Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02B—BOARDS, SUBSTATIONS OR SWITCHING ARRANGEMENTS FOR THE SUPPLY OR DISTRIBUTION OF ELECTRIC POWER
  • H02B1/00—Frameworks, boards, panels, desks, casings; Details of substations or switching arrangements
  • H02B1/26—Casings; Parts thereof or accessories therefor
  • H02B1/28—Casings; Parts thereof or accessories therefor dustproof, splashproof, drip-proof, waterproof or flameproof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/11—Making porous workpieces or articles
  • B22F3/1121—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers
  • B22F3/1125—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers involving a foaming process
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
  • B22F3/10—Sintering only
  • B22F3/11—Making porous workpieces or articles
  • B22F3/1121—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers
  • B22F3/1137—Making porous workpieces or articles by using decomposable, meltable or sublimatable fillers by coating porous removable preforms
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C1/00—Making non-ferrous alloys
  • C22C1/08—Alloys with open or closed pores
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
  • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
  • B22F2998/10—Processes characterised by the sequence of their steps

Definitions

• the invention relates to a housing according to the preamble of patent claim 1.
• Loudspeakers or other electrically operated devices that are supplied with electrical energy must be protected in a special way in a potentially explosive atmosphere.
• One of the most common types of protection is the explosion-proof "Flameproof Enclosure” design, which allows loudspeaker operation in hazardous gas atmospheres Advanced versions of "Flameproof Enclosures" are covered by the new European standard IEC 60079-1: 2003 (EN 60079-1: 03.2004) allows.
• a method for guiding explosion gases formed inside an explosion-proof housing is already known, in which the amount of gases entering columns of the housing is reduced by flow dividers (DE 198 26 911 C2).
• flow dividers can also be provided with flame arresters relief openings.
• a passage for cooling water in which passage a pressure-resistant lock is arranged (DE 101 52 510 B4).
• the pressure-resistant lock in this case has a plurality of passage channels whose cross-sectional and length dimensions are selected so that an ignition breakdown of the housing interior is prevented by the barrier to the outside.
• a closed, explosion-proof housing for receiving electrical components which has an opening which is closed by means of a porous sealing plug (EP 0 157 285 B1).
• a disc made of porous material is provided as a pressure equalization device (DE 8409 870.8 U).
• a disk is for example a porous ceramic disk, a sintered filter or a close-meshed wire mesh.
• the object of the invention is to arrange entire subassemblies in a potentially explosive atmosphere in such a way that an explosion which may occur in the subassemblies does not propagate.
• the invention thus relates to a housing for an electrically operated device, wherein this housing is located in a potentially explosive environment.
• the housing is made of a material that is gas permeable and non-flammable. As a suitable material comes z. As metal foam in question.
• the advantage achieved by the invention is, in particular, that the pressure increase is attenuated by an explosion occurring in a housing through the housing itself.
• FIG. 1 shows a cylindrical housing made of porous open-pored material
• 2 shows a section through the housing according to FIG. 1
• Fig. 3 is a lamp with a pressure-resistant housing.
• a cylindrical housing 1 which has a cylindrical part 2, which is closed with a cover 3.
• the cylindrical part 2 and the lid 3 consist of a porous porous material, such as sintered metal or a metal foam.
• the lid 3 is connected by means of two screws 4, 5 with the cylindrical part 2. Of course, instead of two screws, several screws can be provided.
• a connection 6 is provided for the supply of an electrical voltage.
• a longitudinal section through the housing 1 is shown. It can be seen here that a loudspeaker 7, which is connected to an electrical component 8 via lines 9, 10, is located in the interior of the housing 1. The component 8 itself is connected via lines 11, 12 to the terminal 6. The pressure-resistant interior 13 of the housing 1 is thus separated by the housing 1 of the explosion-hazard outdoor space 14. Sound waves 15 indicate that the material of the cylindrical part 2 is sound permeable. Instead of a loudspeaker and other sounder, z. B. ringing or other electrically acting devices may be provided.
• the material thickness, pore size and density must be optimized accordingly, but only in compliance with the already described functionality of the explosion protection.
