Some common sense about explosion-proof electrical industry

About the division of dangerous areas:

We must have seen the partitions in the details of explosion-proof electrical appliances. But what exactly does this mean? I think people still do not understand it. I will explain here the division of dangerous areas.

The frequency and duration of the appearance of the explosion-proof environment of citrus in gas areas often divide the danger into different regions, namely, Zone 0, Zone 1, and Zone 2.

Zone 0: A site where explosive mixtures in an explosive atmosphere continuously appear in the form of gas, vapour or mist, or exist for long periods of time.

Zone 1: During normal operation, explosive gases in the form of gases, vapors or mists may be present in explosive atmospheres. A zone is a typical application for explosion-proof electrical equipment.

Zone 2: In normal operation, explosive mixtures in the form of gases, vapours, or mists are unlikely to occur in explosive atmospheres and, if present, occur only occasionally and for a short period of time. Usually, "short time" means that the duration is not more than 2 hours.

Dust sites are divided into three zones: Zone 20, Zone 21, Zone 22 and Zone 20: Combustible dust continues to occur during normal operation or often occurs in quantities sufficient to form a combustible dust and air mixture or may become uncontrollable and thick Dusty place and inside of the container.

Zone 21: During normal operation, there may be dust that is sufficient to form a mixture of flammable dust and air but is zoned to zone 20. This area includes flammable dust and air mixture sites with flammable concentrations that are likely to occur adjacent to the space where dust is discharged, where there is a dust layer, and in the normal operating conditions.

Zone 22: In exceptional conditions, flammable dust clouds occur occasionally and only for a short period of time, or occasional stacking of combustible dust or the presence of a dust layer and the creation of a flammable mixture of air and dust but located in Zone 21. If it cannot be guaranteed that the flammable dust regulations or dust layer will be excluded, it should be divided into 21 areas.