《工业分析 Industrial Analysis》课件-开口杯法测定闪点（双语）

项目八：常规物理常数与性能分析任务五：闪点的测定开口杯法测定煤油闪点课程：工业分析中文Scenario8:PhysicalconstantsandperformancetestingTask5:DeterminationofflashpointOpencupmethodfordeterminingtheflashpointofkeroseneCourse:IndustrialAnalysisEglish一、基本概念闪点：在规定条件下，易燃性物质受热后所产生的油蒸汽与周围空气形成的混合气体，在遇到明火时发生瞬间着火（闪火现象）时的最低温度，称为该石油产品的闪点。燃点：能发生连续5s以上的燃烧现象的最低温度，称为燃点问题：闪点与燃点哪个高？燃点高中文一、BasicconceptsFlashpoint:Underspecifiedconditions,thelowesttemperatureatwhichthevaporgeneratedbyaflammablesubstanceheatedmixeswiththesurroundingairandignitesinstantlyuponencounteringanopenflame(flashphenomenon)iscalledtheflashpoint.Burningpoint:Thelowesttemperatureatwhichcombustioncanoccurcontinuouslyformorethan5seconds,knownastheburningpointQuestion:Whichisthehighertemperature,flashpointorburningpoint?burningpointEglish测定意义预示出现火灾和爆炸危险性程度的指标。油品的危险等级是根据闪点来划分的，闪点在45℃以下的叫易燃品，45℃以上的为可燃品。对油品而言，闪点值还可以判断其馏分轻重和质量，闪点越低，馏分越轻。与沸点的关系？中文ThesignificanceofflashpointdeterminationAnindicatorindicatingthedegreeoffireandexplosionhazard.Thehazardlevelofoilproductsisclassifiedbasedontheirflashpoint.Productswithaflashpointbelow45℃areconsideredflammable,whilethosewithaflashpointabove45℃areconsideredflammable.Foroilproducts,theflashpointvaluecanalsodeterminetheweightandqualityoftheirfractions.Thelowertheflashpoint,thelighterthefraction.Whatistherelationshipwithboilingpoint?Eglish测定闪点的方法有开口杯法和闭口杯法两种开口杯法测定的闪点要比闭口杯法高20—30℃一般情况下，高闪点的物质采用开口杯法，低闪点的物质采用闭口杯法测定

why中文Therearetwomethodsformeasuringflashpoint:opencupmethodandclosedcupmethodTheflashpointmeasuredbytheopencupmethodis20-30℃higherthanthatbytheclosedcupmethodIngeneral,substanceswithhighflashpointsaremeasuredusingtheopencupmethod,whilesubstanceswithlowflashpointsaremeasuredusingtheclosedcupmethodwhyEglish1、准备工作试样的水分大于0.1%时，必须脱水。脱水处理是在试样中加入新煅烧并冷却的食盐、硫酸钠或无水氯化钙进行。闪点低于100℃的试样脱水时不必加热；其他试样允许加热至50～80℃时用脱水剂脱水。脱水后，取试样的上层清液部分供实验使用。二、开口杯法测定煤油闪点中文1、preparation

Whenthemoisturecontentofthesampleexceeds0.1%,itmustbedehydrated.Dehydrationtreatmentinvolvesaddingnewlycalcinedandcooledsalt,sodiumsulfate,oranhydrouscalciumchloridetothesample.

Sampleswithaflashpointbelow100℃donotneedtobeheatedduringdehydration;Othersamplesareallowedtobedehydratedwithadehydratingagentwhenheatedto50-80℃.Afterdehydration,taketheupperclearliquidpartofthesampleforexperimentaluse.二、OpencupmethodfordeterminingtheflashpointofkeroseneEglish内坩埚用溶剂油洗涤后，放在点燃的煤气灯上加热，除去遗留的溶剂油。待内坩埚冷却至室温时，放入装有细纱（经过煅烧）的外坩埚中，使细纱表面距离内坩埚的口部边缘约12mm，并使内坩埚底部与外坩埚底部之间的厚度5～8mm的砂层。对闪点在300℃以上的试样进行测定时，两只坩埚底部之间的砂层厚度允许酌量减薄，但在实验时必须保持适当的升温速度。中文Afterwashingtheinnercruciblewithsolventoil,heatitonalitgaslamptoremoveanyremainingsolventoil.Whentheinnercruciblecoolstoroomtemperature,placeitintoanoutercruciblecontainingfineyarn(calcined),sothatthesurfaceofthefineyarnisabout12mmawayfromtheedgeoftheinnercrucible'smouth,andthereisasandlayerwithathicknessof5-8mmbetweenthebottomoftheinnercrucibleandtheoutercrucible.Whenmeasuringsampleswithaflashpointabove300℃,thethicknessofthesandlayerbetweenthebottomofthetwocruciblescanbeslightlyreduced,butanappropriateheatingratemustbemaintainedduringtheexperiment.Eglish煤油注入内坩埚，液面距离坩埚口部边缘为12mm（对于闪点在210℃和210℃以下的试样，液面距离坩埚口部边缘为12mm；对于闪点在210℃以上的试样，液面距离口部边缘18mm）。试样向内坩埚注入时，不应溅出，而且液面以上的坩埚壁不应沾有试样。将温度计垂直地固定在温度计夹上，并使温度计的水银球位于内坩埚中央，与坩埚底和试样液面的距离大致相等。中文

Keroseneisinjectedintotheinnercrucible,andtheliquidlevelis12mmawayfromtheedgeofthecruciblemouth(forsampleswithflashpointsbelow210℃and210℃,theliquidlevelis12mmawayfromtheedgeofthecruciblemouth;forsampleswithflashpointsabove210℃,theliquidlevelis18mmawayfromtheedgeofthecruciblemouth).Wheninjectingthesampleintotheinnercrucible,itshouldnotsplashout,andthecruciblewallabovetheliquidlevelshouldnotbecontaminatedwiththesample.Fixthethermometerverticallyonthethermometerclampandplacethemercuryballofthethermometerinthecenteroftheinnercrucible,roughlyequaltothedistancebetweenthebottomofthecrucibleandtheliquidsurfaceofthesample.Eglish2、测定打开电源开关，使试样在开始加热后能迅速达到（10±2）℃/min的升温速度。当达到预计闪点前约10℃左右，移动点火器火焰于距试样10～14mm处，并沿着内坩埚上边缘水平方向从坩埚一边移到另一边，经过时间为2～3s。试样温度每升高2℃，重复点火试验一次。中文2、Determine

Turnonthepowerswitchsothatthesamplecanquicklyreachaheatingrateof(10±2)℃/minafterstartingheating.Whenthetemperaturereachesabout10℃beforetheexpectedflashpoint,movetheigniterflameatadistanceof10-14mmfromthesampleliquidsurfaceandmovehorizontallyalongtheupperedgeoftheinnercruciblefromonesideofthecrucibletotheother,taking2-3seconds.Repeattheignitiontestforevery2℃increaseinsampletemperature.Eglish当试样表面上方最初出现蓝色火焰时，立即从温度计读出温度作为该试样的闪点，同时记录大气压力。若测定燃点，继续加热，保持（4±1）℃/min的升温速度，每升高2℃点火试验一次。当能继续燃烧5s时，立即从温度计读出并记录测定温度，即为试样的燃点。中文Whenablueflamefirstappearsabovethesurfaceofthesample,immediatelyreadthetemperaturefromthethermometerastheflashp