FR2672511A1 - FILTER CARTRIDGE. - Google Patents

Abstract

The filter cartridge 16 comprises two cylindrical filtering surfaces 22 and 24 coaxial made from a membrane covered with a layer of expanded polytetrafluoroethylene (PTFE). The filtering surfaces 22 and 24 are secured to their base 27 and 29 by a radial wall 36 and the central filtering surface 24 is closed by a disc 38. A tie rod 40 urges a ring 26 integral with the peripheral filtering surface 22 in sealed bearing on the wall 30 of a suction device. The peripheral filter cartridge 22 is lined with a retaining grid 44. The filter cartridge 16 can be used in a domestic and / or industrial vacuum cleaner.

Description

FILTER CARTRIDGE

  The present invention relates to filter cartridges that can be used in particular in domestic air cleaners

or industrial.

  In the field of filtration, it is often interesting to increase the filtration area of a filter in particular to reduce the pressure losses at the latter is known in particular filter cartridges with cylindrical filter surface constituted However, this solution is not applicable to all types of paper or filter fabrics, some of them being susceptible

  tearing at the folds.

  The invention relates to a new type of filter cartridge with a large filter surface. According to the invention, the filter cartridge of the cylindrical filter surface type comprises a plurality of filtering surfaces arranged coaxially to define at least one surface

  Peripheral filter and a central filter surface.

  Thus, thanks to the invention, it is possible to use filtering materials (fabrics, felts, membranes) having improved filtration characteristics, particularly with respect to clogging resistance, but which

  otherwise do not resist or resist folding.

  Advantageously, according to one embodiment of the invention, the cylindrical filtering surfaces are made from a membrane having a microporous layer, preferably expanded polytetrafluoroethylene, said layer

  being arranged on the inlet side of the filter.

  According to another embodiment of the invention, the filtering cartridge comprises a sealing abutment ring integral with one end of the peripheral filtering surface to define therein an axial opening for discharging the fluid after filtration, a disc forming partition mounted at one end of the central filtering surface, each filtering surface being further secured to the adjacent filtering surface by a radial connecting plate attached to one of its ends, said ring, the radial plate (s) (s) ) and the disk thus defining cartridge partition elements mounted alternately at the ends of the filtering surfaces, each end of the filtering surfaces cooperating with a single partitioning element Advantageously, the filtering cartridge comprises holding grids for the filtering surfaces arranged between the two partitioning elements associated with the filtering surface c It is preferred to use the fluid evacuation side after filtration. This simple structure arrangement is interesting from the point of view of cost.

Manufacturing.

  According to a variant of the embodiment of the preceding invention, the cartridge is intended to be mounted in a fluid conduit via fastening means acting on the disk to urge the stop ring.

  in sealed support on the wall of said pipe.

  Advantageously, the support grids are provided only

  for filtering surfaces working in compression.

  This arrangement makes it possible to simplify the structure of the filter cartridge and to improve the resistance to clogging (by eliminating the support grid for

  filtering surfaces working in tension).

  Other features and benefits of this

  invention will appear on reading the description which will

  follow with reference to the accompanying drawings in which: Figure 1 is a schematic sectional view of a bucket type vacuum cleaner in which is mounted a

  filter cartridge according to the invention.

  FIG. 2 represents a schematic perspective view

  of a filter cartridge according to the invention.

  FIG. 3 represents a schematic view in axial section

  of the filter cartridge of Figure 2.

  and FIG. 4 is a diagrammatic view in axial section of another model of filter cartridge according to the invention. The vacuum cleaner type "bucket" illustrated in Figure 1 comprises a cylindrical body 10 provided with a chamber 11 dust receptacle 12 supplied with air to be filtered from a pipe 14 The air is filtered through a filter cartridge according to the invention 16 by suction with the aid of a turbine 18 driven by an electric motor 20 The conventional air circulation for a bucket-type vacuum cleaner is illustrated by an arrow path shown in FIG. A first embodiment of a filter cartridge according to the invention is illustrated schematically in perspective in FIG. 2 and in section in FIG. 3. The cartridge 16 comprises a plurality of cylindrical filtering surfaces (in this case two) disposed coaxially. relative to the axis XX 'for defining a peripheral filter surface 22 and a central filtering surface 24 The peripheral filtering surface 22 carries at one of its ends 25, a ring 26 of sealing abutment it can come into sealing engagement via a seal 28 on the wall 30 of the inlet duct 32 of the turbine of the vacuum cleaner, said ring 26 thus defining an axial opening 34 for discharging the fluid after filtration The other end 27 of the peripheral filter surface 22 carries a radial connecting plate with the adjacent end 29 of the adjacent filtering surface (in this case the central filtering surface 24) Finally the free end 31 of the filtering surface 24 is closed by a partition disc 38 As illustrated in FIG. 3, the ring 26, the disc 38 and the radial plate 36 define partition elements of the cartridge mounted alternately at the ends of the filtering surfaces, each end In addition, the central filtering surface 24 has a reduced axial length with respect to the filtering surface by cooing only with a single partitioning element. peripheral filtration surface 22 to clear a free passage of filtered air towards the opening 34 The filtering surfaces are made from a membrane such as for example a fabric or felt covered with a microporous layer of Expanded polytetrafluoroethylene (PTFE), the layer being placed on the inlet side of the filter (chamber 11) to prevent internal clogging In an embodiment described here, the filtering surfaces 22 and 24 consist of a filter membrane marketed under the GORE-TEX trademark. by the company "WL GORE & ASSOCIES" well suited to the field of

