Filter device together with a filter element which can be accommodated therein and a method for operating such a filter element together with the device

Abstract

The invention relates to a filter device having a filter housing (10) with an inlet (12) for unfiltered material and an outlet (14) for filtered material and accommodating a replaceable filter element (16) which, when the unfiltered material flows through the filter element from the outside to the inside, not only flows through a hollow-cylindrical element material (18) but also through an element material (22) which closes the hollow cylinder (18) on one free end (20) of the hollow cylinder, on the other free end (24) of the hollow cylinder an element cover (26) with a central interspace (28) is provided for the discharge of filtered material onto the outlet (14) in the filter housing (10), the outlet being connected to the central interspace (28), and the respective element material (18, 22) is accommodated in the filter housing (10) without a seal for full-side inflow from the outside to the inside.

Description

Technical Field

[0001] The present invention relates to a filtration device having a filter housing having an inlet for unfiltered material and an outlet for filtrate, and the filter housing accommodating a replaceable hollow cylindrical filter element for flow of unfiltered material from the outside to the inside. Background Technology

[0002] This design, described in WO2018 / 082799A1, refers to a filter element constructed as a hollow body with the element material extending between two end caps pleated into a single filter fold. The element material is a filter media composed of cellulose. During fluid flow, the cellulose fibers aggregate, thereby forming larger droplets due to the water content of the emulsifier. These droplets descend due to the density difference between water and oil, resulting in the separation of the lower-density medium. The associated filter element performs the aforementioned water removal in a functionally reliable manner and is also low-cost in manufacturing.

[0003] Known filter elements can be fixed in a device with a filter housing by means of a receiving rod that serves as a fixing device. Each end cap of the filter element has a spacing retainer with a sealing function, one on the fixing device and one on a partition of the filter housing. This eliminates the need for additional retaining devices protruding from the outer periphery of the filter element, enabling a space-saving structural design.

[0004] An oil filtration unit is known from EP3334512B1 for removing solid contaminants from contaminated oil, the filtration unit comprising:

[0005] - A housing having a housing inlet and a housing outlet, the housing inlet being adapted to receive contaminated oil from the surrounding environment and to discharge the contaminated oil under a first pressure p1 into an internal opening of the housing, and the housing outlet being adapted to discharge filtered oil into the surrounding environment, and

[0006] - An oil filter for filtering contaminated oil, the oil filter being disposed in an internal opening of a housing and including a filter inlet defined through the outside of the oil filter; an internal filtration volume adapted to receive filtered oil at a second pressure p2, wherein the second pressure p2 is lower than a first pressure p1; and a filter outlet within the housing, the filter outlet providing a fluid / liquid connection between the internal filtration volume and the housing outlet for discharging the filtered oil from the internal filtration volume.

[0007] - The end plate of the oil filter surrounds the filter outlet, and the entire end plate comprises a porous material through which oil can flow, so that at least a portion of the end plate constitutes part of the filter outlet.

[0008] - And the filter outlet includes a hydraulic resistance that forms part of the oil filter, which provides 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 to discharge filtered oil from the internal filter volume to the housing outlet at a third pressure p3, which is lower than the second pressure p2.

[0009] The oil filter or filter element is constructed in the form of a hollow cylinder and is made of cellulose material. The plate-shaped end plates of the oil filter surround the filter outlet of the filter housing; these end plates may be made of a porous material composed of natural or synthetic polymers and cellulose materials. As a known filter element of the oil filter, flow from the inside out is hydraulically resisted by the end plates made of the aforementioned porous material. This hydraulic resistance provides flow restriction between the internal filtration volume and the surrounding environment, thus achieving the aforementioned pressure hierarchy p1>p2>p3. The significance of this pressure hierarchy is that it avoids back pressure on the filter element, which occurs, for example, when a hydraulic pump or similar device is connected to the output side of the filter.

[0010] In addition to the flow from the outside in, what is necessary for the function is that the element material has a sealing device on the bottom side of the filter element relative to the filter housing it houses. This limits the effective filtration area on the filter element and also results in a certain amount of instrumentation cost on the filter housing. Summary of the Invention

[0011] Based on the prior art, the objective of this invention is to further improve upon the known solutions, namely ensuring reliable filtering operation, by making improvements in a technically simple construction and at low cost, thereby improving efficiency during filtering.

[0012] A filtration device according to the invention, together with a filtration element according to the invention and a method according to the invention for operating such a filtration element, solves related tasks.

