Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V23/00—Arrangement of electric circuit elements in or on lighting devices
  • F21V23/02—Arrangement of electric circuit elements in or on lighting devices the elements being transformers, impedances or power supply units, e.g. a transformer with a rectifier
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V25/00—Safety devices structurally associated with lighting devices
  • F21V25/12—Flameproof or explosion-proof arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V15/00—Protecting lighting devices from damage
  • F21V15/01—Housings, e.g. material or assembling of housing parts
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
  • F21V29/50—Cooling arrangements
  • F21V29/70—Cooling arrangements characterised by passive heat-dissipating elements, e.g. heat-sinks
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
  • F21V29/85—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems characterised by the material
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V29/00—Protecting lighting devices from thermal damage; Cooling or heating arrangements specially adapted for lighting devices or systems
  • F21V29/90—Heating arrangements
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F21—LIGHTING
  • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
  • F21V31/00—Gas-tight or water-tight arrangements
  • F21V31/04—Provision of filling media

Definitions

• the present invention relates to an explosion-proof lighting fitting comprising a branch box, a mounting element, a light- transmitting screen and a housing which accommodates the lamp and the required electronic components.
• Such an explosion-proof lighting fitting is preferably used in areas where there is a risk of explosion and in areas where the environment presents large problems, for example a corrosive, acidic or salty or other aggressive environment.
• a lighting fitting of the above type can be used indoors as well as outdoors at various locations, such as petroleum refineries, chemical and petrochemical plants, oil drilling platforms and other process industry facilities where there are similar risks.
• a construction as described above makes it possible to use these lighting fittings in areas which constitute a danger, due to the presence of inflammable vapours, gases or highly inflammable dust flows.
• French patent publ ication 2246812 relates to a warning lamp for use in harzardous atmosphere comprising a holow base member, a plate member within the hollow base member and a transparant light- focussing dome mounted on said plate member and surrounding a gas discharge lamp.
• electrical control means are encapsulated in a potting compound within said hollow housing there is still a risk of the generation of condensation water within said housing.
• U.S. patent 5,528,474 relates to a LED array vehicle lamp wherein the LEDs and circuit boards are fully embedded in a resin material cured with thermally conductive particles suspended therein for conducting excess heat to the outer aluminum housing and the outer environment. As such, the temperature of the LEDS may be kept sufficiently cool to prevent degradation of the brightness of the lamp.
• German Offenlegungsschrift 4017654 relates to a hand held lamp wherein the heat generated by the lamp is dissipated via cooling fins located on the outside of the housing.
• a lighting fitting of the above kind is for example known from European patent application Nr. 0823589.
• the lighting fitting disclosed therein is only suitable for one or more light-emitting diodes (LED) which are fitted in a construction provided with a light-transmitting screen, through which the status of the LED can be observed.
• European patent application Nr. 0 695 909 relates to an explosion-proof lighting fitting as referred to in the introduction.
• the drawback of such a lighting fitting is the fact that the heat generated by the lamp is not dissipated to a sufficient degree, so that the life of such a construction is adversely affected.
• European patent application Nr. 0 598 724 relates to an explosion-proof lighting fitting for use in explosive atmospheres.
• Such a 1 ighting fitting comprises a housing provided with a cover plate, wherein the problem of the heat generated by the lamp is solved by providing fins or ribs.
• the object of the present invention is to provide an explosion-proof lighting fitting, which eliminates the above-descri ed drawbacks of the cited prior art documents.
• Another object of the present invention is to provide an explosion-proof lighting fitting, which is also suitable for use in humid conditions.
• Another object of the present invention is to provide a lighting fitting which can be used within wide temperature limits, namely from -50 °C to +52 °C.
• Another object of the present invention is to provide an explosion-proof lighting fitting of robust construction, which is resistant to external magnetic force fields, which is resistant to vibrations and shocks and which enables a maintenance-free period of at least 100,000 hours.
• the above objectives and further advantages are accomplished by an explosion-proof lighting fitting as referred to in the introduction, which explosion-proof lighting fitting is according to the present invention characterized in that the lamp is placed on a baseplate within the housing, which baseplate functions to dissipate the heat generated by the lamp and that a heating element is provided in the space enclosed by the housing.