  filtration especially for dusting.

  The cartridge is pressed against the wall 30 by means of a tie rod 40 secured to the frame of the vacuum cleaner. The free end of the tie rod 40 projects through the disc 38 to receive a mounting nut 42 as illustrated. In FIG. 3 it may be noted that the mounting arrangement of the filter cartridge on the wall 30 is such that the central filtering surface (or membrane) 24 is subjected to axial tensile forces (to which the membrane 24 resists without the particular holding device) while the peripheral filter surface 22 is subjected to axial compressive forces, which requires for the latter only

  the presence of a perforated support grid 44.

  It should be noted the great simplicity of construction of the filter cartridge according to the invention, the disk, radial plate and ring being made of metal or plastic materials (PVC) secured to the filtering surfaces by heat sealing. FIG. 4 illustrates another embodiment of a filter cartridge according to the invention in which three cylindrical filtering surfaces coaxial with respect to the axis Y, Y 'have been provided. This cartridge which is of very similar construction to that of the cartridge illustrated in the figures

  2 and 3 will not be described again in detail.

  The cartridge of FIG. 4 has three cylindrical filtering surfaces H 10, 112 and 114 made of "GORE-TEX" brand membranes presented above. The peripheral surface 110 carries at its ends the bearing ring 116 and the radial plate. 118 The latter filtering surface 112 carries at its other end the radial plate 120 connecting it to the central surface 114 Finally, the central plate 122 is closed at its free end by the disc 122 The cartridge is maintained in sealed support on the wall 124 of the vacuum cleaner by means of the tie rod 126 and the nut 128 acting on the disc 122 It may be noted that the two cylindrical filtering surfaces 110 and 114 stressed-in compression are doubled by grids holding 130

  and 132 as illustrated in Figure 4.

  Of course, the use of the filter cartridges, according to the invention, is not limited to industrial and / or domestic air aspirators and extends to the field of filtration of fluids generally gaseous and / or liquid, in particular filters for internal combustion engines, in particular for motor vehicles and construction machinery

public.

Claims (4)

  Filter cartridge of the cylindrical filter surface type, characterized in that it comprises a plurality of filtering surfaces (22-24, 110-112-114) arranged coaxially to define at least one filtering surface   device (22-110) and a central filter surface (24-   114). Cartridge according to claim 1, characterized in that the filtering surface is made from a membrane having a microporous layer, preferably expanded polytetrafluoroethylene (PTFE), said layer being arranged on the inlet side of the filter.   Cartridge according to one of claims 1 and 2,   characterized in that it comprises a sealing abutment ring (26, 116) integral with one end of the peripheral filter surface (22-110) to define therein an axial opening for discharging the fluid after filtration, a partition disk (38, 122) mounted at one end of the central filtering surface (24, 114), each filtering surface being further secured to the adjacent filtering surface by a fixed connecting plate (36, 118-120) at one of its ends, said ring, the radial plate (s) and the disc thus defining cartridge partition elements alternately mounted at the ends of the filtering surfaces, each end of the filtering surfaces co-operating with a only partitioning element.   4 cartridge according to claim 3, characterized in that it comprises holding grids (44, 130-132) for the filtering surfaces arranged between the two partitioning elements associated with the filtering surface concerned,   preferably on the fluid discharge side.   Cartridge according to one of claims 3 and 4,   characterized in that the cartridge is adapted to be mounted in a fluid conduit (32) via securing means (4042, 126-128) acting on said disk (38-122) to bias said abutment ring ( 26, 116) in sealing engagement with the wall (30, 124) of said conduit.   Cartridge according to claims 4 and 5 taken in   combination, characterized in that the holding grids (44, 130132) are provided only for the surfaces   filters working in compression.