輻射松板材高溫及降溫干燥機(jī)理及工藝的研究.pdf

1、Y905108分類(lèi)號(hào)密級(jí)TS652CK學(xué)位代碼308學(xué)校代碼10298學(xué)號(hào)030148南京林業(yè)大學(xué)論文題目：輻射松板材高溫及降溫干燥機(jī)理及工藝的研究作者：劉彬?qū)I(yè)：禾材科學(xué)與技術(shù)研究方向：木材干燥指導(dǎo)教師：倆煉百教授二oo六年六月Studyonmechanismandtechnologyofhigh—temperatureandloweringtemperaturedryingofPinusradiataboardAbstractMoi

2、sturemovementduringwooddryingprocessisthefundamentalresearchofwooddrying，therateofmoisturemovementdirectlyaffectsthedryingrateandthelawofdryingstresschanginginwoodTheobjectofthispaperwasPinusradiataboardThedryinglawandth

3、etransversemoisturediffusioncoefficientofPinusradiataboardintheconditionofconstantli曲temperatureandinthatofconstanthigh—temperatureinearlystageandloweringtemperatureinlatestagewerestudiedItwasrealizedtodryPinusradiataboa

4、rdintheconditionofconstanthightemperatureinearlystageandloweringtemperatureinlatestagebytakingtempemtureofthecorelayerduringhigh—tempeLaturedryingascontrollingparameterandchoosetheappropriatemoisturecontentofstartingtolo

5、wertemperatureInthispaperthetheoreticalbasisWasprovidedforsolvingthepracticalprobleminhightemperaturedryingofPinusradiataboardandtheprimarilytheoreticalexplorationwasmadeforunsteady—statenonisothermaldiffusionofmoistured

6、uringwooddryingInthispapertherelationbetweentemperatureandmoisturecontentofthecorelayerwasobtainedaccordingtothechangingrulesoftemperatureandmoisturecontentofthecorelayerandtheaveragemoisturecontentBythisrelation，tempera

7、tureofthecorelayerwastakenascontrollingparameterandtheappropriatemoisturecontentofthecorelayerwhentemperaturestartedtodeclinewaschosenBytheproperrateofloweringtemperature，moisturecontentinthicknessWasmoreevenbytheendoflo

8、weringtemperaturethanthatafterconstanthightemperaturedrying，thedryingtimewascutobviouslyThecourseofloweringtemperaturebeforeconditioningWasnotrequiredinloweringtemperaturedryinginlatestageSOtimeWassaved，timeofconditionin

9、gwasshorterandthedryingqualitywasbetterthanthoseinconstanthigh—temperaturedryingInthispapegitWasobtainedforthetransversediffusioncoefficientofP加珊radiataboardintheconditionsofallconstanthightemperaturesandinthatoflowering

10、temperatureinlatestageIntheconditionofconstanthigh—temperaturesthemoisturediffusioncoefficientofPinusradiataboarddecreasedwiththeincreaseofmoisturecontentwhenitWasabovefibersaturationpointanddecreasedwiththedecreaseofmoi

11、sturecontentwhenitwasbelowfibersaturationpointThemoisturediffusioncoefficientofPinusradiataboardinradialdirectionwaslargerthanthatintangentialdirectionThetransversediffusiontoefficientincreasedastemperatureelevatedifther