Ovate tubular filter cartridges and filter systems using the same

Patent metadata

Field	Value
Publication number	US-9630134-B2
Application number	US-201414211362-A
Country	US
Kind code	B2
Filing date	Mar 14, 2014
Priority date	Mar 15, 2013
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

Filter cartridges including tubular filter media having ovate cross-sections and filter systems using the ovate tubular filter cartridges are described herein. The inner perimeters of the ovate cross-sections of one or more of the filter cartridges may be asymmetric, i.e., the inner perimeters of the cross-sections of the tubular filter media in the filter cartridges may have no lines about which they are symmetric. The inner perimeters of the ovate cross-sections of the tubular filter media in one or more of the filter cartridges may have only one line of symmetry.

First claim

What is claimed is:

1. A filter cartridge configured to improve particulate loading in an air filter system employing pulse-cleaning, the filter cartridge comprising:
tubular filter media defining an interior surface facing an interior volume of the filter cartridge and an exterior surface facing away from the interior volume, wherein the tubular filter media defines a tubular filter media length measured along a tube axis extending from a first end to a second end of the tubular filter media;
a filter cartridge housing comprising a first end cap at the first end of the tubular filter media and a second end cap at the second end of the tubular filter media;
wherein, in a cross-section taken transverse to the tube axis at any location along a majority of the tubular filter media length, the interior surface of the tubular filter media defines an inner perimeter comprising a shape configured to improve pulse cleaning of a filter cartridge that also offers improved particulate loading;
wherein the cross-section comprises a maximum height (Hmax) measured between a top point and a bottom point, wherein the top point and the bottom point are located on the inner perimeter and an axis of maximum height that extends across the cross-section at a location and in an orientation such that the top point and the bottom point are points on the inner perimeter that are furthest apart from each other along any straight line extending across the cross-section;
wherein the cross-section comprises a maximum width (Wmax) measured between a first point and a second point located on the inner perimeter and on an axis of maximum width, wherein the axis of maximum width is located along a straight line perpendicular to the axis of maximum height, and wherein the axis of maximum width intersects the axis of maximum height at a bottom axis intersection point where the first point and the second point are furthest from each other on any straight line perpendicular to the axis of maximum height;
wherein the bottom axis intersection point does not bisect the maximum height of the cross-section as measured between the top and bottom points;
wherein an inscribed circle located within the inner perimeter of the cross-section defines a maximum radial gap between the circle and the inner perimeter that is 0.25 or less of a diameter of the inscribed circle to enhance pulse cleaning of the air filter, wherein the maximum radial gap is measured along a radial line extending through a center of the inscribed circle;
wherein the cross-section comprises a bottom section height measured along the axis of maximum height from the bottom point to the bottom axis intersection point, and wherein the bottom section height is greater than zero and less than or equal to 0.4 of the maximum height measured along the axis of maximum height from the top point to the bottom point;
wherein the inner perimeter of the cross-section comprises a bottom perimeter section containing the bottom point, wherein the bottom perimeter section comprises a bottom perimeter section length measured along the inner perimeter from the first point to the second point;
wherein the inner perimeter of the cross-section comprises a top perimeter section containing the top point, wherein the top perimeter section extends from a first end to a second end, wherein the first end is located on the inner perimeter between the first point and the top point and the second end is located on the inner perimeter between the second point and the top point, wherein first end and the second end of the top perimeter section are the points at which a top perimeter section line intersects the inner perimeter, and wherein the top perimeter section comprises a top perimeter section length measured along the inner perimeter from the first end to the second end;
wherein the top perimeter section line is a straight line that is perpendicular to the axis of maximum height and that intersects the axis of maximum height at a top axis intersection point, wherein the cross-section comprises a top section height measured along the axis of maximum height from the top axis intersection point to the top point on the inner perimeter;
wherein the top section height is equal to the bottom section height;
and wherein the bottom perimeter section length is greater than the top perimeter section length such that more of the tubular filter media faces downward than upward when the filter cartridge is oriented with the bottom perimeter facing downward.

2. A filter cartridge according to claim 1 , wherein the bottom section height is greater than or equal to 0.1 of the maximum height.

3. A filter cartridge according to claim 1 , wherein the bottom perimeter section length is 1.2 or more times greater than the top perimeter section length.

4. A filter cartridge according to claim 1 , wherein the bottom perimeter section length is 2 or more times greater than the top perimeter section length.

5. A filter cartridge according to claim 1 , wherein the entire bottom perimeter section is continuously curved from the first point to the second point.

6. A filter cartridge according to claim 1 , wherein no section of the inner perimeter between the first point and the second point lies on a straight line for a distance of more than 1 centimeter.

7. A filter cartridge according to claim 1 , wherein the axis of maximum height does not lie on a line of symmetry of the inner perimeter of the cross-section.

8. A filter cartridge according to claim 1 , wherein the inner perimeter of the cross-section defines only one line of symmetry.

9. A filter cartridge according to claim 1 , wherein the inner perimeter of the cross-section defines only one line of symmetry, and wherein the axis of maximum height is coincident with the line of symmetry.

10. A filter cartridge according to claim 1 , wherein the inner perimeter of the cross-section is asymmetric.

11. A filter cartridge according to claim 1 , wherein the inscribed circle occupies less than all and 60% or more of an inner area defined by the inner perimeter.

12. A filter cartridge according to claim 1 , wherein the cross-section is taken transverse to the tube axis at any location along 10% or more of the tubular filter media length.

13. A filter cartridge according to claim 1 , wherein the tubular filter media comprises pleats extending between the interior surface and the exterior surface.

14. A filter cartridge according to claim 1 , wherein the inscribed circle located within the inner perimeter of the cross-section occupies 70% or more of the inner area defined by the inner perimeter.

15. A filter cartridge according to claim 1 , wherein the inscribed circle located within the inner perimeter of the cross-section occupies 80% or more of the inner area defined by the inner perimeter.

16. A filter cartridge configured to improve particulate loading in an air filter system employing pulse-cleaning, the filter cartridge comprising:
tubular filter media defining an interior surface facing an interior volume of the filter cartridge and an exterior surface facing away from the interior volume, wherein the tubular filter media defines a tubular filter media length measured along a tube axis extending from a first end to a second end of the tubular filter media;
a filter cartridge housing comprising a first end cap at the first end of the tubular filter media and a second end cap at the second end of the tubular filter media;
wherein, in a cross-section taken transverse to the tube axis at any location along a majority of the tubular filter media length, the interior surface of the

Assignees

• Donaldson Co Inc

Inventors

• Raether Thomas D

Classifications

• B01D2275/208

  Oval shape · CPC title

• B01D2275/206

  Special forms, e.g. adapted to a certain housing · CPC title

• B01D46/521

  using folded, pleated material · CPC title

• B01D2275/207

  Triangular shape · CPC title

• B01D46/2411 Primary

  Filter cartridges · CPC title