Filter Element With Magnetic Array

Abstract

A filter for removing ferrous particles from a fluid. The filter has an outer filter housing and a non-ferrous liner inside the housing. A plurality of magnets are longitudinally extended at intervals outside the liner. An insert inside the liner imparting a directional flow to the fluid inside the filter whereby ferrous particles in the fluid are trapped by the magnets and held against the non-ferrous line.

Claims

1. A filter for removing ferrous particles from a fluid, comprising: (a) a filter housing; (b) a non-ferrous liner inside the housing; (c) a plurality of magnets longitudinally extended at intervals outside the liner; and (d) an insert inside the liner for imparting a directional flow to the fluid inside the filter.

2. A filter as defined in claim 1, wherein the magnets are placed outside of the filter housing.

3. A filter as defined in claim 1, wherein the magnets are placed inside of the filter housing.

4. A filter as defined in claim 3, wherein the liner has an opening to allow fluid pressure to equalize on either side of the liner.

5. A filter as defined in claim 1, wherein the magnets are arranged in cylindrical arrays.

6. A filter as defined in claim 5, wherein a plurality of said cylindrical arrays of magnets are stacked along the length of the filter.

7. A filter as defined in claim 1, wherein the insert comprises a surface that induces vortical flow to the fluid as it moves through the filter.

8. A filter as defined in claim 7, wherein the surface comprises helical flighting.

9. A filter as defined in claim 1, wherein the insert comprises an axial return tube for directing filtered fluid outside of the filter.

10. A filter system, comprising a pair of filters as defined in claim 1 arranged in parallel and a valve for isolating one of the filters from fluid flow while the other filter remains operational.

11. A filter system, comprising a conventional standard media filter placed in a fluid flow line upstream of a filter as defined in claim 1.

12. A filter system, comprising a conventional standard media filter placed in a fluid flow line downstream of a filter as defined in claim 1.

13. A filter as defined in claim 1, wherein the insert comprises a plurality of plates that induce an alternating step-flow path to the fluid as it moves through the filter.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0011] FIG. 1 is a cross-sectional view of a filter element of the present invention wherein an insert which induces a vortex in the fluid flow is used.

[0012] FIG. 2 is an exploded view of the embodiment of FIG. 1.

[0013] FIG. 3 is a perspective view of a filter element of the present invention wherein a spiral-shaped insert is used to direct the fluid in a spiral flow pattern inside the filter element.

[0014] FIG. 4 is an exploded view of the embodiment of FIG. 3.

[0015] FIG. 5 is a cross-sectional view of the embodiment of FIG. 3.

[0016] FIGS. 6a and 6b are alternative arrangements of magnets of the filter elements of the present invention.

[0017] FIG. 7a is a side view of an alternative embodiment of the filter of a filter of the present invention; FIG. 7b is a cross-sectional view of the filter of FIG. 7a; FIG. 7c is a partially exploded view of the filter of FIG. 7a wherein the outer pressure wall has been removed to show the interior of the filter.

DESCRIPTION OF THE INVENTION

[0018] Illustrated in FIGS. 1 and 2, generally at 10, is a preferred embodiment of a filter element of the present invention. The filter element 10 includes a cylindrical filter housing 12 to which is affixed a top plate 14 and a bottom plate 16. A non-ferrous liner 18 is received in a close fit inside the housing 12. An insert 20 extends from the top plate 14 axially down the housing 12, terminating above the bottom plate 16. The insert 20 includes a central return tube 22. Fluid is directed into the filter element 10 through a port 24 in the top plate 14 and is returned to the exterior of the filter element 10 via the return tube 22. The insert 20 preferably has a plurality of radially extended plates 26 that act to introduce a flow pattern to fluid inside the filter element 10. Encircling the exterior of the filter housing 12 are a plurality of annular rings of magnets 28 which will act to attract ferrous contaminants present in the fluid where they will be held against the liner 18.

[0019] In certain embodiments, it may be desirable to induce a predetermined flow pattern of the fluid inside the filter element 10 so as to improve the filtering efficiency of the filter element 10. For example, inducing a vortex in the fluid around the longitudinal axis will increase the residence time of the fluid inside the filter element 10 and will also cause a centripetal force that will urge the higher density ferrous contaminants toward the liner 18 and arrays of magnets 28. The vortex can be induced by angling of the port 24 and by selecting a shape and placement of the plates 26 that will help maintain the vortical flow.

