Evap。ratめnrate・fbinary・rganics・1ventmixtureswasmeasuredat298Kandc・mparedwiththatestimatedfr・m the　Knudsell　type　equatioll　incorporating　Raoult’s　law、The　solvent　mixtures　used　were　benzene・toluene　system　as　an　ideaI solution，and　as　a　nonideal　solution　wefe　hexane’benzene，benzene・敏hanol，and　hexane・ethanol　systems　with　activity c〔）efficient＄1arger　thall　mity　and　trichloromethane－benzene　and　acetone－trichlommethane　systems　with　those　less　than unity．The　evaporation　rate　of　the　mixtures　observed　agreed　well　with　that　estimated　from　the　known　evaporation　rates of　the　pure　solvents，The　knowledge　of　the　mean　evaporation　coefficient　depending　on　the　gas　phase　turbulence　enabled the　easier　estimation　of　the　evaporation　rate　of　the　mixtures.

As one method of prctection measures for released combustible gases, we did an experirnent on quick dispersion of released propane gas, using watcr spray barrier. The water spray barrier was made from water jetted from 8 flat spray nozzles mounted at 30' and 28 flat ~pray nozzies at 120', which were fitted on four steel pipes of aperture 80 A, The pipes were fonTring a square of 3 5m length, and 6 meters above the ground in calm atm(,sphere. Water pump jetted water at 1200 !/min under maximum pre~sure of 5kg/cm'G. The test gas was effused from an areal source of Imxlm at 2000 I/min and flowed on the ground. The wind velosity was O-3ml~ec (mean) , We found that this water spray barrier was effective in dispersing released gases quickly, arfd especially dispersing released gase~ of high density that were flowing on the ground in low wind velosity It was also effective in eliminating standing released gases surrounded by four dikes.

The Operability Study, which is a methodolagy to identify hazards produced in continuous prOcesses, is expanded for the application to batch prOcesses The gerleral characteristics of batch processes are as follow8 : l Plant conditions cllange periodically 2 Deviations occur not only in pipelines connected to ve~sel~ for cOntinuous processes, but also in auxiliaries like heating l]nits fc}r batch process The operation c(msists of these three proces8es "charge", "re~ction" and "discharge". The methodOlogy is based on input-Outptlt relationships amang main and auxiliary plant items. Input include~ three kinds of variables that are initi~l conditions af state variables, m~nipulating variables and operating time. An operability study is demonstrated with a polyvin}'1 acetate plant using the developed methodalogy.