Filter system and method for cleaning a filter surface

Abstract

The invention provides a filter system (1) for a water-guided household appliance. The filter system (1) comprises a filter for filtering particles (6) from a fluid and having a filter surface (3), a scraper (2) configured for wiping the filter surface (3), and a scraper drive configured for driving the scraper such that the scraper (2) moves in a translational movement and a rotational movement relative to the filter surface (3). Furthermore, a method for cleaning a filter surface is provided.

Description

Technical Field

[0001] This invention relates to a filtration system and a method for cleaning the filter surface of the filtration system. Background Technology

[0002] Filtration systems, for example, are used in the pump lines or circulation pump lines of water-conducting household appliances and can become clogged very quickly by the particles to be filtered. Mechanical cleaning of the filter surface has proven to be an effective measure (so-called scraping the filter surface). Here, the filtered particles are scraped off the filter surface periodically, continuously, or as needed by means of a mechanical scraper (“scraper”). This periodically operating system is technically simple: in these systems, the scraper moves on a closed track, for example, scraper edges parallel to the axis moving circumferentially inside a cylindrical filter element, or scraper edges radially moving in a circular motion on a flat filter.

[0003] WO 2019081013 A1 describes a washing machine having a drum, a trough below the drum, a water circuit, and a circulation pump and piping for circulating water. The water circuit has a pull-out drawer for introducing detergent or additives. The water circuit is fluidly connected to a detection device for detecting microfibers or impurities in the water. Furthermore, a method for operation is proposed, comprising diverting a volume of water circulating in the circuit and directing it to the detection device for analysis and evaluation of the water in the detection device. Based on the results of this analysis and evaluation, a filtration process is activated using a filter device to filter out the microfibers from the water. The filtered microfibers can be collected and subsequently simply removed from the washing machine.

[0004] DE 11 2006 001 349 T5 describes a device for automatically removing lint in a tunnel washing machine. The device has an opening constructed in a detergent inlet pipe and guide vanes fastened to the inlet pipe along the opening. A cylindrical shroud is rotatably mounted on the inlet pipe and is driven rotatably by a rotary drive roller. The detergent flowing from the opening is guided and filtered through the sidewalls of the cylindrical shroud to separate the lint from the detergent, and is returned to the tunnel washing machine via a collection pipe. As the cylindrical shroud rotates, lint deposited on its circumferential surface inside its sidewalls is shed by the liquid flow guided there by the guide vanes, sinks due to its weight difference, is guided to the lint outlet, and is automatically discharged outwards.

[0005] The idea of ​​using a rotating scraper to move the scraped particles, with the scraper edge inclined relative to the direction of motion (e.g., a helical design of the scraper in a cylindrical or planar spiral in the case of a flat filter), in a direction orthogonal to the direction of motion, to a storage section (e.g., on one side of the cylinder in the case of a cylindrical filter element, or radially outward in the case of a flat filter) and collect them there, works only conditionally. This is because the orthogonal component of the force vector necessary for this propulsive motion is not actually present, and therefore the particle accumulation on the scraper moves only in the direction of motion (e.g., simply around a circle), without additional (within the available range) axial (or radial) movement. This can potentially increase the likelihood of particles moving across the filter surface in certain sections, thereby potentially leading to increased wear on the filter surface. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a filtration system and a method for cleaning a filter surface, said filtration system and said method being able to reliably remove particles from the filter surface while ensuring an extended service life of the filtration system. Furthermore, the object of the present invention is to provide particles to an area provided for this purpose within the filtration system.

[0007] This task is accomplished by a filtration system having the features of claim 1 and a method for cleaning the filter surface having the features of claim 9.

[0008] According to one aspect of the present invention, a filtration system for a water-conducting household appliance is provided, wherein the filtration system comprises:

[0009] - A filter with a filter surface used to remove particles from a fluid.

[0010] - A scraper, the scraper configuration being used to scrape the filter surface, and

[0011] - A scraper driver, the scraper driver configuration being used to drive the scraper in such a way that the scraper moves relative to the filter surface in translational and rotational motion.

