FI129956B

FI129956B - Filter Assembly

Info

Publication number: FI129956B
Application number: FI20195361A
Authority: FI
Inventors: Samu Pöri; Tommi Lustig
Original assignee: Ilmastointipuhdistus Polu Oy
Priority date: 2019-05-03
Filing date: 2019-05-03
Publication date: 2022-11-30
Also published as: FI12708U1; SE545881C2; DE112020002239T5; SE2151471A1; FI20195361A1; FI12708Y1; WO2020225477A1

Abstract

The invention concerns a filter assembly (16), comprising a frame having a top and a bottom side. The frame (6) defines an aperture in which a bag -like insert of a filter material may be inserted. A first tape (9) of a fastener is attached to the outer side of the frame and running around the perimeter of the frame and a second tape (13) of a fastener attached to an upper portion of the insert. The insert is arranged to fit into the frame with its open upper portion bent over the frame to cover the top side of the frame and to mate the first and second fastener tapes with each other at an outer edge of the frame, to form a sealed joint when said tapes are fully engaged with each other.

Description

TITLE OF THE INVENTION

Filter Assembly

FIELD OF THE INVENTION

The present invention relates to air filters used in buildings. More specifically, the invention relates to cartridge type filters having a frame with a bag- like filter cloth arranged within the frame, which may be used as a unit to be inserted transversely in an air duct or the like.

BACKGROUND OF THE INVENTION

Fans or blowers are used along with ductwork to circulate air through a room or area of a building. The blower typically draws air from within the room through a return air duct and then — forces the air back into the room through a supply air duct. To heat or cool the air, the blower may also force or draw the air across a heat exchanger.

To prevent dust from accumulating on various equipment, and on the ductwork downstream of the blower in the return air duct, filters may be installed adjacent to the blower. Filters create a pressure drop that reduces the amount of airflow. To minimize the pressure drop, the cross- sectional area of the filter is usually increased by adding pleats to the filter cloth, installing the filter at an angle relative to the duct, or by forming the filter as an elongated bag that extends lengthwise into an air duct.

All filters must be cleaned or changed from time to time according to the maintenance cycle of the building. Used air duct filters, such as cartridge filters, are usually discarded and replaced by — new ones. Depending on the number of ducts and the blowers and their size, the number of replacement cartridges in one maintenance cycle may vary from one to hundreds. A typical filter = usually consists of a durable metal or plastic frame, with intermediate bars that form slots in one

N direction across the frame. In these slots, filter cloth bags are fastened between the intermediate = bars or otherwise, in a pleated fashion.

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£ 25 When a cartridge filter is discarded, also the metallic (or plastic) frame is thrown away. This, of = course, is a waste of resources. Individual filter bags are usually not intended to be removable e from the frames, and are attached to the frames by any means from underneath. Thus the frames = get dirty from the dust, debris and fatty substances (e.g. in a kitchen) that flows into a return

N duct, and they would need to be removed anyway.

There is thus a need for improvements in such maintenance work, in order to find a solution to the filter waste problem and to reduce the amount of work needed while performing filter changes.

The present invention aims to solve or alleviate these problems to a great extent. The invention is characterized by what is stated in the appended claims.

According to an aspect of the invention, a filter assembly is provided, that comprises: — a frame having a top and a bottom side and inner and outer edges, said inner edges of said frame defining an aperture, — a bag -like insert of a filter material having an open upper portion and at least one closed bottom portion, — a first tape of a fastener attached to the outer edge of said frame and running around the outer perimeter of the frame; — a second tape of a fastener attached to said upper portion of said insert.

The insert is arranged to fit into the aperture of said frame with the open upper portion bent over the frame to at least partly cover the top side of the frame. The first second tape is mated with the first fastener tape to form a sealed joint at the outer edge of the frame when the tapes are fully engaged with each other.

The structural element “tape” is here used to describe any elongate fastener aimed to form a sealed joint between two separate mating parts of a fastener. The word tape is thus meant to be understood broadly, as an attachable carrier of a fastener, or as an integral part of the fastener itself. A number of such exemplary tapes are disclosed, but it is clear to one skilled in the art = that any elongate fastener may be used in a manner claimed, without departing from the scope of

N the invention. 3 2 In some embodiments, the frame is provided with parallel intermediate bars across said aperture

T 25 that defines slots across the aperture. The insert may then have multiple bags formed in a pleated = fashion having a shared open upper portion and separate closed bottom portions. Each bag may e then be arranged to fit into one corresponding slot.

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N In some other embodiments, the frame may be provided with a grid of intermediate bars across the aperture defining a number of slots. In such cases, the insert may be formed with multiple bags having, for example, pointed and closed bottom portions and a shared open upper portion.

Each bag would then be designed to fit into one slot. A honeycomb-like structure of the grid may also be envisaged.

