously, within the nozzle, i.e. in the second nozzle segment, a torsion or spiral flow profile is already applied, which is comparable to applying a torsion to a projectile in a rifle by means of rifling arranged in the rifle barrel. In this way, the flow profile is further stabilized.

[0023] Particularly preferably, in the case of the above-described embodiment, the second nozzle section comprises a recess at the bottom surface for adjoining a cylindrical profile extending at an angle to the center axis of the nozzle, the recess being in particular a collar. The second nozzle section can then be placed, for example, in a profile-fitting manner, at an opening in the side wall of the tubular supply line, so that a particularly flow-friendly, uninterrupted, particularly tight transition is formed between the supply line and the nozzle. In this case, the nozzle can be positioned on the supply line vertically or at any other angle with its center axis. By forming the collar, the contact surface of the nozzle at the supply line is increased, for example, in order to provide a sealing device. However, particularly preferably, such a collar can also be used to hold the nozzle at the supply line, in particular for holding it in a form-fitting manner. The collar is preferably designed along the recess for adjoining a cylindrical profile or forming the profile itself.

[0024] In one embodiment, each channel axis of the second channel is inclined at a first inclination angle relative to a first transverse axis perpendicular to the parallel axes and intersecting the central axis of the nozzle. Preferably, the first inclination angle is 0 ° to 45 °, particularly preferably 23 °. For example, the first inclination angle is 1 °, 2 °, 3 °, 5 °, 10 °, 15 °, 20 °, 23 °, 25 °, 30 °, 35 °, 40 °, 45 ° or an angle between these values. The setting of the first inclination angle particularly affects the pitch of the spiral profile of the external flow. The selected first inclination angle preferably achieves a favorable contraction of the flow profile and a favorable range of the flow profile, that is, a sufficient distance from the nozzle at which the flow profile is still stable.

[0025] In another embodiment, each channel axis of the second channel is relative to the second transverse axis that is perpendicular to the parallel axes and perpendicular to the first transverse axis, and is inclined at a second angle of inclination. Preferably, the second angle of inclination is 0 ° to 90 °, and is particularly preferably 45 °. The second angle of inclination is, for example, 1 °, 2 °, 3 °, 5 °, 10 °, 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, 65 °, 70 °, 75 °, 80 °, 85 °, 90 ° or an angle between these values. The diameter of the selected second angle of inclination influences the flow profile or the development of the diameter on the axial distance from the nozzle. The nozzle can advantageously be regulated within the selected range of the second angle of inclination, for cleaning the inner surface in the axial direction of a plurality of cylindrical filter elements, particularly for this cylindrical filter element of a plurality of length-to-diameter ratios.

[0026] Preferably, the ratio of the taper of the nozzle between the inlet cross section and the outlet cross section is between 1:1 and 3:1. The inlet cross section is formed in particular by an inlet opening which is formed by the interior at the bottom surface of the first nozzle section or the second nozzle section. The outlet cross section is the sum of the cross sections of all nozzle openings. At the mentioned ratio, a favorable ratio between the flow velocity and the mass flow of the air flow is achieved for cleaning the filter element by means of air impingement from a pressure tank or a pressure line.

[0027] In one embodiment, the first channel is formed as a circle and has a diameter of 1% to 70% of the nozzle diameter. The nozzle diameter is understood to be the maximum outer diameter of the nozzle. In another embodiment, preferably in combination with this embodiment, each second channel is also formed as a circle and has a diameter of 1% to 70% of the nozzle diameter. With the above diameters, a favorable flow profile for cleaning conventional cylindrical filter elements for air cleaning in industrial applications is achieved. In addition, there is a favorable ratio of core flow to external flow to obtain a stable flow profile with a favorable range.

[0028] Preferably, an odd number of second channels is provided. This avoids point symmetry which may be accompanied by mutually cancelling effects.

[0029] In another embodiment, the nozzle comprises a plurality of third channels, each of which intersects the inner contour of the first channel and extends parallel to the central axis of the nozzle. The third channel serves as the contour of the first channel, whereby the core flow itself has undergone bundling and orientation. Advantageously, a particularly well-oriented and stable flow profile is achieved.

