干燥塔的技术改造

我公司硫酸生产线目前已达30 kt/a的生产规模.现用的干燥塔原设计能力为20 kt/a.生产中通过对干燥塔采用一系列国内先进的材料和技术进行改造,使其基本满足了当前的生产要求,但生产中一直存在塔阻力较大的问题.公司1997年对干燥塔的塔篦进行改造,3年来的运行结果表明这次技改是成功的.     

连续锦纶干燥塔的数学模型研究及数值仿真

针对某干燥塔的结构特点及运行过程中传热传质特性,建立了该干燥塔中干燥过程的传热传质微分模型,并用试验数据验证其合理性。运用经典龙格库塔法获得该模型的数值结果,分析了传热传质过程中干燥氮气温湿度和锦纶切片温湿度沿塔高的分布情况。通过仿真优化操作条件,提高了干燥塔的干燥能力。     

组合型干燥塔对氯化氢气体干燥的优点

浓硫酸具有吸收水的性能,但不同浓度下的浓硫酸,吸收水能力不同。本文主要阐述利用了不同浓度下浓硫酸的吸水能力差别,设计出的组合型干燥塔。并介绍了组合型干燥塔和填料塔、板塔相比,具有优良的性能和操作优点。     

填料塔与板式塔组合流程在氯气干燥中的应用

介绍外溢流泡沫干燥塔串联填料干燥塔工艺流程和填料干燥塔与填料泡罩复合干燥塔串联的工艺流程,结合南宁化工股份有限公司这两套装置的实际生产情况,指出:外溢流泡沫干燥塔串联填料干燥塔工艺流程投资少,操作相对复杂;填料干燥塔与填料泡罩复合干燥塔串联的工艺流程设备相对庞大,流程相对复杂,投资较多,但操作弹性大,运行平稳,二者都能较好地适应透平机的要求。     

300 kt/a硫黄制酸装置干燥塔阻力问题的处理

搬迁异地重建的300 kt/a硫黄制酸装置的一次化工投料成功运行74 d后,干燥塔出现阻力逐渐上升的趋势,最高约为18.5 kPa,严重影响装置的稳定运行。分析干燥塔阻力,对干燥塔进行更换填料和除沫器处理,技改后塔阻力和其他工艺指标恢复正常,装置能够满负荷平稳运行,达到预期效果。     

日产30t锦纶6切片水冷却式干燥塔结构简介

介绍了锦纶6切片工业装置中的一种水冷却式干燥塔的设计。与氮气冷却干燥装置相比,该设备省去了氮气冷却仓、氮气冷却器、氮气循环风机、粉尘过滤器、料住控制系统和大功率变频器等,设备成本下降,运行成本降低。     

强化型氯气泡沫干燥塔的设计与应用

介绍了强化型泡沫干燥塔适应国情、适合氯气干燥工艺的改造,具有“小投资、大回报”的特点。并简述了国内外氯气干燥工艺的优缺点,提出了强化型泡沫干燥塔在设计应用中的注意点以及推广强化型泡沫干燥塔的应用价值。     

高效氯气干燥塔工艺在氯气干燥中的应用

简述了氯气干燥原理。对比了高效氯气干燥塔工艺和多塔氯气干燥工艺的工艺流程，工艺指标和氯中含水控制值。说明：高效氯气干燥塔的应用操作弹性大、操作简单稳定、投资少、运行费用低、占地小、优势明显。     

均压稳流型分酸器在800 kt/a硫酸装置的应用

介绍了800 kt/a硫酸装置干燥塔分酸器运行情况及改造效果。针对管槽式分酸器落酸管腐蚀问题,技术人员采用了均压稳流型分酸器。该分酸器较好适应了装置干燥塔工况,耐腐蚀性能显著,分酸效果良好,使干燥空气水分、酸雾量、酸泵运行电流等均有所降低,确保了硫酸装置的长周期稳定运行。     

间歇冶炼工艺烟气制酸装置的设计

对间歇冶炼工艺烟气制酸装置的设计和操作进行了论述。为解决气体流量和SO_2浓度的波动问题,确保硫酸装置稳定运行,提出了各种解决方案,其中包括增设焚硫炉或预干燥塔、注入液体SO_2、采用一转一吸装置加尾气洗涤塔等。     

Determination of Spray-Drying Kinetics in a Small Scale

The main aim of the study presented in this article was to develop and test a method to determine spray-drying kinetics in a laboratory scale. A special measuring tunnel to obtain evaporation rate similar to the conditions observed in a spray-drying column was designed, built and tested.

