CA2692316A1

CA2692316A1 - Magnetic filter elements

Info

Publication number: CA2692316A1
Application number: CA 2692316
Authority: CA
Inventors: Roger L. Marchand; Douglas J. Tschetter
Original assignee: Bay6 Solutions Inc
Current assignee: Bay6 Solutions Inc
Priority date: 2010-02-12
Filing date: 2010-02-12
Publication date: 2011-08-12

Abstract

A magnetic filter element has an elongate non-magnetic housing and a series of magnets arranged in a column within the housing. Each magnet has a north pole and a south pole. The plurality of magnets is arranged with the north poles adjacent to the south poles of adjacent magnets. Non-magnetic spacer elements separate the plurality of magnets in the column.

Description

TITLE
[0001] Magnetic filter elements FIELD

[0002] This relates to a magnetic filter element.
BACKGROUND

[0003] United States patent no. 6,143,171 (Van Aarsen) entitled "Magnetic device for treatment of fluids" describes a magnetic device that is used to remove ferrous particles from a fluid. The magnetic device has a series of magnets arranged in a column with like poles facing one another and separated by magnetically permeable discs.

SUMMARY

[0004] There is provided a magnetic filter element, comprising an elongate non-magnetic housing and a series of magnets arranged in a column within the housing. Each magnet has a north pole and a south pole. The plurality of magnets is arranged with the north poles adjacent to the south poles of adjacent magnets. Non-magnetic spacer elements separate the plurality of magnets in the column.

[0005] The non-magnetic housing may comprise a non-magnetic end cap that extends outward from the last magnet in the column such that the end cap forms a non-magnetic section at the end of the housing. The series of magnets may be spaced from a mounting end of the housing to provide a non-magnetic section at the mounting end of the housing.

[0006] The non-magnetic housing comprises a flange at a mounting end of the housing.
The mounting end of the housing may comprise external threads adjacent to the flange.

[0007] A dipole moment of each magnet may be parallel or perpendicular to the housing.
BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to be in any way limiting, wherein:

FIG. 1 is a side elevation view in section of a magnetic filter element.
FIG. 2 is a side elevation view in section of an alternative magnetic filter element.
FIG. 3 and 4 are side elevation views of alternative housings.
FIG. 5 is a perspective view of a series of magnets.
FIG. 6 and 7 are side elevation views of alternative non-magnetic barriers.
DETAILED DESCRIPTION

[0009] A magnetic filter element, generally identified by reference numeral 10, will now be described with reference to FIG. 1 through 7.
Structure and Relationship of Parts:
[0010] Referring to FIG. 1, magnetic filter element 10 has an elongate non-magnetic housing 12 and a series of magnets 14 arranged in a column within housing 12.
Preferably, magnets 14 are rare earth magnets, such as NdFeB magnets, or other strong magnets. As shown in the depicted embodiment, magnets 14 may be sized to fit closely within housing 12.
Preferably, housing 12 is a cylindrical housing, and, referring to FIG. 4, magnets 14 are shorter cylinders or puck shaped to fit within housing 12. Referring to FIG.
1, each magnet 14 has a north pole 16 and a south pole 18. Magnets 14 are arranged such that north poles 16 and south poles 18 of adjacent magnets 14 are adjacent, and are separated by a non-magnetic barrier 20. Magnets 14 may be oriented such that their dipole moments are parallel to housing 12 as shown in FIG. 1, such that there is only one north/south interface on each side of magnets 14. In other words, if each magnet 14 is puck shaped, magnet 14 varies from north to south along its height. Alternatively, referring to FIG. 2, the dipole moment of each magnet may be perpendicular to housing 12, such that magnets 14 vary along the width rather than their height. This results in two north/south interfaces for each side of magnets 14, and results in a more complex magnetic field pattern.

[0011] When opposite magnetic poles are adjacent, the magnetic field lines are densely positioned around the interface. This can be contrasted with magnetic field lines when like poles are adjacent, which extend perpendicular to each other out to infinity.
Opposite poles result in a magnetic attraction that is very strong close to the interface of the magnets, but tapers off quickly as one moves away from that interface. This can be used to provide a strong holding force on ferrous debris that is encountered in a liquid.
However, the debris must get quite close to filter element 10 to be affected. As these opposed poles are separated, such as by non-magnetic barrier 20, the field lines move outward, such that the strength of the magnetic attraction close to the magnet is reduced somewhat, but extends further outward.
Thus, there is a trade-off between the reach of the magnetic attraction, and the strength of the magnetic attraction. The size of the non-magnetic barrier 20 can be used to select the desired magnetic field. The design described herein is particularly useful in situations where a moving fluid is to be filtered, such as in engine lubrication systems, hydraulic equipment or other mechanical devices.

