Air filter assembly

Abstract

Provided is an annular filter assembly comprising a filter body and at least one gasket. The filter body comprises an inner tube having multiple apertures, the inner tube defining an inner wall of the body and an airflow path, and an outer tube having multiple apertures, the outer tube surrounding the inner tube and defining an outer wall of the body. A filter medium is disposed between the inner tube and the outer tube. A first end cap and a second end cap are configured to be releasably fastened to the inner tube and the outer tube. The first end cap is arranged on an axial end of the inner tube and the outer tube and is configured with an opening in communication with the airflow path of the inner tube. The second end cap is arranged on an opposing axial end of the inner tube and the outer tube. The at least one gasket is configured to be releasably fastened to the first end cap or the second end cap, wherein the gasket is configured with at least one vibration isolator adapted to be in contact with the first end cap or the second end cap. The at least one vibration isolator is configured to substantially dissipate vibrations from being transferred to the filter body.

Description

AIR FILTER ASSEMBLYTechnical Field

[0001] This disclosure generally relates to air filter assemblies. In particular, this disclosure concerns an air filter having a housing for reducing vibrations created from external sources.Background

[0002] Air treatment systems are essential equipment at hazardous worksites. They are used to maintain air quality, enhance the performance of machinery and equipment, and ensure personnel safety. These systems use air filters to remove hazardous particulates and noxious gases from the air. The treated air is subsequently circulated into the local environment, designated enclosed spaces, or personnel-occupied spaces.

[0003] The air filters installed in the housing of the air treatment system are susceptible to prolonged exposure to vibration forces created by the air treatment system or from forces external to the housing. This leads to the accumulation of damage that leads to increased failure rates and the rapid wearing of the air filters. This results in the rapid degradation of the overall efficiency of the air treatment system and increases the frequency of maintenance to replace the air filter.

[0004] The air filters are typically manufactured as a single unit and considered a commodity for periodic replacement. The air filters are manufactured according to a standard template, leading to a commodity that cannot be easily modified or repaired by end users. This results in increased costs for organisations that must purchase bulk quantities of various models to ensure a sufficient supply for regular maintenance events and to cater to all operational requirements. Additionally, the requirement for bulk quantities leads to increased storage space requirements and discourages the consideration of sustainability in the operational practice of organisations.

[0005] Any discussion of documents, acts, materials, devices, articles or the like which have been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

[0006] Throughout the specification unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0007] Throughout the specification unless the context requires otherwise, the word "include" or variations such as "includes" or "including", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.Summary of Invention

[0008] According to a first aspect, there is provided an annular filter assembly, comprising: a filter body, comprising: an inner tube having multiple apertures, the inner tube defining an inner wall of the body an airflow path; an outer tube having multiple apertures, the outer tube surrounding the inner tube and defining an outer wall of the body; a filter medium disposed between the inner tube and the outer tube; and a first end cap and a second end cap configured to be releasably fastened to the inner tube and outer tube, the first end cap is arranged on an axial end of the inner tube and the outer tube, and the second end cap is arranged on an opposing axial end of the inner tube and the outer tube, and wherein the first end cap is configured with an opening in communication with the airflow path of the inner tube; and at least one gasket configured to be releasably fastened to the first end cap or the second end cap;wherein the gasket is configured with at least one vibration isolator adapted to be in contact with the first end cap or second end cap; and wherein the at least one vibration isolator is configured to substantially dissipate vibrations from being transferred to the filter body.

[0009] In an embodiment, the at least one vibration isolator is at least one projecting strip configured to resiliently deform when the gasket is fastened to the first end cap or the second end cap, and revert to its original position when unfastened from the first end cap or the second end cap.

[0010] In an embodiment, the projecting strip is made from a polymer material, a metal, or a metal alloy.

[0011] In an embodiment, the at least one vibration isolator is a plurality of springs.

[0012] In an embodiment, the at least one vibration isolator is a plurality of elastomer mounts.

[0013] In an embodiment, the axial end and the opposing axial end of the inner tube and the outer tube are configured with a plurality of protruding tabs; and wherein the first end cap and the second end cap are configured with a plurality of slots or tabs configured to releasably receive the plurality of protruding tabs

[0014] In an embodiment, the inner tube and the outer tube are each configured as a rigid mesh tube.

[0015] In an embodiment, the second end cap is configured with an opening in communication with the airflow path in the inner tube.

[0016] In an embodiment, the second end cap is configured as a seal.

