Filtering device

Abstract

The utility model relates to a filtering device which is formed by combining different filtering elements (10 and 12) assembled in a structural unit, one filtering element (10) in the filtering elements is used for cleaning particles from fluid flow, and the other filtering element (12) is used for cleaning oil aging products from the fluid flow, the filter elements (10, 12) are connected in parallel to one another for the cleaning fluid flow. According to the utility model, the possibility that the fluid flow to be treated is separated and the corresponding filter elements are respectively controlled according to a predetermined separation ratio and a specific cleaning possibility is created. In this way, the fluid flow can be treated in a particularly efficient manner.

Description

Technical Field

[0001] The utility model relates to a filtering device. Background Art

[0002] Filter devices are freely available on the market in a variety of embodiments. Such filter devices are used in a filter housing to clean a contaminated fluid, for example in the form of a hydraulic medium, from particle contamination by using the filter material of the filter element and to return the thus cleaned fluid from the filter housing to a fluid circuit, in particular a hydraulic circuit. If, after a large number of filter cycles, the filter material becomes clogged with contaminants, the filter material is used up and the filter element must be removed from the device housing and replaced with a new element for continued operation.

[0003] EP 3 334 512 B1 discloses an oil filter unit for removing solid particles from such contaminated oil, the oil filter unit comprising:

[0004] a housing comprising a housing inlet adapted to receive contaminated oil from the surrounding environment and discharge the contaminated oil to an internal opening of the housing at a first pressure p1, and a housing outlet adapted to discharge filtered oil to the surrounding environment; and

[0005] an oil filter for filtering contaminated oil, the oil filter being arranged in the inner opening of the housing and comprising a filter inlet defined by an outer surface of the oil filter, an inner filter volume and a filter outlet within the housing, the filter volume being adapted to receive the filtered oil at a second pressure p2, the second pressure p2 being lower than the first pressure p1, the filter outlet providing a fluid-liquid connection between the inner filter volume and the housing outlet for discharging the filtered oil from the inner filter volume;

[0006] wherein the end plate of the oil filter comprises a filter outlet, the entire end plate comprising a porous material through which oil can flow, such that at least a portion of the end plate forms a portion of the filter outlet;

[0007] And the filter outlet includes a hydraulic resistance which forms part of the oil filter, the hydraulic resistance providing a fluid / liquid flow restriction between the internal filter volume and the housing outlet to increase a second pressure p2 within the internal filter volume and discharge filtered oil from the internal filter volume into the housing outlet at a third pressure p3, the third pressure p3 being lower than the second pressure p2.

[0008] Furthermore, DE 10 2005 014 360 A1 discloses a filter element with a filter material, which has a plurality of individual filter pleats folded into a star shape, wherein at least one fluid-permeable support element is arranged at least partially in the distance between two adjacent filter pleats and / or is arranged to extend on the inner and / or outer sides of the filter pleats, and the support element is provided with a filter-active substance or itself consists of such a filter-active substance. This results in a filter auxiliary element that serves to reduce the effects of fluid components that reduce the service life, whether in the form of specific oil aging products (which are also called varnish in technical terms) or in the form of other media that damage the fluid. In the filter element arrangements known in this regard, the filter material and the fluid-permeable support element are always flowed through in series one after the other. Utility Model Content

[0009] Starting from this prior art, the object of the invention is to improve the known filter device solutions.

[0010] The stated object is achieved by a filter device having the features described below.

[0011] The filter device according to the utility model is composed of a combination of different filter elements assembled in a structural unit, one of which is used to clean particles or solid contaminants from a fluid flow and another filter element is used to clean oil aging products (paint) from a fluid flow, wherein the filter elements are connected in parallel to each other for the cleaning of the fluid flow. This creates the possibility of separating the fluid flow to be treated and controlling the corresponding filter elements with a predetermined separation ratio and a specific cleaning possibility. This can achieve the treatment of the fluid flow in a particularly effective way. Such a filter device is in principle a component of a hydraulic supply circuit, so that the fluid that has been treated by the structural unit is re-input into the filter device within the scope of the circuit guidance. In addition, in the literature, oil aging products or paint are often not listed as "hard" particles, so that they do not represent particle contaminants in the actual sense; but often involve a sludge-like contaminant of the fluid flow.

