检索结果-南通市图书馆

Study on the solid-liquid suspension behavior in a tank stirred by the long-short blades impeller

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第7期35卷 79-88页

作者： Zewen Chen Yongjun Wu Jian Wang peicheng luo School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Beijing System Engineering Institute Beijing 100034China CAS Key Laboratory Of Energy Regulation Materials Shanghai 200032China

We investigated the solid–liquid suspension characteristics in the tank with a liquid height/tank diameter ratio of 1.5 stirred by a novel long-short blades(LSB) impeller by the Euler granular flow model coupled with the standard k–ε turbulence model. After validation of the local solid holdup by experiments,numerical predictions have been successfully used to explain the influences of impeller rotating speed,particle density, particle size, liquid viscosity and initial solid loading on the solid suspension behavior,i.e. smaller particles with lower density are more likely to be suspended evenly in the liquid with higher liquid viscosity. At a low impeller rotating speed(N), increase in N leads to an obvious improvement in the solid distribution homogeneity. Moreover, the proposed LSB impeller has obvious advantages in the uniform distribution of the solid particles compared with single Rushton turbine(RT), dual RT impellers or CBY hydrofoil impeller under the same power consumption.

关键词： Two-phase flow Computational fluid dynamics Kinetic theory of granular flow Stirred tank Long-short blades impeller

Mixing times in single and multi-orifice-impinging transverse(MOIT) jet mixers with crossflow

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2016年第7期24卷 825-831页

作者： peicheng luo Yuncui Tai Yi Fang Hua Wu School of Chemistry & Chemical Engineering Southeast University Nanjing 211189 China Institute for Chemical and Bioengineering Department of Chemistry and Applied Bioscience ETH Zurich 8093 Zurich Switzerland

We study the macromixing behavior of single and multi-orifice-impinging transverse(MOIT) jet mixers with crossflow, in particular, the overall mixing time and the back-splash mixing time of the injected flow with the crossflow, using the PLIF technique. It is found that for a given mixer configuration, there is a critical jet-tocrossflow velocity ratio rcat which the back-splash begins to occur. Further increase in the velocity ratio r leads to sharp increase in the back-splash mixing time, which can offset the intensification of the downstream mixing. The dimensionless overall mixing time decreases as r increases to reach either a plateau or a local minimum, and the corresponding r value represents the optimal velocity ratio roptfor the macromixing. The momentum ratio of the two liquid streams is a key factor determining rcand ropt. For a larger scale mixer, a higher momentum ratio is required to achieve the optimal macromixing with the minimum dimensionless overall mixing time.

关键词： MixingChemical reactorsMixing timeJet mixerPlanar laser induced fluorescence (PLIF)

Effect of swirling addition on the liquid mixing performance in a T-jets mixer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2022年第10期50卷 108-116页

作者： Chunhui Li Bin Wu Junjie Zhang peicheng luo School of Chemistry and Chemical Engineering Southeast UniversityNanjing 211189China Hubei Sanjiang Aerospace Jianghe Chemical Technology Co. LtdYichang 444200China

Swirling addition to the stream is beneficial for the fluid *** work aims to study the mixing process intensification in a conventional T-jets mixer by the swirling *** experimental verification by the planar laser-induced fluorescence technique,large eddy simulation with the dynamic kinetic energy sub-grid stress model is used to predict how the swirling strength(in terms of swirling number,S_(w))and swirling directions affect the mixing performance,*** tracer concentration distribution,mixing time,and turbulent characteristics in the T-jets mixers,Predictions show that the swirling strength is the key factor affecting the mixing efficiency of the *** overall mixing time,τ_(90),can be significantly reduced by increasing S_(w).Vortex analysis shows that more turbulent eddies appear in the collision zone and the turbulent kinetic energy dissipation rate increases obviously with the swirling *** S_(w) is kept constant,the mixing process can be accelerated and intensified by adding swirling to only one stream,to both streams with the opposite swirling directions,or to both streams with the same swirling *** of the mixing process by enlarging the mixer size or increasing the flow rates is also ***,this work provides a new strategy to improve the mixing performance of the traditional T-jets mixers by the swirling addition.

