Explosion-proof light fixtures are generally classified according to the selected light source, explosion-proof structure type and use method. According to the light source classification, there are explosion-proof incandescent lamps, explosion-proof high-pressure mercury lamps, explosion-proof low-voltage fluorescent lamps, mixed light source lamps, etc.; according to the type of explosion-proof structure, there are explosion-proof light fixtures, increased safety lamps, composite lamps, etc.; explosion-proof light fixtures and portable explosion-proof light fixtures.
According to the type of explosion-proof light fixtures, it is divided into five main types: flameproof type, increased safety type, positive pressure type, non-sparking type and dust explosion-proof type.
1. Flameproof type d
Enclose all parts of the equipment that may ignite explosive gas mixtures in an enclosure, the enclosure can withstand any joints or structural gaps through the enclosure, the flammable mixture that penetrates into the enclosure explodes internally without damage, and can ensure that the energy of the internal flame gas is reduced when it propagates through the gap, which is not enough to detonate the gas of the outer casing.
2. Increased safety e
Electrical equipment that does not produce arcs and sparks under normal operating conditions takes some additional measures to improve its safety and prevent the possibility of dangerous temperatures, arcs and sparks from its internal and external components. Take protective measures to improve the reliability and safety of the equipment.
3. Positive pressure type p
By maintaining the inside of the equipment enclosure, the pressure of the shielding gas is higher than the pressure of the surrounding explosion-proof environment, to safe electrical equipment inside the system to protect static positive pressure or maintain a continuous flow of air or inert gas to limit the entry of flammable mixtures into the interior of the enclosure. Take away the flammable gas that enters the casing when the equipment is not under positive pressure to prevent the formation of flammable mixtures in the casing.
4. Intrinsically safe type I
All circuits inside the equipment are under standard specified conditions (including normal operation and specified fault conditions), and any spark or any effect generated cannot ignite the intrinsically safe circuit of the specified explosion-proof gas environment.
5. Pouring type m
The electrical components that may generate sparks, arcs or dangerous temperature parts that may ignite the explosion of the explosive mixture are encapsulated in a potting agent (compound) so that it cannot ignite the surrounding explosive mixture. The use of potting measures can prevent short circuit of electrical components, solidify electrical insulation, avoid sparks on the circuit and ignition of arcs and dangerous temperatures, prevent the intrusion of explosive mixtures, and control the surface temperature under normal and fault conditions.