scholarly journals Effect of Aspect Ratio on the Mixing Performance in the Kenics Static Mixer

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 464
Author(s):  
Xingren Jiang ◽  
Ning Yang ◽  
Rijie Wang

Continuous manufacturing has received increasing interest because of the advantages of intrinsic safety and enhanced mass transfer in the pharmaceutical industry. However, the difficulty for scale-up has limited the application of continuous manufacturing for a long time. Recently, the tubular flow reactor equipped with the Kenics static mixer appears to be a solution for the continuous process scale-up. Although many influence factors on the mixing performance in the Kenics static mixer have been investigated, little research has been carried out on the aspect ratio. In this study, we used the coefficient of variation as the mixing evaluation index to investigate the effect of the aspect ratio (0.2–2) on the Kenics static mixer’s mixing performance. The results indicate that a low aspect ratio helps obtain a shorter mixing time and mixer length. This study suggests that adjusting the aspect ratio of the Kenics static mixer can be a new strategy for the scale-up of a continuous process in the pharmaceutical industry.

2019 ◽  
Vol 8 (4) ◽  
pp. 139-161 ◽  
Author(s):  
Nada A Helal ◽  
Ola Elnoweam ◽  
Heba Abdullah Eassa ◽  
Ahmed M Amer ◽  
Mohamed Ashraf Eltokhy ◽  
...  

Continuous manufacturing (CM) has the potential to provide pharmaceutical products with better quality, improved yield and with reduced cost and time. Moreover, ease of scale-up, small manufacturing footprint and on-line/in-line monitoring and control of the process are other merits for CM. Regulating authorities are supporting the adoption of CM by pharmaceutical manufacturers through issuing proper guidelines. However, implementation of this technology in pharmaceutical industry is encountered by a number of challenges regarding the process development and quality assurance. This article provides a background on the implementation of CM in pharmaceutical industry, literature survey of the most recent state-of-the-art technologies and critically discussing the encountered challenges and its future prospective in pharmaceutical industry.


Author(s):  
D. Revathi ◽  
K. Saravanan

Mixing is the degree of homogeneity of two or more phases and it plays a vital role in the quality of the final product. It is conventionally carried out by mechanical agitators or by static mixers. Static mixers are a series of geometric mixing elements fixed within a pipe, which use the energy of the flow stream to create mixing between two or more fluids or to inject metered liquid into a continuous process. The objective of this work is to predict hydrodynamic aspects of the static mixer designed. The mixing performance of Komax static mixer has been determined for the blending of non-Newtonian fluid streams with identical or different rheology by using experimental study. The energy needed for mixing comes from the force created by the liquid due to turbulence and the geometry of the static mixer. Pressure drop in static mixer depend strongly on geometric arrangement of the inserts, properties of fluids to be mixed and flow conditions. Hence pressure drop studies are carried out for different flow rates of fluids with different concentrations of two non-Newtonian fluids. Starch and xanthan gum solutions are used as working fluids. It is observed from the experimental results that the pressure drop per unit length increases as the fluid flow rate increases and the nature of fluid flow varies with the velocity of the fluids.


Author(s):  
Spyridon Damilos ◽  
Ioannis Alissandratos ◽  
Luca Panariello ◽  
Anand N. P. Radhakrishnan ◽  
Enhong Cao ◽  
...  

AbstractA continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10–20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 oC and 2.3 bar(a) pressure. The use of a two-phase flow system – using heptane as the continuous phase – prevented fouling on the reactor walls, while improving the residence time distribution. Continuous syntheses for up to 2 h demonstrated its potential application for continuous manufacturing, while live quality control was established using online UV-Vis photospectrometry that monitored the particle size and process yield. The synthesis was stable and reproducible over time for gold precursor concentration above 0.23 mM (after mixing), resulting in average particle size between 12 and 15 nm. A hydrophobic membrane separator provided successful separation of the aqueous and organic phases and collection of colloidal Au NPs in flow. Process yield increased at higher inlet flow rates (from 70 % to almost 100 %), due to lower residence time of the colloidal solution in the separator resulting in less fouling in the PTFE membrane. This study addresses the challenges for the translation of the synthesis from batch to flow and provides tools for the development of a continuous manufacturing platform for gold nanoparticles.Graphical abstract


Author(s):  
Thomas Mainka ◽  
David Weirathmüller ◽  
Christoph Herwig ◽  
Stefan Pflügl

Abstract Saline wastewater contaminated with aromatic compounds can be frequently found in various industrial sectors. Those compounds need to be degraded before reuse of wastewater in other process steps or release to the environment. Halophiles have been reported to efficiently degrade aromatics, but their application to treat industrial wastewater is rare. Halophilic processes for industrial wastewater treatment need to satisfy certain requirements: a continuous process mode, low operational expenditures, suitable reactor systems and a monitoring and control strategy. The aim of this review is to provide an overview of halophilic microorganisms, principles of aromatic biodegradation, and sources of saline wastewater containing aromatics and other contaminants. Finally, process examples for halophilic wastewater treatment and potential process monitoring strategies are discussed. To further illustrate the significant potential of halophiles for saline wastewater treatment and to facilitate development of ready-to-implement processes, future research should focus on scale-up and innovative process monitoring and control strategies.