[0030] The nozzle according to the above aspect of the invention is preferably produced by means of an additive manufacturing process. This has the advantage that one or more selected inclination angles can be specifically set for cleaning a specific filter element and can be produced without much effort. In particular, additive manufacturing enables nozzles of complex geometries to be realized at low production costs.

[0031] The object is also achieved by a nozzle assembly for cleaning a filter element by means of a fluid flow, the nozzle assembly comprising: a tubular supply line comprising a supply line opening in a side surface of the supply line, at least one nozzle designed as a hollow body with a bottom surface, wherein the nozzle comprises an inlet opening in the bottom surface, and at least one nozzle holder comprising a receptacle for the nozzle, wherein the nozzle comprises a recess at the bottom surface for abutting the side surface of the supply line so that the inlet opening abuts the supply line and is aligned with the supply line opening, and wherein the nozzle is releasably held and centered at the receptacle of the nozzle holder, and the nozzle holder is releasably held at the supply line. The supply line is connected, for example, to a pressure tank or a pressure line.

[0032] A tubular geometry is understood to be a geometry that extends as a profile primarily in the longitudinal direction. The profile is formed as an arbitrary hollow profile and is formed, for example, as a circle or a polygon. The cross section of the profile can be constant or variable over the longitudinal extent.

[0033] With respect to the nozzle, the terms used in the above description of the nozzle assembly should be understood as the terms understood with respect to the nozzle described above.

[0034] Therefore, the technical solution of the above-mentioned purpose includes the following teaching: the nozzle is held at the supply line by means of a nozzle holder, wherein both the nozzle and the nozzle holder are held at the supply line in a releasable manner. The nozzle holder is designed so that the nozzle is centered relative to the nozzle holder and relative to the supply line. For example, a centering device of corresponding shape is provided on the nozzle and the nozzle holder for this purpose. Therefore, by means of centering, an alignment of the inlet opening of the nozzle with the supply line opening is achieved. By means of the nozzle assembly, it is also advantageously possible to arrange the nozzle at the supply line with less effort and fewer tools. In this way, the nozzle assembly can be easily disassembled and then reassembled to replace the nozzle for maintenance, change the nozzle geometry or for cleaning. The nozzle assembly is also designed to be simple and cheap to manufacture. The above-mentioned nozzle assembly also allows the nozzle to be freely positioned at the pipeline, depending on the positioning of the supply line opening.

[0035] Due to the design of the nozzle assembly as described above, the nozzle is firmly held in all spatial directions at the nozzle holder or the supply line and is particularly held in a torsion-proof manner. This prevents slipping and / or torsion of the nozzle during operation of the nozzle assembly.

[0036] The supply line opening is preferably aligned transversely, in particular exactly perpendicularly, to a central axis of the supply line or oriented at an angle away from the central axis of the supply line.The recess arranged at the bottom surface of the nozzle is oriented at a corresponding angle for abutting a side surface of the supply line.

[0037] In a particularly preferred embodiment of the invention, the nozzle of the nozzle assembly is designed according to the technical solution with a nozzle for the purpose described above. The advantages described in this respect are then correspondingly achieved for the nozzle assembly. In particular, such a nozzle can then be positioned at the supply line so that the flow profile is precisely positioned relative to the filter element for cleaning the surface of the filter element.

[0038] In another preferred embodiment, the nozzle is held at the nozzle holder in a form-fitting manner and, in particular, can be inserted into the recess from the inner side of the nozzle holder covered by the supply line. The form-fitting holding makes it particularly easy to attach the nozzle to the nozzle holder and to center the nozzle. In this case, the form fit is particularly preferably designed so that the nozzle occupies a central position therein. By means of the design in which the nozzle can be inserted into the recess from the inner side of the nozzle holder covered by the supply line, the nozzle can be easily fixed in the housing with the aid of the supply line to achieve centering and fixing. When assembling or disassembling the nozzle assembly, the nozzle is then placed in the recess or removed from the housing when the nozzle holder is released from the supply line.

[0039] In a preferred embodiment of the aforementioned embodiment, the nozzle comprises a collar and is held at the nozzle holder in a form-fitting manner by means of the collar. Such a collar provides a simple means of holding the nozzle centrally and securely at the nozzle holder, in particular if the nozzle can be inserted into the recess from the inside of the nozzle holder hidden by the supply line, and the collar then engages behind the nozzle holder. Furthermore, the collar can be used, for example, as a sealing surface and / or for accommodating a sealing device.

