课后答案网,用心为你服务! 大学答案---中学答案---考研答案---考试答案 最全最多的课后习题参考答案,尽在课后答案网()!Khdaw团队一直秉承用心为大家服务的宗旨,以关注学生的学习生活为出发点,旨在为广大学生朋友的自主学习提供一个分享和交流的平台。 爱校园()课后答案网()淘答案() 1目录第一章流体流动与输送设备·····················································(2)第二章非均相物系分离·························································(26)第三章传热···································································(31)第四章蒸发···································································(45)第五章吸收····································································(49)第六章蒸馏···································································(69)第七章干燥···································································(83)2第一章流体流动与输送设备1.燃烧重油所得的燃烧气,经分析知其中含CO28.5%,O27.5%,N276%,H2O8%(体积%),试求此混合气体在温度500℃、压力101.3kPa时的密度。解:混合气体平均摩尔质量molkgMyMiim/1086.281808.02876.032075.044085.03∴混合密度333/455.0)500273(31.81086.28103.101mkgRTpMmm2.已知20℃下水和乙醇的密度分别为998.2kg/m3和789kg/m3,试计算50%(质量%)乙醇水溶液的密度。又知其实测值为935kg/m3,计算相对误差。解:乙醇水溶液的混合密度7895.02.9985.012211aam3/36.881mkgm相对误差:%74.5%10093536.8811%100实实mmm3.在大气压力为101.3kPa的地区,某真空蒸馏塔塔顶的真空表读数为85kPa。若在大气压力为90kPa的地区,仍使该塔塔顶在相同的绝压下操作,则此时真空表的读数应为多少?解:''真真绝pppppaakPappppaa7.73)853.101(90)(''真真4.如附图所示,密闭容器中存有密度为900kg/m3的液体。容器上方的压力表读数为42kPa,又在液面下装一压力表,表中心线在测压口以上0.55m,其读数为58kPa。试计算液面到下方测压口的距离。解:液面下测压口处压力ghpzgpp10mhgppgpghpz36.255.081.990010)4258(30101题4附图35.如附图所示,敞口容器内盛有不互溶的油和水,油层和水层的厚度分别为700mm和600mm。在容器底部开孔与玻璃管相连。已知油与水的密度分别为800kg/m3和1000kg/m3。(1)计算玻璃管内水柱的高度;(2)判断A与B、C与D点的压力是否相等。解:(1)容器底部压力ghpghghppaa水水油21mhhhhh16.16.07.010008002121水油水水油(2)BAppDCpp6.水平管道中两点间连接一U形压差计,指示液为汞。已知压差计的读数为30mm,试分别计算管内流体为(1)水;(2)压力为101.3kPa、温度为20℃的空气时压力差。解:(1)PaRgp2.370881.903.0)100013600()(0(2)空气密度333'/206.1)20273(31.81029103.101mkgRTpMPaRgp1.400281.903.0)206.113600()('0'∵空气密度较小,∴Rgp0'7.用一复式U形压差计测量水流过管路中A、B两点的压力差。指示液为汞,两U形管之间充满水,已知h1=1.2m,h2=0.4m,h4=1.4m,h3=0.25m,试计算A、B两点的压力差。解:图中1、2为等压面,即21pp11ghppA1032gRpp1031gRpghpA(1)又20365gRghpppB)(24543hhgppp)(24203hhggRghpB(2)将(2)代入(1)中:10242031)(gRhhggRghpghpBA题5附图CAh2h1DB51342643题7附图4BAABppp11024203)(ghgRhhggRgh)()(2104312RRghhhhggRR))((02181.9)100013600()25.04.14.12.1(ABpkPaPa0.2417.2410318.根据附图所示的双液体U管压差计的读数,计算设备中气体的压力,并注明是表压还是绝压。已知压差计中的两种指示液为油和水,其密度分别为920kg/m3和998kg/m3,压差计的读数R=300mm。两扩大室的内径D为60mm,U管的内径d为6mm。