[0012] Unlike existing technologies, the scraper of the filtration system of the present invention can perform both translational and rotational movements. Therefore, additionally, an axial (or radial) force can be applied to scrape off particles and collect them in areas of the filtration system specifically provided for this purpose (e.g., in a storage section), and compress them there if necessary. Here, at least the segmented spiral scraper (e.g., a cylindrical spiral in the case of a cylindrical filter, and a planar spiral in the case of a planar filter) can move in two dimensions: on the one hand, it has rotational movement (coaxial with the cylindrical body or orthogonal to the planar filter), and on the other hand, it has a pushing motion (axially in the case of a cylindrical body, and radially in the case of a planar filter). An advantageous operating process of the filtration system can be derived through the periodic combination of these two basic movements.

[0013] Translational motion (also known as pure translation or linear motion) can be a motion in which all points of the scraper (which is constructed, for example, as a rigid body) undergo the same movement (e.g., a parallel displacement in geometry). At a given moment, the velocities and accelerations of all points can be identical. All points can move along parallel trajectories. This contrasts with rotational motion, in which all points of the scraper move circularly about a common axis (the axis of rotation).

[0014] The filtration system can involve a system that receives fluid through an inlet, filters out particles transported with the fluid, and discharges the fluid from the filtration system through an outlet. The fluid can be, for example, a mixture of water, particles, and detergent. Alternatively, the fluid can be a gas carrying particles. The fluid can be supplied to the filtration system through a fluid supply unit so that the filtration system removes the particles and then exits the filtration system from the fluid outlet. The particles can include detergent residues, microplastics, detergent residues, impurities, and the like. The particles can be trapped by the filter, while the fluid can pass through the filter. More precisely, the filter can have a primary region where particles accumulate. An opposing secondary region of the filter can be arranged downstream in the direction of fluid flow. A scraper can remove particles from the primary region (i.e., the filter surface) of the filter by contacting the filter surface. For this purpose, the scraper can move across the filter surface and contact the filter surface with its edges (especially in a surface contact). Therefore, the scraper can be configured to mechanically scrape the filter surface. The scraper edge can have a blade-like configuration. Particles can be lifted from the filter surface by the scraper edge and accumulate in front of the scraper edge in the direction of movement, moving with it. Here, the scraper edge can leave a narrow channel on the filter surface where particles have been removed. Preferably, the scraper configuration is a helical scraper with one or more pitches.

[0015] The filter can have a cylindrical shape, in which case the peripheral surface and / or top surface are configured as the filter surface. Inside the filter, a scraper can be arranged such that it can move relative to the filter to scrape particles off the filter surface. Furthermore, the filter can be constructed from a gauze membrane, a metal sieve, or similar materials. The filter can have a pore size in the range of 10 μm to 100 μm. Therefore, the filter can be adapted to a wide range of applications. Preferably, the filter has a pore size of 25 μm to 50 μm. Within this range, microplastic particles can be reliably filtered from the fluid and even stringent environmental regulations can be met. At the same time, sufficient volumetric flow can be ensured through the filtration system so that household appliances can operate efficiently.

[0016] In the case of a column filter, the ratio between the column diameter and the filter height can be in the range of 0.1 to 0.6. Within this range, particularly good cleaning of the filter surface can be achieved by the scraper, as the resulting filter surface can be reliably cleaned even when the fluid is heavily loaded with particles. Preferably, this ratio is in the range of 0.25 to 0.4. Within this range, it has been found that the scraper actuator can be configured very simply to move the scraper across the filter surface. Therefore, within this range, the optimal balance of the materials used, good volumetric throughput, and good filtration performance is achieved.

[0017] Accordingly, the filtration system according to the invention provides the possibility of scraping the filter, pushing the scraped particles toward the storage section, and compressing these particles in the storage section. Here, the particles are actively moved into the storage section, so that no particles accumulate in the area where filtration is performed. Furthermore, this filtration system is primarily used in locations where, on the one hand, a high surface velocity is necessary during scraping (e.g., for a high degree of filtration performance in the case of large volumes of heavily polluted water; typically, for household appliances such as washing machines or dishwashers with limited installation space for the filter), and on the other hand, the volumetric flow cannot / should not be interrupted during filtration and scraping, for example, in the pump outlet line of a washing machine. Furthermore, it is advantageous to remove the scraped particles from the storage section (or to discharge these particles from the filter housing using an extraction device).