关键词： Mixing T-jets mixer Swirling Computational fluiddynamics(CFD) Large eddysimulation

在线全文

学校读者我要写书评

暂无评论

氯化法钛白氧化反应器气体错流混合

化工学报 2006年第12期57卷 2840-2846页

作者：程易刘喆骆培成魏飞清华大学化学工程系

氧化反应器是氯化法制取钛白粉的关键设备,混合区的流场设计直接影响反应产品TiO2颗粒的质量(如粒径和粒径分布).利用无干扰流场测试技术——粒子图像测速仪(PIV)研究了不同气体错流混合区的结构设计对混合区域流场的影响,考察了气流动... 详细信息

氧化反应器是氯化法制取钛白粉的关键设备,混合区的流场设计直接影响反应产品TiO2颗粒的质量(如粒径和粒径分布).利用无干扰流场测试技术——粒子图像测速仪(PIV)研究了不同气体错流混合区的结构设计对混合区域流场的影响,考察了气流动量比、射流狭缝宽度以及射流角度对混合区流场的影响.结果表明,较大的气流动量比、窄射流狭缝宽度和接近90°的射流能获得更好的混合区速度分布.进一步利用计算流体力学(CFD)手段对相应的流场进行了模拟,与PIV实验结果吻合很好,验证了模型对冷态流动的预测能力.

关键词：氯化法钛白氧化反应器气体混合粒子图像测速仪计算流体力学

填料塔中碳酸钾/哌嗪混合吸收液脱除CO_2的体积传质系数

在线全文

学校读者我要写书评

暂无评论

化工学报 2005年第1期56卷 53-57页

作者：骆培成焦真张志炳南京大学化工系江苏南京210093

The process of removing dilute CO 2 from air by using the mixtures of K 2CO 3 and piperazine (PZ) was conducted in a random packed tower at 25 ℃.The results showed that PZ increased the absorption rate of CO 2 into aqueous K 2CO 3 much more effectively than MEA or DEA. The volumetric overall mass transfer coefficient (K Ga) of dilute CO 2 absorption into K 2CO 3/PZ was *** K Ga value was evaluated over the ranges of main operating variables: the concentration of CO 2 in inlet gas, gas flow rate, liquid loading, CO 2 loading in liquid phase,and the concentrations of K 2CO 3 and PZ. The test showed that K Ga could be remarkably improved by increasing liquid loading and the concentration of PZ, and decreasing the concentration of CO 2 in inlet gas, as well as the gas flow rate and CO 2 loading in liquid phase.

关键词：二氧化碳碳酸钾哌嗪填料塔体积总传质系数

多叶片组合式搅拌桨釜内流动特性和混合性能研究

在线全文

学校读者我要写书评

暂无评论

化工学报 2020年第11期71卷 4964-4970页

作者：许言王健武永军骆培成东南大学化学化工学院江苏南京211189 北京系统工程研究所北京100034

开发可适用于较宽黏度范围的搅拌桨,强化釜内的流体流动和混合过程对于搅拌釜的节能增效具有重要的意义。实验与数值模拟相结合,在大涡模拟层面研究了多叶片组合式搅拌桨(MBC桨)从层流到湍流状态下,釜内的功率特性、流场分布、湍流特性... 详细信息

开发可适用于较宽黏度范围的搅拌桨,强化釜内的流体流动和混合过程对于搅拌釜的节能增效具有重要的意义。实验与数值模拟相结合,在大涡模拟层面研究了多叶片组合式搅拌桨(MBC桨)从层流到湍流状态下,釜内的功率特性、流场分布、湍流特性和混合性能。结果表明:预测的功率曲线与实验结果一致;层流状态下釜内以切向流动为主,随着Reynolds数(Re)的增大,釜内轴向和径向流动逐渐增强,当Re达到486时,速度场分布与湍流状态下基本一致;在相同的能耗水平下,MBC桨对高黏度流体的混合性能优于商业Maxblend桨。桨叶的分散组合布置,强化了釜内的轴向和径向流动,使得MBC搅拌桨在从过渡流到湍流状态下均可实现较大的轴径向流动,湍动能分布较为均匀,混合过程显著加快。

