Filter System and Filter Element with Fiberglass-Containing Filter Medium and Wound Body Fiberglass-Barrier

Abstract

A filter system with a filter housing that has an inlet for the fluid to be filtered and an outlet for the filtered fluid. A filter element is arranged in the filter housing and is provided with a fiberglass-containing filter medium. A fiberglass barrier for retaining fiberglass particles contained in the filtered fluid is arranged fluidically downstream of the fiberglass-containing filter medium. The fiberglass barrier is a wound body of a wound filter material with an average pore size of smaller than 20 m. The wound body has a maximum winding thickness of 1.5 mm.

Claims

1. A filter system for filtering a fluid, the filter system comprising: a filter housing comprising an inlet for the fluid to be filtered and an outlet for the filtered fluid; a filter element arranged in the filter housing and comprising a fiberglass-containing filter medium; a fiberglass barrier configured to retain fiberglass particles contained in the filtered fluid, wherein the fiberglass barrier is arranged fluidically downstream of the fiberglass-containing filter medium; wherein the fiberglass barrier is a wound body comprising a wound filter material with an average pore size of smaller than 20 m; wherein the wound body comprises a maximum winding thickness of 1.5 mm.

2. The filter system according to claim 1, wherein the filter material of the wound body comprises a maximum thickness that amounts to between 0.1 mm and 1.5 mm.

3. The filter system according to claim 1, wherein the wound body comprises one to four windings of the filter material.

4. The filter system according to claim 3, wherein the wound body comprises precisely two of the windings of the filter material.

5. The filter system according to claim 1, wherein the filter material of the wound body is selected from the group consisting of a nonwoven, a knit material, a knotted material, and a woven material.

6. The filter system according to claim 5, wherein the nonwoven is comprised of meltblown fibers.

7. The filter system according to claim 1, further comprising a support body, wherein the wound body is arranged and held on the support body.

8. The filter system according to claim 7, wherein the support body is a sleeve.

9. The filter system according to claim 7, wherein the support body is an integral component of the filter housing or an integral component of the filter element.

10. The filter system according to claim 1, wherein the filter material of the wound body comprises an air permeability of 10 l/(cm.sup.2*s) to 80 l/(cm.sup.2*s).

11. The filter system according to claim 10, wherein the air permeability is <50 l/(cm.sup.2*s)

12. The filter system according to claim 11, wherein the air permeability is <30 l/(cm.sup.2*s).

13. A filter element for filtering a fluid, the filter element comprising: a fiberglass-containing filter medium; a fiberglass barrier arranged fluidically downstream of the fiberglass-containing filter medium and configured to retain fiberglass particles contained in the filtered fluid; wherein the fiberglass barrier is a wound body comprising a wound filter material with an average pore size of smaller than 20 m; wherein the wound body comprises a maximum winding thickness of 1.5 mm.

14. The filter element according to claim 13, wherein the filter material of the wound body comprises a maximum thickness between 0.1 and 1.5 mm.

15. The filter element according to claim 13, wherein the filter material of the wound body is selected from the group consisting of a nonwoven, a knit material, a knotted material, and a woven material.

16. The filter system according to claim 15, wherein the nonwoven is comprised of meltblown fibers.

17. The filter element according to claim 13, wherein the filter material of the wound body comprises a grammage that amounts to 20 g/m.sup.2 to 200 g/m.sup.2.

18. The filter element according to claim 13, wherein the filter material of the wound body comprises an air permeability of 10 l/(cm.sup.2*s) to 80 l/(cm.sup.2*s).

19. The filter element according to claim 18, wherein the air permeability is <50 l/(cm.sup.2*s)

20. The filter element according to claim 19, wherein the air permeability is <30 l/(cm.sup.2*s).

21. The filter element according to claim 13, further comprising a support body, wherein the wound body is arranged and held on the support body.

22. The filter element according to claim 21, wherein the support body is a grid-shaped central tube of the filter element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Further features and advantages of the invention result from the following detailed description of an embodiment of the invention, from the claims as well as based on the Figures of the drawing which illustrate details important to the invention. The various features can be realized individually by themselves or several thereof in any combinations in variants of the invention. The features illustrated in the drawing are illustrated such that the particularities according to the invention can be made visible clearly.

