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How to design and manufacture a good flameproof type explosion-proof lamp

CESP Ex Wiki Wednesday, 15 June 2022 07:29

The explosion-proof lamps of flameproof type is mainly in the product structure, with a certain explosion-proof joint surface or explosion-proof thread, through an integral explosion-proof shell, to withstand the explosion pressure of the explosive mixture that may be generated inside the lamp, And prevent the explosion to the surrounding explosive mixture to achieve explosion-proof purposes.

 flameproof lighting

Flameproof Type Explosion Proof LED Light CES-EX-LN Series

“10mm-thick tempered glass + ADC12and 6063 aluminum housing for CES-EX-LN explosion proof led linear light is shock-resistant, anti-vibration, can withstand 7J impact, and is equipped with micro-light elements to reduce direct visual contact with the light source, prevent glare, and replace the old and prone to failure Fluorescent light fixtures.


Part. 1 The explosion-proof principle of flameproof lamps

Flameproof explosion-proof lamps, which can be used with a power supply not exceeding 1000V include incandescent lamps, tungsten halogen lamps, fluorescent lamp (including compact fluorescent lamps), high-pressure mercury lamps, high-pressure sodium lamps, self-ballasted high-pressure mercury lamps and metal halide lamps, etc. . Its structural characteristics are first of all that it must have a device that can withstand the requirements of IEC 60079-1 "protected by a flameproof enclosure "d". This integral flameproof enclosure, including the lamp body parts and Equipped with this, there are two parts of transparent parts such as a solid lampshade. According to the shape of the light source and the distribution of the illuminants, common flameproof lamps can be generally classified into vertical lamps equipped with gas discharge light sources such as incandescent lamps and high-pressure mercury lamps, and horizontal lamps equipped with straight fluorescent bulbs. There are two basic types of lamps. Its common components are lamp body, transparent parts, sealing parts, lamp sockets, inner reflectors and outer lamp umbrellas. The judgment of a good flameproof lamp mainly depends on the reasonable structure of the lamp body and the matching flameproof joint surface, the transparent part that can withstand the impact test and the thermal shock test, and the rubber seal with strong anti-aging ability. The lamp body is fixed with the transparent part, and then equipped with a lamp holder with reliable electrical performance. Through the reasonably designed inner reflector and outer lamp umbrella, the luminous flux of the light source inside the lamp can be irradiated to the outside of the lamp through the transparent part to the maximum extent, and the danger of explosion is caused. Ideal lighting effect for places. How to organically combine these components and make a reasonable layout is the key to the design and development of flameproof and explosion-proof lamps at present and in the future.


Part.2 Basic requirements for flameproof enclosures of lamps

For flameproof lamps, the flameproof enclosure is the key component of this type of flameproof explosion-proof electrical equipment, so the flameproof enclosure must meet the general requirements and special requirements for flameproof performance.

  1. General requirements
  • Explosion proof lamps are special lamps and must meet the general requirements of ordinary lamps.
  • The shell shape of the lamp strives to be beautiful, compact and reliable, light and good in craftsmanship.
  • Sufficient volume is required to place electrical components such as lamp sockets, bulbs, reflectors, binding posts, and lighting accessories. At the same time, the rationality of the layout should be considered to facilitate installation, replacement of light sources, and other use and maintenance.
  • There must be a transparent part with a certain surface area, so that the luminous flux of the light source inside the lamp can be effectively projected through the reflective part.
  • To comprehensively consider measures such as heat dissipation, dustproof, waterproof and anti-corrosion, and give sufficient guarantee on the structure.
  • In the appropriate position, the internal and external grounding shall be arranged reasonably, and there shall be corresponding permanent grounding signs.