[0018] Preferably, the translational motion includes motion in a first translational motion direction and motion in the opposite second translational motion direction.

[0019] In other words, the scraper can move in two opposing directions during translational motion. In other words, the scraper can oscillate back and forth within the filter. This ensures that particles trapped between the scraper edge and the filter surface do not move indefinitely on the filter surface, but instead remain at the point of change of direction when the direction changes. This improves the durability of the filter surface. Translational motion in one direction can be achieved within one pitch of the spiral scraper. The upward direction. In other words, during the translational motion, the scraper can be displaced relative to the filter surface in one direction by a segment corresponding to the height of the auger scraper. The subsequent rotational motion can similarly be oriented upwards with a pitch and (additionally) a revolution. Thus, the auger scraper can be brought back to its optimal initial position to repeat the translational motion in order to scrape particles off the filter surface.

[0020] Preferably, the scraper and / or scraper driver are configured such that particles are scraped off the filter surface only during translational movement in the first translational direction.

[0021] In other words, while performing the translational movement in the second translational direction, the scraper can simultaneously rotate (i.e., rotate about the axis of rotation) so that although the scraper moves in the second translational direction, it does not scrape particles off the filter surface. In the case of a spiral scraper, this movement is analogous to unscrewing a spiral from the material. Here, the spiral also moves translationally away from the material while simultaneously performing a rotational movement. In the filtration system, this ensures that particles are removed from the filter surface only in the first translational direction and therefore do not move back and forth on the filter surface. In other words, this movement process ensures that particles are discharged by the scraper only in one direction (i.e., in the first translational direction). The advantageous operation of a filtration system with a spiral scraper is described below: Before scraping begins, the filtration system (especially the scraper) can be in an initial position in which the filter (or filter surface) is uniformly occupied by particles. Then, a translational movement in the first translational direction can be performed without rotating the scraper. Here, the scraper can move particles axially along its axis and cause them to accumulate in front of the scraper in the advancing direction. This creates a hollowed-out area behind the scraper. The translational movement in the first direction can be implemented according to the filter's dimensions (e.g., the filter housing's dimensions) until the scraper reaches the end of the filter. Next, the scraper can move in a second direction (opposite to the previously implemented direction) while simultaneously rotating around its axis. During this rotation, the scraper can rotate in such a way that the rotation is proportional to the pitch of the spiral scraper. Therefore, the translational movement in the second direction has no effect on the particle position on the filter surface and repositions the scraper back to its initial position. By periodically repeating the described motion process, particles can accumulate on one side of the filter and may even be compressed by the scraper.

[0022] Furthermore, the filtration system may include a depot, wherein a scraper configuration is used to supply particles to the depot and / or compress the particles within the depot. Here, the depot may be at least partially arranged on the filter surface, so that fluid from the particles collected in the depot can escape through the filter. In particular, the scraper may be configured to compress the particles in the depot (e.g., by further pushing in additional particles). Additionally, a removal device and / or particle gate may be disposed adjacent to the depot, through which particles can be removed from the depot. The aforementioned movement process can be repeated periodically, thereby reliably removing particles from the filter surface even during operation of the filtration system.

[0023] Preferably, the scraper and / or scraper driver are configured such that rotational motion is performed simultaneously during translational motion in the second translational motion direction.

[0024] Here, the rotational motion can be implemented in a rotational manner around the scraper axis. As explained above, this ensures that the particles do not move in the second translational motion direction. Therefore, the scraper can be brought to the initial position without the particles moving a long distance on the filter surface. Consequently, filter wear can be reduced.

[0025] Preferably, the scraper is at least segmentally constructed as a spiral scraper, especially as a spiral scraper, and the scraper rotates about a rotation axis during rotational motion, which is preferably parallel to the filter surface.

[0026] In this implementation, the scraper has a configuration similar to that of a worm pump (e.g., a screw conveyor, especially an Archimedes worm pump), rather than a positive displacement pump with a worm (e.g., an eccentric worm pump or a multi-rotor worm pump). A fundamental element of a worm pump is that, as the worm rotates, it provides an axial force component to the object to be moved forward. In the case of a cylindrical filter, the axis of rotation (that is, in this case, the axis of the scraper) can extend along the central axis of the filter. This allows the scraper to move relative to the filter along the filter surface during rotational motion.

