新型空分填料的压降及模型预测比较

采用空气-水物系,在直径600 mm的有机玻璃塔中对杭州杭氧填料有限公司开发设计的HYTL-750Y型空分填料进行了压降测试。测试数据显示该新型规整填料通量大,压降小,是一种具有较优流体力学性能的空分填料。同时使用填料测试数据对SRPⅡ和Delft压降模型预测结果进行了评估和比较。结果显示,SRPⅡ模型可以较为准确的预测HYTL-750Y型空分填料预载区压降,而Delft模型预测压降和实验结果相差较大,预载区偏小,载点区偏大。对于整个操作范围内的压降预测,SRPⅡ模型和Delft模型都还需做进一步改进。     

几种开孔填料的性能研究(一)——流体力学性能

在直径600毫米的实验塔内,用空气-水体系对工业尺寸的金属阶梯环和环矩鞍填料进行了流体力学性能测试。得出在不同淋洒密度下每米填料层的压强降及泛点特性数据,对泛点填料因子和压降填料因子整理出关联式,供设计应用。 用相应尺寸的金属鲍尔环填料在同一设备中作了与该两种填料的性能对比试验。比较结果表明,金属阶梯环和金属环矩鞍填料的通量及压降性能明显地优于金属鲍尔环填料。     

开孔与层数对丝网波纹填料流体力学性能的影响

测定了单层无孔、双层无孔、单层开孔和双层开孔4种不同结构的金属丝网波纹填料的流体力学性能,以研究表面开孔和丝网层数对丝网波纹填料流体力学性能的影响。在直径100 mm的有机玻璃塔中使用空气-水体系对4种不同结构的金属丝网波纹填料进行了干填料压降、湿填料压降、泛点气速、持液量等流体力学性能测试。试验结果表明,4种丝网填料中双层开孔填料的干填料压降与湿填料压降低、泛点气速大、持液量适中,较其余3种填料流体力学性能更优秀。     

塑料扁环填料流体力学及传质性能的研究

在内径φ30 0 mm塔中 ,以空气 -氨 -水为物系 ,对塑料扁环填料的流体力学及传质性进行了研究。获得了该填料的几何特性、泛点填料因子ΦF、压降填料因子ΦP及气相传质单元高度 HOG与气相传质系数 KGa,该研究结果对设计有参考价值。     

φ25聚丙烯阶梯环填料流体力学性能研究

在直径为８０ｍｍ的有机玻璃塔内,以水－空气为介质对聚丙烯阶梯环填料流体力学性能进行研究,措出了填料层压降和空塔气速的变化关系,泛点气速和喷淋密度的关系。并依据实验数据关联出湿填料因子泛点填料因子和喷淋密度的经验式。     

Ф25聚丙烯阶梯环填料流体力学性能研究

在直径为８０ｍｍ的有机玻璃塔内，以水—空气为介质对聚丙烯阶梯环填料流体力学性能进行研究，找出了填料层压降和空塔气速的变化关系，泛点气速和喷淋密度的关系。并依据实验数据关联出湿填料因子、泛点填料因子和喷淋密度的经验式。     

塑料异型矩鞍填料的流体力学及传质性能研究

在内径300 mm塔中,以空气-氨-水为物系,对开发出的一种新型塑料散装填料———异型矩鞍填料的流体力学及传质性能进行了研究。获得了该填料的几何特性、流体力学性能及传质性能数据,并通过对实验数据的回归分析,得出了填料层压降Δp/Z、泛点填料因子F及气相总传质单元高度HOG的关联式。研究结果表明,塑料异型矩鞍填料具有通量大、压降低、气液分布均匀及传质性能优良等优点。     