[0027] FIG. 1 shows in a section illustration a filter system comprising a filter housing, only schematically illustrated, as well as a filter element arranged in the filter housing with a fiberglass-containing filter medium, wherein the filter system Includes a fiberglass barrier in the form of a wound body, which is embodied separate from the fiberglass-containing filter medium and is arranged fluidically downstream thereof.

[0028] FIG. 2 shows the filter system according to FIG. 1 in a section illustration and in the mounted state at a filter head.

[0029] FIG. 3 shows the wound body of the filter element according to FIG. 1 with partially unwound fiber nonwoven web in a partially perspective illustration.

[0030] FIG. 4 shows a bar diagram with illustration of the measured particle number of fiberglass particles contained in a fluid flowing through a fiberglass-containing filter medium, plotted against the maximum Feret diameter of the fiberglass particles.

[0031] FIG. 5 shows a bar diagram with illustration of the measured fiberglass particle number after filtration of the fiberglass particle-containing fluid by means of a fiberglass barrier according to FIG. 1, plotted against the maximum Feret diameter of the fiberglass particles.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0032] FIG. 1 shows a filter system 10 having a filter housing 12 and a filter element 14 that is arranged in the filter housing 12. The filter housing 12 included a housing pot 16 with an annular cover 18 that is crimped onto the housing pot 16 and at which an annular sealing element 20 is held. The filter housing 12 includes here an inlet with a plurality of inlet openings 22 and a centrally arranged outlet 24 for a fluid to be filtered, in particular fuel or oil.

[0033] The filter element 14 is embodied here in an exemplary fashion as a round filter element and includes a fiberglass-containing filter medium 26. In other words, the fiberglass-containing filter medium 26 can comprise fiberglass or be comprised as a whole of fiberglass. The fiberglass-containing filter medium 26 is arranged relative to the longitudinal axis 28 of the filter element 14 in an annular shape and can be folded, for example, in a star shape. The fiberglass-containing filter medium 26 is arranged here between a first end disk 13 and a second end disk 32 of the filter element 14. The fiberglass-containing filter medium 26 can be glued or welded to the two end disks 30, 32 or can be arranged, held by being embedded, in the material of the two end disks 30, 32 in order to ensure a fluid-tight connection of the fiberglass-containing filter medium 26 to the end disks 30, 32.

[0034] Caused by manufacture, fiberglass particles can be discharged from the fiberglass-containing filter medium 26 and can thus contaminate the fluid filtered by the fiberglass-containing filter medium 26 at the clean side of the filter element 14. An individual fiberglass particle 38 is illustrated in FIG. 1 disproportionately large for illustration purposes. It should be noted that the fiberglass particles 38 in reality in longitudinal direction can comprise a length of up to several millimeters and an (average) thickness, measured transversely to the longitudinal direction, of more than 10 m.

[0035] The filter element 14 Includes in the embodiment illustrated in FIG. 1 a fiberglass barrier that is embodied as a wound body 40. The wound body 40 is arranged fluidically downstream of the fiberglass-containing filter medium 26 in order to prevent an undesirable discharge of fiberglass particles 38 from the filter element 14 and thus out of the outlet 24 of the filter housing 12. The wound body 40 is presently embodied as an integral component of the filter element 14 and forms therewith a common component unit that can be handled jointly. The wound body 40 is arranged here on a support body 42 in the form of a grid-shaped central tube 44 of the filter element 14 as it serves in conventional filter elements 14 for reinforcement of the filter element 14 and/or radial inward support of the fiberglass-containing filter medium 26.

[0036] The wound body 40 includes preferably a plurality of windings 46 of a filter material 48. The maximum winding thickness d of the wound body 40 in each case amounts to between 0.1 millimeter and 1.5 millimeter, wherein an individual layer of the filter material 48 as a function of the number of windings 46 of the filter material 48 amounts to between 0.1 millimeter and 1.5 millimeter. The wound body 40 includes in this context between one and four, here two windings 46 of the filter material 48, for example.