[0017] In an embodiment, the opening of the first end cap is configured with a filter and the second end cap is configured with a deflector projecting into the airflow path.

[0018] In an embodiment, the inner tube and the outer tube are tapered to form a conical filter body.

[0019] In an embodiment, the filter medium is made from fibreglass, cotton, metal, paper, polymer material, or reinforced polymer.

[0020] In an embodiment, the filter medium is pleated.

[0021] In an embodiment, the filter medium is made from polymer foam.

[0022] In an embodiment, the inner tube, the outer tube, the first end cap, and the second end cap are manufactured by injection moulding.Brief Description of Drawings

[0023] In order to provide a better understanding, embodiments of the present invention will be described, by way of example only, with reference to the accompanying drawings, in which:FIG. 1 is a section view of one embodiment of a filter assembly installed in an air treatment system.FIG. 2 is an exploded view of the filter assembly.FIG. 3 is a perspective view of a filter body of the filter assembly.FIG. 4 is a section view of the filter body before fastening to a gasket.FIG. 5 is a section view of the filter body after fastening to the gasket.Description of Embodiments

[0024] The preferred embodiments of the present disclosure will be described with reference to the drawings. The present disclosure illustrates a device having several identical elements, such as vibration isolators and fastening elements. In this respect, it will be appreciated that identical elements in the figures are identified with the same reference numbers.

[0025] The present disclosure is related to an annular filter assembly for use in an air treatment system located in a hazardous environment or for high throughput applications. In particular, the air treatment system may be mounted to a moving vehicle or may be operated for a prolonged period. The annular filter assembly may be installed in air treatment systems at other locations and for other uses and is not intended to be limited to the examples and embodiments described below.

[0026] FIGS. 1 and 2 illustrate a preferred embodiment of the annular filter assembly 10 used in the air treatment system 12. The annular filter assembly 10 is comprised of a filter body 14 and a pair of gaskets 16, 18. The filter body 14 is further configured to receive airflow in the air treatment system 12 and to substantially remove particulate matter using a combination of filtration mechanisms including diffusion, interception, and impaction. The pair of gaskets 16, 18 are configured to be releasably fastened to the filter body 14 at an axial end and an opposing axial end. Additionally, the pair of gaskets 16, 18 are further configured to be releasably fastened to the air treatment system 12 housing.

[0027] The filter body 14 is configured to be assembled and disassembled without tools. This enables the individual components of the filter body 14 to be maintained or replaced without necessitating the discarding of the entire filter body 14. This advantageously allows for the increased ease of the production process, and the reduced cost of manufacture by removing the use of tools, adhesives, or fasteners from the production process. Additionally, the individual components may be tailored to meet the specific operational requirements of different air filter systems and still be compatible with the other components. The modularity of the filter body 14 enables manufacturing on demand with reduced costs in production and enables rapid adaptation of the filter body 14 in the field of operation.

[0028] The pair of gaskets 16, 18 are configured with at least one vibration isolator projecting from a face that contacts the first end cap 26 or the second end cap 28. This advantageously allows the pair of gaskets 16, 18 to substantially isolate the filter body 14 from the vibrations generated external to the annular filter assembly 10 from the air treatment system 12. The reduction in the transfer of vibrations to the filter body 14 leads to prolonged operational life of the filter body 14 by reducing the need for maintenance or replacement of the filter body 14 or its individual components. Additionally, the pair of gaskets 16, 18 is configured to be releasably fastened to each axial end of the filter body 14 and releasably fastenedto the air treatment system 12 advantageously allowing for the ease of replacement of the gaskets 16, 18 without the use of tools, adhesives, or fasteners, and promotes a sustainable approach to spare parts management.

[0029] The filter body 14 is configured to be assembled and disassembled by a worker without using tools preferably in a controlled facility to ensure adherence to international safety protocols. The filter body 14 may also be assembled and disassembled in the field of operation by the worker without using tools. This enables the modification of the filter body 14 to suit operational requirements and enables on-field maintenance or replacement.

[0030] FIGS. 2 and 3 illustrate the filter body 14 being comprised of an inner tube 20 and an outer tube 22. The inner tube 20 and the outer tube 22 has multiple apertures on their bodies to enable airflow to pass through them. The inner tube 20 defines an inner wall of the filter body 14 and an interior for an airflow path. The outer tube 22 surrounds the inner tube 20 to define an outer wall of the filter body 14. A filter medium 24 is disposed between the inner tube 20 and the outer tube 22. The filter medium 24 is configured to filter airborne particulates that pass through the multiple apertures of the inner tube 20 and the outer tube 22.

