BACKGROUND
Pleated filter media, such as collapsible pleated mechanical media (ESPM) filters, occupy substantially less space in their collapsed state, compared to equivalent cartridge configurations. Thus, they are easier to store and ship, and consequently have lower storage and shipping costs. However, collapsible filters are substantially less user-friendly than equivalent cartridge-style filters, which can be easily inserted into and removed from the filter enclosure with only minimal user interaction. In contrast, collapsible filters can require assembly by the end user before they are ready to be installed into the filter housing. For example, one such air cleaner includes an inner housing, an outer housing, and a door. Effort is required to ensure that, after installation, the filter forms an effective seal in the filter enclosure such that air must pass through the filter and not around the filter. Thus, there exists a need for a collapsible filter that forms an effective seal with the filter enclosure with minimal effort by the end user.
SUMMARY OF THE INVENTION
The present disclosure is directed to an air filter for use in a forced-air system that forms an effective seal with the filter enclosure. A filter is designed for an air cleaner that has a filter enclosure that has a width W1, and top and bottom channels. The air cleaner is adapted to direct air to flow through the filter enclosure from an upstream to a downstream direction. The filter includes a flexible support member with first and second side edges. The support member has a width W2 that is substantially equal to but less than W1. The filter also includes a filter media layer connected to and covering at least one side of the support member and has an unfolded width W3 that is greater than the width W2 of the support member, such that the filter media, when unfolded, extends beyond the first and second side edges of the support member to form filter media skirts. The filter media skirts are folded over the respective first and second side edges of the support member to cover the side edges and form a filter media cushion on the side edges of the filter. The filter with folded over skirts has a width W4 that is equal to or, more preferably, slightly greater than the width W1 of the enclosure. When the filter is positioned in the enclosure, the filter media cushions conform to the enclosure thereby forming an effective seal.
The filter is configured to be positioned in the enclosure with the support member downstream from the filter media with respect to the direction of airflow from the filter media layer. Also, the filter is pleated and collapsible.
Finally, a pair of end caps can be attached to a top and a bottom end portions of the flexible metal support member. The end caps are configured to engage the top and the bottom channels of the enclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric exploded view of a frame and a first embodiment of a filter according to the invention.
FIG. 2 is a longitudinal cross-sectional view of the frame and filter of FIG. 1.
FIG. 3 is a transverse cross-section of the first embodiment of the filter taken along line 3-3 of FIG. 2.
FIG. 4 is an enlarged detail of the frame and filter taken along line 4-4 of FIG. 3.
FIG. 5A is a plan view of a support member and the filter media layer.
FIG. 5B is a plan view of the filter media layer partially folded over the support member.
FIG. 5C is a plan view of the filter media layer folded over the support member.
DETAILED DESCRIPTION
Referring to FIG. 1, an air cleaner is generally designated 10 and includes a frame enclosure 12 and a filter 14. The frame enclosure 12 includes a top wall 16, a bottom wall 18, a rear wall 20, and a reinforcement member 22. The enclosure 12 has an upstream air-inlet opening 24 and a downstream air-outlet opening 26. In addition, the enclosure 12 has a filter opening 28 that is opposite the rear wall 20. The enclosure 12 can further include guide tracks 30 adjacent to the top wall 16 and the bottom wall 18 and that extend from at or near the rear wall 20 to at or near the filter opening 28. A door 32 is attachable to the frame enclosure 12 to close the filter opening 28.
Filter 14 is preferably a pleated filter media such as a collapsible extended surface pleated mechanical media filter (ESPM) type such that the filter occupies substantially less space in its collapsed stated than in its expanded state. Typically, filter 14 is transported and sold in a collapsed state. At the time of installation, the filter is expanded, as shown in FIG. 1. The filter 14 is configured to be insertable into the frame enclosure 12 through the filter opening 28. When inserted, the filter 14 extends between the top and bottom walls, 16 and 18 respectively, between the rear wall 20 and the filter opening 28, and between the air-inlet opening 24 and the air-outlet opening 26. Consequently, when the door 32 is closed, air can be directed to flow through the air cleaner 10 from the air-inlet opening 24, through the filter 14, and then exiting through the air outlet-opening 26.
As shown in FIGS. 1-3, filter 14 includes a filter media layer 34 and flexible support member 36. As is well known in the art, the filter media may be made of non-woven natural or synthetic fibers capable of extracting impurities from the air. However, the filter media layer 34 can be made of other known or later-developed materials.
