Modeling and Experimental Studies of Aqueous Suspension Polymerization Processes. 3. Mass-Transfer and Monomer Solubility Effects

1997 ◽  
Vol 36 (4) ◽  
pp. 1310-1321 ◽  
Author(s):  
Simon X. Zhang ◽  
W. Harmon Ray
Keyword(s):  
Mass Transfer ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Experimental Studies

STUDY OF EXTERNAL MASS TRANSFER DURING DRYING OF BERRY RAW MATERIALS TAKING INTO THE SHRINKAGE PHENOMENON

2019 ◽  
Author(s):  
А.В. АКУЛИЧ ◽  
Л.А. ГОСТИНЩИКОВА
Keyword(s):  
Mass Transfer ◽  
Energy Supply ◽  
Raw Materials ◽  
Mass Transfer Rate ◽  
Experimental Studies ◽  
Volume Shrinkage ◽  
External Mass Transfer ◽  
Transfer Coefficients ◽  
Ir Radiation ◽  
Criterial Equations

Исследованы закономерности внешнего массообмена при сушке ягодного сырья для различных способов энергоподвода. Установлено, что ягоды при сушке подвержены значительной объемной (72–81%) и линейной (35–43%) усадке, которую необходимо учитывать при расчете коэффициентов массоотдачи. Объекты исследования – ягоды черники, красной и черной смородины. Проведены экспериментальные исследования по сушке ягодного сырья при конвективном и конвективном с ИК-излучением способах энергоподвода. Исследования проведены при скорости сушильного агента хса1,2 м/с и температуре tса 70°С. Получены критериальные уравнения внешнего массоообмена при сушке ягод для периода постоянной скорости, учитывающие объемную усадку. Определено, что при сушке с конвективным энергоподводом объемная усадка при одном и том же значении критерия Рейнольдса оказывает на 12–20% большее влияние на интенсивность массоообмена для красной смородины по сравнению с черникой и черной смородиной. При сушке с конвективным энергоподводом, ИК-излучением и предварительным прокалыванием объемная усадка наиболее существенно влияет на массообмен для черной смородины, протекающий в 1,5–1,8 раза интенсивнее по сравнению с черникой и красной смородиной. Полученные критериальные уравнения могут быть использованы при расчете и проектировании установок для сушки ягодного сырья. The laws of external mass transfer during drying of berry raw materials for various methods of energy supply are investigated. It is established that the berries during drying are subject to significant volumetric (72–81%) and surface (35–43%) shrinkage, which must be taken into account when calculating the mass transfer coefficients. The objects of the study were various berries: blueberries, red and black currants. Experimental studies have been carried out on the drying of selected berries both in the case of convective and convective methods with IR radiation. Investigations were carried out at a drying agent velocity хса1,2 m/s and its temperature tca70°С. The criterion equations of external mass transfer during drying of berries for a period of constant speed, taking into account the volume shrinkage, are obtained. It was determined that during drying with convective energy supply, volume shrinkage with the same value of the Reynolds criterion on 12–20% has a greater effect on the mass transfer rate for red currants. When drying with convective energy supply, IR radiation and preliminary piercing, the volume shrinkage most significantly affects the mass transfer for black currants, which is 1,5–1,8 times more intense than blueberries and red currants. The obtained criterial equations can be used in the calculation and design of berries dryers.

Validation of the Pseudo Imprinted Microspheres for Solid-Phase Extraction of Acyclovir from Swine Tissue

2011 ◽  
Vol 393-395 ◽  
pp. 1591-1594
Author(s):  
Feng Xia Qiao ◽  
Hong Yuan Yan
Keyword(s):  
Solid Phase Extraction ◽  
Solid Phase ◽  
Suspension Polymerization ◽  
Aqueous Suspension ◽  
Selective Extraction ◽  
Phase Extraction ◽  
Matrix Interferences ◽  
The Matrix ◽  
Extraction Volume ◽  
Swine Tissue