[0027] Preferably, the scraper is configured at least in sections as a planar scraper, especially as a planar spiral, and the scraper rotates about a rotation axis during rotational motion, which is preferably orthogonal to the filter surface.

[0028] In this embodiment, the filter can be a filter with a flat filter surface, preferably, the planar spiral can move as a scraper on the flat filter surface. Preferably, the scraper can have a plate-like shape, which has scraper edges at least segmentally, protruding from the scraper, having a spiral shape, and contacting the filter surface. The scraper rotates relative to the filter surface by rotating the planar spiral about the axis of rotation (i.e., the scraper axis). Here, in this case, the axis of rotation is orthogonal to the filter surface. As in the above embodiment, in this case, the scraper can move in a translational motion to scrape particles off the filter surface in a first translational direction. If the scraper subsequently moves in the opposite second translational direction and simultaneously performs a rotational motion by rotating the scraper about the axis of rotation, the scraper can be guided back to its initial position. In this embodiment, a particularly flat and space-saving filtration system can be provided. In the current embodiment, the basic principle remains the same, that is, the scraper moves in two dimensions.

[0029] Preferably, the ratio between the section of the scraper that rotates during the complete rotation and the section of the scraper that moves relative to the filter surface during the translational motion is less than 1 or greater than 1.

[0030] In other words, the rotational motion and the translational motion can be so different that the scraper moves its edges across the filter surface at different distances in both motions. This ensures that the scraper does not always change its direction and / or type of motion at the same location on the filter surface. This avoids high localized wear. In particular, this can be advantageous when abrasive particles (e.g., lime residue) are present in the fluid to be filtered. Thus, wear-through of the filter surface at one location can be avoided, which would inevitably lead to the complete cessation of the filtration system. Therefore, the preferred ratio of the scraper's displacement in the rotational motion to its displacement in the translational motion is close to 1, for example, close to 0.99 or 1.01. Preferably, this ratio is close to 1, for example, 0.99, meaning that the scraper only makes 99% or 101% of this motion per step, rather than a full pitch (or a full revolution), so that the same motion process is repeated only about every 100 steps at the same location. Therefore, the wear of the filtration system can be distributed as widely as possible across the entire filter surface, thereby increasing the overall service life of the filtration system. This ratio can be obtained, for example, through a gear transmission mechanism (e.g., a gearbox). For example, a scraper driver can be configured to avoid small integer parts of 1 (or steps that increase in small integer parts of 1).

[0031] Preferably, the scraper driver may include a groove and at least one non-circular gear, thereby providing translational and rotational motion of the scraper.

[0032] Therefore, a scraper drive can be provided that enables two-dimensional motion (i.e., rotational and translational motion) of the scraper. Here, the scraper's pushing state (i.e., amplitude, frequency, and variation curve) can be pre-defined by the driving gears, while the rotation can be pre-defined primarily by the gear ratio between these two gears. Thus, the complex two-dimensional motion of the scraper can be easily achieved using a mechanically simple system, contributing to cost savings in the manufacture of the filtration system.

[0033] The scraper may involve at least segmented multi-pitch screws. Scrapers with three pitches are preferred. A spiral scraper may be configured in a threaded manner and include contoured cuts on its cylindrical surface that extend continuously (i.e., along a helix) within the inner or outer wall of the cylinder. This continuous recess can be referred to as the pitch / lead.

[0034] According to another aspect of the present invention, a method for removing filtered particles from a filter surface by means of a scraper is provided, wherein the method includes the following steps:

[0035] - The filter surface is scraped by a scraper in a first translational motion direction relative to the filter surface.

[0036] -Make the scraper move in a second translational direction opposite to the first translational direction, and

[0037] - Rotate the scraper while it moves in the second translational direction.