[0037] The fiberglass-containing filter medium 26 can be supported at the central tube 44 by means of the wound body 40 in a radial direction in relation to the longitudinal axis 28 of the filter element 14. Alternatively, between the fiberglass-containing filter medium 26 and the wound body 40, a gap 50even though only smallcan be formed which surrounds the wound body preferably completely in a radial direction in relation to the longitudinal axis 28. In the latter case, the fiberglass medium 26 is arranged, at least in the state without pressure loading, spaced apart from the wound body 40 in the radial direction. The wound body 40 can be flowed through in the radial direction in relation to the longitudinal axis 28 of the filter element 14 by the filtered fluid and can be integrated into the material of at least one, preferably of both end disks 30, 32 of the filter element 14, in particular embedded, but can also be glued or welded thereto.

[0038] In FIG. 2, the filter system 10 is shown in a section illustration and in a suspended mounted state at the filter head 51. The filter head 51 serves in a generally known manner to supply the fluid to be filtered to the filter system 10 and to guide the fluid that has been filtered by means of the filter system 10 away from the filter system 10. Due to the annular sealing element 22, a sufficient seal-tight seat of the filter system 10 at the filter head 51 is ensured. It is understood that the filter system 10 can also be designed for a so-called upright mounting at the filter head 51.

[0039] FIG. 3 shows the support body 42 embodied as a central tube 44 with the wound body 40, immediately wound thereon, of the filter element 14 according to FIG. 1 in a partial detail illustration and with partially unwound filter material 48. The filter material 48 is designed here as a nonwoven of so-called meltblown fibers. Alternatively, the filter material 48 of the wound body can be designed as a knit material, knotted material, or as a woven material, for example, in so-called sateen, linen or twill weave.

[0040] The retention capacity of the wound body 40 with regard to fiberglass fibers 38 (FIG. 1) substantially depends on the average pore size 52 of the filter material 48 as well as the number of the windings 46 of the filter material 48 on the support body 42. The average pore size 52 of the filter material 48 is here larger than an average diameter (not shown in the Figures) of the fiberglass particles 38 to be retained. In this way, the flow resistance of the wound body 40 for the fluid can be minimized. The rigid fiberglass particle 38, due to its inherent bending stiffness, in general cannot be deformed even at a high flow rate of the fluid to be filtered in such a way that it could pass the pore structure and the pores of the individual wound body layers or windings 46 which pores are arranged at least partially displaced relative to each other.

[0041] In most technical applications, fiberglass particles that are larger than 200 m are particularly critical, particularly because they can cause damage at devices which are arranged fluidically downstream of the filter system. In the automotive sector, this concerns, for example, the high-pressure injection pump of an internal combustion engine, the injectors as well as the internal combustion engine itself.

[0042] In FIG. 4, the number of fiberglass particles that has been measured in a test set-up without use of a barrier layer in a predetermined volume of a fluid that has been passed through a fiberglass-containing filter medium 26 (FIG. 1), established in fuel filtration, as a function of the maximum particle size L (FIG. 1) of the fiberglass fibers 38. The particle size L is here the maximum Feret diameter that has been determined by measuring technology and, for reasons of illustration in FIG. 4, is shown divided into particle fractions. The fuel contained more than 900 fiberglass particles with a size between 50 m and 100 m and in total still more than 300 fiberglass particles larger than 200 m.

[0043] The average pore size of the wound body 40 (FIG. 1) according to the invention is selected such that fiberglass particles with a size of more than 200 m according to the diagram illustrated in FIG. 5 are completely retained and fiberglass particles 38 with a length between 50 m and 200 m are filtered out by more than 95% from the fluid. Accordingly, a large proportion of the aforementioned secondary damages at devices which are arranged fluidically downstream of the filter element/filter system can be avoided. The wound body 40 which serves as a fiberglass barrier can be arranged, according to an embodiment which is not illustrated in detail in the drawing, also on a support body 42 that is embodied as an integral component of the filter housing 16 (FIG. 1). In particular, the support body 42 can be designed in the form of a central tube 44 which is connected as one piece together with the filter housing 12, i.e., the housing pot 16 or the (annular) cover 20. When the filter element is arranged in its predetermined mounted position in the filter housing, the support body 42 extends with the wound body 40 wound thereon at least in sections in axial direction into the filter element 14. When the filter element 14 is exchanged, the wound body 40 together with the support body remains at the filter housing 12. The wound body 40 includes in this context a structure which has been described above in connection with FIG. 3.