  1. Special requirements

The national explosion-proof standard of flameproof enclosure requires that it can withstand the explosion pressure of the internal explosive gas mixture and prevent the internal explosion flame from spreading to the explosive mixture around the enclosure; to meet this performance, the following special requirements must be specifically considered:

  • Anti-explosion performance. The shell of the lamp is required to have sufficient strength and rigidity to withstand the explosion pressure that may be caused by the inner cavity of the lamp. Therefore, appropriate materials and wall thicknesses should be selected to form a perfect three-dimensional geometry distribution. This cavity structure should be both beautiful and generous. Uneven stress caused by excessive shape changes should be avoided as much as possible in order to ensure that the dynamic strength test specified in IEC 60079-1 can finally be passed.
  • Flameproof function. When designing the flameproof enclosure of the lamp, it is necessary to select the appropriate flameproof joint surface structural parameters, the way of introducing the device, the sealing structure of the transparent part and the lamp body part, and the roughness of the flameproof joint surface in strict accordance with the provisions of IEC 60079-1. In order to effectively prevent the internal explosion flame from propagating to the explosive mixture around the enclosure, it finally passes the flameproof performance test specified in IEC 60079-1.
  • The flameproof shell of lamps is mostly composed of 2 or more connected cavities, which is prone to pressure overlap. Generally speaking, this will cause the explosion pressure to rise abnormally and sharply and exceed the expected maximum pressure. To this end, the area of the communication hole should be increased as much as possible, so that the shape of the inner casing can eliminate the pressure overlapping phenomenon. If the phenomenon of pressure overlap cannot be eliminated in practice, explosion-proof measures should be taken between the chambers to eliminate pressure overlap.
  • For IIC flameproof lamps, IEC 60079-1 strictly stipulates that the plane flameproof joint surface whose flameproof gap tends to increase during explosion should not be used. The structure of the thread is used, so that the lamp cavity can be opened smoothly when the lamp is replaced or repaired.


flameproof hand lamp

Flameproof Proof LED Hand Lamp CES-EX-SC Series (ATEX / IECEx Zone 1)

“Durable, corrosion-resistant, and has undergone extreme hydraulic and heavy pressure tests and can withstand 7J impact. It has the characteristics of small size, light weight, portable etc. No hot when operate at the highest temperature, internal locking can prevent the cable from pulling out. can be used in hazardous areas Zone 1&21, Zone 2&22.


Part.3 Design, manufacture and installation of transparent parts of flameproof lamps

As a flame-proof type explosion-proof lamp, there must be a certain light-transmitting part. At present, our country is basically made of glass material and is fixedly installed on the cavity of the explosion-proof lamp. Therefore, these glass transparent parts of flameproof lamps must not only meet the impact test and thermal shock test requirements of the transparent parts in the general requirements of IEC 60079-0, but more importantly, they must withstand the requirements specified in IEC 60079-1. Dynamic Strength Test. This requires that these transparent glass parts need to have sufficient strength, that is, they must have sufficient thickness and a certain geometric distribution, and undergo processing such as tempering. When designing transparent glass parts, we must pay attention to the reasonable selection of glass thickness and the determination of shape. Everything is premised on avoiding uneven stress in the finished product of the transparent parts, and at the same time, it is necessary to ensure that there is no sudden change in thickness. The main advantages of glass are that it can maintain its physical and light transmission properties under high temperature, ultraviolet radiation and long-term humid conditions, the surface is resistant to scratches by hard particles, and it is allowed to be immersed in aqueous or organic solvents without causing stress. cracks or corrosion. The main disadvantage of glass is its brittleness and low tensile strength. In order to make up for these shortcomings, when designing the assembly structure of the glass transparent part and the lamp body, a gasket is usually inserted between the glass transparent part and the metal parts of the lamp housing to prevent point contact with the metal parts of the housing and damage the glass transparent part. In order to prevent the impact of solid foreign objects from breaking the glass transparent parts, the commonly used method is to add a grille to protect it. If no grille grille is installed, the glass transparent parts must pass the high energy impact test specified in IEC 60079-0.

