检索结果-南通市图书馆

A strategy for strengthening chaotic mixing of dual shaft eccentric mixers by changing non-Newtonian fluids kinetic energy distribution

引用

Chinese Journal of Chemical Engineering 2024年第5期69卷 122-134页

作者： Songsong Wang Tong Meng Qian Zhang Changyuan Tao Yundong Wang Zequan Li zuohua liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing 400044China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Efficiently modulating the velocity distribution and flow pattern of non-Newtonian fluids is a critical challenge in the context of dual shaft eccentric mixers for process intensification,posing a significant barrier for the existing ***,this work reports a convenient strategy that changes the kinetic energy to controllably regulate the flow patterns from radial flow to axial *** showed that the desired velocity distribution and flow patterns could be effectively obtained by varying the number and structure of baffles to change kinetic energy,and a more uniform velocity distribution,which could not be reached normally in standard baffle dual shaft mixers,was easily ***,a comparative analysis of velocity and shear rate distributions is employed to elucidate the mechanism behind the generation of flow patterns in various dual-shaft eccentric ***,there is little difference in the power number of the laminar flow at the same Reynolds number,meaning that the baffle type has no effect on the power consumption,while the power number of both unbaffle and U-shaped baffle mixing systems decreases compared with the standard baffle mixing system in the transition ***,at the same rotational condition,the dimensionless mixing time of the U-shaped baffle mixing system is 15.3%and 7.9%shorter than that of the standard baffle and the unbaffle mixing system,respectively,which shows the advantage of the U-shaped baffle in stirring rate.

关键词： Dual shaft “U-shaped”baffle Flow pattern Mixing time Power demand

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of aspect ratio of elliptical stirred vessel on mixing time and flow field characteristics in the absence of baffles

引用

Chinese Journal of Chemical Engineering 2024年第1期65卷 63-74页

作者： Yuan Yao Peiqiao liu Qian Zhang Zequan Li Benjun Xi Changyuan Tao Yundong Wang zuohua liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China Hubei Three Gorges Laboratory Yichang 443007China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks(USTs). Five different aspect ratios of elliptical vessels were designed to compare their mixing time and flow field. Computational fluid dynamics(CFD) simulations were performed using the k–ε model to calculate the mixing time and simulate turbulent flow field features, such as streamline shape, velocity distribution, vortex core region distribution, and turbulent kinetic energy(TKE) transfer. Visualization was also carried out to track the tinctorial evolution of the liquid phase. Results reveal that elliptical stirred tanks can significantly improve mixing performance in USTs. Specifically, the mixing time at an aspect ratio of 2.00 is only 45.3% of the one of a circular stirred tank. Furthermore, the secondary flow is strengthened and the vortex core region increases with the increase of aspect ratio. The axial velocity is more sensitive to the aspect ratio than the circumferential and radial velocity. Additionally, the TKE transfer in elliptical vessels is altered. These findings suggest that elliptical vessels offer a promising alternative to circular vessels for enhancing mixing performance in USTs.

关键词： Mixing time CFD Stirred tank Secondary flow Mixing performance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on cavern evolution and performance of three mixers in agitation of yield-pseudoplastic fluids

引用

Chinese Journal of Chemical Engineering 2023年第3期55卷 111-122页

作者： Songsong Wang Hong Li Changyuan Tao Renlong liu Yundong Wang zuohua liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China Graduate School Chongqing UniversityChongqing 400044China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing 400044China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

