Dust Explosion-proofAreaRegionmustUseDust Explosion-proofElectrical，Such asDust explosion-proof distribution box，InvincibleAbilityUseFlameproof Type Or Ordinary Distribution Box，Dust Explosion-proofAreaRegioncontainingCombustible Dust、Conductive Dust And DustGasMixingOverallMineral，commonAreaRegionWithcoal washing plant、Chemical Plant、Pharmaceutical Factory、DustWorkshopEtc.。

　　Division of dust explosion-proof areas.

　　Zone 20:innormaloperationDuringExtentIn，Combustible DustContinuityOutputOn-site Or Frequently OutputOn-site，ItsquantitySatisfyWithDescribeCostCombustible Dust And AerospaceStationMixingOverallMineral And / Or May DescribeCostnonAlgorithmcontrol And very Thick的DustLayer的location And AsApplianceInternal。

Zone 21: Places where, during normal operation, dust may appear in quantities sufficient to form combustible dust-air mixtures but which are not classified as Zone 20.。This area includes: places directly adjacent to dust charging or discharging points, places where dust layers appear, and places where combustible dust-air mixtures may be produced under normal operating conditions.。

　　Zone 22: Places where, under abnormal conditions, combustible dust appears occasionally and only for a short period, or where combustible dust may occasionally accumulate or dust layers may exist and produce combustible dust-air mixtures.。If it cannot be ensured that combustible dust accumulation or dust layers are excluded, then it should be classified as Zone 21.