喷淋塔尾气除氨的实验研究

在喷淋吸收塔中,以氨气、空气、稀硝酸溶液为实验物系,通过条件试验,分别考察了喷淋密度、空塔气速、入口氨浓度、吸收液p H值及气液相温度对氨吸收率的影响。结果表明:氨吸收率随吸收液喷淋密度的增加而增大;增加空塔气速将导致氨吸收率下降;氨吸收率随吸收液p H值增大呈先下降后趋缓的趋势。p H值大于3时,p H值对吸收率影响不显著;入口氨浓度和气体温度对吸收率的影响较小;系统温度主要受液温控制,且吸收率随液体温度的升高而降低。     

喷淋塔氨法烟气脱硫模型与实验研究

在氨法烟气脱硫喷淋塔的实验系统上对影响氨法脱硫效率的几个主要因素进行了实验研究。实验结果表明：提高液气比和浆液pH值、降低烟气温度和烟气空塔气速均可以提高脱硫效率。在双膜理论的基础上,通过对氨法脱硫过程中SO₂传质速率方程和螺旋型喷嘴液滴直径大小关联式的分析,建立了喷淋塔氨法脱硫的数学模型。利用该模型对影响氨法脱硫效率的几个主要因素进行计算,并与实验结果进行比较,实验数据和模型计算值基本吻合。     

水力喷射空气旋流分离器脱氨

空气吹脱被广泛用于从废水中脱氨,但其过程效率有待提高。为了提高过程效率,提出了一种新型气-液吹脱设备——水力喷射空气旋流分离器（WSA）,并以废水中氨的吹脱进行了实验。与传统的吹脱设备相比,WSA表现出较好的气-液传质性能,使氨的吹脱效率大大提高。在氨的吹脱过程中,液相温度和空气流量是影响吹脱过程中氨体积传质系数的主要因素。空气流量对于体积传质系数存在一个临界值,超过此值时,体积传质系数随空气流量增加而迅速增大。液相中存在的固体颗粒物对于吹脱过程的传质几乎没有影响。在该设备中没有填料,不存在堵塞问题,因而可以进行较长时间的分离操作。     

喷淋塔氨法脱硫实验研究

文章在喷淋实验塔中,研究了氨法烟气脱硫的特性。将空气和气态二氧化硫按一定比例混合后的气体作为模拟烟气,用氨水作为脱除二氧化硫的吸收剂,对模拟烟气的进气温度、进气浓度、气速、液气比以及吸收液的pH五个因素对脱硫率的影响进行了逐一考察,获得了各因素与脱硫率之间的关系,并得到较适宜的操作参数。实验结果表明：随着液气比和吸收液pH的增大,脱硫率增大。随着模拟烟气进气温度、进气浓度和气速的增大,脱硫率降低。其中温度因素对脱硫率的影响不明显。实验得到适宜的操作参数为：常温下,模拟烟气气速为2．0m／s,液气比为10,pH为6．4时,对浓度为2000mg／m^3的烟气操作,收率可维持在85％以上,并在理论上对各因素和脱硫率之间的内在联系作了理论分析。     

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。     

填料塔气液传质参数研究（Ⅰ）──有效传质面积及容积传质系数

用化学吸收法测定了拉西环填料的有效传质表面积和容积传质系数，并进一步用物理法比较测定了容积传质系数。实验证明，用化学法测得的容积传质系数大于物理法测定值。并得出有效传质表面积及容积传质系数与喷淋密度的关系式。     

石灰石-石膏脱硫喷淋塔吸收区高度计算模型

从液滴受力分析入手,建立了喷淋塔的比表面积和传质速率方程,将吸收区划分为变速段与恒速段,推导了吸收区高度的计算模型,引用工业脱硫塔实际的工艺数据验证了模型的正确性,讨论了操作参数对吸收区高度的影响。结果表明,增加喷淋密度、提高吸收液pH值、减小液滴直径,均可降低吸收区高度;提高操作气速、增大烟气入口SO2浓度,吸收区高度增加;脱硫率随塔高而增加,但当脱硫率超过90%以后,增加塔高对脱硫率的影响不大。     

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。     

填料解吸塔中液相传质系数测定及电算程序设计

以填料解吸塔中N2解吸水中的O2含量为例,通过C lark复膜式极谱电极法测取有关数据,确定液相传质系数KL.A与喷淋密度L的关系,编制出FoxP ro源程序进行数据处理。     

Mass Transfer and Liquid‐Film Formation in a Spray Tower for SO2 Removal in Sodium Hydroxide Solution

Spray towers allow for controlling air pollution in which a liquid is sprayed in small droplets to produce a large interfacial area for mass transfer between a gas and a liquid phase. An experimental study of a spray tower for removing SO₂ is described. The experiments were carried out under different operating conditions by varying the gas velocity, liquid flow rate, and SO₂ concentration. SO₂ removal efficiency, volumetric mass transfer coefficient, and liquid‐film formation as a result of the collision of droplets against the tower wall are investigated. Removal efficiency and volumetric mass transfer coefficient are analyzed as a function of gas velocity, liquid flow rate, and SO₂ concentration, while liquid‐film formation is evaluated as a function of tower height. The results indicate high removal efficiency. Correlations to predict the volumetric mass transfer coefficient are also proposed.     

