塔板持液量的测定与计算

本文给出了四种塔板的持液量测定数据及其计算关联式,并与文献公式进行了比较。所得公式对塔板工程计算将提供有益的帮助。     

复合塔板气液运动的实验研究

采用多路电导测试系统,在直径500mm的冷模塔内,以空气-水为试验物系,研究了开孔率20%和25%复合塔板上的气液运动规律.实验揭示了气液穿孔运动的三种状态通液、通气和阻塞,并对复合塔板的气液运动机理进行了阐述.实验考察了空塔动能因子F、喷淋密度LV和开孔率φ对通液率、通气率和阻塞率的影响,分析了筛孔真实气速与复合塔液泛点关系.结果表明F因子增大,通气率也增大,而通液率和阻塞率减小;喷淋密度增加, 通气率下降,通液率上升;开孔率较大,则通气率较小,通液率和阻塞率较大;在实验范围内(开孔率20%及25%、喷淋密度5～40m3·(m2·h)-1的情况),复合塔液泛点的筛孔真实气速在11m·s-1左右,为其它物系确定操作上限提供了依据.     

复合塔板上气液穿孔流动测试方法

开发了多路电导测试系统,用于复合塔气液穿孔流动的研究。在开孔率20％的复合塔板上,布置了86路电导探针,在多种操作状态下,详细测定了通气、通液、阻塞筛孔数所占的分率以随气液流量变化的情况。为复合塔板气液流动规律的分析和结构改进提供了新的依据。     

气液并流旋喷塔板的流体力学性能

结合新垂直筛板塔(NVST)和旋流板的特点提出了一种新型塔板——气液并流旋喷塔板，以空气水体系测试其流体力学性能。实验表明这种塔板的压降比NVST塔板减小10％20％，雾沫夹带上限比NVST塔板低，这些特性将使其比NVST塔板有较大的处理能力；而大提升量则保证了其有较高的传质效率，是一种很有应用前景的塔板。     

折流式旋转床持液量的研究

将折流式旋转床分成若干液体流动区,计算流动区内动、静圈壁上液膜及动、静圈之间液滴的运动时间,在此基础上建立折流式旋转床持液量模型. 以空气-水为物系,在直径300 mm、高51 mm的折流式旋转床中进行实验,分别测得不通和通空气时转子的持液量,用实验数据拟合出持液量模型参数. 结果表明,转子持液量随液量和气量增加而增加,随转子转速增加而减小,高转速下气量对持液量的影响明显减弱. 折流式旋转床不通气持液量为2.35%~3.68%,是普通丝网旋转填料床不通气持液量的1.32~2.06倍.     

气液并流填料塔的持液量

本文提出用静持液准数E对文献及本试验静持液数据进行关联;在受力分析基础上得到单相持液的半经验关系式,使用范围及精度均比文献值有所提高。对脉冲流区后的动持液量提出了单独的经验关联。     

气液向上或向下并流固定床动持液量测定

引　言固定床也可用作气 -液 -固三相反应器 ,其中气体和液体可并流向下或并流向上通过催化剂颗粒床层而发生化学反应 .它广泛应用于各种化工过程[1].床层中的动持液量是一个估算液体平均停留时间和液膜厚度必不可少的参数 ,也是反应器内液 -固接触效率的一个量度 ,它直接影响催化剂的润湿程度和反应器的性能 ,因此持液量常是关联固定床 (或滴流床 )反应器内传质系数和传热系数的变量之一 .随着化工工业的发展 ,往往要进行原料脱杂质处理过程 (一般是加氢过程 ) ,需要足够的催化剂床层持液量 .工业上采取催化剂颗粒小型化、异形化和脉动操作…     

高气液比复合填料板的压降与持液性能研究

为实现对低压大气量废气中的污染物进行高效的分离与富集,开发了一种高气液比复合填料板,以空气-水为实验物系,对该复合填料板的压降和持液性能进行了研究。结果表明,复合填料板的干板压降Δp与气相动能因子F的关系符合幂函数关系,在相同喷淋密度(L=30.6L·m~(-2)·h~(-1))条件下,复合填料板的动持液量较BX500填料的整体高了58～130倍。在相同L条件下F从3.2增长到6.5 m·s~(-1)·kg~(1/2)·m~(-3/2),复合填料板的湿板压降增长了162%～201%;而相同F条件下L从30增长到60L·m~(-2)·h~(-1),湿板压降增长了67%～108%。与普通填料相比,复合填料板在高气液比条件下表现出了低压降和高持液量的显著优势。     

