Belt filter system and process for solids separation using a belt filter system

Abstract

A belt filter system (1) for liquid, especially cooling lubricant, contaminated by solid particles from industrial production, in particular by solid chips, and further in particular metal chips, is shown and described, with a collection tray (2) for cleaned liquid and with a filter device (3) arranged above the collection tray (2), wherein the filter device (3) has a stationary or circulating screen tray (6) for a filter belt (8) transported on or with the screen tray (6) and, preferably, a filter tray (5) open towards the collection tray (2), in particular wherein the belt filter system (1) is designed as an inclined filter system with an ascending and / or circulating screen tray (6).According to the invention, a scraping device (15) with at least one scraper (16) is provided for scraping off solid particles deposited on the filter belt (8) as a result of the sieving effect of the filter belt (8).

Description

[0001] The invention relates to a gravity belt filter system for liquid, especially cooling lubricant, contaminated by solid particles from industrial production, in particular by solid chips, and further in particular metal chips, with a collection tray for cleaned liquid and with a filter device arranged above the collection tray, wherein the filter device has a stationary or circulating screen plate for a filter belt transported on or with the screen plate and, preferably, a filter tray open towards the collection tray, in particular wherein the belt filter system is designed as an inclined filter system with an ascending and / or circulating screen plate, in particular a screen plate arranged in an ascending arrangement in a filter tray of the filter device or a circulating screen plate.

[0002] Furthermore, the present invention relates to a method for separating solids from industrial production, in particular material chips, and more specifically metal chips, from a liquid, in particular a cooling lubricant, using a belt filter system, in particular a belt filter system of the aforementioned type.

[0003] Many machining and forming processes in industrial manufacturing would be impossible without a lubricating and cooling fluid. Depending on the type of machining operation, either lubrication or cooling is more important. Fluids that perform these functions in industrial manufacturing are commonly referred to as cooling lubricants.

[0004] Cooling lubricants can only fulfill their function in industrial manufacturing if they are supplied to the machining points in the cleanest possible condition. Various auxiliary devices are available for cleaning, which separate solid particles from the cooling lubricant fluid.

[0005] A special type of these auxiliary equipment are automatic filtration systems. Gravity belt filter systems are particularly important as compact filtration systems. In a belt filter system, filter paper, nonwoven fabric, or filter woven fabric is used as the filter belt material; modern nonwoven or spun-bound materials can also be used. Due to the sieving effect of the filter belt, solid particles from the contaminated liquid are deposited on the filter belt. The filter cake that builds up over time then takes over the filtration process itself, so that increasingly finer particles are retained over time.

[0006] In a gravity-fed belt filter system, the filter belt runs on a large-mesh floor that serves as the belt's support. Instead of a stationary screen floor over which the filter belt can be pulled in the transport direction from a supply roll or a stack of stored material, an endlessly circulating screen support belt can also be used, which then simultaneously serves as the drive mechanism for the filter belt.

[0007] From DE 20 2010 011 066 U1, a gravity belt filter system is known in which a high geodetic pressure on the filter belt can be achieved, while simultaneously having a simple design. The known gravity belt filter system for liquids, particularly cooling lubricants, contaminated by solid particles from industrial production, especially material chips, comprises a collection tray for the cleaned liquid, a filter unit arranged above the collection tray, and a machine control system. The filter unit has a filter tray with side walls, which is open at the bottom towards the collection tray. Furthermore, a fixed screen plate, or a rotating screen carrier belt, is provided, which is essentially liquid-tight sealed laterally to the walls.

[0008] The separation of solid particles takes place during the filtration process of the belt filter system using a filter belt that can be pulled from a supply roll or a folded stack and guided across the surface of the screen floor, or, if a circulating screen carrier belt is used, driven by the screen carrier belt. The filter belt can be made of filter paper, nonwoven fabric, filter woven fabric, or similar materials. A motor drive for the filter belt is provided, controlled by the machine's control system. A liquid inlet is provided at the filter tank for introducing contaminated liquid into the filter tank.

[0009] The filter basin of the well-known gravity belt filter system is formed by fixed walls, with the screen plate arranged in an ascending configuration within the basin. The gravity belt filter system is thus designed as an inclined filter system. Advantageously, the design can be configured with a screen plate fixed within the filter basin. However, a design with a dynamically positioned screen plate as a circulating support belt is also possible. The height of the filter basin walls is determined to ensure optimal geodetic pressure on the filter belt. The inclined position of the screen plate, and consequently of the filter belt resting upon it, means that as the liquid level rises, it always reaches new, unused sections of the filter belt first. This allows for an optimal filtration rate.Furthermore, the well-known gravity belt filter system has a very compact design.