The support member 36 is porous and flexible and is preferably fabricated from slit and expanded metal foil. However, the support member 36 could be made of plastic or other material. The support member 36 is more rigid than the filter media layer 34 and is preferably positioned on the downstream side of the filter media layer 34 in a direction of airflow as shown in FIG. 3. The filter support member 36 provides support to the filter media layer 34 to maintain a generally pleated shape of the filter 14. As shown in FIGS. 5A-5C, the filter support member 36 has side edges 40, 41, a top edge 42, a bottom edge 43, a first side surface 44, and a second side surface 46.
Referring back to FIG. 3, the filter 14 preferably includes a set of end caps 48 at the top and bottom ends, 50 and 52 respectively, of the filter 14. Each end cap 48 is attached to the filter media layer 34, the filter support member 36, or both. Each end cap 48 is configured to engage the guide tracks 30, thereby securing the end caps and the filter 14 in the enclosure 12.
FIG. 2 shows the filter 14 installed in the enclosure 12. The enclosure 12 has an interior width of W1, measured as the distance from the interior surface of the rear wall 20 to the interior surface of the door 32 when the door is closed.
The filter 14 can optionally include one or more pleat spacer members 54 that extend between the end caps 48 and is connected to the end caps and the pleat edges 38. The spacer member 54 functions to maintain uniform pleat spacing and provides structural support to the filter 14. Multiple spacer members 54 can be provided on one or both sides of the filter 14.
Turning now to FIGS. 5A-5C, the filter media layer 34 and the support member 36 are shown. In FIG. 5A, the unpleated, flat support member 36 is shown attached to the flat, unpleated filter media layer 34. The support member 36 has a width W2 measured as the distance between side edges 40 and 41 of the filter support member 36. The filter media layer 34 includes side edges 56 and has a width W3 measured as the distance between the side edges of the filter media layer. The width W3 is greater than W2. Preferably, the support member 36 is centered on the filter media layer 34 in the width direction. Preferably, the filter media layer 34 completely covers one side of the support member 36. As shown in FIG. 5A, the filter media layer 34 includes skirt portions 58, which are portions of the filter media layer that extend beyond the side edges 40 and 41 of the support member 36.
As shown in FIGS. 5B-5C, the skirt portions 58 of the filter media layer 34 are folded over the side edges 40, 41 of the support member 36. The skirt portion 58 covers and is folded over the side edges 40, 41 to a portion of a second side 46 of the support member 36. Preferably, the skirts 58 are folded over the side edges 40, 41 and are adhered or otherwise attached to the downstream surface of the support member 36. However, it is not necessary that the skirts 58 be attached to the second side 46 of the support member 36. A filter media cushion is thereby formed covering the side edges 40, 41 of the support member 36. The filter media cushion 60 prevents the end user from coming into contact with the side edges 40, 41 of the support member 36, which can be sharp and cause injury. The filter media cushion 60 also helps form an effective seal between the filter 14 and the enclosure 12, as described below.
The filter 14 has a width W4 measured as the distance between the filter media cushions 60. The width W4 should be equal to or greater than the width W1 of the enclosure 12 and greater than the width W2 of the support member 36. In other words:
W2≦W1
W1≦W4
W2≦W4
Since the width W4 of the filter 14 is equal to or greater than the width W1 of the enclosure 12, the filter 14 may closely fit within or be compressed in a width direction in order to fit into the enclosure 12. Specifically, cushions 60 represents the difference between W2 and W4. In other words, the difference between the width W4 and the width W2 is the added dimension of the one or more filter media cushions 60. As shown in FIG. 4, when the filter 14 is inserted into the enclosure 12, the filter media cushion 60 forms a compression point 62 where the filter media cushion contacts the rear wall surface 20 and/or the door 32. The support member 36 being more rigid than the filter media layer 34 is less likely to deform. Because of the seal formed at point 62, air flowing through the ductwork is directed to pass through the filter 14.
As shown in FIG. 4, the filter media layer 34 is folded over the side edges 40, 41 of the support member 36. The filter media cushion 60 covers the side edges 40, 41 of the support member 36. As the filter 14 is inserted into the enclosure 12, the filter media cushion 60 will conform to the rear wall 20, compressing the filter media at point 62. This compression point 62 allows the filter 14 to form an effective seal with the enclosure 12.
It should be appreciated that the term “effective seal” encompasses exemplary embodiments where air flowing from the air-inlet opening 24 to the air-outlet opening 26 directed primarily through the filter 14, rather than around it. It should be appreciated that the term “effective seal” does not necessarily mean that no air flows between around the filter media.
While only certain embodiments have been set forth, alternative embodiments and various modifications will be apparent from the above description to those skilled in the art. These and other alternatives are considered equivalents and within the spirit of scope of the present invention.
Patent Application
20140150385
