轮机英语（二三管轮）Lesson 20 Marine Compressors.ppt

Unit2AuxiliaryMachineryLesson20MarineCompressorsNewWordsandExpressionsextensively[?k?stens?vli]a.广阔地screw[skru?]n.螺丝钉reciprocate[r??s?pr?ke?t]v.往复运动knob[n?b]n.旋钮manipulate[m??n?pjule?t]v.操作contrary[k?ntr?r?]a.相反的unload[?n?l??d]v卸载moisture[?m??st??(r)]n.水分NewWordsandExpressionschamber[?t?e?mb?(r)]n.腔intermittently[?nt??m?t?ntli]ad.间歇地fluctuation[fl?kt?u?e??n]n.波动onerous[??n?r?s]a.繁重的Anaircompressorisaveryusefulmachineandisnotonlyusedextensivelyinindustryonlandbutonalltypesofshipsaswell.Onashipanaircompressorisusedtocompressairandstoreitintanksforvarioususes.Theseusescouldrangefromsimpleprocessessuchascleaninganddryingoffilterstotaskssuchasstartingtheauxiliaryenginesandthemainenginesoftheship.AirCompressorproducespressurizedairbydecreasingthevolumeofairandinturnincreasingitspressure(seeFig.20-1)(空气压缩机通过减少空气的体积，进而增加空气的压力来产生压缩空气).Differenttypesofaircompressorsareusedaccordingtotheusage.WorkingPrincipleofAirCompressorWorkingPrincipleofAirCompressorFig.20-1WorkingPrincipleofAirCompressorTherearemainlyfourtypesofcompressors:centrifugalcompressor;rotaryvanecompressor;rotaryscrewcompressor;reciprocatingaircompressor.However,onshipreciprocatingaircompressoriswidelyused.Inanaircompressor,therearetwomajorparts-acompressingsystemandapowersource.Thecompressingmechanismcanbeapiston,rotatingimpeller,orvanedependinguponwhichtypeofcompressoryouarereferringto.Asforthepower,itissuppliedbyanelectricmotororotherenergysources.Thecompressingmechanism,asthenamesuggests,helpsincompressingatmosphericairbyusingenergyfromthepowersource(顾名思义，压缩机械利用来自能源（电源）的能量压缩大气中的空气).TypesofAirCompressorsThebasicworkingprincipleofanaircompressoristocompressatmosphericair,whichisthenusedasperthere