Page 448 - konishipaper

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Fig.3.Theevaporationcurvesforgasolinevaporm目 suredbytheRI-415gas detectorandtheReidmethod，specifiedinJI51<258，whichisequivalentto150 307andA5TM4953.
Inthisaccident，theexplosionpropagatesbetweenlinkedcompart- ments，aphenomenoncaled“pressurepiling"occurs，character- ized by an increase in the initial pressure and atmospheric densityinthesecondcompartment.W eexplainanddiscusthe boatexplosionprocessesbyseparatingthreediferentstagesas: (1) leakage ofgasoline vapor from fuel tank，(2) difusion and accumulation ofgasoline vapor in each compartment，and (3) ignitionofgasolinevaporandflamepropagationbetweenlinked compartments.Finaly，inordertoconfirmthepresumedmecha-
Fig.4.TheconversioncurvefortheRI-415gasdetector(forトbutane)togasoline vaporwiththeReidmethod.Forourconvenience，twoconversioncurvesareshown infigure，oneplotedonavolumetricpercentage(vol.%)s日 leandtheotherona percentageofleanflamablelimit(LFI.%)scale目
nismoftheaccident，areproducibilitytestwascariedoutwitha mock-upboatunderconditionssimilartotheactualacciden.t
4.1.Lealwgeofgasolinevaporfromfueltank
Anesentialfirststepinelucidatingtheexplosionmechanismis detectionofgasolineleakage.Leakageofgasolinevaporfromthe fueltankwasvisualizedbytheschlierenmethod.Theoriginalfuel
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Fig.2.Photographsofthemock-upboat:(a)thebodyofthemocl←uphasalengthof224cm，awidthof159cmandaheightof50cm，(b)thecompartmentsAandBwere conectedbyanopeningthathadalreadybenmadebyaboatcompanybeforetheacident，(c)thecompartmentsAandCwereconectedbyholes，whichweremadebythe boatowner，(d)and(e)similarly，aholeconectedcompartmentsBandC，andcompartmentsCand0，and(f)theconcentrationofgasolinevaporintheboatwasmeasured byaportablehydrocarbongasdetector(RII<ENI<EII<IRI-415).
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