Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
  • B01D46/52—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material
  • B01D46/521—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
  • F24F8/10—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering
  • F24F8/108—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering using dry filter elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
  • B01D46/0002—Casings; Housings; Frame constructions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
  • B01D46/10—Particle separators, e.g. dust precipitators, using filter plates, sheets or pads having plane surfaces
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
  • F24F8/00—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying
  • F24F8/10—Treatment, e.g. purification, of air supplied to human living or working spaces otherwise than by heating, cooling, humidifying or drying by separation, e.g. by filtering
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D2265/00—Casings, housings or mounting for filters specially adapted for separating dispersed particles from gases or vapours
  • B01D2265/06—Details of supporting structures for filtering material, e.g. cores

Definitions

• the present invention relates to a frame for an air filter unit comprising a filter package and possibly at least one grid, said frame being built up of elongate elements having flanges along the long sides thereof and an air filter unit comprising such a frame.
• Air filter units are comprised of metal frames, preferably of aluminium, in which a filter package of fibrous material and possibly at least one grid, possibly of steel, are mounted.
• the frame functions partly to hold the components together, partly to protect the filter package from external loads, which could be detrimental to the efficiency of the filter package.
• the frame must be leak-proof so that all air passes through the filter package. For these reasons, the frame must be rather rigid in order to ensure that the risk for leakage in the manufactured air filter unit is minimised.
• the filter package gets more and more contaminated and finally the air filter unit must be substituted by a fresh one.
• the used air filter unit must be disposed of, preferably by incineration of the filter package. Before incineration, the filter package must be removed from the frame and possibly also from the grid or grids.
• the disposal of used air filter units creates problems in several aspects. Firstly, the used air filter units must be stored before transportation to an incineration plant or the like which requires a lot of space. The space requirement can be reduced if the filter packages and the possible grids are dismounted from the frame, the components take less space if stored separately than in assembled condition. Furthermore, the space required by separate filter packages, can be reduced by compacting. It would therefore be advantageous to separate the components of the used air filter units before transportation to an incineration plant or the like.
• the objective of the present invention is to facilitate a reduction of the space taken by stored, used air filter units, facilitate the disposal of used air filter units and reduce the weight of the frame of an air filter unit, while still maintaining the risk for leakage from the frame at minimum.
• a frame for an air filter unit comprising a filter package and possibly at least one grid, said frame being built up of elongate elements having flanges along the long sides thereof, characterised in that the frame is made of elements of plastic material, each element has a central stiffening rib on the side thereof facing said filter package in an assembled air filter unit.
• Such a frame can be incinerated together with the filter package and the possible grid (then being made of incinerable material), thereby making the step of dismounting the components of a used filter air unit unnecessary.
• a compacting of a used air filter unit is also possible without requiring a dismounting of the components.
• said rib extends over 30-70% of the width of said frame element, is hollow and comprises a central string of material dividing the internal space of the rib into two similar spaces.
• the height of the rib is preferably twice the thickness of elongate elements of the frame.
• the frame can be made of ABS-plastic.
• the invention also relates to an air filter unit comprising a frame of the aforesaid type, a filter package and at least one grid mounted in said frame, characterised in that said grid is made of plastic material, preferably polycarbonate.
• a grid can be disposed on both sides of the filter package.
• Fig. 1 shows a partial cross-sectional view of an air filter unit comprising a frame according to a preferred embodiment of the present invention
• Fig. 2 shows a perspective view of a part of a frame element according to a preferred embodiment of the present invention.
• the air filter unit according to figure 1 comprises a filter package 1 , an upper and lower grid 2 and 3, respectively, and a frame 4 holding the components 1- 3 together.
• the air filter unit is rectangular and the frame 4 comprises four elongate elements 5 being held together with the aid of corner clips.
• Other means than clips can also be used for holding the frame parts together.
• the individual parts can be joined together by a chemical seal with an adhesive or by adding a tape, by designing the end parts in such a way that they can be mechanically locked together, by mechanical fasteners such as screws, staples or rivets, or by fusing the parts together with known methods of heat sealing, friction welding, radio frequency welding, high frequency welding, ultra sonic welding, etc.
• the filter package 1 is of a type in which the air passing through the filter package leaves the package in an even flow directed perpendicular to the plane of the frame 4.
• the filter package can for example be of the type described in US 5,236,480.
• Such a filter package comprises a first sheet of filter material, for example a fibre glass material, folded in a zig-zag configuration to form alternating open portions and apex portions at air inlet and outlet sides of said folded sheet material.
• the apex portions at the air outlet side of the folded first sheet lie substantially in a common plane.
• a second sheet of air permeable fine mesh material is extended over the apex portions of the first sheet on the air outlet side of the filter package.
• the grids 2 and 3 is comprised of a great number of small plastic tubes being affixed to each other in some suitable manner, for example glued to each other.
• the tubes has a diameter of 3-10 mm, preferably 5-6 mm, more preferably 3 mm, and a length of 5-60 mm, preferably 7.5 mm.
• the grids are advantageously made of polycarbonate.
• each elongate element 5 is provided with a central rib 9 extending along the length of said element and having a width being 30-70% of the total width of said element 5.
• Said rib 9 is hollow and its internal space is divided into two similar spaces 10 and 11, respectively by a central string of material or an internal wall 12.
• the rib 9 has a cross-section in the shape of a trapezium.
• the height of the rib 9, i.e. the distance it is raised above the inner surface of the rib 9, is twice the thickness of the main part 6 of the elongate element 5 and the height of the internal spaces 10 and 11 corresponds to the thickness of the main part 6 of the elongate element 5. It has been found that the rigidity of an elongate element 5 provided with a rib 9 covering 52% of the width of said element is increased with 78% in comparison with a similar element without a rib.
• the flanges 7,8 projecting inwards perpendicular to the main part 6 of the frame element 5 have, on their opposite inner sides, grooves 13,14 constructed to hold corner clips (not shown) when the air filter unit is assembled.
• the upper flange 7 is also provided with a groove 15 for holding a gasket 16 of resilient material, for example expanded polyurethane.
• the filter package 1 is affixed to the ribs 9 on the frame elements 5 by a sealant 17, for example polyurethane adhesive.
• a sealant 17 for example polyurethane adhesive.
• This sealant does also fill up the empty spaces between the flanges 7,8.
• the grid 3 is glued to the frame element 5 and to the filter package 1 by a polyurethane adhesive and the grid 2 is glued to the filter package 1 by a hot melt adhesive.
• the grids 2,3 can be manufactured by gluing a bundle of long tubes together and then cut planar grid pieces from the bundle of joined tubes.
• the tubes have a circular cross-section.
• the tubes can have any cross-sectional shape.
• the tubes can have a hexagonal cross-section.
• the air filter unit may only contain one grid on its outlet side, i.e. the side turned downwards in figure 1.
• the rib can have other dimensions and other trapezium shapes than the shape shown in figures 1 and 2. It is not absolutely necessary to provide the air filter unit with a grid, although this is preferred in order to fully protect the filter package.
• Other plastic materials than the ones mentioned could be used for manufacturing of the frame and grid, for example polypropylene, polycarbonate, polystyrene, polyethylene, polyamides, etc. The scope of invention shall therefore only be determined by the wording of the enclosed patent claims.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=32768762

Family Applications (1)

Country Status (2)

Cited By (3)

Citations (7)

• 2004
  • 2004-07-05 SE SE0401747A patent/SE0401747D0/sv unknown
• 2005
  • 2005-07-04 WO PCT/SE2005/001104 patent/WO2006004540A1/en active Application Filing

Patent Citations (7)

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