• the methods for determining pore size and density are specified in ISO 4003 and ISO 4892.
• the safe wall thickness is to be proven depending on the pore size according to IEC 60079-1: 2003 (EN 60079-1: 03.2004).
• the material may be aluminum or nickel foams or steel foam.
• the production processes for metal foams are subdivided into melting and powder metallurgical processes as well as in coating processes.
• Aluminum foams are known, for example, under the names Duocel, Alporas and Formgrip, while Nickel regarding. Nickel chrome foams are known under the name Incofoam.
• the porosity can be open or closed.
• Duocel has an open porosity of 88% to 98%.
• Incofoam also has an open porosity of 91% to 98%.
• Alporas has a closed porosity of 91% to 93%.
• a short circuit occurs in the component 8, which may contain, inter alia, an amplifier, or a short circuit between the lines 9, 10, then parts of the gas present in the interior space 13 will first ignite. This results in the interior 13, a pressure increase.
• This pressure increase causes gases, which are located in the interior 13 of the housing 1, are pressed through the porous open-pore walls of the housing 1 in the outer space 14.
• the material that makes up the housing also has a cooling effect on the escaping gases that are so large is that in the outer space 14, the ignition temperature of the gas located there is not reached.
• FIG. 3 shows a flashing light 30 which has a flash tube 31 with a glass dome 45 surrounding it.
• the flash tube 31 is connected to an electrical component 32, which is enclosed in the vertical direction by a cylindrical housing 33, which has a cover 34 on its underside. 35 denotes a cable entry, from which electrical leads 36, 37 lead to the insert 32.
• a pressure-resistant space 38 is formed.
• the normative known ignition-puncture-proof gap is also determined here by the shape and sizes of the pores.
• the glass cap 45 has at the lower end an annular horizontal extension 39, between which and the housing 33 is a firmly adhering seam 40 is located.
• the cover 34 has a directed into the space 38 approach 41, which forms a parting plane 42 between this approach 41, the lid 34 and the housing 33.
• the cover 34 is connected to the housing 33 via screws 43, 44.
• the housing 33 and the lid 34 are made of foamed, pressed or porous porous materials. If z. Example, a metal foam used, this can be prepared approximately by the fact that a crosslinked polyurethane foam coated with nickel and then the polyurethane is removed by thermal decomposition. Optionally, then the nickel can be converted into a nickel-chromium alloy.
• SRSS-iron slip-reaction-foam-sinter
• SRSS slip-reaction-foam-sinter
• the foaming is generated by a chemical reaction that takes place at room temperature.
• the solid components a metal powder and a dispersant, e.g. Phyllosilicate, mixed.
• a blowing agent in the form of a very fine reactive metal powder, e.g. Carbonyl iron, added.
• concentrated phosphoric acid is added to the solvent - water and / or alcohol - whereby the acid dissociates in water.
• a silty suspension is formed in which two reactions take place in parallel:
• the built-in part 32 may be an ignition source for gas mixtures located in the pressure-resistant space 38. In the case of an internal explosion, it does not build up the maximum reference pressure, but to an immediate reduction of the explosion pressure, because the device walls are gas permeable.
• the housing surrounds at least the electrical component, not only a surrounding housing on all sides is understood, but - as shown in FIG. 3 - also encompassing in only one direction. This direction is the vertical direction in the example of FIG. It could also be the horizontal direction. It is only important that the electrical component 8, 32 does not protrude from the housing.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Power Engineering (AREA)
• Casings For Electric Apparatus (AREA)
• Powder Metallurgy (AREA)
• Diaphragms For Electromechanical Transducers (AREA)
• Soundproofing, Sound Blocking, And Sound Damping (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37635920

Family Applications (1)

Country Status (5)

Families Citing this family (11)

Family Cites Families (10)

• 2005
  • 2005-09-08 DE DE102005042565A patent/DE102005042565B4/de not_active Expired - Fee Related
• 2006
  • 2006-08-18 US US12/063,690 patent/US20110002494A1/en not_active Abandoned
  • 2006-08-18 WO PCT/EP2006/008153 patent/WO2007028492A1/de active Application Filing
  • 2006-08-18 EP EP06791589A patent/EP1922792A1/de not_active Withdrawn
  • 2006-08-18 RU RU2008105078/03A patent/RU2409014C2/ru not_active IP Right Cessation

Non-Patent Citations (1)

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