[0010] During filtration, a filter cake forms on the filter belt. This cake consists of solid particles separated from the liquid being purified by the filter belt's sieving action and deposited on the belt. Once a filter cake of a certain thickness has formed, the filter belt, along with the filter cake, is conveyed to a waste container and subsequently disposed of together. Particularly when separating metallic solids, such as metal shavings generated during metalworking on machine tools, the joint disposal of the filter belt and filter cake results in a significant loss of valuable materials, which is both ecologically and economically disadvantageous.

[0011] Furthermore, the joint disposal of filter belt and filter cake leads to a high volume of waste and therefore to high disposal costs.

[0012] Finally, during transport of the filter belt from the screen floor to the waste container, parts of the filter cake can fall off the belt and then deposit on adjacent components of the filter system. This contributes to increased cleaning efforts.

[0013] The object of the present invention is to provide a belt filter system of the type mentioned above and a method for separating solids from industrial production using a gravity belt filter system, which allows for filtration operation with lower material loss combined with the possibility of simplified recycling of the separated solid particles. Furthermore, it should enable filtration operation with low waste volume and low disposal costs.

[0014] Finally, the filtration process should require minimal cleaning.

[0015] In particular, the object of the present invention is to further develop a gravity belt filter system of the type described in DE 20 2010 011 066 U1.

[0016] The aforementioned problems are solved by a belt filter system with the features of claim 1 and a method for solids separation with the features of claim 14. Preferred embodiments and further developments of the belt filter system and the method according to the invention are the subject of the dependent claims.

[0017] According to the invention, the belt filter system has at least one scraper for removing solid particles deposited on the filter belt as a result of the filter belt's sieving action. The scraper makes it possible to separate a substantial portion of the filter cake or the solid particles deposited on the filter belt, in particular the majority of the deposited solid particles, from the filter belt. According to the invention, the filter belt and the removed portions of the filter cake or the removed solid particles are conveyed via separate transport channels or collected separately. The solid particles separated from the filter belt by the scraper can be fed into a solids collection container. After passing through the separator, the filter belt can be fed to a reel shaft and wound up there.

[0018] In the inventive method for separating solids from industrial production from a liquid using a belt filter system, it is accordingly provided that the solid particles or the filter cake deposited on the filter belt of the belt filter system during filter operation are at least partially, preferably to the greatest extent, scraped off the filter belt and fed separately from the filter belt to a collection container.

[0019] According to the invention, the separated solid material can be easily recycled. Efficient separation of solid particles from the filter belt allows for the recycling of metal particles, particularly metal shavings, and especially high-grade metals such as aluminum or brass. This opens up a new source of revenue through the sale of the solids separated by the scraper, reducing disposal costs and leading to lower operating costs for the belt filter system according to the invention. The possibility of recycling and reusing the separated solid material reduces the ecological footprint of the belt filter system according to the invention. This not only creates competitive advantages but can also lower costs, as resource-efficient operation is possible.Furthermore, the separation of solid particles from the filter belt can help to comply with regulatory requirements in the field of environmental protection and waste disposal, in particular compliance with legal regulations such as the Circular Economy Act (KrWG) for commercial waste.

[0020] Furthermore, waste prevention is promoted by separating the solids from the filter belt, thus reducing the waste volume. In particular, according to the invention, it can be provided that only the spent filter belt, no longer usable for filtration, along with any remaining filter cake residue, is disposed of as waste, while the solids separated by the scraper can be recycled. If necessary, the filter belt can also be reused for filtration after passing through the scraper, provided that the filter cake or the solids deposited on the filter belt have been largely removed.

[0021] Furthermore, by scraping off the solid particles deposited on the filter belt and conveying them separately to a solids collection container, the amount of solid particles that could detach from the filter cake during the further transport of the used filter belt after passing through the separator and then deposit on adjacent components of the filter system is reduced. This makes it possible to operate the belt filter system according to the invention with minimal cleaning effort.

[0022] Preferably, the scraper removes at least 50 wt.%, more preferably at least 70 wt.%, and particularly preferably at least 90 wt.% of the solid particles deposited on the filter belt as a result of the sieving or filtration action of the filter belt. The highest possible separation efficiency supports the economic and ecological advantages of separating the filter cake from the filter belt.

