Knowledges of explosion-proof electrical equipment

Explosion-proof types are categorized based on the environment in which the explosion-proof electrical equipment is utilized, the inherent characteristics of the products, as well as their safety features and structural design. These types include flameproof, intrinsically safe, increased safety, encapsulated, positive pressure, and oil-immersed equipment. The most prevalent type found is the explosion-proof electrical equipment, marked with the explosion-proof designation "d". Recent updates in the field have emphasized the importance of innovation in these classifications, enhancing the adaptability of explosion-proof electrical equipment to various hazardous environments.

During standard operations, the components of explosion-proof electrical equipment that are capable of producing sparks, arcs, or reaching dangerous temperatures are securely housed within a flameproof enclosure. This design effectively isolates the internal components from the external environment. In the case of an internal explosion, the enclosure remains intact, and the structural gaps within it help to cool the flames and mitigate their spread, ensuring explosion protection.

The categories of explosion-proof electrical equipment include:

Class I: coal mine gas

IIA: propane, methane, diesel, etc.

IIB: ethylene, ethylene glycol, etc.

IIC: acetylene, hydrogen, carbon disulfide, ethyl nitrate, etc.

Common designs for explosion-proof joints in electrical equipment include:

Plane type: The shells are joined at a flat surface to create a flameproof joint, allowing the enclosure to withstand explosion pressures from internal explosive mixtures and preventing explosion propagation into surrounding explosive environments.

Threaded type: The upper and lower shells are interconnected via threading to create a flameproof joint surface, similarly ensuring resilience against internal explosion pressures.

Cylinder type: The joining of the upper and lower shells in a cylindrical shape also forms a flameproof joint capable of withstanding internal explosion pressures.

Bonding type: Components of the flameproof enclosure are either directly bonded to the wall of the enclosure, forming integral structures, or attached to a metal frame, allowing for component replacement without compromising the bonding.

Main tests required for explosion-proof electrical equipment include:

Test compliance standards: GB/T 3836.2-2021 Articles 15.2 and 15.3

Testing parameters: Enclosure pressure tests, non-propagation ignition tests, appearance assessments, flooding tests, impact resistance evaluations, thermal cycling tests, flame ablation tests, among others.