立体传质塔板CTST板上清液层高度的研究

应用改进的连通法对主体传质塔板CTST的板上清液层高度进行了测量,结果表明立体传质塔板的板上清液层高度是不均匀的;其板上清波层高度随溢流强度和堰高的增加而增加,随板孔气速的增大先降低后又有所回升.给出了测量数据及其计算关联式,为该塔板的工程设计提供了一定的依据.     

拉西环填料塔体动持液量和面动持液量及其计算

首次提出填料塔动持液量不是均匀分布的，高径比是影响动持液量的一个重要参数。定义整个床层的平均动持液量为体动持液量；定义填料层中水平截面上微分薄层的平均动持液量为面动持液量。根据实验数据和优化计算方法，得出恒持液量区到泛点拉西环填料层体动持液量计算修正式和面动持液量计算式。     

立体传质塔板板上液相速度场的实验研究

在1 000 mm的冷模实验塔内采用热膜测速仪对立体传质塔板(CTST)的板上液相速度分布进行了实验研究。得到了CTST板上液相在平面上的速度分布特征;在液层高度方向,液相速度分布在塔板进口、出口和帽罩的底隙附近,分别具有不同的特点。考察了堰高、液体流量、板孔气速对板上液相流场的影响。测量结果表明,罩内气体的提升作用对板上液相流场影响较大,底隙附近的液体速度与进入塔板的液体速度之比随堰高和板孔气速的增大而增大,随着液体流量的增大,该比值减小到一定程度后略有回升。     

Hydrodynamics performance and tray efficiency analysis of the novel vertical spray packing tray

Column setup has been widely utilized in the petroleum and chemistry industries. However, with the fast progress of industries and the increasingly serious energy shortage, designing a new column setup with better performance and higher capacity becomes more urgent. In order to improve column's capacity and expand operating condition, a new type of column tray named novel vertical spray packing (NVSP) tray was designed and experimented. The performances of the novel tray, including pressure drop, weeping, entrainment and tray efficiency, were tested in a plexiglass column. In addition, performances of the novel tray were compared with that of the sieve tray and the Glitsch V1 valve tray. Based on the experiment data, the mathematical correlations of pressure drop, weeping and entrainment for the novel tray were established by regression analysis method. A fundamental model of dry pressure drop of the novel tray was promoted at the form of sum mode. The results indicate that the novel tray has wider operating condition and better performance.     

Study on reaction magnitude of solid reactive spray tray

用强酸型阳离子交换树脂作催化剂,以乙醇和乙酸催化反应生成乙酸乙酯为研究对象,对立体催化精馏塔板的反应量进行了系统的实验研究。考察了催化剂高度、醇酸摩尔比、流速对反应量的影响,并关联得到了反应量的经验式。基于反应量的经验公式与质量守恒定律,建立了塔板上液相中乙酸乙酯质量分数的模型,并通过对工业试验塔板上反应量的测量对模型进行了验证。     

喷雾冲击条件下液膜流动与传热模型

针对现有喷雾冷却计算模型的不足,以质量、动量、能量守恒方程为基础,建立喷雾冷却非沸腾区的液膜流动与传热方程,并采用数量级分析的方法对方程简化,最后运用数值方法对模型进行求解。给定液滴速度及液体温度,由模型计算液膜厚度、平均热通量与液体流出温度,与实验测试结果对照。结果显示,液膜厚度的计算结果与实验结果相差6%以内;平均热通量和液体离开待冷却表面的最终温度计算结果与实验结果相差10%以内,且超过60%的计算结果偏差小于5%。计算结果与实验结果的高度匹配证明该模型可较好地反映喷雾冷却过程的流动与换热。由模型可以获取不同位置处液膜厚度与温度,从而加深对喷雾冷却传热机理的理解。     

Firing characteristics of size-controlled silver-glass composite powders prepared by spray pyrolysis