[0038] Thus, in the case of a cylindrical filter, a basic motion process with two fundamental motion vectors can be generated. On the one hand, the scraper can move in a rotational motion (i.e., without propulsion or translation). In principle, this motion can continue indefinitely because of the periodic symmetry of the filtration system during rotation. Furthermore, the scraper can move in a translational or propulsive motion without rotation. This motion is mechanically limited and therefore must be implemented oscillatingly. This limitation is caused by the size of the filter. The fundamental vectors described above enable a suitable motion process for scraping the filter surface of the filtration system. Therefore, particles on the filter surface can be scraped off first, for example, by a translational motion (propulsive motion), that is, these particles accumulate in front of the scraper edge in the first translational motion direction and move with the scraper edge in the axial direction of the scraper, preferably towards the storage section. In a further motion step, a second translational motion direction opposite to the first translational motion direction (i.e., moving backward and simultaneously rotating forward proportionally to the screw pitch) can be implemented so that the spiral scraper moves back to the initial position without applying force to the particles. By repeating this sequence of steps in principle indefinitely, the entire filter surface can be scraped, and the particles can be destructively moved toward the storage section and / or compressed there.

[0039] Preferably, the scraper rotates during the scraping step. Therefore, a mixed motion can also be achieved during the translational motion in the first translational direction (i.e., during scraping), in which a rotational component is also superimposed during the translational motion. Correspondingly, when the scraper moves in the second translational direction, the rotational component can be reduced. In this case, the filtration system can be controlled particularly easily.

[0040] This invention enables the scraping of the filter surface, the movement of the scraped particles toward the storage section, and / or the compression of the particles in the storage section. Here, particles can be actively pushed into the storage section, thus preventing particle accumulation in the filtration area. A particular advantage of this invention is that, on the one hand, a high surface velocity is necessary during scraping, for example, for high filtration efficiency required in cases of large volume throughput with heavily contaminated fluids and small filter surfaces (typically seen in washing machines or dishwashers with limited installation space for the filtration system). On the other hand, the volumetric flow can be maintained during filtration and scraping, so that the filter status does not need to be considered when pumping or circulating fluid, such as in a washing machine, simplifying the control of the appliance. Furthermore, particles trapped in the storage section can be more easily removed or discharged from the filtration system using a discharge device, facilitating simplified manual operation for the user.

[0041] If translational and rotational motions are depicted in a graph, they do not necessarily produce a jagged curve together. Essentially, it is advantageous that oscillations exist for both types of motion, and these oscillations can be varied within wide limits, for example, so that the motion can be implemented technically simply. Trigonometric functions or curves with rounded corners can be used, for example.

[0042] According to one aspect of the invention, this results in a fundamental motion process having two fundamental motion vectors (this example is illustrated for a cylindrical filter, but it works similarly for other geometries, such as flat cylinders):

[0043] - Rotation without translation (rotational motion). In principle, this motion can continue indefinitely because of the periodic symmetry of the filter during rotation.

[0044] - Propulsion without rotation (translational motion). This motion is mechanically restricted and therefore must be carried out oscillatingly.

[0045] The sequence and combination of these two basic vectors contribute to a suitable and preferred motion process, for example:

[0046] - The propulsive motion first scrapes away particles on the filter surface; that is, these particles accumulate in front of the scraper edge in the direction of scraper movement and move with the axial movement of the scraper edge, preferably towards the storage section.

[0047] - In the second motion step, a spiral motion is implemented opposite to the propulsive motion (moving backward and simultaneously rotating forward proportionally to the pitch of the spiral), so that the spiral scraper returns to its initial position without applying force to the particles.

[0048] - By repeating this sequence of steps in principle indefinitely, the entire filter surface is scraped on the one hand, and the particles move continuously toward the storage section (or are compressed there) on the other hand.

[0049] According to another aspect of the invention, it is advantageous to use the above-described filtration system in water-conducting household appliances. Therefore, sufficient and efficient filtration of fluids can be achieved even in small installation spaces.

[0050] The advantages and features explained above in connection with the device also apply similarly to the method and vice versa. Individual features or aspects of the invention can be combined with each other and have the advantages explained in this context. Attached Figure Description

[0051] The invention will now be explained in detail with reference to the accompanying drawings and advantageous embodiments. Herein lies:

[0052] Figure 1 A schematic diagram showing a scraper according to an embodiment of the present invention is provided.

[0053] Figure 2 A schematic cross-sectional view of a filtration system according to an embodiment of the present invention is shown.