关键词：混合多叶片组合式搅拌桨计算流体力学过渡流层流

面激光诱导荧光技术用于快速液液微观混合研究

在线全文

学校读者我要写书评

暂无评论

化工学报 2005年第12期56卷 2288-2293页

作者：骆培成程易汪展文金涌杨万宏清华大学化工系烟台万华聚氨酯股份有限公司山东烟台264002

建立了面激光诱导荧光技术研究液液微观混合过程的实验方法,在无干扰流场条件下,研究了毫米尺度流道内、错流接触的两股液膜的时空混合行为,以可视化的手段揭示了液液微观混合过程的二维瞬态浓度场,发现了液膜快速错流接触后形成的有序... 详细信息

建立了面激光诱导荧光技术研究液液微观混合过程的实验方法,在无干扰流场条件下,研究了毫米尺度流道内、错流接触的两股液膜的时空混合行为,以可视化的手段揭示了液液微观混合过程的二维瞬态浓度场,发现了液膜快速错流接触后形成的有序波形涡结构,涡的尺度大小为1～2mm,涡的发展过程是影响两股流体混合的主要因素.同时建立了混合过程的定量表征方法,用混合液膜中组分的离析度(intensityofsegregation,IOS)定量描述了混合过程所达到的程度,获得了不同液膜流速下液液混合过程IOS值随着液体流动方向的变化趋势图,并分析了两股液膜之间的速率比以及混合液膜的Reynolds数对混合过程的影响.

关键词：微观混合面激光诱导荧光技术无干扰流场测试技术波形涡离析度

在线全文

学校读者我要写书评

暂无评论

多孔错流喷射混合器内液体射流轨迹线

化工学报 2014年第7期65卷 2733-2740页

作者：骆培成吴俊辛传贤贾海燕东南大学化学化工学院江苏南京211189

利用平面激光诱导荧光测试技术对多孔错流喷射混合器内液体混合过程进行了研究,考察了操作条件(射流速度比r、混合流股Reynolds数ReM)和混合器的结构参数(射流小孔直径d、孔径管径比d/D、射流小孔个数n)对射流轨迹线的影响。结果表明,... 详细信息

利用平面激光诱导荧光测试技术对多孔错流喷射混合器内液体混合过程进行了研究,考察了操作条件(射流速度比r、混合流股Reynolds数ReM)和混合器的结构参数(射流小孔直径d、孔径管径比d/D、射流小孔个数n)对射流轨迹线的影响。结果表明,混合流股Reynolds数对射流轨迹线影响较小,射流速度比和混合器的结构参数是影响射流轨迹线的主要因素。建立了射流轨迹线的数学模型,并利用实验结果回归了模型参数。模型预测的液体混合过程射流轨迹线与实验结果基本吻合。

关键词：混合喷射混合器射流轨迹线激光诱导荧光模型

在线全文

学校读者我要写书评

暂无评论

一种计算混合过程尺度变化的新方法

东南大学学报（自然科学版） 2012年第6期42卷 1238-1242页

作者：骆培成辛传贤曹翠翠赵素青周建成东南大学化学化工学院南京211189

基于混合区域内子区域之间接触面的性质,提出了一种计算混合过程尺度指数和离析尺度的新方法.尺度指数可以定量表征混合过程中微团的尺度变化,反映了混合体系中微团离析尺度与计算尺度的差异.在一定的计算尺度下,当两组分(或两相)微团... 详细信息

基于混合区域内子区域之间接触面的性质,提出了一种计算混合过程尺度指数和离析尺度的新方法.尺度指数可以定量表征混合过程中微团的尺度变化,反映了混合体系中微团离析尺度与计算尺度的差异.在一定的计算尺度下,当两组分(或两相)微团互不接触时,尺度指数为1;当两组分(或两相)微团最大限度相互接触时,体系具有最小尺度指数0.对于特定的混合状态,计算尺度对离析指数的影响较大,在实际应用中计算尺度应小于体系内微团的最小尺度.根据一定计算尺度下尺度指数的计算结果,可以计算出特定混合状态下的离析尺度.离析尺度可以表征混合区域内相互离析的两组分(或两相)微团的尺度大小,反映了混合过程尺度降低的程度.

关键词：混合尺度变化定义尺度指数离析尺度