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ID:37664481
大小:1.51 MB
页数:49页
时间:2019-05-28
《真空冷冻干燥技术的设备与工艺》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、真空冷冻干燥技术的工艺和设备摘要真空冷冻干燥技术是将含水物料在低温状态下冻结,然后在真空条件下,使冰直接升华成水蒸气并排掉脱水物料中的水分使物料干燥的--I'3高新技术。它是随制冷、真空、生物、电子等技术的发展而迅速兴起的一门多学科综合应用技术。随着冻干食品的迅速发展与应用,国内冻干食品的生产厂家也越来越多,如何运用冻干设备生产出合格的产品对生产厂家来讲都已熟知。但如何将冻干机理、冻干工艺的研究成果运用到实际的生产过程中,使整个冻干工艺达到最优值,降低成本,提高生产率,是急待解决的问题。因为真空冷冻干燥产品可以最大限度的保持新鲜物料的原有色、香、味、形和营养成分。本文通过对玫瑰花的真空冷冻
2、干燥实验的分析,对影响真空冻干的过程参数进行了试验研究。试验表明:隔板温度、干燥室真空度是很重要的两个参数;冻结速率对总冻干时间没影响。在试验测试的基础上,讨论了过程参数隔板温度、干燥室真空度的影响,目的在于减少冻干时间和降低能耗。得出最优化参数是:温度为55"C,压强为39pa,较优工艺参数的验证结果表明优化结果符合实际情况。最后通过对小型的真空冷冻干燥机的设计,探索了食品冻干设备的设计理论。关键词:真空冷冻干燥过程参数工艺冻干设各Processingandequipmentofvacuum-freezingdryingABSTRACTVacuum—freezinganddryingte
3、chniqueisadevelopedandnewtechnique,bywhichthematerialofcontainingwaterisfrozeatlow-temperaturestate,thentheicesublimesandturnsvapordirectly,waterislostwhenthevaporexhaustsSOthematerialn蚰sdry.nlistechniquespringsuprapidlyalong、vitllthedevelopmentofrefrigeration,vacuuITI,biology,electronicsandtheref
4、oreitbelongstoamulti—subjectsyntheticallyutilizingtechnology.Alongwiththerapiddevelopmentandapplicationoffreezinganddryingfood,themanufacturersbecomemoreandmore.AlthoughhoWtoproduceeligibleproductsbyusingthefreezinganddryingequiFlmenthasbeenfamiliartothethem.howtoapplythefreezinganddryingprinciple
5、andresearchproductionsaboutthetechnicstotheproductionprocessinpracticeforcontrollingthefreezinganddryingequipment,optimizingthetechnics,shorteningthefreezinganddryingtime,improvingtheproductivityandreducingthecostarenotverywell--informedformanydomesticmanufacturers.BecausetheproductofVacuum·freezi
6、nganddryingmaykeeptheintrinsticcolor,scent,flavottr,shapeandthenutritionbythegreatestextent.Accordingtotheanalysisofvacuum-dryinganddryingonrosesinthispaper,theeffectsofoperationontheheatandmasstransferduringvacuumfreezedryingarestudiedintheexperiment.Theresultsindicatethatradianttemperatureandpre
7、ssureofdryingchamberarethemosttwosignificantfactors.thereishardlyanyrelationshipbetweenfreezingrateangdryingtime.Onthebasisoftestresults,theeffectsofoperationparameterssuchasradianttemperatureandpressureofdryingc
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