[0054] Figure 3a , 3b 3c and 3c respectively show different operating positions of the scraper in the filtration system according to an embodiment of the present invention.

[0055] Figure 4 A schematic view showing a filtering system according to an embodiment of the present invention is shown.

[0056] Figure 5 The motion process in the filtration system according to an embodiment of the present invention is shown. Representation in a curve graph,

[0057] Figure 6 The motion process in the filtration system according to an embodiment of the present invention is shown. Representation in a curve graph,

[0058] Figure 7 The motion process in the filtration system according to an embodiment of the present invention is shown. The representation in the curve graph, and

[0059] Figure 8 The motion process in the filtration system according to an embodiment of the present invention is shown. Representation in a curve graph. Detailed Implementation

[0060] Figure 1A schematic side view of the scraper 2 and filter surface 3 in a filtration system 1 according to an embodiment of the present invention is shown. Here, in Figure 1 The basic principle of the scraper is particularly illustrated here. The scraper 2 is configured with blade-shaped edges and presses against the filter surface 3 occupied by particles 6, moving across the filter surface 3. Due to the shape of the scraper edges, the particles 6 are removed from the filter surface 3 and accumulate in front of the scraper edges in the direction of movement (first translational movement direction 7), and are further pushed along with the scraper edges. Therefore, the scraper 2 can mechanically scrape the filter surface. Furthermore, in Figure 1 The fluid injection section 8 is schematically shown, indicating from which side of the filter surface 3 the fluid is supplied to the filtration system 1. Particles 6 from the fluid are blocked by the filter surface 3 in the primary region 4. The fluid then flows through the filter surface 3 (i.e., through the filter) and exits the filter in the secondary region 5 of the filter surface 3, further exiting the filtration system 1. Thus, particles 6 are blocked within the filtration system 1.

[0061] The filter (or filter surface 3) is made of gauze membrane or metal sieve and therefore does not apply any directional force to the particles 6. Thus, the particles 6 on the filter surface 3 can overcome the force component opposite to the direction of translational movement during their translational movement. This is mainly due to the interaction of static and sliding friction between the particles 6 and the scraper 2 (or filter surface 3) during the movement of the scraper 2. Consequently, these particles 6 will essentially follow the movement of the forward-propelling edge of the scraper 2. Therefore, when the scraper 2 rotates about the cylindrical axis, the particles 6 move primarily in a circle, while when the scraper moves in the axial direction, the particles move primarily in the axial direction.

[0062] From this understanding, it can be inferred that, for example, in the case of a spiral scraper that rotates and contacts the filter surface, particles move across the filter surface along a circular path. The particles move across the filter surface in a segment, thus lengthening that segment, which may lead to increased wear on the filter surface (or filter).

[0063] Furthermore, the present invention addresses this problem by providing a basic motion process of the scraper 2 with two fundamental vectors. Therefore, in Figure 2 The spiral scraper 2 in a cylindrical filter is schematically shown. Figure 2 A schematic longitudinal section through the filter is shown on the left side, and a top view of the filter is shown on its right side. The circumferential surface of the cylindrical filter forms filter surface 3. Furthermore, in Figure 2 In the example shown, scraper 2 has scraper edges that are inclined relative to the direction of translational movement. In the axial direction of scraper 2 (that is, in...) Figure 2When particle 6 moves to the left or right within the plane of motion, it accumulates in front of the scraper in the direction of movement. In other words, particle 6 moves together with scraper 2 in the direction of movement. For the lateral deflection of particle 6 (in... Figure 2 (In the upward direction), it lacks lateral force components.

[0064] exist Figure 2 The implementation described herein is only one of many possible implementations, because it is also conceivable that the filter surface 3 is configured as a flat filter surface (that is, as in...). Figure 2 The cylindrical filter surface is unfolded (and the scraper 2 is inserted as a spiral). In any case, a basic motion process is generated, which has two basic motion vectors:

[0065] • Rotational motion without translational motion can, in principle, continue indefinitely because of the cylindrical symmetry of the filter in rotational motion.

[0066] It also reveals translational motion without rotational motion, which is mechanically restricted and therefore must be performed oscillatingly.