[0013] In the filtration apparatus according to the invention, it is specified that when the unfiltered material flows through the replaceable filter element from the outside to the inside, not only the hollow cylindrical element material flows through but also the element material that closes the hollow cylinder at one free end. At the other free end of the hollow cylinder, an element cover with a central void is used to discharge the filtrate to an outlet in the filter housing, the outlet being connected to the central void. The corresponding element material is unsealed and contained in the filter housing for full-side circulation from the outside to the inside, resulting in only a simple pressure stage in which the pressure p1 outside the filter element is greater than the discharge pressure p2 on the inside of the hollow cylindrical element material closed to one side. This leads to a significantly improved scavenging balance for the unfiltered flow and proves to be energy-efficient. This is also facilitated by the fact that the hollow cylindrical element material is contained within the filter housing on its filtrate discharge side with continuous discharge openings, thereby allowing flow through the filter element from the bottom to the top. The corresponding upward filtration direction for the filtrate to flow to the outlet side where the pressure is reduced is also advantageous in terms of energy balance.

[0014] Because the filter element material flows from the outside in as a whole and therefore there is no additional sealing device of the filter housing acting on the bottom of the element material, the entire filtration area is available for filtration and the instrument's technical costs are reduced by eliminating such a sealing device.

[0015] The filter element for the filtration device according to the invention is preferably made entirely of cellulose material, within the range of hollow cylindrical element materials and the element material used to enclose the hollow cylinder. This is particularly advantageous because the uniform structure of the element material is beneficial if small particulate contaminants must be separated from the fluid flow, such as when it is desirable to separate so-called oil aging products (varnish) from the fluid flow. The method according to the invention ensures the associated filtration operation using the aforementioned device along with the filter element, and achieves high filtration performance when using the method according to the invention because the pressure level from p1 to p2 is simply present, reducing fluid resistance.

[0016] In a particularly preferred embodiment of the filter element according to the invention, the hollow cylinder of the filter element is composed of a single, preferably identical, annular filter discs, which are fixedly connected, preferably bonded, to each other at their adjacent ends in a stacked arrangement, and the element material that closes the hollow cylinder at one end is composed of closed filter discs. Thus, the filter element can be constructed in a stacked arrangement for flow through identical annular filter discs at any length within the sense of a composite component. Furthermore, the annular filter discs can be manufactured in large quantities as identical components in mass production, which is cost-effective.

[0017] In another preferred embodiment of the filter element according to the invention, it is specified that all filter sheets made of cellulose material have the same filtration characteristics, particularly the same filtration fineness, and the annular filter sheets are all constructed identically in terms of their element material. The cellulose-based filter sheets mentioned are manufactured according to DIN EN ISO 5269-2 using the so-called Rapid-Köthen method, and this standardized method ensures high process safety during manufacturing.

[0018] In another preferred embodiment of the filter element according to the invention, each annular filter disc has a void on its outer peripheral side, the void being formed by cuts or by the spacing between adjacent filter discs. The resulting void improves stability in the blade composite having the individual filter discs and allows for the guidance of unfiltered material flow from the outside to the inside of the filter element having the filter discs. Advantageously, the sheet-shaped element material with a closed hollow cylinder at its ends can be provided with an additional geometry, preferably in the form of an inlet device, which is embedded in the interior of the hollow cylinder. To guide the flow specifically from the bottom to the head of the filter element within the hollow cylindrical filter element, the inlet device preferably has a flared shape with respect to its outer periphery, the maximum cross-section of which transitions integrally into the closed filter disc element material. Because the inlet device on the bottom side of the element material also creates some resistance for the flow through the filter element, it results in improved flow in the head region of the element and thus, overall, a uniform flow distribution during filtration operation.

[0019] In another preferred embodiment of the filter element according to the invention, the hollow cylindrical element material is housed between two end caps, one of which is configured as a double-receiving portion to simultaneously secure the closed, sheet-like element material to the end of the annular element material. This allows the hollow cylindrical element material and the sheet-like element material to be separated by the double-receiving portion and replaced individually with new element material. However, it is preferred that the sheet-like element material be fixedly bonded or welded to the hollow cylindrical element material at its end, so that the sheet transitions seamlessly into the hollow cylinder. In this way, uniform flow is also achieved in the connection area between the sheet-like and hollow cylindrical element materials, and the filter element constructed in this way can be replaced as a whole with a single new element.