• the heat conducting baseplate is made of a metal , which metal is preferably coated with a slightly light- reflecting material on at least one side thereof, in particular the upper side.
• a baseplate ensures that the heat generated by the lamp is dissipated, so that no accumulation of heat will take place within the lighting fitting.
• the advantageous dissipation of the generated heat considerably prolongs the life of the lamp, whereby it should also be mentioned that the occurrence of stresses in the housing is prevented.
• the use of the baseplate according to the present invention does not have an adverse effect on the light output of the lamp, due to the use of a light-reflecting material.
• the baseplate consists of nickel-plated copper. Copper is a material which has a high heat conducting coefficient and the nickel which is plated thereon ensures that the light output of the lamp is not adversely affected by the presence of such a baseplate, due to the fact that the light is reflected by the nickel layer
• the baseplate in a special embodiment it is furthermore preferred for the baseplate to extend radially up to the edge of the housing.
• the heat generated by the lamp is thus evenly distributed over the baseplate, so that no stresses will be induced in the material. Moreover, in this manner the heat dissipating properties of the metal being used are util ized optimally.
• the moulding resin In order to prevent condensation within the housing, it is preferred to encapsulate the electronic components that are present in a moulding resin.
• Another special function of the moulding resin is that is also functions as a heat dissipating medium.
• a heat conducting material in particular metal particles
• the amount of iron is preferably at least 10 g/kg of moulding resin. If the amount of iron is less than 10 g/kg of moulding resin, the intended effect, in particular the increasing of the thermal capacity of the moulding resin, will be insufficient.
• the use of the moulding resin also ensures the explosion safety.
• the generation of heat in the explosion-proof lighting fitting according to the present invention will be regulated advantageously both by the heat conducting baseplate and by the moulding resin, to which a heat conducting material has been added in a special embodiment.
• a heat conducting material in particular iron particles
• a latex layer also performs a function as regards the prevention of condensation.
• the problem of the generation of heat is thus solved by the special combination of the above-described measures, namely the baseplate, the latex-like sealing of the electronic components and the encapsulation of the electronic components in a moulding resin to which a heat conducting material may have been added.
• the present invention is not limited to the simultaneous use of the above measures, however.
• the light- transmitting screen is seal ingly connected with the housing, using a spacer and a sealing material.
• the light-transmitting screen is made of a shock-resistant glass, and in order to increase the sealing action, a spacer is placed between the contact surface of the housing and the light-transmitting screen. Since the baseplate extends radially up to the edge of the housing in a special embodiment, the spacer is positioned on said radially extending baseplate.
• a suitable sealing material is for example a sealing material with a base of silicone. For special uses it is desirable to use a coloured light-transmitting screen.
• a reflector in the space enclosed by the baseplate and the light-transmitting screen, between the lamp and the baseplate.
• the reflector preferably extends radially up to the light-transmitting screen with a view to increasing the light reflection output.
• the reflector is slightly concave at its end, which concave shape functions to ensure that the light emitted by the lamp is reflected in the desired direction.
• Suitable materials for the reflector are for example polished stainless steel or anodised aluminium. It is also possible, of course, to use such a reflector in a lighting fitting which does not need to satisfy any explosion safety requirements.
• the branch box separate from the housing, wherein the branch box is preferably connected to the housing via the mounting element.
• the explosion-proof lighting fitting will be readily accessible upon repair and/or replacement of special parts.
• an authorized person for example an electrician, can make the desired electrical connection only in the separate branch box. Since it is not possible to access the lighting fitting, in particular the housing, the electrician is efficiently prevented from influencing the specific characteristics of the lighting fitting, as a result of which it would no longer meet the requirements of explosion safety and water tightness. Furthermore, a simple and robust construction is obtained in this manner.
• the explosion-proof lighting fitting according to the present invention is suitable for use in the offshore industry, refineries, the chemical industry and at locations which are difficult to reach, for example airfields or helicopter landing sites.
• the lighting fitting according to the present invention is in particular suitable for a type QL lamp which is marketed by Philips. By using such a lamp and the explosion-proof lighting fitting according to the present invention, a lighting level corresponding to a 2x 36 Watt EEX strip lighting fitting can be obtained.