[0031] In a preferred embodiment, the filter medium 24 is a pleated cotton, paper, polymer material, or reinforced polymer to provide a higher surface area and increase the filtration efficiency for general-purpose applications. In other embodiments, the filter medium 24 may be non-pleated and manufactured from materials such as metal, fibreglass or polymer foam. It would be appreciated by a person skilled in the art that the filter medium 24 material would be selected based upon the operational requirements and what particulates and / or other undesirable matter, including bacteria, dust, pollen, and mould, are to be removed.

[0032] A pair of end caps, consisting of a first end cap 26 and a second end cap 28, is configured to be releasably fastened to the inner tube 20 and the outer tube 22 at an axial end and an opposing axial end. The pair of end caps 26, 28, when fastened to the inner tube 20 and the outer tube 22, provide structural support to the filter body 14, creating a substantially rigid filter body 14 and a protective shell for the filter medium 24. In an embodiment, the pair of end caps 26, 28, when fastened to the inner tube 20 and the outer tube 22, causes the inner tube 20 and the outer tube 22 to apply compression to the filter medium 24. This sandwichesthe filter medium 24 between the inner tube 20 and the outer tube 22, to substantially arrest the moment of the filter medium 24. The combination of the substantially rigid filter body 14 and the sandwiched filter medium 24 reduces the risk of the filter body 14 from any negative effects, such as damage or deformation, created by external shock or vibrations.

[0033] In a preferred embodiment, as shown in FIGS. 1 to 3, the filter body 14 is configured to have an unobstructed airflow path that travels from an axial end of the inner tube 20 to the opposing axial end. In this embodiment, the first end cap 26 and the second end cap 28 are each configured with an opening in communication with the airflow path of the inner tube 20.

[0034] In alternative embodiments, the filter body 14 may be configured to either direct airflow external to the filter body 14 through the outer tube 22 and inner tube 20 to the interior to the airflow path or vice versa.

[0035] In an embodiment, the filter body 14 may be configured with the first end cap 26 configured with an opening in communication with the airflow path of the inner tube 20 at an axial end, and the second end cap configured as a seal blocking the airflow path of the inner tube 20 at the opposing axial end. It would be appreciated that in this embodiment, the first end cap 26 acts as an outlet for the airflow path, and the second end cap 28 acts as a seal. This arrangement encourages the air external to the filter body 14 to be drawn through the outer tube 22 and the filter medium 24 thereby filtering particulates from the air. The filtered air is then drawn through the inner tube 20 and enters the airflow path before it is drawn through the opening of the first end cap 26.

[0036] In another embodiment, the filter body 14 may be configured with the first end cap 26 having an opening with a filter in communication with the airflow path of the inner tube 20 at an axial end. The second end cap is configured with a deflector that projects into the airflow path and seals the airflow path of the inner tube 20 at the opposing axial end. It would be appreciated that in this embodiment, the first end cap 26 acts as an inlet for the airflow path and the second end cap 28 deflects the air entering from the first end cap 26 through the inner tube 20 and through the filter medium 24 thereby filtering particulates from the air. The filteredair is pushed through the outer tube 22, wherein it enters the space external to the filter body 14.

[0037] The inner tube 20 and the outer tube 22 are configured with a plurality of projections or tabs at the axial end and the opposing axial end of the tubes 20, 22. The plurality of projections or tabs are adapted to be releasably received by corresponding projections, tabs, or slots located on the first end cap 26 and the second end cap 28.

[0038] FIG. 2 illustrates a preferred embodiment, wherein the fastening means comprise L-shaped tabs 30 projecting from the axial ends of the inner tube 20 and the outer tube 22, that upon rotation, mate with corresponding tabs 32 located at the first end cap 26 and the second end cap 28. It would be appreciated by the person skilled in the art that the other releasable fastening mechanisms may be used, such as bayonet and snap-fit fastening mechanisms.

[0039] In a preferred embodiment, as demonstrated in FIGS. 1, 2, 3, and 5, the inner tube 20 and the outer tube 22 are configured as rigid mesh tubes, having a plurality of apertures that are equally spaced and dimensioned. The inner tube 20 and outer tube 22, when configured as rigid mesh tubes, enable more surface area of the filter medium 24 to be exposed to the airflow generated from within the airflow path of the inner tube 20 or external to the filter body 14. It would be appreciated by the person skilled in the art that the inner tube 20 and the outer tube 22 could be configured with a plurality of perforations or differently shaped and spaced apertures throughout the length of the tubes 20, 22. This allows the inner tube 20 and / or the outer tube 22 to influence the fluid dynamics of the airflow and / or act as a sieve to separate unwanted particulates.

