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(jī)械火花靜電（刷形放電）電火花Howdoesanelectrostaticdischargeoccur?

靜電是如何產(chǎn)生的？Ignition引燃Ignition引燃ChargeSeparation電荷分離ChargeAccumulationPlantunits電荷積聚于生產(chǎn)設(shè)備上ChargeAccumulationProducts電荷積聚于產(chǎn)品上ChargeDissipation電荷消散ChargeDissipation電荷消散Discharge放電Discharge放電Examples:ChargeSeparation電荷分離的范例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TypesofElectrostaticDischarges靜電釋放的形式Sparkdischarge火花放電

Brushdischarge刷形放電PropagatingBrushDischarge傳播形刷形放電ConicalPileDischarge錐形放電

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雷電IgnitionSources著火源IncentivityforBrush

discharge刷形放電MIE<3mJConicalpiledischarge錐形放電MIE<1J(D

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3m)Sparkdischarge火花放電MIE<1JPropagatingBrushdischarge傳播形刷形放電MIE<10JTypesofElectrostaticDischarges靜電放電的類型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(qiáng)度時）BrushDischarge刷形放電Separationofchargesandelectrostaticcharge分離過程和荷電PartialDischarge局部有限的電荷消散Gradeofdischarge(nonconductiveobject)

放電的等級（非導(dǎo)電體）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(shí)踐中刷形放電的范例Brushdischargesoccurwhenaconductive,groundedandcurvedobject(electrodewithradiusbetween5-50mm)isexposedtoahighelectricfield.當(dāng)曲率半徑為5-50mm內(nèi)的的接地、導(dǎo)電的物體（電極）受強(qiáng)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Dischargeofasolidmaterialoutofanon-conductiveplasticbag

放空塑料袋（非導(dǎo)電體）中的固體物料BrushDischarge–ExamplesI刷形放電范例ILoweringofaconductivegroundedsamplingcanorlevelprobeintoavesselwithanon-conductiveliquid(e.g.Toluene)將接地的導(dǎo)電的取樣器下插取樣或?qū)⒁何挥嬌烊氲椒菍?dǎo)電液體中去（如甲苯）Approachofaconductiveelectrodesuchasatoolorfingertiptoahighlychargedinsulatedsurface(e.g.FIBC)導(dǎo)電電極如工具或人的指尖接近高荷電的絕緣體表面（如傳送液體或粉塵的塑料管塑料袋傳送帶等）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Transfer-pipe

withisolatingcoating在具有內(nèi)層絕緣涂料的管道中Dustcollectorwithisolatingcoating在具有內(nèi)層絕緣涂料的旋風(fēng)分離器中Example:

Propagatingbrushdischarges

傳播形刷形放電范例PropagatingBrushDischargesinPractice生產(chǎn)實(shí)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(qiáng)度的材料，擊穿電壓小于４ＫＶ的絕緣層ExamplesofConicalPileDischargesinPractice生產(chǎn)實(shí)踐中錐形放電的范例Fillingoflargesilosandcontainerswithhighlynon-conductivegranules(insulatingbulkmaterials)e.g.,pneumaticfillingofpolymers.

Isolateddischarges atabulkedmaterial surface.將高絕緣的散裝物料（絕緣的散裝物料），加入到大料倉和容器,比如如氣動方式將聚合體加到孤立的的散裝料表面時曾觀察到在散裝物料表面發(fā)生的絕緣放電Avoidanceofhighdangerouselectrostaticcharges

生產(chǎn)實(shí)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Groundmetalflanges