[0023] During filter operation, the scraper, with its scraping surface and / or edge, rests against the filter belt and the filter cake formed on it, and the scraper transmits a contact force to the filter belt. Preferably, the contact force is such that it causes a convex deformation and curvature of the filter belt in the area of ​​the scraper. The filter belt then exhibits a curved or convex contour in the area of ​​the scraper due to the force transmission from the scraper. The depth of the curvature produced by the transmission of the contact force, relative to a straight filter belt contour not subjected to the contact force, can be more than 0.5 cm, preferably more than 1 cm, and further preferably less than 4 cm, particularly preferably less than 3 cm. This ensures a high separation efficiency of the solid particles.At the same time, it is ensured that the force transmission from the scraper does not cause any damage to the filter belt that could impair the further transport of the filter belt after passing the scraper.

[0024] Preferably, the contact force that can be transmitted from the scraper to the filter belt can be at least 10 N, preferably at least 20 N, and, more preferably, at most 80 N, particularly preferably at most 50 N. Particularly preferably, the scraper presses against the filter belt with approximately 25 N (+ / - 5 N).

[0025] Preferably, the scraper rests against the filter belt and the filter cake formed thereon with a scraping edge, wherein the width of the scraping edge can be less than 2 mm, preferably less than 1 mm, and in particular 0.5 mm. The length of the scraping edge can be in the range between 300 mm and 1000 mm, preferably in the range between 400 mm and 600 mm, and particularly preferably in the range of approximately 500 mm.

[0026] The contact pressure transferred from the scraper to the filter belt can range from 0.05 N / mm². 2 and 0.4 N / mm 2 , particularly preferably between 0.1 N / mm 2 and 0.2 N / mm 2 The contact pressure can also be higher.

[0027] It is preferably designed so that the scraper or scraper surface and / or scraper edge extends transversely to the transport direction of the filter belt, in particular across the entire width of the filter belt. This enables effective separation of the deposited solids from the filter belt.

[0028] Preferably, a nonwoven fabric is used as the filter belt material, for example, a nonwoven fabric with the trade name "Filtraloom 31080" from A3 Vliesstoffe GmbH (DE). The nonwoven fabric can have a fiber composition of 100% polyethylene terephthalate (PET). Fiber bonding / orientation can be achieved mechanically or thermally.

[0029] The weight of the fiber fleece can range from 40 g / m² 2 and 200 g / m² 2 preferably between 60 g / m² 2 and 100 g / m² 2 , especially 80 g / m² 2 , amount to.

[0030] The thickness of the fiber fleece can be between 0.6 mm and 1.8 mm, preferably between 0.8 mm and 1.0 mm, and in particular 0.9 mm.

[0031] The maximum tensile force (longitudinal) can be greater than 120 N / 5cm, preferably greater than 130 N / 5cm, preferably greater than 145 N / 5cm, up to greater than 240 N / 5cm.

[0032] The maximum tensile force (transverse) can be greater than 100 N / 5cm, preferably greater than 110 N / 5cm, preferably greater than 115 N / 5cm, up to greater than 370 N / 5cm.

[0033] The elongation (longitudinal) can be between 20% and 30%, preferably between 20% and 24%, particularly preferably 22%.

[0034] The elongation (transverse) can be between 20% and 50%, preferably between 20% and 35%, particularly preferably 22%.

[0035] The air permeability can range from 1,000 l / m² 2 s and 3,400 l / m 2 s, preferably between 2,000 l / m 2 s and 2,900 l / m 2s, especially preferably in the range of 2,500 l / m 2 s lie.

[0036] A structurally simple embodiment of the belt filter system according to the invention provides that the filter belt can preferably be transported upwards in a filter trough of the filter device to a deflection roller of the filter device and is deflected downwards at the deflection roller.

[0037] The scraper can, in particular, be positioned with at least one scraping surface and / or scraping edge to be applied from below against the filter belt and the filter cake formed on the filter belt from deposited solid particles, or be in a scraping position.

[0038] The scraper can be applied against the filter belt, particularly in the circumferential area of ​​the first cross-sectional quadrant of the deflection roller, or be in a scraping position.

[0039] Due to the force transmission from the scraper to the filter belt, the contact area or the wrap angle of the filter belt at the deflection roller can be larger compared to the contact area or wrap angle when the scraper is not in contact with the filter belt and no force transmission from the scraper to the filter belt takes place.

[0040] Preferably, when separating the solid particles from the filter belt, the scraper rests against the filter belt in the area of ​​a free section (Trums) of the filter belt that is not in contact with the deflection roller.

[0041] Below the deflection roller, a guide roller can be provided, over which the filter belt can be fed to a reel shaft of the belt filter system after passing the scraper. The scraper, in a scraping position when force is transmitted from the scraper to the filter belt, is arranged, in a cross-sectional view, with at least one scraping surface and / or scraping edge in the area between the points of contact of a common tangent drawn to the circular cross-section of the deflection roller and the circular cross-section of the guide roller. Preferably, in the scraping position, the scraping surface and / or scraping edge is located in the area between the tangent and a line passing through the centers of the deflection roller and the guide roller.