[0067] The mechanical limitation of translational motion arises from the finite spatial relationships within the filtration system 1, thus preventing the scraper 2 from moving infinitely in one direction. The combination of these fundamental vectors facilitates the motion process according to the invention. The particles 6 on the filter surface 3 are first scraped away by translational motion (i.e., propulsive motion), causing these particles 6 to accumulate in front of the scraper edge in a first translational motion direction 7 and move in the first translational motion direction 7 (i.e., in the axial direction of the spiral scraper) as the scraper 2 moves. Here, the particles 6 can be moved, for example, to a storage section arranged in the filtration system 1. Next, the scraper 2 can move translationally in a second translational motion direction 9 opposite to the first translational motion direction 7 and can simultaneously rotate. In other words, the scraper 2 moves backward and rotates forward simultaneously. Here, the translational motion in the second translational motion direction 9 is proportional to the pitch of the spiral scraper 2. Therefore, the scraper 2 can move back to its initial position (i.e., the initial position) without applying any force to the particles 6. In other words, during the movement of scraper 2 in the second translational direction 9, no particles 6 are removed from the filter surface 3. In principle, this process can be repeated indefinitely to scrape the entire filter surface 3. Furthermore, by repeating this sequence of steps, particles 6 can be continuously moved toward the storage section in the filter and / or compressed there.

[0068] To illustrate this more clearly, the following is based on... Figures 3a to 3c Explain the sequence of steps. In Figures 3a to 3c Shown in Figure 2 The same filtration system 1.

[0069] exist Figure 3a In this configuration, scraper 2 is in its initial position. In this case, filter surface 3 is uniformly occupied by particles 6.

[0070] exist Figure 3b In the process, scraper 2 begins to translate in a first translational direction 7, thereby causing particles 6 to move in the first translational direction 7 (the axial direction of scraper 2) and accumulate in front of scraper 2 in the first translational direction 7. Due to this movement, a vacated area is created behind scraper 2, which can be used for further filtration of the fluid. Figure 3b The arrow in the diagram illustrates the movement of scraper 2 in the first translational direction 7.

[0071] exist Figure 3c The diagram shows how the scraper 2 moves backward in a second translational direction 9 and simultaneously with a rotational motion proportional to the pitch of the scraper 2, so as to bring the scraper back to the... Figure 3a In the initial position shown. Here, the rotational motion of the scraper 2 is proportional to the pitch of the spiral scraper 2, thereby... Figure 3c The motions shown (translational and rotational motions) do not affect particle 6.

[0072] Figure 4 Shown from Figure 2 The filtration system 1 and 3 are in Figures 3a to 3c The diagram shows a schematic view after the periodic repetition of the motion process. Thus, these particles 6 can be supplied to a region (e.g., a storage section) of the filtration system 1 and compressed by subsequently fed particles 6. The particles 6 accumulate in a region of the filtration system 1, where a removal device and / or a particle gate (not shown) can be provided to remove the particles 6 from the filtration system 1.

[0073] Figure 5 This describes the basic movement process of the scraper 2 in the filtration system 1. A graph. Here, the motion in the first and second translational directions 9 is shown on the x-axis. The rotation of scraper 2 about its axis of rotation is shown on the shaft. Figure 3b The translational motion shown corresponds to in Figure 5 A motion arrow like this: This motion arrow extends from the origin of the curve to a point h on the x-axis. Subsequent motion arrows (this motion arrow and...) Points on the axis extending diagonally (2π) correspond to... Figure 3cThe second translational motion 9 shown is combined with the rotational motion. In other words, the scraper 2 combines helical motion (i.e., rotation) about the scraper axis with movement along the scraper axis, resulting in a combined motion. Here, no relative motion occurs between the scraper 2 and the filter surface 3 orthogonal to the scraper edge. Because the system in It exhibits periodic symmetry in the x-direction, so a single step can be performed arbitrarily many times in succession; that is, rotational motion can continue indefinitely. In the x-direction, the motion is mechanically restricted, therefore the motion there must be oscillatory.

