




已阅读5页,还剩7页未读, 继续免费阅读
版权说明:本文档由用户提供并上传,收益归属内容提供方,若内容存在侵权,请进行举报或认领
文档简介
毕业设计(外文翻译)题目:标准筛振筛机的总体及夹紧装置的设计系别专业名称机械设计制造及其自动化班级学号学生姓名指导教师二O一一年三月COALPREPARATIONTABLE7-14.EffectofGeometryandConcentrationofFeedSolidsonthroughputfora1/6-in,diamhydrocyclonecleaning1/4-inVaryingthedistancebetweenthebottomofthevortexfinderandthehydrocycloneconebottom.Forexample,thewashedcoalashcanbereducedbydecreasingthediameterofthevortexfinder,decreasingthelengthofthevortexfinder,orincreasingthediameteroftheunderfloworifice.Increasingfeed-Solidscontentincreasesthespecificgravityofseparationand,therefore,washedcoalyieldandash,whichindicatestheimportanceofmaintainingaconstantfeed-solidscontenttopreservewashedcoalquality.Capacityisinfluencedbycyclonegeometry,i.e.,thesizesoftheoverflow,underflow,andinletopenings,andbyfeed-solidscontent.TheeffectsoftheseparametersisgiveninTable7-14.Increasinginletpressureisasimplemethodofincreasingcapacitywithoutchanginghydrocyclonegeometry,andwashedyieldandasharenotsignificantlyaffected.However,thepenaltyisincreasedpumpingcost,anddegradationofthecoal.FlowsheetsSoonafterthehydrocyclonewasdeveloped,itbecameevidentthatperformancewasinferiortonearlyallothercleaningdevices.Consequently,inanefforttoimproveperformance,threetwostagecircuits,showninFig.764,weredeveloped.Intheearliesttwo-stagecircuit,calledtwo-stagerelearnorTSR,therefusefromaprimaryhydrocycloneissimplyrelearnedinasecondaryhydrocyclone,Theoverflowsfromthetwohydrocyclonesarerecombinedasthewashedcoalproduct,andtheunderflowsfromthesecondaryhydroclonecontainsthefinalrefuse.Inmorerecentinstallations,oneoftheproductsfromthesecondaryhydrocycloneisrecirculatedtothefeedoftheprimaryhydrocyclone.Inthetwo-stageoverflowrecirculationcircuit,TSOR,theprimaryorfirst-stagehydrocycloneisadjustedtoproduceanacceptablecleancoalandthesecondaryhydrocycloneisadjustedtoproducearefuseessentiallyfreeofmisplacedcoal.Theoverflowfromthesecondaryhydrocyclone,whichcontainsthemisplacedcoalintheunderflowsoftheprimaryhydrocyclone,isreturnedtothefeedoftheprimaryhydrocycloneforreprocessing.Inthetwo-stageunderflowrecirculationcircuit,TSUR,andtheoverflowisrelearnedinthesecondaryhydrocyclone.Theunderflowfromthesecondaryhydrocloneisrecalculatedtothefeedoftheprimaryhydrocyclone.Theoverflowfromthesecondaryhydrocyclonecontainsthewashedcoal.Eachofthesecircuitshasadvantagesthatdependuponthesizeandspecificgravitycompositionsofthefeed,aswellastherequiredwashedcoalquality.TheTSORcircuitismoreeffectiveinrecoveringwashedcoalwhereastheTSURcircuitismoreeffectiveinrejectingheavyimpurity.TheTSRcircuitismosteffectivewhenthespecificgravityofseparationofthetwohydrocyclonesissimilar.Conversely,theperformanceofTSORandTSURisimprovedbydivergingthespecificgravityofseparationofthetwocyclones.Atthepresenttime,theTSORisthemostcommoncircuit.AvariationoftheTSRcircuithasbeenproposedwherebyunderflowfromtheprimarycycloneisrelearnedonaconcentratingtableratherthanasecondaryhydrocyclone.Someplantsusingjigstocleanthecoarsecoalutilizehydrocyclonestoimproveperformanceonthefinersizes.Onemethodistorelearntheunderflowofthewashedcoalscreen,commonlythe1/4-in.material,withhydrocyclones.Anothermethodistoscreentherawcoalataboutthissizeandcleantheundersizewithhydrocyclones.Hydrocycloneshavebeenusedaheadofdense-mediumcyclonestoremovesomeofthelowspecificgravitycoalandtherebyreducetheamountofmaterialsenttothedense-mediumplant.Thehydrocyclonesareadjustedtoseparateataspecificgravityofabout1.35to1.40.Theadvantageisthatthecapacityofthedense-mediumcycloneplantcanbesmaller,thusreducingcapitalandoperatingcosts.HydrocyclonePerformanceAsmentionedpreviously,thequalityofthewashedcoalandrefuseproductscanberegulatedbychangingthediametersoftheoverflowandunderfloworifices.Howeverfromaperformancestandpoint,aratioofoverflowdiametertounderflowdiameterinarangeofabout1.7to2givesthebestresults.Performanceatlowerratiosisinferior.Also,thesolidscontentinthefeedtoprimaryandsecondaryhydrocyclonesshouldrangefrom8to15%(byweight).Outsidethisrange,eitheraboveorbelow,performanceisadverselyaffected.Separationsobtainedinasinglehydrocycloneandtwo-stagecircuits(TSR)areshownbythedistributioncurvesinFig.7-65.Thesharpnessofseparationofthetwo-stagec
温馨提示
- 1. 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
- 2. 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
- 3. 本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
- 4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
- 5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
- 6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
- 7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
最新文档
- 安全事故应急预案包括哪些内容
- 关于安全生产培训的
- 可扩展空间规划-洞察及研究
- 安全生产责任制应符合相关的法律法规
- 专职安全员安全工作总结
- 安全生产标准化意义
- 系统级建模与仿真在分布式太阳能中的应用-洞察阐释
- 糖尿病大血管内皮功能障碍的新型生物标志物研究-洞察阐释
- 【正版授权】 ISO/IEC 23894:2023 FR Information technology - Artificial intelligence - Guidance on risk management
- 【永磁同步电机模型预测控制研究的国内外文献综述3100字】
- 《空压机节能技术及应用》课件
- 2025-2030年中国塑料制品行业产销需求及投资前景预测研究报告
- 2025年留置辅警面试题目及答案
- 工伤预防培训
- 呼伦贝尔农垦集团有限公司招聘考试真题2024
- 陕投集团招聘笔试真题答案下载版
- 设备管理考试题及答案
- 《教育强国建设规划纲要(2024-2035)》解读与培训
- 2023年高考真题-物理(广东卷) 含答案
- 2025年湖北荆门市交通旅游投资集团有限公司招聘笔试参考题库附带答案详解
- 无损检测员(铁路探伤工)理论试题(高级工)
评论
0/150
提交评论