Explosion-proof lighting fixtures: mainly used for lighting in flammable and explosive places, including explosion-proof fluorescent lamps, explosion-proof floodlights, explosion-proof floodlights, explosion-proof endless lights, explosion-proof explosion-proof explosion-proof explosion-proof lamps, explosion-proof LED lights, explosion-proof platform lights, explosion-proof street lights, etc

Explosion proof emergency lighting fixtures: mainly used for emergency use in flammable and explosive places, divided into explosion-proof sign lights, explosion-proof emergency lighting lights, etc

Explosion proof signal lamps: mainly used for command signals in flammable and explosive places, divided into explosion-proof sound and light alarm lights and explosion-proof aviation signal lights

Explosion proof and anti-corrosion lamps: mainly used in flammable, explosive, and corrosive places: divided into increased safety explosion-proof and anti-corrosion lamps, stainless steel explosion-proof and anti-corrosion lamps, etc

Design of explosion-proof lighting fixtures

When designing the structure of explosion-proof lighting fixtures, manufacturers often focus on the appearance and strength design of the explosion-proof shell, but often overlook the design of fasteners, lead-in devices, transparent components, suspension devices, signs and other components that form an integral part of the shell. Below, according to the requirements of GB3838.2-2000 "Electrical Equipment for Explosive Gas Atmospheres - Part 1: Flameproof Type" d ", some issues that need to be noted in structural design are analyzed:

⑴ Housing fasteners

There are two types of flameproof shells fastened with bolts: flat and closed. For planar structures, bolts not only perform tightening operations, but also ensure planar clearance. For the sealing structure, when the explosion-proof surface only considers the cylindrical part, the bolt only plays a tightening role; When the flameproof surface needs to consider adding a flat surface to the cylinder, the bolt not only plays a tightening role, but also ensures the clearance of the flat part. When directly tapping threads on the casing, it must be noted that the screw holes of fasteners should not pass through the explosion-proof casing as much as possible. When passing through the casing, there should be a margin of more than 3mm at the bottom of the screw holes; When using light alloy materials such as aluminum alloy as explosion-proof shells, due to the low strength of aluminum alloy, when using screws to fasten the explosion-proof shell that is frequently opened (such as replacing the light source), threads should not be directly tapped on the aluminum alloy shell. Instead, anti loosening inner and outer threaded steel sleeves should be embedded to increase the strength of the screw holes and prevent failure due to thread decay; The bolts that do not need to be opened by the user during light source replacement or maintenance, and have already been installed at the factory, can be directly tapped and tightened on the casing, but fine thread cannot be used. Coarse thread should be used as much as possible, and there should be enough engagement buckles to meet the tightening requirements.

In summary, when designing shell fasteners, it is important to first distinguish their role in the flameproof shell, whether they only serve as fasteners or whether they not only serve as fasteners but also ensure plane clearance. Then, the maximum axial load of the bolts should be determined and appropriate bolts should be selected.

⑵ Introduction method

The introduction of cables and wires can be connected in two ways:

a) Indirect introduction, connected through junction boxes or plug-in devices;

b) The connection method of directly introducing cables and wires into the main casing. It is worth noting that when the sealing ring is aged or not tightly pressed, it can directly generate combustion or explosion.