The hydrodynamic performance of three mixers single shaft central mixer(SSC), single shaft off-centred mixer(SSO), dual shaft off-centred mixer(DSO), was investigated in the mixing of yield-pseudoplastic fluids(xanthan gum solutions) in the laminar regime. To explore and determine the efficiency of three mixers, both numerical and experimental approaches were adopted. The fluid rheology was described by the Herschel–Bulkley rheological model. Computational fluid dynamics was employed to simulate the apparent viscosity distribution, mixing time, and the flow pattern inside the stirred tank. The developed model was validated through experimentally measured torque. The influence mechanism of the rotational speed and fluid rheology on the cavern evolution was explored deeply. The performances of three mixers in this work were compared at the constant power input and fluid rheology with respect to the flow pattern, mixing time, and mixing efficiency. The results verify that the faster the rotating speed, the greater influence of the fluid rheology on the cavern evolution, and the more uniform apparent viscosity distribution. Moreover, the mixing time decreases continuously as the increasing power consumption per unit volume, and the dimensionless mixing time of DSO mixer was nearly 42.8% and 6.1% shorter than that of SSC and SCO mixer at the same Reynolds number, respectively. According to the mixing efficiency criteria, these data also revealed that DSO was more efficient than SSC and SSO.

关键词： Cavern Apparent viscosity Mixing Yield-pseudoplastic fluids Computational fluid dynamics(CFD)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

后备母猪对人工光照强度的偏好性选择

引用

农业工程学报 2024年第7期40卷 269-276页

作者：葛绍娟郑炜超李修松王浩李保明曾雅琼胡彬龙定彪刘作华重庆市畜牧科学院国家生猪技术创新中心重庆402460 中国农业大学水利与土木工程学院北京100083 青岛大牧人机械股份有限公司青岛266041

为明确人工光环境下后备母猪的适宜光照强度,该研究搭建了一套猪舍光环境偏好性选择系统,以LED白光(400~700 nm)为人工光源,设置4种光照强度(40、100、350、1200 lx),每7 d为一个周期对单元猪舍对应的光照方案进行调整,光照时长16 h,以2... 详细信息

为明确人工光环境下后备母猪的适宜光照强度,该研究搭建了一套猪舍光环境偏好性选择系统,以LED白光(400~700 nm)为人工光源,设置4种光照强度(40、100、350、1200 lx),每7 d为一个周期对单元猪舍对应的光照方案进行调整,光照时长16 h,以24头二元杂交后备母猪为试验对象,进行了为期28 d的试验,探究后备母猪对人工光环境光照强度的偏好性选择规律。结果表明,在猪只数量的时空分布方面,相较于40、350、1200 lx,后备母猪在开灯期间表现出对100 lx光照强度的显著性偏好(P<0.05),占整体数量29.33%±1.14%;猪群对其余3种光照强度的偏好呈现明显的节律性,表现为开灯后和关灯前3 h对40 lx光照强度的偏好显著高于350、1200 lx(P<0.05);在猪只活跃度方面,开灯后的前6 h,较强光照组(350 lx:37.97%±3.47%和1200 lx:35.42%±4.04%)的猪只活跃度显著高于较弱光照组(40 lx:27.90%±8.44%和100 lx:23.94%±3.79%);在猪只采食方面,较强光照(350、1200 lx)组后备母猪的饲料消耗量和采食时长均高于较弱光照组(40、100 lx)。由此,建议后备母猪舍的照明制度中设置一定的光照过渡阶段,以100 lx光照强度为主,开灯后和关灯前3 h使用40 lx较弱光环境避免刺激,此外,可在09:00—11:00增加2 h较强光照(350 lx)增加猪只活动量。该研究结果可为后备母猪舍光环境精准调控提供理论参考依据。

关键词：猪光环境光照强度偏好性行为活跃度

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reduced power consumption in stirred vessel with high solid loading by equipping punched baffles

引用

Chinese Journal of Chemical Engineering 2023年第4期56卷 203-214页

作者： Xia Xiong zuohua liu Changyuan Tao Yundong Wang Fangqin Cheng Hong Li School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing 400044China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China Institute of Resources and Environment Engineering Shanxi UniversityTaiyuan 030006China Graduate School Chongqing UniversityChongqing 400044China