[0042] The length of the filter belt, i.e., the free, non-contacting section between the deflection roller and the guide roller, can be chosen to be small in order to transfer the greatest possible pressure force from the separator to the filter belt. Preferably, the length of the filter belt is less than 15 cm, particularly preferably less than 10 cm.

[0043] To relieve pressure on the filter belt and to facilitate access to it, the scraper can be adjustable between a wiping position and a release position. In the wiping position, the scraper rests against the filter belt with at least one wiping surface and / or edge, along with the deposited solid particles or filter cake. In the release position, the scraper is pressed against the filter belt, thus relieving pressure on the filter belt. In the release position, there is no contact between the filter belt and the scraper.

[0044] Preferably, the filter assembly comprises a filter trough with side walls, which may be open at the bottom towards the collection tray, allowing filtered liquid to drip downwards into the collection tray. The filter assembly may also include a sieve base that is essentially liquid-tight at its sides. This sieve base can be, as already described, stationary or in the form of a circumferential sieve support band.

[0045] The scraper device can be designed as a sheet metal construction and include a base plate designed to convey solid particles scraped off by the scraper to a collection chute and / or a collection container of the belt filter system according to the invention. In the scraper position, when the scraper rests against the filter belt, the base plate is inclined to the horizontal so that separated solid particles can slide down the collection chute under the influence of gravity and subsequently into a collection container. This ensures, in a simple manner, the complete conveyance of the solid particles and their transfer into the collection container.

[0046] In the scraper position, the base plate can overhang a subsequent collection chute at its edges, allowing for the virtually complete transfer of solid particles onto the collection chute. The solid particles then slide down the chute into a collection container.

[0047] The base plate can be limited by lateral wall sections, giving the scraper a chute-like design. This ensures both the reliable guidance of the solid particles separated from the filter belt on the base plate and their complete transfer to a collection chute.

[0048] Particularly preferably, the scraper is provided and / or formed on the underside of the scraper device, in particular formed and / or held on the underside of the base plate.

[0049] A structurally simple embodiment can provide that the scraper is formed by a bent edge on the upper outer edge of the base plate of the scraper device, relative to the position of the scraper device in the scraper position. A scraper edge and / or scraper surface is then formed by an upper edge and / or edge surface of the base plate, with the scraper being an integral part of the base plate. Alternatively, the scraper can also be formed by a separate component that is connected to the base plate, in particular by welding. For example, a scraper strip, in particular an angled strip, can be provided on the underside of the base plate and connected to the base plate, wherein the scraper strip has at least one scraper edge and / or scraper surface against which the solid particles are scraped from the filter belt in the scraper position.

[0050] To facilitate easy access to the filter belt and / or the interior of the filter assembly, for example for cleaning purposes, the scraper can be adjustable or movable between a scraping position and a release position, wherein the scraper rests against the filter belt in the scraping position and is spaced away from the filter belt in the release position. In particular, the scraper can be movably, and especially pivotably, connected to the filter assembly for this purpose.

[0051] Particularly preferably, the scraper device is movably, and in particular pivotably, connected to the filter device. For example, the wall sections that laterally delimit the base plate of the scraper device can be pivotally connected to the filter device, in particular to the side walls of a filter tray of the filter device.

[0052] The ability to move the scraper assembly together with the scraper relative to the filter assembly, particularly to a filter tray, and especially to pivot it from the scraper position to the release position, allows the scraper to be taken out of contact with the filter belt as needed. This permits access to areas of the filter assembly and / or the filter belt that are covered or closed by the scraper assembly when it is in the scraper position. In particular, the scraper assembly can be pivoted upwards to expose the area below its base for access.

[0053] Furthermore, in particular, the design of the articulated connection between the scraper device and the filter device can be chosen such that the scraper does not come into contact with adjacent components of the filter device when moving from the scraper position to the release position, for example with adjacent deflection and / or guide rollers that are provided for belt guidance.

[0054] Furthermore, a pressure element can be provided to press the filter belt against a deflection and / or guide roller, for example in the form of an angled strip, which can be attached to and / or formed on the underside of the base of the separation device. Preferably, the pressure element is arranged downstream of the scraper in the transport direction of the filter belt.

[0055] The scraper can, preferably solely by its own weight and / or by the spring force of at least one spring element, be automatically forced into a scraping position in which the scraper rests against the filter belt. This ensures that the scraper is securely in contact with the filter belt.

[0056] Preferably, in the case of a hinged connection to the filter assembly, the scraper is pulled downwards solely by its own weight and pressed against the filter belt. Preferably, the contact force that can be transmitted from the scraper to the filter belt can result solely from the weight of the scraper or be a component of the weight of the scraper.