• Such a capacity makes the explosion-proof lighting fitting according to the present invention suitable in particular for use at a height of 3 - 6 metres.
• the construction according to the present invention is so robust that the industrial explosion-proof 1 ighting fitting according to the present invention does not require any maintenance for more than 100,000 hours in very demanding conditions.
• Figure 1 is a perspective front view of a special embodiment of an explosion-proof lighting fitting according to the present invention.
• Figure 2 is a schematic, cross-sectional view of the explosion-proof lighting fitting which is shown in Figure 1.
• Figure 3 is a schematic plan view of the explosion-proof lighting fitting according to the present invention.
• Figure 1 is a perspective front view of the explosion- proof lighting fitting according to the present invention.
• Housing 14 is connected on its bottom side to two mounting elements 13, with branch box 7 being secured to one of said mounting elements 13.
• Branch box 7 is provided with a union 8.
• Housing 14 (base part) is connected to housing 15 (cover part), in which cover part the light-transmitting screen 1 is sealingly provided.
• the connection between light-transmitting screen 1 and housing 15 (cover part) is shown in more detail in Figure 2.
• the explosion-proof 1 ighting fitting as shown in Figure 1 furthermore comprises a reflector 16, which reflector 16 is positioned between lamp 2 and baseplate 3.
• the explosion-proof lighting fitting 1 according to the present invention is by no means limited to the use of such a reflector 16, however.
• FIG 2 schematically shows a cross-section of the explosion-proof 1 ighting fitting of Figure 1.
• Electronic components holder 12 is disposed within the housing (base part) 14 (refer in particular to Figure 3) and comprises an explosion-proof bottom plate 11, in particular also called explosion-proof cover, with electronic components holder 12 being enveloped in a latex layer (not shown).
• Electronic components holder 12 is furthermore encapsulated in a moulding resin 10, to which moulding resin 10 a heat conducting material has been added in a special embodiment.
• Light-transmitting screen 1 is placed on baseplate 3, using spacer 6. By placing light-transmitting screen 1 on spacer 6 and subsequently forming a hermetic seal, using sealing material 4, 5, a condensation-free and moisture-free lighting fitting is formed.
• Light-transmitting screen 1 is sealingly connected to housing 15 (cover part), wherein likewise a reflector 16 is used with a view to increasing the light output of lamp 2.
• FIG 3 schematically shows a plan view of the explosion-proof lighting fitting of Figures 1 - 2.
• Figure 3 clearly shows the tape heating element 17, which tape heating element 17 is preferably present on the circumference of housing 14.
• moulding resin 10 is provided with a heat conducting material (not shown).
• the electronic components holder 12 is enveloped in a layer of protective material 18, in particular a latex layer.
• Branch box 7 is provided with terminals 19, which branch box 7 is secured to mounting element 13, which mounting element 13 is connected to housing 14 (base part).
• two mounting elements 13 are preferably connected to bottom plate 11.
• the use of the explosion-proof lighting fitting as described in Figures 1 - 3 makes it possible to achieve a lighting fitting efficiency of 90%.
• the special construction of the tape heating element, the moulding resin, the latex-1 ike seal and the baseplate makes it possible to use the explosion-proof lighting fitting according to the present invention within a temperature range of -50 °C to +52 °C.
• the present lighting fitting is by no means limited to the special combination of the above-described measures, however.
• the present embodiment prolongs the 1 ife of the 1 ighting fitting.
• the electrical connections which are provided in a separate branch box facilitate the making of the electronic connections.
• the explosion-proof lighting fitting according to the present invention is in particular suitable for use in the offshore industry, refineries, the chemical industry and as a lighting device to be used at helicopter landing sites and all locations which are difficult to reach, such as access doors to storage spaces and the like.
• the explosion-proof lighting fitting according to the present invention is furthermore suitable for use as obstruction light.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)
• Materials For Medical Uses (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=19767147

Family Applications (1)

Country Status (6)

Cited By (3)

Families Citing this family (2)

Citations (9)

• 1998
  • 1998-05-18 NL NL1009187A patent/NL1009187C2/nl not_active IP Right Cessation
• 1999
  • 1999-05-12 DE DE69915053T patent/DE69915053T2/de not_active Expired - Lifetime
  • 1999-05-12 AT AT99922652T patent/ATE260439T1/de not_active IP Right Cessation
  • 1999-05-12 AU AU39602/99A patent/AU3960299A/en not_active Abandoned
  • 1999-05-12 EP EP99922652A patent/EP1078202B1/en not_active Expired - Lifetime
  • 1999-05-12 WO PCT/NL1999/000293 patent/WO1999060304A1/en active IP Right Grant

Patent Citations (9)

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