交错型开窗导流填料的流体力学性能

为了提高规整填料通量,对传统开窗导流填料结构进行改善,提出一种新型交错式开窗导流填料。在不同喷淋密度下,采用空气-水系统对3种不同交错高度的开窗导流填料进行冷模实验,研究分析了其流体力学性能,并与传统开窗导流填料进行对比。实验结果表明:新型交错规整填料的压降随着喷淋密度的增加而增大,填料盘的交错式结构有效降低塔压降,提高通量,改善气液分布。与传统开窗导流填料相比,3种新型填料盘的干塔压降、湿塔压降显著降低,液泛气速显著提高。其中180-20型填料的压降降低最为显著,220-20型填料的液泛气速最低。同时,在LEVA模型和Bain-Hougen模型的基础上,获得了实验条件下干塔压降、湿塔压降和液泛气速的关联式,其计算结果与实验数据吻合较好。     

泡沫碳化硅波纹规整填料的流体力学及传质性能

将碳化硅陶瓷材料用于精馏过程,将该材料与波纹板类填料形状相结合开发出泡沫碳化硅波纹规整填料和光滑碳化硅波纹规整填料.对2种填料进行了流体力学性能与传质性能的测试,研究了泡沫结构对规整填料性能的影响.在直径100mm的有机玻璃塔中使用空气-水体系对填料进行干填料压降、湿填料压降、泛点气速、持液量等流体力学性能测试；在直径100mm的常压玻璃塔中,使用环己烷-正庚烷标准物系进行全回流操作,对填料进行传质性能测试.实验结果表明,在填料外形相同的情况下,与光滑填料相比,泡沫填料的干、湿填料压降较高,泛点气速相当,持液量增大,传质效率显著提高.     

NPJ—202异鞍填料试验报告

在φ600×6556毫米PVC塔中,对新开发的NPJ—202型瓷质异鞍填料(以下简称50毫米202异鞍)和50毫米瓷质矩鞍填料(以下简称50毫米矩鞍)进行了空气-水系统、空气-硫酸系统流体力学和传质性能对比研究。50毫米202异鞍与50毫米矩鞍相比较,压降平均低20～30％;泛点气速高12～19％;压降填料因子和泛点填料因子分别低20％和19％;传质性能略优。提出了50毫米202异鞍填料的压降、传质的计算关联式,供生产、设计使用。     

塑料星形填料流体力学与传质性能研究

在内径为100mm的填料塔内,以空气-水为物系,对新开发的塑料星形填料的流体力学和传质性能进行了测定.通过对实验数据的回归分析,推出了其填料层压降、液泛气速和液相总体积传质系数的关联式.     

CALCULATION PROCEDURE FOR FLOODING IN PACKED COLUMNS USING A CHANNEL MODEL

The combined effect of a channel-based approach for dry pressure drop and the Buchanan equation for wet pressure drop in packed beds has been numerically evaluated within the flooding region. The flooding point is an important design parameter since it establishes the maximum hydrodynamic capacity at which a packed column can operate. Upon analyzing the aforementioned approach, it was found that the usual practice of fixing a “reasonable” wet pressure drop at the flooding point (e.g., 1025 Pa/m) may not yield the correct flooding velocity of the gas, particularly at higher liquid loads. In fact, numerical evaluations of the aforementioned model showed a rather “retrograde” non-monotonic behavior of pressure drop with respect to the f factor of the gas near flooding at different liquid loads. A calculation procedure was therefore devised in this work to correctly compute the flooding point for a given liquid load when using the aforementioned modeling approach. Interestingly, it was found that the correct flooding velocity can be directly computed from liquid holdup below the gas loading point. To illustrate the use of the procedure, maximum capacity calculations were performed for a well-known random packing, a conventional structured packing, and a novel catalytic structured packing.     

一种适用于催化反应精馏的新型填料

为适应催化反应精馏填料需要高持液量及高效率的应用特点,开发了一种新型多层丝网填料PACTU-800,并通过设计中试装置对其进行了流体力学性能测试及传质性能测试。以空气-水为测试物系的冷模实验表明,F因子为0—0.55时,喷淋密度增大则压降增大,F>0.55时,压降变化没有明显规律;并经拟合得到泛点气速公式,与贝恩-霍根公式计算值相对误差为9.1%;以正庚烷-甲基环己烷为测试物系的热模实验表明:该填料理论板数较高,且F因子对其影响不大;F>2.3时,压降开始急剧增大。结果说明:PACTU-800操作弹性大,持液量大,适合高气液负荷下操作;其通量大,压降变化小,停留时间长,效率较高且较恒定。     