[0057] However, a motorized adjustment of the scraper unit, together with the scraper provided on the scraper unit, into the scraping position is also possible. The contact force that can be transmitted from the scraper to the filter belt can then also be generated by a motor.

[0058] To increase the weight of the scraper and thus ensure a sufficiently high contact force transferred from the scraper to the filter belt, a ballast weight can be provided on the scraper.

[0059] The ballast weight according to the invention is, in particular, a component that does not fulfill a function required for the structural integrity of the scraper device. A ballast weight according to the invention can be formed by a ballast body, for example, a preferably solid cylindrical rod, which is detachably or permanently connected to the scraper device, in particular to a base plate of the scraper device. A detachable connection makes it possible, depending on the material used for the filter belt, to replace an existing ballast weight with one of higher or lower mass and thus influence the magnitude of the contact force transmitted from the scraper device to the filter belt via the scraper.

[0060] To increase the component weight of the scraper device, a base plate and / or wall plate of the scraper device can also have an increased wall thickness in certain areas.

[0061] A practical geometric design provides that the scraper is rotatably mounted around a pivot point and forms an angled lever geometry with a short lever arm facing the filter belt and a long lever arm facing away from it, with the scraper being assigned to the short lever arm and the ballast weight to the long lever arm. This allows a high contact force for scraping off the solid particles to be generated in a structurally simple manner, following the lever principle, solely due to the weight of the scraper.

[0062] Further advantages will become apparent from the following description of the drawings. The drawing illustrates an embodiment of the invention. The invention is not limited to the illustrated embodiment. The drawings show: Fig. 1 A preferred embodiment of a gravity belt filter system according to the invention in a perspective view obliquely from the left; Fig. 2 the belt filter system Fig. 1 now in a perspective view diagonally from above; Fig. 3 a side view of the belt filter system Fig. 1; Fig. 4 a sectional view of the belt filter system Fig. 1 along the intersection line IV-IV from Fig. 1; Fig. 5 the detail V from Fig. 4 and Fig. 6 the detail VI from Fig. 5.

[0063] The in the Fig. Figures 1 to 6, and the preferred embodiment shown, depict a gravity belt filter system 1 for liquids, particularly cooling lubricants, contaminated by solid particles from industrial production, especially material chips, and further specifically metal chips such as aluminum, brass, steel, or cast iron chips. The belt filter system 1 can also be used for separating solid particles from plastics. For the technical background of such a belt filter system, reference is made to the disclosure content of document DE 20 2010 011 066 U1.

[0064] The belt filter system 1 shown here, in accordance with the belt filter system known from document DE 20 2010 011 066 U1, has a collection tray 2 for purified liquid and a filter unit 3 arranged above the collection tray 2, in which the contaminated liquid is filtered. The filter unit 3 is controlled by a machine control system (not shown).

[0065] The filter assembly 3 has a filter tray 5 with side walls 4. The filter tray 5 is open towards the collection tray 2, so that filtered liquid can drip downwards into the collection tray 2. The filter assembly 3 also includes a sieve base 6, which is essentially liquid-tight sealed laterally to the walls 4. Fig. 6), which in the embodiment shown is fixed or can also have the form of a sieve carrier belt.

[0066] The filtering effect is achieved by a filter belt 8, which can be peeled off from a supply roll 7 or a supply folded stack and is guided over the surface of the sieve base 6. The sieve base 6 provides a support for the thin filter belt 8, which preferably consists of fibrous fleece, filter paper, or filter fabric. During the filtration process, a filter cake of solid particles forms on the filter belt 8 in the usual manner. These solid particles are separated from the contaminated liquid by the sieving action of the filter belt 8 and deposited on the filter belt 8.

[0067] The contaminated liquid can be introduced into the filter tray 5 from above. For example, a liquid inlet can be formed on a rear wall 9 of the filter tray 5, or it can be introduced via one of the side walls 4. In particular, the contaminated liquid can be introduced into the filter tray 5 via a cascade box and distributed evenly across the entire width of the filter belt 8.

[0068] The filter belt 8 is fed from below via a deflection roller 10 into a water space 11 formed above the filter belt 8 ( Fig. 5) for the liquid to be purified. Filtration takes place in the lower part of the inclined plane formed by the rising screen plate 6; further up, the resulting filter cake undergoes secondary dewatering. As soon as a certain liquid level is reached above the filter cake, the filter belt 8 is unwound from the supply roller 7 by a motor drive (not shown) and fed upwards along the screen plate 6, over a further deflection roller 12 and a guide roller 13, to a reel shaft 14, and rewound by the reel shaft 14. The filter belt 8, which is simultaneously drawn in at the lower end of the screen plate 6, has a lower flow resistance, so that the liquid level in the water chamber 10 drops. The belt drive can then be stopped.