[0012] It is preferably provided that the one filter element and the other filter element form a structural unit by being arranged one above the other and separate the unfiltrate side from the filtrate side surrounded by the respective element material by their respective element materials. This makes it possible to achieve a continuous oncoming flow along the entire outer circumference of the structural unit and to achieve a uniform flow of the fluid to be treated over the entire filter element surface.

[0013] In a particularly preferred embodiment of the filter device according to the invention, it is provided that the one filter element for cleaning out particles has a pleated, preferably multi-layered element material, and the other filter element for receiving oil aging products is formed by a plurality of individual annular filter disks arranged one above the other, which are at least partially made of cellulose, preferably completely made of cellulose. Due to the pleating of the element material, the surface area available for the filter element is correspondingly increased, so that a large number of solid particles can be cleaned out of the fluid flow. While in the prior art filter elements made of cellulose are also primarily used to clean off particles (EP 3 334 512 B1) or to separate water from an oil fluid flow (WO 2018 / 082799 A1), in the context of the present invention, annular disks containing cellulose are used to clean off oil aging products (paint), wherein the cellulose fibers - as in the prior art - continue to act as agglomerates when the fluid flows through, thereby forming larger droplets from the water portion of the oil-containing emulsion, which droplets sink downwards due to the difference in density between water and oil, thereby also separating the less dense medium and thus separating the water from the hydraulic medium.

[0014] In another preferred embodiment of the filter device according to the invention, it is provided that the structural unit formed by the one filter element and the other filter element has an end cap at each end, one of the end caps closing the one filter element at the bottom for cleaning out particles, and the other end cap closing the other filter element at the top for cleaning out oil aging products has a through opening for the filtrate flow. In this way, the structural unit as a whole is a replacement product, which can be replaced with a new, unused structural unit within the framework of the entire device when the filter element material is used up.

[0015] In a particularly preferred embodiment of the filter device according to the invention, it is provided that at least one throttling point or orifice point is provided on the filtrate side of the structural unit, which throttling point or orifice point divides the fluid volume flow between the one filter element and the other filter element in a predeterminable ratio. Since the cellulose material usually forms a cleaning medium with a higher density than the pleated filter element material, the flow resistance of the cellulose element is increased in this respect, so that in order to simultaneously and uniformly flow through the structural unit, the throttling point or orifice point is preferably arranged on the filtrate side at the fluid outlet of the one filter element for cleaning out particles and on the filtrate side at the adjacent inlet of the other filter element for cleaning out oil aging products. In this way, the flow resistance at the outlet of the particle filter element can be increased in the direction of the filtrate discharge side of the particle filter, so that a uniform flow of fluid occurs for the two filter elements arranged one above the other.

[0016] In this case, the throttle point or opening point is arranged in a particularly space-saving manner in an intermediate cover between the one filter element and the other filter element.

[0017] In another preferred embodiment of the filter device according to the invention, it is provided that all filter discs containing cellulose material have the same filter properties, in particular the same filter fineness, and that the annular filter discs are constructed identically with regard to their element material. This enables a stacking or stacking construction in which, depending on the filtering task, the filter discs can be stacked one on top of the other as identical components in a predeterminable number in order to obtain a paint element of a predeterminable structural height.

[0018] For improved, less turbulent incident flow, it is provided that the individual annular filter disks have grooves on the outer circumference, which grooves are formed by cutouts, indentations or adjacent spacers between the filter disks.

[0019] Preferably, the closed, disk-shaped element material of the further filter element is formed from a filter blank which preferably comes from a sheet metal former.