[0040] In a preferred embodiment, the nozzle holder is held at the supply line in a force-fitting manner and, in particular, is clamped at the supply line in a clip-like manner. This enables the nozzle holder to be held securely and to be released quickly. The nozzle inserted in the nozzle holder also allows the nozzle holder to be positioned easily and unhindered on the supply line if the nozzle can be inserted into the nozzle from the inside of the nozzle holder.

[0041] In one implementation of the aforementioned embodiment, the nozzle holder is designed to be hinged or bent open and can be held in a hinged / bent closed position by means of a connecting device and is designed to be clamped on the supply line. The nozzle holder is then also integral in the hinged / bent open position and has no parts that can be lost. In addition, it is particularly easy to position the nozzle holder at the supply line when the nozzle holder is hinged / bent open or partially hinged / bent closed and to hold the nozzle holder at the supply line by closing the connecting device. In the case where the nozzle holder is designed to be hinged / bent open with a sufficient opening angle, the nozzle holder can also be positioned at the supply line in the radial direction, thereby keeping the necessary installation space to a minimum.

[0042] In one embodiment, a plurality of nozzles are arranged at the supply line by means of a corresponding plurality of nozzle holders. The teaching of the technical solution of the described object can then be used for more than one nozzle in the case of a single supply line. In particular, in this case, several filter elements can be cleaned simultaneously, or a single filter element can be cleaned by means of several nozzles. In this case, different nozzles with different geometries or different flow profiles can be used simultaneously.

[0043] Furthermore, the nozzle preferably comprises a projection which is arranged at the inlet opening and projects into the supply line opening. In this way, a simple and safe centering of the nozzle relative to the supply line or the inlet opening relative to the supply line opening is achieved and alignment of the openings with respect to one another is ensured. In the case of a circular design of the inlet opening and the supply line opening, an additional anti-twist protection is provided, for example, by a corresponding form fit between the nozzle and the nozzle holder. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In the following, the invention is explained in more detail based on preferred embodiments with reference to the accompanying drawings. In the accompanying drawings, the term "drawing" is abbreviated to "figure".

[0045] In the attached picture:

[0046] Figure 1a shows a perspective view of a nozzle according to a first exemplary embodiment according to an aspect of the present invention;

[0047] Figure 1b Shown according to Figure 1a A side view of a nozzle;

[0048] Figure 1c Shown according to Figure 1a and Figure 1b A top view of the nozzle;

[0049] Figure 1d Shown according to Figure 1a , Figure 1b and Figure 1c Another stereoscopic view of the nozzle;

[0050] Figure 2a shows a perspective view of a nozzle according to a second exemplary embodiment according to an aspect of the present invention;

[0051] Figure 2b Shown according to Figure 2a A side view of a nozzle;

[0052] Figure 2c Shown according to Figure 2a and Figure 2b A top view of the nozzle;

[0053] Figure 2d Shown according to Figure 2a , Figure 2b and Figure 2c Another stereoscopic view of the nozzle;

[0054] Figure 3 shows a schematic diagram of a nozzle assembly according to an exemplary embodiment according to one aspect of the present invention;

[0055] Figure 4a Shown is the Figure 3 A side view of a nozzle and a nozzle holder of a nozzle assembly;

[0056] Figure 4b Shown according to Figure 3 or Figure 4a A perspective view of a nozzle holder; and

[0057] Figure 4c Shown according to Figure 3 or Figure 4aA stereoscopic view of the nozzle. DETAILED DESCRIPTION

[0058] The described exemplary embodiments are merely examples, which may be modified and / or supplemented in various ways within the scope of the claims. Each feature described for a particular exemplary embodiment may be used independently or in combination with other features in any other exemplary embodiment. Each feature described for an exemplary embodiment of a particular claim category may also be used in an exemplary embodiment of another claim category in a corresponding manner.

[0059] Figure 1a to Figure 1d The nozzle 1.1 of a first exemplary embodiment is shown. The nozzle 1.1 comprises a first nozzle section 2.1 and a second nozzle section 2.2. The first nozzle section 2.1 is designed as a hollow truncated cone having a top surface 3.1 and a bottom surface 3.2, which is not shown. The side surface 3.3 of the truncated cone tapers concavely from the bottom surface 3.2 to the top surface 3.1. The second nozzle section 2.2 is designed as a hollow cylinder and is connected to the bottom surface 3.2 of the first nozzle section 2.1 with a top surface 4.1, which is not shown. In addition, the second nozzle section 2.2 comprises a bottom surface 4.2 and a side surface 4.3, which are not shown.