[0040] In a preferred embodiment, the inner tube 20 and the outer tube 22 are tapered to create a conical filter body 14. This causes the axial end and the opposing axial end to have different diameters, increasing the surface area of the filter medium 24 when receiving airflow.

[0041] In a preferred embodiment, the inner tube 20, the outer tube 22, the first end cap 26 and the second end cap 28 are made from polymer material and are manufactured by injection moulding. In another embodiment, the tubes 20, 22 and the end caps 26, 28 are made from metal or composite materials. In a furtherembodiment, the tubes 20, 22 and the end caps 26, 28 are manufactured using 3D printing, casting, compression moulding, or thermoforming techniques.

[0042] The pair of gaskets 16, 18 are configured to be releasably fastened to the first end cap 26 and the second end cap 28 of the filter body and releasably fastened to the housing of the air treatment system 12. The gaskets 16, 18 are further configured with at least one vibration isolator to substantially dissipate vibrations from being transferred from the air treatment system 12 to the filter body 14 and to form a pressure-tight seal between the air treatment system 12 and the filter body 14 to substantially prevent leakage of air flow at this point of contact.

[0043] The at least one vibration isolator is configured as a spring system or an elastomer mount. It is preferable for the at least one vibration isolator to be a spring system as they are unlikely to wear out and require replacement unless overloaded. Additionally, the at least one vibration isolator is configured to support the filter body 14 and isolate it from rigid contact with the housing of the air treatment system 12. This ensures that all vibrations and / or shocks will be intercepted and damped by the gaskets 16, 18.

[0044] In a preferred embodiment, as shown in FIGS. 4 and 5, the pair of gaskets 16, 18 are configured with vibration isolators in the form of projecting strips 34 that form a semi-circular or parabolic arch on the face of the gaskets 16, 18 when in contact with and compressed against the end caps 26, 28. The projecting strips 34 are configured to resiliently deform when the gaskets 16, 18 are fastened to the end caps 26, 28. The projecting strips 34 resiliently deform after making contact with annular channels 38 on the surface of the end caps 26, 28. The annular channels 38 are rounded to guide the projecting strips 34 to resiliently deform whilst minimising the likelihood of breakage. The projecting strips 34, when resiliently deformed and under compression, act as spring systems for damping vibrations and subsequently prevent the transfer of vibrations from the air treatment system to the filter body 14. Additionally, the resiliently deformable projecting strips 34 allows for the cushioning of forces generated from pressure differences between the environmental external to and internal to the filter body 14. Upon the gasket 16, 18 being unfastened from the end caps 26, 28, the projecting strips 34 will revert to their original extended positions. In this preferredembodiment, the projecting strips 34 are projected at an angle to assist with resilient deformation after contact with the annular channels 38. Additionally, the projecting strips 34 extend in a generally axial direction of the filter body 14 and are angled towards the outer circumference of the gaskets 16, 18, so that any external forces acting on the air filter assembly 10 would be pushing against the angle of projecting strips 34. Vibration isolators in the form of projecting strips 34 that extend in this way are particularly effective in dissipating vibrations. The projecting strips 34 substantially resist deformation from the external forces, thereby reducing the risk of leakage created by the project strips 34 compressing further and creating a gap between the filter body 14 and the housing of the air treatment system 12. It would be appreciated by the person skilled in the art that the projection angle may be of any value to cater to the physical properties of the material used to manufacture the projecting strips 34, the designed height tolerance of the gaskets 16, 18, and any other engineering considerations.

[0045] In an embodiment, the pair of gaskets 16, 18 may be configured with vibration isolators in the form of a plurality of springs that project from the surface of the gaskets 16, 18. These springs are preferably spaced accordingly to enable sufficient and balanced damping of vibration. It would be appreciated that the use of the plurality of springs may provide improved damping capability but increase the cost of maintenance or replacement of the gaskets 16, 18 in comparison to the use of projecting strips 34.

[0046] In another embodiment, the pair of gaskets 16, 18 may be configured with vibration isolators in the form of one or more elastomer mounts, such as rubber pads or rubber nubs, that are mounted on the surface of the gaskets 16, 18. It would be appreciated that using the one or more elastomer mounts may provide sufficient damping capability but are likely to require replacement at a faster rate due to frictional wear.