[0020] The above-described filter disks made of cellulose are produced according to the so-called fast Kothen method in accordance with DIN EN ISO 5269-2 and, as a standardized method to this extent, allow a high degree of process reliability during production. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The filter device according to the present invention will be described in more detail below according to the embodiment of the invention according to the drawings. Here, the illustration is in principle and not to scale:

[0022] Figure 1 The filter device as a whole is shown in a longitudinal cross-sectional view;

[0023] Figure 2 Shown in accordance with Figure 1 A side view of a modified embodiment of the filter device;

[0024] Figure 3 Shown in accordance with Figure 1 and 2 An oblique perspective view of another modified embodiment of the filter device; and

[0025] Figure 4 The hydraulic circuit diagram is shown in the form of Figures 1 to 3 The principle parallel circuit of the filter device is integrated in a simplified representation of the hydraulic supply circuit, including the motor pump unit and the reserve tank. DETAILED DESCRIPTION

[0026] Figure 1The filter device is shown as a whole, which in this respect forms a structural unit and constitutes a combined assembly of two different filter elements 10, 12, one of which is used primarily to clean particles from a fluid flow and the other filter element 12 is used primarily to clean oil aging products (varnish) from a fluid flow, wherein Figure 1 , the flow guidance is schematically shown in a linear form, wherein arrows indicating the flow direction are arranged on the end side. According to this, the filter device as a whole is flowed from the outside to the inside. It is also clear from the arrow diagram together with the line guidance that the two filter elements 10, 12 are connected in parallel to each other in order to clean the fluid flow in this way. The fluid to be cleaned can consist of a hydraulic medium or hydraulic oil, but also of other fluids accessible for the cleaning discussed here.

[0027] Figure 1 The filter device shown consists of only two filter elements 10 , 12 ; however, within the framework of the device solution according to the invention, different selected arrangements with further filter elements (not shown) are possible.

[0028] Figure 1 The typical operating position of the filter device is shown, and the filter elements 10, 12 are arranged one above the other to form a structural unit and separate with their respective element materials 14, 16 a so-called unfiltrate side 18 from a filtrate side 20 which is surrounded by the respective element material 14, 16 in a hollow cylindrical manner. Figure 1 In the arrangement shown, a further filter element 12 is arranged above one filter element 10; in principle, the arrangement can also be reversed if necessary (not shown). However, the arrangement shown is particularly advantageous with regard to the flow-through behavior of the fluid, which will be described in more detail below.

[0029] The filter element 10 for cleaning out particles has a pleated, preferably multi-layered element material 14. For example, the multi-layered structure of such an element material 14 or filter medium can have the following layer structure from one side toward the other side:

[0030] 1. Metal wire fabric or plastic fabric or plastic grid with a mesh structure,

[0031] 2. Polyester nonwoven fabric,

[0032] 3. Glass fiber mat or melt-blown nonwoven fabric

[0033] 4. Paper nonwovens, glass fiber mats or meltblown nonwovens

[0034] 5. Polyester nonwoven fabric

[0035] 6. Stainless steel-polyester mixed fabric, wire fabric or plastic fabric or plastic grille with mesh structure.

[0036] It should be emphasized here that the described layer structure is only exemplary, but has proven to be particularly effective within the framework of filtration particles. However, different structural possibilities are also possible, and it is advantageous in principle that the pre-filter layer is located upstream of the main filter layer when viewed in the flow direction of the fluid. It can also be advantageous to form the filter pleats with different pleat heights for the support function of the individual filter pleats, wherein preferably pleats with a smaller pleat height are connected between pleats with a relatively larger pleat height. In addition, the star-folded filter layer in the form of the element material 14 can be supported in the usual manner on a hollow cylindrical perforated support tube 22.

[0037] The filter element 12 for receiving oil aging products or paint consists of a plurality of individual annular disks 24, which are arranged one above the other to form a stack or stacking sequence. Such disks are at least partially composed of cellulose, and preferably these disks are completely constructed of cellulose material.