[0069] Filter belt 8 can be a nonwoven fabric. Depending on the type of nonwoven fabric used, filtration finenesses of approximately 5 to 100 µm can be achieved. Depending on the solids load and viscosity of the contaminated liquid, throughputs of more than 10 m³ / h are possible, depending on the type of nonwoven fabric used. 3 / h up to throughputs of more than 50 m 3 / h

[0070] The illustrated and preferred embodiment now shows a first design feature in that a scraper device 15 with a scraper 16 ( Fig. 6) is provided for scraping off preferably at least a large part of the filter cake formed on the filter belt 8 during filtration. The filter cake consists of solid particles, in particular material chips, and further in particular metal chips, such as aluminum chips, which are separated from a liquid to be purified during filtration as a result of the sieving action of the filter belt 8 and are deposited on the filter belt 8.

[0071] Subsequently, the parts of the filter cake scraped off by the scraper 16 are separated from the filter belt 8 and fed via a collection chute 17 to a collection container 18.

[0072] This creates the possibility of recycling and utilizing the solid particles contained in the filter cake as valuable materials, thus contributing to environmental protection and resource conservation. Furthermore, removing the solid particles from the filter belt 8 reduces the volume of waste. Finally, removing the solid particles also reduces the effort required to clean the filter unit 3, particularly solid particles that might unintentionally detach from the filter belt 8 during its transport to the reel shaft 14 and accumulate in the area below the roller guide of the filter belt 8, requiring removal for the smooth operation of the belt filter system 1.

[0073] As in Fig. As shown in Figure 6, during filter operation a contact force is transferred from the scraper 16 to the filter belt 8, which leads to a curved filter contour 19 or a convex deformation of the filter belt 8 compared to a straight contour 20.

[0074] The curvature depth a of the filter band in the area of ​​the curved filter contour 19 relative to a straight contour 20 can preferably be more than 0.5 cm, in particular approximately 1 cm or more.

[0075] In this context, the scraper 16 can transmit a contact force of at least 10 N, preferably at least 20 N, more preferably at most 80 N, and particularly preferably at most 50 N, to the filter belt 8. This ensures a high separation efficiency when removing the solid particles from the filter belt 8. At the same time, damage to the filter belt 8 caused by the scraper 16 pressing against it can be reliably prevented. In particular, irreversible deformation of the filter belt 8 due to the transmitted contact force, which could negatively affect the further transport of the used filter belt 8 to the reel shaft 14 and the winding of the used filter belt 8, can be prevented.

[0076] The scraper device 15 is primarily a sheet metal construction. A plastic version is not excluded. The following descriptions refer to the sheet metal construction, but can also be implemented with a plastic component.

[0077] The scraper device 15 preferably has a base plate 21 which is bounded by lateral wall sections 22, 23. In the scraper position, the base plate 21 and the lateral wall sections 22, 23 form a transfer chute via which solid particles scraped off by the scraper 16 are transferred to the collection chute 17 and thus into the collection container 18.

[0078] The wiper 16 is formed and / or held on the underside of the wiper device 15.

[0079] Preferably, the scraper 16 and the base plate 21 are formed in one piece. The edge region of the base plate 21 can be angled and / or bent at the upper outer edge of the scraper 16 when it is in the scraping position, thus forming the scraper 16.

[0080] In the wiping position, the wiper 16 rests against the filter belt 8 from below with a wiping edge 24 and / or wiping surface, specifically in the circumferential area of ​​the first quadrant 25 of the circular cross-section of the deflecting roller 12 (see figure). Fig. 6).

[0081] Furthermore, the wrapping angle of the filter belt 8 on the deflection roller 12 is increased as a result of the force transmission from the scraper 16 compared to a position in which the scraper 16 does not act against the filter belt 8.

[0082] The wiper 16 presses, as can be seen from Fig. 6 results in the free, non-supporting section (section) of the filter belt 8 formed between the deflecting roller 12 and the guide roller 13.

[0083] The wiper 16 is in the wiper position as in Fig. The wiper 16 is shown facing upwards and then rests against the filter belt 8 with its scraper edge 24 and / or scraper surface from below or, if necessary, also laterally. In the scraper position, the wiper 16 can also rest fully against the filter belt 8 with the outer edge of the base plate 21, i.e., across the entire width and length of the outer edge.