[0020] To optimize flow guidance, it is further specified that: each of the two end caps has a central void of the same diameter, and the diameter of the end cap for connection to the outlet of the filter housing corresponds to the inner diameter of the hollow cylinder of the filter element. In particular, the last mentioned feature enables unobstructed discharge of the filtrate towards the outlet of the filtration device.

[0021] Particularly preferred is that the closed-cell element material is made of filter blanks derived from blade builder, particularly from commercially available Rapid-Köthen blade builder equipment.

[0022] In a preferred method for operating a filter element in a filtration device as explained above, the system is used to remove contaminants, preferably oily substances, from a fluid flow. The filter element is housed in a filter housing having an inlet for unfiltered material and an outlet for filtrate. According to the invention, as unfiltered material flows through the filter element from the outside in, it flows not only through the hollow cylindrical element material but also through the element material that closes the hollow cylinder at one free end, guiding the filtrate flow from the inside of the hollow cylinder to the outlet of the filter housing. The corresponding element material is unsealed within the configured filter housing for full-side circulation from the outside in. Oily substances are generally not listed in the literature as "hard" particles and thus do not form true particulate contaminants; rather, they typically refer to sludge-like oil aging products.

[0023] Cellulose used in filter elements can be constructed as a composite material. Here, the cellulose can be combined with fillers, additives, filter aids, etc.

[0024] Silicates such as kaolin, carbonates such as chalk, sulfates such as gypsum and barium sulfate, oxides such as titanium dioxide, and aromatic polyamide fibers and / or carbon fibers are commonly used as fillers. Adhesives, adhesive systems, dryers and wet binders, pigments, dyes, drainage and retention aids, and defoamers are suitable as additives. Diatomaceous earth, silica gel, pearlites, zeolites, or activated carbon can be used as filter aids. Attached Figure Description

[0025] The solution according to the present invention will be explained in detail below with reference to embodiments. In the schematic and non-total-scale drawings:

[0026] Figure 1 The filtration device as a whole is shown in longitudinal section, the filtration device including a filter housing and the filter elements housed therein;

[0027] Figure 2 The filter element used is shown, with arrows indicating the flow characteristics of the filter element.

[0028] Figure 3 A more detailed illustration of the second embodiment of the filter element is shown in longitudinal sectional view;

[0029] Figure 4 Showing something similar to following Figure 3 A side view of the filter element from the outside; and

[0030] Figure 5 A perspective view showing a third embodiment of the filter element. Detailed Implementation

[0031] Figure 1 The filtration apparatus according to the invention is shown as a whole in a strongly simplified form in a longitudinal sectional view. The filtration apparatus has a filter housing 10 having an inlet 12 for unfiltered material and an outlet 14 for filtrate. A replaceable filter element 16 is housed within the filter housing 10, according to the invention... Figure 2 The diagram illustrates that when unfiltered material flows through the filter element from the outside in, it flows not only through the hollow cylindrical element material 18 but also through the element material 22 that seals the hollow cylindrical element 18 at one free end 20. An element cap 26 with a central void 28 is located at the other free end 24 of the filter element 16 or the hollow cylindrical element material 18. This central void is used to drain the filtrate and connect to the outlet 14 of the filter housing 10. A corresponding central void 29 is formed through the free end of the hollow cylindrical element 18. Figure 2 ).

[0032] To replace filter element 16, it is common practice to separate the head-side housing component from the bottom-side or canister-side housing component of filter element 16, and therefore this will not be described in detail here. The upper element cover 26 is pushed onto the nozzle, which is part of the outlet 14, and in this area, a sealing ring 30 acts as the sole sealing device between element 16 and housing 10 on the housing side. Otherwise, the corresponding element materials 18, 22 are left unsealed according to... Figure 1 The diagram is housed in the filter housing 10 for use according to... Figure 2 The diagram shows the flow from the outside inwards across the entire side. Specifically, there is no seal on the bottom area of ​​the filter housing 10 for the enclosed element material 22.

