in fact,Explosion proof certificationIt is a necessary test for most electrical products to pass and obtain certification certificates. This is not only a guarantee and promotion of product quality, but also makes customers feel more at ease when using it. The country isExplosion proof certificationThere are also strict standards.
The concept of explosion prevention
Explosion requires certain prerequisites.
1. There are explosive substances (flammable) present
2. Form an explosive mixture within a certain space, with a concentration within the explosive limit of the gas; (Adequate oxygen)
3. It is an ignition source, and its energy must be greater than the minimum ignition energy of the explosive mixture (reaching the ignition point)
Explosion can only occur when it exists simultaneously in a certain area, which is the so-called explosion triangle principle. What we need to do is to control one or more of these three conditions. Oxygen and explosive substances objectively exist in explosive environments, so we need to control objects (and detonation sources) working in explosive hazardous environments, which is called explosion prevention.
The significance of explosion prevention
Explosive substances: Many production sites produce some flammable substances. About two-thirds of the underground coal mine contains explosive substances; In the chemical industry, about80% of production workshop areas have explosive substances. Oxygen: Oxygen is everywhere in the air. Ignition source: Electrical instruments, various friction electric sparks, mechanical wear sparks, electrostatic sparks, high temperatures, etc. are widely used in the production process, especially in the event of instrument and electrical failures.
Objectively speaking, many industrial sites have met the conditions for explosion. When the mixed concentration of explosives and oxygen is within the explosive limit, if there is an explosive source, an explosion will occur. Therefore, it is necessary to take explosion-proof measures.
Explosion proof grade description.
IA level: Electrical equipment cannot ignite explosive gas mixtures during normal operation.
During normal operation, the safety factor is2.0；
When there is a malfunction, the safety factor is1.5；
In the event of a secondary malfunction, the safety factor is1.0.
Note: Contact points with sparks must be equipped with explosion-proof enclosures. Airtight casing or doubling to increase safety factor.
IB level: Electrical equipment that cannot ignite explosive gas mixtures during normal operation and malfunction.
During normal operation, the safety factor is2.0；
When a malfunction occurs, the safety factor is1.5. During normal operation, the spark contact must protect the explosion-proof shell or airtight shell and take measures to self display faults. When there is a malfunction, the safety factor is 1.0.
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