解:1.2为等压面,21pp111ghppgRgZRhppa2112)(gRgZRhpghpa21111)(gZRgppa112)(又2244DZdRmRDdZ003.03.0)606(22281.9920003.0)920998(81.93.0appPa6.256(表压)9.为了排出煤气管中的少量积水,用附图所示的水封装置,水由煤气管道中的垂直支管排出。已知煤气压力为10kPa(表压),试求水封管插入液面下的深度h。解:煤气表压ghpmgph02.181.91010103310.为测定贮罐中油品的贮存量,采用图1-8所示的远距离液位测量装置。已知贮罐为圆筒形,h121题8附图题9附图5其直径为1.6m,吹气管底部与贮罐底的距离为0.3m,油品的密度为850kg/m3。若测得U形压差计读数R为150mmHg,试确定贮罐中油品的贮存量,分别以体积及质量表示。解:0RhmRh4.215.0850136000罐中总高度:mZhH7.23.04.2322426.57.26.1785.04mHDVkgVm4612850426.511.绝对压力为540kPa、温度为30℃的空气,在φ108×4mm的钢管内流动,流量为1500m3/h(标准状况)。试求空气在管内的流速、质量流量和质量流速。解:标准状况下空气的密度:33000/29.127331.8029.0103.101mkgRTMpskghkgV/5375.0/193529.11500m:00s质量流量2222/47.68/2464971.0785.01935785.0G:mskgmhkgdms质量流速操作条件下密度:33/22.6)30273(31.8029.010540mkgRTPM体积流速:smGu/1122.647.6812.硫酸流经由大小管组成的串联管路,其尺寸分别为φ76×4mm和φ57×3.5mm。已知硫酸的密度为1831kg/m3,体积流量为9m3/h,试分别计算硫酸在大管和小管中的(1)质量流量;(2)平均流速;(3)质量流速。解:(1)大管:mm476hkgVmss/1647918319smdVus/69.0068.0785.03600/9785.02216smkguG211/4.1263183169.0(2)小管:mm5.357质量流量不变hkgms/164792smdVus/27.105.0785.03600/9785.02222或:smdduu/27.1)5068(69.0)(222112smkguG222/4.2325183127.113.如附图所示,用虹吸管从高位槽向反应器加料,高位槽与反应器均与大气相通,且高位槽中液面恒定。现要求料液以1m/s的流速在管内流动,设料液在管内流动时的能量损失为20J/kg(不包括出口),试确定高位槽中的液面应比虹吸管的出口高出的距离。解:以高位槽液面为1-1’面,管出口内侧为2-2’面,在1-1’~2-2’间列柏努力方程:fWupgZupgZ222221112121简化:gWuHf/)21(22m09.281.9)20121(14.用压缩空气将密闭容器(酸蛋)中的硫酸压送至敞口高位槽,如附图所示。输送量为0.1m3/min,输送管路为φ38×3mm的无缝钢管。酸蛋中的液面离压出管口的位差为10m,且在压送过程中不变。设管路的总压头损失为3.5m(不包括出口),硫酸的密度为1830kg/m3,问酸蛋中应保持多大的压力?解:以酸蛋中液面为1-1’面,管出口内侧为2-2’面,且以1-1’面为基准,在1-1’~2-2’间列柏努力方程:fhZugpZuggp222212112121简化:fhZuggp222121题13附图1题14附图7其中:smdVus/07.2032.0785.060/1.04222代入:)21(2221fhZuggp)5.31007.281.921(81.918302)(3.246表压akP15.如附图所示,某鼓风机吸入管内径为200mm,在喇叭形进口处测得U形压差计读数R=15mm(指示液为水),空气的密度为1.2kg/m3,忽略能量损失。试求管道内空气的流量。解:如图,在1-1’~2-2’间列柏努力方程:fWupgZupgZ222221112121其中:0,0)(,0,1121fWpuZZ表简化:222210up而:aoHPRgp15.147015.081.9100022smuu/66.152.115.14721222流量:hmsmudVs/1771/492.066.152.0785.043322216.甲烷在附图所示的管路中流动。管子的规格分别为φ219×6mm和φ159×4.5mm,在操作条件下甲烷的平均密度为1.43kg/m3,流量为1700m3/h。在截面1和截面2之间连接一U形压差计,指示液为水,若忽略两截面间的能量损失,问U形压差计的读数R为多少?解:在1,2截面间列柏努力方程:fWupgZuPgZ222221112121题15附图221题16附图R8简化:2222112121upup或:)(21212221uupp其中:smdVus/04.14207.0785.03600/1700785.02211smdduu/74.26)150207(04.14)(222112aPpp3.370)04.1474.26(2143.12221