[0033] In the filter element 16 Figure 1 and Figure 2 In the embodiment shown, the enclosed element material 22 is housed in an end cap 32 on the bottom side or the bottom side. This end cap is constructed as a dual-receiving portion, serving to simultaneously secure the enclosed, sheet-like element material 22 and the hollow cylindrical element material 18. It is known to house the corresponding element material of the filter element 16 within the enclosed end cap, and therefore will not be described in detail here. The element materials 18 and 22 of the filter element 16 are preferably constructed entirely of cellulose material; that is, not only the hollow cylindrical element material 18 but also the enclosed element material 22 is constructed entirely of cellulose material. The concept of "enclosed" in the context of the solution of this application means that the enclosed element material 22, while continuously porous, otherwise does not have a fluid outlet, such as a throttling channel for guiding fluid, which could connect the surrounding environment to the hollow cylindrical interior 34 of the hollow cylindrical body 18. In this respect, unfiltered material is introduced into the internal space 34 of the element 16 solely through the porosity of the element material 22 for passage.

[0034] For example, especially according to Figure 3 As shown in the design, the hollow cylinder 18 of the filter element 16 is composed of a single, preferably identical, annular filter sheet 36, which is fixedly connected, preferably bonded to each other, at their adjacent ends in a stacked arrangement or in a stacked sequence. Conversely, according to... Figure 2 The implementation method, along the direction Figure 3Observed from the direction of observation, the bottommost filter 36, as the element material 22 of the free end 18 of the closed hollow cylinder, is not housed in an additional end cap 32, but is directly and fixedly connected to the bottommost filter 36 of the hollow cylindrical element material 18 in the stacking sequence, particularly by fixed bonding or fixed welding. The entire topmost filter 38 constitutes the possibility of accommodating the upper element cap 26, which has a central void 28 whose defining edge has a groove-shaped recess 40 for accommodating according to... Figure 1 The sealing ring 30 is shown in the diagram. The element cover 26 surrounds the outer edge of the uppermost filter 38 on the outer peripheral side and is fixedly connected to the filter, for example by means of an adhesive.

[0035] like Figure 3 As further shown, each filter element 36 can also be composed of partial halves 36a, 36b, which, when viewed radially relative to the longitudinal axis of the filter element 16, have opposing gaps 42 with identical configurations. These gaps are formed by notches or press-ins in the filter element 36, or by the two filter halves 36a, 36b of the filter element 36 intersecting each other. Furthermore, corresponding gaps 44, corresponding to the configuration of the gaps 42, are arranged in a stacked sequence between the filter elements 36. Thus, the corresponding gaps 42, 44 extend from the rectangular central region, tapering at the edge side, into the corresponding filter element 36 or the adjacent half-parts 36, 36b. The aforementioned gaps 42, 44, in the form of notches or press-ins, are only provided on the upper side of the corresponding element materials 18, 22 and are not embedded in the hollow cylindrical internal space 34 of the filter element 16. Figure 3 The possible flow direction of the filter element 16 is indicated by arrows. For the bottom filter 36 in the stacked sequence, the flow is from the bottom side toward the internal space 34 of the filter element 16.

[0036] In accordance with Figure 4 In this modified embodiment, the voids 42, 44 are formed by corresponding circumferential press-ins or cuts. In each case, the voids 42, 44 reinforce the stability of the cellulose element as a whole and contribute to improved flow guidance for the unfiltered material from the outside to the interior 34 of the filter element 16. In each case, four voids 42, 44 are present in each filter sheet 36 or between the sheet halves 36a, 36b of the filter sheet 36, respectively, lying in a common radial plane. In particular, the sheet-shaped element material 22, which is closedly constructed except for its porosity, is made of a filter blank derived from the blade formwork.

[0037] In accordance with Figure 5In one embodiment, each half-section 36a, 36b has radially extending defining rods facing each other as spacing retainers 46, which define gaps 48 between them, similar to gaps 42, 44 in the previously described embodiment, which in turn improve fluid guidance but do not completely penetrate the filter material.

[0038] like Figure 1 As also shown in dashed lines, the interior space 34 may additionally have a flow guiding or inlet device 50 when needed, which has a horn shape for improved flow guidance within the filter element 16, the maximum cross-section of which transitions in one piece into the element material of the enclosed lower filter sheet 36.

[0039] The solution according to the invention is particularly used for removing so-called oily substances from fluid flows, which typically consist of oil aging products that are not listed as "hard particles" in the literature and therefore do not constitute particulate contaminants in the true sense. The application also relates to drainage, particularly since cellulose has water-absorbing properties. This also enables oil-water separation. Finally, particulate filtration is also possible.