Extensive studies of drying kinetics for maltodextrin were performed for different air flow rates and air temperatures. Test runs to determine repeatability of this technique showed satisfactory agreement between subsequent measurements, which confirms accuracy of the developed measuring method.

An effect of the initial moisture content on the critical moisture content was observed which is related to a decrease of the equilibrium vapor pressure over the solution and a decrease of the driving force of evaporation and drying rate of the process.

Results of the experiments proved that the generalized drying curve obtained from small-scale experiments could be used to describe spray-drying kinetics if the critical moisture content of the material is known.     

Determination of Spray-Drying Kinetics in a Small Scale

Abstract

The main aim of the study presented in this article was to develop and test a method to determine spray-drying kinetics in a laboratory scale. A special measuring tunnel to obtain evaporation rate similar to the conditions observed in a spray-drying column was designed, built and tested.

Extensive studies of drying kinetics for maltodextrin were performed for different air flow rates and air temperatures. Test runs to determine repeatability of this technique showed satisfactory agreement between subsequent measurements, which confirms accuracy of the developed measuring method.

An effect of the initial moisture content on the critical moisture content was observed which is related to a decrease of the equilibrium vapor pressure over the solution and a decrease of the driving force of evaporation and drying rate of the process.

Results of the experiments proved that the generalized drying curve obtained from small-scale experiments could be used to describe spray-drying kinetics if the critical moisture content of the material is known.     

喷雾干燥制备酯型儿茶素微胶囊

研究了用喷雾干燥法制备酯型儿茶素微胶囊的生产工艺。以酯型儿茶素为芯材,大豆色拉油为初级壁材,蛋白NP和碳水化合物CA、CB为壁材,经乳化剪切,喷雾干燥制得酯型儿茶素微胶囊。并获得了较优的工艺参数。在此基础上得到微胶囊的包埋率为76%。     

中药喷雾干燥技术的分析与研究进展

简要介绍了喷雾干燥研究状况,对喷雾雾化、液滴碰撞、湍流扩散、蒸发模型以及喷雾干燥工艺优化方面的研究作了回顾,同时对基于工程热物理理论的中药喷雾干燥技术作了阐述,指出了运用工程热物理的方法研究中药喷雾干燥技术的可行性和迫切性,为开展中药喷雾干燥技术的研究指明了方向。     

Application of Design of Experiments and Multilayer Perceptron Neural Network in Optimization of the Spray-Drying Process

The aim of this study was to investigate the effect of changing spray-drying parameters on the production of a naratriptan/maltodextrin/lactose composite, as well as to evaluate the application of design of experiments and multilayer perceptron (MLP) neural network in studying the spray-drying process. The system was spray dried as an aqueous solution using a Büchi 290-Mini Spray Dryer (Büchi Laboratoriums-Technik AG, Switzerland). A 2^4?1 factorial design study was undertaken to select the spray-drying processing variables that significantly affect the production yield, outlet air temperature, and residual moisture content. The process parameters studied were inlet air temperature, pump speed, aspirator setting (drying air flow rate), and feed concentration. After performing this screening study, three process parameters, pump speed, inlet air temperature, and feed concentration, were selected for further analysis, applying a central composite design and artificial neural network. Overall, the parameter that had the greatest influence on each investigated response was pump speed. It significantly influenced yield, moisture content, and particle size. Interaction between inlet air temperature and feed concentration was the only statistically significant interaction that influenced the moisture content. Particle size was mostly influenced by feed concentration as well as by a pump speed. A multilayer perceptron was the type of artificial neural network applied. The selected MLP structure had three layers: the first layer had three input units, the second layer had three hidden units, and the third layer had four output units. The selected MLP was trained through 10,000 epochs. Design of experiments using response surface methodology allows insight into interactions between variables, and an artificial neural network provides better prediction potential, enabling simultaneously determination of several outputs. Design of experiments and artificial neural network proved to be useful tool for optimization of the spray-drying process, where a design space for achieving the best process yields and optimum particle characteristics was established. There is a possibility that this conclusion can be drawn for other maltodextrin/lactose systems with other drug substances or for other similar spray-dried systems (the feedstock type is a carbohydrate-based aqueous solution). In future work, this will be tested with other materials.     

