Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L41/00—Branching pipes; Joining pipes to walls
  • F16L41/08—Joining pipes to walls or pipes, the joined pipe axis being perpendicular to the plane of the wall or to the axis of another pipe
  • F16L41/14—Joining pipes to walls or pipes, the joined pipe axis being perpendicular to the plane of the wall or to the axis of another pipe by screwing an intermediate part against the inside or outside of the wall

Definitions

• the present invention relates to a method of fixing a nozzle on a sintered metal filter element and the product thus obtained.
• the metallic filter elements are generally produced by sintering a metallic powder, for example of standard stainless steel.
• 316 according to the AISI nomenclature by adjusting the porosity to obtain the desired filtering effect, while having the lowest possible pressure drop for a given flow rate; they are generally in the form of a cylindrical tube, closed at one end, the other end comprising a nozzle, ensuring the connection with a bearing structure, such as a plate pierced with orifices.
• This set is often called "filter candle".
• the end piece is either welded to the porous tube, or fixed thereto metal lurgically during sintering.
• the first solution has the following drawbacks:
• the weld obtained must be perfectly sound, the presence of cracks generally leading to poor filtration, and in certain cases, to mechanical ruptures, all the more so since this is located near the embedding, that is to say ie in an area where the bending moment (due to vibrations for example) is high.
• a solid metal tip is positioned at one end of the cold compression mold (for example by isostatic pressure) before introduction of the powder into the annular space delimited by a central mandrel and the flexible plastic casing external. After compression, the assembly is sintered, which ensures the metallurgical connection of the nozzle and the tube.
• the nozzle must have dimensions and a shape fairly similar to that of the porous tube
• the method according to the invention makes it possible to avoid the drawbacks mentioned above.
• the method consists of:
• a tubular connecting piece generally externally threaded, provided with a frustoconical end, of the same 1/2 angle at the top as the sintered tube over a height h 'less than h, the small of which diameter (d) is greater than the opening of the tube (t) and whose large diameter (D) is less than the internal diameter of the tube (Ti) - forcibly introduce the tubular connecting piece into the tube so that the average normal stress between the 2 elements above fitted is greater than 2 times the average normal stress imposed by the mounting of the spark plug on its support ( and remains greater than 2 MPa).
• the lateral surface of the truncated cone is provided with one (or more) annular rib (s) having in any cross section any profile, but preferably polygonal (for example triangular) at angles which are printed in the porous tube during press fitting.
• the enlarged end of the sintered tube has an annular housing for a seal (for example, an O-ring).
• the spark plug can also be mounted on its support with an intermediate piece, which is a nut having on its free face, an annular housing for a seal.
• this nut carries on its surface in contact with the enlarged end of the filter tube, one (or more) annular rib (s) analogous to those of the conical end piece, which also prints in the porous tube when it is put in place.
• This nut may have the form of a tubular sleeve provided with two end flanges in the case where it is desired to eliminate a filtering zone at the head of the porous tube, over a certain length.
• - Fi g 2 sectional view of another embodiment according to the invention
• - Fig 3 sectional view (detail) of the frustoconical part with ribs
• a filter element (1) is composed of a porous metallic tube (2) sintered in stainless steel 316 of dimensions 0 56 x $ 60 x 1000 mm having a bottom (3) welded, in stainless steel 316.
• the assembly is mounted on the support (10), using a nut (7).
• Fig 2 shows the same elements, except for a nut (8), aimed at the end piece (5), which has an annular groove (4), for a seal.
• FIG. 3 there is shown a tip (5) having, on the lateral surface of the frustoconical part (6), two rings (6a) of triangular section of 0.3 mm in height.
• the method according to the invention introduces, in the vicinity of the connection 2/6, a densification of the porous tube, which locally increases its mechanical characteristics (hardness, resistance to fatigue) in this mechanically stressed area.
• connection allows the connection to be made in which the nut (8) has a transverse size significantly greater than the diameter of the porous tube (2) which does not allow the connection to be easily made during sintering (complex compression tools).

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Filtering Materials (AREA)
• Powder Metallurgy (AREA)
• Filtering Of Dispersed Particles In Gases (AREA)
• Filtration Of Liquid (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=9446420

Family Applications (1)

Country Status (8)

Cited By (1)

Families Citing this family (7)

Family Cites Families (12)

• 1993
  • 1993-04-20 FR FR9304870A patent/FR2704297B1/fr not_active Expired - Fee Related
• 1994
  • 1994-04-07 CA CA002138535A patent/CA2138535A1/fr not_active Abandoned
  • 1994-04-07 WO PCT/FR1994/000390 patent/WO1994024476A1/fr not_active Application Discontinuation
  • 1994-04-07 BR BR9405149A patent/BR9405149A/pt not_active Application Discontinuation
  • 1994-04-07 US US08/338,525 patent/US5564755A/en not_active Expired - Fee Related
  • 1994-04-07 JP JP6522815A patent/JPH07508336A/ja active Pending
  • 1994-04-07 EP EP94913145A patent/EP0646226A1/fr not_active Ceased
  • 1994-12-19 FI FI945951A patent/FI945951A/sv not_active Application Discontinuation

Non-Patent Citations (1)

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