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目 录

1、引 言 ····························································································· 2

1．1塔设备的类型 ············································································ 2 1．2板式塔的类型与选择 ··································································· 2 2、工艺流程说明 ···················································································· 6

2.1工艺流程图 ················································································· 6 2.2工艺流程图说明 ··········································································· 6 3、 塔的工艺计算 ·················································································· 7

3.1 物料恒算 ··················································································· 7

3.1.1 原料液及塔顶，塔底产品的摩尔分率 ······································· 7 3.1.2 平均分子量 ········································································ 7 3.1.3 物料恒算 ··········································································· 8 3.2理论板数的确定 ··········································································· 8

3.2.1 理论板数的确定 ·································································· 8 3.2.2实际板数的确定 ·································································· 10 3.3 塔径及塔板有效高度的确定 ·························································· 10

3.3.1操作参数及物性参数的确定··················································· 10 3.3.2 塔的工艺尺寸确定 ······························································ 13

4、 塔板主要工艺尺寸计算 ····································································· 14

4.1 塔板结构尺寸的确定 ··································································· 14

4.1.1 溢流装置的计算 ······························································· 14 4.1.2塔板布置 ··········································································· 15 4.2塔板流体力学验算 ······································································· 16

4.2.1气体通过塔板压降 ······························································· 16 4.2.2液泛 ················································································· 17 4.2.3雾沫夹带 ··········································································· 18 4.2.4 漏液 ················································································ 18 4.3 塔板负荷性能图 ········································································· 19

4.3.1雾末夹带线 ········································································ 19 4.3.2液泛线 ·············································································· 19 4.3.3液相负荷上限线 ·································································· 20 4.3.4漏液线 ·············································································· 20 4.3.5液相负荷下限线 ·································································· 20 4.4设计结果一览表 ·········································································· 21 5、结束语 ···························································································· 23 6、符号说明 ························································································· 23 7、参考文献 ························································································· 25 8、附图 ······························································································· 25

化工原理课程设计

1、引 言

1．1塔设备的类型

塔设备是化工、石油等工业中广泛使用的重要生产设备。塔设备的基本功能在

于提供气、液两相以充分接触的机会，使质、热两种传递过程能够迅速有效地进行；还要能使接触之后的气、液两相及时分开，互不夹带。因此，蒸馏和吸收操作可在同样的设备中进行。

根据塔内气液接触部件的结构型式，塔设备可分为板式塔与填料塔两大类。 板式塔内沿塔高装有若干层塔板(或称塔盘)，液体靠重力作用由顶部逐板流向塔底，并在各块板面上形成流动的液层；气体则靠压强差推动，由塔底向上依次穿过各塔板上的液层而流向塔顶。气、液两相在塔内进行逐级接触，两相的组成沿塔高呈阶梯式变化。

填料塔内装有各种形式的固体填充物，即填料。液相由塔顶喷淋装置分布于填料层上，靠重力作用沿填料表面流下；气相则在压强差推动下穿过填料的间隙，由塔的一端流向另一端。气、液在填料的润湿表面上进行接触，其组成沿塔高连续地变化。

目前在工业生产中，当处理量大时多采用板式塔，而当处理量较小时多采用填料塔。蒸馏操作的规模往往较大，所需塔径常达一米以上，故采用板式塔较多；吸收操作的规模一般较小，故采用填料塔较多。

1．2板式塔的类型与选择

板式塔为逐级接触式气液传质设备。在一个圆筒形的壳体内装有若干层按一定间距放置的水平塔板，塔板上开有很多筛孔，每层塔板靠塔壁处设有降液管。气液两相在塔板内进行逐级接触，两相的组成沿塔高呈阶梯式变化。板式塔的空塔气速很高，因而生产能力较大，塔板效率稳定，造价低，检修、清理方便。

按照塔内气液流动的方式，可将塔板分为错流塔板与逆流塔板两类。

错流塔板：塔内气液两相成错流流动，即流体横向流过塔板，而气体垂直穿过液层，但对整个塔来说，两相基本上成逆流流动。错流塔板降液管的设置方式及堰高可以

2

化工原理课程设计

控制板上液体流径与液层厚度，以期获得较高的效率。但是降液管占去一部分塔板面积，影响塔的生产能力；而且，流体横过塔板时要克服各种阻力，因而使板上液层出现位差，此位差称之为液面落差。液面落差大时，能引起板上气体分布不均，降低分离效率。错流塔板广泛用于蒸馏、吸收等传质操作中。

逆流塔板亦称穿流板，板间不设降液管，气液两相同时由板上孔道逆向穿流而过。栅板、淋降筛板等都属于逆流塔板。这种塔板结构虽简单，板面利用率也高，但需要较高的气速才能维持板上液层，操作范围较小，分离效率也低，工业上应用较少。

错流塔板又可分为一下几种： 一、泡罩塔

塔板上设有许多供蒸气通过的升气管，其上覆以钟形泡罩，升气管与泡罩之间形成环形通道。泡罩周边开有很多称为齿缝的长孔，齿缝全部浸在板上液体中形成液封。操作时，气体沿升气管上升，经升气管与泡罩间的环隙，通过齿缝被分散成许多细小的气泡，气泡穿过液层使之成为泡沫层，以加大两相间的接触面积。流体由上层塔板降液管流到下层塔板的一侧，横过板上的泡罩后，开始分离所夹带的气泡，再越过溢流堰进入另一侧降液管，在管中气、液进一步分离，分离出的蒸气返回塔板上方究竟，流体流到下层塔板。一般小塔采用圆形降液管，大塔采用弓形降液管。泡罩塔已有一百多年历史，但由于结构复杂、生产能力较低、压强降等特点，已较少采用，然而因它有操作稳定、技术比较成熟、对脏物料不敏感等优点，故目前仍有采用。如图。

图1-1泡罩式塔板

二、筛板塔

3