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前言-1-目录第一章设计方案的确定1.1操作压力·············································71.2进料状态············································71.3加热方式·············································71.4冷却剂与出口温度·····································81.5流程示意图···········································8第二章设计计算2.1精馏塔的物料衡算·····································92.1.1原料液及塔顶，塔底产品的摩尔分率···················92.1.2原料液及塔顶，塔底产品的平均摩尔质量···············92.1.3塔顶产品产量,塔釜液量及加热蒸气汽量的计算···········92.2塔板数的确定········································102.2.1操作温度计算及理论板层数TN的求取··················102.2.1.1有手册查的丙酮—水物系的气液平衡数据：·················10前言-2-2.2.1.2操作回流比和理论板数的确定··························112.2.1.3精馏段和提留段操作线方程的确定·······················112.2.2实际板层数的求取································122.2.2.1全塔效率TE······································132.2.2.2实际塔板数pN····································142.3精馏塔的工艺条件及有关物性数据的计算·············142.3.1精馏段与提馏段体积流量··························142.3.1.1精馏段·········································142.3.1.2提馏段·········································162.4精馏塔的塔体工艺尺寸计算·························172.4.1塔径的计算·····································172.4.1.1精馏段的塔径·····································172.4.1.2提馏段的塔径·····································182.5塔板主要工艺尺寸的计算··························192.5.1溢流装置计算···································19前言-3-2.5.1.1堰长Wl··········································192.5.1.2溢流堰高度·······································192.5.1.3弓形降液管宽度dW和降液管的面积fA·····················212.5.1.4降液管的底隙高度oh·································222.5.2塔板布置·······································222.5.2.1塔板的分布·······································222.5.2.2边缘区宽度CW与安定区宽度SW·························232.5.2.3开孔区面积aA计算··································232.5.2.4筛孔计算及其排列··································242.6筛板的流体力学验算·······························242.6.1塔板压降·······································242.6.1.1干板阻力Ch计算····································242.6.1.2气体通过液层的阻力lh计算····························252.6.1.3液体表面张力的阻力h计算····························262.6.2液面落差·······································262.6.3液沫夹带·······································26前言-4-2.6.4漏液············································272.6.5液泛············································282.7塔板负荷性能图····································292.7.1液沫夹带线······································292.7.1.1精馏段液沫夹带线··································292.7.1.2提馏段液沫夹带线··································292.7.2液泛线··········································302.7.2.1精馏段液泛线······································302.7.2.2提馏段液泛线······································302.7.3液相负荷上限线··································312.7.4漏液线（气相负荷下限线）··························312.7.4.1精馏段漏液线·····································312.7.4.2提馏段漏液线·····································322.7.5液相负荷下限线··································322.8附录-筛板塔设计计算结果列表······················34前言-5-第三章附属设备的选型和计算3.1塔附件设计··········································363.1.1进料管管径Fd·····································363.1.2塔顶蒸气出口管的直径Vd····························363.1.3回流管管径Rd·····································363.1.4塔底出料液管径Wd··································373.2筒体与封头··········································373.2.1筒体：壁厚选6mm，所用材质为碳钢。······················373.2.2封头·············································373.2.3裙座·············································373.2.4塔顶空间高度·····································383.2.5进料段空间高度···································383.3附属设备设计······································383.3.1塔顶冷凝器的选择································383.3.2塔顶冷凝水管····································40前言-6-3.3.3冷凝水泵的选择····································413.3.4预热器的选择·····································41参考文献··············································42第二章设计计算-7-第一章设计方案的确定本设计任务为分离丙酮—水混合液。对于二元混合物的分离，应采用连续精馏流程。设计中采用泡点进料，将原料液通过预热器加热至泡点后送入精馏塔内。塔顶上升蒸汽采用全凝器冷凝，冷凝液在泡点下一部分回流至塔内，其余部分经产品冷却器冷却后送至储罐。该物系为非理想物系，最小回流比通过作相平衡图切线求取,操作回流比由与塔费用的关系决定。塔釜采用直接蒸汽加热，塔底产品经冷却后送至储罐。1.1操作压力蒸馏操作通常可在常压、加压和减压下进行。确定操作压力时，必须根据所处理物料的性质，兼顾技术上的可行性和经济上的合理性进行考虑。例如，采用减压操作有利于分离相对挥发度较大组分及热敏性的物料，但压力降低将导致塔径增加，同时还需要使用抽真空的设备。对于沸点低、在常压下为气态的物料，则应在加压下进行蒸馏。当物性无特殊要求时，一般是在稍高于大气压下操作。但在塔径相同的情况下，适当地提高操作压力可以提高塔的处理能力。1.2进料状态进料状态与塔板数、塔径、回流量及塔的热负荷都有密切的联系。在实际的生产中进料状态有多种，但一般都将料液预热到泡点或接近泡点才送入塔中，这主要是由于此时塔的操作比较容易控制，不致受季节气温的影响。此外，在泡点进料时，精馏段与提馏段的塔径相同，为设计和制造上提供了方便，因此,此设计采用泡点进料。1.3加热方式因分离物系中本身含有水分，蒸馏釜的加热方式采用直接蒸汽加热，直接蒸汽加热的优点是：可以利用压力较低的蒸汽加热；在釜内只须安装鼓泡管，不须安置第二章设计计算-8-庞大的传热面。这样，可节省一些操作费用和设备费用。然而，直接蒸汽加热，由于蒸汽的不断通入，对塔底溶液起了稀释作用，在塔底易挥发物损失量相同的情况下，塔底残液中易挥发组分的浓度应较低，因而塔板数稍有增加。采用直接蒸汽加热时，加热蒸汽的压力要高于釜中的压力，以便克服蒸汽喷出小孔的阻力及釜中液柱静压力。1.4冷却剂与出口温度用常温水作冷却剂，最经济，水的入口温度由气温决定，出口温度设计时确定。冷却水出口温度取得高些，冷却剂的消耗可以减少，但温度差较小，传热面积将增加。冷却水出口温度的选择由当地水资源确定，但一般不宜超过50℃，否则溶于水中的无机盐将析出，生成水垢附着在换热器的表面而影响传热。1.5流程示意图图1第二章设计计算-9-第二章设计计算2.1精馏塔的物料衡算2.1.1原料液及塔顶，塔底产品的摩尔分率丙酮的摩尔质量AM=58kg/kmol；水的摩尔质量BM=18kg/kmol则(摩尔分率，下同)2.1.2原料液及塔顶，塔底产品的平均摩尔质量=40.15=56.492.1.3塔顶产品产量,塔釜液量及加热蒸气汽量的计算以年工作日为300天,每天开车24小时计,进料量为:F==8333.3由全塔物料恒算方程可得:第二章设计计算-10-2.2塔板数的确定2.2.1操作温度计算及理论板层数TN的求取采用图解法求理论板层数。2.2.1.1有手册查的丙酮—水物系的气液