[0060] The nozzle 1.1 comprises a first channel, which forms a first nozzle opening 5.1 in the top surface 3.1 of the first nozzle section 2.1. In addition, the nozzle 1.1 comprises five second channels, which are arranged on a circular line around the first channel and form second nozzle openings 5.2 in the side surface 3.3. The first channel has a channel axis extending coaxially with the central axis 7 of the nozzle 1.1. In addition, at the first channel, seven third channels overlapping the first channel are formed, which are contoured with grooves 6.1 located at the inner wall of the first channel. The second channel has a channel axis 9, each channel axis 9 being arranged obliquely with respect to a parallel axis 8 parallel to the central axis 7 of the nozzle 1.1. The channel axis 9 of the second channel is arranged obliquely with respect to a first transverse axis 10, which is perpendicular to the parallel axis 8 and intersects the central axis 7 of the nozzle 1.1. In addition, each channel axis 9 of the second channel is inclined at a second inclination angle β about a second transverse axis 11 perpendicular to the parallel axis 8 and perpendicular to the first transverse axis 10. Figure 1d An aligned view of the second channel is shown, from which the course of the channel axis 9 of the second channel can be seen in more detail. Figure 1a It can be seen that the second channel 5.2 protrudes radially into the inner surface of the second nozzle section 2.2 and is contoured there with a groove 6.2.

[0061] Figure 2a to Figure 2dA second exemplary embodiment of a nozzle 1.2 is shown, which corresponds to the nozzle 1.1 in its essential features and differs from the nozzle 1.1 in particular in that it has seven second channels or second nozzle openings 5.2 instead of five second channels or second nozzle openings 5.2. Here, the second channels have a smaller cross section. Furthermore, the nozzle 1.2 is not provided with a third channel. Therefore, the first channel has a smooth inner wall. A repeated description of similar features of the nozzles 1.1 and 1.2 is omitted.

[0062] Figure 3 A nozzle assembly 20 is shown schematically, comprising a pressure tank 21, a supply line 22 connected to the pressure tank 21, and two nozzles 1.3 and 1.4 arranged at the supply line 22. The nozzles 1.3, 1.4 are arranged above the cylindrical filter element 12 and are aligned to clean the inner surface of the filter element 12. The nozzle 1.3 is designed in its basic features to correspond to Figures 1a to 2d The nozzles 1.1, 1.2 are designed in accordance with the present invention and therefore have a clustered flow profile 13, the diameter of which corresponds essentially to the inner diameter of the cylindrical filter element 12 and is therefore particularly advantageously designed for shearing the filter cake at the inner surface of the filter element 12. In the flow profile 13, the spiral shape is indicated by the corresponding direction arrows. Due to the clustering / contraction of the flow profile 13, the flow profile 13 is designed to be stable over approximately the entire length of the filter element 12. In contrast, the nozzle 1.4 is not designed according to the present invention, but is designed according to the prior art and has a flow profile 14, which extends very short behind the nozzle 1.4 and fans out over a large area, with the help of which targeted shearing of the filter cake at the inner surface of the filter element 12 is not sufficient or is only feasible when the pressure in the pressure tank 21 is very high.

[0063] Figures 4a to 4c The nozzle 1.3 is held at the supply line 22 by means of a nozzle holder 23, or the nozzle holder 23 and the nozzle 1.3 are shown separately. The nozzle holder 23 is designed as a clip-shaped part that can be opened in a flexural manner and can be clamped to the round supply line 22 by means of a connecting device 24 designed as a clamping device. The nozzle holder 23 also includes a receiving portion 25 for the nozzle 1.3, which is formed on the one hand by a circular recess 25.1 for inserting the nozzle 1.3 from the inside of the nozzle holder 23 and on the other hand by a hexagonal recess 25.2 for a positive connection with the collar 15 of the nozzle 1.3. The recess 25.2 and the collar 15 can also have any other geometric shapes that correspond to each other for positive fit.