Performance of a UV‐assisted Hydrogen‐peroxide‐fed Spray Tower for Sulfur Dioxide Abatement

Spray towers are widely used for controlling air pollution by gases such as SO₂, CO₂, NO_x, and HCl. Results of sulfur dioxide absorption in a spray tower using solutions of 1 g L^–1 and 2 g L^–1 of hydrogen peroxide are reported. For comparison, a water and sodium hydroxide solution was also used for SO₂ abatement. The results indicate that H₂O₂ may be an important alternative for SO₂ removal in spray towers. A set of experimental removal efficiency data was obtained as a function of gas and liquid flow rates. Volumetric mass transfer coefficients (k_ga) were calculated and an experimental relationship among k_ga, gas, and liquid flow rates was proposed. As a final experiment, an oxidation process assisted by UV radiation using a 1 g L^–1 solution of H₂O₂ was carried out to speed up the SO₂ removal rate. The results obtained in this condition are similar to those achieved with a solution of 2 g L^–1 H₂O₂.     

SO2 Removal from Gas Streams by Ammonia Scrubbing: Process Optimization by Response Surface Methodology

Reduction of the SO₂ content by ammonia scrubbing in the incinerator of the Isfahan Refinery complex was investigated. An experimental continuous setup was designed to study the underlying process parameters affecting SO₂ capture from air. The effects of various parameters was analyzed by a systematic experimental design based on response surface methodology with central composite design. The developed response surface model was found to be useful and robust to predict the degree of desulfurization of ammonia wet flow gas disulfurization reactors. The ammonia concentration had the most significant influence on the efficiency of the desulfurization process. The square of temperature affected the efficiency more than the temperature, whereas the gas flow rate had a minor influence on the separation efficiency.     

一种新型湿法除尘脱硫装置在陶瓷工业中的应用

一种新型湿法除尘脱硫装置,可用于陶瓷工业喷雾干燥塔的除尘脱硫。采用4种方式六级除尘、内外双筒结构并带有自洁系统,能长期保持除尘能力。实践证明该设备造价低、维护简单、除尘效率高,可以二次脱硫,具有较好的推广前景。     

基于工业色谱仪的精馏脱炔烃塔软测量建模

提出一种基于工业色谱仪的软测量建模方法,并针对碳五馏分分离过程中的精馏脱炔烃塔塔底成分估计问题,建立了合适的工业软测量模型。介绍了工业色谱仪在线质量检测原理和LM-BP神经网络模型的建立,并利用工业色谱仪在线检测的质量数据进行系统的在线和周期性模型更新,提高了软测量模型的在线估计精度。研究结果表明,基于工业色谱仪的LM-BP神经网络模型是一种有效的软测量建模方法。     

Analysis on a Hydrophobic Hollow-Fiber Membrane Absorber and Experimental Observations of CO2 Removal by Enhanced Absorption

Abstract

In this paper an extended analysis on a hollow-fiber membrane absorber is conducted for CO₂ removal from flue gases. A rigorous model of gas–liquid mass transfer is developed on both narrow channels in and around the hollow fibers, including the gas absorption occurring from the reaction between CO₂ and aqueous K₂CO₃ absorbent. CO₂ concentration profiles can be obtained regardless of the placement of the flowing absorbent. Experimental observations of the CO₂ concentration in both the reject and permeate outlets compared with theoretical prediction allow us to understand the influence of flow rates of feed gas as well as absorbent on CO₂ absorption. For the flowing K₂CO₃ absorbent a kinetic constant can be chosen which will provide the best possible agreement between experiment and reactive model prediction. This fact emphasizes that the pseudofirst-order kinetic can be employed to describe the facilitation effect. The overall mass transfer coefficients were determined from the experimentally observed concentration changes. The CO₂ permeation flux was found to be enhanced as the K₂CO₃ concentration was increased, suggesting that CO₂ removal is entirely controlled by the reaction. The enhanced selectivity factor for CO₂/N₂, which decreases with increasing absorbent flow rate, reached as high as 1200 with 15 wt% K₂CO₃ absorbent.     

小合成氨厂碳丙脱碳综述

针对目前小合成氨厂碳丙脱碳存在的问题,详细分析了影响碳丙脱碳装置正常生产的因素,总结了90年代以来人们在解决生产实践中诸多问题的经验和方法,并碳丙脱碳工艺作了总结与评述。     

The Effect of Superficial Gas Velocity on Wavy Films and its Use in Enhancing the Performance of Falling Film Reactors

Mass transfer in co‐current downward annular flow depends on the amount of liquid carried by the waves. The thickness of this portion of the liquid film increases with the superficial gas velocity up to about 20–25 m s^–1 for two‐phase air/water flow. The maximum apparent friction factors observed in air‐water annular flow also appear at superficial air velocities about 20–25 m s^–1. Organic compounds, like fatty alcohols and alkylbenzenes, show a maximum apparent friction factor at lower superficial gas velocities. The gas velocity at which a maximum friction factor occurs is dependent on the surface tension, appearing at lower gas velocities for liquids with lower surface tensions. Progressive increases of the superficial gas velocity can be used to graduate the mass transfer along a falling film device.     

气体搅拌的萃取塔气—液—液系统流体力学性能和传质特性

１引言采用机械搅拌的萃取塔已广泛地应用在石油和化学工业生产中。近年来,一些研究学者又开发了用气体进行搅拌的萃取过程［１～３］,与机械搅拌相比,采用气体搅拌具有塔内无运动部件、操作稳定、结构简单、能耗低等特点,无疑给操作带来方便。如果在塔内装入静态混合...