The novel pseudo imprinted microspheres were synthesized by aqueous suspension polymerization using theophylline as the template and employed as a special sorbent of solid-phase extraction for selective extraction of acyclovir from swine tissue. The pseudo imprinted microspheres revealed high affinity and selectivity to acyclovir, and the matrix interferences could be efficiently eliminated, which make the extract of solid-phase extraction clean enough for HPLC analysis. The parameters that affect the extraction efficiency of solid-phase extraction were investigated, including solvent of extraction, volume of loading sample, washing and elution solvent, etc. Good linearity was obtained in a range of 0.05~15 μg/mL with correlation coefficient (r2) of 0.9991. The recoveries at three spiked levels were ranged from 91.4% to101.0% with RSD less than of 5.0%.

Experimental Study on Mass Transfer Coefficient of Dry Air in Main Cable of Suspension Bridge

2012 ◽  
Vol 461 ◽  
pp. 151-154
Author(s):  
Dai Yong Jia ◽  
Lu Yan Sui ◽  
Ming Lai He
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Experimental Studies ◽  
Suspension Bridge ◽  
Suspension Bridges ◽  
Dry Air ◽  
Experiment Platform ◽  
Main Cable ◽  
Key Parameter

In this study, an experiment platform was built up to determine the key parameter, mass transfer coefficient, of the ventilation and dehumidification process in main cable of suspension bridge. On the basis of experimental studies, an empirical formula of the mass transfer coefficient was obtained, which can greatly contribute to control the content of moisture in the main cable of suspension bridges.

scholarly journals Experimental studies and numerical modelling of heat and mass transfer process in shell-and-tube heat exchangers with compact arrangements of tube bundles

2018 ◽  
Vol 240 ◽  
pp. 02006 ◽  
Author(s):  
Valery Gorobets ◽  
Yurii Bohdan ◽  
Viktor Trokhaniak ◽  
Ievgen Antypov
Keyword(s):  
Mass Transfer ◽  
Numerical Modelling ◽  
Heat And Mass Transfer ◽  
Heat Exchangers ◽  
Experimental Studies ◽  
Mass Transfer Process ◽  
Experimental Investigations ◽  
Transfer Processes ◽  
Tube Bundles ◽  
Shell And Tube

Shall-and-tube heat exchangers based on the bundles with in-line or staggered arrangements have been widely used in industry and power engineering. A large number of theoretical and experimental works are devoted to study of hydrodynamic and heat transfer processes in such bundles. In that, works the basic studies of heat and mass transfer for these bundles are found. However, heat exchangers of this type can have big dimensions and mass. One of the ways to improve the weight and dimensions of the shell-and-tube heat exchangers is to use compact arrangement of tube bundles. A new design of heat exchanger is proposed, in which there are no gaps between adjacent tubes that touch each other. Different geometry of these tube bundles with displacement of adjacent tubes in the direction of transverse to the flow is considered. Numerical modelling and experimental investigations of hydrodynamic, heat and mass transfer processes in such tube bundles has been carried out. The distribution of velocities, temperatures, and pressure in inter-tube channels have been obtained.

Research on Heat and Mass Transfer of Flat Grooved Heat Pipes

2015 ◽  
Vol 733 ◽  
pp. 599-602
Author(s):  
Lei Cao ◽  
Guo Chang Zhao ◽  
Li Ping Song ◽  
Tian Dong Lu
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Temperature Control ◽  
Experimental Studies ◽  
Heat Pipes ◽  
Electronic Systems ◽  
Temperature Uniformity ◽  
Flat Surfaces ◽  
Flow And Heat Transfer ◽  
High Degree

Flat grooved heat pipes, which are especially useful in obtaining a high degree of temperature uniformity on flat surfaces, have been successfully used in the temperature control of electronic systems, however, the mechanisms governing the flow and heat transfer of this kind of heat pipes are still under scrutiny as some reported results cannot be reproduced by others or some assumptions have been proven to be unreasonable or ideal. The theoretical and experimental studies on flat grooved heat pipes and introduce work performed on modeling flat grooved heat pipes are reviewed in this paper.

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