[0012] Non-magnetic barrier 20 may take different forms. For example, FIG. 6 shows a non-magnetic spacer element 21, such as a disc, which may be composed of various non-magnetic materials and may have various thicknesses. Alternatively, non-magnetic spacer element 20 may be formed from a fluid. FIG. 7 depicts how this may be done by providing magnets 14 with protrusions 22 on the end of each magnet 14. The space may then be filled with a non-magnetic gas or liquid. While protrusions 22 may be magnetic, the amount of magnetic material will be small enough to minimize their effect on the operation of filter element 10.

[0013] In other embodiments, filter element 10 preferably has non-magnetic portions at one or both ends. Referring to FIG. 1, non-magnetic housing 12 may have a non-magnetic end cap 24 that extends outward from the last magnet 14 in the column such that end cap 24 forms a non-magnetic section at the end of housing 12. This may be useful, for example, when cleaning a filter element, as the captured particles can be pushed toward the non-magnetic end where they are more easily removed. In addition, this may also help avoid inducing a magnetic dipole in the machinery that is close to end cap 24.
Similarly, there may be a non-magnetic portion at a mounting end 26 of housing 12 formed by a non-magnetic element 27.

[0014] In order to install filter element 10, non-magnetic housing 12 may have threads 28 at mounting end 26 as shown in FIG. 3, a flange 30 as shown in FIG. 4, or both. The embodiment in FIG. 3 may be threaded into an aperture, while the embodiment in FIG. 4 may be pin-connected into an aperture through holes 32.

Operation:

[0015] The embodiments shown in FIG.1 and 2 are assembled by providing a non-magnetic housing 12. Magnets 14 are inserted into housing 12 to form non-magnetic barriers 20 between each magnetic, and such that opposite poles are adjacent. End cap 24 and a non-magnetic element 27 are provided, and the entire structure may be held together by inserting a threaded rod 34. As shown in FIG. 5, magnets 14 preferably have a central aperture 35 to facilitate this. Referring to FIG. 3 and 4, to facilitate installation, housing 12 may have threads 28, a flange 30, or both. Element 10 may then be installed such that magnets 14 exert a force on magnetic particles and debris in a fluid. Magnetic filter element 10 is particularly useful for filtering moving fluids in relatively small spaces, and may be inserted through an aperture in a tank wall, such as in an engine lubrication system, hydraulic equipment or other mechanical devices.

[0016] To clean filter element 10, it is first removed from the fluid, and may be wiped clean by starting at the non-magnetic section at mounting end 26 and moving toward non-magnetic end cap 24. Alternatively, it may be pressure washed, or otherwise cleaned as will be recognized by those in the art.

[0017] In this patent document, the word "comprising" is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one element is present, unless the context clearly requires that there be one and only one of the elements.

[0018] The following claims are to be understood to include what is specifically illustrated and described above, what is conceptually equivalent, and what can be obviously substituted. Those skilled in the art will appreciate that various adaptations and modifications of the described embodiments can be configured without departing from the scope of the claims. The illustrated embodiments have been set forth only as examples and should not be taken as limiting the invention. It is to be understood that, within the scope of the following claims, the invention may be practiced other than as specifically illustrated and described.

Claims

1. A magnetic filter element, comprising:
an elongate non-magnetic housing;
a series of magnets arranged in a column within the housing, each magnet having a north pole and a south pole, the plurality of magnets being arranged with the north poles adjacent to the south poles of adjacent magnets; and non-magnetic barrier separating the plurality of magnets in the column.

2. The magnetic filter element of claim 1, wherein the non-magnetic housing comprises a non-magnetic end cap that extends outward from the last magnet in the column such that the end cap forms a non-magnetic section at the end of the housing.

3. The magnetic filter element of claim 1, wherein the series of magnets are spaced from a mounting end of the housing to provide a non-magnetic section at the mounting end of the housing.

4. The magnetic filter element of claim 1, wherein the non-magnetic housing comprises a flange at a mounting end of the housing.

5. The magnetic filter element of claim 3, wherein the mounting end of the housing comprises external threads adjacent to the flange.

6. The magnetic filter element of claim 1, wherein a dipole moment of each magnet is parallel to the housing.

7. The magnetic filter element of claim 1, wherein a dipole moment of each magnet is perpendicular to the housing.

8. The magnetic filter element of claim 1, wherein the non-magnetic barrier is a non-magnetic spacer element.

9. The magnetic filter element of claim 1, wherein the non-magnetic barrier is air.