[0084] The scraper 16 can be removed from the in Fig. The wiper 16 is pivoted from the wiper position shown in Figure 6 to a release position. In the wiper position, the wiper 16 rests against the filter belt 8. In the release position, the wiper 16 is spaced away from the filter belt 8, and no solid particles are separated from the surface of the filter belt 8.

[0085] In particular, the scraper device 15 is pivotably connected to the filter device 3, especially the filter tray 5. In the illustrated embodiment, the scraper device 15 can be pivoted upwards about a pivot joint 26, so that the scraper 16 moves along the Fig. The curved path 27 shown in Figure 6 exits the contact area of ​​the filter belt 8 and is displaced outwards and upwards past the guide roller 13. This allows easy access to the interior of the filter assembly 3 when the scraper device 15 is raised.

[0086] In the preferred embodiment shown, a hinged connection is provided between the lateral boundary walls 22, 23 of the scraper device 15 and the side walls 4 of the filter device 3.

[0087] The contact force with which the scraper 16 rests against the filter belt 8 in the scraping position preferably results solely from the weight of the separation device 15. Alternatively or additionally, at least one spring element can be provided to generate a sufficiently high contact force.

[0088] To increase the contact force, the scraper device 15 can have a ballast weight 28. The ballast weight 28 is then preferably provided at the outer edge 31 of the base plate 21, which is further away from the pivot joint 26.

[0089] The ballast weight 28 can be a cylindrical rod made of an iron or steel material, which is connected to the bottom plate 21 from below, in particular via a welded connection.

[0090] The ballast weight 28 leads to an increase in the mass of the scraper device 15 and thus to an increase in the weight force of the scraper device 15 and the force component resulting from the weight force, which can be transferred from the scraper 16 to the filter belt 8 in the scraper position.

[0091] The ballast weight 28 preferably serves only to increase the mass of the scraper device 15. The ballast weight 28 is not provided for reasons of component strength.

[0092] In particular, the ballast weight 28 causes a shift in the center of gravity of the scraper device 15 relative to the pivot point about the pivot joint 26 radially outwards.

[0093] Following the lever principle, the contact force for scraping off the solid particles is generated. In this context, a suitable geometric design preferably provides that the scraping device 15 forms an angled lever geometry with a short lever arm 29 facing the filter belt 8 and a long lever arm 30 facing away from the filter belt 8, wherein, preferably, the scraper 16 lies on the short lever arm 29 and the ballast weight 28 on the long lever arm 30.

[0094] The chosen lever geometry allows a sufficiently high pressure force to be transferred from the scraper 16 to the filter belt 8.

[0095] The ballast weight 28 leads to a shift of the center of gravity of the scraper 15 outwards, which results in an increase in the pressure force that can be transmitted via the scraper 16 to the filter belt 8 via the angle lever geometry solely due to the mass of the scraper 15.

[0096] The ballast weight 28 is not strictly necessary. If the scraper device 15 is designed as a sheet metal construction, the mass of that device may be sufficient to generate the required pressure force.

[0097] In particular, the base plate 21 and the wall plates 22, 23 can have a wall thickness that is constant in the longitudinal direction and / or in the transverse direction.

[0098] Furthermore, in Fig.Figure 6 shows a pressure element 32, which is designed as an angled strip and extends transversely to the transport direction X of the filter belt 8, preferably over the entire width of the base plate 6. The pressure element 32 is spaced apart from the scraper 16. The pressure element 32 preferably acts from below and / or laterally against the filter belt 8 in the region of the first quadrant 33 of the circular cross-section of the guide roller 13. The pressure element 32 increases the belt tension in the area between the deflection roller 12 and the guide roller 13 and keeps the filter belt 8 taut in this area, thus ensuring a high separation efficiency when scraping off the solid particles. Furthermore, the belt guidance from the guide roller 13 to the reel roller 14 is improved. Reference symbol list: 1 belt filter system 2 drip trays 3 Filter system 4 side wall 5 filter tray 6 sieve tray 7 storage roll 8 filter tape 9 Back panel 10 pulley 11 Water space 12 Pulley 13 Leading role 14 Reel shaft 15 Scraper device 16 wipers 17 Collection slide 18 collection containers 19 Contour gradient 20 Contour gradient 21 Floor plate 22 Wall plate 23 Wall plate 24 Wiper edge Quadrant 25 26 Swivel joint 27 Curved track 28 ballast weight 29 Lever arm 30 Lever arm 31 outer edge 32 Pressure element 33 Quadrant QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2010 011 066 U1 [0007, 0015, 0063, 0064]