[0064] The nozzle 1.3 comprises a collar 15 having a hexagonal outer contour at the bottom surface 4.2 for form-fitting with the recess 25.2. Here, the collar 15 forms a recess 26 for abutting against the side surface of the supply line 22 in such a way that the collar 15 fits into the inner contour 23.1 of the nozzle holder 23 when the nozzle 1.3 is inserted into the nozzle holder 23 from the inside. In this case, the nozzle 1.3 also comprises a protrusion 27 which protrudes into the inner contour 23.1 of the nozzle holder 23 and surrounds the inlet opening 16 of the nozzle 1.3. Figure 4a As can be seen in FIG. 2 , the projection 27 projects into the nozzle holder 23 and is therefore designed to engage in a supply line opening, not shown, thus ensuring that the inlet opening 16 is aligned with the supply line opening and that the two openings are centered relative to each other.

[0065] Overall, the nozzle 1 .3 is held fixed in place and torque-proof at the nozzle holder 23 . In particular, when the nozzle holder 23 is mounted at the supply line 22 , the nozzle 1 .3 is held in the recess 25 by the supply line 22 .

[0066] Reference numerals list

[0067] 1.1 Nozzle

[0068] 1.2 Nozzle

[0069] 1.3 Nozzle

[0070] 1.4 Nozzle

[0071] 2.1 First nozzle section

[0072] 2.2 Second nozzle section

[0073] 3.1 Top surface of the first nozzle section

[0074] 3.2 Bottom surface of the first nozzle section

[0075] 3.3 Side surface of the first nozzle section

[0076] 4.1 Top surface of the second nozzle section

[0077] 4.2 Bottom surface of the second nozzle section

[0078] 4.3 Side surface of the second nozzle section

[0079] 5.1 First nozzle opening

[0080] 5.2 Second Nozzle Opening

[0081] 6.1 Slots

[0082] 6.2 Slots

[0083] 7 Center axis of nozzle

[0084] 8 Parallel Axis

[0085] 9 Channel axis of the second channel

[0086] 10 First transverse axis

[0087] 11 Second transverse axis

[0088] 12 Filter element

[0089] 13 Flow Contour

[0090] 14 Flow Contour

[0091] 15 Ring

[0092] 16 Entrance opening

[0093] 20 Nozzle assembly

[0094] 21. Pressure tank

[0095] 22 Supply lines

[0096] 23 Nozzle holder

[0097] 24 Connecting device

[0098] 25 Accommodation

[0099] 25.1 Recessed portion of the receiving portion

[0100] 25.2 Recessed portion of the receiving portion

[0101] 26 Recessed portion for abutting the side surface of the supply line

[0102] 27 Protrusion

[0103] α First tilt angle

[0104] β Second tilt angle

Claims

1. A nozzle (1.1, 1.2, 1.3) for cleaning a filter element (12) by means of a fluid flow, comprising: at least one first nozzle section (2.1) configured as a hollow truncated cone; at least one first channel, wherein the first channel forms a first nozzle opening (5.1) in a top surface (3.1) of the first nozzle section (2.1); and a plurality of second channels surrounding the first channel, wherein the second channels form second nozzle openings (5.2) in the side surface (3.3) of the first nozzle section (2.1), Each of the second channels comprises a channel axis (9) inclined relative to a parallel axis (8) extending parallel to a central axis (7) of the nozzle (1.1, 1.2, 1.3) to impose a spiral flow profile (13) on the fluid flow.

2. The nozzle (1.1, 1.2, 1.3) according to claim 1, wherein: The second channel is arranged on an annular path coaxial with the central axis (7) of the nozzle (1.1, 1.2, 1.3).

3. The nozzle (1.1, 1.2, 1.3) according to claim 1 or 2, wherein: The first nozzle section (2.1) comprises a concavely tapering side surface (3.3).

4. The nozzle (1.1, 1.2, 1.3) according to any of the preceding claims, comprising a second nozzle section (2.2) which is connected to a bottom surface (3.2) of the first nozzle section (2.1) and is designed as a hollow cylinder.

5. The nozzle (1.1, 1.2, 1.3) according to claim 4, wherein: The second channel extends radially outwards from the inside into the outer wall of the second nozzle section (2.2) to form a profile at the inside of the outer wall.