[0047] In a preferred embodiment, the gaskets 16, 18 are configured with an outer projection 36 located on the outer circumference of the gaskets 16, 18. The outer projection 36 is configured to act as an energy dissipating barrier to prevent the end caps 26, 28 from contacting the housing of the air treatment system 12 and to reduce the effects of impacts if large lateral movements are generated during use. In this preferred embodiment, the outer projection 36 is configured as a fluted wallthat does not support the end caps 26, 28. However, it would be appreciated that the outer projection 36 may abut the end caps 26, 28 to support the end caps 26, 28 alongside the projecting strips 34 and may have any shape that assists with dissipating impact energy.

[0048] In an embodiment, the gaskets 16, 18 are made from metal, polymer material, or composite materials. In another embodiment, the projecting strips 34 and the outer projection 36 are made from a different material to the main body of the gaskets 16, 18. In this embodiment, the project strips 34 and the outer projection 36 are made from polymer material, metal, or metal alloy. In a further embodiment, gaskets 16, 18 have a projecting wall located at the outer circumference of the gaskets 16, 18.

[0049] In a preferred embodiment, as shown in FIGS. 4 and 5, the gaskets 16, 18 are configured with tabs 40 that mate with a corresponding snap-in area of the housing of the air treatment system 12. It would be appreciated by the person skilled in the art that other releasable fastening mechanisms may be used, such as bayonet and snap-fit fastening mechanisms.

[0050] It will be appreciated by persons skilled in the art that numerous variations and / or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims

Claims1. An annular filter assembly, comprising: a filter body, comprising: an inner tube having multiple apertures, the inner tube defining an inner wall of the body and an airflow path; an outer tube having multiple apertures, the outer tube surrounding the inner tube and defining an outer wall of the body; a filter medium disposed between the inner tube and the outer tube; and a first end cap and a second end cap configured to be releasably fastened to the inner tube and outer tube, the first end cap is arranged on an axial end of the inner tube and the outer tube, and the second end cap is arranged on an opposing axial end of the inner tube and the outer tube, and wherein the first end cap is configured with an opening in communication with the airflow path of the inner tube; and at least one gasket configured to be releasably fastened to the first end cap or the second end cap; wherein the gasket is configured with at least one vibration isolator adapted to be in contact with the first end cap or second end cap; and wherein the at least one vibration isolator is configured to substantially dissipate vibrations from being transferred to the filter body.

2. An air filter assembly according to claim 1, wherein the at least one vibration isolator is at least one projecting strip configured to resiliently deform when the gasket is fastened to the first end cap or the second end cap.

3. An air filter according to claim 2, wherein the projecting strip extends generally axially of the filter body.

4. An air filter assembly according to claim 1, wherein the at least one vibration isolator is a plurality of springs.

5. An air filter assembly according to claim 1, wherein the at least one vibration isolator is a plurality of elastomer mounts.

6. An air filter assembly according to any one of the preceding claims, wherein the axial end and the opposing axial end of the inner tube and the outer tube are configured with a plurality of protruding tabs; and wherein the first end cap and the second end cap are configured with a plurality of slots or tabs configured to releasably receive the plurality of protruding tabs.

7. An air filter assembly according to any one of the preceding claims, wherein the inner tube and the outer tube are each configured as a rigid mesh tube.

8. An air filter assembly according to any one of the preceding claims, wherein the second end cap is configured with an opening in communication with the airflow path of the inner tube.

9. An air filter assembly according to any one of claims 1 to 7, wherein the second end cap is configured as a seal.

10. An air filter assembly according to any one of claims 1 to 7, wherein the opening of the first end cap is configured with a filter and the second end cap is configured with a deflector projecting into the airflow path.

11. An air filter assembly according to any one of the preceding claims, wherein the inner tube and the outer tube are tapered to form a conical filter body.

12. An air filter assembly according to any one of the preceding claims, wherein the filter medium is formed from fibreglass, cotton, metal, paper, polymer material, or reinforced polymer.

13. An air filter assembly according to claim 12, wherein the filter medium is pleated.

14. An air filter assembly according to any one of claims 1 to 11, wherein the filter medium is made from polymer foam.

15. An air filter assembly according to any one of the preceding claims, wherein the inner tube, the outer tube, the first end cap, and the second end cap are manufactured by injection moulding.

Images