In some embodiments, the first tape is a first half of a zip fastener and the second tape is a second half of a zip fastener. The insert is arranged to fit into the frame with its open upper portion bent over the frame to at least partly cover the top side of the frame. The first and second zip fastener halves may be mated with each other to form a sealable zip fastener when pulling a slider provided in either one of said first or second zip fastener halves. The first and second zip fastener halves are mated with each other to form a sealable zip fastener when pulling a slider provided in either one of said first or second zip fastener halves. An insert pin on either one of the first and second zip fastener halves is inserted to a slider in the opposite zip fastener half, in order to form the sealable zip fastener.

According to some embodiments, the first tape is a first half of a so-called velcro fastener and said second tape is a second half of a velcro fastener. When the insert is arranged into the frame — with the open upper portion bent over the frame, the second tape will overlap the first tape to form a sealed joint when pressing said second tape to said first tape.

According to some embodiments, frame has the shape of a rectangle or a square, but of course also other shapes are possible, such as a circle. The frame is preferably made of a rigid material, such as wood, metal or a polymer material. However, flexible materials may also come into use, if the rigidity needed to retain the filter assembly in place is provided by other means.

In some embodiments, the intermediate bars across the aperture defining said slots are bars > attached to the frame by any means of fastening, such as nailing, gluing, welding, or by any form > of clip means, for example. Alternatively, the frame and the intermediate bars may be integral ro with and formed of the same material as the frame in one manufacturing process.

S 25 The invention offers considerable advantages. Apart from the obvious one of providing re-usable

E filter assembly frames, the frames are also always clean as at least the upper side of the frame is

O always covered by the filter material.

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2 Filter assemblies where the frame is made of wood may be disposed of in environmentally

N friendly ways by recycling, or they may be burned. Frames made of other materials may also be easily recycled, as the filter insert is removable.

No fastening of individual filter bags is needed, the whole filter insert is just dropped on top of the frame and secured with a zipper.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a filter assembly according to prior art;

Fig. 2 shows an exemplary frame of a filter assembly according to one embodiment of the invention;

Fig. 3 shows an exemplary insert of a filter assembly according to one embodiment of the invention;

Fig. 4 shows a first step of forming an inventive filter assembly according to one embodiment of the invention;

Fig. 5 shows a second step of forming an inventive filter assembly according to one embodiment of the invention; and

Fig. 6 shows a ready filter assembly according to one embodiment of the invention;

Fig. 7 shows a ready filter assembly according to another embodiment of the invention; — Fig. 8 shows the frame of a filter assembly according to a further embodiment of the invention.

DETAILED DESCRIPTION OF EMBODIMENTS

In Fig. 1 is shown a filter assembly 1 according to prior art with a frame 2, intermediate bars 4 and with one filter bag 3 attached 5 between each slot formed by the intermediate bars 4, or at o the edges, by an intermediate bar 4 and the frame 2. The air flow direction is from the upper or & 20 top side of the frame 2 downwards to the bags and the filtered air exits the filter through the 3 bottoms of the bags 3. 3

I In Fig. 2 is shown a square-shaped frame 6 of a filter assembly according to the present a - invention. The frame 6 has a top side 7a, outer edges 7b, inner edges 7c and a bottom side 7d o (not shown). The inner edges 7c defines an aperture having intermediate bars 8 across the

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N circumstances and reguirements of the filter assembly, the number of slots is a design criteria and may vary from 1 to any number upwards. Also shown is a first half 9 of a zip fastener with its tape attached to the outer side 7b of the frame 6 and running around the perimeter of the frame. The zip fastener half 9 is in this exemplary embodiment is provided with a slider 10.

In Fig. 3 is shown a bag -like insert 11 of a filter material. The insert has an open upper portion 14 shared by multiple bags formed in a pleated fashion, in this case the three bags 12. A second 5 half 13 of a zip with its tape is attached to and encircling the upper portion 14 of the insert. The material of the insert will depend on the application and may thus be made of a variety of materials, such as paper, cotton, polyester, etc.

An insert according to Fig. 3 may be arranged to fit into the aperture of the frame according to

Fig. 2 in a way that its open upper portion when bent over the frame will cover all of the top side 7a ofthe frame. The first second tape is mated with the first fastener tape to form a sealed joint at the outer edge 7b of the frame when the tapes are fully engaged with each other.

In Fig. 4 is shown a first step of forming the inventive filter assembly. An insert 11 as shown in

Fig. 3 is dropped in the direction of the arrow through a frame 6. In this example, each bag 12 of the insert 11 will occupy one of the slots A — C of Fig. 2.

In Fig. 5 is shown a second step of forming the inventive filter assembly, where the insert 11 is being fitted in a frame 6 with an edge of the insert upper portion 14 bent over the frame 6 to completely cover the top side 7a of the frame in fig. 2, all the way down to the outer edge 7b of the frame until the zipper. The first and second zip fastener halves 9, 13 are mated with each other in an ordinary fashion to form a closable zip fastener when pulling the slider 10, which — may be provided in either one of the first or second zip fastener halves.