制备方法对Li1.2Ni0.17Co0.07Mn0.56O2富锂正极材料电化学性能的影响

采用喷雾干燥法、共沉淀法、固相法3种方法制备化学计量式为Li1.2Ni0.17Co0.07Mn0.56O2的锂离子电池富锂正极材料。电化学测试表明,喷雾干燥法制备的材料电化学性能最好,0.1 C充放电首圈脱锂和嵌锂容量分别为283.9 mA/(h?g)和231.7 mA/(h?g)。与共沉淀法和固相法相比较,喷雾干燥法制备的材料1 C倍率充放电时表现出良好的循环稳定性,50次循环后容量没有衰减,仍为153.4 mA/(h?g),共沉淀法和固相法制备的材料50次循环放电容量分别为133.5 mA/(h?g)和123.6 mA/(h?g)。ICP分析结果指出,喷雾干燥法制备的电极材料元素比例最符合初始的Li1.2Ni0.17Co0.07Mn0.56O2设计配比。而且喷雾干燥法制备的材料颗粒更为细小均匀,有利于提高材料的电化学性能。     

Kinetic models applied to soluble vitamins delivery systems prepared by spray drying

The incorporation of bioactive nutrient compounds such as vitamins into food systems can provide a simple way to develop new functional foods. In this work, the controlled release of two vitamins (vitamins B₁₂ and C), microencapsulated by a spray-drying process, is studied. With a properly designed controlled-release system, the compounds are released at the desired site and time, and at a desired rate. The main kinetic release models are applied and discussed. Also, the main mechanisms associated to the release were identified. The use of models to predict in vivo bio-performance is an advantage in the development of new products.     

并流喷雾干燥产品湿含量的控制

拟定了以料浆喷雾量FL为调节变量,控制气体出塔温度Tgf的反馈控制结构;建立了以Tgf为主要状态变量的过程动态模型,用于撞击流反应-沉淀法制超细白炭黑生产系统中喷雾干燥产品湿含量的控制。     

造纸废液喷雾干燥的工艺研究

为了解决造纸废液污染、有效利用废弃资源,以造纸废液为原料,采用喷雾干燥法制备木质素超细粉,在小试的基础上,对工业化制备条件及影响因素进行了讨论。确定出制备木质素超细粉的最佳工艺条件为:喷雾进料温度50—60℃、进料质量分数20%—25%、进风温度190℃、出风温度70℃、进料流量150 mL/m in、雾化压力2.3 MPa、喷嘴孔径0.8 mm,制得的木质素超细粉粒径为20—100 nm,比表面积37.8—455.6 m2/g。结果表明,采用喷雾干燥法处理造纸废液可得到木质素超细粉。     

Conditions for Accurate CFD Modeling of Spray-Drying Process

The paper presents concluding results of extensive experimental and theoretical research on confident CFD modeling of spray drying. An earlier developed experimental method to determine spray-drying kinetics in a lab scale allowed us to find a critical material moisture content and to determine generalized spray-drying curves. The generalized drying curves, identical in shape in the laboratory and pilot plant units, were used in the CFD model of spray drying process. Extensive simulations for spray drying of 10, 30, and 50% of initial solid content of maltodextrin proved high accuracy of the predictions of discrete (particle size distribution, particle moisture content, particle velocity, spray temperature) and continuous-phase parameters (gas temperature and humidity). Maximum error of the predictions of discrete-phase parameters was on the level of 20%, which is probably close to the current capacity of the CFD technique for modeling of spray-drying process. Comparison of experimental measurements and theoretical results shows that incorporation of realistic spray-drying kinetics into the CFD model and correct definition of initial drying and atomization parameters enable reliable simulations of spray-drying process.