靜電學(xué)的基本原理課件

StaticElectricity

-BasicPrinciples–

靜電學(xué)的基本原理HazardTriangle火三角Fuel可燃物O2(air)助燃物氧氣（空氣）IgnitionSource引燃源ExamplesofEffectiveIgnitionSources引燃源范例火，火焰，陰燃物質(zhì)熱表面靜電（火花放電）機械火花靜電（刷形放電）電火花Examples:ChargeSeparation電荷分離的范例ConductivepartsofequipmentelectricallyisolatedagainstGround設(shè)備的導(dǎo)電部分與地面完全隔離Examples:ChargeAccumulationI

電荷積聚的范例AccumulationofchargesOnelectricallynon-conductivesurfaces電荷積聚在與地面絕緣的導(dǎo)電物體的表面Examples:ChargeAccumulationII電荷聚集的范例SafetyDataneededforariskassessment

風(fēng)險分析的安全數(shù)據(jù)MinimumIgnitionEnergy;(MIE)最低引燃能量ParticleSize(Powder)粒徑（粉塵）Conductivityoftheproduct物料的導(dǎo)電性Amountofproductandflowspeed物料量和流速Conductivityofthepackagingmaterial包裝材料的導(dǎo)電性Lighting

雷電Sparkdischarge火花放電Separationofchargesandelectrostaticcharge分離過程和荷電Totaldischarge電荷完全消散Gradeofdischarge(conductiveobject)

放電等級（兩個導(dǎo)電物體距離小于擊穿強度時）Sparkdischarge火花放電personinsulatedfromgroundbyshoes人由于穿著絕緣鞋而與地面絕緣pipeelbowisolatedbyseals管道彎頭由于密封材料而絕緣ChargedObject放電體CapacityC電容CPotential電位EnergyW能量[pf][kV][mJ]Flange法蘭10100,5Smallcontainer50liter容器50升50-10082-3Metaldrum200-500liter金屬桶50-3002010–60Person人100-200127–15Sparkdischarges–Energy

火花放電-能量典型值A(chǔ)voidanceofSparkDischarges避免火花放電groundingallconductivepartsandproducts(shoes/pipeelbow)所有導(dǎo)電部分及物料（鞋/管道彎道）接地AvoidanceofSparkDischarges避免火花放電ExamplesofBrushDischargesinPractice

生產(chǎn)實踐中刷形放電的范例Brushdischargesoccurwhenaconductive,groundedandcurvedobject(electrodewithradiusbetween5-50mm)isexposedtoahighelectricfield.當曲率半徑為5-50mm內(nèi)的的接地、導(dǎo)電的物體（電極）受強電場作用時，就會產(chǎn)生刷形放電throughchargedbulkmaterial通過荷電的散裝物料throughchargeddustcloud通過荷電的粉塵云BrushDischarge–Examplescontd.刷形放電范例續(xù)Removalofanon-conductiveplasticfoil移開絕緣的塑料膜AvoidanceofBrushDischarges避免刷形放電useofconductive,groundedcontainers(noplasticbags,noplasticcontainers)通過使用導(dǎo)電的接地的包裝容器（非塑料袋，非塑料容器）以避免刷形放電PropagatingBrushDischargesinPractice生產(chǎn)實踐中傳播形刷形放電的范例inpipelinewithinsulatinginnercoating在具有內(nèi)層絕緣涂料的管道中industseparatorwithinsulatinginnercoating在具有內(nèi)層絕緣涂料的旋風(fēng)分離器中onhighspeed,insulatingconveyorbelt在絕緣的輸送帶上AvoidanceofPropagatingBrushDischarges如何避免傳播形刷形放電groundingofallconductivepartsandnoinsulatinginnercoating.所有導(dǎo)電部分接地，內(nèi)層無絕緣涂層groundingofallconductivepartsanduseofaninnercoatingwith<4kVbreakdownvoltage.所有導(dǎo)電部分接地，內(nèi)層涂料的擊穿電壓小于４ＫＶnomaterialofhighdielectricstrength,nobreakdownvoltage>4kV.采用低介電強度的材料，擊穿電壓小于４ＫＶ的絕緣層Avoidanceofhighdangerouselectrostaticcharges

生產(chǎn)實踐中避免高電荷范例高流速抗靜電添加劑非導(dǎo)電低流速導(dǎo)電非導(dǎo)電高流速Handlingofflammableliquids:

易燃液體操作AvoidanceofincendivedischargesIExclusiveusageofConductiveandGroundequipment只可使用導(dǎo)電的容器并接地AvoidanceofincendivedischargesIIHandlingofflammabledusts:易燃粉塵的操作規(guī)程Groundallconductiveequipment;smallplastic-container(i.e.bags)arepermittedaslongastherearenoflammableGasesnorflammablevapourspresent.將所用的導(dǎo)電部分接地，在無易燃液體氣體和蒸氣存在時，可容許使用小塑料容器（如包裝袋Examp