[0038] As especially Figure 1 As shown, in one embodiment, the individual filter discs 24 can also be formed by partial halves 24a, 24b, which have grooves 26 formed identically opposite each other between themselves when viewed diagonally with respect to the longitudinal axis of the structural unit, which grooves are formed by groove-like cutouts or press-ins in the filter disc 24 or by the two filter disc halves 24a, b of the respective filter disc 24 being formed adjacent to each other. In addition, further grooves 28 formed corresponding to the grooves 26 are also present in the stacking sequence between the filter discs 24. The respective grooves 26, 28 therefore taper from the middle area of ​​the rectangle at the edge in a wedge-like manner into the respective filter disc 24 or into the adjacently arranged disc halves 24a, b. The grooves 26, 28 are arranged in the form of cutouts or press-ins only on the upper side of the respective element material 16 and, as in particular Figure 1 As shown, there is no engagement into the hollow cylindrical interior 30 of the filter element 12 , which in this respect also forms the filtrate side 20 of the filter device.

[0039] In accordance with Figure 2 In an embodiment modified in this respect, the grooves 26, 28 are formed by corresponding impressions or cutouts on the circumference, wherein the grooves 26, 28 in each case increase the stability of the cellulose element as a whole and serve to improve the flow guidance of the unfiltered flow from the outside into the interior 30 of the filter element 12. In each case, four grooves 26, 28 are present in a common radial plane per filter disc or between the disc halves 24a, 24b of a filter disc 24. In particular, the element material 16 which forms a closed disc shape despite its porosity is formed from a filter blank from a sheet former. In accordance with Figure 3 In the embodiment of the invention, the individual disk halves 24a, b which mutually form a single filter disk 24 have boundary bars 32 which extend radially toward each other and which delimit recesses 34 between themselves, which in turn serve to improve the channel-like flow guidance; however, they do not completely penetrate the filter element material 16, similar to the recesses 26, 28 according to the above-described embodiment. Figure 1 The arrow line of illustratively shows that the disks 24 arranged one above the other are used to clean the oil aging products from the fluid flow. In this regard, the two filter elements 10, 12 are simultaneously and parallelly flowed from the unfiltrate side 18 toward the filtrate side 20.

[0040] In addition, Figure 1 As shown, the disk 24 arranged at the bottom in the direction of sight toward the figure can also be arranged in the form of a partial half 24a only half. Figures 1 to 3 It is also shown that the structural unit formed by the filter elements 10, 12 has an end cap 36, 38 at the end, one end cap 36 closing the filter element 10 at the bottom for cleaning out particles and the other end cap 38 closing the filter element 12 at the top for cleaning out oil aging products, has a through opening 40 for discharging the filtrate flow from the filter device. Figure 1 , the lower bottom cover 36 can have a flow guide 42 for improved flow guidance, which extends into the filtrate side 20 of the filter element 10. In the present case, the flow guide 42 is formed by a solid block, which has a bounding plane 44 at the end side, which extends transversely to the longitudinal axis of the filter device and which ends at the edge side in a convexly extending peripheral edge 46, which is bounded to the outside by the support tube 22. The height of the flow guide 42 is preferably 1 / 5 to 1 / 4 of the structural height of the filter element 10 for cleaning particles.

[0041] In addition, as Figure 1 , a throttling point or orifice 48 is provided centrally on the filtrate side 20 of the structural unit, which divides the fluid volume flow between the respective adjacent filter elements 10, 12 in a predeterminable ratio depending on the selected free cross-sectional area. The throttling point or orifice 48 is arranged in an intermediate cover 50 between the one filter element 10 and the other filter element 12. In particular, the throttling point or orifice 48 is located at the fluid outlet 52 of the filter element 10 for filtering particles and at the inlet 54 of the filter element 12 adjacent thereto for cleaning off oil aging products and in this respect at the filtrate side 20.