Author(s):  
Kelsey Fournier ◽  
Nancy Marina ◽  
Neeraj Joshi ◽  
Vincent R. Berthiaume ◽  
Sara Currie ◽  
...  

2018 ◽  
Vol 939 ◽  
pp. 197-204 ◽  
Author(s):  
Tobias Reincke ◽  
Sven Hartwig ◽  
Klaus Dilger

In comparison to monolithic composite structures, tailored multi-material structures offer high potential considering lightweight design approaches in combination with cost efficient manufacturing processes. Roll forming enables flexible large scale production of hybrid structures, due to the continuous manufacturing process as well as high degree of automation. The multi-material structures consist of steel sheets which are selectively reinforced by unidirectional carbon fibre reinforced thermoplastics (CFR-TP). In view of minimizing process steps and decreasing cycle times, both materials are joined by fusion bonding. Therefore, CFR-TP is heated above melting temperature of thermoplastic matrix and joined to the steel surface under defined pressure and time. However, joining of both materials within a continuous process is still challenging due to a lack in terms of process comprehension. Consequently, multi-material specimens were manufactured depending on various process parameters as temperature of either material or processing speed and tested mechanically by floating roller peel test for the evaluation of the adhesion between both materials. Furthermore, viscosity of matrix was determined and investigations of CFR-TP interface were performed by Fourier transform infrared spectroscopy. The results show the requirement of a defined CFR-TP temperature and the change in crystalline structure of the matrix in dependency of the processing.


2017 ◽  
Vol 13 ◽  
pp. 120-126 ◽  
Author(s):  
Christian H Hornung ◽  
Miguel Á Álvarez-Diéguez ◽  
Thomas M Kohl ◽  
John Tsanaktsidis

This work describes the Diels–Alder reaction of the naturally occurring substituted butadiene, myrcene, with a range of different naturally occurring and synthetic dienophiles. The synthesis of the Diels–Alder adduct from myrcene and acrylic acid, containing surfactant properties, was scaled-up in a plate-type continuous-flow reactor with a volume of 105 mL to a throughput of 2.79 kg of the final product per day. This continuous-flow approach provides a facile alternative scale-up route to conventional batch processing, and it helps to intensify the synthesis protocol by applying higher reaction temperatures and shorter reaction times.


2004 ◽  
Vol 49 (4) ◽  
pp. 13-18 ◽  
Author(s):  
C.S. Zalazar ◽  
M.D. Labas ◽  
C.A. Martín ◽  
R.J. Brandi ◽  
A.E. Cassano

A procedure to scale-up photoreactors employed in AOPs using laboratory information has been developed. Operating with a model compound the proposed procedure was applied to the decomposition of formic acid in water solution using hydrogen peroxide and UV radiation. With laboratory experiments the parameters of the kinetic equation were obtained in a small batch reactor operated within a recycling apparatus. The whole system was modeled employing radiation and mass balances. These balances were used together with a non-linear parameter estimator to derive the model kinetic constants. Then, these results were used in the modeling of the large-scale reactor to predict exit conversions in an isothermal, continuous, tubular flow reactor that is 2 m long and has a volume of 12 l. Once more, radiation and mass balances were used to predict formic acid output concentrations. Experimental data in the large-scale apparatus are in good agreement with theoretical predictions.


Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 835
Author(s):  
Tianyu Mao ◽  
Fengzhou Fang

The surface with high-aspect-ratio nanostructure is observed to possess the bactericidal properties, where the physical interaction between high-aspect-ratio nanostructure could exert sufficient pressure on the cell membrane eventually lead to cell lysis. Recent studies in the interaction mechanism and reverse engineering have transferred the bactericidal capability to artificial surface, but the biomimetic surfaces mimicking the topographical patterns on natural resources possess different geometrical parameters and surface properties. The review attempts to highlight the recent progress in bactericidal nanostructured surfaces to analyze the prominent influence factors and cell rupture mechanism. A holistic approach was utilized, integrating interaction mechanisms, material characterization, and fabrication techniques to establish inclusive insights into the topographical effect and mechano-bactericidal applications. The experimental work presented in the hydrogel material field provides support for the feasibility of potentially broadening applications in soft contact lenses.


2020 ◽  
Vol 10 (3) ◽  
pp. 1080 ◽  
Author(s):  
Qian Yu ◽  
Wim Brilman

Direct air capture (DAC) of CO2 can address CO2 emissions from distributed sources and produce CO2 from air virtually anywhere that it is needed. In this paper, the performance of a new radial flow reactor (RFR) for CO2 adsorption from ambient air is reported. The reactor uses a supported amine sorbent and is operated in a batch mode of operation or semi-continuously, respectively without or with sorbent circulation. The radial flow reactor, containing 2 kg of the adsorbent, is successfully scaled up from the experimental results obtained with a fixed bed reactor using only 1 g of the adsorbent. In the batch operation mode, the sorbent in the annular space of the RFR is regenerated in situ. With sorbent circulation, the RFR is loaded and unloaded batchwise and only used as an adsorber. A sorbent batch loaded with CO2 is transported to and regenerated in an external (fluid bed) regenerator. The RFR unit is characterized by a low contacting energy (0.7–1.5 GJ/ton-CO2) and a relatively short adsorption time (24–43 min) compared to other DAC processes using the same types of sorbents. The contactor concept is ready for further scale-up and continuous application.


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