Claims

[1] Belt filter system (1) for liquid, in particular cooling lubricant, contaminated by solid particles from industrial production, in particular by solid chips, further in particular metal chips, comprising a collection tray (2) for purified liquid and a filter device (3) arranged above the collection tray (2), wherein the filter device (3) has a stationary or circulating screen tray (6) for a filter belt (8) transported on or with the screen tray (6) and, preferably, a filter tray (5) open towards the collection tray (2), in particular wherein the belt filter system (1) is designed as an inclined filter system with an ascending and / or circulating screen tray (6), characterized by , that a scraping device (15) with at least one scraper (16) is provided for scraping off solid particles deposited on the filter belt (8) as a result of the sieving effect of the filter belt (8). [2] Belt filter system (1) according to claim 1, characterized by , that the wiper (16) rests against the filter belt (8) in a wiping position and transmits a pressure force to the filter belt (8), whereby the filter belt (8) is convexly deformed by the transmission of the pressure force relative to a straight contour (20). [3] Belt filter system according to claim 1 or 2, characterized by that the scraper (16) rests against the filter belt (8) in a scraping position and transmits a contact force to the filter belt, wherein a contact force of at least 10 N, preferably at least 20 N, and, more preferably, of at most 80 N, particularly preferably of at most 50 N, can be transmitted to the filter belt (8) and / or wherein the scraper (16) rests against the filter belt (8) with a scraping edge and / or wherein the surface pressure transmitted by the scraper (16) to the filter belt (8) is between 0.05 N / mm² 2 and 0.4 N / mm 2, preferably between 0.1 N / mm 2 and 0.2 N / mm 2 , amounts. [4] Belt filter system according to one of the preceding claims, characterized by , that the scraper (16) extends transversely to the transport direction of the filter belt (8), in particular over the entire width of the filter belt (8). [5] Belt filter system according to one of the preceding claims, characterized by , that the filter belt (8) is preferably transported upwards to a deflection roller (12) of the filter device (3) and is deflected downwards at the deflection roller (12), wherein the scraper (8) is in a scraping position from below against the filter belt (8) and / or is in contact with the filter belt (8) in the circumferential area of ​​the first cross-sectional quadrant (25) of the deflection roller (12) and / or wherein the wrapping angle of the filter belt (8) at the deflection roller (12) is increased by force transmission from the scraper (16). [6] Belt filter system (1) according to one of the preceding claims, characterized by , that a guide roller (13) is provided below the deflection roller (12), via which the filter belt (8) can be fed to a reel shaft (14) of the belt filter system (1), wherein the scraper (16) rests against the filter belt (8) in the area of ​​the spool when separating the solid particles from the filter belt (8). [7] Belt filter system according to one of the preceding claims, characterized by , that the scraper device (15) has a base plate (21) for transferring solid particles scraped off with the scraper (16) into and / or to a collection chute (17) and / or a collection container (18). [8] Belt filter system according to one of the preceding claims, characterized by that the wiper (16) is provided and / or formed on the underside of the wiper device (15). [9] Belt filter system according to one of the preceding claims, characterized by, that the wiper (16) is adjustable between a wiping position and a release position, wherein the wiper (16) rests against the filter belt (8) in the wiping position and is spaced away from the filter belt (8) in the release position. [10] Belt filter system according to one of the preceding claims, characterized by that the scraper device (15) is movable, in particular pivotable, connected to the filter device (3), in particular a filter tray (5). [11] Belt filter system according to one of the preceding claims, characterized by , that the wiper (16) is moved automatically into the wiping position, preferably solely due to the weight of the wiping device (15) and / or the spring force of at least one spring element, wherein the contact force of the wiper (16) on the filter belt (8) preferably results solely from the weight of the wiping device (15) and / or the spring force of the spring element. [12] Belt filter system according to one of the preceding claims, characterized by that the scraper device (15) has a ballast weight (28). [13] Belt filter system according to one of the preceding claims, characterized by , that the scraper device (15) is rotatably mounted about a pivot point (26) and forms an angle lever geometry with a short lever arm (29) facing the filter belt (8) and a long lever arm (30) facing away from the filter belt (8), wherein the scraper (16) is assigned to the short lever arm (29) and the ballast weight (28) to the long lever arm (30). [14] Method for separating solids from industrial production, in particular material chips, further in particular metal chips, from a contaminated liquid, in particular a cooling lubricant, using a belt filter system, in particular a belt filter system (1) according to one of the preceding claims, wherein, during filter operation, solids deposited on a filter belt (8) are at least partially, preferably to the greatest extent, scraped off the filter belt (8) and transported away separately from the filter belt (8). [15] Method according to claim 14, characterized by , that when the solids are stripped, a contact force is transferred to the filter belt (8) and that the filter belt (8) is convexly deformed due to the force transfer compared to a straight contour (20).

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