[0020] Illustrated in FIGS. 3 and 4, generally at 110 is an alternative embodiment of the present invention filter element. The filter element 110 includes a cylindrical filter housing 112 to which is affixed a top plate 114 and a bottom plate 116. A non-ferrous liner 118 is received in a close fit inside the housing 112. An insert 120 extends from the top plate 114 axially down the housing 112, terminating above the bottom plate 116. The insert 120 includes a central return tube 122. Fluid is directed into the filter element 110 through a port 124 in the top plate 114 and is returned to the exterior of the filter element 110 via the return tube 122. The insert 120 has helical fighting 126 to induce a spiral flow pattern to fluid inside the filter element 110. Encircling the exterior of the filter housing 112 are a plurality of annular rings of magnets 128 which will act to attract ferrous contaminants present in the fluid where they will be held against the liner 118. The helical fighting 126 acts to increase the residence time of fluid inside the filter element 110 and creates a centripetal force that will urge higher density ferrous contaminants into proximity of the liner 118 and magnet arrays 128.

[0021] A further preferred embodiment is illustrated generally at 210 in FIG. 5. It is similar to filter element 110 except that the magnet arrays 228, including individual magnets 130, have been placed inside the filter housing 112 but outside the non-ferrous liner 118. By placing the magnet arrays 228 inside the filter housing 112, any shielding effect of the filter housing 112 will be eliminated and the capture of ferrous contaminants improved. If desired, a plurality of openings can be created in the liner 118, preferably not in the areas of the magnets 130, to allow the pressure to equalize on either side of the liner 118.

[0022] The individual magnets 130 may be arranged in at least two different ways. The magnets may be arranged in adjacent pairs of alternating polarity, as illustrated in FIG. 6a and similar to that described in U.S. Pat. No. 7,662,282 (which is incorporated herein in its entirety by this reference), or as individual magnets spaced apart from each other with alternate magnets having opposite polarity, as illustrated in FIG. 6b.

[0023] In certain applications, it may be preferable to provide a port in the bottom plate 16, 116 through which compressed gas can be directed into the filter housing 12, 112, to assist in purging fluid from the filter 10, 110.

[0024] An alternative embodiment is illustrated in FIGS. 7a-7c, wherein the filter is illustrated generally at 210. The filter 210 includes a filter housing or pressure vessel wall 212 to which is affixed a top plate 214 and a bottom plate 216. A non-ferrous liner 218 is received in a close fit inside the housing 212. An insert 220 is comprised of a central, closed spacer tube 222 about which are arranged in a vertically spaced, stacked relationship a plurality of spacer plates 224. Each spacer plate 224 has a partial annular shape wherein a portion of an otherwise annular piece of material has been removed, as at 226 in FIG. 7c. The arrangement of the removed sections 226 alternate from one side of the filter 210 for odd-numbered spacer plates 224 to the opposite side of the filter 210 for even-numbered spacer plates 224.

[0025] Oil to be filtered is introduced into the filter 210 at inlet 230 and is removed from the filter 210 at outlet 232. The path of the oil inside the filter 210 is determined by the arrangement of the removed sections 226 of the stacked spacer plates 224. Since the removed sections 226 alternate sides of the filter 210 as described, the oil is forced to go from one side of the filter 210 to the other side as it encounters each spacer plate 224. The path of the oil through the filter 210 is thus increased as is the residence time it spends near the circumferential periphery of the filter 210. The oil thus has a stepped flow path in contrast to the spiral flow path of the filter 10. A series of magnet arrays 228, similar to those described in the other embodiments are arranged outside the filter housing 212 and will serve to trap ferrous contaminants against the non-ferrous liner 218. An advantage of the embodiment filter 210 is that the stacked spacer plates can be easily and inexpensively manufactured, for example, by laser cutting.

[0026] The foregoing description and drawings comprise illustrative embodiments of the present inventions. The foregoing embodiments and the methods described herein may vary based on the ability, experience, and preference of those skilled in the art. Merely listing the steps of the method in a certain order does not constitute any limitation on the order of the steps of the method. The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except insofar as the claims are so limited. Those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.