[0042] exist Figure 4In the embodiment of the invention, the basic function of the throttling point or orifice point 48 is shown in more detail with reference to a hydraulic supply circuit with a motor pump unit 56. The motor pump unit 56 draws hydraulic fluid from a reservoir 58 and supplies both filter elements 10, 12 with fluid in the same manner within the framework of the parallel circuit, wherein, as already explained, the throttling point or orifice point 48 is arranged at the outlet 52 of the filter element 10 for particle contamination, as viewed in the direction of fluid flow. Within the framework of the parallel circuit mentioned here, the throttling of the fluid flow at the outlet 52 of the filter element 10 has an effect on the fluid supply at the inlet 54 of the filter element 12. In the embodiment of the invention, the throttling of the fluid flow at the outlet 52 of the filter element 10 has an effect on the fluid supply at the inlet 54 of the filter element 12. Figure 4 In the simplified illustration of the present invention, the filtrate flow at the filtrate outlet side of the two filter elements 10, 12 flows back into the storage tank 58; however, in practice, hydraulic elements such as hydraulic working cylinders, valve devices, hydraulic accumulators, etc. are usually connected to the filtrate side 20 of the filter device, which require the freshly cleaned fluid from the filter device for meaningful operation. Here, the total resistance value R ges The following is obtained:

[0043]

[0044] Here, R1 and R2 are the respective individual resistances of the partial lines with the associated filter elements 10, 12. From this, the total volume flow V is obtained according to the following formula:

[0045]

[0046] Wherein, Δp is the total pressure loss of the filter device.

Claims

1. A filtering device, characterized in that: The filter device is composed of a combination of different filter elements (10, 12) assembled in a structural unit, one of the filter elements (10) being used to clean particles from a fluid flow and the other filter element (12) being used to clean oil aging products from the fluid flow, wherein the one filter element (10) and the other filter element (12) are connected in parallel with each other for cleaning the fluid flow.

2. The filtering device according to claim 1, characterized in that: The one filter element (10) and the other filter element (12) form the structural unit by being arranged one above the other and separate, with their respective element materials, an unfiltrate side (18) from a filtrate side (20) surrounded by the respective element materials.

3. The filtering device according to claim 1 or 2, characterized in that: The one filter element (10) for cleaning off particles has a pleated element material (14), and the other filter element (12) for absorbing oil aging products is formed by a plurality of individual annular filter disks (24) arranged one above the other and consisting at least partially of cellulose.

4. The filtering device according to claim 3, characterized in that: The element material (14) of the filter element (10) is multi-layered.

5. The filtering device according to claim 3, characterized in that: These filter discs (24) consist entirely of cellulose.

6. The filtering device according to claim 1 or 2, characterized in that: The structural unit formed by the one filter element (10) and the other filter element (12) has an end cap at each end side, wherein one end cap (36) closes the one filter element (10) at the bottom side for cleaning out particles, and the other end cap (38) closes the other filter element (12) at the top side for cleaning out oil aging products and has a through opening (40) for the filtrate flow.

7. The filtering device according to claim 2, characterized in that: At least one throttling point or orifice point (48) is provided on the filtrate side (20) of the structural unit, which divides the fluid volume flow between the one filter element (10) and the other filter element (12) in a predeterminable ratio.

8. The filtering device according to claim 7, characterized in that: The throttling point or orifice point (48) is arranged on the filtrate side (20) at a fluid outlet (52) of the one filter element (10) for cleaning out particles and at an adjacent inlet (54) of the other filter element (12) for cleaning out oil aging products.

9. The filtering device according to claim 7 or 8, characterized in that: The throttle point or orifice point (48) is arranged in an intermediate cover (50) between the one filter element (10) and the other filter element (12).

10. The filtering device according to claim 3, characterized in that: All filter disks (24) containing cellulose material have the same filter performance, and the annular filter disks (24) are all designed identically with regard to their element materials.

11. The filtering device according to claim 10, characterized in that: All filter discs (24) comprising cellulose material have the same filter fineness.

12. The filtering device according to claim 3, characterized in that: The individual annular filter disks (24) have grooves on the outer circumference, which are formed by cutouts, press fits or by adjacent spacers (32) between the filter disks (24).

13. The filtering device according to claim 1 or 2, characterized in that: The closed disk-shaped element material (16) of the further filter element (12) is formed from a filter blank.

14. The filtering device according to claim 13, characterized in that: The filter blank comes from a sheet former.

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