Size-controlled spherical silver-glass composite powders were directly prepared by using spray pyrolysis. The mean sizes of the composite powders changed from 0.34 to 0.78 μm when the concentration of the spray solution was changed from 0.05 to 2 M. The firing characteristics of composite powders formed from the spray solutions with a glass content equal to 3 wt.% of the silver component were affected by the mean sizes of the powders. Silver-conducting films formed from large-sized composite powders had a denser structure than those formed from small-sized composite powders. Further, silver-conducting films formed from composite powders with a mean size of 0.78 μm had specific resistances of 3 and 2 μΩ cm at firing temperatures of 450 and 500 °C. However, silver-conducting films formed from composite powders with a mean size of 0.34 μm had specific resistances of 8.2 and 6.9 μΩ cm at firing temperatures of 450 and 500 °C.     

超亲水微纳复合表面低流率蒸发液膜铺展特性

薄液膜在微反应器、微接触器等微过程中都有着重要的应用,提升表面毛细性能是实现低流量下液膜铺展的有效方法.制备得到了一种具有内部互连通道的微纳复合表面,对于工质水表面抽吸系数高达16.11mm-s-0.5.对毛细抽吸过程进行了可视化观测,结果表明微纳复合表面内部互连的微米级间隙作为流体的输运通道,可以大幅降低流动阻力;并...     

立体传质塔板板上液相流场的三维数值模拟

针对立体传质塔板(CTST)操作时的特点,对1 000 mm的CTST板上液相流场进行了三维计算流体力学(CFD)数值模拟.计算得出了板上液相流场的三维分布特征;实验测量和模拟结果对比,结果吻合较好,说明文中模型有较好的准确度,可以用于CTST板上液相流场的预测.对相同条件下筛板和CTST板上的液相流场分别进行模拟,...     

Hydrodynamics and mass transfer performance analysis of flow-guided trapezoid spray packing tray

Distillation is the most common separation technology utilized in the petroleum and chemistry industries. Due to the wide usage of the distillation column, even a small improvement in performance may result in significant energy cost savings. Aiming to improve the hydrodynamics and mass transfer performance, the flow-guided trapezoid spray-packing tray (FTS-PT) was designed by combining flow-guided holes and trapezoidal caps with structured packing. And the experimental measurements of the FTS-PT, including pressure drop, clear liquid height, weeping, entrainment, and tray efficiency, were conducted in a 500 mm diameter plexiglass column with the air-water-oxygen system. Moreover, the performance of the FTS-PT was compared with that of new vertical sieve tray (New VST) and F1 valve tray. The results show that FTS-PT has a significant advantage in pressure drop, entrainment, and capacity. Furthermore, the calculation model of the pressure drop was derived and used for the FTS-PT with a relative deviation of less than 5%.     

Flow regimes and pressure drop of a composite tridimensional rotational flow sieve tray under concurrent gas-liquid flow

A composite tridimensional rotational flow sieve tray (CTRST) is proposed. The flow patterns of CTRST were visually categorized, combined with the standard deviation of the pressure difference. In the TRST area of the internal packing-type tray, the membrane-drip column and foam-embolic flow is present, while bubbly and milk froth-ribbon flow is present in the packing area of the external packing-type tray. The effect of the tray structure parameters on the pressure drop under co-current flow was investigated. The dry and wet pressure drop is within 160 and 900 Pa, respectively. Under the same structural parameters, the pressure drop of the internal packing-type tray was higher than that of the external packing-type tray. The flow characteristics of the standard tray under the countercurrent flow were compared. The CTRST was found to be more suitable for co-current flow. A prediction model pressure drop under co-current was established with an error of 15.5%.     

导向立体传质塔板在低温甲醇洗装置中开发应用

根据合成氨变换气脱硫塔扩产50%的要求,开发出一种导向立体传质塔板(CTST-8)。对导向立体传质塔板的流体力学性能研究表明,新塔板具有板压降低、气液二相通量大、抗堵塞、能消泡等技术特点。对扩产50%的低温甲醇洗脱硫塔内的水力学参数进行了核算,结果表明,扩产后的操作参数均处于导向立体传质塔板正常操作范围之内。将导向立体传质塔板应用于山西天脊集团变换气脱硫塔的扩产改造,达到了扩产50%的要求,取得了良好的效果。塔顶出口气相中φ(H2S)≤2×10-6,φ(CH3OH)≤3×10-4,全塔阻力小于0.08 MPa。