[0074] exist Figure 6 Shown in Figure 5 The same curve is used in this embodiment, where the translational motion in the first translational motion direction 7 is smaller than that in the previous embodiment. In other words, the motion of the scraper 2 in the first translational motion direction 7 can correspond to less than the full pitch of the spiral scraper 2. Similarly, in the subsequent combined translational and rotational motion in the second translational motion direction 9, the scraper rotates less than a full revolution. Therefore, for the two basic vectors mentioned above, instead of utilizing the full revolution or full pitch of the scraper 2, a smaller fraction (e.g., 99%) is used. As a result, the same motion is repeated only at the same location after approximately 100 cycles, thereby resulting in a widespread distribution of wear on the filter surface 3 (i.e., across the entire filter surface 3) and thus reducing the risk of point-like filter surface damage.

[0075] exist Figure 7 Another embodiment of the invention is shown below. Therefore, in Figure 7 The graph shown in the previously described figures is illustrated. In the current embodiment, the scraper 2 can perform a mixed motion, such that rotational motion is already performed during translational motion in the first translational motion direction 7. Correspondingly, during translational motion in the second translational motion direction 9, the rotational motion is correspondingly reduced. In other words, as the scraper 2 moves (i.e., when scraping particles 6 from the filter surface 3), a rotational component can also be superimposed, wherein the rotational component is correspondingly reduced when the scraper 2 rotates back.

[0076] exist Figure 8 Another embodiment of the invention is shown here. Figure 8 The curve corresponds to the curve described previously. In the current embodiment, a curved motion trajectory is achieved through a combination of translational and rotational motion, thereby protecting the filter surface 3, especially during the starting and deceleration of the scraper 2. At the same time, it reliably removes particles 6 from the filter surface 3.

[0077] In fact, any periodic function can be conceived for accomplishing the task of this invention, so the combined effect of the translational and rotational motion of the scraper 2 can be adapted to any filtration system.

[0078] List of reference numerals

[0079] 1 Filtration System

[0080] 2 scraper

[0081] 3. Filter surface

[0082] 4. Primary Area

[0083] 5 Secondary regions

[0084] 6 particles

[0085] 7. Direction of the first translational motion

[0086] 8. Fluid Injection Section

[0087] 9. Direction of the second translational motion

Claims

1. A filtration system (1) for a water-conducting household appliance, comprising: - A filter having a filter surface (3) for filtering particles (6) from a fluid. - Scraper (2), the scraper configuration being used to scrape the filter surface (3), and - A scraper driver, configured to drive the scraper so that the scraper (2) moves relative to the filter surface (3) in translational and rotational motion. The scraper (2) is configured in at least a segmental manner as a spiral scraper with one or more pitches.

2. The filtration system (1) according to claim 1. in, The translational motion includes motion in a first translational motion direction (7) and motion in the opposite second translational motion direction (9).

3. The filtration system (1) according to claim 2. in, The scraper (2) and / or the scraper driver are configured such that particles (6) are scraped off the filter surface (3) only during translational movement in the first translational movement direction (7).

4. The filtration system (1) according to claim 2 or 3. in, The scraper (2) and / or the scraper driver configuration is used to simultaneously perform the rotational motion during translational motion in the second translational motion direction (9).

5. The filtration system (1) according to any one of the preceding claims. in, The scraper (2) rotates about a rotation axis during the rotational motion, which is parallel to the filter surface (3).

6. The filtration system (1) according to any one of the preceding claims. in, The ratio between the section of the scraper (2) that rotates during the rotational motion when it is fully rotated and the section of the scraper that moves during the translational motion relative to the filter surface (3) is less than 1 or greater than 1.

7. The filtration system (1) according to any one of the preceding claims. in, The scraper driver includes a groove and at least one non-circular gear, thereby enabling translational and rotational motion of the scraper (2).

8. A method for cleaning filtered particles (6) onto a filter surface (3) using a scraper (2), wherein, The method includes the following steps: - The filter surface (3) is scraped by a scraper (2) in a first translational motion direction (7) relative to the filter surface (3). - Move the scraper (2) in a second translational direction (9) opposite to the first translational direction (7), and - During the movement of the scraper in the second translational direction (9), the scraper (2) is rotated. The scraper (2) is configured in at least a segmental manner as a spiral scraper with one or more pitches.

9. The method according to claim 8, in, The scraper (2) also rotates during the scraping step.

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