Solid-liquid suspension in stirred tank is a common operation in the chemical industry. The power consumption, flow pattern and flow field instability of three systems named as unbaffled stirred tank, traditional baffled stirred tank and punched baffled stirred tank(Pun-BST) were studied by using the computational fluid dynamic analysis. Results showed that perforating holes in the baffles could reduce power consumption of mixing. Meanwhile, the punched baffle system could maintain the solids in suspension as traditional baffle system. The results also showed that the baffles could increase the “effective flow” of stirred tank even though the whole velocity of the vessel is lower than un-baffled vessel. In addition, both the solid-liquid suspension and “effective flow” were related to instability of the flow *** solid-liquid suspension results always along with obvious instability of the flow field. But, the strengthening effect of punched baffle on flow field instability mainly happened in the near-wall ***'s because the collision and aggregation among sub-streams induced by holes intensified the unstable fluid flow. On the whole, the Pun-BST system provided much better mixing characteristics and recommended to apply in the industrial process.

关键词： Solid-liquid suspension Punched baffle Energy conservation Flow field instability Effective fluxion

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of aspect ratio of elliptical stirred vessel on mixing time and flow field characteristics in the absence of baffles

引用

Chinese Journal of Chemical Engineering 2024年第1期 63页

作者： Yuan Yao Peiqiao liu Qian Zhang Zequan Li Benjun Xi Changyuan Tao Yundong Wang zuohua liu

来源：博看期刊评论

在线全文

博看期刊

学校读者我要写书评

暂无评论

CFD simulation of hydrodynamics and mixing performance in dual shaft eccentric mixers

引用

Chinese Journal of Chemical Engineering 2023年第10期62卷 297-309页

作者： Songsong Wang Xia Xiong Peiqiao liu Qiongzhi Zhang Qian Zhang Changyuan Tao Yundong Wang zuohua liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing 400044China School of Mechanical and Transportation Engineering Chongqing UniversityChongqing 400044China Department of Chemical Engineering Tsinghua UniversityBeijing 100084China

This work aims to systematically study hydrodynamics and mixing characteristics of non-Newtonian fluid(carboxyl methyl cellulose,CMC)in dual shaft eccentric *** rheology was described by the power law rheological *** fluid dynamics was employed to simulate the velocity field and shear rate inside the stirred *** influence mechanism of the rotational modes,height difference between impellers,impeller eccentricities,and impeller types on the flow field have been well *** studied the performance of different dual-shaft eccentric mixers at the constant power input with its fluid velocity profiles,average shear strain rate,mixing time and mixing *** counter-rotation mode shows better mixing performance than co-rotation mode,and greater eccentricity can shorten mixing time on the basis of same stirred *** intensify the hydrodynamic interaction between impellers and enhance the overall mixing performance of the dual shaft eccentric mixers,it is critical to have a reasonable combination of impellers and an appropriate spatial position of impellers.

关键词： Dual shaft eccentric mixers Non-Newtonian fluid Mixing Laminar flow Computational fluid dynamics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhanced Mn^(2+)solidification and NH_(4)^(+)-N removal from electrolytic manganese metal residue via surfactants

引用

Chinese Journal of Chemical Engineering 2022年第9期35卷 205-212页

作者： Jiancheng Shu Xiangfei Zeng Danyang Sun Yong Yang zuohua liu Mengjun Chen Daoyong Tan School of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China