Generally, when the transparent parts of flameproof lamps adopt a sealed structure, the thickness of the gasket shall not be less than 2.0mm, and the width of the embedded part of the gasket between the metal shell and the glass transparent part shall not be less than 10.0mm. At the same time, glass transparent parts should generally be installed in the inner cavity, because when there is pressure inside, the elastic gasket tends to be compressed, which will strengthen the sealing performance. The material of the elastic gasket is generally made of nitrile rubber; when the power of the lamp is large, asbestos rubber sheet or silicone rubber, fluorine rubber and other materials that are self-extinguishing from fire can be used. It must also be noted that when installing the glass transparent parts, measures should be taken to ensure that the perimeter of the lampshade, glass tube and transparent plate should be compressed structurally, and the force should be uniform to avoid causing dangerous mechanical stress inside the transparent parts. For the glass transparent parts of explosion-proof lamps, it can also be sealed and fixed by direct glue sealing with the shell lamp body. This structure has higher requirements on the sealing material, and silicone rubber is suitable. The fixing of the transparent part of the luminaire and the housing part must be ensured in structure that when the light source is replaced, the transparent part and the sealing part shall not fall off the housing part.


Part.4 Selection of the introduction method of explosion-proof lamps

The introduction method of flameproof lamps is clearly stipulated in IEC 60079-1, that is, indirect introduction methods are required for lamps, but direct introduction methods can be adopted for Class I fluorescent lamps with flameproof lamp sockets and cold-start fluorescent lamps. This regulation of the introduction method is mainly due to the fact that it is impossible to completely avoid the generation of sparks, arcs or dangerous temperatures inside the explosion-proof lamps during normal operation. The indirect introduction method is to electrically connect the lamp with cables or wires through the junction box or plug, and the lamp is divided into two independent cavities in structure, the main cavity of the lamp and the wiring cavity, that is, the two-chamber explosion-proof cavity. Structure, so that the reliability of explosion-proof safety is fully guaranteed.


Part.5 Maintenance of explosion-proof lamps

Explosion-proof lamps are allowed to be repaired in principle, and the specific requirements are:

  1. Lamp Repair Requirements

Detachable parts of lamps and lanterns are allowed to be replaced with accessories. The accessories must be the same as the original and must meet the relevant regulations of IEC 60079-1, IEC 60079-2 and IEC 60079-7 respectively.

The replacement here is to replace the maintenance activities with accessories. Generally, non-professionals are required not to open or disassemble the flameproof lamps. The usual maintenance is mainly to replace the consumable electrical components such as the light source and the starter of the fluorescent lamp and the trigger of the gas discharge lamp. , After the installation and disassembly of the lamp, pay attention to whether the gasket between the transparent part of the lamp and the lamp body is restored to the original compressed state. If the sealing gasket is damaged, it must be replaced in time to ensure the reliability of explosion-proof performance.

  1. Replacement of lamp sockets

The lamp holder can be replaced as a whole. The explosion-proof lamp holder used for replacement must have a certificate or document approved by the explosion-proof inspection unit. The lamp holder accessories must be in good contact and have the heat resistance of the original.

The lamp holder is allowed to be replaced as a whole, mainly because the lamp holder is a complete part. The assembly of the lamp holder has many mutually restricting effects. If the parts are replaced, it will often affect the overall electrical performance of the lamp holder. The electrical conductivity and heat resistance of the socket accessories are very important. Random replacement will definitely reduce the overall performance of the lamp socket. Therefore, the requirements for the lamp socket accessories are relatively high, which is completely to avoid sparks inside the lamp. , The arc angle is considered.

  1. Ballast replacement

The ballast of explosion-proof lamps can be replaced with accessories of the same model and capacity. When changing the ballast mode, it must be approved by the explosion-proof inspection unit.

The technical performance of different types of ballasts is not exactly the same. When replacing different types of ballasts, it may cause changes in the temperature rise, insulation performance, and working performance of explosion-proof lamps. In explosion-proof lamps, this change It will definitely affect the explosion-proof level, so it is stipulated that only accessories of the same model and capacity are allowed to be replaced. When changing the ballast method, the temperature rise of the entire ballast component will change more, so the temperature rise and other tests must be re-tested. Determine the new explosion-proof level, and this kind of test identification can only be recognized after passing the test of the explosion-proof inspection unit.