Simulation of hydrodynamic behaviour and mass transfer efficiency of reduced pressure distillation

A random packing hydrodynamic simulator is designed specially to carry out experiments under reduced pressures with a counter-current flow air/water system. The simulator results (air/water system) compared to those obtained in a real packed distillation column (benzylchloride/ ethylbenzene system) show a good agreement between hydrodynamic parameters like pressure drop, flooding flow rate, and total liquid hold-up. Empirical relationships derived from the simulator experimental results are proposed allowing the calculation of the pressure drop in a packed distillation column, operating in the pressure range between 10 kPa and atmospheric pressure. The influence of reduced pressure on the HETP in the distillation column and interfacial area in the simulator was also investigated.     

Mechanics of a turbulent contact absorber

The operating conditions of a turbulent contact absorber (TCA) can be divided into four regimes. The characteristic behaviour of a TCA in each of the regimes is discussed. The condition below the flooding point is the usual operating regime. Correlations are developed to relate the pressure drop and the liquid holdup of a TCA by the operating variables. A terminal velocity model is developed to explain the flooding condition of a TCA. With this model, the hydrodynamic behavior of the TCA at the flooding point can be identified. The total pressure drop and the pressure drop across a single stage are distinguished to clarify the controversy whether the gas velocity can affect the pressure drop of a TCA. The total pressure drop of a TCA is composed of the pressure drop due to distributor loss at the entrance and the pressure drop of the bed itself. The pressure drop of a single stage bed of a TCA is independent of gas velocity.     

Investigation of hydrodynamic performance and effective mass transfer area for Sulzer DX structured packing

The hydrodynamic performance in terms of pressure drop (?P) and liquid holdup (h_L), and tshe effective mass transfer area (a_e) of Sulzer DX structured packing were investigated at 293.15 K and 101.3 kPa. In addition, the flooding velocity (u_F) was also calculated based on the experimental results of liquid holdup, and the effective voidage correction factor (?) was obtained by combining the Billet model and the experimental effective fraction. The liquid volume method and pressure difference from just below to above the column packing approach are used to describe the hydrodynamic performance in a structured packing column. Experimental results showed that the operational conditions in terms of gas flow rate, liquid flow rate, viscosity, and liquid systems strongly affect the hydrodynamic performance. The experimental comparison between the pressure drop profiles in air‐water (polyethylene oxide [PEO]) and MEA‐H₂O‐CO₂ systems indicated that both the reacting MEA and CO₂ partial pressure can enhance the pressure drop value. In addition, the Bain‐Haugen correlation model was developed to predict the flooding velocity data with an acceptable AARD of 8.1%, and a model was also successfully proposed to predict the values of liquid holdup with an AARD of 11.8%, which is lower than 14.7% in Billet model. Furthermore, the effective mass transfer area was found to be increased by increasing both the liquid and gas flow rate by using NaOH‐H₂O‐CO₂ system. A model was also proposed to calculate the experimental a_e with an acceptable AARD% of 19.52, and this built model (Eq. 39) can reasonably explain the experimental phenomenon. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3625–3637, 2018     

金属θ环填料流体力学性能研究

在内径Φ=100mm的填料塔内,以空气-水为物系,对金属θ环的流体力学性能进行了测定。通过对实验数据的回归分析,推出了其填料层压降,泛点填料因子关联式,填料层持液量与气速的关系。该研究结果对金属θ环填料的工业应用有参考价值。     

催化蒸馏元件的流体力学性能

采用内径为206 mm的有机玻璃塔,在常温常压条件下,以空气和水为介质,对一种新型的反应液渗流式催化蒸馏元件进体力学实验研究,并研究了气相流通截面分率和固体催化剂在元件内装填高度对流体力学参数的影响;利用最小二乘法回归实验数据得到了床层压降、动持液量及泛点气速的预测关联式,各关联式误差均在±4.5%以内,可作为工业设计的参考依据。