Claims

1. A filtration apparatus having a filter housing (10) having an inlet (12) for unfiltered material and an outlet (14) for filtrate, and the filter housing housing accommodating replaceable filter elements (16) wherein, when unfiltered material flows through the filter elements from the outside to the inside, not only hollow cylindrical element material (18) flows through but also element material of a hollow cylinder (18a) formed by the hollow cylindrical element material (18) at one free end (20) of the hollow cylinder, and at the other free end (24) of the hollow cylinder, an end cap (26) having a central void (28) is provided for discharging filtrate to the outlet (14) in the filter housing (10), the outlet being connected to the central void (28), and the corresponding element material is unsealed and accommodated in the filter housing (10) for full-side inflow from the outside to the inside, characterized in that, The hollow cylindrical element material (18) is housed between two end caps (26, 32), one of which is configured as a double-receiving part to simultaneously fix the closed, sheet-like element material to the end of the hollow cylindrical element material (18).

2. A filter element having a hollow cylindrical element material (18), wherein the hollow cylindrical element material has an element material at its free end (20) that closes the hollow cylinder (18a), the corresponding element material being at least partially made of cellulose material, characterized in that, The hollow cylindrical element material (18) is housed between two end caps (26, 32), one of which is configured as a double-receiving part to simultaneously fix the closed, sheet-like element material to the end of the hollow cylindrical element material (18).

3. The filter element according to claim 2, characterized in that, The filter element is configured for use in the filtration device according to claim 1.

4. The filter element according to claim 2, characterized in that, The corresponding component materials are made entirely of cellulose.

5. The filter element according to claim 2, characterized in that, The hollow cylinder (18a) of the filter element (16) is composed of a single annular filter sheet (36), which is fixedly connected to each other at their adjacent ends in a stacked arrangement, and the element material that closes the hollow cylinder (18a) at one end of the hollow cylinder is composed of a closed filter sheet (36).

6. The filter element according to claim 5, characterized in that, The hollow cylinder (18a) of the filter element (16) is composed of a single identical annular filter sheet (36).

7. The filter element according to claim 5, characterized in that, The filter sheets (36) are bonded to each other on their adjacent end sides in a stacked arrangement.

8. The filter element according to claim 5, characterized in that, All filter elements (36) made of cellulose material have the same filtration properties, and the annular filter elements (36) are all constructed identically in terms of their element materials.

9. The filter element according to claim 8, characterized in that, All filter elements (36) made of cellulose material have the same filtration fineness.

10. The filter element according to any one of claims 2 to 9, characterized in that, Each annular filter (36) has a gap (42, 44, 48) on its outer periphery, which is formed by a cut, a press-in portion or by a spacing retention portion (46) between adjacent filter (36a, 36b).

11. The filter element according to any one of claims 5 to 9, characterized in that, The sheet-shaped element material (22) has an additional geometry.

12. The filter element according to claim 11, characterized in that, The additional geometric structure is an inlet device (50), which is embedded in the interior of the hollow column.

13. The filter element according to claim 12, characterized in that, The inlet device (50) has a horn shape in terms of its outer periphery, and the maximum cross-section of the horn shape transitions in one piece into the element material of the closed filter (36).

14. The filter element according to claim 13, characterized in that, The two end caps (26, 32) each have a central void (28, 29) with the same diameter, and the filter element (16) of the end cap (26) can be connected to the outlet (14) of the filter housing (10) with a diameter that substantially corresponds to the inner diameter of the hollow cylinder (18a) of the filter element (16).

15. The filter element according to any one of claims 2 to 9, characterized in that, The closed-cell element material is composed of filter blanks.

16. The filter element according to claim 15, characterized in that, The filter blank comes from the blade builder.

17. A method for operating a filter element according to any one of claims 2 to 16 in a filtration apparatus according to claim 1, the filter element being used to remove contaminants from a fluid flow, and the filter element being housed in a filter housing (10) having an inlet (12) for unfiltered material and an outlet (14) for filtrate, wherein, as unfiltered material flows through the filter element (16) from the outside to the inside, not only through a hollow cylindrical element material (18) but also through a hollow cylindrical element material that is closed at the free end of the hollow cylinder, the filtrate flow being guided from the inside of the hollow cylinder to the outlet (14) of the filter housing (10), and the corresponding element material being unsealed within the filter housing (10) for full-side circulation from the outside to the inside, characterized in that, The hollow cylindrical element material (18) is housed between two end caps (26, 32), one of which is configured as a double-receiving part to simultaneously fix the closed, sheet-like element material to the end of the hollow cylindrical element material (18).

18. The method according to claim 17, characterized in that, The contaminant is oil.

Images