6. The nozzle (1.1, 1.2, 1.3) according to claim 4 or 5, wherein: The second nozzle section (2.2) comprises a recess (26) at a bottom surface (4.2) for adjoining a cylindrical profile extending at an angle to the center axis (7) of the nozzle (1.1, 1.2, 1.3), and the recess (26) is in particular a collar (15).

7. The nozzle (1.1, 1.2, 1.3) according to any one of the preceding claims, wherein Each channel axis (9) of the second channel is inclined at a first inclination angle (α) relative to a first transverse axis (10), wherein the first transverse axis (10) is perpendicular to the parallel axis (8) and intersects the central axis (7) of the nozzle (1.1, 1.2, 1.3), wherein in particular, the first inclination angle (α) is 0° to 45°, particularly preferably 23°.

8. The nozzle (1.1, 1.2, 1.3) according to any one of the preceding claims, wherein Each channel axis (9) of the second channel is inclined at a second inclination angle (β) relative to a second transverse axis (11), wherein the second transverse axis (11) is perpendicular to the parallel axis (8) and perpendicular to the first transverse axis (10), wherein in particular, the second inclination angle (β) is 0° to 90°, particularly preferably 45°.

9. The nozzle (1.1, 1.2, 1.3) according to any one of the preceding claims, wherein The nozzle (1.1, 1.2, 1.3) has a taper ratio between the inlet section and the outlet section of between 1:1 and 3:

1.

10. The nozzle (1.1, 1.2, 1.3) according to any one of the preceding claims, wherein The first channel is formed in a circular shape and has a diameter of 1% to 70% of the nozzle diameter, and / or each of the second channels is formed in a circular shape and has a diameter of 1% to 70% of the nozzle diameter.

11. The nozzle (1.1, 1.2, 1.3) according to any one of the preceding claims, comprising a plurality of third channels, each of which intersects the inner contour of the first channel and extends parallel to the central axis (7) of the nozzle (1.1, 1.2, 1.3).

12. A nozzle assembly (20) for cleaning a filter element (12) by means of a fluid flow, comprising: a tubular supply line (22) comprising a supply line opening in a side surface of said supply line (22); at least one nozzle (1.1, 1.2, 1.3, 1.4) designed as a hollow body having a bottom surface (4.2), wherein the nozzle (1.1, 1.2, 1.3, 1.4) comprises an inlet opening (16) in the bottom surface (4.2); and at least one nozzle holder (23) comprising a receptacle (25) for the nozzle (1.1, 1.2, 1.3, 1.4), wherein the nozzle (1.1, 1.2, 1.3, 1.4) comprises a recess (26) at the bottom surface (4.2) for abutting the side surface of the supply line (22) so that the inlet opening (16) abuts the supply line (22) and is aligned with the supply line opening, and Therein, the nozzle (1.1, 1.2, 1.3, 1.4) is releasably held at the receiving portion (25) of the nozzle holder (23) and centered, and the nozzle holder (23) is releasably held at the supply line.

13. The nozzle assembly (20) of claim 12, wherein: The nozzle (1.1, 1.2, 1.3) is designed according to any one of claims 1 to 11.

14. The nozzle assembly (20) according to claim 12 or 13, wherein: The nozzles (1.1, 1.2, 1.3, 1.4) are held at the nozzle holder (23) in a form-fitting manner and can in particular be inserted into the recess (25) from the inner side of the nozzle holder (23) covered by the supply line (22).

15. The nozzle assembly (20) of claim 14, wherein: The nozzle (1.1, 1.2, 1.3, 1.4) comprises a collar (15) and is held on the nozzle holder (23) in a form-fitting manner by means of the collar (15).

16. The nozzle assembly (20) according to any one of claims 12 to 15, wherein: The nozzle holder (23) is held on the supply line (22) in a force-fitting manner and, in particular, is clamped in a clamp-like manner on the supply line (22).

17. The nozzle assembly (20) of claim 16, wherein: The nozzle holder (23) is designed to be hinged or bent open and can be held in a hinged / bent closed position by means of a connecting device (24) and is designed to be clamped on the supply line (22).

18. The nozzle assembly (20) according to any one of claims 12 to 17, wherein: The nozzle (1.1, 1.2, 1.3, 1.4) comprises a projection (27) which is arranged at the inlet opening (16) and projects into the supply line opening.

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