Obviously, the mating of the first and second zip fastener halves 9, 13 with each other may be

O effected by an insert pin 15 on either one of the zip fastener halves, that is then inserted to the

N slider 10 in the opposite zip fastener half. 8 0 In Fig. 6 is shown a completed inventive filter assembly 16, where the slider 10 has been pulled z 25 around the upper portion 14 of the insert 11, thus closing the zipper formed by the first and * second halves 9, 13. As can be seen, the top of the frame 6 and intermediate bars 8 are now 3 covered by the insert 11. >

S In Fig. 7 is shown filter assembly 17 with an insert 20 according to another embodiment of the invention. Here a first tape 18 is a first half of a hook-and-loop fastener, i.e. a velcro fastener, and a second tape 19 is a second half of a velcro fastener. In a similar fashion as shown in Figs. 2 to 6, the insert 20 is arranged to fit into a frame with an open upper portion bent over the frame to cover the top side of the frame. The velcro tape halves will then overlap each other at the outer side of the frame to form a sealed joint when pressing the second tape 19 to the first tape 18.

In Fig. 8 is shown a square-shaped frame 24 of a filter assembly according to another embodiment of the invention. The frame 24 has a top side 21 and intermediate bars 22 and 23 defining a grid across the aperture of the frame. The grid defines a number of slots 25 (here nine slots). An insert (not shown) formed with multiple bags and having a shared open upper portion and separate closed bottom portions may then be inserted in the frame 24 with one bag iin each of the slots 25.

It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting. — Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Where reference is made to a numerical — value using a term such as, for example, about or substantially, the exact numerical value is also disclosed. > As used herein, a plurality of items, structural elements, compositional elements, and/or > materials may be presented in a common list for convenience. However, these lists should be ro construed as though each member of the list is individually identified as a separate and unique 2 25 member. Thus, no individual member of such list should be construed as a de facto equivalent of

I any other member of the same list solely based on their presentation in a common group without = indications to the contrary. In addition, various embodiments and example of the present e invention may be referred to herein along with alternatives for the various components thereof. It 2 is understood that such embodiments, examples, and alternatives are not to be construed as de

N 30 facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the description, numerous specific details are provided, such as examples of frames, slots, fasteners, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention.

Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated.

Furthermore, it is to be understood that the use of "a" or "an", that is, a singular form, throughout this document does not exclude a plurality.

INDUSTRIAL APPLICABILITY

Atleast some embodiments of the present invention find industrial application in the field of filters. oO

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Claims

1. A filter assembly (16), comprising: — a frame (6) having a top and a bottom side (7a, 7d) and inner and outer edges (7c, 7b), said inner edges (7c) of said frame defining an aperture, and — abag-like insert (11) of a filter material having an open upper portion (14) and at least one closed bottom portion, characterized by: — a first tape (9) of a fastener attached to the outer edge of said frame and running around the outer edge (7b) of the frame, and by — a second tape (13) of a fastener attached to said upper portion (14) of said insert (11), wherein said first tape (9) is a first half of a zip fastener and said second tape (13) is a second half of a zip fastener said insert is arranged to fit into the aperture of said frame (6) with said open upper portion (14) bent over said frame to completely cover the top side of the frame and to mate said first and second zip fastener halves (9, 13) with each other to form a sealable zip fastener when pulling a slider (10) provided in either one of said first or second zip fastener halves, to form a sealed joint at said outer edge (7b) of the frame (6) when said first and second halves of said zip fastener are fully engaged with each other.

2. A filter assembly according to claim 1, characterized by that said frame (6) is provided with parallel intermediate bars (8) across said aperture defining slots (A, B, C) across said aperture, _ 20 and wherein said insert (11) has multiple bags (12) formed in a pleated fashion having a shared O open upper portion (14) and separate closed bottom portions, and wherein each bag (12) is O arranged to fit into one slot (A, B, €). x

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3. A filter assembly according to claim 1, characterized by that said frame (6) is provided with a I = grid of intermediate bars (22, 23) across said aperture defining a number of slots (25), and © 25 wherein said insert (11) is formed as multiple bags having a shared open upper portion (14) and 0 S separate closed bottom portions, and wherein each bag is arranged to fit into one slot (25). O

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4. A filter assembly according to any of claims 1 - 3, characterized by that the mating of said first and second zip fastener halves (9, 13) with each other to form a sealable zip fastener is effected by an insert pin (15) on either one of the first and second zip fastener halves that is inserted to a slider in the opposite zip fastener half.

5. A filter assembly according to any of claims 1 - 4, characterized by that said frame (6) has the shape of a rectangle or a square.

6 A filter assembly according to any of claims 1 - 5, characterized by that said frame (6) is made of a rigid material selected any one of the following: wood, metal or a polymer material.

7. A filter assembly according to any of claims 2 - 6, characterized by that said intermediate bars (8; 22, 23) across said aperture are bars attached to the frame (6) by any means of fastening.

8. A filter assembly according to any of claims 2 - 6, characterized by that said intermediate bars (8; 22, 23) across said aperture are integral with and formed of the same material as said frame (6) in one manufacturing process. N O N O + I a a © 0 LO O O N