Electrolytic manganese metal residue(EMMR)harmless treatment has always lacked a low-cost and quick processing *** this study,surfactants,namely tetradecyl trimethylammonium chloride(TTC),sodium dodecyl benzene sulfonate(SDBS),sodium lignin sulfonate(SLS),and octadecyl trimethylammonium chloride(OTC),were used in the solidification of Mn^(2+)and removal of NH_(4)^(+)-N from *** Mn^(2+)and NH_(4)^(+)-N concentrations under different reaction conditions,Mn^(2+)solidification and NH_(4)^(+)-N removal mechanisms,and leaching behavior were *** results revealed that the surfactants could enhance the Mn^(2+)solidification and NH_(4)^(+)-N removal from EMMR,and the order of enhancement was as follows:TTC>SDBS>OTC>*** NH_(4)^(+)-N and Mn^(2+)concentrations were 12.3 and 0.05 mg·L^(-1)with the use of 60.0 mg·kg^(-1)TTC under optimum conditions(solid–liquid ratio of 1.5:1,EMMR to BRM mass ratio of 100:8,temperature of 20℃,and reaction duration of 12 h),which met the integrated wastewater discharge standard(GB8978-1996).Mn^(2+)was mainly solidified as Mn(OH)_(2),MnOOH and MnSiO_(3),and NH_(4)^(+)-N in EMMR was mostly removed in the form of *** results of this study could provide a new idea for cost-effective EMMR harmless treatment.

关键词： Electrolytic manganese metal residue Mn^(2+)solidification NH_(4)^(+)-N removal Surfactants

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

智慧化工背景下基于学科前沿视角的化工安全技术课程教学改革探析

引用

化工高等教育 2024年第1期41卷 29-36页

作者：刘作华李安琪王璐瑶姚远张骞陶长元重庆大学化学化工学院重庆401331 河南科技大学马克思主义学院河南洛阳471023

化工安全技术课程是化工专业的核心课程,具有综合性和实践性强的特点。但当前该课程教学仍存在教学内容陈旧、教学模式单一及安全操作训练不足等问题。对此,重庆大学绿色化学化工研究中心的课程教学团队基于学科前沿视角,实施了学术报... 详细信息

化工安全技术课程是化工专业的核心课程,具有综合性和实践性强的特点。但当前该课程教学仍存在教学内容陈旧、教学模式单一及安全操作训练不足等问题。对此,重庆大学绿色化学化工研究中心的课程教学团队基于学科前沿视角,实施了学术报告式前沿讨论、立体交叉实践式教学法、虚拟实景式智慧化工厂构建等教学改革举措,为培养既具备扎实化工基础又具有多学科交叉能力的复合型人才提供路径启示。

关键词：智慧化工化工安全技术学科前沿复合型人才

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

过程强化理论与装备研发相结合,提升研究生工程化意识

引用

广东化工 2024年第12期51卷 187-189,207页

作者：刘作华杨洁张骞陶长元范兴杜军刘仁龙李泽全李宏重庆大学化学化工学院重庆400044 重庆大学研究生院重庆400030

化学工业作为国民基础支柱产业,其重要性不言而喻,随着国外对诸多技术的垄断控制,国家迫切需要一批能满足国家和企业要求的高质量人才,一方面可以应用相关专业知识解决实际生产问题,另一方面,也要打破国外垄断、突破技术瓶颈,建立拥有... 详细信息

化学工业作为国民基础支柱产业,其重要性不言而喻,随着国外对诸多技术的垄断控制,国家迫切需要一批能满足国家和企业要求的高质量人才,一方面可以应用相关专业知识解决实际生产问题,另一方面,也要打破国外垄断、突破技术瓶颈,建立拥有自主知识产权的先进化工装备。过程强化理论与技术是化学工业中一个快速发展的重要研究方向,目前已经在诸多领域中得到了广泛应用。而化学反应过程涉及一系列复杂的非线性动力学知识,这就要求学生掌握牢固的理论基础,而另一方面,培养单位也需要瞄准国家重大战略需求开展相关研究生培养工作,例如各种新兴技术的工业化、产业化和市场化等。建设和发展与生产实践相适应的教学内容及课程体系,是教学改革的重要发展方向。本文提出以化工过程强化理论与装备研发相结合的教学理念,形成产教融合的发展模式,助力培养高层次化工人才的工程意识、创新能力和战略思维。

关键词：过程强化化学人才培养模式产教融合

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：