检索结果-南通市图书馆

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

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

Experimental study of power consumption, local characteristics distributions and homogenization energy in gas–liquid stirred tank reactors

引用

Chinese Journal of Chemical Engineering 2019年第2期27卷 278-285页

作者： Facheng Qiu zuohua liu Renlong liu Xuejun Quan Changyuan Tao Yundong Wang School of Chemistry and Chemical Engineering Chongqing University School of Chemistry and Chemical Engineering Chongqing University of Technology Department of Chemical Engineering Tsinghua University

In this paper, the power consumption, the vertical local void fraction and the local gas–liquid interfacial area are investigated in the aerated stirred tank reactors(STRs) equipped with a rigid-flexible impeller. Meanwhile, the regressive correlation based on power consumption and interfacial area is proposed. Then a novel homogenization energy(HE = RSDPtm) expression based on power consumption and local interfacial area is redefined and used to indicate the mixing efficiency. The optimal operating mode is selected based on the change of the HE value. This paper can provide research ideas for structural optimization of stirred reactors.

关键词： Stirred tank Gas-liquid two-phase Power consumption Local characteristics Homogenization energy

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

An experimental study of immiscible liquid–liquid dispersions in a pump–mixer of mixer–settler

引用

Chinese Journal of Chemical Engineering 2020年第1期28卷 33-45页

作者： Qiao Tang Jiyizhe Zhang Yuxin Wu Yundong Wang zuohua liu State Key Laboratory of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China

Drop size distribution(DSD) or mean droplet size(d32) and liquid holdup are two key parameters in a liquid–liquid extraction process. Understanding and accurately predicting those parameters are of great importance in the optimal design of extraction columns as well as mixer–settlers. In this paper, the method of built-in endoscopic probe combined with pulse laser was adopted to measure the droplet size in liquid–liquid dispersions with a pump-impeller in a rectangular mixer. The dispersion law of droplets with holdup range 1% to 24% in batch process and larger flow ratio range 1/5 to 5/1 in continuous process was studied. Under the batch operation condition, the DSD abided by log-normal distribution. With the increase of impeller speed or decrease of dispersed phase holdup, the d32 decreased. In addition, a prediction model of d32 of kerosene/deionized system was established as d32/D = 0.13(1 + 5.9φ)We-0.6. Under the continuous operation condition, the general model for droplet size prediction of kerosene/water system was presented as d32/D = C3(1 + C4φ)We-0.6. For the surfactant system and extraction system, the prediction models met a general model as d32/D = bφnWe-0.6.

关键词： Dispersion Droplet size distribution Liquid–liquid Mean drop size Mixer–settler

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

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

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

A novel method for extracting vanadium by low temperature sodium roasting from converter vanadium slag

引用

Chinese Journal of Chemical Engineering 2020年第8期28卷 2208-2213页

作者： Rongrui Deng Hao Xiao Zhaoming Xie zuohua liu Qiang Yu Geng Chen Changyuan Tao College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Chemical Process for Clean Energy and Resource Utilization Chongqing 400044China

Long-term high temperature in conventional vanadium extraction process would cause particles to be sintered and wrapped, thus reducing extraction efficiency of vanadium. Based on the purpose of directional conversion and process intensification, this work proposed a combination of low temperature sodium roasting and high efficiency selective oxidation leaching in vanadium extraction. The investigation of the reaction mechanism suggested that the structure of vanadium slag was changed by roasting, which also caused the fracture of *** addition of MnO2 promoted the directional oxidation of low-valent vanadium into high valence. It also found that Na2S2O8 could oxidize low-valent vanadium effectively in leaching. The leaching efficiency of vanadium reached 87.74% under the optimum conditions, including a roasting temperature of 650 ℃, a roasting time of 2.0 h, a molar ratio of sodium-to-vanadium of 0.6, a MnO2(roasting additive) dosage of 5 wt% and a Na2S2O8(leaching oxidant) dosage of 5 wt%. This percentage is 7.18% higher than that of direct roasting-andleaching under the same conditions.

关键词： Directional conversion Oxidation leaching Process intensification Vanadium slag

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

Ionic liquid mediated CO_2 activation for DMC synthesis

引用

Journal of Natural Gas Chemistry 2012年第4期21卷 476-479页

作者： Jun Du Jing Shi Zhengfei Li zuohua liu Xing Fan Changyuan Tao College of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400030China

Promoted catalytic reaction between methanol and CO2 for dimethyl carbonate （DMC） synthesis is conducted over K2CO3/CH3I catalyst in the presence of ionic liquid under microwave irradiation. The effect of ionic liquids incorporated with microwave irradiation on the yield of DMC is investigated. DMC was found to form at lower temperature in a relative short time, which indicated an enhanced catalytic process by ionic liquid. Among the ionic liquids used, 1-butyl-3-methylimidazolium chloride is the most effective promoter. Density functional theory calculations indicate that CO2 bond lengths and angles changed due to the molecular interaction of ionic liquid and CO2, resulting in the activation of CO2 molecules and consequently the acceleration of reaction rate.

关键词： dimethyl carbonate direct synthesis microwave ionic liquids K2CO3/CH3I CO2

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

Effects of water-cooled cover on physiological and production parameters of farrowing sows under hot and humid climates

引用

International Journal of Agricultural and Biological Engineering 2016年第4期9卷 178-184页

作者： Pang Zhenzhen Li Baoming Zheng Weichao Lin Baozhong liu zuohua Department of Protected Agriculture Science and Engineering Hainan UniversityHainan 570228China Key Laboratory of Structure and Environment in Agricultural Engineering Ministry of AgricultureChina Agricultural UniversityBeijing 100083China Chongqing Academy of Animal Sciences Chongqing 402460China

The hot and humid climates,as encountered in the southern region of China with the open housing,can adversely impact the sows undergoing heat stress during the most vulnerable period at ***,a water-cooled cover system(WCCs)for local cooling has essential practical value to improve *** WCCs was developed for the sow crate of lactating sows separately,which performance was validated with the cooling efficiency in the sow occupied zone(SOZ)and physiological *** results showed that the WCCs for the farrowing sows using aluminium plastic tubes connected in series could reach an appropriate cooling performance in adjacent *** WCCs could decrease the SOZ air temperature by 3.0-4.5℃under the extremely hot climate when the indoor air temperature was 37℃,and maintain a suitable range(25-30℃)under the typical hot climate(<35℃).The respiration rate and skin temperature of farrowing sows had no significant difference between treatment group(WCC)and control group(sprinkle cooling)when the air temperature was below 30℃,but had a significant difference(p<0.05)when air temperature rose above 30℃.The control sows drank more during hot weather,and the feed intake was significantly lower than the sows with the WCCs(p<0.01).It was concluded that the WCCs could alleviate the heat stress of farrowing sows during typical hot climate.

关键词： localized cooling heat stress farrowing sow water-cooled cover hot and humid climate

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

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：